Reorganize code so allmydata.web.check_results can import without Nevow being installed.

src/allmydata/web/check_results.py

@@ -14,7 +14,7 @@ from twisted.web.template import (
     renderElement,
     tags,
 )
-from allmydata.web.common import (
+from allmydata.web.common_py3 import (
     exception_to_child,
     get_arg,
     get_root,
@@ -22,8 +22,8 @@ from allmydata.web.common import (
     WebError,
     MultiFormatResource,
     SlotsSequenceElement,
+    ReloadMixin,
 )
-from allmydata.web.operations import ReloadMixin
 from allmydata.interfaces import (
     ICheckAndRepairResults,
     ICheckResults,

src/allmydata/web/common.py

@@ -7,39 +7,27 @@ from twisted.web import (
     http,
     resource,
     server,
-    template,
 )
 from twisted.python import log
 from nevow import appserver
 from nevow.inevow import IRequest
-from allmydata import blacklist
 from allmydata.interfaces import (
-    EmptyPathnameComponentError,
-    ExistingChildError,
-    FileTooLargeError,
-    MustBeDeepImmutableError,
-    MustBeReadonlyError,
-    MustNotBeUnknownRWError,
-    NoSharesError,
-    NoSuchChildError,
-    NotEnoughSharesError,
     MDMF_VERSION,
     SDMF_VERSION,
 )
-from allmydata.mutable.common import UnrecoverableFileError
 from allmydata.util.hashutil import timing_safe_compare
 from allmydata.util.time_format import (
     format_delta,
     format_time,
 )
 from allmydata.util.encodingutil import (
-    quote_output,
     to_bytes,
 )
 
 # Originally part of this module, so still part of its API:
 from .common_py3 import (  # noqa: F401
-    get_arg, abbreviate_time, MultiFormatResource, WebError,
+    get_arg, abbreviate_time, MultiFormatResource, WebError, humanize_exception,
+    SlotsSequenceElement, render_exception, get_root, exception_to_child
 )
 
 
@@ -117,13 +105,6 @@ def parse_offset_arg(offset):
     return offset
 
 
-def get_root(ctx_or_req):
-    req = IRequest(ctx_or_req)
-    depth = len(req.prepath) + len(req.postpath)
-    link = "/".join([".."] * depth)
-    return link
-
-
 def convert_children_json(nodemaker, children_json):
     """I convert the JSON output of GET?t=json into the dict-of-nodes input
     to both dirnode.create_subdirectory() and
@@ -217,94 +198,6 @@ def should_create_intermediate_directories(req):
     return bool(req.method in ("PUT", "POST") and
                 t not in ("delete", "rename", "rename-form", "check"))
 
