Merge remote-tracking branch 'origin/master' into 3283.backdoor-statement-signatures

.appveyor.yml

@@ -1,95 +0,0 @@
-# adapted from https://packaging.python.org/en/latest/appveyor/
-
-environment:
-
-  matrix:
-
-    # For Python versions available on Appveyor, see
-    # http://www.appveyor.com/docs/installed-software#python
-    - PYTHON: "C:\\Python27"
-    - PYTHON: "C:\\Python27-x64"
-    #  DISTUTILS_USE_SDK: "1"
-    #  TOX_TESTENV_PASSENV: "DISTUTILS_USE_SDK INCLUDE LIB"
-
-install:
-  - |
-    %PYTHON%\python.exe -m pip install -U pip
-    %PYTHON%\python.exe -m pip install wheel tox==3.9.0 virtualenv
-
-# note:
-# %PYTHON% has: python.exe
-# %PYTHON%\Scripts has: pip.exe, tox.exe (and others installed by bare pip)
-
-# We have a custom "build" system.  We don't need MSBuild or whatever.
-build: off
-
-# Do not build feature branch with open pull requests.  This is documented but
-# it's not clear it does anything.
-skip_branch_with_pr: true
-
-# This, perhaps, is effective.
-branches:
-  # whitelist
-  only:
-    - 'master'
-
-skip_commits:
- files:
-   # The Windows builds are unaffected by news fragments.
-   - 'newsfragments/*'
-   # Also, all this build junk.
-   - '.circleci/*'
-   - '.lgtm.yml'
-   - '.travis.yml'
-
-# we run from C:\projects\tahoe-lafs
-
-test_script:
-  # Put your test command here.
-  # Note that you must use the environment variable %PYTHON% to refer to
-  # the interpreter you're using - Appveyor does not do anything special
-  # to put the Python version you want to use on PATH.
-  - |
-    %PYTHON%\Scripts\tox.exe -e coverage
-    %PYTHON%\Scripts\tox.exe -e pyinstaller
-  # To verify that the resultant PyInstaller-generated binary executes
-  # cleanly (i.e., that it terminates with an exit code of 0 and isn't
-  # failing due to import/packaging-related errors, etc.).
-  - dist\Tahoe-LAFS\tahoe.exe --version
-
-after_test:
-  # This builds the main tahoe wheel, and wheels for all dependencies.
-  # Again, you only need build.cmd if you're building C extensions for
-  # 64-bit Python 3.3/3.4. And you need to use %PYTHON% to get the correct
-  # interpreter. If _trial_temp still exists, the "pip wheel" fails on
-  # _trial_temp\local_dir (not sure why).
-  - |
-    copy _trial_temp\test.log trial_test_log.txt
-    rd /s /q _trial_temp
-    %PYTHON%\python.exe setup.py bdist_wheel
-    %PYTHON%\python.exe -m pip wheel -w dist .
-  - |
-    %PYTHON%\python.exe -m pip install codecov "coverage ~= 4.5"
-    %PYTHON%\python.exe -m coverage xml -o coverage.xml -i
-    %PYTHON%\python.exe -m codecov -X search -X gcov -f coverage.xml
-
-artifacts:
-  # bdist_wheel puts your built wheel in the dist directory
-  # "pip wheel -w dist ." puts all the dependency wheels there too
-  # this gives us a zipfile with everything
-  - path: 'dist\*'
-  - path: trial_test_log.txt
-    name: Trial test.log
-  - path: eliot.log
-    name: Eliot test log
-
-on_failure:
-  # Artifacts are not normally uploaded when the job fails.  To get the test
-  # logs, we have to push them ourselves.
-  - ps: Push-AppveyorArtifact _trial_temp\test.log -Filename trial.log
-  - ps: Push-AppveyorArtifact eliot.log -Filename eliot.log
-
-#on_success:
-#  You can use this step to upload your artifacts to a public website.
-#  See Appveyor's documentation for more details. Or you can simply
-#  access your wheels from the Appveyor "artifacts" tab for your build.

.circleci/Dockerfile.centos

@@ -1,5 +1,6 @@
 ARG TAG
 FROM centos:${TAG}
+ARG PYTHON_VERSION
 
 ENV WHEELHOUSE_PATH /tmp/wheelhouse
 ENV VIRTUALENV_PATH /tmp/venv
@@ -11,11 +12,11 @@ RUN yum install --assumeyes \
     git \
     sudo \
     make automake gcc gcc-c++ \
-    python \
+    python${PYTHON_VERSION} \
-    python-devel \
+    python${PYTHON_VERSION}-devel \
     libffi-devel \
     openssl-devel \
-    libyaml-devel \
+    libyaml \
     /usr/bin/virtualenv \
     net-tools
 
@@ -23,4 +24,4 @@ RUN yum install --assumeyes \
 # *update* this checkout on each job run, saving us more time per-job.
 COPY . ${BUILD_SRC_ROOT}
 
-RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python2.7"
+RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python${PYTHON_VERSION}"

.circleci/Dockerfile.debian

@@ -1,5 +1,6 @@
 ARG TAG
 FROM debian:${TAG}
+ARG PYTHON_VERSION
 
 ENV WHEELHOUSE_PATH /tmp/wheelhouse
 ENV VIRTUALENV_PATH /tmp/venv
@@ -12,8 +13,8 @@ RUN apt-get --quiet update && \
         lsb-release \
         sudo \
         build-essential \
-	python2.7 \
+        python${PYTHON_VERSION} \
-    	python2.7-dev \
+        python${PYTHON_VERSION}-dev \
         libffi-dev \
         libssl-dev \
         libyaml-dev \
@@ -23,7 +24,7 @@ RUN apt-get --quiet update && \
 # *update* this checkout on each job run, saving us more time per-job.
 COPY . ${BUILD_SRC_ROOT}
 
-RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python2.7"
+RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python${PYTHON_VERSION}"
 
 # Only the integration tests currently need this but it doesn't hurt to always
 # have it present and it's simpler than building a whole extra image just for

.circleci/Dockerfile.fedora

@@ -1,5 +1,6 @@
 ARG TAG
 FROM fedora:${TAG}
+ARG PYTHON_VERSION
 
 ENV WHEELHOUSE_PATH /tmp/wheelhouse
 ENV VIRTUALENV_PATH /tmp/venv
@@ -11,8 +12,8 @@ RUN yum install --assumeyes \
     git \
     sudo \
     make automake gcc gcc-c++ \
-    python \
+    python${PYTHON_VERSION} \
-    python-devel \
+    python${PYTHON_VERSION}-devel \
     libffi-devel \
     openssl-devel \
     libyaml-devel \
@@ -23,4 +24,4 @@ RUN yum install --assumeyes \
 # *update* this checkout on each job run, saving us more time per-job.
 COPY . ${BUILD_SRC_ROOT}
 
-RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python2.7"
+RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python${PYTHON_VERSION}"

.circleci/Dockerfile.pypy

@@ -1,4 +1,4 @@
-FROM pypy:2.7-7.1.1-jessie
+FROM pypy:2.7-buster
 
 ENV WHEELHOUSE_PATH /tmp/wheelhouse
 ENV VIRTUALENV_PATH /tmp/venv

.circleci/Dockerfile.slackware

@@ -1,49 +0,0 @@
-ARG TAG
-FROM vbatts/slackware:${TAG}
-
-ENV WHEELHOUSE_PATH /tmp/wheelhouse
-ENV VIRTUALENV_PATH /tmp/venv
-# This will get updated by the CircleCI checkout step.
-ENV BUILD_SRC_ROOT /tmp/project
-
-# Be careful with slackpkg.  If the package name given doesn't match anything,
-# slackpkg still claims to succeed but you're totally screwed.  Slackware
-# updates versions of packaged software so including too much version prefix
-# is a good way to have your install commands suddenly begin not installing
-# anything.
-RUN slackpkg update && \
-    slackpkg install \
-        openssh-7 git-2 \
-        ca-certificates \
-        sudo-1 \
-        make-4 \
-        automake-1 \
-        kernel-headers \
-        glibc-2 \
-        binutils-2 \
-        gcc-5 \
-        gcc-g++-5 \
-        python-2 \
-        libffi-3 \
-        libyaml-0 \
-        sqlite-3 \
-        icu4c-56 \
-        libmpc-1 </dev/null && \
-    slackpkg upgrade \
-        openssl-1 </dev/null
-
-# neither virtualenv nor pip is packaged.
-# do it the hard way.
-# and it is extra hard since it is slackware.
-RUN slackpkg install \
-        cyrus-sasl-2 \
-        curl-7 </dev/null && \
-    curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py && \
-    python get-pip.py && \
-    pip install virtualenv
-
-# Get the project source.  This is better than it seems.  CircleCI will
-# *update* this checkout on each job run, saving us more time per-job.
-COPY . ${BUILD_SRC_ROOT}
-
-RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python2.7"

.circleci/Dockerfile.ubuntu

@@ -1,5 +1,6 @@
 ARG TAG
 FROM ubuntu:${TAG}
+ARG PYTHON_VERSION
 
 ENV WHEELHOUSE_PATH /tmp/wheelhouse
 ENV VIRTUALENV_PATH /tmp/venv
@@ -13,8 +14,8 @@ RUN apt-get --quiet update && \
     apt-get --quiet --yes install \
         sudo \
         build-essential \
-        python2.7 \
+        python${PYTHON_VERSION} \
-        python2.7-dev \
+        python${PYTHON_VERSION}-dev \
         libffi-dev \
         libssl-dev \
         libyaml-dev \
@@ -26,4 +27,4 @@ RUN apt-get --quiet update && \
 # *update* this checkout on each job run, saving us more time per-job.
 COPY . ${BUILD_SRC_ROOT}
 
-RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python2.7"
+RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}" "python${PYTHON_VERSION}"

.circleci/config.yml

@@ -1,44 +1,86 @@
 # https://circleci.com/docs/2.0/
 
-version: 2
+# We use version 2.1 of CircleCI's configuration format (the docs are still at
+# the 2.0 link) in order to have access to Windows executors. This means we
+# can't use dots in job names anymore. They have a new "parameters" feature
+# that is supposed to remove the need to have version numbers in job names (the
+# source of our dots), but switching to that is going to be a bigger refactor:
+#
+#   https://discuss.circleci.com/t/v2-1-job-name-validation/31123
+#   https://circleci.com/docs/2.0/reusing-config/
+#
+version: 2.1
+
 workflows:
-  version: 2
   ci:
     jobs:
-      # Platforms
+      # Start with jobs testing various platforms.
-      - "debian-9"
+
+      # Every job that pulls a Docker image from Docker Hub needs to provide
+      # credentials for that pull operation to avoid being subjected to
+      # unauthenticated pull limits shared across all of CircleCI.  Use this
+      # first job to define a yaml anchor that can be used to supply a
+      # CircleCI job context which makes Docker Hub credentials available in
+      # the environment.
+      #
+      # Contexts are managed in the CircleCI web interface:
+      #
+      #  https://app.circleci.com/settings/organization/github/tahoe-lafs/contexts
+      - "debian-9": &DOCKERHUB_CONTEXT
+          context: "dockerhub-auth"
+
       - "debian-8":
+          <<: *DOCKERHUB_CONTEXT
           requires:
             - "debian-9"
 
-      - "ubuntu-18.04"
+      - "ubuntu-20-04":
-      - "ubuntu-16.04":
+          <<: *DOCKERHUB_CONTEXT
+      - "ubuntu-18-04":
+          <<: *DOCKERHUB_CONTEXT
           requires:
-            - "ubuntu-18.04"
+            - "ubuntu-20-04"
+      - "ubuntu-16-04":
+          <<: *DOCKERHUB_CONTEXT
+          requires:
+            - "ubuntu-20-04"
 
-      - "fedora-29"
+      - "fedora-29":
+          <<: *DOCKERHUB_CONTEXT
       - "fedora-28":
+          <<: *DOCKERHUB_CONTEXT
           requires:
             - "fedora-29"
 
-      - "centos-7"
+      - "centos-8":
+          <<: *DOCKERHUB_CONTEXT
 
-      - "slackware-14.2"
+      - "nixos-19-09":
+          <<: *DOCKERHUB_CONTEXT
 
-      - "nixos-19.09"
+      # Test against PyPy 2.7
+      - "pypy27-buster":
+          <<: *DOCKERHUB_CONTEXT
 
-      # Test against PyPy 2.7/7.1.1
+      # Just one Python 3.6 configuration while the port is in-progress.
-      - "pypy2.7-7.1"
+      - "python36":
+          <<: *DOCKERHUB_CONTEXT
 
       # Other assorted tasks and configurations
-      - "lint"
+      - "lint":
-      - "pyinstaller"
+          <<: *DOCKERHUB_CONTEXT
-      - "deprecations"
+      - "pyinstaller":
-      - "c-locale"
+          <<: *DOCKERHUB_CONTEXT
+      - "deprecations":
+          <<: *DOCKERHUB_CONTEXT
+      - "c-locale":
+          <<: *DOCKERHUB_CONTEXT
       # Any locale other than C or UTF-8.
-      - "another-locale"
+      - "another-locale":
+          <<: *DOCKERHUB_CONTEXT
 
       - "integration":
+          <<: *DOCKERHUB_CONTEXT
           requires:
             # If the unit test suite doesn't pass, don't bother running the
             # integration tests.
@@ -46,7 +88,8 @@ workflows:
 
       # Generate the underlying data for a visualization to aid with Python 3
       # porting.
-      - "build-porting-depgraph"
+      - "build-porting-depgraph":
+          <<: *DOCKERHUB_CONTEXT
 
   images:
     # Build the Docker images used by the ci jobs.  This makes the ci jobs
@@ -61,21 +104,55 @@ workflows:
                 - "master"
 
     jobs:
-      - "build-image-debian-8"
+      - "build-image-debian-8":
-      - "build-image-debian-9"
+          <<: *DOCKERHUB_CONTEXT
-      - "build-image-ubuntu-16.04"
+      - "build-image-debian-9":
-      - "build-image-ubuntu-18.04"
+          <<: *DOCKERHUB_CONTEXT
-      - "build-image-fedora-28"
+      - "build-image-ubuntu-16-04":
-      - "build-image-fedora-29"
+          <<: *DOCKERHUB_CONTEXT
-      - "build-image-centos-7"
+      - "build-image-ubuntu-18-04":
-      - "build-image-slackware-14.2"
+          <<: *DOCKERHUB_CONTEXT
-      - "build-image-pypy-2.7-7.1.1-jessie"
+      - "build-image-ubuntu-20-04":
+          <<: *DOCKERHUB_CONTEXT
+      - "build-image-fedora-28":
+          <<: *DOCKERHUB_CONTEXT
+      - "build-image-fedora-29":
+          <<: *DOCKERHUB_CONTEXT
+      - "build-image-centos-8":
+          <<: *DOCKERHUB_CONTEXT
+      - "build-image-pypy27-buster":
+          <<: *DOCKERHUB_CONTEXT
+      - "build-image-python36-ubuntu":
+          <<: *DOCKERHUB_CONTEXT
 
 
 jobs:
+  dockerhub-auth-template:
+    # This isn't a real job.  It doesn't get scheduled as part of any
+    # workflow.  Instead, it's just a place we can hang a yaml anchor to
+    # finish the Docker Hub authentication configuration.  Workflow jobs using
+    # the DOCKERHUB_CONTEXT anchor will have access to the environment
+    # variables used here.  These variables will allow the Docker Hub image
+    # pull to be authenticated and hopefully avoid hitting and rate limits.
+    docker: &DOCKERHUB_AUTH
+      - image: "null"
+        auth:
+          username: $DOCKERHUB_USERNAME
+          password: $DOCKERHUB_PASSWORD
+
+    steps:
+      - run:
+          name: "CircleCI YAML schema conformity"
+          command: |
+            # This isn't a real command.  We have to have something in this
+            # space, though, or the CircleCI yaml schema validator gets angry.
+            # Since this job is never scheduled this step is never run so the
+            # actual value here is irrelevant.
+
   lint:
     docker:
-      - image: "circleci/python:2"
+      - <<: *DOCKERHUB_AUTH
+        image: "circleci/python:2"
 
     steps:
       - "checkout"
@@ -92,7 +169,8 @@ jobs:
 
   pyinstaller:
     docker:
-      - image: "circleci/python:2"
+      - <<: *DOCKERHUB_AUTH
+        image: "circleci/python:2"
 
     steps:
       - "checkout"
@@ -117,7 +195,8 @@ jobs:
 
   debian-9: &DEBIAN
     docker:
-      - image: "tahoelafsci/debian:9"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/debian:9-py2.7"
         user: "nobody"
 
     environment: &UTF_8_ENVIRONMENT
@@ -140,6 +219,8 @@ jobs:
       # we maintain.
       WHEELHOUSE_PATH: &WHEELHOUSE_PATH "/tmp/wheelhouse"
       PIP_FIND_LINKS: "file:///tmp/wheelhouse"
+      # Upload the coverage report.
+      UPLOAD_COVERAGE: "yes"
 
     # pip cannot install packages if the working directory is not readable.
     # We want to run a lot of steps as nobody instead of as root.
@@ -188,26 +269,32 @@ jobs:
       - run: &SUBMIT_COVERAGE
           name: "Submit coverage results"
           command: |
+            if [ -n "${UPLOAD_COVERAGE}" ]; then
               /tmp/venv/bin/codecov
+            fi
 
 
   debian-8:
     <<: *DEBIAN
     docker:
-      - image: "tahoelafsci/debian:8"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/debian:8-py2.7"
         user: "nobody"
 
 
-  pypy2.7-7.1:
+  pypy27-buster:
     <<: *DEBIAN
     docker:
-      - image: "tahoelafsci/pypy:2.7-7.1.1-jessie"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/pypy:buster-py2"
         user: "nobody"
 
     environment:
       <<: *UTF_8_ENVIRONMENT
-      TAHOE_LAFS_TOX_ENVIRONMENT: "pypy27-coverage"
+      # We don't do coverage since it makes PyPy far too slow:
-      ALLOWED_FAILURE: "yes"
+      TAHOE_LAFS_TOX_ENVIRONMENT: "pypy27"
+      # Since we didn't collect it, don't upload it.
+      UPLOAD_COVERAGE: ""
 
 
   c-locale:
@@ -236,6 +323,8 @@ jobs:
       TAHOE_LAFS_TOX_ENVIRONMENT: "deprecations,upcoming-deprecations"
       # Put the logs somewhere we can report them.
       TAHOE_LAFS_WARNINGS_LOG: "/tmp/artifacts/deprecation-warnings.log"
+      # The deprecations tox environments don't do coverage measurement.
+      UPLOAD_COVERAGE: ""
 
 
   integration:
@@ -255,23 +344,50 @@ jobs:
       - run: *RUN_TESTS
 
 
-  ubuntu-16.04:
+  ubuntu-16-04:
     <<: *DEBIAN
     docker:
-      - image: "tahoelafsci/ubuntu:16.04"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/ubuntu:16.04-py2.7"
         user: "nobody"
 
 
-  ubuntu-18.04:
+  ubuntu-18-04: &UBUNTU_18_04
     <<: *DEBIAN
     docker:
-      - image: "tahoelafsci/ubuntu:18.04"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/ubuntu:18.04-py2.7"
         user: "nobody"
 
 
-  centos-7: &RHEL_DERIV
+  python36:
+    <<: *UBUNTU_18_04
     docker:
-      - image: "tahoelafsci/centos:7"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/ubuntu:18.04-py3"
+        user: "nobody"
+
+    environment:
+      <<: *UTF_8_ENVIRONMENT
+      # The default trial args include --rterrors which is incompatible with
+      # this reporter on Python 3.  So drop that and just specify the
+      # reporter.
+      TAHOE_LAFS_TRIAL_ARGS: "--reporter=subunitv2-file"
+      TAHOE_LAFS_TOX_ENVIRONMENT: "py36-coverage"
+
+
+  ubuntu-20-04:
+    <<: *DEBIAN
+    docker:
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/ubuntu:20.04"
+        user: "nobody"
+
+
+  centos-8: &RHEL_DERIV
+    docker:
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/centos:8-py2"
         user: "nobody"
 
     environment: *UTF_8_ENVIRONMENT
@@ -293,41 +409,24 @@ jobs:
   fedora-28:
     <<: *RHEL_DERIV
     docker:
-      - image: "tahoelafsci/fedora:28"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/fedora:28-py"
         user: "nobody"
 
 
   fedora-29:
     <<: *RHEL_DERIV
     docker:
-      - image: "tahoelafsci/fedora:29"
+      - <<: *DOCKERHUB_AUTH
+        image: "tahoelafsci/fedora:29-py"
         user: "nobody"
 
 
-  slackware-14.2:
+  nixos-19-09:
-    docker:
-      - image: "tahoelafsci/slackware:14.2"
-        user: "nobody"
-
-    environment: *UTF_8_ENVIRONMENT
-
-    # pip cannot install packages if the working directory is not readable.
-    # We want to run a lot of steps as nobody instead of as root.
-    working_directory: "/tmp/project"
-
-    steps:
-      - "checkout"
-      - run: *SETUP_VIRTUALENV
-      - run: *RUN_TESTS
-      - store_test_results: *STORE_TEST_RESULTS
-      - store_artifacts: *STORE_TEST_LOG
-      - store_artifacts: *STORE_OTHER_ARTIFACTS
-      - run: *SUBMIT_COVERAGE
-
-  nixos-19.09:
     docker:
       # Run in a highly Nix-capable environment.
-      - image: "nixorg/nix:circleci"
+      - <<: *DOCKERHUB_AUTH
+        image: "nixorg/nix:circleci"
 
     environment:
       NIX_PATH: "nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-19.09-small.tar.gz"
@@ -384,69 +483,35 @@ jobs:
     #
     # https://circleci.com/blog/how-to-build-a-docker-image-on-circleci-2-0/
     docker:
-      - image: "docker:17.05.0-ce-git"
+      - <<: *DOCKERHUB_AUTH
+        image: "docker:17.05.0-ce-git"
 
     environment:
-      DISTRO: "tahoelafsci/<DISTRO>:foo"
+      DISTRO: "tahoelafsci/<DISTRO>:foo-py2"
-      TAG: "tahoelafsci/distro:<TAG>"
+      TAG: "tahoelafsci/distro:<TAG>-py2"
+      PYTHON_VERSION: "tahoelafsci/distro:tag-py<PYTHON_VERSION}"
 
     steps:
       - "checkout"
       - "setup_remote_docker"
-      - run:
-          name: "Get openssl"
-          command: |
-            apk add --no-cache openssl
-      - run:
-          name: "Get Dockerhub secrets"
-          command: |
-            # If you create an encryption key like this:
-            #
-            #   openssl enc -aes-256-cbc -k secret -P -md sha256
-
-            # From the output that looks like:
-            #
-            #  salt=...
-            #  key=...
-            #  iv =...
-            #
-            # extract just the value for ``key``.
-
-            # then you can re-generate ``secret-env-cipher`` locally using the
-            # command:
-            #
-            #   openssl aes-256-cbc -e -md sha256 -in secret-env-plain -out .circleci/secret-env-cipher -pass env:KEY
-            #
-            # Make sure the key is set as the KEY environment variable in the
-            # CircleCI web interface.  You can do this by visiting
-            # <https://circleci.com/gh/tahoe-lafs/tahoe-lafs/edit#env-vars>
-            # after logging in to CircleCI with an account in the tahoe-lafs
-            # CircleCI team.
-            #
-            # Then you can recover the environment plaintext (for example, to
-            # change and re-encrypt it) like just like CircleCI recovers it
-            # here:
-            #
-            openssl aes-256-cbc -d -md sha256 -in .circleci/secret-env-cipher -pass env:KEY >> ~/.env
       - run:
           name: "Log in to Dockerhub"
           command: |
-            . ~/.env
+            docker login -u ${DOCKERHUB_USERNAME} -p ${DOCKERHUB_PASSWORD}
-            # TAHOELAFSCI_PASSWORD come from the secret env.
-            docker login -u tahoelafsci -p ${TAHOELAFSCI_PASSWORD}
       - run:
           name: "Build image"
           command: |
             docker \
                 build \
                 --build-arg TAG=${TAG} \
-                -t tahoelafsci/${DISTRO}:${TAG} \
+                --build-arg PYTHON_VERSION=${PYTHON_VERSION} \
+                -t tahoelafsci/${DISTRO}:${TAG}-py${PYTHON_VERSION} \
                 -f ~/project/.circleci/Dockerfile.${DISTRO} \
                 ~/project/
       - run:
           name: "Push image"
           command: |
-            docker push tahoelafsci/${DISTRO}:${TAG}
+            docker push tahoelafsci/${DISTRO}:${TAG}-py${PYTHON_VERSION}
 
 
   build-image-debian-8:
@@ -455,6 +520,7 @@ jobs:
     environment:
       DISTRO: "debian"
       TAG: "8"
+      PYTHON_VERSION: "2.7"
 
 
   build-image-debian-9:
@@ -463,30 +529,52 @@ jobs:
     environment:
       DISTRO: "debian"
       TAG: "9"
+      PYTHON_VERSION: "2.7"
 
