Refactor the devserver to make it easier to control caching

chrome/common/extensions/docs/server2/path_canonicalizer.py

+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import logging
+import os
+from third_party.json_schema_compiler.model import UnixName
+import svn_constants
+
+class PathCanonicalizer(object):
+  '''Transforms paths into their canonical forms. Since the dev server has had
+  many incarnations - e.g. there didn't use to be apps/ - there may be old
+  paths lying around the webs. We try to redirect those to where they are now.
+  '''
+  def __init__(self, channel, compiled_fs_factory):
+    self._channel = channel
+    self._identity_fs = compiled_fs_factory.GetOrCreateIdentity()
+
+  def Canonicalize(self, path):
+    if any(path.startswith(prefix)
+           for prefix in ('extensions/', 'apps/', 'static/')):
+      return path
+
+    if '/' in path or path == '404.html':
+      return path
+
+    public_template_path = svn_constants.PUBLIC_TEMPLATE_PATH
+    apps_templates = self._identity_fs.GetFromFileListing(
+        '/'.join((public_template_path, 'apps')))

[cduvall, 2013/04/08 07:09:24]

extra parens?

[not at google - send to devlin, 2013/04/08 12:21:21]

Yeah, python (well, string.join) being annoying. Need to force the first
argument to be a tuple so need to double-paren it.

+    extensions_templates = self._identity_fs.GetFromFileListing(
+        '/'.join((public_template_path, 'extensions')))

[cduvall, 2013/04/08 07:09:24]

same

[not at google - send to devlin, 2013/04/08 12:21:21]

Likewise.

+
+    if self._channel is None:
+      apps_path = '/apps/%s' % path
+      extensions_path = '/extensions/%s' % path
+    else:
+      apps_path = '/%s/apps/%s' % (self._channel, path)
+      extensions_path = '/%s/extensions/%s' % (self._channel, path)
+
+    unix_path = UnixName(os.path.splitext(path)[0])
+    if unix_path in extensions_templates:

[cduvall, 2013/04/08 07:09:24]

should these be checking '%s.html' % unix_path ? Or do the paths in
extension_templates not have the .html?

[not at google - send to devlin, 2013/04/08 12:21:21]

It has an os.path.splitext which strips the html -

Though I didn't see it either, so wrote a bunch of tests, and found a bug (in
the original code I think) - so yay!

+      return extensions_path
+    if unix_path in apps_templates:
+      return app_path
+    return extensions_path