Docserver: refactor Servlet, ObjectStore, and ServerInstance architecture to

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

 # Copyright (c) 2012 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.
 
-from file_system import FileSystem, FileNotFoundError, StatInfo, ToUnicode
-from future import Future
 import logging
 import re
 import posixpath
 import xml.dom.minidom as xml
 from xml.parsers.expat import ExpatError
 
+from appengine_url_fetcher import AppEngineUrlFetcher
+from docs_server_utils import StringIdentity
+from file_system import FileSystem, FileNotFoundError, StatInfo, ToUnicode
+from future import Future
+import svn_constants
+import url_constants
+
 class _AsyncFetchFuture(object):
   def __init__(self, paths, fetcher, binary):
     # A list of tuples of the form (path, Future).
-    self._fetches = [(path, fetcher.FetchAsync(path)) for path in paths]
+    self._fetches = [(path, fetcher.FetchAsync(path))
+                     for path in paths]
     self._value = {}
     self._error = None
     self._binary = binary
 
   def _ListDir(self, directory):
     dom = xml.parseString(directory)
     files = [elem.childNodes[0].data for elem in dom.getElementsByTagName('a')]
     if '..' in files:
       files.remove('..')
     return files
@@ skipping 11 matching lines @@
         self._value[path] = self._ListDir(result.content)
       elif not self._binary:
         self._value[path] = ToUnicode(result.content)
       else:
         self._value[path] = result.content
     if self._error is not None:
       raise self._error
     return self._value
 
 class SubversionFileSystem(FileSystem):
-  """Class to fetch resources from src.chromium.org.
-  """
-  def __init__(self, fetcher, stat_fetcher):
-    self._fetcher = fetcher
+  '''Class to fetch resources from src.chromium.org.
+  '''
+  @staticmethod
+  def Create(branch):
+    if branch == 'trunk':
+      svn_path = 'trunk/src/%s' % svn_constants.EXTENSIONS_PATH
+    else:
+      svn_path = 'branches/%s/src/%s' % (branch,
+                                         svn_constants.EXTENSIONS_PATH)
+    return SubversionFileSystem(
+        AppEngineUrlFetcher('%s/%s' % (url_constants.SVN_URL, svn_path)),
+        AppEngineUrlFetcher('%s/%s' % (url_constants.VIEWVC_URL, svn_path)),
+        svn_path)
+
+  def __init__(self, file_fetcher, stat_fetcher, svn_path):
+    self._file_fetcher = file_fetcher
     self._stat_fetcher = stat_fetcher
+    self._svn_path = svn_path
 
   def Read(self, paths, binary=False):
-    return Future(delegate=_AsyncFetchFuture(paths, self._fetcher, binary))
+    return Future(delegate=_AsyncFetchFuture(paths,
+                                             self._file_fetcher,
+                                             binary))
 
   def _ParseHTML(self, html):
-    """Unfortunately, the viewvc page has a stray </div> tag, so this takes care
+    '''Unfortunately, the viewvc page has a stray </div> tag, so this takes care
     of all mismatched tags.
-    """
+    '''
     try:
       return xml.parseString(html)
     except ExpatError as e:
       return self._ParseHTML('\n'.join(
           line for (i, line) in enumerate(html.split('\n'))
           if e.lineno != i + 1))
 
   def _CreateStatInfo(self, html):
     def inner_text(node):
       '''Like node.innerText in JS DOM, but strips surrounding whitespace.
@@ skipping 42 matching lines @@
       return StatInfo(str(parent_version),
                       dict((path, str(version))
                            for path, version in child_versions.iteritems()))
 
     # Bleh, but, this data is so unreliable. There are actually some empty file
     # listings caused by git/svn/something not cleaning up empty dirs.
     return StatInfo('0', {})
 
   def Stat(self, path):
     directory, filename = posixpath.split(path)
-    result = self._stat_fetcher.Fetch(directory + '/')
+    directory += '/'
+    result = self._stat_fetcher.Fetch(directory)
     if result.status_code == 404:
       raise FileNotFoundError(
           'Got 404 when fetching %s from %s for Stat' % (path, directory))
     stat_info = self._CreateStatInfo(result.content)
     if path.endswith('/'):
       return stat_info
     if filename not in stat_info.child_versions:
       raise FileNotFoundError('%s was not in child versions' % filename)
     return StatInfo(stat_info.child_versions[filename])
+
+  def GetIdentity(self):
+    return '@'.join((self.__class__.__name__, StringIdentity(self._svn_path)))