 
-  build-image-ubuntu-16.04:
+  build-image-ubuntu-16-04:
     <<: *BUILD_IMAGE
 
     environment:
       DISTRO: "ubuntu"
       TAG: "16.04"
+      PYTHON_VERSION: "2.7"
 
 
-  build-image-ubuntu-18.04:
+  build-image-ubuntu-18-04:
     <<: *BUILD_IMAGE
 
     environment:
       DISTRO: "ubuntu"
       TAG: "18.04"
+      PYTHON_VERSION: "2.7"
 
 
-  build-image-centos-7:
+  build-image-python36-ubuntu:
+    <<: *BUILD_IMAGE
+
+    environment:
+      DISTRO: "ubuntu"
+      TAG: "18.04"
+      PYTHON_VERSION: "3"
+
+
+  build-image-ubuntu-20-04:
+    <<: *BUILD_IMAGE
+
+    environment:
+      DISTRO: "ubuntu"
+      TAG: "20.04"
+      PYTHON_VERSION: "2.7"
+
+
+  build-image-centos-8:
     <<: *BUILD_IMAGE
 
     environment:
       DISTRO: "centos"
-      TAG: "7"
+      TAG: "8"
+      PYTHON_VERSION: "2"
 
 
   build-image-fedora-28:
@@ -495,6 +583,8 @@ jobs:
     environment:
       DISTRO: "fedora"
       TAG: "28"
+      # The default on Fedora (this version anyway) is still Python 2.
+      PYTHON_VERSION: ""
 
 
   build-image-fedora-29:
@@ -505,17 +595,13 @@ jobs:
       TAG: "29"
 
 
-  build-image-slackware-14.2:
+  build-image-pypy27-buster:
-    <<: *BUILD_IMAGE
-
-    environment:
-      DISTRO: "slackware"
-      TAG: "14.2"
-
-
-  build-image-pypy-2.7-7.1.1-jessie:
     <<: *BUILD_IMAGE
 
     environment:
       DISTRO: "pypy"
-      TAG: "2.7-7.1.1-jessie"
+      TAG: "buster"
+      # We only have Python 2 for PyPy right now so there's no support for
+      # setting up PyPy 3 in the image building toolchain.  This value is just
+      # for constructing the right Docker image tag.
+      PYTHON_VERSION: "2"

.circleci/populate-wheelhouse.sh

@@ -36,8 +36,9 @@ PIP="${BOOTSTRAP_VENV}/bin/pip"
 # Tell pip where it can find any existing wheels.
 export PIP_FIND_LINKS="file://${WHEELHOUSE_PATH}"
 
-# Populate the wheelhouse, if necessary.
+# Populate the wheelhouse, if necessary.  zfec 1.5.3 can only be built with a
-"${PIP}" \
+# UTF-8 environment so make sure we have one, at least for this invocation.
+LANG="en_US.UTF-8" "${PIP}" \
     wheel \
     --wheel-dir "${WHEELHOUSE_PATH}" \
     "${PROJECT_ROOT}"[test] \

.circleci/run-tests.sh

@@ -65,9 +65,13 @@ TIMEOUT="timeout --kill-after 1m 15m"
 # Send the output directly to a file because transporting the binary subunit2
 # via tox and then scraping it out is hideous and failure prone.
 export SUBUNITREPORTER_OUTPUT_PATH="${SUBUNIT2}"
-export TAHOE_LAFS_TRIAL_ARGS="--reporter=subunitv2-file --rterrors"
+export TAHOE_LAFS_TRIAL_ARGS="${TAHOE_LAFS_TRIAL_ARGS:---reporter=subunitv2-file --rterrors}"
 export PIP_NO_INDEX="1"
 
+# Make output unbuffered, so progress reports from subunitv2-file get streamed
+# and notify CircleCI we're still alive.
+export PYTHONUNBUFFERED=1
+
 if [ "${ALLOWED_FAILURE}" = "yes" ]; then
     alternative="true"
 else
@@ -81,7 +85,12 @@ ${TIMEOUT} ${BOOTSTRAP_VENV}/bin/tox \
     ${TAHOE_LAFS_TOX_ARGS} || "${alternative}"
 
 if [ -n "${ARTIFACTS}" ]; then
+    if [ ! -e "${SUBUNIT2}" ]; then
+	echo "subunitv2 output file does not exist: ${SUBUNIT2}"
+	exit 1
+    fi
+
     # Create a junitxml results area.
     mkdir -p "$(dirname "${JUNITXML}")"
-    ${BOOTSTRAP_VENV}/bin/subunit2junitxml < "${SUBUNIT2}" > "${JUNITXML}" || "${alternative}"
+    "${BOOTSTRAP_VENV}"/bin/subunit2junitxml < "${SUBUNIT2}" > "${JUNITXML}" || "${alternative}"
 fi

.circleci/secret-env-cipher

@@ -1 +0,0 @@
-Salted__ •GPÁøÊ)|!÷[©U[‡ûvSÚ,F¿–m:ö š~ÓY[Uú_¸Fx×’¤Ÿ%<25>“4l×Ö»Š8¼œ¹„1öø‰/lƒÌ`nÆ^·Z]óqš¬æ¢&ø°÷£Ý‚‚ß%T¡n

.codecov.yml

@@ -0,0 +1,34 @@
+# Override defaults for codecov.io checks.
+#
+# Documentation is at https://docs.codecov.io/docs/codecov-yaml;
+# reference is at https://docs.codecov.io/docs/codecovyml-reference.
+#
+# To validate this file, use:
+#
+#   curl --data-binary @.codecov.yml https://codecov.io/validate
+#
+# Codecov's defaults seem to leave red marks in GitHub CI checks in a
+# rather arbitrary manner, probably because of non-determinism in
+# coverage (see https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2891)
+# and maybe because computers are bad with floating point numbers.
+
+# Allow coverage percentage a precision of zero decimals, and round to
+# the nearest number (for example, 89.957 to to 90; 89.497 to 89%).
+# Coverage above 90% is good, below 80% is bad.
+coverage:
+  round: nearest
+  range: 80..90
+  precision: 0
+
+  # Aim for a target test coverage of 90% in codecov/project check (do
+  # not allow project coverage to drop below that), and allow
+  # codecov/patch a threshold of 1% (allow coverage in changes to drop
+  # by that much, and no less).  That should be good enough for us.
+  status:
+    project:
+      default:
+        target: 90%
+        threshold: 1%
+    patch:
+      default:
+        threshold: 1%

.coveragerc

@@ -10,3 +10,18 @@ omit =
      */allmydata/_version.py
 parallel = True
 branch = True
+
+[report]
+show_missing = True
+skip_covered = True
+
+[paths]
+source =
+# It looks like this in the checkout
+    src/
+# It looks like this in the Windows build environment
+    D:/a/tahoe-lafs/tahoe-lafs/.tox/py*-coverage/Lib/site-packages/
+# Although sometimes it looks like this instead.  Also it looks like this on macOS.
+    .tox/py*-coverage/lib/python*/site-packages/
+# On some Linux CI jobs it looks like this
+    /tmp/tahoe-lafs.tox/py*-coverage/lib/python*/site-packages/

.github/workflows/ci.yml

@@ -0,0 +1,183 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - "master"
+  pull_request:
+
+jobs:
+
+  coverage:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-latest
+          - windows-latest
+        python-version:
+          - 2.7
+
+    steps:
+
+      # Get vcpython27 on Windows + Python 2.7, to build zfec
+      # extension.  See https://chocolatey.org/packages/vcpython27 and
+      # https://github.com/crazy-max/ghaction-chocolatey
+      - name: Install MSVC 9.0 for Python 2.7 [Windows]
+        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install vcpython27
+
+      - name: Check out Tahoe-LAFS sources
+        uses: actions/checkout@v2
+
+      - name: Fetch all history for all tags and branches
+        run: git fetch --prune --unshallow
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Python packages
+        run: |
+          pip install --upgrade codecov tox setuptools
+          pip list
+
+      - name: Display tool versions
+        run: python misc/build_helpers/show-tool-versions.py
+
+      - name: Run "tox -e py27-coverage"
+        run: tox -e py27-coverage
+
+      - name: Upload eliot.log in case of failure
+        uses: actions/upload-artifact@v1
+        if: failure()
+        with:
+          name: eliot.log
+          path: eliot.log
+
+      - name: Upload coverage report
+        uses: codecov/codecov-action@v1
+        with:
+          token: abf679b6-e2e6-4b33-b7b5-6cfbd41ee691
+          file: coverage.xml
+
+  integration:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-latest
+          - windows-latest
+        python-version:
+          - 2.7
+
+    steps:
+
+      - name: Install Tor [Ubuntu]
+        if: matrix.os == 'ubuntu-latest'
+        run: sudo apt install tor
+
+      - name: Install Tor [macOS]
+        if: matrix.os == 'macos-latest'
+        run: brew install tor
+
+      - name: Install Tor [Windows]
+        if: matrix.os == 'windows-latest'
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install tor
+
+      - name: Install MSVC 9.0 for Python 2.7 [Windows]
+        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install vcpython27
+
+      - name: Check out Tahoe-LAFS sources
+        uses: actions/checkout@v2
+
+      - name: Fetch all history for all tags and branches
+        run: git fetch --prune --unshallow
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Python packages
+        run: |
+          pip install --upgrade tox
+          pip list
+
+      - name: Display tool versions
+        run: python misc/build_helpers/show-tool-versions.py
+
+      - name: Run "tox -e integration"
+        run: tox -e integration
+
+      - name: Upload eliot.log in case of failure
+        uses: actions/upload-artifact@v1
+        if: failure()
+        with:
+          name: integration.eliot.json
+          path: integration.eliot.json
+
+  packaging:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-latest
+          - windows-latest
+          - ubuntu-latest
+        python-version:
+          - 2.7
+
+    steps:
+
+      # Get vcpython27 on Windows + Python 2.7, to build zfec
+      # extension.  See https://chocolatey.org/packages/vcpython27 and
+      # https://github.com/crazy-max/ghaction-chocolatey
+      - name: Install MSVC 9.0 for Python 2.7 [Windows]
+        if: matrix.os == 'windows-latest' && matrix.python-version == '2.7'
+        uses: crazy-max/ghaction-chocolatey@v1
+        with:
+          args: install vcpython27
+
+      - name: Check out Tahoe-LAFS sources
+        uses: actions/checkout@v2
+
+      - name: Fetch all history for all tags and branches
+        run: git fetch --prune --unshallow
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v1
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Python packages
+        run: |
+          pip install --upgrade tox
+          pip list
+
+      - name: Display tool versions
+        run: python misc/build_helpers/show-tool-versions.py
+
+      - name: Run "tox -e pyinstaller"
+        run: tox -e pyinstaller
+
+      # This step is to ensure there are no packaging/import errors.
+      - name: Test PyInstaller executable
+        run: dist/Tahoe-LAFS/tahoe --version
+
+      - name: Upload PyInstaller package
+        uses: actions/upload-artifact@v2
+        with:
+          name: Tahoe-LAFS-${{ matrix.os }}-Python-${{ matrix.python-version }}
+          path: dist/Tahoe-LAFS-*-*.*

.gitignore

@@ -1,4 +1,4 @@
-venv
+venv*
 
 # vim swap files
 *.swp
@@ -9,6 +9,7 @@ venv
 *~
 *.DS_Store
 .*.kate-swp
+*.bak
 
 /build/
 /support/
@@ -36,6 +37,7 @@ zope.interface-*.egg
 /tahoe-deps/
 /tahoe-deps.tar.gz
 /.coverage
+/.coverage.*
 /.coverage.el
 /coverage-html/
 /miscaptures.txt
@@ -43,8 +45,11 @@ zope.interface-*.egg
 /.tox/
 /docs/_build/
 /coverage.xml
-/smoke_magicfolder/
+/.pre-commit-config.local.yaml
 /.hypothesis/
+/eliot.log
+/misc/python3/results.xml
+/misc/python3/results.subunit2
 
 # This is the plaintext of the private environment needed for some CircleCI
 # operations.  It's never supposed to be checked in.

.pre-commit-config.yaml

@@ -0,0 +1,9 @@
+repos:
+  - repo: local
+    hooks:
+    - id: codechecks
+      name: codechecks
+      stages: ["push"]
+      entry: "tox -e codechecks"
+      language: system
+      pass_filenames: false

.travis.yml

@@ -1,77 +0,0 @@
-sudo: false
-language: python
-cache: pip
-dist: trusty
-before_cache:
-  - rm -f $HOME/.cache/pip/log/debug.log
-git:
-  depth: 1000
-
-env:
-  global:
-    - TAHOE_LAFS_HYPOTHESIS_PROFILE=ci
-
-install:
-# ~/.local/bin is on $PATH by default, but on OS-X, --user puts it elsewhere
-  - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then export PATH=$HOME/Library/Python/2.7/bin:$PATH; fi
-  - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then wget https://bootstrap.pypa.io/get-pip.py && sudo python ./get-pip.py; fi
-  - pip list
-  - if [ "${TRAVIS_OS_NAME}" = "osx" ]; then pip install --user --upgrade codecov tox setuptools; fi
-  - if [ "${TRAVIS_OS_NAME}" = "linux" ]; then pip install --upgrade codecov tox setuptools; fi
-  - echo $PATH; which python; which pip; which tox
-  - python misc/build_helpers/show-tool-versions.py
-
-script:
-  - |
-    set -eo pipefail
-    if [ "${T}" = "py35" ]; then
-      python3 -m compileall -f -x tahoe-depgraph.py .
-    else
-      tox -e ${T}
-    fi
-    # To verify that the resultant PyInstaller-generated binary executes
-    # cleanly (i.e., that it terminates with an exit code of 0 and isn't
-    # failing due to import/packaging-related errors, etc.).
-    if [ "${T}" = "pyinstaller" ]; then dist/Tahoe-LAFS/tahoe --version; fi
-
-after_success:
-  - if [ "${T}" = "coverage" ]; then codecov; fi
-
-notifications:
-  email: false
-  irc:
-    channels: "chat.freenode.net#tahoe-lafs"
-    on_success: always # for testing
-    on_failure: always
-    template:
-      - "%{repository}#%{build_number} [%{branch}: %{commit} by %{author}] %{message}"
-      - "Changes: %{compare_url} | Details: %{build_url}"
-
-matrix:
-  include:
-  - os: linux
-    python: '2.7'
-    env: T=coverage LANG=en_US.UTF-8
-  - os: linux
-    python: '2.7'
-    env: T=codechecks LANG=en_US.UTF-8
-  - os: linux
-    python: '2.7'
-    env: T=pyinstaller LANG=en_US.UTF-8
-  - os: linux
-    python: '2.7'
-    env: T=py27 LANG=C
-  - os: osx
-    python: '2.7'
-    env: T=py27 LANG=en_US.UTF-8
-    language: generic  # "python" is not available on OS-X
-  - os: osx
-    python: '2.7'
-    env: T=pyinstaller LANG=en_US.UTF-8
-    language: generic  # "python" is not available on OS-X
-  # this is a "lint" job that checks for python3 compatibility
-  - os: linux
-    python: '3.5'
-    env: T=py35
-
-  fast_finish: true

Makefile

@@ -1,16 +1,68 @@
-
+# Tahoe LFS Development and maintenance tasks
+#
 # NOTE: this Makefile requires GNU make
 
+### Defensive settings for make:
+#     https://tech.davis-hansson.com/p/make/
+SHELL := bash
+.ONESHELL:
+.SHELLFLAGS := -xeu -o pipefail -c
+.SILENT:
+.DELETE_ON_ERROR:
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rules
+
+# Local target variables
+VCS_HOOK_SAMPLES=$(wildcard .git/hooks/*.sample)
+VCS_HOOKS=$(VCS_HOOK_SAMPLES:%.sample=%)
+PYTHON=python
+export PYTHON
+PYFLAKES=flake8
+export PYFLAKES
+VIRTUAL_ENV=./.tox/py27
+SOURCES=src/allmydata static misc setup.py
+APPNAME=tahoe-lafs
+TEST_SUITE=allmydata
+
+
+# Top-level, phony targets
+
+.PHONY: default
 default:
 	@echo "no default target"
 
-PYTHON=python
+.PHONY: install-vcs-hooks
-export PYTHON
+## Install the VCS hooks to run linters on commit and all tests on push
-PYFLAKES=pyflakes
+install-vcs-hooks: .git/hooks/pre-commit .git/hooks/pre-push
-export PYFLAKES
+.PHONY: uninstall-vcs-hooks
+## Remove the VCS hooks
+uninstall-vcs-hooks: .tox/create-venvs.log
+	"./$(dir $(<))py36/bin/pre-commit" uninstall || true
+	"./$(dir $(<))py36/bin/pre-commit" uninstall -t pre-push || true
 
-SOURCES=src/allmydata static misc setup.py
+.PHONY: test
-APPNAME=tahoe-lafs
+## Run all tests and code reports
+test: .tox/create-venvs.log
+# Run codechecks first since it takes the least time to report issues early.
+	tox --develop -e codechecks
+# Run all the test environments in parallel to reduce run-time
+	tox --develop -p auto -e 'py27,py36,pypy27'
+.PHONY: test-venv-coverage
+## Run all tests with coverage collection and reporting.
+test-venv-coverage:
+# Special handling for reporting coverage even when the test run fails
+	rm -f ./.coverage.*
+	test_exit=
+	$(VIRTUAL_ENV)/bin/coverage run -m twisted.trial --rterrors --reporter=timing \
+		$(TEST_SUITE) || test_exit="$$?"
+	$(VIRTUAL_ENV)/bin/coverage combine
+	$(VIRTUAL_ENV)/bin/coverage xml || true
+	$(VIRTUAL_ENV)/bin/coverage report
+	if [ ! -z "$$test_exit" ]; then exit "$$test_exit"; fi
+.PHONY: test-py3-all
+## Run all tests under Python 3
+test-py3-all: .tox/create-venvs.log
+	tox --develop -e py36 allmydata
 
 # This is necessary only if you want to automatically produce a new
 # _version.py file from the current git history (without doing a build).
@@ -18,20 +70,16 @@ APPNAME=tahoe-lafs
 make-version:
 	$(PYTHON) ./setup.py update_version
 
-.built:
-	$(MAKE) build
-
-src/allmydata/_version.py:
-	$(MAKE) make-version
-
 # Build OS X pkg packages.
-.PHONY: build-osx-pkg test-osx-pkg upload-osx-pkg
+.PHONY: build-osx-pkg
 build-osx-pkg:
 	misc/build_helpers/build-osx-pkg.sh $(APPNAME)
 
+.PHONY: test-osx-pkg
 test-osx-pkg:
 	$(PYTHON) misc/build_helpers/test-osx-pkg.py
 
+.PHONY: upload-osx-pkg
 upload-osx-pkg:
 	# [Failure instance: Traceback: <class 'OpenSSL.SSL.Error'>: [('SSL routines', 'ssl3_read_bytes', 'tlsv1 alert unknown ca'), ('SSL routines', 'ssl3_write_bytes', 'ssl handshake failure')]
 	#
@@ -42,35 +90,12 @@ upload-osx-pkg:
 	#   echo not uploading tahoe-lafs-osx-pkg because this is not trunk but is branch \"${BB_BRANCH}\" ; \
 	# fi
 
-.PHONY: smoketest
-smoketest:
-	-python ./src/allmydata/test/check_magicfolder_smoke.py kill
-	-rm -rf smoke_magicfolder/
-	python ./src/allmydata/test/check_magicfolder_smoke.py
-
-# code coverage-based testing is disabled temporarily, as we switch to tox.
-# This will eventually be added to a tox environment. The following comments
-# and variable settings are retained as notes for that future effort.
-
-## # code coverage: install the "coverage" package from PyPI, do "make
-## # test-coverage" to do a unit test run with coverage-gathering enabled, then
-## # use "make coverage-output" to generate an HTML report. Also see "make
-## # .coverage.el" and misc/coding_tools/coverage.el for Emacs integration.
-##
-## # This might need to be python-coverage on Debian-based distros.
-## COVERAGE=coverage
-##
-## COVERAGEARGS=--branch --source=src/allmydata
-##
-## # --include appeared in coverage-3.4
-## COVERAGE_OMIT=--include '$(CURDIR)/src/allmydata/*' --omit '$(CURDIR)/src/allmydata/test/*'
-
-
 .PHONY: code-checks
 #code-checks: build version-and-path check-interfaces check-miscaptures -find-trailing-spaces -check-umids pyflakes
 code-checks: check-interfaces check-debugging check-miscaptures -find-trailing-spaces -check-umids pyflakes
 
 .PHONY: check-interfaces
+check-interfaces:
 	$(PYTHON) misc/coding_tools/check-interfaces.py 2>&1 |tee violations.txt
 	@echo
 
@@ -190,10 +215,11 @@ clean:
 	rm -f *.pkg
 
 .PHONY: distclean
-distclean: clean
+distclean: clean uninstall-vcs-hooks
 	rm -rf src/*.egg-info
 	rm -f src/allmydata/_version.py
 	rm -f src/allmydata/_appname.py
+	rm -rf ./.tox/
 
 
 .PHONY: find-trailing-spaces
@@ -226,3 +252,15 @@ tarballs: # delegated to tox, so setup.py can update setuptools if needed
 .PHONY: upload-tarballs
 upload-tarballs:
 	@if [ "X${BB_BRANCH}" = "Xmaster" ] || [ "X${BB_BRANCH}" = "X" ]; then for f in dist/*; do flappclient --furlfile ~/.tahoe-tarball-upload.furl upload-file $$f; done ; else echo not uploading tarballs because this is not trunk but is branch \"${BB_BRANCH}\" ; fi
+
+
+# Real targets
+
+src/allmydata/_version.py:
+	$(MAKE) make-version
+
+.tox/create-venvs.log: tox.ini setup.py
+	tox --notest -p all | tee -a "$(@)"
+
+$(VCS_HOOKS): .tox/create-venvs.log .pre-commit-config.yaml
+	"./$(dir $(<))py36/bin/pre-commit" install --hook-type $(@:.git/hooks/%=%)

NEWS.rst

@@ -5,6 +5,115 @@ User-Visible Changes in Tahoe-LAFS
 ==================================
 
