Extensions Docs Server: Internal file system

chrome/common/extensions/docs/server2/async_fetch_value.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.
+
+import xml.dom.minidom as xml
+
+class AsyncFetchValue(object):

[not at google - send to devlin, 2012/07/18 10:39:15]

Hm, sorry, this is pretty tied into the FileSystem stuff. Specifically
SubversionFileSystem. Could you move it into there? And... err, rename it
_AsyncFetchFuture.

[cduvall, 2012/07/18 21:26:10]

Done.

+  def __init__(self, paths, fetcher):
+    self._fetches = []
+    self._value = {}
+    self._error = None
+    for path in paths:
+      rpc = fetcher.create_rpc()
+      if path.endswith('/'):
+        rpc.callback = self._MakeCallback(self._ListDir, rpc, path)
+      else:
+        rpc.callback = self._MakeCallback(lambda file_: file_, rpc, path)
+      fetcher.make_fetch_call(rpc, path)
+      self._fetches.append(rpc)
+
+  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
+
+  def _MakeCallback(self, f, rpc, path):
+    return lambda: self._Callback(rpc, path, f)
+
+  def _Callback(self, rpc, key, f):
+    result = rpc.get_result()
+    self._value[key] = f(result.content)
+
+  def Get(self):
+    for fetch in self._fetches:
+      fetch.wait()
+    if self._error is not None:

[not at google - send to devlin, 2012/07/18 10:39:15]

what's wrong with !=

[cduvall, 2012/07/18 21:26:10]

From PEP 8: "Comparisons to singletons like None should always be done with is
or is not, never the equality operators."

[not at google - send to devlin, 2012/07/19 03:55:18]

wtf python. "is not" is an operator? That could equally be read as

if self._error is (not None):

which is clearly none. Except apparnetly Python has the world's strangest
operator. They shoud have made it "isnt", they have "elif", why not...

kinda kidding. but also kinda not.

</rant>

or maybe that should be

{{/rant}}

[cduvall, 2012/07/19 17:18:28]

haha {{/rant}}

+      raise self._error
+    return self._value
+