Set changeHorizon to put an upper-bound on database size, otherwise the database will never stop gr…

scripts/common/chromium_utils.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.
 
 """ Set of basic operations/utilities that are used by the build. """
 
 from contextlib import contextmanager
 import ast
 import base64
 import cStringIO
@@ skipping 1881 matching lines @@
       # scons build cruft
       '.sconsign.dblite',
       # build helper, not needed on testers
       'mksnapshot',
     ]
 
   return all_platforms
 
 
 def DatabaseSetup(buildmaster_config, require_dbconfig=False):
-  """Read database credentials in the master directory."""
+  """Configure the database settings for the buildbot master."""
+
+  # By default nothing is ever deleted from the database.  We set a
+  # changeHorizon here to put an upper bound on the database size.
+  if 'changeHorizon' not in buildmaster_config:
+    buildmaster_config['changeHorizon'] = 3000
+
+  # Read database credentials in the master directory.
   if os.path.isfile('.dbconfig'):
     values = {}
     execfile('.dbconfig', values)
     if 'password' not in values:
       raise Exception('could not get db password')
 
     buildmaster_config['db_url'] = 'postgresql://%s:%s@%s/%s' % (
         values['username'], values['password'],
         values.get('hostname', 'localhost'), values['dbname'])
   else:
@@ skipping 119 matching lines @@
     return False
   # Matches e.g. "cl_x86 = path/to/clang-cl.exe"
   clang_cl_re = re.compile(
       r'^cl_x\d\d\s+\=\s+(?P<compiler_path>[^ ]+)\s.*$',
       re.VERBOSE)
   for line in open(build_file):
     m = clang_cl_re.match(line)
     if m:
       return 'clang' in m.group('compiler_path')
   return False