 .. towncrier start line
+Release 1.14.0 (2020-03-11)
+'''''''''''''''''''''''''''
+
+Features
+--------
+
+- Magic-Folders are now supported on macOS. (`#1432 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1432>`_)
+- Add a "tox -e draftnews" which runs towncrier in draft mode (`#2942 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2942>`_)
+- Fedora 29 is now tested as part of the project's continuous integration system. (`#2955 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2955>`_)
+- The Magic-Folder frontend now emits structured, causal logs.  This makes it easier for developers to make sense of its behavior and for users to submit useful debugging information alongside problem reports. (`#2972 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2972>`_)
+- The `tahoe` CLI now accepts arguments for configuring structured logging messages which Tahoe-LAFS is being converted to emit.  This change does not introduce any new defaults for on-filesystem logging. (`#2975 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2975>`_)
+- The web API now publishes streaming Eliot logs via a token-protected WebSocket at /private/logs/v1. (`#3006 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3006>`_)
+- End-to-end in-memory tests for websocket features (`#3041 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3041>`_)
+- allmydata.interfaces.IFoolscapStoragePlugin has been introduced, an extension point for customizing the storage protocol. (`#3049 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3049>`_)
+- Static storage server "announcements" in ``private/servers.yaml`` are now individually logged and ignored if they cannot be interpreted. (`#3051 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3051>`_)
+- Storage servers can now be configured to load plugins for allmydata.interfaces.IFoolscapStoragePlugin and offer them to clients. (`#3053 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3053>`_)
+- Storage clients can now be configured to load plugins for allmydata.interfaces.IFoolscapStoragePlugin and use them to negotiate with servers. (`#3054 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3054>`_)
+- The [storage] configuration section now accepts a boolean *anonymous* item to enable or disable anonymous storage access.  The default behavior remains unchanged. (`#3184 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3184>`_)
+- Enable the helper when creating a node with `tahoe create-node --helper` (`#3235 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3235>`_)
+
+
+Bug Fixes
+---------
+
+- refactor initialization code to be more async-friendly (`#2870 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2870>`_)
+- Configuration-checking code wasn't being called due to indenting (`#2935 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2935>`_)
+- refactor configuration handling out of Node into _Config (`#2936 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2936>`_)
+- "tox -e codechecks" no longer dirties the working tree. (`#2941 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2941>`_)
+- Updated the Tor release key, used by the integration tests. (`#2944 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2944>`_)
+- `tahoe backup` no longer fails with an unhandled exception when it encounters a special file (device, fifo) in the backup source. (`#2950 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2950>`_)
+- Magic-Folders now creates spurious conflict files in fewer cases.  In particular, if files are added to the folder while a client is offline, that client will not create conflict files for all those new files when it starts up. (`#2965 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2965>`_)
+- The confusing and misplaced sub-command group headings in `tahoe --help` output have been removed. (`#2976 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2976>`_)
+- The Magic-Folder frontend is now more responsive to subtree changes on Windows. (`#2997 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2997>`_)
+- remove ancient bundled jquery and d3, and the "dowload timeline" feature they support (`#3228 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3228>`_)
+
+
+Dependency/Installation Changes
+-------------------------------
+
+- Tahoe-LAFS no longer makes start-up time assertions about the versions of its dependencies.  It is the responsibility of the administrator of the installation to ensure the correct version of dependencies are supplied. (`#2749 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2749>`_)
+- Tahoe-LAFS now depends on Twisted 16.6 or newer. (`#2957 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2957>`_)
+
+
+Removed Features
+----------------
+
+- "tahoe rm", an old alias for "tahoe unlink", has been removed. (`#1827 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1827>`_)
+- The direct dependencies on pyutil and zbase32 have been removed. (`#2098 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2098>`_)
+- Untested and unmaintained code for running Tahoe-LAFS as a Windows service has been removed. (`#2239 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2239>`_)
+- The redundant "pypywin32" dependency has been removed. (`#2392 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2392>`_)
+- Fedora 27 is no longer tested as part of the project's continuous integration system. (`#2955 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2955>`_)
+- "tahoe start", "tahoe daemonize", "tahoe restart", and "tahoe stop" are now deprecated in favor of using "tahoe run", possibly with a third-party process manager. (`#3273 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3273>`_)
+
+
+Other Changes
+-------------
+
+- Tahoe-LAFS now tests for PyPy compatibility on CI. (`#2479 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2479>`_)
+- Tahoe-LAFS now requires Twisted 18.4.0 or newer. (`#2771 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2771>`_)
+- Tahoe-LAFS now uses towncrier to maintain the NEWS file. (`#2908 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2908>`_)
+- The release process document has been updated. (`#2920 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2920>`_)
+- allmydata.test.test_system.SystemTest is now more reliable with respect to bound address collisions. (`#2933 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2933>`_)
+- The Tox configuration has been fixed to work around a problem on Windows CI. (`#2956 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2956>`_)
+- The PyInstaller CI job now works around a pip/pyinstaller incompatibility. (`#2958 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2958>`_)
+- Some CI jobs for integration tests have been moved from TravisCI to CircleCI. (`#2959 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2959>`_)
+- Several warnings from a new release of pyflakes have been fixed. (`#2960 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2960>`_)
+- Some Slackware 14.2 continuous integration problems have been resolved. (`#2961 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2961>`_)
+- Some macOS continuous integration failures have been fixed. (`#2962 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2962>`_)
+- The NoNetworkGrid implementation has been somewhat improved. (`#2966 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2966>`_)
+- A bug in the test suite for the create-alias command has been fixed. (`#2967 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2967>`_)
+- The integration test suite has been updated to use pytest-twisted instead of deprecated pytest APIs. (`#2968 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2968>`_)
+- The magic-folder integration test suite now performs more aggressive cleanup of the processes it launches. (`#2969 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2969>`_)
+- The integration tests now correctly document the `--keep-tempdir` option. (`#2970 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2970>`_)
+- A misuse of super() in the integration tests has been fixed. (`#2971 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2971>`_)
+- Several utilities to facilitate the use of the Eliot causal logging library have been introduced. (`#2973 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2973>`_)
+- The Windows CI configuration has been tweaked. (`#2974 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2974>`_)
+- The Magic-Folder frontend has had additional logging improvements. (`#2977 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2977>`_)
+-  (`#2981 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2981>`_, `#2982 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2982>`_)
+- Added a simple sytax checker so that once a file has reached python3 compatibility, it will not regress. (`#3001 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3001>`_)
+- Converted all uses of the print statement to the print function in the ./misc/ directory. (`#3002 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3002>`_)
+- The contributor guidelines are now linked from the GitHub pull request creation page. (`#3003 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3003>`_)
+- Updated the testing code to use the print function instead of the print statement. (`#3008 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3008>`_)
+- Replaced print statement with print fuction for all tahoe_* scripts. (`#3009 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3009>`_)
+- Replaced all remaining instances of the print statement with the print function. (`#3010 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3010>`_)
+- Replace StringIO imports with six.moves. (`#3011 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3011>`_)
+- Updated all Python files to use PEP-3110 exception syntax for Python3 compatibility. (`#3013 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3013>`_)
+- Update raise syntax for Python3 compatibility. (`#3014 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3014>`_)
+- Updated instances of octal literals to use the format 0o123 for Python3 compatibility. (`#3015 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3015>`_)
+- allmydata.test.no_network, allmydata.test.test_system, and allmydata.test.web.test_introducer are now more reliable with respect to bound address collisions. (`#3016 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3016>`_)
+- Removed tuple unpacking from function and lambda definitions for Python3 compatibility. (`#3019 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3019>`_)
+- Updated Python2 long numeric literals for Python3 compatibility. (`#3020 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3020>`_)
+- CircleCI jobs are now faster as a result of pre-building configured Docker images for the CI jobs. (`#3024 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3024>`_)
+- Removed used of backticks for "repr" for Python3 compatibility. (`#3027 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3027>`_)
+- Updated string literal syntax for Python3 compatibility. (`#3028 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3028>`_)
+- Updated CI to enforce Python3 syntax for entire repo. (`#3030 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3030>`_)
+- Replaced pycryptopp with cryptography. (`#3031 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3031>`_)
+- All old-style classes ported to new-style. (`#3042 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3042>`_)
+- Whitelisted "/bin/mv" as command for codechecks performed by tox. This fixes a current warning and prevents future errors (for tox 4). (`#3043 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3043>`_)
+- Progress towards Python 3 compatibility is now visible at <https://tahoe-lafs.github.io/tahoe-depgraph/>. (`#3152 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3152>`_)
+- Collect coverage information from integration tests (`#3234 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3234>`_)
+- NixOS is now a supported Tahoe-LAFS platform. (`#3266 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3266>`_)
+
+
+Misc/Other
+----------
+
+- `#1893 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1893>`_, `#2266 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2266>`_, `#2283 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2283>`_, `#2766 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2766>`_, `#2980 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2980>`_, `#2985 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2985>`_, `#2986 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2986>`_, `#2987 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2987>`_, `#2988 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2988>`_, `#2989 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2989>`_, `#2990 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2990>`_, `#2991 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2991>`_, `#2992 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2992>`_, `#2995 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2995>`_, `#3000 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3000>`_, `#3004 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3004>`_, `#3005 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3005>`_, `#3007 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3007>`_, `#3012 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3012>`_, `#3017 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3017>`_, `#3021 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3021>`_, `#3023 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3023>`_, `#3025 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3025>`_, `#3026 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3026>`_, `#3029 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3029>`_, `#3036 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3036>`_, `#3038 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3038>`_, `#3048 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3048>`_, `#3086 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3086>`_, `#3097 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3097>`_, `#3111 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3111>`_, `#3118 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3118>`_, `#3119 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3119>`_, `#3227 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3227>`_, `#3229 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3229>`_, `#3232 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3232>`_, `#3233 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3233>`_, `#3237 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3237>`_, `#3238 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3238>`_, `#3239 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3239>`_, `#3240 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3240>`_, `#3242 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3242>`_, `#3243 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3243>`_, `#3245 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3245>`_, `#3246 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3246>`_, `#3248 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3248>`_, `#3250 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3250>`_, `#3252 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3252>`_, `#3255 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3255>`_, `#3256 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3256>`_, `#3259 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3259>`_, `#3261 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3261>`_, `#3262 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3262>`_, `#3263 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3263>`_, `#3264 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3264>`_, `#3265 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3265>`_, `#3267 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3267>`_, `#3268 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3268>`_, `#3271 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3271>`_, `#3272 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3272>`_, `#3274 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3274>`_, `#3275 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3275>`_, `#3276 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3276>`_, `#3279 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3279>`_, `#3281 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3281>`_, `#3282 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3282>`_, `#3285 <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3285>`_
+
+
 Release 1.13.0 (05-August-2018)
 '''''''''''''''''''''''''''''''
 

README.rst

@@ -10,7 +10,8 @@ function correctly, preserving your privacy and security.
 For full documentation, please see
 http://tahoe-lafs.readthedocs.io/en/latest/ .
 
-|readthedocs|  |travis|  |circleci|  |codecov|
+|Contributor Covenant|  |readthedocs|  |travis|  |circleci|  |codecov|
+
 
 INSTALLING
 ==========
@@ -105,3 +106,7 @@ slides.
 .. |codecov| image:: https://codecov.io/github/tahoe-lafs/tahoe-lafs/coverage.svg?branch=master
     :alt: test coverage percentage
     :target: https://codecov.io/github/tahoe-lafs/tahoe-lafs?branch=master
+
+.. |Contributor Covenant| image:: https://img.shields.io/badge/Contributor%20Covenant-v2.0%20adopted-ff69b4.svg
+    :alt: code of conduct
+    :target: docs/CODE_OF_CONDUCT.md

docs/CODE_OF_CONDUCT.md

@@ -0,0 +1,54 @@
+# Contributor Code of Conduct
+
+As contributors and maintainers of this project, and in the interest of
+fostering an open and welcoming community, we pledge to respect all people who
+contribute through reporting issues, posting feature requests, updating
+documentation, submitting pull requests or patches, and other activities.
+
+We are committed to making participation in this project a harassment-free
+experience for everyone, regardless of level of experience, gender, gender
+identity and expression, sexual orientation, disability, personal appearance,
+body size, race, ethnicity, age, religion, or nationality.
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery
+* Personal attacks
+* Trolling or insulting/derogatory comments
+* Public or private harassment
+* Publishing other's private information, such as physical or electronic
+  addresses, without explicit permission
+* Other unethical or unprofessional conduct
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+By adopting this Code of Conduct, project maintainers commit themselves to
+fairly and consistently applying these principles to every aspect of managing
+this project. Project maintainers who do not follow or enforce the Code of
+Conduct may be permanently removed from the project team.
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community.
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting a project maintainer (see below). All
+complaints will be reviewed and investigated and will result in a response that
+is deemed necessary and appropriate to the circumstances. Maintainers are
+obligated to maintain confidentiality with regard to the reporter of an
+incident.
+
+The following community members have made themselves available for conduct issues:
+
+- Jean-Paul Calderone (jean-paul at leastauthority dot com)
+- meejah (meejah at meejah dot ca)
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 1.3.0, available at
+[http://contributor-covenant.org/version/1/3/0/][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/3/0/

docs/INSTALL.rst

@@ -163,7 +163,7 @@ from PyPI with ``venv/bin/pip install tahoe-lafs``. After installation, run
  Successfully installed ...
  
  % venv/bin/tahoe --version
- tahoe-lafs: 1.13.0
+ tahoe-lafs: 1.14.0
  foolscap: ...
  
  %
@@ -183,14 +183,14 @@ You can also install directly from the source tarball URL::
  New python executable in ~/venv/bin/python2.7
  Installing setuptools, pip, wheel...done.
  
- % venv/bin/pip install https://tahoe-lafs.org/downloads/tahoe-lafs-1.13.0.tar.bz2
+ % venv/bin/pip install https://tahoe-lafs.org/downloads/tahoe-lafs-1.14.0.tar.bz2
- Collecting https://tahoe-lafs.org/downloads/tahoe-lafs-1.13.0.tar.bz2
+ Collecting https://tahoe-lafs.org/downloads/tahoe-lafs-1.14.0.tar.bz2
  ...
  Installing collected packages: ...
  Successfully installed ...
  
  % venv/bin/tahoe --version
- tahoe-lafs: 1.13.0
+ tahoe-lafs: 1.14.0
  ...
 
 Extras
@@ -224,7 +224,7 @@ the additional libraries needed to run the unit tests::
  Successfully installed ...
  
  % venv/bin/tahoe --version
- tahoe-lafs: 1.13.0.post34.dev0
+ tahoe-lafs: 1.14.0.post34.dev0
  ...
 
 This way, you won't have to re-run the ``pip install`` step each time you
@@ -273,7 +273,7 @@ result in a "all tests passed" mesage::
  % tox
  GLOB sdist-make: ~/tahoe-lafs/setup.py
  py27 recreate: ~/tahoe-lafs/.tox/py27
- py27 inst: ~/tahoe-lafs/.tox/dist/tahoe-lafs-1.13.0.post8.dev0.zip
+ py27 inst: ~/tahoe-lafs/.tox/dist/tahoe-lafs-1.14.0.post8.dev0.zip
  py27 runtests: commands[0] | tahoe --version
  py27 runtests: commands[1] | trial --rterrors allmydata
  allmydata.test.test_auth

docs/configuration.rst

@@ -82,7 +82,6 @@ Client/server nodes provide one or more of the following services:
 * web-API service
 * SFTP service
 * FTP service
-* Magic Folder service
 * helper service
 * storage service.
 
@@ -719,12 +718,6 @@ SFTP, FTP
     for instructions on configuring these services, and the ``[sftpd]`` and
     ``[ftpd]`` sections of ``tahoe.cfg``.
 
-Magic Folder
-
-    A node running on Linux or Windows can be configured to automatically
-    upload files that are created or changed in a specified local directory.
-    See :doc:`frontends/magic-folder` for details.
-
 
 Storage Server Configuration
 ============================

docs/developer-guide.rst

@@ -0,0 +1,89 @@
+Developer Guide
+===============
+
+
+Pre-commit Checks
+-----------------
+
+This project is configured for use with `pre-commit`_ to install `VCS/git hooks`_ which
+perform some static code analysis checks and other code checks to catch common errors
+before each commit and to run the full self-test suite to find less obvious regressions
+before each push to a remote.
+
+For example::
+
+  tahoe-lafs $ make install-vcs-hooks
+  ...
+  + ./.tox//py36/bin/pre-commit install --hook-type pre-commit
+  pre-commit installed at .git/hooks/pre-commit
+  + ./.tox//py36/bin/pre-commit install --hook-type pre-push
+  pre-commit installed at .git/hooks/pre-push
+  tahoe-lafs $ python -c "import pathlib; pathlib.Path('src/allmydata/tabbed.py').write_text('def foo():\\n\\tpass\\n')"
+  tahoe-lafs $ git add src/allmydata/tabbed.py
+  tahoe-lafs $ git commit -a -m "Add a file that violates flake8"
+  ...
+  codechecks...............................................................Failed
+  - hook id: codechecks
+  - exit code: 1
+
+  GLOB sdist-make: ./tahoe-lafs/setup.py
+  codechecks inst-nodeps: ...
+  codechecks installed: ...
+  codechecks run-test-pre: PYTHONHASHSEED='...'
+  codechecks run-test: commands[0] | flake8 src static misc setup.py
+  src/allmydata/tabbed.py:2:1: W191 indentation contains tabs
+  ERROR: InvocationError for command ./tahoe-lafs/.tox/codechecks/bin/flake8 src static misc setup.py (exited with code 1)
+  ___________________________________ summary ____________________________________
+  ERROR:   codechecks: commands failed
+  ...
+
+To uninstall::
+
+  tahoe-lafs $ make uninstall-vcs-hooks
+  ...
+  + ./.tox/py36/bin/pre-commit uninstall
+  pre-commit uninstalled
+  + ./.tox/py36/bin/pre-commit uninstall -t pre-push
+  pre-push uninstalled
+
+Note that running the full self-test suite takes several minutes so expect pushing to
+take some time.  If you can't or don't want to wait for the hooks in some cases, use the
+``--no-verify`` option to ``$ git commit ...`` or ``$ git push ...``.  Alternatively,
+see the `pre-commit`_ documentation and CLI help output and use the committed
+`pre-commit configuration`_ as a starting point to write a local, uncommitted
+``../.pre-commit-config.local.yaml`` configuration to use instead.  For example::
+
+  tahoe-lafs $ ./.tox/py36/bin/pre-commit --help
+  tahoe-lafs $ ./.tox/py36/bin/pre-commit instll --help
+  tahoe-lafs $ cp  "./.pre-commit-config.yaml" "./.pre-commit-config.local.yaml"
+  tahoe-lafs $ editor "./.pre-commit-config.local.yaml"
+  ...
+  tahoe-lafs $ ./.tox/py36/bin/pre-commit install -c "./.pre-commit-config.local.yaml" -t pre-push
+  pre-commit installed at .git/hooks/pre-push
+  tahoe-lafs $ git commit -a -m "Add a file that violates flake8"
+  [3398.pre-commit 29f8f43d2] Add a file that violates flake8
+   1 file changed, 2 insertions(+)
+   create mode 100644 src/allmydata/tabbed.py
+  tahoe-lafs $ git push
+  ...
+  codechecks...............................................................Failed
+  - hook id: codechecks
+  - exit code: 1
+
+  GLOB sdist-make: ./tahoe-lafs/setup.py
+  codechecks inst-nodeps: ...
+  codechecks installed: ...
+  codechecks run-test-pre: PYTHONHASHSEED='...'
+  codechecks run-test: commands[0] | flake8 src static misc setup.py
+  src/allmydata/tabbed.py:2:1: W191 indentation contains tabs
+  ERROR: InvocationError for command ./tahoe-lafs/.tox/codechecks/bin/flake8 src static misc setup.py (exited with code 1)
+  ___________________________________ summary ____________________________________
+  ERROR:   codechecks: commands failed
+  ...
+
+  error: failed to push some refs to 'github.com:jaraco/tahoe-lafs.git'
+
+
+.. _`pre-commit`: https://pre-commit.com
+.. _`VCS/git hooks`: `pre-commit`_
+.. _`pre-commit configuration`: ../.pre-commit-config.yaml

docs/frontends/magic-folder.rst

@@ -1,148 +0,0 @@
-.. -*- coding: utf-8-with-signature -*-
-
-================================
-Tahoe-LAFS Magic Folder Frontend
-================================
-
-1.  `Introduction`_
-2.  `Configuration`_
-3.  `Known Issues and Limitations With Magic-Folder`_
-
-
-Introduction
-============
-
-The Magic Folder frontend synchronizes local directories on two or more
-clients, using a Tahoe-LAFS grid for storage. Whenever a file is created
-or changed under the local directory of one of the clients, the change is
-propagated to the grid and then to the other clients.
-
-The implementation of the "drop-upload" frontend, on which Magic Folder is
-based, was written as a prototype at the First International Tahoe-LAFS
-Summit in June 2011. In 2015, with the support of a grant from the
-`Open Technology Fund`_, it was redesigned and extended to support
-synchronization between clients. It currently works on Linux and Windows.
-
-Magic Folder is not currently in as mature a state as the other frontends
-(web, CLI, SFTP and FTP). This means that you probably should not rely on
-all changes to files in the local directory to result in successful uploads.
-There might be (and have been) incompatible changes to how the feature is
-configured.
-
-We are very interested in feedback on how well this feature works for you, and
-suggestions to improve its usability, functionality, and reliability.
-
-.. _`Open Technology Fund`: https://www.opentech.fund/
-
-
-Configuration
-=============
-
-The Magic Folder frontend runs as part of a gateway node. To set it up, you
-must use the tahoe magic-folder CLI. For detailed information see our
-:doc:`Magic-Folder CLI design
-documentation<../proposed/magic-folder/user-interface-design>`. For a
-given Magic-Folder collective directory you need to run the ``tahoe
-magic-folder create`` command. After that the ``tahoe magic-folder invite``
-command must used to generate an *invite code* for each member of the
-magic-folder collective. A confidential, authenticated communications channel
-should be used to transmit the invite code to each member, who will be
-joining using the ``tahoe magic-folder join`` command.
-
-These settings are persisted in the ``[magic_folder]`` section of the
-gateway's ``tahoe.cfg`` file.
-
-``[magic_folder]``
-
-``enabled = (boolean, optional)``
-
-    If this is ``True``, Magic Folder will be enabled. The default value is
-    ``False``.
-
-``local.directory = (UTF-8 path)``
-
-    This specifies the local directory to be monitored for new or changed
-    files. If the path contains non-ASCII characters, it should be encoded
-    in UTF-8 regardless of the system's filesystem encoding. Relative paths
-    will be interpreted starting from the node's base directory.
-
-You should not normally need to set these fields manually because they are
-set by the ``tahoe magic-folder create`` and/or ``tahoe magic-folder join``
-commands. Use the ``--help`` option to these commands for more information.
-
-After setting up a Magic Folder collective and starting or restarting each
-gateway, you can confirm that the feature is working by copying a file into
-any local directory, and checking that it appears on other clients.
-Large files may take some time to appear.
-
-The 'Operational Statistics' page linked from the Welcome page shows counts
-of the number of files uploaded, the number of change events currently
-queued, and the number of failed uploads. The 'Recent Uploads and Downloads'
-page and the node :doc:`log<../logging>` may be helpful to determine the
-cause of any failures.
-
-
-.. _Known Issues in Magic-Folder:
-
-Known Issues and Limitations With Magic-Folder
-==============================================
-
-This feature only works on Linux and Windows. There is a ticket to add
-support for Mac OS X and BSD-based systems (`#1432`_).
-
-The only way to determine whether uploads have failed is to look at the
-'Operational Statistics' page linked from the Welcome page. This only shows
-a count of failures, not the names of files. Uploads are never retried.
-
-The Magic Folder frontend performs its uploads sequentially (i.e. it waits
-until each upload is finished before starting the next), even when there
-would be enough memory and bandwidth to efficiently perform them in parallel.
-A Magic Folder upload can occur in parallel with an upload by a different
-frontend, though. (`#1459`_)
-
-On Linux, if there are a large number of near-simultaneous file creation or
-change events (greater than the number specified in the file
-``/proc/sys/fs/inotify/max_queued_events``), it is possible that some events
-could be missed. This is fairly unlikely under normal circumstances, because
-the default value of ``max_queued_events`` in most Linux distributions is
-16384, and events are removed from this queue immediately without waiting for
-the corresponding upload to complete. (`#1430`_)
-
-The Windows implementation might also occasionally miss file creation or
-change events, due to limitations of the underlying Windows API
-(ReadDirectoryChangesW). We do not know how likely or unlikely this is.
-(`#1431`_)
-
-Some filesystems may not support the necessary change notifications.
-So, it is recommended for the local directory to be on a directly attached
-disk-based filesystem, not a network filesystem or one provided by a virtual
-machine.
-
-The ``private/magic_folder_dircap`` and ``private/collective_dircap`` files
-cannot use an alias or path to specify the upload directory. (`#1711`_)
-
-If a file in the upload directory is changed (actually relinked to a new
-file), then the old file is still present on the grid, and any other caps
-to it will remain valid. Eventually it will be possible to use
-:doc:`../garbage-collection` to reclaim the space used by these files; however
-currently they are retained indefinitely. (`#2440`_)
-
-Unicode filenames are supported on both Linux and Windows, but on Linux, the
-local name of a file must be encoded correctly in order for it to be uploaded.
-The expected encoding is that printed by
-``python -c "import sys; print sys.getfilesystemencoding()"``.
-
-On Windows, local directories with non-ASCII names are not currently working.
-(`#2219`_)
-
-On Windows, when a node has Magic Folder enabled, it is unresponsive to Ctrl-C
-(it can only be killed using Task Manager or similar). (`#2218`_)
-
-.. _`#1430`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1430
-.. _`#1431`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1431
-.. _`#1432`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1432
-.. _`#1459`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1459
-.. _`#1711`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1711
-.. _`#2218`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2218
-.. _`#2219`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2219
-.. _`#2440`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2440

docs/how_to_make_a_tahoe-lafs_release.org

@@ -17,13 +17,14 @@ people are Release Maintainers:
   - [ ] all appveyor checks pass
   - [ ] all buildbot workers pass their checks
 
-* freeze master branch [0/]
+* freeze master branch [0/1]
   - [ ] announced the freeze of the master branch on IRC (i.e. non-release PRs won't be merged until after release)
 
 * sync documentation [0/7]
-  - [ ] NEWS.rst: summarize user-visible changes, aim for one page of text
+
+  - [ ] NEWS.rst: (run "tox -e news")
   - [ ] added final release name and date to top-most item in NEWS.rst
-  - [ ] updated relnotes.txt
+  - [ ] updated relnotes.txt (change next, last versions; summarize NEWS)
   - [ ] updated CREDITS
   - [ ] updated docs/known_issues.rst
   - [ ] docs/INSTALL.rst only points to current tahoe-lafs-X.Y.Z.tar.gz source code file
@@ -35,7 +36,7 @@ people are Release Maintainers:
   - [ ] documentation is ready (see above)
   - [ ] (Release Maintainer): git tag -s -u 0xE34E62D06D0E69CFCA4179FFBDE0D31D68666A7A -m "release Tahoe-LAFS-X.Y.Z" tahoe-lafs-X.Y.Z
   - [ ] build code locally:
-     tox -e py27,codechecks,coverage,deprecations,docs,integration,upcoming-deprecations
+     tox -e py27,codechecks,deprecations,docs,integration,upcoming-deprecations
   - [ ] created tarballs (they'll be in dist/ for later comparison)
      tox -e tarballs
   - [ ] release version is reporting itself as intended version

docs/index.rst

@@ -20,11 +20,11 @@ Contents:
    frontends/CLI
    frontends/webapi
    frontends/FTP-and-SFTP
-   frontends/magic-folder
    frontends/download-status
 
    known_issues
    ../.github/CONTRIBUTING
+   CODE_OF_CONDUCT
 
    servers
    helper
@@ -37,9 +37,10 @@ Contents:
    expenses
    cautions
    write_coordination
-   magic-folder-howto
    backupdb
 
