Docserver: Add support for viewing docs with a codereview patch applied

chrome/common/extensions/docs/server2/patch_servlet.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 json
+
+from appengine_url_fetcher import AppEngineUrlFetcher
+from appengine_wrappers import GetAppVersion
+from object_store_creator import ObjectStoreCreator
+#from servlet import Servlet
+import svn_constants
+import url_constants
+
+PATCH_BASEURL = '_patch/'
+PATCH_CHANNEL_NAME = 'trunk'
+CHROMIUM_REPO_BASEURLS = [
+  'https://src.chromium.org/svn/trunk/src/',
+  'http://src.chromium.org/svn/trunk/src/',
+  'svn://svn.chromium.org/chrome/trunk/src',
+  'https://chromium.googlesource.com/chromium/src.git@master',
+  'http://git.chromium.org/chromium/src.git@master',
+]
+DOCS_PATHS = [
+  svn_constants.API_PATH,
+  svn_constants.INTRO_PATH,
+  svn_constants.ARTICLE_PATH,
+  svn_constants.PUBLIC_TEMPLATE_PATH,
+  svn_constants.PRIVATE_TEMPLATE_PATH,
+  svn_constants.JSON_PATH,
+  svn_constants.STATIC_PATH
+]
+RIETVELD_ISSUE_JSON = 'api/%s'
+RIETVELD_PATCHSET_JSON = 'api/%s/%s'
+
+class PatchData(object):
+  _object_store = None
+
+  def __init__(self, issue, patchset, files):
+    self.issue = issue
+    self.patchset = patchset
+    self.files = files
+
+  @staticmethod
+  def Create(issue):
+    fetcher = AppEngineUrlFetcher(url_constants.CODEREVIEW_SERVER)
+    object_store = PatchData._GetOrCreateObjectStore()
+    patchset = PatchData._GetPatchsetFromIssue(issue, fetcher, object_store)
+    if patchset is None:
+      return None
+    files = PatchData._GetPatchsetFiles(issue, patchset, fetcher, object_store)
+    if len(files) == 0:
+      return None
+    return PatchData(issue, patchset, files)
+
+  @staticmethod
+  def _GetPatchsetFromIssue(issue, fetcher, object_store):
+    patchset = object_store.Get(issue).Get()
+    if patchset is not None:
+      return patchset
+
+    try:
+      issue_json = json.loads(fetcher.Fetch(
+          RIETVELD_ISSUE_JSON % issue).content)
+    except Exception as e:
+      return None
+
+    if issue_json.get('closed'):
+      return None
+
+    patchsets = issue_json.get('patchsets')
+    if not isinstance(patchsets, list) or len(patchsets) == 0:
+      return None
+
+    if not issue_json.get('base_url') in CHROMIUM_REPO_BASEURLS:
+      return None
+
+    patchset = patchsets[-1]
+    object_store.Set(issue, patchset)
+    return patchset
+
+  @staticmethod
+  def _GetPatchsetFiles(issue, patchset, fetcher, object_store):
+    key = '%s.%s' % (issue, patchset)
+    docs_files = object_store.Get(key).Get()
+    if docs_files is not None:
+      return docs_files
+
+    try:
+      patchset_json = json.loads(fetcher.Fetch(
+          RIETVELD_PATCHSET_JSON % (issue, patchset)).content)
+    except Exception as e:
+      return []
+
+    files = patchset_json.get('files')
+    if files is None or not isinstance(files, dict):
+      return []
+
+    docs_files = []
+    for f in files:
+      f = f.split(svn_constants.EXTENSIONS_PATH + '/', 1)[1]
+      if (f.startswith(svn_constants.DOCS_PATH) or
+          f.startswith(svn_constants.API_PATH)):
+        docs_files.append(f)
+    if len(docs_files) == 0:
+      return []
+
+    object_store.Set(key, docs_files)
+    return docs_files
+
+  @staticmethod
+  def _GetOrCreateObjectStore():
+    if PatchData._object_store is None:
+      PatchData._object_store = (ObjectStoreCreator.SharedFactory(
+          GetAppVersion()).Create(PatchData).Create())
+    return PatchData._object_store
+
+class PatchServlet(object):
+  '''Servlet which renders patched docs.
+  '''
+  @staticmethod
+  def SplitPatchFromPath(path):
+    if path.startswith(PATCH_BASEURL):
+      remaining_path = path.split(PATCH_BASEURL, 1)[1]
+      if not '/' in remaining_path:
+        return (None, None, None)
+      issue, real_path = remaining_path.split('/', 1)
+      if not issue.isdigit() or len(real_path) == 0:
+        return (None, None, None)
+      return (PATCH_CHANNEL_NAME, issue, real_path)
+    else:
+      return (None, None, None)