-def humanize_exception(exc):
-    """
-    Like ``humanize_failure`` but for an exception.
-
-    :param Exception exc: The exception to describe.
-
-    :return: See ``humanize_failure``.
-    """
-    if isinstance(exc, EmptyPathnameComponentError):
-        return ("The webapi does not allow empty pathname components, "
-                "i.e. a double slash", http.BAD_REQUEST)
-    if isinstance(exc, ExistingChildError):
-        return ("There was already a child by that name, and you asked me "
-                "to not replace it.", http.CONFLICT)
-    if isinstance(exc, NoSuchChildError):
-        quoted_name = quote_output(exc.args[0], encoding="utf-8", quotemarks=False)
-        return ("No such child: %s" % quoted_name, http.NOT_FOUND)
-    if isinstance(exc, NotEnoughSharesError):
-        t = ("NotEnoughSharesError: This indicates that some "
-             "servers were unavailable, or that shares have been "
-             "lost to server departure, hard drive failure, or disk "
-             "corruption. You should perform a filecheck on "
-             "this object to learn more.\n\nThe full error message is:\n"
-             "%s") % str(exc)
-        return (t, http.GONE)
-    if isinstance(exc, NoSharesError):
-        t = ("NoSharesError: no shares could be found. "
-             "Zero shares usually indicates a corrupt URI, or that "
-             "no servers were connected, but it might also indicate "
-             "severe corruption. You should perform a filecheck on "
-             "this object to learn more.\n\nThe full error message is:\n"
-             "%s") % str(exc)
-        return (t, http.GONE)
-    if isinstance(exc, UnrecoverableFileError):
-        t = ("UnrecoverableFileError: the directory (or mutable file) could "
-             "not be retrieved, because there were insufficient good shares. "
-             "This might indicate that no servers were connected, "
-             "insufficient servers were connected, the URI was corrupt, or "
-             "that shares have been lost due to server departure, hard drive "
-             "failure, or disk corruption. You should perform a filecheck on "
-             "this object to learn more.")
-        return (t, http.GONE)
-    if isinstance(exc, MustNotBeUnknownRWError):
-        quoted_name = quote_output(exc.args[1], encoding="utf-8")
-        immutable = exc.args[2]
-        if immutable:
-            t = ("MustNotBeUnknownRWError: an operation to add a child named "
-                 "%s to a directory was given an unknown cap in a write slot.\n"
-                 "If the cap is actually an immutable readcap, then using a "
-                 "webapi server that supports a later version of Tahoe may help.\n\n"
-                 "If you are using the webapi directly, then specifying an immutable "
-                 "readcap in the read slot (ro_uri) of the JSON PROPDICT, and "
-                 "omitting the write slot (rw_uri), would also work in this "
-                 "case.") % quoted_name
-        else:
-            t = ("MustNotBeUnknownRWError: an operation to add a child named "
-                 "%s to a directory was given an unknown cap in a write slot.\n"
-                 "Using a webapi server that supports a later version of Tahoe "
-                 "may help.\n\n"
-                 "If you are using the webapi directly, specifying a readcap in "
-                 "the read slot (ro_uri) of the JSON PROPDICT, as well as a "
-                 "writecap in the write slot if desired, would also work in this "
-                 "case.") % quoted_name
-        return (t, http.BAD_REQUEST)
-    if isinstance(exc, MustBeDeepImmutableError):
-        quoted_name = quote_output(exc.args[1], encoding="utf-8")
-        t = ("MustBeDeepImmutableError: a cap passed to this operation for "
-             "the child named %s, needed to be immutable but was not. Either "
-             "the cap is being added to an immutable directory, or it was "
-             "originally retrieved from an immutable directory as an unknown "
-             "cap.") % quoted_name
-        return (t, http.BAD_REQUEST)
-    if isinstance(exc, MustBeReadonlyError):
-        quoted_name = quote_output(exc.args[1], encoding="utf-8")
-        t = ("MustBeReadonlyError: a cap passed to this operation for "
-             "the child named '%s', needed to be read-only but was not. "
-             "The cap is being passed in a read slot (ro_uri), or was retrieved "
-             "from a read slot as an unknown cap.") % quoted_name
-        return (t, http.BAD_REQUEST)
-    if isinstance(exc, blacklist.FileProhibited):
-        t = "Access Prohibited: %s" % quote_output(exc.reason, encoding="utf-8", quotemarks=False)
-        return (t, http.FORBIDDEN)
-    if isinstance(exc, WebError):
-        return (exc.text, exc.code)
-    if isinstance(exc, FileTooLargeError):
-        return ("FileTooLargeError: %s" % (exc,), http.REQUEST_ENTITY_TOO_LARGE)
-    return (str(exc), None)
-
 
 def humanize_failure(f):
     """
@@ -368,49 +261,6 @@ class NeedOperationHandleError(WebError):
     pass
 
 
-class SlotsSequenceElement(template.Element):
-    """
-    ``SlotsSequenceElement` is a minimal port of nevow's sequence renderer for
-    twisted.web.template.
-
-    Tags passed in to be templated will have two renderers available: ``item``
-    and ``tag``.
-    """
-
-    def __init__(self, tag, seq):
-        self.loader = template.TagLoader(tag)
-        self.seq = seq
-
-    @template.renderer
-    def header(self, request, tag):
-        return tag
-
-    @template.renderer
-    def item(self, request, tag):
-        """
-        A template renderer for each sequence item.
-
-        ``tag`` will be cloned for each item in the sequence provided, and its
-        slots filled from the sequence item. Each item must be dict-like enough
-        for ``tag.fillSlots(**item)``. Each cloned tag will be siblings with no
-        separator beween them.
-        """
-        for item in self.seq:
-            yield tag.clone(deep=False).fillSlots(**item)
-
-    @template.renderer
-    def empty(self, request, tag):
-        """
-        A template renderer for empty sequences.
-
-        This renderer will either return ``tag`` unmodified if the provided
-        sequence has no items, or return the empty string if there are any
-        items.
-        """
-        if len(self.seq) > 0:
-            return u''
-        else:
-            return tag
 