+   developer-guide
+
    anonymity-configuration
 
    nodekeys

docs/magic-folder-howto.rst

@@ -1,176 +0,0 @@
-.. _magic-folder-howto:
-
-=========================
-Magic Folder Set-up Howto
-=========================
-
-#.  `This document`_
-#.  `Setting up a local test grid`_
-#.  `Setting up Magic Folder`_
-#.  `Testing`_
-
-
-This document
-=============
-
-This is preliminary documentation of how to set up Magic Folder using a test
-grid on a single Linux or Windows machine, with two clients and one server.
-It is aimed at a fairly technical audience.
-
-For an introduction to Magic Folder and how to configure it
-more generally, see :doc:`frontends/magic-folder`.
-
-It it possible to adapt these instructions to run the nodes on
-different machines, to synchronize between three or more clients,
-to mix Windows and Linux clients, and to use multiple servers
-(if the Tahoe-LAFS encoding parameters are changed).
-
-
-Setting up a local test grid
-============================
-
-Linux
------
-
-Run these commands::
-
-  mkdir ../grid
-  bin/tahoe create-introducer ../grid/introducer
-  bin/tahoe start ../grid/introducer
-  export FURL=`cat ../grid/introducer/private/introducer.furl`
-  bin/tahoe create-node --introducer="$FURL" ../grid/server
-  bin/tahoe create-client --introducer="$FURL" ../grid/alice
-  bin/tahoe create-client --introducer="$FURL" ../grid/bob
-
-
-Windows
--------
-
-Run::
-
-  mkdir ..\grid
-  bin\tahoe create-introducer ..\grid\introducer
-  bin\tahoe start ..\grid\introducer
-
-Leave the introducer running in that Command Prompt,
-and in a separate Command Prompt (with the same current
-directory), run::
-
-  set /p FURL=<..\grid\introducer\private\introducer.furl
-  bin\tahoe create-node --introducer=%FURL% ..\grid\server
-  bin\tahoe create-client --introducer=%FURL% ..\grid\alice
-  bin\tahoe create-client --introducer=%FURL% ..\grid\bob
-
-
-Both Linux and Windows
-----------------------
-
-(Replace ``/`` with ``\`` for Windows paths.)
-
-Edit ``../grid/alice/tahoe.cfg``, and make the following
-changes to the ``[node]`` and ``[client]`` sections::
-
-  [node]
-  nickname = alice
-  web.port = tcp:3457:interface=127.0.0.1
-
-  [client]
-  shares.needed = 1
-  shares.happy = 1
-  shares.total = 1
-
-Edit ``../grid/bob/tahoe.cfg``, and make the following
-change to the ``[node]`` section, and the same change as
-above to the ``[client]`` section::
-
-  [node]
-  nickname = bob
-  web.port = tcp:3458:interface=127.0.0.1
-
-Note that when running nodes on a single machine,
-unique port numbers must be used for each node (and they
-must not clash with ports used by other server software).
-Here we have used the default of 3456 for the server,
-3457 for alice, and 3458 for bob.
-
-Now start all of the nodes (the introducer should still be
-running from above)::
-
-  bin/tahoe start ../grid/server
-  bin/tahoe start ../grid/alice
-  bin/tahoe start ../grid/bob
-
-On Windows, a separate Command Prompt is needed to run each
-node.
-
-Open a web browser on http://127.0.0.1:3457/ and verify that
-alice is connected to the introducer and one storage server.
-Then do the same for http://127.0.0.1:3568/ to verify that
-bob is connected. Leave all of the nodes running for the
-next stage.
-
-
-Setting up Magic Folder
-=======================
-
-Linux
------
-
-Run::
-
-  mkdir -p ../local/alice ../local/bob
-  bin/tahoe -d ../grid/alice magic-folder create magic: alice ../local/alice
-  bin/tahoe -d ../grid/alice magic-folder invite magic: bob >invitecode
-  export INVITECODE=`cat invitecode`
-  bin/tahoe -d ../grid/bob magic-folder join "$INVITECODE" ../local/bob
-
-  bin/tahoe restart ../grid/alice
-  bin/tahoe restart ../grid/bob
-
-Windows
--------
-
-Run::
-
-  mkdir ..\local\alice ..\local\bob
-  bin\tahoe -d ..\grid\alice magic-folder create magic: alice ..\local\alice
-  bin\tahoe -d ..\grid\alice magic-folder invite magic: bob >invitecode
-  set /p INVITECODE=<invitecode
-  bin\tahoe -d ..\grid\bob magic-folder join %INVITECODE% ..\local\bob
-
-Then close the Command Prompt windows that are running the alice and bob
-nodes, and open two new ones in which to run::
-
-  bin\tahoe start ..\grid\alice
-  bin\tahoe start ..\grid\bob
-
-
-Testing
-=======
-
-You can now experiment with creating files and directories in
-``../local/alice`` and ``/local/bob``; any changes should be
-propagated to the other directory.
-
-Note that when a file is deleted, the corresponding file in the
-other directory will be renamed to a filename ending in ``.backup``.
-Deleting a directory will have no effect.
-
-For other known issues and limitations, see :ref:`Known Issues in
-Magic-Folder`.
-
-As mentioned earlier, it is also possible to run the nodes on
-different machines, to synchronize between three or more clients,
-to mix Windows and Linux clients, and to use multiple servers
-(if the Tahoe-LAFS encoding parameters are changed).
-
-
-Configuration
-=============
-
-There will be a ``[magic_folder]`` section in your ``tahoe.cfg`` file
-after setting up Magic Folder.
-
-There is an option you can add to this called ``poll_interval=`` to
-control how often (in seconds) the Downloader will check for new things
-to download.

docs/magic-wormhole-invites.rst

@@ -19,9 +19,7 @@ Invites and Joins
 
 Inside Tahoe-LAFS we are using a channel created using `magic
 wormhole`_ to exchange configuration and the secret fURL of the
-Introducer with new clients. In the future, we would like to make the
+Introducer with new clients.
-Magic Folder (:ref:`Magic Folder HOWTO <magic-folder-howto>`) invites and joins work this way
-as well.
 
 This is a two-part process. Alice runs a grid and wishes to have her
 friend Bob use it as a client. She runs ``tahoe invite bob`` which

docs/proposed/index.rst

@@ -14,8 +14,4 @@ index only lists the files that are in .rst format.
    :maxdepth: 2
 
    leasedb
-   magic-folder/filesystem-integration
-   magic-folder/remote-to-local-sync
-   magic-folder/user-interface-design
-   magic-folder/multi-party-conflict-detection
    http-storage-node-protocol

docs/proposed/magic-folder/filesystem-integration.rst

@@ -1,118 +0,0 @@
-Magic Folder local filesystem integration design
-================================================
-
-*Scope*
-
-This document describes how to integrate the local filesystem with Magic
-Folder in an efficient and reliable manner. For now we ignore Remote to
-Local synchronization; the design and implementation of this is scheduled
-for a later time. We also ignore multiple writers for the same Magic
-Folder, which may or may not be supported in future. The design here will
-be updated to account for those features in later Objectives. Objective 3
-may require modifying the database schema or operation, and Objective 5
-may modify the User interface.
-
-Tickets on the Tahoe-LAFS trac with the `otf-magic-folder-objective2`_
-keyword are within the scope of the local filesystem integration for
-Objective 2.
-
-.. _otf-magic-folder-objective2: https://tahoe-lafs.org/trac/tahoe-lafs/query?status=!closed&keywords=~otf-magic-folder-objective2
-
-.. _filesystem_integration-local-scanning-and-database:
-
-*Local scanning and database*
-
-When a Magic-Folder-enabled node starts up, it scans all directories
-under the local directory and adds every file to a first-in first-out
-"scan queue". When processing the scan queue, redundant uploads are
-avoided by using the same mechanism the Tahoe backup command uses: we
-keep track of previous uploads by recording each file's metadata such as
-size, ``ctime`` and ``mtime``. This information is stored in a database,
-referred to from now on as the magic folder db. Using this recorded
-state, we ensure that when Magic Folder is subsequently started, the
-local directory tree can be scanned quickly by comparing current
-filesystem metadata with the previously recorded metadata. Each file
-referenced in the scan queue is uploaded only if its metadata differs at
-the time it is processed. If a change event is detected for a file that
-is already queued (and therefore will be processed later), the redundant
-event is ignored.
-
-To implement the magic folder db, we will use an SQLite schema that
-initially is the existing Tahoe-LAFS backup schema. This schema may
-change in later objectives; this will cause no backward compatibility
-problems, because this new feature will be developed on a branch that
-makes no compatibility guarantees. However we will have a separate SQLite
-database file and separate mutex lock just for Magic Folder. This avoids
-usability problems related to mutual exclusion. (If a single file and
-lock were used, a backup would block Magic Folder updates for a long
-time, and a user would not be able to tell when backups are possible
-because Magic Folder would acquire a lock at arbitrary times.)
-
-
-*Eventual consistency property*
-
-During the process of reading a file in order to upload it, it is not
-possible to prevent further local writes. Such writes will result in
-temporary inconsistency (that is, the uploaded file will not reflect
-what the contents of the local file were at any specific time). Eventual
-consistency is reached when the queue of pending uploads is empty. That
-is, a consistent snapshot will be achieved eventually when local writes
-to the target folder cease for a sufficiently long period of time.
-
-
-*Detecting filesystem changes*
-
-For the Linux implementation, we will use the `inotify`_ Linux kernel
-subsystem to gather events on the local Magic Folder directory tree. This
-implementation was already present in Tahoe-LAFS 1.9.0, but needs to be
-changed to gather directory creation and move events, in addition to the
-events indicating that a file has been written that are gathered by the
-current code.
-
-.. _`inotify`: https://en.wikipedia.org/wiki/Inotify
-
-For the Windows implementation, we will use the ``ReadDirectoryChangesW``
-Win32 API. The prototype implementation simulates a Python interface to
-the inotify API in terms of ``ReadDirectoryChangesW``, allowing most of
-the code to be shared across platforms.
-
-The alternative of using `NTFS Change Journals`_ for Windows was
-considered, but appears to be more complicated and does not provide any
-additional functionality over the scanning approach described above.
-The Change Journal mechanism is also only available for NTFS filesystems,
-but FAT32 filesystems are still common in user installations of Windows.
-
-.. _`NTFS Change Journals`: https://msdn.microsoft.com/en-us/library/aa363803%28VS.85%29.aspx
-
-When we detect the creation of a new directory below the local Magic
-Folder directory, we create it in the Tahoe-LAFS filesystem, and also
-scan the new local directory for new files. This scan is necessary to
-avoid missing events for creation of files in a new directory before it
-can be watched, and to correctly handle cases where an existing directory
-is moved to be under the local Magic Folder directory.
-
-
-*User interface*
-
-The Magic Folder local filesystem integration will initially have a
-provisional configuration file-based interface that may not be ideal from
-a usability perspective. Creating our local filesystem integration in
-this manner will allow us to use and test it independently of the rest of
-the Magic Folder software components. We will focus greater attention on
-user interface design as a later milestone in our development roadmap.
-
-The configuration file, ``tahoe.cfg``, must define a target local
-directory to be synchronized. Provisionally, this configuration will
-replace the current ``[drop_upload]`` section::
-
- [magic_folder]
- enabled = true
- local.directory = "/home/human"
-
-When a filesystem directory is first configured for Magic Folder, the user
-needs to create the remote Tahoe-LAFS directory using ``tahoe mkdir``,
-and configure the Magic-Folder-enabled node with its URI (e.g. by putting
-it in a file ``private/magic_folder_dircap``). If there are existing
-files in the local directory, they will be uploaded as a result of the
-initial scan described earlier.
-

docs/proposed/magic-folder/multi-party-conflict-detection.rst

@@ -1,373 +0,0 @@
-Multi-party Conflict Detection
-==============================
-
-The current Magic-Folder remote conflict detection design does not properly detect remote conflicts
-for groups of three or more parties. This design is specified in the "Fire Dragon" section of this document:
-https://github.com/tahoe-lafs/tahoe-lafs/blob/2551.wip.2/docs/proposed/magic-folder/remote-to-local-sync.rst#fire-dragons-distinguishing-conflicts-from-overwrites
-
-This Tahoe-LAFS trac ticket comment outlines a scenario with
-three parties in which a remote conflict is falsely detected:
-
-.. _`ticket comment`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2551#comment:22
-
-
-Summary and definitions
-=======================
-
-Abstract file: a file being shared by a Magic Folder.
-
-Local file: a file in a client's local filesystem corresponding to an abstract file.
-
-Relative path: the path of an abstract or local file relative to the Magic Folder root.
-
-Version: a snapshot of an abstract file, with associated metadata, that is uploaded by a Magic Folder client.
-
-A version is associated with the file's relative path, its contents, and
-mtime and ctime timestamps. Versions also have a unique identity.
-
-Follows relation:
-* If and only if a change to a client's local file at relative path F that results in an upload of version V',
-was made when the client already had version V of that file, then we say that V' directly follows V.
-* The follows relation is the irreflexive transitive closure of the "directly follows" relation.
-
-The follows relation is transitive and acyclic, and therefore defines a DAG called the
-Version DAG. Different abstract files correspond to disconnected sets of nodes in the Version DAG
-(in other words there are no "follows" relations between different files).
-
-The DAG is only ever extended, not mutated.
-
-The desired behaviour for initially classifying overwrites and conflicts is as follows:
-
-* if a client Bob currently has version V of a file at relative path F, and it sees a new version V'
-  of that file in another client Alice's DMD, such that V' follows V, then the write of the new version
-  is initially an overwrite and should be to the same filename.
-* if, in the same situation, V' does not follow V, then the write of the new version should be
-  classified as a conflict.
-
-The existing :doc:`remote-to-local-sync` document defines when an initial
-overwrite should be reclassified as a conflict.
-
-The above definitions completely specify the desired solution of the false
-conflict behaviour described in the `ticket comment`_. However, they do not give
-a concrete algorithm to compute the follows relation, or a representation in the
-Tahoe-LAFS file store of the metadata needed to compute it.
-
-We will consider two alternative designs, proposed by Leif Ryge and
-Zooko Wilcox-O'Hearn, that aim to fill this gap.
-
-
-
-Leif's Proposal: Magic-Folder "single-file" snapshot design
-===========================================================
-
-Abstract
---------
-
-We propose a relatively simple modification to the initial Magic Folder design which
-adds merkle DAGs of immutable historical snapshots for each file. The full history
-does not necessarily need to be retained, and the choice of how much history to retain
-can potentially be made on a per-file basis.
-
-Motivation:
------------
-
-no SPOFs, no admins
-```````````````````
-
-Additionally, the initial design had two cases of excess authority:
-
-1. The magic folder administrator (inviter) has everyone's write-caps and is thus essentially "root"
-2. Each client shares ambient authority and can delete anything or everything and
-   (assuming there is not a conflict) the data will be deleted from all clients. So, each client
-   is effectively "root" too.
-
-Thus, while it is useful for file synchronization, the initial design is a much less safe place
-to store data than in a single mutable tahoe directory (because more client computers have the
-possibility to delete it).
-
-
-Glossary
---------
-
-- merkle DAG: like a merkle tree but with multiple roots, and with each node potentially having multiple parents
-- magic folder: a logical directory that can be synchronized between many clients
-  (devices, users, ...) using a Tahoe-LAFS storage grid
-- client: a Magic-Folder-enabled Tahoe-LAFS client instance that has access to a magic folder
-- DMD: "distributed mutable directory", a physical Tahoe-LAFS mutable directory.
-  Each client has the write cap to their own DMD, and read caps to all other client's DMDs
-  (as in the original Magic Folder design).
-- snapshot: a reference to a version of a file; represented as an immutable directory containing
-  an entry called "content" (pointing to the immutable file containing the file's contents),
-  and an entry called "parent0" (pointing to a parent snapshot), and optionally parent1 through
-  parentN pointing at other parents. The Magic Folder snapshot object is conceptually very similar
-  to a git commit object, except for that it is created automatically and it records the history of an
-  individual file rather than an entire repository. Also, commits do not need to have authors
-  (although an author field could be easily added later).
-- deletion snapshot: immutable directory containing no content entry (only one or more parents)
-- capability: a Tahoe-LAFS diminishable cryptographic capability
-- cap: short for capability
-- conflict: the situation when another client's current snapshot for a file is different than our current snapshot, and is not a descendant of ours.
-- overwrite: the situation when another client's current snapshot for a file is a (not necessarily direct) descendant of our current snapshot.
-
-
-Overview
---------
-
-This new design will track the history of each file using "snapshots" which are
-created at each upload. Each snapshot will specify one or more parent snapshots,
-forming a directed acyclic graph. A Magic-Folder user's DMD uses a flattened directory
-hierarchy naming scheme, as in the original design. But, instead of pointing directly
-at file contents, each file name will link to that user's latest snapshot for that file.
-
-Inside the dmd there will also be an immutable directory containing the client's subscriptions
-(read-caps to other clients' dmds).
-
-Clients periodically poll each other's DMDs. When they see the current snapshot for a file is
-different than their own current snapshot for that file, they immediately begin downloading its
-contents and then walk backwards through the DAG from the new snapshot until they find their own
-snapshot or a common ancestor.
-
-For the common ancestor search to be efficient, the client will need to keep a local store (in the magic folder db) of all of the snapshots
-(but not their contents) between the oldest current snapshot of any of their subscriptions and their own current snapshot.
-See "local cache purging policy" below for more details.
-
-If the new snapshot is a descendant of the client's existing snapshot, then this update
-is an "overwrite" - like a git fast-forward. So, when the download of the new file completes it can overwrite
-the existing local file with the new contents and update its dmd to point at the new snapshot.
-
-If the new snapshot is not a descendant of the client's current snapshot, then the update is a
-conflict. The new file is downloaded and named $filename.conflict-$user1,$user2 (including a list
-of other subscriptions who have that version as their current version).
-
-Changes to the local .conflict- file are not tracked. When that file disappears
-(either by deletion, or being renamed) a new snapshot for the conflicting file is
-created which has two parents - the client's snapshot prior to the conflict, and the
-new conflicting snapshot. If multiple .conflict files are deleted or renamed in a short
-period of time, a single conflict-resolving snapshot with more than two parents can be created.
-
-! I think this behavior will confuse users. 
-
-Tahoe-LAFS snapshot objects
----------------------------
-
-These Tahoe-LAFS snapshot objects only track the history of a single file, not a directory hierarchy.
-Snapshot objects contain only two field types:
-- ``Content``: an immutable capability of the file contents (omitted if deletion snapshot)
-- ``Parent0..N``: immutable capabilities representing parent snapshots
-
-Therefore in this system an interesting side effect of this Tahoe snapshot object is that there is no
-snapshot author. The only notion of an identity in the Magic-Folder system is the write capability of the user's DMD.
-
-The snapshot object is an immutable directory which looks like this:
-content -> immutable cap to file content
-parent0 -> immutable cap to a parent snapshot object
-parent1..N -> more parent snapshots
-
-
-Snapshot Author Identity
-------------------------
-
-Snapshot identity might become an important feature so that bad actors
-can be recognized and other clients can stop "subscribing" to (polling for) updates from them.
-
-Perhaps snapshots could be signed by the user's Magic-Folder write key for this purpose? Probably a bad idea to reuse the write-cap key for this. Better to introduce ed25519 identity keys which can (optionally) sign snapshot contents and store the signature as another member of the immutable directory.
-
-
-Conflict Resolution
--------------------
-
-detection of conflicts
-``````````````````````
-
-A Magic-Folder client updates a given file's current snapshot link to a snapshot which is a descendent
-of the previous snapshot. For a given file, let's say "file1", Alice can detect that Bob's DMD has a "file1"
-that links to a snapshot which conflicts. Two snapshots conflict if one is not an ancestor of the other.
-
-
-a possible UI for resolving conflicts
-`````````````````````````````````````
-
-If Alice links a conflicting snapshot object for a file named "file1",
-Bob and Carole will see a file in their Magic-Folder called "file1.conflicted.Alice".
-Alice conversely will see an additional file called "file1.conflicted.previous".
-If Alice wishes to resolve the conflict with her new version of the file then
-she simply deletes the file called "file1.conflicted.previous". If she wants to
-choose the other version then she moves it into place:
-
-   mv file1.conflicted.previous file1
-
-
-This scheme works for N number of conflicts. Bob for instance could choose
-the same resolution for the conflict, like this:
-   
-   mv file1.Alice file1
-
-
-Deletion propagation and eventual Garbage Collection
-----------------------------------------------------
-
-When a user deletes a file, this is represented by a link from their DMD file
-object to a deletion snapshot. Eventually all users will link this deletion
-snapshot into their DMD. When all users have the link then they locally cache
-the deletion snapshot and remove the link to that file in their DMD.
-Deletions can of course be undeleted; this means creating a new snapshot
-object that specifies itself a descent of the deletion snapshot.
-
-Clients periodically renew leases to all capabilities recursively linked
-to in their DMD. Files which are unlinked by ALL the users of a
-given Magic-Folder will eventually be garbage collected.
-
-Lease expirey duration must be tuned properly by storage servers such that
-Garbage Collection does not occur too frequently.
-
-
-
-Performance Considerations
---------------------------
-
-local changes
-`````````````
-
-Our old scheme requires two remote Tahoe-LAFS operations per local file modification:
-1. upload new file contents (as an immutable file)
-2. modify mutable directory (DMD) to link to the immutable file cap
-
-Our new scheme requires three remote operations:
-1. upload new file contents (as in immutable file)
-2. upload immutable directory representing Tahoe-LAFS snapshot object
-3. modify mutable directory (DMD) to link to the immutable snapshot object
-
-remote changes
-``````````````
-
-Our old scheme requires one remote Tahoe-LAFS operation per remote file modification (not counting the polling of the dmd):
-1. Download new file content
-
-Our new scheme requires a minimum of two remote operations (not counting the polling of the dmd) for conflicting downloads, or three remote operations for overwrite downloads:
-1. Download new snapshot object
-2. Download the content it points to
-3. If the download is an overwrite, modify the DMD to indicate that the downloaded version is their current version.
-
-If the new snapshot is not a direct descendant of our current snapshot or the other party's previous snapshot we saw, we will also need to download more snapshots to determine if it is a conflict or an overwrite. However, those can be done in
-parallel with the content download since we will need to download the content in either case.
-
-While the old scheme is obviously more efficient, we think that the properties provided by the new scheme make it worth the additional cost.
-
-Physical updates to the DMD overiouslly need to be serialized, so multiple logical updates should be combined when an update is already in progress.
-
-conflict detection and local caching
-````````````````````````````````````
-
-Local caching of snapshots is important for performance.
-We refer to the client's local snapshot cache as the ``magic-folder db``.
-
-Conflict detection can be expensive because it may require the client
-to download many snapshots from the other user's DMD in order to try
-and find it's own current snapshot or a descendent. The cost of scanning
-the remote DMDs should not be very high unless the client conducting the
-scan has lots of history to download because of being offline for a long
-time while many new snapshots were distributed.
-
-
-local cache purging policy
-``````````````````````````
-
-The client's current snapshot for each file should be cached at all times.
-When all clients' views of a file are synchronized (they all have the same
-snapshot for that file), no ancestry for that file needs to be cached.
-When clients' views of a file are *not* synchronized, the most recent
-common ancestor of all clients' snapshots must be kept cached, as must
-all intermediate snapshots.
-
-
-Local Merge Property
---------------------
-
-Bob can in fact, set a pre-existing directory (with files) as his new Magic-Folder directory, resulting
-in a merge of the Magic-Folder with Bob's local directory. Filename collisions will result in conflicts
-because Bob's new snapshots are not descendent's of the existing Magic-Folder file snapshots.
-
-
-Example: simultaneous update with four parties:
-    
-1. A, B, C, D are in sync for file "foo" at snapshot X
-2. A and B simultaneously change the file, creating snapshots XA and XB (both descendants of X).
-3. C hears about XA first, and D hears about XB first. Both accept an overwrite.
-4. All four parties hear about the other update they hadn't heard about yet.
-5. Result:
-    - everyone's local file "foo" has the content pointed to by the snapshot in their DMD's "foo" entry
-    - A and C's DMDs each have the "foo" entry pointing at snapshot XA
-    - B and D's DMDs each have the "foo" entry pointing at snapshot XB
-    - A and C have a local file called foo.conflict-B,D with XB's content
-    - B and D have a local file called foo.conflict-A,C with XA's content
-
-Later:
-
-    - Everyone ignores the conflict, and continue updating their local "foo". but slowly enough that there are no further conflicts, so that A and C remain in sync with eachother, and B and D remain in sync with eachother.
-
-    - A and C's foo.conflict-B,D file continues to be updated with the latest version of the file B and D are working on, and vice-versa.
-
-    - A and C edit the file at the same time again, causing a new conflict.
-
-    - Local files are now:
-
-    A: "foo", "foo.conflict-B,D", "foo.conflict-C"
-
-    C: "foo", "foo.conflict-B,D", "foo.conflict-A"
-
-    B and D: "foo", "foo.conflict-A", "foo.conflict-C"
-
-    - Finally, D decides to look at "foo.conflict-A" and "foo.conflict-C", and they manually integrate (or decide to ignore) the differences into their own local file "foo".
-
-    - D deletes their conflict files.
-
-    - D's DMD now points to a snapshot that is a descendant of everyone else's current snapshot, resolving all conflicts.
-
-    - The conflict files on A, B, and C disappear, and everyone's local file "foo" contains D's manually-merged content.
-
-
-Daira: I think it is too complicated to include multiple nicknames in the .conflict files
-(e.g. "foo.conflict-B,D"). It should be sufficient to have one file for each other client,
-reflecting that client's latest version, regardless of who else it conflicts with.
-
-
-Zooko's Design (as interpreted by Daira)
-========================================
-
-A version map is a mapping from client nickname to version number.
-
-Definition: a version map M' strictly-follows a mapping M iff for every entry c->v
-in M, there is an entry c->v' in M' such that v' > v.
-
-
-Each client maintains a 'local version map' and a 'conflict version map' for each file
-in its magic folder db.
-If it has never written the file, then the entry for its own nickname in the local version
-map is zero. The conflict version map only contains entries for nicknames B where
-"$FILENAME.conflict-$B" exists.
-
-When a client A uploads a file, it increments the version for its own nickname in its
-local version map for the file, and includes that map as metadata with its upload.
-
-A download by client A from client B is an overwrite iff the downloaded version map
-strictly-follows A's local version map for that file; in this case A replaces its local
-version map with the downloaded version map. Otherwise it is a conflict, and the
-download is put into "$FILENAME.conflict-$B"; in this case A's
-local version map remains unchanged, and the entry B->v taken from the downloaded
-version map is added to its conflict version map.
-
-If client A deletes or renames a conflict file "$FILENAME.conflict-$B", then A copies
-the entry for B from its conflict version map to its local version map, deletes
-the entry for B in its conflict version map, and performs another upload (with
-incremented version number) of $FILENAME.
-
-
-Example:
-    A, B, C = (10, 20, 30) everyone agrees.
-    A updates: (11, 20, 30)
-    B updates: (10, 21, 30)
-
-C will see either A or B first. Both would be an overwrite, if considered alone.
-
-
-

