Add a preliminary Python API for retrieving Google API keys.

google_apis/google_api_keys.py

+#!/usr/bin/env python
+# 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.
+
+"""Python API for retrieving API keys.
+
+Note that this cannot have the exact same semantics (at the moment) as
+the C++ API in google_api_keys.h, since it does not have access to gyp
+variables or preprocessor defines.
+
+TODO(joi): Give this have the same semantics as the C++ API.
+"""
+
+import os
+import re
+import sys
+
+
+def _GetTokenFromOfficialFile(token_name):
+  """Parses the token from the official file if it exists, else returns None."""
+  official_path = os.path.join(sys.path[0],
+                               'internal/google_chrome_api_keys.h')
+  if not os.path.isfile(official_path):
+    return None
+
+  line_regexp = '^#define\s*%s\s*"([^"]+)"\s*$' % token_name

[Jamie, 2012/09/17 22:58:05]

FYI (I don't think it matters), but if the string has an embedded quote encoded
as \" then this regex would fail. My previous suggestion about failing the build
if the line is not formatted expected could probably cover this case as well.

[Jói, 2012/09/17 23:21:52]

Fixed.

+  line_pattern = re.compile(line_regexp)
+  def ParseLine(current_line):
+    result = line_pattern.match(current_line)
+    if result:
+      return result.group(1)
+    else:
+      return None
+
+  with open(official_path) as f:
+    current_line = ''
+    for line in f:
+      line = line.strip()
+      if line.endswith('\\'):
+        current_line += line[:-1]
+      elif current_line:
+        # Last line in multi-line #define, time to parse it.
+        # TODO(joi): Handle combining multi-line quoted strings.
+        current_line += line
+        token = ParseLine(current_line)
+        current_line = ''
+      else:
+        current_line = line
+        token = ParseLine(current_line)
+        current_line = ''
+      if token:
+        return token
+    return None
+
+
+def _GetToken(token_name):
+  """Returns the API token with the given name, or dummytoken by default."""
+  if token_name in os.environ:
+    return os.environ[token_name]
+

[Jamie, 2012/09/17 22:58:05]

Nit: I don't think this blank line adds to readability.

[Jói, 2012/09/17 23:21:52]

Done.

+  token = _GetTokenFromOfficialFile(token_name)
+  if token:
+    return token
+  else:
+    return 'dummytoken'

[Jamie, 2012/09/17 23:06:41]

Could this string be exposed via a constant so that users of this module could
detect failure without needing to duplicate it?

[Jói, 2012/09/17 23:21:52]

Done.

+
+
+def GetAPIKey():
+  """Returns the simple API key."""
+  return _GetToken('GOOGLE_API_KEY')
+
+
+def GetClientID(client_name):
+  """Returns the OAuth 2.0 client ID for the client of the given name."""
+  return _GetToken('GOOGLE_CLIENT_ID_%s' % client_name)
+
+
+def GetClientSecret(client_name):
+  """Returns the OAuth 2.0 client secret for the client of the given name."""
+  return _GetToken('GOOGLE_CLIENT_SECRET_%s' % client_name)
+
+
+if __name__ == "__main__":
+  print 'GOOGLE_API_KEY=%s' % GetAPIKey()
+  print 'GOOGLE_CLIENT_ID_MAIN=%s' % GetClientID('MAIN')
+  print 'GOOGLE_CLIENT_SECRET_MAIN=%s' % GetClientSecret('MAIN')
+  print 'GOOGLE_CLIENT_ID_CLOUD_PRINT=%s' % GetClientID('CLOUD_PRINT')
+  print 'GOOGLE_CLIENT_SECRET_CLOUD_PRINT=%s' % GetClientSecret('CLOUD_PRINT')
+  print 'GOOGLE_CLIENT_ID_REMOTING=%s' % GetClientID('REMOTING')
+  print 'GOOGLE_CLIENT_SECRET_REMOTING=%s' % GetClientSecret('REMOTING')