 
 class TokenOnlyWebApi(resource.Resource, object):
@@ -465,32 +315,3 @@ class TokenOnlyWebApi(resource.Resource, object):
         else:
             raise WebError("'%s' invalid type for 't' arg" % (t,), http.BAD_REQUEST)
 
-
-def exception_to_child(f):
-    """
-    Decorate ``getChild`` method with exception handling behavior to render an
-    error page reflecting the exception.
-    """
-    @wraps(f)
-    def g(self, name, req):
-        try:
-            return f(self, name, req)
-        except Exception as e:
-            description, status = humanize_exception(e)
-            return resource.ErrorPage(status, "Error", description)
-    return g
-
-
-def render_exception(f):
-    """
-    Decorate a ``render_*`` method with exception handling behavior to render
-    an error page reflecting the exception.
-    """
-    @wraps(f)
-    def g(self, request):
-        try:
-            return f(self, request)
-        except Exception as e:
-            description, status = humanize_exception(e)
-            return resource.ErrorPage(status, "Error", description).render(request)
-    return g

src/allmydata/web/common_py3.py

@@ -6,15 +6,32 @@ Can eventually be merged back into allmydata.web.common.
 
 from future.utils import PY2
 
+from functools import wraps
+
 if PY2:
     from nevow.inevow import IRequest as INevowRequest
 else:
     INevowRequest = None
 
-from twisted.web import resource, http
+from twisted.web import resource, http, template
+from twisted.web.template import tags as T
 from twisted.web.iweb import IRequest
 
+from allmydata import blacklist
+from allmydata.interfaces import (
+    EmptyPathnameComponentError,
+    ExistingChildError,
+    FileTooLargeError,
+    MustBeDeepImmutableError,
+    MustBeReadonlyError,
+    MustNotBeUnknownRWError,
+    NoSharesError,
+    NoSuchChildError,
+    NotEnoughSharesError,
+)
+from allmydata.mutable.common import UnrecoverableFileError
 from allmydata.util import abbreviate
+from allmydata.util.encodingutil import quote_output
 