docs/proposed/magic-folder/remote-to-local-sync.rst

@@ -1,951 +0,0 @@
-Magic Folder design for remote-to-local sync
-============================================
-
-Scope
------
-
-In this Objective we will design remote-to-local synchronization:
-
-* How to efficiently determine which objects (files and directories) have
-  to be downloaded in order to bring the current local filesystem into sync
-  with the newly-discovered version of the remote filesystem.
-* How to distinguish overwrites, in which the remote side was aware of
-  your most recent version and overwrote it with a new version, from
-  conflicts, in which the remote side was unaware of your most recent
-  version when it published its new version. The latter needs to be raised
-  to the user as an issue the user will have to resolve and the former must
-  not bother the user.
-* How to overwrite the (stale) local versions of those objects with the
-  newly acquired objects, while preserving backed-up versions of those
-  overwritten objects in case the user didn't want this overwrite and wants
-  to recover the old version.
-
-Tickets on the Tahoe-LAFS trac with the `otf-magic-folder-objective4`_
-keyword are within the scope of the remote-to-local synchronization
-design.
-
-.. _otf-magic-folder-objective4: https://tahoe-lafs.org/trac/tahoe-lafs/query?status=!closed&keywords=~otf-magic-folder-objective4
-
-
-Glossary
-''''''''
-
-Object: a file or directory
-
-DMD: distributed mutable directory
-
-Folder: an abstract directory that is synchronized between clients.
-(A folder is not the same as the directory corresponding to it on
-any particular client, nor is it the same as a DMD.)
-
-Collective: the set of clients subscribed to a given Magic Folder.
-
-Descendant: a direct or indirect child in a directory or folder tree
-
-Subfolder: a folder that is a descendant of a magic folder
-
-Subpath: the path from a magic folder to one of its descendants
-
-Write: a modification to a local filesystem object by a client
-
-Read: a read from a local filesystem object by a client
-
-Upload: an upload of a local object to the Tahoe-LAFS file store
-
-Download: a download from the Tahoe-LAFS file store to a local object
-
-Pending notification: a local filesystem change that has been detected
-but not yet processed.
-
-
-Representing the Magic Folder in Tahoe-LAFS
--------------------------------------------
-
-Unlike the local case where we use inotify or ReadDirectoryChangesW to
-detect filesystem changes, we have no mechanism to register a monitor for
-changes to a Tahoe-LAFS directory. Therefore, we must periodically poll
-for changes.
-
-An important constraint on the solution is Tahoe-LAFS' ":doc:`write
-coordination directive<../../write_coordination>`", which prohibits
-concurrent writes by different storage clients to the same mutable object:
-
-    Tahoe does not provide locking of mutable files and directories. If
-    there is more than one simultaneous attempt to change a mutable file
-    or directory, then an UncoordinatedWriteError may result. This might,
-    in rare cases, cause the file or directory contents to be accidentally
-    deleted.  The user is expected to ensure that there is at most one
-    outstanding write or update request for a given file or directory at
-    a time.  One convenient way to accomplish this is to make a different
-    file or directory for each person or process that wants to write.
-
-Since it is a goal to allow multiple users to write to a Magic Folder,
-if the write coordination directive remains the same as above, then we
-will not be able to implement the Magic Folder as a single Tahoe-LAFS
-DMD. In general therefore, we will have multiple DMDs —spread across
-clients— that together represent the Magic Folder. Each client in a
-Magic Folder collective polls the other clients' DMDs in order to detect
-remote changes.
-
-Six possible designs were considered for the representation of subfolders
-of the Magic Folder:
-
-1. All subfolders written by a given Magic Folder client are collapsed
-into a single client DMD, containing immutable files. The child name of
-each file encodes the full subpath of that file relative to the Magic
-Folder.
-
-2. The DMD tree under a client DMD is a direct copy of the folder tree
-written by that client to the Magic Folder. Not all subfolders have
-corresponding DMDs; only those to which that client has written files or
-child subfolders.
-
-3. The directory tree under a client DMD is a ``tahoe backup`` structure
-containing immutable snapshots of the folder tree written by that client
-to the Magic Folder. As in design 2, only objects written by that client
-are present.
-
-4. *Each* client DMD contains an eventually consistent mirror of all
-files and folders written by *any* Magic Folder client. Thus each client
-must also copy changes made by other Magic Folder clients to its own
-client DMD.
-
-5. *Each* client DMD contains a ``tahoe backup`` structure containing
-immutable snapshots of all files and folders written by *any* Magic
-Folder client. Thus each client must also create another snapshot in its
-own client DMD when changes are made by another client. (It can potentially
-batch changes, subject to latency requirements.)
-
-6. The write coordination problem is solved by implementing `two-phase
-commit`_. Then, the representation consists of a single DMD tree which is
-written by all clients.
-
-.. _`two-phase commit`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1755
-
-Here is a summary of advantages and disadvantages of each design:
-
-+----------------------------+
-| Key                        |
-+=======+====================+
-| \+\+  | major advantage    |
-+-------+--------------------+
-| \+    | minor advantage    |
-+-------+--------------------+
-| ‒     | minor disadvantage |
-+-------+--------------------+
-| ‒ ‒   | major disadvantage |
-+-------+--------------------+
-| ‒ ‒ ‒ | showstopper        |
-+-------+--------------------+
-
-
-123456+: All designs have the property that a recursive add-lease operation
-starting from a *collective directory* containing all of the client DMDs,
-will find all of the files and directories used in the Magic Folder
-representation. Therefore the representation is compatible with :doc:`garbage
-collection <../../garbage-collection>`, even when a pre-Magic-Folder client
-does the lease marking.
-
-123456+: All designs avoid "breaking" pre-Magic-Folder clients that read
-a directory or file that is part of the representation.
-
-456++: Only these designs allow a readcap to one of the client
-directories —or one of their subdirectories— to be directly shared
-with other Tahoe-LAFS clients (not necessarily Magic Folder clients),
-so that such a client sees all of the contents of the Magic Folder.
-Note that this was not a requirement of the OTF proposal, although it
-is useful.
-
-135+: A Magic Folder client has only one mutable Tahoe-LAFS object to
-monitor per other client. This minimizes communication bandwidth for
-polling, or alternatively the latency possible for a given polling
-bandwidth.
-
-1236+: A client does not need to make changes to its own DMD that repeat
-changes that another Magic Folder client had previously made. This reduces
-write bandwidth and complexity.
-
-1‒: If the Magic Folder has many subfolders, their files will all be
-collapsed into the same DMD, which could get quite large. In practice a
-single DMD can easily handle the number of files expected to be written
-by a client, so this is unlikely to be a significant issue.
-
-123‒ ‒: In these designs, the set of files in a Magic Folder is
-represented as the union of the files in all client DMDs. However,
-when a file is modified by more than one client, it will be linked
-from multiple client DMDs. We therefore need a mechanism, such as a
-version number or a monotonically increasing timestamp, to determine
-which copy takes priority.
-
-35‒ ‒: When a Magic Folder client detects a remote change, it must
-traverse an immutable directory structure to see what has changed.
-Completely unchanged subtrees will have the same URI, allowing some of
-this traversal to be shortcutted.
-
-24‒ ‒ ‒: When a Magic Folder client detects a remote change, it must
-traverse a mutable directory structure to see what has changed. This is
-more complex and less efficient than traversing an immutable structure,
-because shortcutting is not possible (each DMD retains the same URI even
-if a descendant object has changed), and because the structure may change
-while it is being traversed. Also the traversal needs to be robust
-against cycles, which can only occur in mutable structures.
-
-45‒ ‒: When a change occurs in one Magic Folder client, it will propagate
-to all the other clients. Each client will therefore see multiple
-representation changes for a single logical change to the Magic Folder
-contents, and must suppress the duplicates. This is particularly
-problematic for design 4 where it interacts with the preceding issue.
-
-4‒ ‒ ‒, 5‒ ‒: There is the potential for client DMDs to get "out of sync"
-with each other, potentially for long periods if errors occur. Thus each
-client must be able to "repair" its client directory (and its
-subdirectory structure) concurrently with performing its own writes. This
-is a significant complexity burden and may introduce failure modes that
-could not otherwise happen.
-
-6‒ ‒ ‒: While two-phase commit is a well-established protocol, its
-application to Tahoe-LAFS requires significant design work, and may still
-leave some corner cases of the write coordination problem unsolved.
-
-
-+------------------------------------------------+-----------------------------------------+
-| Design Property                                | Designs Proposed                        |
-+================================================+======+======+======+======+======+======+
-| **advantages**                                 | *1*  | *2*  | *3*  | *4*  | *5*  | *6*  |
-+------------------------------------------------+------+------+------+------+------+------+
-| Compatible with garbage collection             |\+    |\+    |\+    |\+    |\+    |\+    |
-+------------------------------------------------+------+------+------+------+------+------+
-| Does not break old clients                     |\+    |\+    |\+    |\+    |\+    |\+    |
-+------------------------------------------------+------+------+------+------+------+------+
-| Allows direct sharing                          |      |      |      |\+\+  |\+\+  |\+\+  |
-+------------------------------------------------+------+------+------+------+------+------+
-| Efficient use of bandwidth                     |\+    |      |\+    |      |\+    |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| No repeated changes                            |\+    |\+    |\+    |      |      |\+    |
-+------------------------------------------------+------+------+------+------+------+------+
-| **disadvantages**                              | *1*  | *2*  | *3*  | *4*  | *5*  | *6*  |
-+------------------------------------------------+------+------+------+------+------+------+
-| Can result in large DMDs                       |‒     |      |      |      |      |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| Need version number to determine priority      |‒ ‒   |‒ ‒   |‒ ‒   |      |      |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| Must traverse immutable directory structure    |      |      |‒ ‒   |      |‒ ‒   |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| Must traverse mutable directory structure      |      |‒ ‒ ‒ |      |‒ ‒ ‒ |      |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| Must suppress duplicate representation changes |      |      |      |‒ ‒   |‒ ‒   |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| "Out of sync" problem                          |      |      |      |‒ ‒ ‒ |‒ ‒   |      |
-+------------------------------------------------+------+------+------+------+------+------+
-| Unsolved design problems                       |      |      |      |      |      |‒ ‒ ‒ |
-+------------------------------------------------+------+------+------+------+------+------+
-
-
-Evaluation of designs
-'''''''''''''''''''''
-
-Designs 2 and 3 have no significant advantages over design 1, while
-requiring higher polling bandwidth and greater complexity due to the need
-to create subdirectories. These designs were therefore rejected.
-
-Design 4 was rejected due to the out-of-sync problem, which is severe
-and possibly unsolvable for mutable structures.
-
-For design 5, the out-of-sync problem is still present but possibly
-solvable. However, design 5 is substantially more complex, less efficient
-in bandwidth/latency, and less scalable in number of clients and
-subfolders than design 1. It only gains over design 1 on the ability to
-share directory readcaps to the Magic Folder (or subfolders), which was
-not a requirement. It would be possible to implement this feature in
-future by switching to design 6.
-
-For the time being, however, design 6 was considered out-of-scope for
-this project.
-
-Therefore, design 1 was chosen. That is:
-
-    All subfolders written by a given Magic Folder client are collapsed
-    into a single client DMD, containing immutable files. The child name
-    of each file encodes the full subpath of that file relative to the
-    Magic Folder.
-
-Each directory entry in a DMD also stores a version number, so that the
-latest version of a file is well-defined when it has been modified by
-multiple clients.
-
-To enable representing empty directories, a client that creates a
-directory should link a corresponding zero-length file in its DMD,
-at a name that ends with the encoded directory separator character.
-
-We want to enable dynamic configuration of the membership of a Magic
-Folder collective, without having to reconfigure or restart each client
-when another client joins. To support this, we have a single collective
-directory that links to all of the client DMDs, named by their client
-nicknames. If the collective directory is mutable, then it is possible
-to change its contents in order to add clients. Note that a client DMD
-should not be unlinked from the collective directory unless all of its
-files are first copied to some other client DMD.
-
-A client needs to be able to write to its own DMD, and read from other DMDs.
-To be consistent with the `Principle of Least Authority`_, each client's
-reference to its own DMD is a write capability, whereas its reference
-to the collective directory is a read capability. The latter transitively
-grants read access to all of the other client DMDs and the files linked
-from them, as required.
-
-.. _`Principle of Least Authority`: http://www.eros-os.org/papers/secnotsep.pdf
-
-Design and implementation of the user interface for maintaining this
-DMD structure and configuration will be addressed in Objectives 5 and 6.
-
-During operation, each client will poll for changes on other clients
-at a predetermined frequency. On each poll, it will reread the collective
-directory (to allow for added or removed clients), and then read each
-client DMD linked from it.
-
-"Hidden" files, and files with names matching the patterns used for backup,
-temporary, and conflicted files, will be ignored, i.e. not synchronized
-in either direction. A file is hidden if it has a filename beginning with
-"." (on any platform), or has the hidden or system attribute on Windows.
-
-
-Conflict Detection and Resolution
----------------------------------
-
-The combination of local filesystems and distributed objects is
-an example of shared state concurrency, which is highly error-prone
-and can result in race conditions that are complex to analyze.
-Unfortunately we have no option but to use shared state in this
-situation.
-
-We call the resulting design issues "dragons" (as in "Here be dragons"),
-which as a convenient mnemonic we have named after the classical
-Greek elements Earth, Fire, Air, and Water.
-
-Note: all filenames used in the following sections are examples,
-and the filename patterns we use in the actual implementation may
-differ. The actual patterns will probably include timestamps, and
-for conflicted files, the nickname of the client that last changed
-the file.
-
-
-Earth Dragons: Collisions between local filesystem operations and downloads
-'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-Write/download collisions
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Suppose that Alice's Magic Folder client is about to write a
-version of ``foo`` that it has downloaded in response to a remote
-change.
-
-The criteria for distinguishing overwrites from conflicts are
-described later in the `Fire Dragons`_ section. Suppose that the
-remote change has been initially classified as an overwrite.
-(As we will see, it may be reclassified in some circumstances.)
-
-.. _`Fire Dragons`: #fire-dragons-distinguishing-conflicts-from-overwrites
-
-Note that writing a file that does not already have an entry in the
-:ref:`magic folder db<filesystem_integration-local-scanning-and-database>` is
-initially classed as an overwrite.
-
-A *write/download collision* occurs when another program writes
-to ``foo`` in the local filesystem, concurrently with the new
-version being written by the Magic Folder client. We need to
-ensure that this does not cause data loss, as far as possible.
-
-An important constraint on the design is that on Windows, it is
-not possible to rename a file to the same name as an existing
-file in that directory. Also, on Windows it may not be possible to
-delete or rename a file that has been opened by another process
-(depending on the sharing flags specified by that process).
-Therefore we need to consider carefully how to handle failure
-conditions.
-
-In our proposed design, Alice's Magic Folder client follows
-this procedure for an overwrite in response to a remote change:
-
-1. Write a temporary file, say ``.foo.tmp``.
-2. Use the procedure described in the `Fire Dragons_` section
-   to obtain an initial classification as an overwrite or a
-   conflict. (This takes as input the ``last_downloaded_uri``
-   field from the directory entry of the changed ``foo``.)
-3. Set the ``mtime`` of the replacement file to be at least *T* seconds
-   before the current local time. Stat the replacement file
-   to obtain its ``mtime`` and ``ctime`` as stored in the local
-   filesystem, and update the file's last-seen statinfo in
-   the magic folder db with this information. (Note that the
-   retrieved ``mtime`` may differ from the one that was set due
-   to rounding.)
-4. Perform a ''file replacement'' operation (explained below)
-   with backup filename ``foo.backup``, replaced file ``foo``,
-   and replacement file ``.foo.tmp``. If any step of this
-   operation fails, reclassify as a conflict and stop.
-
-To reclassify as a conflict, attempt to rename ``.foo.tmp`` to
-``foo.conflicted``, suppressing errors.
-
-The implementation of file replacement differs between Unix
-and Windows. On Unix, it can be implemented as follows:
-
-* 4a. Stat the replaced path, and set the permissions of the
-  replacement file to be the same as the replaced file,
-  bitwise-or'd with octal 600 (``rw-------``). If the replaced
-  file does not exist, set the permissions according to the
-  user's umask. If there is a directory at the replaced path,
-  fail.
-* 4b. Attempt to move the replaced file (``foo``) to the
-  backup filename (``foo.backup``). If an ``ENOENT`` error
-  occurs because the replaced file does not exist, ignore this
-  error and continue with steps 4c and 4d.
-* 4c. Attempt to create a hard link at the replaced filename
-  (``foo``) pointing to the replacement file (``.foo.tmp``).
-* 4d. Attempt to unlink the replacement file (``.foo.tmp``),
-  suppressing errors.
-
-Note that, if there is no conflict, the entry for ``foo``
-recorded in the :ref:`magic folder
-db<filesystem_integration-local-scanning-and-database>` will
-reflect the ``mtime`` set in step 3. The move operation in step
-4b will cause a ``MOVED_FROM`` event for ``foo``, and the link
-operation in step 4c will cause an ``IN_CREATE`` event for
-``foo``. However, these events will not trigger an upload,
-because they are guaranteed to be processed only after the file
-replacement has finished, at which point the last-seen statinfo
-recorded in the database entry will exactly match the metadata
-for the file's inode on disk. (The two hard links — ``foo``
-and, while it still exists, ``.foo.tmp`` — share the same inode
-and therefore the same metadata.)
-
-On Windows, file replacement can be implemented by a call to
-the `ReplaceFileW`_ API (with the
-``REPLACEFILE_IGNORE_MERGE_ERRORS`` flag). If an error occurs
-because the replaced file does not exist, then we ignore this
-error and attempt to move the replacement file to the replaced
-file.
-
-Similar to the Unix case, the `ReplaceFileW`_ operation will
-cause one or more change notifications for ``foo``. The replaced
-``foo`` has the same ``mtime`` as the replacement file, and so any
-such notification(s) will not trigger an unwanted upload.
-
-.. _`ReplaceFileW`: https://msdn.microsoft.com/en-us/library/windows/desktop/aa365512%28v=vs.85%29.aspx
-
-To determine whether this procedure adequately protects against data
-loss, we need to consider what happens if another process attempts to
-update ``foo``, for example by renaming ``foo.other`` to ``foo``.
-This requires us to analyze all possible interleavings between the
-operations performed by the Magic Folder client and the other process.
-(Note that atomic operations on a directory are totally ordered.)
-The set of possible interleavings differs between Windows and Unix.
-
-On Unix, for the case where the replaced file already exists, we have:
-
-* Interleaving A: the other process' rename precedes our rename in
-  step 4b, and we get an ``IN_MOVED_TO`` event for its rename by
-  step 2. Then we reclassify as a conflict; its changes end up at
-  ``foo`` and ours end up at ``foo.conflicted``. This avoids data
-  loss.
-
-* Interleaving B: its rename precedes ours in step 4b, and we do
-  not get an event for its rename by step 2. Its changes end up at
-  ``foo.backup``, and ours end up at ``foo`` after being linked there
-  in step 4c. This avoids data loss.
-
-* Interleaving C: its rename happens between our rename in step 4b,
-  and our link operation in step 4c of the file replacement. The
-  latter fails with an ``EEXIST`` error because ``foo`` already
-  exists. We reclassify as a conflict; the old version ends up at
-  ``foo.backup``, the other process' changes end up at ``foo``, and
-  ours at ``foo.conflicted``. This avoids data loss.
-
-* Interleaving D: its rename happens after our link in step 4c, and
-  causes an ``IN_MOVED_TO`` event for ``foo``. Its rename also changes
-  the ``mtime`` for ``foo`` so that it is different from the ``mtime``
-  calculated in step 3, and therefore different from the metadata
-  recorded for ``foo`` in the magic folder db.  (Assuming no system
-  clock changes, its rename will set an ``mtime`` timestamp
-  corresponding to a time after step 4c, which is after the timestamp
-  *T* seconds before step 4a, provided that *T* seconds is
-  sufficiently greater than the timestamp granularity.)  Therefore, an
-  upload will be triggered for ``foo`` after its change, which is
-  correct and avoids data loss.
-
-If the replaced file did not already exist, an ``ENOENT`` error
-occurs at step 4b, and we continue with steps 4c and 4d. The other
-process' rename races with our link operation in step 4c. If the
-other process wins the race then the effect is similar to
-Interleaving C, and if we win the race this it is similar to
-Interleaving D. Either case avoids data loss.
-
-
-On Windows, the internal implementation of `ReplaceFileW`_ is similar
-to what we have described above for Unix; it works like this:
-
-* 4a′. Copy metadata (which does not include ``mtime``) from the
-  replaced file (``foo``) to the replacement file (``.foo.tmp``).
-
-* 4b′. Attempt to move the replaced file (``foo``) onto the
-  backup filename (``foo.backup``), deleting the latter if it
-  already exists.
-
-* 4c′. Attempt to move the replacement file (``.foo.tmp``) to the
-  replaced filename (``foo``); fail if the destination already
-  exists.
-
-Notice that this is essentially the same as the algorithm we use
-for Unix, but steps 4c and 4d on Unix are combined into a single
-step 4c′. (If there is a failure at steps 4c′ after step 4b′ has
-completed, the `ReplaceFileW`_ call will fail with return code
-``ERROR_UNABLE_TO_MOVE_REPLACEMENT_2``. However, it is still
-preferable to use this API over two `MoveFileExW`_ calls, because
-it retains the attributes and ACLs of ``foo`` where possible.
-Also note that if the `ReplaceFileW`_ call fails with
-``ERROR_FILE_NOT_FOUND`` because the replaced file does not exist,
-then the replacment operation ignores this error and continues with
-the equivalent of step 4c′, as on Unix.)
-
-However, on Windows the other application will not be able to
-directly rename ``foo.other`` onto ``foo`` (which would fail because
-the destination already exists); it will have to rename or delete
-``foo`` first. Without loss of generality, let's say ``foo`` is
-deleted. This complicates the interleaving analysis, because we
-have two operations done by the other process interleaving with
-three done by the magic folder process (rather than one operation
-interleaving with four as on Unix).
-
-So on Windows, for the case where the replaced file already exists,
-we have:
-
-* Interleaving A′: the other process' deletion of ``foo`` and its
-  rename of ``foo.other`` to ``foo`` both precede our rename in
-  step 4b. We get an event corresponding to its rename by step 2.
-  Then we reclassify as a conflict; its changes end up at ``foo``
-  and ours end up at ``foo.conflicted``. This avoids data loss.
-
-* Interleaving B′: the other process' deletion of ``foo`` and its
-  rename of ``foo.other`` to ``foo`` both precede our rename in
-  step 4b. We do not get an event for its rename by step 2.
-  Its changes end up at ``foo.backup``, and ours end up at ``foo``
-  after being moved there in step 4c′. This avoids data loss.
-
-* Interleaving C′: the other process' deletion of ``foo`` precedes
-  our rename of ``foo`` to ``foo.backup`` done by `ReplaceFileW`_,
-  but its rename of ``foo.other`` to ``foo`` does not, so we get
-  an ``ERROR_FILE_NOT_FOUND`` error from `ReplaceFileW`_ indicating
-  that the replaced file does not exist. We ignore this error and
-  attempt to move ``foo.tmp`` to ``foo``, racing with the other
-  process which is attempting to move ``foo.other`` to ``foo``.
-  If we win the race, then our changes end up at ``foo``, and the
-  other process' move fails. If the other process wins the race,
-  then its changes end up at ``foo``, our move fails, and we
-  reclassify as a conflict, so that our changes end up at
-  ``foo.conflicted``. Either possibility avoids data loss.
-
-* Interleaving D′: the other process' deletion and/or rename happen
-  during the call to `ReplaceFileW`_, causing the latter to fail.
-  There are two subcases:
-
-  * if the error is ``ERROR_UNABLE_TO_MOVE_REPLACEMENT_2``, then
-    ``foo`` is renamed to ``foo.backup`` and ``.foo.tmp`` remains
-    at its original name after the call.
-  * for all other errors, ``foo`` and ``.foo.tmp`` both remain at
-    their original names after the call.
-
-  In both subcases, we reclassify as a conflict and rename ``.foo.tmp``
-  to ``foo.conflicted``. This avoids data loss.
-
-* Interleaving E′: the other process' deletion of ``foo`` and attempt
-  to rename ``foo.other`` to ``foo`` both happen after all internal
-  operations of `ReplaceFileW`_ have completed. This causes deletion
-  and rename events for ``foo`` (which will in practice be merged due
-  to the pending delay, although we don't rely on that for
-  correctness).  The rename also changes the ``mtime`` for ``foo`` so
-  that it is different from the ``mtime`` calculated in step 3, and
-  therefore different from the metadata recorded for ``foo`` in the
-  magic folder db. (Assuming no system clock changes, its rename will
-  set an ``mtime`` timestamp corresponding to a time after the
-  internal operations of `ReplaceFileW`_ have completed, which is
-  after the timestamp *T* seconds before `ReplaceFileW`_ is called,
-  provided that *T* seconds is sufficiently greater than the timestamp
-  granularity.) Therefore, an upload will be triggered for ``foo``
-  after its change, which is correct and avoids data loss.
-
-.. _`MoveFileExW`: https://msdn.microsoft.com/en-us/library/windows/desktop/aa365240%28v=vs.85%29.aspx
-
-If the replaced file did not already exist, we get an
-``ERROR_FILE_NOT_FOUND`` error from `ReplaceFileW`_, and attempt to
-move ``foo.tmp`` to ``foo``. This is similar to Interleaving C, and
-either possibility for the resulting race avoids data loss.
-
-We also need to consider what happens if another process opens ``foo``
-and writes to it directly, rather than renaming another file onto it:
-
-* On Unix, open file handles refer to inodes, not paths. If the other
-  process opens ``foo`` before it has been renamed to ``foo.backup``,
-  and then closes the file, changes will have been written to the file
-  at the same inode, even if that inode is now linked at ``foo.backup``.
-  This avoids data loss.
-
-* On Windows, we have two subcases, depending on whether the sharing
-  flags specified by the other process when it opened its file handle
-  included ``FILE_SHARE_DELETE``. (This flag covers both deletion and
-  rename operations.)
-
-  i.  If the sharing flags *do not* allow deletion/renaming, the
-      `ReplaceFileW`_ operation will fail without renaming ``foo``.
-      In this case we will end up with ``foo`` changed by the other
-      process, and the downloaded file still in ``foo.tmp``.
-      This avoids data loss.
-
-  ii. If the sharing flags *do* allow deletion/renaming, then
-      data loss or corruption may occur. This is unavoidable and
-      can be attributed to other process making a poor choice of
-      sharing flags (either explicitly if it used `CreateFile`_, or
-      via whichever higher-level API it used).
-
-.. _`CreateFile`: https://msdn.microsoft.com/en-us/library/windows/desktop/aa363858%28v=vs.85%29.aspx
-
-Note that it is possible that another process tries to open the file
-between steps 4b and 4c (or 4b′ and 4c′ on Windows). In this case the
-open will fail because ``foo`` does not exist. Nevertheless, no data
-will be lost, and in many cases the user will be able to retry the
-operation.
-
-Above we only described the case where the download was initially
-classified as an overwrite. If it was classed as a conflict, the
-procedure is the same except that we choose a unique filename
-for the conflicted file (say, ``foo.conflicted_unique``). We write
-the new contents to ``.foo.tmp`` and then rename it to
-``foo.conflicted_unique`` in such a way that the rename will fail
-if the destination already exists. (On Windows this is a simple
-rename; on Unix it can be implemented as a link operation followed
-by an unlink, similar to steps 4c and 4d above.) If this fails
-because another process wrote ``foo.conflicted_unique`` after we
-chose the filename, then we retry with a different filename.
-
-
-Read/download collisions
-~~~~~~~~~~~~~~~~~~~~~~~~
-
-A *read/download collision* occurs when another program reads
-from ``foo`` in the local filesystem, concurrently with the new
-version being written by the Magic Folder client. We want to
-ensure that any successful attempt to read the file by the other
-program obtains a consistent view of its contents.
-
-On Unix, the above procedure for writing downloads is sufficient
-to achieve this. There are three cases:
-
-* A. The other process opens ``foo`` for reading before it is
-  renamed to ``foo.backup``. Then the file handle will continue to
-  refer to the old file across the rename, and the other process
-  will read the old contents.
-
-* B. The other process attempts to open ``foo`` after it has been
-  renamed to ``foo.backup``, and before it is linked in step c.
-  The open call fails, which is acceptable.
-
-* C. The other process opens ``foo`` after it has been linked to
-  the new file. Then it will read the new contents.
-
-On Windows, the analysis is very similar, but case A′ needs to
-be split into two subcases, depending on the sharing mode the other
-process uses when opening the file for reading:
-
-* A′. The other process opens ``foo`` before the Magic Folder
-  client's attempt to rename ``foo`` to ``foo.backup`` (as part
-  of the implementation of `ReplaceFileW`_). The subcases are:
-
-  i.  The other process uses sharing flags that deny deletion and
-      renames. The `ReplaceFileW`_ call fails, and the download is
-      reclassified as a conflict. The downloaded file ends up at
-      ``foo.conflicted``, which is correct.
-
-  ii. The other process uses sharing flags that allow deletion
-      and renames. The `ReplaceFileW`_ call succeeds, and the
-      other process reads inconsistent data. This can be attributed
-      to a poor choice of sharing flags by the other process.
-
-* B′. The other process attempts to open ``foo`` at the point
-  during the `ReplaceFileW`_ call where it does not exist.
-  The open call fails, which is acceptable.
-
-* C′. The other process opens ``foo`` after it has been linked to
-  the new file. Then it will read the new contents.
-
-
-For both write/download and read/download collisions, we have
-considered only interleavings with a single other process, and
-only the most common possibilities for the other process'
-interaction with the file. If multiple other processes are
-involved, or if a process performs operations other than those
-considered, then we cannot say much about the outcome in general;
-however, we believe that such cases will be much less common.
-
-
-
-Fire Dragons: Distinguishing conflicts from overwrites
-''''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-When synchronizing a file that has changed remotely, the Magic Folder
-client needs to distinguish between overwrites, in which the remote
-side was aware of your most recent version (if any) and overwrote it
-with a new version, and conflicts, in which the remote side was unaware
-of your most recent version when it published its new version. Those two
-cases have to be handled differently — the latter needs to be raised
-to the user as an issue the user will have to resolve and the former
-must not bother the user.
-
-For example, suppose that Alice's Magic Folder client sees a change
-to ``foo`` in Bob's DMD. If the version it downloads from Bob's DMD
-is "based on" the version currently in Alice's local filesystem at
-the time Alice's client attempts to write the downloaded file ‒or if
-there is no existing version in Alice's local filesystem at that time‒
-then it is an overwrite. Otherwise it is initially classified as a
-conflict.
-
-This initial classification is used by the procedure for writing a
-file described in the `Earth Dragons`_ section above. As explained
-in that section, we may reclassify an overwrite as a conflict if an
-error occurs during the write procedure.
-
-.. _`Earth Dragons`: #earth-dragons-collisions-between-local-filesystem-operations-and-downloads
-
-In order to implement this policy, we need to specify how the
-"based on" relation between file versions is recorded and updated.
-
-We propose to record this information:
-
-* in the :ref:`magic folder
-  db<filesystem_integration-local-scanning-and-database>`, for
-  local files;
-* in the Tahoe-LAFS directory metadata, for files stored in the
-  Magic Folder.
-
-In the magic folder db we will add a *last-downloaded record*,
-consisting of ``last_downloaded_uri`` and ``last_downloaded_timestamp``
-fields, for each path stored in the database. Whenever a Magic Folder
-client downloads a file, it stores the downloaded version's URI and
-the current local timestamp in this record. Since only immutable
-files are used, the URI will be an immutable file URI, which is
-deterministically and uniquely derived from the file contents and
-the Tahoe-LAFS node's :doc:`convergence secret<../../convergence-secret>`.
-
-(Note that the last-downloaded record is updated regardless of
-whether the download is an overwrite or a conflict. The rationale
-for this to avoid "conflict loops" between clients, where every
-new version after the first conflict would be considered as another
-conflict.)
-
-Later, in response to a local filesystem change at a given path, the
-Magic Folder client reads the last-downloaded record associated with
-that path (if any) from the database and then uploads the current
-file. When it links the uploaded file into its client DMD, it
-includes the ``last_downloaded_uri`` field in the metadata of the
-directory entry, overwriting any existing field of that name. If
-there was no last-downloaded record associated with the path, this
-field is omitted.
-
-Note that ``last_downloaded_uri`` field does *not* record the URI of
-the uploaded file (which would be redundant); it records the URI of
-the last download before the local change that caused the upload.
-The field will be absent if the file has never been downloaded by
-this client (i.e. if it was created on this client and no change
-by any other client has been detected).
-
-A possible refinement also takes into account the
-``last_downloaded_timestamp`` field from the magic folder db, and
-compares it to the timestamp of the change that caused the upload
-(which should be later, assuming no system clock changes).
-If the duration between these timestamps is very short, then we
-are uncertain about whether the process on Bob's system that wrote
-the local file could have taken into account the last download.
-We can use this information to be conservative about treating
-changes as conflicts. So, if the duration is less than a configured
-threshold, we omit the ``last_downloaded_uri`` field from the
-metadata. This will have the effect of making other clients treat
-this change as a conflict whenever they already have a copy of the
-file.
-
-Conflict/overwrite decision algorithm
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Now we are ready to describe the algorithm for determining whether a
-download for the file ``foo`` is an overwrite or a conflict (refining
-step 2 of the procedure from the `Earth Dragons`_ section).
-
-Let ``last_downloaded_uri`` be the field of that name obtained from
-the directory entry metadata for ``foo`` in Bob's DMD (this field
-may be absent). Then the algorithm is:
-
-* 2a. Attempt to "stat" ``foo`` to get its *current statinfo* (size
-  in bytes, ``mtime``, and ``ctime``). If Alice has no local copy
-  of ``foo``, classify as an overwrite.
-
-* 2b. Read the following information for the path ``foo`` from the
-  local magic folder db:
-
-  * the *last-seen statinfo*, if any (this is the size in
-    bytes, ``mtime``, and ``ctime`` stored in the ``local_files``
-    table when the file was last uploaded);
-  * the ``last_uploaded_uri`` field of the ``local_files`` table
-    for this file, which is the URI under which the file was last
-    uploaded.
-
-* 2c. If any of the following are true, then classify as a conflict:
-
-  * i. there are pending notifications of changes to ``foo``;
-  * ii. the last-seen statinfo is either absent (i.e. there is
-    no entry in the database for this path), or different from the
-    current statinfo;
-  * iii. either ``last_downloaded_uri`` or ``last_uploaded_uri``
-    (or both) are absent, or they are different.
-
-  Otherwise, classify as an overwrite.
-
-
-Air Dragons: Collisions between local writes and uploads
-''''''''''''''''''''''''''''''''''''''''''''''''''''''''
-
-Short of filesystem-specific features on Unix or the `shadow copy service`_
-on Windows (which is per-volume and therefore difficult to use in this
-context), there is no way to *read* the whole contents of a file
-atomically. Therefore, when we read a file in order to upload it, we
-may read an inconsistent version if it was also being written locally.
-
-.. _`shadow copy service`: https://technet.microsoft.com/en-us/library/ee923636%28v=ws.10%29.aspx
-
-A well-behaved application can avoid this problem for its writes:
-
-* On Unix, if another process modifies a file by renaming a temporary
-  file onto it, then we will consistently read either the old contents
-  or the new contents.
-* On Windows, if the other process uses sharing flags to deny reads
-  while it is writing a file, then we will consistently read either
-  the old contents or the new contents, unless a sharing error occurs.
-  In the case of a sharing error we should retry later, up to a
-  maximum number of retries.
-
-In the case of a not-so-well-behaved application writing to a file
-at the same time we read from it, the magic folder will still be
-eventually consistent, but inconsistent versions may be visible to
-other users' clients.
-
-In Objective 2 we implemented a delay, called the *pending delay*,
-after the notification of a filesystem change and before the file is
-read in order to upload it (Tahoe-LAFS ticket `#1440`_). If another
-change notification occurs within the pending delay time, the delay
-is restarted. This helps to some extent because it means that if
-files are written more quickly than the pending delay and less
-frequently than the pending delay, we shouldn't encounter this
-inconsistency.
-
-.. _`#1440`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1440
-
-The likelihood of inconsistency could be further reduced, even for
-writes by not-so-well-behaved applications, by delaying the actual
-upload for a further period —called the *stability delay*— after the
-file has finished being read. If a notification occurs between the
-end of the pending delay and the end of the stability delay, then
-the read would be aborted and the notification requeued.
-
-This would have the effect of ensuring that no write notifications
-have been received for the file during a time window that brackets
-the period when it was being read, with margin before and after
-this period defined by the pending and stability delays. The delays
-are intended to account for asynchronous notification of events, and
-caching in the filesystem.
-
-Note however that we cannot guarantee that the delays will be long
-enough to prevent inconsistency in any particular case. Also, the
-stability delay would potentially affect performance significantly
-because (unlike the pending delay) it is not overlapped when there
-are multiple files on the upload queue. This performance impact
-could be mitigated by uploading files in parallel where possible
-(Tahoe-LAFS ticket `#1459`_).
-
-We have not yet decided whether to implement the stability delay, and
-it is not planned to be implemented for the OTF objective 4 milestone.
-Ticket `#2431`_ has been opened to track this idea.
-
-.. _`#1459`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1459
-.. _`#2431`: https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2431
-
-Note that the situation of both a local process and the Magic Folder
-client reading a file at the same time cannot cause any inconsistency.
-
-
-Water Dragons: Handling deletion and renames
-''''''''''''''''''''''''''''''''''''''''''''
-
-Deletion of a file
-~~~~~~~~~~~~~~~~~~
-
-When a file is deleted from the filesystem of a Magic Folder client,
-the most intuitive behavior is for it also to be deleted under that
-name from other clients. To avoid data loss, the other clients should
-actually rename their copies to a backup filename.
-
-It would not be sufficient for a Magic Folder client that deletes
-a file to implement this simply by removing the directory entry from
-its DMD. Indeed, the entry may not exist in the client's DMD if it
-has never previously changed the file.
-
-Instead, the client links a zero-length file into its DMD and sets
-``deleted: true`` in the directory entry metadata. Other clients
-take this as a signal to rename their copies to the backup filename.
-
-Note that the entry for this zero-length file has a version number as
-usual, and later versions may restore the file.
-
-When the downloader deletes a file (or renames it to a filename
-ending in ``.backup``) in response to a remote change, a local
-filesystem notification will occur, and we must make sure that this
-is not treated as a local change. To do this we have the downloader
-set the ``size`` field in the magic folder db to ``None`` (SQL NULL)
-just before deleting the file, and suppress notifications for which
-the local file does not exist, and the recorded ``size`` field is
-``None``.
-
-When a Magic Folder client restarts, we can detect files that had
-been downloaded but were deleted while it was not running, because
-their paths will have last-downloaded records in the magic folder db
-with a ``size`` other than ``None``, and without any corresponding
-local file.
-
-Deletion of a directory
-~~~~~~~~~~~~~~~~~~~~~~~
-
-Local filesystems (unlike a Tahoe-LAFS filesystem) normally cannot
-unlink a directory that has any remaining children. Therefore a
-Magic Folder client cannot delete local copies of directories in
-general, because they will typically contain backup files. This must
-be done manually on each client if desired.
-
-Nevertheless, a Magic Folder client that deletes a directory should
-set ``deleted: true`` on the metadata entry for the corresponding
-zero-length file. This avoids the directory being recreated after
-it has been manually deleted from a client.
-
-Renaming
-~~~~~~~~
-
-It is sufficient to handle renaming of a file by treating it as a
-deletion and an addition under the new name.
-
-This also applies to directories, although users may find the
-resulting behavior unintuitive: all of the files under the old name
-will be renamed to backup filenames, and a new directory structure
-created under the new name. We believe this is the best that can be
-done without imposing unreasonable implementation complexity.
-
-
-Summary
--------
-
-This completes the design of remote-to-local synchronization.
-We realize that it may seem very complicated. Anecdotally, proprietary
-filesystem synchronization designs we are aware of, such as Dropbox,
-are said to incur similar or greater design complexity.

