test_storage_web now runnable on Python 3 (even if it doesn't pass).

src/allmydata/test/test_storage_web.py

@@ -18,7 +18,7 @@ from twisted.web.template import flattenString
 # We need to use `nevow.inevow.IRequest` for now for compatibility
 # with the code in web/common.py.  Once nevow bits are gone from
 # web/common.py, we can use `twisted.web.iweb.IRequest` here.
-from nevow.inevow import IRequest
+from twisted.web.iweb import IRequest
 
 from twisted.web.server import Request
 from twisted.web.test.requesthelper import DummyChannel
@@ -36,7 +36,7 @@ from allmydata.web.storage import (
     StorageStatusElement,
     remove_prefix
 )
-from .test_storage import FakeCanary
+from .common_py3 import FakeCanary
 
 def remove_tags(s):
     s = re.sub(r'<[^>]*>', ' ', s)

src/allmydata/web/common.py

@@ -15,11 +15,15 @@ from allmydata.interfaces import ExistingChildError, NoSuchChildError, \
      EmptyPathnameComponentError, MustBeDeepImmutableError, \
      MustBeReadonlyError, MustNotBeUnknownRWError, SDMF_VERSION, MDMF_VERSION
 from allmydata.mutable.common import UnrecoverableFileError
-from allmydata.util import abbreviate
 from allmydata.util.hashutil import timing_safe_compare
 from allmydata.util.time_format import format_time, format_delta
 from allmydata.util.encodingutil import to_str, quote_output
 
+# Originally part of this module, so still part of its API:
+from .common_py3 import (  # noqa: F401
+    get_arg, abbreviate_time, MultiFormatResource, WebError
+)
+
 
 def get_filenode_metadata(filenode):
     metadata = {'mutable': filenode.is_mutable()}
@@ -104,24 +108,6 @@ def get_root(ctx_or_req):
     link = "/".join([".."] * depth)
     return link
 
-def get_arg(ctx_or_req, argname, default=None, multiple=False):
-    """Extract an argument from either the query args (req.args) or the form
-    body fields (req.fields). If multiple=False, this returns a single value
-    (or the default, which defaults to None), and the query args take
-    precedence. If multiple=True, this returns a tuple of arguments (possibly
-    empty), starting with all those in the query args.
-    """
-    req = IRequest(ctx_or_req)
-    results = []
-    if argname in req.args:
-        results.extend(req.args[argname])
-    if req.fields and argname in req.fields:
-        results.append(req.fields[argname].value)
-    if multiple:
-        return tuple(results)
-    if results:
-        return results[0]
-    return default
 
 def convert_children_json(nodemaker, children_json):
     """I convert the JSON output of GET?t=json into the dict-of-nodes input
@@ -141,20 +127,6 @@ def convert_children_json(nodemaker, children_json):
             children[namex] = (childnode, metadata)
     return children
 
-def abbreviate_time(data):
-    # 1.23s, 790ms, 132us
-    if data is None:
-        return ""
-    s = float(data)
-    if s >= 10:
-        return abbreviate.abbreviate_time(data)
-    if s >= 1.0:
-        return "%.2fs" % s
-    if s >= 0.01:
-        return "%.0fms" % (1000*s)
-    if s >= 0.001:
-        return "%.1fms" % (1000*s)
-    return "%.0fus" % (1000000*s)
 
 def compute_rate(bytes, seconds):
     if bytes is None:
@@ -219,10 +191,6 @@ def render_time(t):
 def render_time_attr(t):
     return format_time(time.localtime(t))
 
-class WebError(Exception):
-    def __init__(self, text, code=http.BAD_REQUEST):
-        self.text = text
-        self.code = code
 
 # XXX: to make UnsupportedMethod return 501 NOT_IMPLEMENTED instead of 500
 # Internal Server Error, we either need to do that ICanHandleException trick,
@@ -421,62 +389,6 @@ class MultiFormatPage(Page):
             return lambda ctx: renderer(IRequest(ctx))
 