 
 class WebError(Exception):
@@ -120,3 +137,210 @@ def abbreviate_time(data):
     if s >= 0.001:
         return "%.1fms" % (1000*s)
     return "%.0fus" % (1000000*s)
+
+
+def render_exception(f):
+    """
+    Decorate a ``render_*`` method with exception handling behavior to render
+    an error page reflecting the exception.
+    """
+    @wraps(f)
+    def g(self, request):
+        try:
+            return f(self, request)
+        except Exception as e:
+            description, status = humanize_exception(e)
+            return resource.ErrorPage(status, "Error", description).render(request)
+    return g
+
+
+class SlotsSequenceElement(template.Element):
+    """
+    ``SlotsSequenceElement` is a minimal port of nevow's sequence renderer for
+    twisted.web.template.
+
+    Tags passed in to be templated will have two renderers available: ``item``
+    and ``tag``.
+    """
+
+    def __init__(self, tag, seq):
+        self.loader = template.TagLoader(tag)
+        self.seq = seq
+
+    @template.renderer
+    def header(self, request, tag):
+        return tag
+
+    @template.renderer
+    def item(self, request, tag):
+        """
+        A template renderer for each sequence item.
+
+        ``tag`` will be cloned for each item in the sequence provided, and its
+        slots filled from the sequence item. Each item must be dict-like enough
+        for ``tag.fillSlots(**item)``. Each cloned tag will be siblings with no
+        separator beween them.
+        """
+        for item in self.seq:
+            yield tag.clone(deep=False).fillSlots(**item)
+
+    @template.renderer
+    def empty(self, request, tag):
+        """
+        A template renderer for empty sequences.
+
+        This renderer will either return ``tag`` unmodified if the provided
+        sequence has no items, or return the empty string if there are any
+        items.
+        """
+        if len(self.seq) > 0:
+            return u''
+        else:
+            return tag
+
+
+def humanize_exception(exc):
+    """
+    Like ``humanize_failure`` but for an exception.
+
+    :param Exception exc: The exception to describe.
+
+    :return: See ``humanize_failure``.
+    """
+    if isinstance(exc, EmptyPathnameComponentError):
+        return ("The webapi does not allow empty pathname components, "
+                "i.e. a double slash", http.BAD_REQUEST)
+    if isinstance(exc, ExistingChildError):
+        return ("There was already a child by that name, and you asked me "
+                "to not replace it.", http.CONFLICT)
+    if isinstance(exc, NoSuchChildError):
+        quoted_name = quote_output(exc.args[0], encoding="utf-8", quotemarks=False)
+        return ("No such child: %s" % quoted_name, http.NOT_FOUND)
+    if isinstance(exc, NotEnoughSharesError):
+        t = ("NotEnoughSharesError: This indicates that some "
+             "servers were unavailable, or that shares have been "
+             "lost to server departure, hard drive failure, or disk "
+             "corruption. You should perform a filecheck on "
+             "this object to learn more.\n\nThe full error message is:\n"
+             "%s") % str(exc)
+        return (t, http.GONE)
+    if isinstance(exc, NoSharesError):
+        t = ("NoSharesError: no shares could be found. "
+             "Zero shares usually indicates a corrupt URI, or that "
+             "no servers were connected, but it might also indicate "
+             "severe corruption. You should perform a filecheck on "
+             "this object to learn more.\n\nThe full error message is:\n"
+             "%s") % str(exc)
+        return (t, http.GONE)
+    if isinstance(exc, UnrecoverableFileError):
+        t = ("UnrecoverableFileError: the directory (or mutable file) could "
+             "not be retrieved, because there were insufficient good shares. "
+             "This might indicate that no servers were connected, "
+             "insufficient servers were connected, the URI was corrupt, or "
+             "that shares have been lost due to server departure, hard drive "
+             "failure, or disk corruption. You should perform a filecheck on "
+             "this object to learn more.")
+        return (t, http.GONE)
+    if isinstance(exc, MustNotBeUnknownRWError):
+        quoted_name = quote_output(exc.args[1], encoding="utf-8")
+        immutable = exc.args[2]
+        if immutable:
+            t = ("MustNotBeUnknownRWError: an operation to add a child named "
+                 "%s to a directory was given an unknown cap in a write slot.\n"
+                 "If the cap is actually an immutable readcap, then using a "
+                 "webapi server that supports a later version of Tahoe may help.\n\n"
+                 "If you are using the webapi directly, then specifying an immutable "
+                 "readcap in the read slot (ro_uri) of the JSON PROPDICT, and "
+                 "omitting the write slot (rw_uri), would also work in this "
+                 "case.") % quoted_name
+        else:
+            t = ("MustNotBeUnknownRWError: an operation to add a child named "
+                 "%s to a directory was given an unknown cap in a write slot.\n"
+                 "Using a webapi server that supports a later version of Tahoe "
+                 "may help.\n\n"
+                 "If you are using the webapi directly, specifying a readcap in "
+                 "the read slot (ro_uri) of the JSON PROPDICT, as well as a "
+                 "writecap in the write slot if desired, would also work in this "
+                 "case.") % quoted_name
+        return (t, http.BAD_REQUEST)
+    if isinstance(exc, MustBeDeepImmutableError):
+        quoted_name = quote_output(exc.args[1], encoding="utf-8")
+        t = ("MustBeDeepImmutableError: a cap passed to this operation for "
+             "the child named %s, needed to be immutable but was not. Either "
+             "the cap is being added to an immutable directory, or it was "
+             "originally retrieved from an immutable directory as an unknown "
+             "cap.") % quoted_name
+        return (t, http.BAD_REQUEST)
+    if isinstance(exc, MustBeReadonlyError):
+        quoted_name = quote_output(exc.args[1], encoding="utf-8")
+        t = ("MustBeReadonlyError: a cap passed to this operation for "
+             "the child named '%s', needed to be read-only but was not. "
+             "The cap is being passed in a read slot (ro_uri), or was retrieved "
+             "from a read slot as an unknown cap.") % quoted_name
+        return (t, http.BAD_REQUEST)
+    if isinstance(exc, blacklist.FileProhibited):
+        t = "Access Prohibited: %s" % quote_output(exc.reason, encoding="utf-8", quotemarks=False)
+        return (t, http.FORBIDDEN)
+    if isinstance(exc, WebError):
+        return (exc.text, exc.code)
+    if isinstance(exc, FileTooLargeError):
+        return ("FileTooLargeError: %s" % (exc,), http.REQUEST_ENTITY_TOO_LARGE)
+    return (str(exc), None)
+
+
+def get_root(ctx_or_req):
+    if PY2:
+        req = INevowRequest(ctx_or_req)
+    else:
+        req = IRequest(ctx_or_req)
+    depth = len(req.prepath) + len(req.postpath)
+    link = "/".join([".."] * depth)
+    return link
+
+
+class ReloadMixin(object):
+    REFRESH_TIME = 1*60
+
+    @template.renderer
+    def refresh(self, req, tag):
+        if self.monitor.is_finished():
+            return ""
+        # dreid suggests ctx.tag(**dict([("http-equiv", "refresh")]))
+        # but I can't tell if he's joking or not
+        tag.attributes["http-equiv"] = "refresh"
+        tag.attributes["content"] = str(self.REFRESH_TIME)
+        return tag
+
+    @template.renderer
+    def reload(self, req, tag):
+        if self.monitor.is_finished():
+            return ""
+        # url.gethere would break a proxy, so the correct thing to do is
+        # req.path[-1] + queryargs
+        ophandle = req.prepath[-1]
+        reload_target = ophandle + "?output=html"
+        cancel_target = ophandle + "?t=cancel"
+        cancel_button = T.form(T.input(type="submit", value="Cancel"),
+                               action=cancel_target,
+                               method="POST",
+                               enctype="multipart/form-data",)
+
+        return (T.h2("Operation still running: ",
+                     T.a("Reload", href=reload_target),
+                     ),
+                cancel_button,)
+
+
+def exception_to_child(f):
+    """
+    Decorate ``getChild`` method with exception handling behavior to render an
+    error page reflecting the exception.
+    """
+    @wraps(f)
+    def g(self, name, req):
+        try:
+            return f(self, name, req)
+        except Exception as e:
+            description, status = humanize_exception(e)
+            return resource.ErrorPage(status, "Error", description)
+    return g