docs/proposed/magic-folder/user-interface-design.rst

@@ -1,205 +0,0 @@
-Magic Folder user interface design
-==================================
-
-Scope
------
-
-In this Objective we will design a user interface to allow users to conveniently
-and securely indicate which folders on some devices should be "magically" linked
-to which folders on other devices.
-
-This is a critical usability and security issue for which there is no known perfect
-solution, but which we believe is amenable to a "good enough" trade-off solution.
-This document explains the design and justifies its trade-offs in terms of security,
-usability, and time-to-market.
-
-Tickets on the Tahoe-LAFS trac with the `otf-magic-folder-objective6`_
-keyword are within the scope of the user interface design.
-
-.. _otf-magic-folder-objective6: https://tahoe-lafs.org/trac/tahoe-lafs/query?status=!closed&keywords=~otf-magic-folder-objective6
-
-Glossary
-''''''''
-
-Object: a file or directory
-
-DMD: distributed mutable directory
-
-Folder: an abstract directory that is synchronized between clients.
-(A folder is not the same as the directory corresponding to it on
-any particular client, nor is it the same as a DMD.)
-
-Collective: the set of clients subscribed to a given Magic Folder.
-
-Diminishing: the process of deriving, from an existing capability,
-another capability that gives less authority (for example, deriving a
-read cap from a read/write cap).
-
-
-Design Constraints
-------------------
-
-The design of the Tahoe-side representation of a Magic Folder, and the
-polling mechanism that the Magic Folder clients will use to detect remote
-changes was discussed in :doc:`remote-to-local-sync<remote-to-local-sync>`,
-and we will not revisit that here. The assumption made by that design was
-that each client would be configured with the following information:
-
-* a write cap to its own *client DMD*.
-* a read cap to a *collective directory*.
-
-The collective directory contains links to each client DMD named by the
-corresponding client's nickname.
-
-This design was chosen to allow straightforward addition of clients without
-requiring each existing client to change its configuration.
-
-Note that each client in a Magic Folder collective has the authority to add,
-modify or delete any object within the Magic Folder. It is also able to control
-to some extent whether its writes will be treated by another client as overwrites
-or as conflicts. However, there is still a reliability benefit to preventing a
-client from accidentally modifying another client's DMD, or from accidentally
-modifying the collective directory in a way that would lose data. This motivates
-ensuring that each client only has access to the caps above, rather than, say,
-every client having a write cap to the collective directory.
-
-Another important design constraint is that we cannot violate the :doc:`write
-coordination directive<../../write_coordination>`; that is, we cannot write to
-the same mutable directory from multiple clients, even during the setup phase
-when adding a client.
-
-Within these constraints, for usability we want to minimize the number of steps
-required to configure a Magic Folder collective.
-
-
-Proposed Design
----------------
-
-Three ``tahoe`` subcommands are added::
-
-  tahoe magic-folder create MAGIC: [MY_NICKNAME LOCAL_DIR]
-
-    Create an empty Magic Folder. The MAGIC: local alias is set
-    to a write cap which can be used to refer to this Magic Folder
-    in future ``tahoe magic-folder invite`` commands.
-
-    If MY_NICKNAME and LOCAL_DIR are given, the current client
-    immediately joins the newly created Magic Folder with that
-    nickname and local directory.
-
-
-  tahoe magic-folder invite MAGIC: THEIR_NICKNAME
-
-    Print an "invitation" that can be used to invite another
-    client to join a Magic Folder, with the given nickname.
-
-    The invitation must be sent to the user of the other client
-    over a secure channel (e.g. PGP email, OTR, or ssh).
-
-    This command will normally be run by the same client that
-    created the Magic Folder. However, it may be run by a
-    different client if the ``MAGIC:`` alias is copied to
-    the ``private/aliases`` file of that other client, or if
-    ``MAGIC:`` is replaced by the write cap to which it points.
-
-
-  tahoe magic-folder join INVITATION LOCAL_DIR
-
-    Accept an invitation created by ``tahoe magic-folder invite``.
-    The current client joins the specified Magic Folder, which will
-    appear in the local filesystem at the given directory.
-
-
-There are no commands to remove a client or to revoke an
-invitation, although those are possible features that could
-be added in future. (When removing a client, it is necessary
-to copy each file it added to some other client's DMD, if it
-is the most recent version of that file.)
-
-
-Implementation
-''''''''''''''
-
-For "``tahoe magic-folder create MAGIC: [MY_NICKNAME LOCAL_DIR]``" :
-
-1. Run "``tahoe create-alias MAGIC:``".
-2. If ``MY_NICKNAME`` and ``LOCAL_DIR`` are given, do the equivalent of::
-
-     INVITATION=`tahoe invite-magic-folder MAGIC: MY_NICKNAME`
-     tahoe join-magic-folder INVITATION LOCAL_DIR
-
-
-For "``tahoe magic-folder invite COLLECTIVE_WRITECAP NICKNAME``" :
-
-(``COLLECTIVE_WRITECAP`` can, as a special case, be an alias such as ``MAGIC:``.)
-
-1. Create an empty client DMD. Let its write URI be ``CLIENT_WRITECAP``.
-2. Diminish ``CLIENT_WRITECAP`` to ``CLIENT_READCAP``, and
-   diminish ``COLLECTIVE_WRITECAP`` to ``COLLECTIVE_READCAP``.
-3. Run "``tahoe ln CLIENT_READCAP COLLECTIVE_WRITECAP/NICKNAME``".
-4. Print "``COLLECTIVE_READCAP+CLIENT_WRITECAP``" as the invitation,
-   accompanied by instructions on how to accept the invitation and
-   the need to send it over a secure channel.
-
-
-For "``tahoe magic-folder join INVITATION LOCAL_DIR``" :
-
-1. Parse ``INVITATION`` as ``COLLECTIVE_READCAP+CLIENT_WRITECAP``.
-2. Write ``CLIENT_WRITECAP`` to the file ``magic_folder_dircap``
-   under the client's ``private`` directory.
-3. Write ``COLLECTIVE_READCAP`` to the file ``collective_dircap``
-   under the client's ``private`` directory.
-4. Edit the client's ``tahoe.cfg`` to set
-   ``[magic_folder] enabled = True`` and
-   ``[magic_folder] local.directory = LOCAL_DIR``.
-
-
-Discussion
-----------
-
-The proposed design has a minor violation of the
-`Principle of Least Authority`_ in order to reduce the number
-of steps needed. The invoker of "``tahoe magic-folder invite``"
-creates the client DMD on behalf of the invited client, and
-could retain its write cap (which is part of the invitation).
-
-.. _`Principle of Least Authority`: http://www.eros-os.org/papers/secnotsep.pdf
-
-A possible alternative design would be for the invited client
-to create its own client DMD, and send it back to the inviter
-to be linked into the collective directory. However this would
-require another secure communication and another command
-invocation per client. Given that, as mentioned earlier, each
-client in a Magic Folder collective already has the authority
-to add, modify or delete any object within the Magic Folder,
-we considered the potential security/reliability improvement
-here not to be worth the loss of usability.
-
-We also considered a design where each client had write access to
-the collective directory. This would arguably be a more serious
-violation of the Principle of Least Authority than the one above
-(because all clients would have excess authority rather than just
-the inviter). In any case, it was not clear how to make such a
-design satisfy the :doc:`write coordination
-directive<../../write_coordination>`, because the collective
-directory would have needed to be written to by multiple clients.
-
-The reliance on a secure channel to send the invitation to its
-intended recipient is not ideal, since it may involve additional
-software such as clients for PGP, OTR, ssh etc. However, we believe
-that this complexity is necessary rather than incidental, because
-there must be some way to distinguish the intended recipient from
-potential attackers who would try to become members of the Magic
-Folder collective without authorization. By making use of existing
-channels that have likely already been set up by security-conscious
-users, we avoid reinventing the wheel or imposing substantial extra
-implementation costs.
-
-The length of an invitation will be approximately the combined
-length of a Tahoe-LAFS read cap and write cap. This is several
-lines long, but still short enough to be cut-and-pasted successfully
-if care is taken. Errors in copying the invitation can be detected
-since Tahoe-LAFS cap URIs are self-authenticating.
-
-The implementation of the ``tahoe`` subcommands is straightforward
-and raises no further difficult design issues.