 
-class MultiFormatResource(resource.Resource, object):
-    """
-    ``MultiFormatResource`` is a ``resource.Resource`` that can be rendered in
-    a number of different formats.
-
-    Rendered format is controlled by a query argument (given by
-    ``self.formatArgument``).  Different resources may support different
-    formats but ``json`` is a pretty common one.  ``html`` is the default
-    format if nothing else is given as the ``formatDefault``.
-    """
-    formatArgument = "t"
-    formatDefault = None
-
-    def render(self, req):
-        """
-        Dispatch to a renderer for a particular format, as selected by a query
-        argument.
-
-        A renderer for the format given by the query argument matching
-        ``formatArgument`` will be selected and invoked.  render_HTML will be
-        used as a default if no format is selected (either by query arguments
-        or by ``formatDefault``).
-
-        :return: The result of the selected renderer.
-        """
-        t = get_arg(req, self.formatArgument, self.formatDefault)
-        renderer = self._get_renderer(t)
-        return renderer(req)
-
-    def _get_renderer(self, fmt):
-        """
-        Get the renderer for the indicated format.
-
-        :param str fmt: The format.  If a method with a prefix of ``render_``
-            and a suffix of this format (upper-cased) is found, it will be
-            used.
-
-        :return: A callable which takes a twisted.web Request and renders a
-            response.
-        """
-        renderer = None
-
-        if fmt is not None:
-            try:
-                renderer = getattr(self, "render_{}".format(fmt.upper()))
-            except AttributeError:
-                raise WebError(
-                    "Unknown {} value: {!r}".format(self.formatArgument, fmt),
-                )
-
-        if renderer is None:
-            renderer = self.render_HTML
-
-        return renderer
-
-
 class SlotsSequenceElement(template.Element):
     """
     ``SlotsSequenceElement` is a minimal port of nevow's sequence renderer for

src/allmydata/web/common_py3.py

@@ -0,0 +1,120 @@
+"""
+Common utilities that are available from Python 3.
+
+Can eventually be merged back into twisted.web.common.
+"""
+
+from future.utils import PY2
+
+if PY2:
+    from nevow.inevow import IRequest as INevowRequest
+else:
+    INevowRequest = None
+
+from twisted.web import resource, http
+from twisted.web.iweb import IRequest
+
+from allmydata.util import abbreviate
+
+
+class WebError(Exception):
+    def __init__(self, text, code=http.BAD_REQUEST):
+        self.text = text
+        self.code = code
+
+
+def get_arg(ctx_or_req, argname, default=None, multiple=False):
+    """Extract an argument from either the query args (req.args) or the form
+    body fields (req.fields). If multiple=False, this returns a single value
+    (or the default, which defaults to None), and the query args take
+    precedence. If multiple=True, this returns a tuple of arguments (possibly
+    empty), starting with all those in the query args.
+    """
+    results = []
+    if PY2:
+        req = INevowRequest(ctx_or_req)
+        if argname in req.args:
+            results.extend(req.args[argname])
+        if req.fields and argname in req.fields:
+            results.append(req.fields[argname].value)
+    else:
+        req = IRequest(ctx_or_req)
+        if argname in req.args:
+            results.extend(req.args[argname])
+    if multiple:
+        return tuple(results)
+    if results:
+        return results[0]
+    return default
+
+
+class MultiFormatResource(resource.Resource, object):
+    """
+    ``MultiFormatResource`` is a ``resource.Resource`` that can be rendered in
+    a number of different formats.
+
+    Rendered format is controlled by a query argument (given by
+    ``self.formatArgument``).  Different resources may support different
+    formats but ``json`` is a pretty common one.  ``html`` is the default
+    format if nothing else is given as the ``formatDefault``.
+    """
+    formatArgument = "t"
+    formatDefault = None
+
+    def render(self, req):
+        """
+        Dispatch to a renderer for a particular format, as selected by a query
+        argument.
+
+        A renderer for the format given by the query argument matching
+        ``formatArgument`` will be selected and invoked.  render_HTML will be
+        used as a default if no format is selected (either by query arguments
+        or by ``formatDefault``).
+
+        :return: The result of the selected renderer.
+        """
+        t = get_arg(req, self.formatArgument, self.formatDefault)
+        renderer = self._get_renderer(t)
+        return renderer(req)
+
+    def _get_renderer(self, fmt):
+        """
+        Get the renderer for the indicated format.
+
+        :param str fmt: The format.  If a method with a prefix of ``render_``
+            and a suffix of this format (upper-cased) is found, it will be
+            used.
+
+        :return: A callable which takes a twisted.web Request and renders a
+            response.
+        """
+        renderer = None
+
+        if fmt is not None:
+            try:
+                renderer = getattr(self, "render_{}".format(fmt.upper()))
+            except AttributeError:
+                raise WebError(
+                    "Unknown {} value: {!r}".format(self.formatArgument, fmt),
+                )
+
+        if renderer is None:
+            renderer = self.render_HTML
+
+        return renderer
+
+
+def abbreviate_time(data):
+    # 1.23s, 790ms, 132us
+    if data is None:
+        return ""
+    s = float(data)
+    if s >= 10:
+        return abbreviate.abbreviate_time(data)
+    if s >= 1.0:
+        return "%.2fs" % s
+    if s >= 0.01:
+        return "%.0fms" % (1000*s)
+    if s >= 0.001:
+        return "%.1fms" % (1000*s)
+    return "%.0fus" % (1000000*s)

src/allmydata/web/storage.py

@@ -8,7 +8,7 @@ from twisted.web.template import (
     renderer,
     renderElement
 )
-from allmydata.web.common import (
+from allmydata.web.common_py3 import (
     abbreviate_time,
     MultiFormatResource
 )