src/allmydata/web/operations.py

@@ -20,6 +20,11 @@ from allmydata.web.common import (
     exception_to_child,
 )
 
+# Originally part of this module, so still part of its API:
+from .common_py3 import (  # noqa: F401
+    ReloadMixin,
+)
+
 MINUTE = 60
 HOUR = 60*MINUTE
 DAY = 24*HOUR
@@ -142,36 +147,3 @@ class OphandleTable(resource.Resource, service.Service):
             self.timers[ophandle].cancel()
         self.timers.pop(ophandle, None)
         self.handles.pop(ophandle, None)
-
-
-class ReloadMixin(object):
-    REFRESH_TIME = 1*MINUTE
-
-    @renderer
-    def refresh(self, req, tag):
-        if self.monitor.is_finished():
-            return ""
-        # dreid suggests ctx.tag(**dict([("http-equiv", "refresh")]))
-        # but I can't tell if he's joking or not
-        tag.attributes["http-equiv"] = "refresh"
-        tag.attributes["content"] = str(self.REFRESH_TIME)
-        return tag
-
-    @renderer
-    def reload(self, req, tag):
-        if self.monitor.is_finished():
-            return ""
-        # url.gethere would break a proxy, so the correct thing to do is
-        # req.path[-1] + queryargs
-        ophandle = req.prepath[-1]
-        reload_target = ophandle + "?output=html"
-        cancel_target = ophandle + "?t=cancel"
-        cancel_button = T.form(T.input(type="submit", value="Cancel"),
-                               action=cancel_target,
-                               method="POST",
-                               enctype="multipart/form-data",)
-
-        return (T.h2("Operation still running: ",
-                     T.a("Reload", href=reload_target),
-                     ),
-                cancel_button,)