integration/conftest.py

@@ -8,6 +8,10 @@ from os.path import join, exists
 from tempfile import mkdtemp, mktemp
 from functools import partial
 
+from foolscap.furl import (
+    decode_furl,
+)
+
 from eliot import (
     to_file,
     log_call,
@@ -226,6 +230,16 @@ def introducer_furl(introducer, temp_dir):
         print("Don't see {} yet".format(furl_fname))
         sleep(.1)
     furl = open(furl_fname, 'r').read()
+    tubID, location_hints, name = decode_furl(furl)
+    if not location_hints:
+        # If there are no location hints then nothing can ever possibly
+        # connect to it and the only thing that can happen next is something
+        # will hang or time out.  So just give up right now.
+        raise ValueError(
+            "Introducer ({!r}) fURL has no location hints!".format(
+                introducer_furl,
+            ),
+        )
     return furl
 
 
@@ -332,11 +346,6 @@ def storage_nodes(reactor, temp_dir, introducer, introducer_furl, flog_gatherer,
 @pytest.fixture(scope='session')
 @log_call(action_type=u"integration:alice", include_args=[], include_result=False)
 def alice(reactor, temp_dir, introducer_furl, flog_gatherer, storage_nodes, request):
-    try:
-        mkdir(join(temp_dir, 'magic-alice'))
-    except OSError:
-        pass
-
     process = pytest_twisted.blockon(
         _create_node(
             reactor, request, temp_dir, introducer_furl, flog_gatherer, "alice",
@@ -351,11 +360,6 @@ def alice(reactor, temp_dir, introducer_furl, flog_gatherer, storage_nodes, requ
 @pytest.fixture(scope='session')
 @log_call(action_type=u"integration:bob", include_args=[], include_result=False)
 def bob(reactor, temp_dir, introducer_furl, flog_gatherer, storage_nodes, request):
-    try:
-        mkdir(join(temp_dir, 'magic-bob'))
-    except OSError:
-        pass
-
     process = pytest_twisted.blockon(
         _create_node(
             reactor, request, temp_dir, introducer_furl, flog_gatherer, "bob",
@@ -368,98 +372,10 @@ def bob(reactor, temp_dir, introducer_furl, flog_gatherer, storage_nodes, reques
 
 
 @pytest.fixture(scope='session')
-@log_call(action_type=u"integration:alice:invite", include_args=["temp_dir"])
+@pytest.mark.skipif(sys.platform.startswith('win'),
-def alice_invite(reactor, alice, temp_dir, request):
+                    'Tor tests are unstable on Windows')
-    node_dir = join(temp_dir, 'alice')
-
-    with start_action(action_type=u"integration:alice:magic_folder:create"):
-        # FIXME XXX by the time we see "client running" in the logs, the
-        # storage servers aren't "really" ready to roll yet (uploads fairly
-        # consistently fail if we don't hack in this pause...)
-        proto = _CollectOutputProtocol()
-        _tahoe_runner_optional_coverage(
-            proto,
-            reactor,
-            request,
-            [
-                'magic-folder', 'create',
-                '--poll-interval', '2',
-                '--basedir', node_dir, 'magik:', 'alice',
-                join(temp_dir, 'magic-alice'),
-            ]
-        )
-        pytest_twisted.blockon(proto.done)
-
-    with start_action(action_type=u"integration:alice:magic_folder:invite") as a:
-        proto = _CollectOutputProtocol()
-        _tahoe_runner_optional_coverage(
-            proto,
-            reactor,
-            request,
-            [
-                'magic-folder', 'invite',
-                '--basedir', node_dir, 'magik:', 'bob',
-            ]
-        )
-        pytest_twisted.blockon(proto.done)
-        invite = proto.output.getvalue()
-        a.add_success_fields(invite=invite)
-
-    with start_action(action_type=u"integration:alice:magic_folder:restart"):
-        # before magic-folder works, we have to stop and restart (this is
-        # crappy for the tests -- can we fix it in magic-folder?)
-        try:
-            alice.transport.signalProcess('TERM')
-            pytest_twisted.blockon(alice.transport.exited)
-        except ProcessExitedAlready:
-            pass
-        with start_action(action_type=u"integration:alice:magic_folder:magic-text"):
-            magic_text = 'Completed initial Magic Folder scan successfully'
-            pytest_twisted.blockon(_run_node(reactor, node_dir, request, magic_text))
-            await_client_ready(alice)
-    return invite
-
-
-@pytest.fixture(scope='session')
-@log_call(
-    action_type=u"integration:magic_folder",
-    include_args=["alice_invite", "temp_dir"],
-)
-def magic_folder(reactor, alice_invite, alice, bob, temp_dir, request):
-    print("pairing magic-folder")
-    bob_dir = join(temp_dir, 'bob')
-    proto = _CollectOutputProtocol()
-    _tahoe_runner_optional_coverage(
-        proto,
-        reactor,
-        request,
-        [
-            'magic-folder', 'join',
-            '--poll-interval', '1',
-            '--basedir', bob_dir,
-            alice_invite,
-            join(temp_dir, 'magic-bob'),
-        ]
-    )
-    pytest_twisted.blockon(proto.done)
-
-    # before magic-folder works, we have to stop and restart (this is
-    # crappy for the tests -- can we fix it in magic-folder?)
-    try:
-        print("Sending TERM to Bob")
-        bob.transport.signalProcess('TERM')
-        pytest_twisted.blockon(bob.transport.exited)
-    except ProcessExitedAlready:
-        pass
-
-    magic_text = 'Completed initial Magic Folder scan successfully'
-    pytest_twisted.blockon(_run_node(reactor, bob_dir, request, magic_text))
-    await_client_ready(bob)
-    return (join(temp_dir, 'magic-alice'), join(temp_dir, 'magic-bob'))
-
-
-@pytest.fixture(scope='session')
 def chutney(reactor, temp_dir):
+
     chutney_dir = join(temp_dir, 'chutney')
     mkdir(chutney_dir)
 
@@ -478,18 +394,39 @@ def chutney(reactor, temp_dir):
         proto,
         'git',
         (
-            'git', 'clone', '--depth=1',
+            'git', 'clone',
             'https://git.torproject.org/chutney.git',
             chutney_dir,
         ),
         env=environ,
     )
     pytest_twisted.blockon(proto.done)
+
+    # XXX: Here we reset Chutney to the last revision known to work
+    # with Python 2, as a workaround for Chutney moving to Python 3.
+    # When this is no longer necessary, we will have to drop this and
+    # add '--depth=1' back to the above 'git clone' subprocess.
+    proto = _DumpOutputProtocol(None)
+    reactor.spawnProcess(
+        proto,
+        'git',
+        (
+            'git', '-C', chutney_dir,
+            'reset', '--hard',
+            '99bd06c7554b9113af8c0877b6eca4ceb95dcbaa'
+        ),
+        env=environ,
+    )
+    pytest_twisted.blockon(proto.done)
+
     return chutney_dir
 
 
 @pytest.fixture(scope='session')
+@pytest.mark.skipif(sys.platform.startswith('win'),
+                    reason='Tor tests are unstable on Windows')
 def tor_network(reactor, temp_dir, chutney, request):
+
     # this is the actual "chutney" script at the root of a chutney checkout
     chutney_dir = chutney
     chut = join(chutney_dir, 'chutney')

integration/test_aaa_aardvark.py

@@ -16,7 +16,3 @@ def test_create_introducer(introducer):
 
 def test_create_storage(storage_nodes):
     print("Created {} storage nodes".format(len(storage_nodes)))
-
-
-def test_create_alice_bob_magicfolder(magic_folder):
-    print("Alice and Bob have paired magic-folders")

integration/test_magic_folder.py

@@ -1,462 +0,0 @@
-import sys
-import time
-import shutil
-from os import mkdir, unlink, utime
-from os.path import join, exists, getmtime
-
-import util
-
-import pytest_twisted
-
-
-# tests converted from check_magicfolder_smoke.py
-# see "conftest.py" for the fixtures (e.g. "magic_folder")
-
-def test_eliot_logs_are_written(alice, bob, temp_dir):
-    # The integration test configuration arranges for this logging
-    # configuration.  Verify it actually does what we want.
-    #
-    # The alice and bob arguments looks unused but they actually tell pytest
-    # to set up all the magic-folder stuff.  The assertions here are about
-    # side-effects of that setup.
-    assert exists(join(temp_dir, "alice", "logs", "eliot.json"))
-    assert exists(join(temp_dir, "bob", "logs", "eliot.json"))
-
-
-def test_alice_writes_bob_receives(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    with open(join(alice_dir, "first_file"), "w") as f:
-        f.write("alice wrote this")
-
-    util.await_file_contents(join(bob_dir, "first_file"), "alice wrote this")
-    return
-
-
-def test_alice_writes_bob_receives_multiple(magic_folder):
-    """
-    When Alice does a series of updates, Bob should just receive them
-    with no .backup or .conflict files being produced.
-    """
-    alice_dir, bob_dir = magic_folder
-
-    unwanted_files = [
-        join(bob_dir, "multiple.backup"),
-        join(bob_dir, "multiple.conflict")
-    ]
-
-    # first update
-    with open(join(alice_dir, "multiple"), "w") as f:
-        f.write("alice wrote this")
-
-    util.await_file_contents(
-        join(bob_dir, "multiple"), "alice wrote this",
-        error_if=unwanted_files,
-    )
-
-    # second update
-    with open(join(alice_dir, "multiple"), "w") as f:
-        f.write("someone changed their mind")
-
-    util.await_file_contents(
-        join(bob_dir, "multiple"), "someone changed their mind",
-        error_if=unwanted_files,
-    )
-
-    # third update
-    with open(join(alice_dir, "multiple"), "w") as f:
-        f.write("absolutely final version ship it")
-
-    util.await_file_contents(
-        join(bob_dir, "multiple"), "absolutely final version ship it",
-        error_if=unwanted_files,
-    )
-
-    # forth update, but both "at once" so one should conflict
-    time.sleep(2)
-    with open(join(alice_dir, "multiple"), "w") as f:
-        f.write("okay one more attempt")
-    with open(join(bob_dir, "multiple"), "w") as f:
-        f.write("...but just let me add")
-
-    bob_conflict = join(bob_dir, "multiple.conflict")
-    alice_conflict = join(alice_dir, "multiple.conflict")
-
-    found = util.await_files_exist([
-        bob_conflict,
-        alice_conflict,
-    ])
-
-    assert len(found) > 0, "Should have found a conflict"
-    print("conflict found (as expected)")
-
-
-def test_alice_writes_bob_receives_old_timestamp(magic_folder):
-    alice_dir, bob_dir = magic_folder
-    fname = join(alice_dir, "ts_file")
-    ts = time.time() - (60 * 60 * 36)  # 36 hours ago
-
-    with open(fname, "w") as f:
-        f.write("alice wrote this")
-    utime(fname, (time.time(), ts))
-
-    fname = join(bob_dir, "ts_file")
-    util.await_file_contents(fname, "alice wrote this")
-    # make sure the timestamp is correct
-    assert int(getmtime(fname)) == int(ts)
-    return
-
-
-def test_bob_writes_alice_receives(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    with open(join(bob_dir, "second_file"), "w") as f:
-        f.write("bob wrote this")
-
-    util.await_file_contents(join(alice_dir, "second_file"), "bob wrote this")
-    return
-
-
-def test_alice_deletes(magic_folder):
-    # alice writes a file, waits for bob to get it and then deletes it.
-    alice_dir, bob_dir = magic_folder
-
-    with open(join(alice_dir, "delfile"), "w") as f:
-        f.write("alice wrote this")
-
-    util.await_file_contents(join(bob_dir, "delfile"), "alice wrote this")
-
-    # bob has the file; now alices deletes it
-    unlink(join(alice_dir, "delfile"))
-
-    # bob should remove his copy, but preserve a backup
-    util.await_file_vanishes(join(bob_dir, "delfile"))
-    util.await_file_contents(join(bob_dir, "delfile.backup"), "alice wrote this")
-    return
-
-
-def test_alice_creates_bob_edits(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    # alice writes a file
-    with open(join(alice_dir, "editfile"), "w") as f:
-        f.write("alice wrote this")
-
-    util.await_file_contents(join(bob_dir, "editfile"), "alice wrote this")
-
-    # now bob edits it
-    with open(join(bob_dir, "editfile"), "w") as f:
-        f.write("bob says foo")
-
-    util.await_file_contents(join(alice_dir, "editfile"), "bob says foo")
-
-
-def test_bob_creates_sub_directory(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    # bob makes a sub-dir, with a file in it
-    mkdir(join(bob_dir, "subdir"))
-    with open(join(bob_dir, "subdir", "a_file"), "w") as f:
-        f.write("bob wuz here")
-
-    # alice gets it
-    util.await_file_contents(join(alice_dir, "subdir", "a_file"), "bob wuz here")
-
-    # now bob deletes it again
-    shutil.rmtree(join(bob_dir, "subdir"))
-
-    # alice should delete it as well
-    util.await_file_vanishes(join(alice_dir, "subdir", "a_file"))
-    # i *think* it's by design that the subdir won't disappear,
-    # because a "a_file.backup" should appear...
-    util.await_file_contents(join(alice_dir, "subdir", "a_file.backup"), "bob wuz here")
-
-
-def test_bob_creates_alice_deletes_bob_restores(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    # bob creates a file
-    with open(join(bob_dir, "boom"), "w") as f:
-        f.write("bob wrote this")
-
-    util.await_file_contents(
-        join(alice_dir, "boom"),
-        "bob wrote this"
-    )
-
-    # alice deletes it (so bob should as well .. but keep a backup)
-    unlink(join(alice_dir, "boom"))
-    util.await_file_vanishes(join(bob_dir, "boom"))
-    assert exists(join(bob_dir, "boom.backup"))
-
-    # bob restore it, with new contents
-    unlink(join(bob_dir, "boom.backup"))
-    with open(join(bob_dir, "boom"), "w") as f:
-        f.write("bob wrote this again, because reasons")
-
-    # XXX double-check this behavior is correct!
-
-    # alice sees bob's update, but marks it as a conflict (because
-    # .. she previously deleted it? does that really make sense)
-
-    util.await_file_contents(
-        join(alice_dir, "boom"),
-        "bob wrote this again, because reasons",
-    )
-
-
-def test_bob_creates_alice_deletes_alice_restores(magic_folder):
-    alice_dir, bob_dir = magic_folder
-
-    # bob creates a file
-    with open(join(bob_dir, "boom2"), "w") as f:
-        f.write("bob wrote this")
-
-    util.await_file_contents(
-        join(alice_dir, "boom2"),
-        "bob wrote this"
-    )
-
-    # alice deletes it (so bob should as well)
-    unlink(join(alice_dir, "boom2"))
-    util.await_file_vanishes(join(bob_dir, "boom2"))
-
-    # alice restore it, with new contents
-    with open(join(alice_dir, "boom2"), "w") as f:
-        f.write("alice re-wrote this again, because reasons")
-
-    util.await_file_contents(
-        join(bob_dir, "boom2"),
-        "alice re-wrote this again, because reasons"
-    )
-
-
-def test_bob_conflicts_with_alice_fresh(magic_folder):
-    # both alice and bob make a file at "the same time".
-    alice_dir, bob_dir = magic_folder
-
-    # either alice or bob will "win" by uploading to the DMD first.
-    with open(join(bob_dir, 'alpha'), 'w') as f0, open(join(alice_dir, 'alpha'), 'w') as f1:
-        f0.write("this is bob's alpha\n")
-        f1.write("this is alice's alpha\n")
-
-    # there should be conflicts
-    _bob_conflicts_alice_await_conflicts('alpha', alice_dir, bob_dir)
-
-
-def test_bob_conflicts_with_alice_preexisting(magic_folder):
-    # both alice and bob edit a file at "the same time" (similar to
-    # above, but the file already exists before the edits)
-    alice_dir, bob_dir = magic_folder
-
-    # have bob create the file
-    with open(join(bob_dir, 'beta'), 'w') as f:
-        f.write("original beta (from bob)\n")
-    util.await_file_contents(join(alice_dir, 'beta'), "original beta (from bob)\n")
-
-    # both alice and bob now have a "beta" file, at version 0
-
-    # either alice or bob will "win" by uploading to the DMD first
-    # (however, they should both detect a conflict)
-    with open(join(bob_dir, 'beta'), 'w') as f:
-        f.write("this is bob's beta\n")
-    with open(join(alice_dir, 'beta'), 'w') as f:
-        f.write("this is alice's beta\n")
-
-    # both alice and bob should see a conflict
-    _bob_conflicts_alice_await_conflicts("beta", alice_dir, bob_dir)
-
-
-def _bob_conflicts_alice_await_conflicts(name, alice_dir, bob_dir):
-    """
-    shared code between _fresh and _preexisting conflict test
-    """
-    found = util.await_files_exist(
-        [
-            join(bob_dir, '{}.conflict'.format(name)),
-            join(alice_dir, '{}.conflict'.format(name)),
-        ],
-    )
-
-    assert len(found) >= 1, "should be at least one conflict"
-    assert open(join(bob_dir, name), 'r').read() == "this is bob's {}\n".format(name)
-    assert open(join(alice_dir, name), 'r').read() == "this is alice's {}\n".format(name)
-
-    alice_conflict = join(alice_dir, '{}.conflict'.format(name))
-    bob_conflict = join(bob_dir, '{}.conflict'.format(name))
-    if exists(bob_conflict):
-        assert open(bob_conflict, 'r').read() == "this is alice's {}\n".format(name)
-    if exists(alice_conflict):
-        assert open(alice_conflict, 'r').read() == "this is bob's {}\n".format(name)
-
-
-@pytest_twisted.inlineCallbacks
-def test_edmond_uploads_then_restarts(reactor, request, temp_dir, introducer_furl, flog_gatherer, storage_nodes):
-    """
-    ticket 2880: if a magic-folder client uploads something, then
-    re-starts a spurious .backup file should not appear
-    """
-
-    edmond_dir = join(temp_dir, 'edmond')
-    edmond = yield util._create_node(
-        reactor, request, temp_dir, introducer_furl, flog_gatherer,
-        "edmond", web_port="tcp:9985:interface=localhost",
-        storage=False,
-    )
-
-
-    magic_folder = join(temp_dir, 'magic-edmond')
-    mkdir(magic_folder)
-    created = False
-    # create a magic-folder
-    # (how can we know that the grid is ready?)
-    for _ in range(10):  # try 10 times
-        try:
-            proto = util._CollectOutputProtocol()
-            transport = reactor.spawnProcess(
-                proto,
-                sys.executable,
-                [
-                    sys.executable, '-m', 'allmydata.scripts.runner',
-                    'magic-folder', 'create',
-                    '--poll-interval', '2',
-                    '--basedir', edmond_dir,
-                    'magik:',
-                    'edmond_magic',
-                    magic_folder,
-                ]
-            )
-            yield proto.done
-            created = True
-            break
-        except Exception as e:
-            print("failed to create magic-folder: {}".format(e))
-            time.sleep(1)
-
-    assert created, "Didn't create a magic-folder"
-
-    # to actually-start the magic-folder we have to re-start
-    edmond.transport.signalProcess('TERM')
-    yield edmond.transport.exited
-    edmond = yield util._run_node(reactor, edmond.node_dir, request, 'Completed initial Magic Folder scan successfully')
-    util.await_client_ready(edmond)
-
-    # add a thing to the magic-folder
-    with open(join(magic_folder, "its_a_file"), "w") as f:
-        f.write("edmond wrote this")
-
-    # fixme, do status-update attempts in a loop below
-    time.sleep(5)
-
-    # let it upload; poll the HTTP magic-folder status API until it is
-    # uploaded
-    from allmydata.scripts.magic_folder_cli import _get_json_for_fragment
-
-    with open(join(edmond_dir, u'private', u'api_auth_token'), 'rb') as f:
-        token = f.read()
-
-    uploaded = False
-    for _ in range(10):
-        options = {
-            "node-url": open(join(edmond_dir, u'node.url'), 'r').read().strip(),
-        }
-        try:
-            magic_data = _get_json_for_fragment(
-                options,
-                'magic_folder?t=json',
-                method='POST',
-                post_args=dict(
-                    t='json',
-                    name='default',
-                    token=token,
-                )
-            )
-            for mf in magic_data:
-                if mf['status'] == u'success' and mf['path'] == u'its_a_file':
-                    uploaded = True
-                    break
-        except Exception as e:
-            time.sleep(1)
-
-    assert uploaded, "expected to upload 'its_a_file'"
-
-    # re-starting edmond right now would "normally" trigger the 2880 bug
-
-    # kill edmond
-    edmond.transport.signalProcess('TERM')
-    yield edmond.transport.exited
-    time.sleep(1)
-    edmond = yield util._run_node(reactor, edmond.node_dir, request, 'Completed initial Magic Folder scan successfully')
-    util.await_client_ready(edmond)
-
-    # XXX how can we say for sure if we've waited long enough? look at
-    # tail of logs for magic-folder ... somethingsomething?
-    print("waiting 20 seconds to see if a .backup appears")
-    for _ in range(20):
-        assert exists(join(magic_folder, "its_a_file"))
-        assert not exists(join(magic_folder, "its_a_file.backup"))
-        time.sleep(1)
-
-
-@pytest_twisted.inlineCallbacks
-def test_alice_adds_files_while_bob_is_offline(reactor, request, temp_dir, magic_folder):
-    """
-    Alice can add new files to a magic folder while Bob is offline.  When Bob
-    comes back online his copy is updated to reflect the new files.
-    """
-    alice_magic_dir, bob_magic_dir = magic_folder
-    alice_node_dir = join(temp_dir, "alice")
-    bob_node_dir = join(temp_dir, "bob")
-
-    # Take Bob offline.
-    yield util.cli(request, reactor, bob_node_dir, "stop")
-
-    # Create a couple files in Alice's local directory.
-    some_files = list(
-        (name * 3) + ".added-while-offline"
-        for name
-        in "xyz"
-    )
-    for name in some_files:
-        with open(join(alice_magic_dir, name), "w") as f:
-            f.write(name + " some content")
-
-    good = False
-    for i in range(15):
-        status = yield util.magic_folder_cli(request, reactor, alice_node_dir, "status")
-        good = status.count(".added-while-offline (36 B): good, version=0") == len(some_files) * 2
-        if good:
-            # We saw each file as having a local good state and a remote good
-            # state.  That means we're ready to involve Bob.
-            break
-        else:
-            time.sleep(1.0)
-
-    assert good, (
-        "Timed out waiting for good Alice state.  Last status:\n{}".format(status)
-    )
-
-    # Start Bob up again
-    magic_text = 'Completed initial Magic Folder scan successfully'
-    yield util._run_node(reactor, bob_node_dir, request, magic_text)
-
-    yield util.await_files_exist(
-        list(
-            join(bob_magic_dir, name)
-            for name
-            in some_files
-        ),
-        await_all=True,
-    )
-    # Let it settle.  It would be nicer to have a readable status output we
-    # could query.  Parsing the current text format is more than I want to
-    # deal with right now.
-    time.sleep(1.0)
-    conflict_files = list(name + ".conflict" for name in some_files)
-    assert all(
-        list(
-            not exists(join(bob_magic_dir, name))
-            for name
-            in conflict_files
-        ),
-    )

integration/test_streaming_logs.py

@@ -53,7 +53,12 @@ class _StreamingLogClientProtocol(WebSocketClientProtocol):
         self.factory.on_open.callback(self)
 
     def onMessage(self, payload, isBinary):
-        self.on_message.callback(payload)
+        if self.on_message is None:
+            # Already did our job, ignore it
+            return
+        on_message = self.on_message
+        self.on_message = None
+        on_message.callback(payload)
 
     def onClose(self, wasClean, code, reason):
         self.on_close.callback(reason)
@@ -131,10 +136,13 @@ def _test_streaming_logs(reactor, temp_dir, alice):
     client.on_close = Deferred()
     client.on_message = Deferred()
 
+    # Capture this now before on_message perhaps goes away.
+    racing = _race(client.on_close, client.on_message)
+
     # Provoke _some_ log event.
     yield treq.get(node_url)
 
-    result = yield _race(client.on_close, client.on_message)
+    result = yield racing
 
     assert isinstance(result, Right)
     json.loads(result.value)

integration/test_tor.py

@@ -10,11 +10,20 @@ from six.moves import StringIO
 from twisted.internet.protocol import ProcessProtocol
 from twisted.internet.error import ProcessExitedAlready, ProcessDone
 from twisted.internet.defer import inlineCallbacks, Deferred
+
+import pytest
 import pytest_twisted
 
 import util
 
-# see "conftest.py" for the fixtures (e.g. "magic_folder")
+# see "conftest.py" for the fixtures (e.g. "tor_network")
+
+# XXX: Integration tests that involve Tor do not run reliably on
+# Windows.  They are skipped for now, in order to reduce CI noise.
+#
+# https://tahoe-lafs.org/trac/tahoe-lafs/ticket/3347
+if sys.platform.startswith('win'):
+    pytest.skip('Skipping Tor tests on Windows', allow_module_level=True)
 
 @pytest_twisted.inlineCallbacks
 def test_onion_service_storage(reactor, request, temp_dir, flog_gatherer, tor_network, tor_introducer_furl):

integration/test_web.py

@@ -219,23 +219,21 @@ def test_status(alice):
     found_upload = False
     found_download = False
     for href in hrefs:
-        if href.startswith(u"/") or not href:
+        if href == u"/" or not href:
             continue
-        resp = requests.get(
+        resp = requests.get(util.node_url(alice.node_dir, href))
-            util.node_url(alice.node_dir, u"status/{}".format(href)),
+        if href.startswith(u"/status/up"):
-        )
-        if href.startswith(u'up'):
             assert "File Upload Status" in resp.content
             if "Total Size: {}".format(len(FILE_CONTENTS)) in resp.content:
                 found_upload = True
-        elif href.startswith(u'down'):
+        elif href.startswith(u"/status/down"):
             assert "File Download Status" in resp.content
             if "Total Size: {}".format(len(FILE_CONTENTS)) in resp.content:
                 found_download = True
 
                 # download the specialized event information
                 resp = requests.get(
-                    util.node_url(alice.node_dir, u"status/{}/event_json".format(href)),
+                    util.node_url(alice.node_dir, u"{}/event_json".format(href)),
                 )
                 js = json.loads(resp.content)
                 # there's usually just one "read" operation, but this can handle many ..

integration/util.py

@@ -1,7 +1,7 @@
 import sys
 import time
 import json
-from os import mkdir
+from os import mkdir, environ
 from os.path import exists, join
 from six.moves import StringIO
 from functools import partial
@@ -145,6 +145,7 @@ def _tahoe_runner_optional_coverage(proto, reactor, request, other_args):
         proto,
         sys.executable,
         args,
+        env=environ,
     )
 
 
@@ -498,7 +499,3 @@ def await_client_ready(tahoe, timeout=10, liveness=60*2):
             tahoe,
         )
     )
-
-
-def magic_folder_cli(request, reactor, node_dir, *argv):
-    return cli(request, reactor, node_dir, "magic-folder", *argv)

misc/build_helpers/gen-package-table.py

@@ -156,6 +156,6 @@ for pkg in sorted(platform_independent_pkgs):
 print('</table>')
 
 # The document does validate, but not when it is included at the bottom of a directory listing.
-#print '<hr>'
+#print('<hr>')
-#print '<a href="http://validator.w3.org/check?uri=referer" target="_blank"><img border="0" src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a>'
+#print('<a href="http://validator.w3.org/check?uri=referer" target="_blank"><img border="0" src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a>')
 print('</body></html>')

misc/build_helpers/show-tool-versions.py

@@ -143,7 +143,6 @@ print_py_pkg_ver('coverage')
 print_py_pkg_ver('cryptography')
 print_py_pkg_ver('foolscap')
 print_py_pkg_ver('mock')
-print_py_pkg_ver('Nevow', 'nevow')
 print_py_pkg_ver('pyasn1')
 print_py_pkg_ver('pycparser')
 print_py_pkg_ver('cryptography')

misc/operations_helpers/provisioning/reliability.py

@@ -1,5 +1,7 @@
 #! /usr/bin/python
 
+from __future__ import print_function
+
 import math
 from allmydata.util import statistics
 from numpy import array, matrix, dot
@@ -72,11 +74,11 @@ class ReliabilityModel(object):
 
         repair = self.build_repair_matrix(k, N, R)
 
-        #print "DECAY:", decay
+        #print("DECAY:", decay)
-        #print "OLD-POST-REPAIR:", old_post_repair
+        #print("OLD-POST-REPAIR:", old_post_repair)
-        #print "NEW-POST-REPAIR:", decay * repair
+        #print("NEW-POST-REPAIR:", decay * repair)
-        #print "REPAIR:", repair
+        #print("REPAIR:", repair)
-        #print "DIFF:", (old_post_repair - decay * repair)
+        #print("DIFF:", (old_post_repair - decay * repair))
 
         START = array([0]*N + [1])
         DEAD = array([1]*k + [0]*(1+N-k))
@@ -85,9 +87,9 @@ class ReliabilityModel(object):
                                  [N-i for i in range(k, R)] +
                                  [0]*(1+N-R))
         assert REPAIR_newshares.shape[0] == N+1
-        #print "START", START
+        #print("START", START)
-        #print "REPAIRp", REPAIRp
+        #print("REPAIRp", REPAIRp)
-        #print "REPAIR_newshares", REPAIR_newshares
+        #print("REPAIR_newshares", REPAIR_newshares)
 
         unmaintained_state = START
         maintained_state = START
@@ -141,15 +143,15 @@ class ReliabilityModel(object):
         #    return "%dy.%dm" % (int(seconds/YEAR), int( (seconds%YEAR)/MONTH))
         #needed_repairs_total = sum(needed_repairs)
         #needed_new_shares_total = sum(needed_new_shares)
-        #print "at 2y:"
+        #print("at 2y:")
-        #print " unmaintained", unmaintained_state
+        #print(" unmaintained", unmaintained_state)
-        #print " maintained", maintained_state
+        #print(" maintained", maintained_state)
-        #print " number of repairs", needed_repairs_total
+        #print(" number of repairs", needed_repairs_total)
-        #print " new shares generated", needed_new_shares_total
+        #print(" new shares generated", needed_new_shares_total)
         #repair_rate_inv = report_span / needed_repairs_total
-        #print "  avg repair rate: once every %s" % yandm(repair_rate_inv)
+        #print("  avg repair rate: once every %s" % yandm(repair_rate_inv))
-        #print "  avg repair download: one share every %s" % yandm(repair_rate_inv/k)
+        #print("  avg repair download: one share every %s" % yandm(repair_rate_inv/k))
-        #print "  avg repair upload: one share every %s" % yandm(report_span / needed_new_shares_total)
+        #print("  avg repair upload: one share every %s" % yandm(report_span / needed_new_shares_total))
 
         return report
 

misc/operations_helpers/provisioning/test_provisioning.py

@@ -1,3 +1,4 @@
+from __future__ import print_function
 
 import unittest
 from allmydata import provisioning
@@ -99,7 +100,7 @@ class Reliability(unittest.TestCase):
         self.failUnlessEqual(len(r.samples), 20)
 
         last_row = r.samples[-1]
-        #print last_row
+        #print(last_row)
         (when, unmaintained_shareprobs, maintained_shareprobs,
          P_repaired_last_check_period,
          cumulative_number_of_repairs,

misc/python3/Makefile

@@ -0,0 +1,53 @@
+# Python 3 porting targets
+#
+# NOTE: this Makefile requires GNU make
+
+### Defensive settings for make:
+#     https://tech.davis-hansson.com/p/make/
+SHELL := bash
+.ONESHELL:
+.SHELLFLAGS := -xeu -o pipefail -c
+.SILENT:
+.DELETE_ON_ERROR:
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rules
+
+
+# Top-level, phony targets
+
+.PHONY: default
+default:
+	@echo "no default target"
+
+.PHONY: test-py3-all-before
+## Log the output of running all tests under Python 3 before changes
+test-py3-all-before: ../../.tox/make-test-py3-all-old.log
+.PHONY: test-py3-all-diff
+## Compare the output of running all tests under Python 3 after changes
+test-py3-all-diff: ../../.tox/make-test-py3-all.diff
+
+
+# Real targets
+
+# Gauge the impact of changes on Python 3 compatibility
+# Compare the output from running all tests under Python 3 before and after changes.
+# Before changes:
+# `$ rm -f .tox/make-test-py3-all-*.log && make .tox/make-test-py3-all-old.log`
+# After changes:
+# `$ make .tox/make-test-py3-all.diff`
+$(foreach side,old new,../../.tox/make-test-py3-all-$(side).log):
+	cd "../../"
+	tox --develop --notest -e py36-coverage
+	(make VIRTUAL_ENV=./.tox/py36-coverage TEST_SUITE=allmydata \
+		test-venv-coverage || true) | \
+		sed -E 's/\([0-9]+\.[0-9]{3} secs\)/(#.### secs)/' | \
+		tee "./misc/python3/$(@)"
+../../.tox/make-test-py3-all.diff: ../../.tox/make-test-py3-all-new.log
+	(diff -u "$(<:%-new.log=%-old.log)" "$(<)" || true) | tee "$(@)"
+
+# Locate modules that are candidates for naively converting `unicode` -> `str`.
+# List all Python source files that reference `unicode` but don't reference `str`
+../../.tox/py3-unicode-no-str.ls:
+	cd "../../"
+	find src -type f -iname '*.py' -exec grep -l -E '\Wunicode\W' '{}' ';' | \
+		xargs grep -L '\Wstr\W' | xargs ls -ld | tee "./misc/python3/$(@)"

misc/python3/audit-dict-for-loops.py

@@ -0,0 +1,43 @@
+"""
+The following code is valid in Python 2:
+
+for x in my_dict.keys():
+    if something(x):
+        del my_dict[x]
+
+But broken in Python 3.
+
+One solution is:
+
+for x in list(my_dict.keys()):
+    if something(x):
+        del my_dict[x]
+
+Some but not all code in Tahoe has been changed to that. In other cases, the code was left unchanged since there was no `del`.
+
+However, some mistakes may have slept through.
+
+To help catch cases that were incorrectly ported, this script runs futurize on all ported modules, which should convert it into the `list()` form.
+You can then look at git diffs to see if any of the impacted would be buggy without the newly added `list()`.
+"""
+
+import os
+from subprocess import check_call
+
+from allmydata.util import _python3
+
+
+def fix_potential_issue():
+    for module in _python3.PORTED_MODULES + _python3.PORTED_TEST_MODULES:
+        filename = "src/" + module.replace(".", "/") + ".py"
+        if not os.path.exists(filename):
+            # Package, probably
+            filename = "src/" + module.replace(".", "/") + "/__init__.py"
+        check_call(["futurize", "-f", "lib2to3.fixes.fix_dict", "-w", filename])
+    print(
+        "All loops converted. Check diff to see if there are any that need to be commitedd."
+    )
+
+
+if __name__ == "__main__":
+    fix_potential_issue()

misc/python3/tahoe-depgraph.py

@@ -60,7 +60,8 @@ class mymf(modulefinder.ModuleFinder):
                 self._depgraph[last_caller.__name__].add(fqname)
         return r
 
-    def load_module(self, fqname, fp, pathname, (suffix, mode, type)):
+    def load_module(self, fqname, fp, pathname, additional_info):
+        (suffix, mode, type) = additional_info
         r = modulefinder.ModuleFinder.load_module(
             self, fqname, fp, pathname, (suffix, mode, type))
         if r is not None:
@@ -71,7 +72,7 @@ class mymf(modulefinder.ModuleFinder):
         return {
             'depgraph': {
                 name: dict.fromkeys(deps, 1)
-                for name, deps in self._depgraph.iteritems()},
+                for name, deps in self._depgraph.items()},
             'types': self._types,
         }
 
@@ -101,20 +102,25 @@ def main(target):
                 filepath = path
             moduleNames.append(reflect.filenameToModuleName(filepath))
 
-    with tempfile.NamedTemporaryFile() as tmpfile:
+    with tempfile.NamedTemporaryFile("w") as tmpfile:
         for moduleName in moduleNames:
             tmpfile.write('import %s\n' % moduleName)
         tmpfile.flush()
         mf.run_script(tmpfile.name)
 
-    with open('tahoe-deps.json', 'wb') as outfile:
+    with open('tahoe-deps.json', 'w') as outfile:
         json_dump(mf.as_json(), outfile)
         outfile.write('\n')
 
-    ported_modules_path = os.path.join(target, "src", "allmydata", "ported-modules.txt")
+    ported_modules_path = os.path.join(target, "src", "allmydata", "util", "_python3.py")
-    with open(ported_modules_path) as ported_modules:
+    with open(ported_modules_path) as f:
-        port_status = dict.fromkeys((line.strip() for line in ported_modules), "ported")
+        ported_modules = {}
-    with open('tahoe-ported.json', 'wb') as outfile:
+        exec(f.read(), ported_modules, ported_modules)
+        port_status = dict.fromkeys(
+            ported_modules["PORTED_MODULES"] + ported_modules["PORTED_TEST_MODULES"],
+            "ported"
+        )
+    with open('tahoe-ported.json', 'w') as outfile:
         json_dump(port_status, outfile)
         outfile.write('\n')
 

misc/simulators/bench_spans.py

@@ -74,7 +74,7 @@ class B(object):
             count += 1
             inline = self.inf.readline()
 
-        # print self.stats
+        # print(self.stats)
 
 benchutil.print_bench_footer(UNITS_PER_SECOND=1000000)
 print("(microseconds)")

misc/simulators/count_dirs.py

@@ -89,9 +89,9 @@ def scan(root):
     num_files = 0
     num_dirs = 0
     for absroot, dirs, files in os.walk(root):
-        #print absroot
+        #print(absroot)
-        #print " %d files" % len(files)
+        #print(" %d files" % len(files))
-        #print " %d subdirs" % len(dirs)
+        #print(" %d subdirs" % len(dirs))
         num_files += len(files)
         num_dirs += len(dirs)
         stringsize = len(''.join(files) + ''.join(dirs))

misc/simulators/hashbasedsig.py

@@ -146,8 +146,8 @@ def calculate(K, K1, K2, q_max, L_hash, trees):
             lg_q = lg(q_cand)
             lg_pforge = [lg_px[x] + (lg_q*x - lg_K2)*q_cand for x in xrange(1, j)]
             if max(lg_pforge) < -L_hash + lg(j) and lg_px[j-1] + 1.0 < -L_hash:
-                #print "K = %d, K1 = %d, K2 = %d, L_hash = %d, lg_K2 = %.3f, q = %d, lg_pforge_1 = %.3f, lg_pforge_2 = %.3f, lg_pforge_3 = %.3f" \
+                #print("K = %d, K1 = %d, K2 = %d, L_hash = %d, lg_K2 = %.3f, q = %d, lg_pforge_1 = %.3f, lg_pforge_2 = %.3f, lg_pforge_3 = %.3f"
-                #      % (K, K1, K2, L_hash, lg_K2, q, lg_pforge_1, lg_pforge_2, lg_pforge_3)
+                #      % (K, K1, K2, L_hash, lg_K2, q, lg_pforge_1, lg_pforge_2, lg_pforge_3))
                 q = q_cand
                 break
 
@@ -268,7 +268,7 @@ def search():
                         trees[y] = (h, c_y, (dau, tri))
 
         #for x in xrange(1, K_max+1):
-        #    print x, trees[x]
+        #    print(x, trees[x])
 
         candidates = []
         progress = 0

misc/simulators/ringsim.py

@@ -130,8 +130,8 @@ class Ring(object):
         # used is actual per-server ciphertext
         usedpf = [1.0*u/numfiles for u in used]
         # usedpf is actual per-server-per-file ciphertext
-        #print "min/max usage: %s/%s" % (abbreviate_space(used[-1]),
+        #print("min/max usage: %s/%s" % (abbreviate_space(used[-1]),
-        #                                abbreviate_space(used[0]))
+        #                                abbreviate_space(used[0])))
         avg_usage_per_file = avg_space_per_file/len(self.servers)
         # avg_usage_per_file is expected per-server-per-file ciphertext
         spreadpf = usedpf[0] - usedpf[-1]
@@ -146,7 +146,7 @@ class Ring(object):
             abbreviate_space(avg_usage_per_file) ), end=' ')
         print("spread-pf: %s (%.2f%%)" % (
             abbreviate_space(spreadpf), 100.0*spreadpf/avg_usage_per_file), end=' ')
-        #print "average_usage:", abbreviate_space(average_usagepf)
+        #print("average_usage:", abbreviate_space(average_usagepf))
         print("stddev: %s (%.2f%%)" % (abbreviate_space(std_deviation),
                                        100.0*sd_of_total))
         if self.SHOW_MINMAX:
@@ -176,14 +176,14 @@ def do_run(ring, opts):
     for filenum in count(0):
         #used = list(reversed(sorted([s.used for s in ring.servers])))
         #used = [s.used for s in ring.servers]
-        #print used
+        #print(used)
         si = myhash(fileseed+str(filenum)).hexdigest()
         filesize = make_up_a_file_size(si)
         sharesize = filesize / opts["k"]
         if filenum%4000==0 and filenum > 1:
             ring.dump_usage(filenum, avg_space_per_file)
         servers = ring.servers_for_si(si)
-        #print ring.show_servers(servers[:opts["N"]])
+        #print(ring.show_servers(servers[:opts["N"]]))
         remaining_shares = opts["N"]
         index = 0
         server_was_full = False

misc/simulators/simulate_load.py

@@ -59,7 +59,7 @@ def go(permutedpeerlist):
                     server.full_at_tick = tick
                     fullservers += 1
                     if fullservers == len(servers):
-                        # print "Couldn't place share -- all servers full.  Stopping."
+                        # print("Couldn't place share -- all servers full.  Stopping.")
                         return (servers, doubled_up_shares)
 
             i += 1

misc/simulators/sizes.py

@@ -96,9 +96,9 @@ class Sizes(object):
             # means storing (and eventually transmitting) more hashes. This
             # count includes all the low-level share hashes and the root.
             hash_nodes = (num_leaves*k - 1) / (k - 1)
-            #print "hash_depth", d
+            #print("hash_depth", d)
-            #print "num_leaves", num_leaves
+            #print("num_leaves", num_leaves)
-            #print "hash_nodes", hash_nodes
+            #print("hash_nodes", hash_nodes)
             # the storage overhead is this
             self.share_storage_overhead = 32 * (hash_nodes - 1)
             # the transmission overhead is smaller: if we actually transmit

newsfragments/1432.feature

@@ -1 +0,0 @@
-Magic-Folders are now supported on macOS.

newsfragments/1792.feature

@@ -0,0 +1 @@
+PyPy is now a supported platform.

newsfragments/1827.removed

@@ -1 +0,0 @@
-"tahoe rm", an old alias for "tahoe unlink", has been removed.

newsfragments/2098.removed

@@ -1 +0,0 @@
-The direct dependencies on pyutil and zbase32 have been removed.

newsfragments/2392.removed

@@ -1 +0,0 @@
-The redundant "pypywin32" dependency has been removed.

newsfragments/2479.other

@@ -1 +0,0 @@
-Tahoe-LAFS now tests for PyPy compatibility on CI.

newsfragments/2749.installation

@@ -1 +0,0 @@
-Tahoe-LAFS no longer makes start-up time assertions about the versions of its dependencies.  It is the responsibility of the administrator of the installation to ensure the correct version of dependencies are supplied.

newsfragments/2755.other

@@ -0,0 +1 @@
+The Tahoe-LAFS project has adopted a formal code of conduct.

newsfragments/2771.other

@@ -1 +0,0 @@
-Tahoe-LAFS now requires Twisted 18.4.0 or newer.

newsfragments/2870.bugfix

@@ -1 +0,0 @@
-refactor initialization code to be more async-friendly

newsfragments/2908.other

@@ -1 +0,0 @@
-Tahoe-LAFS now uses towncrier to maintain the NEWS file.

newsfragments/2920.other

@@ -1 +0,0 @@
-The release process document has been updated.

newsfragments/2933.other

@@ -1 +0,0 @@
-allmydata.test.test_system.SystemTest is now more reliable with respect to bound address collisions.

newsfragments/2935.bugfix

@@ -1 +0,0 @@
-Configuration-checking code wasn't being called due to indenting

newsfragments/2936.bugfix

@@ -1 +0,0 @@
-refactor configuration handling out of Node into _Config

newsfragments/2941.bugfix

@@ -1 +0,0 @@
-"tox -e codechecks" no longer dirties the working tree.

newsfragments/2942.feature

@@ -1 +0,0 @@
-Add a "tox -e draftnews" which runs towncrier in draft mode

newsfragments/2944.bugfix

@@ -1 +0,0 @@
-Updated the Tor release key, used by the integration tests.

newsfragments/2950.bugfix

@@ -1 +0,0 @@
-`tahoe backup` no longer fails with an unhandled exception when it encounters a special file (device, fifo) in the backup source.

newsfragments/2955.feature

@@ -1 +0,0 @@
-Fedora 29 is now tested as part of the project's continuous integration system.

newsfragments/2955.removed

@@ -1 +0,0 @@
-Fedora 27 is no longer tested as part of the project's continuous integration system.

newsfragments/2956.other

@@ -1 +0,0 @@
-The Tox configuration has been fixed to work around a problem on Windows CI.

newsfragments/2957.installation

@@ -1 +0,0 @@
-Tahoe-LAFS now depends on Twisted 16.6 or newer.

newsfragments/2958.other

@@ -1 +0,0 @@
-The PyInstaller CI job now works around a pip/pyinstaller incompatibility.

newsfragments/2959.other

@@ -1 +0,0 @@
-Some CI jobs for integration tests have been moved from TravisCI to CircleCI.

newsfragments/2960.other

@@ -1 +0,0 @@
-Several warnings from a new release of pyflakes have been fixed.

newsfragments/2961.other

@@ -1 +0,0 @@
-Some Slackware 14.2 continuous integration problems have been resolved.

newsfragments/2962.other

@@ -1 +0,0 @@
-Some macOS continuous integration failures have been fixed.

newsfragments/2965.bugfix

@@ -1 +0,0 @@
-Magic-Folders now creates spurious conflict files in fewer cases.  In particular, if files are added to the folder while a client is offline, that client will not create conflict files for all those new files when it starts up.

newsfragments/2966.other

@@ -1 +0,0 @@
-The NoNetworkGrid implementation has been somewhat improved.

newsfragments/2967.other

@@ -1 +0,0 @@
-A bug in the test suite for the create-alias command has been fixed.

newsfragments/2968.other

@@ -1 +0,0 @@
-The integration test suite has been updated to use pytest-twisted instead of deprecated pytest APIs.

newsfragments/2969.other

@@ -1 +0,0 @@
-The magic-folder integration test suite now performs more aggressive cleanup of the processes it launches.

newsfragments/2970.other

@@ -1 +0,0 @@
-The integration tests now correctly document the `--keep-tempdir` option.

newsfragments/2971.other

@@ -1 +0,0 @@
-A misuse of super() in the integration tests has been fixed.

newsfragments/2972.feature

@@ -1 +0,0 @@
-The Magic-Folder frontend now emits structured, causal logs.  This makes it easier for developers to make sense of its behavior and for users to submit useful debugging information alongside problem reports.

newsfragments/2973.other

@@ -1 +0,0 @@
-Several utilities to facilitate the use of the Eliot causal logging library have been introduced.

newsfragments/2974.other

@@ -1 +0,0 @@
-The Windows CI configuration has been tweaked.

newsfragments/2975.feature

@@ -1 +0,0 @@
-The `tahoe` CLI now accepts arguments for configuring structured logging messages which Tahoe-LAFS is being converted to emit.  This change does not introduce any new defaults for on-filesystem logging.

newsfragments/2976.bugfix

@@ -1 +0,0 @@
-The confusing and misplaced sub-command group headings in `tahoe --help` output have been removed.

newsfragments/2977.other

@@ -1 +0,0 @@
-The Magic-Folder frontend has had additional logging improvements.

newsfragments/2997.bugfix

@@ -1 +0,0 @@
-The Magic-Folder frontend is now more responsive to subtree changes on Windows.

newsfragments/3001.other

@@ -1 +0,0 @@
-Added a simple sytax checker so that once a file has reached python3 compatibility, it will not regress.

newsfragments/3002.other

@@ -1 +0,0 @@
-Converted all uses of the print statement to the print function in the ./misc/ directory.

newsfragments/3003.other

@@ -1 +0,0 @@
-The contributor guidelines are now linked from the GitHub pull request creation page.