Don't submit the CL in roll_deps if the revision diff is too small

For example, --cq-over=100 means that "Roll chromium_revision
(524047:524105)" would not be submitted because the revision
difference is below 100. The CL will still be uploaded and tested.

This will be used in the periodic run of the autoroller to prevent
committing too frequently but keep the test runs at the same rate,
as a rudimentary version of an FYI waterfall of DEPS rolls.

TBR=phoglund@webrtc.org

Bug: webrtc:8688
Change-Id: Ie46e154ddee390648d3d0c0fbb24ec93676bb275
No-Try: True
Reviewed-on: https://webrtc-review.googlesource.com/36320
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21454}

tools_webrtc/autoroller/roll_deps.py

@@ -403,13 +403,31 @@ def _LocalCommit(commit_msg, dry_run):
     _RunCommand(['git', 'commit', '-m', commit_msg])
 
 
-def _UploadCL(dry_run, skip_cq=False):
+def ShouldUseCQ(skip_cq, cq_over, current_cr_rev, new_cr_rev):
+  if skip_cq:
+    return 0
+  if (new_cr_rev - current_cr_rev) < cq_over:
+    return 1
+  return 2
+
+
+def _UploadCL(dry_run, commit_queue=2):
+  """Upload the committed changes as a changelist to Gerrit.
+
+  commit_queue:
+    - 2: Submit to commit queue.
+    - 1: Commit queue dry run.
+    - 0: Skip CQ, upload only.
+  """
   logging.info('Uploading CL...')
   if not dry_run:
     cmd = ['git', 'cl', 'upload', '-f', '--gerrit']
-    if not skip_cq:
+    if commit_queue >= 2:
       logging.info('Sending the CL to the CQ...')
       cmd.extend(['--use-commit-queue', '--send-mail'])
+    elif commit_queue >= 1:
+      logging.info('Starting CQ dry run...')
+      cmd.extend(['--cq-dry-run'])
     _RunCommand(cmd, extra_env={'EDITOR': 'true', 'SKIP_GCE_AUTH_FOR_GIT': '1'})
 
 
@@ -432,8 +450,12 @@ def main():
                  default=False,
                  help=('Ignore if the current branch is not master or if there '
                        'are uncommitted changes (default: %(default)s).'))
-  p.add_argument('--skip-cq', action='store_true', default=False,
-                 help='Skip sending the CL to the CQ (default: %(default)s)')
+  grp = p.add_mutually_exclusive_group()
+  grp.add_argument('--skip-cq', action='store_true', default=False,
+                   help='Skip sending the CL to the CQ (default: %(default)s)')
+  grp.add_argument('--cq-over', type=int, default=1,
+                   help=('Commit queue dry run if the revision difference '
+                         'is below this number (default: %(default)s)'))
   p.add_argument('-v', '--verbose', action='store_true', default=False,
                  help='Be extra verbose in printing of log messages.')
   opts = p.parse_args()
@@ -481,7 +503,9 @@ def main():
     logging.info("No DEPS changes detected, skipping CL creation.")
   else:
     _LocalCommit(commit_msg, opts.dry_run)
-    _UploadCL(opts.dry_run, opts.skip_cq)
+    commit_queue = ShouldUseCQ(opts.skip_cq, opts.cq_over,
+                               current_cr_rev, new_cr_rev)
+    _UploadCL(opts.dry_run, commit_queue)
   return 0
 
 

tools_webrtc/autoroller/unittests/roll_deps_test.py

@@ -20,7 +20,7 @@ PARENT_DIR = os.path.join(SCRIPT_DIR, os.pardir)
 sys.path.append(PARENT_DIR)
 import roll_deps
 from roll_deps import CalculateChangedDeps, GetMatchingDepsEntries, \
-  ParseDepsDict, ParseLocalDepsFile, UpdateDepsFile
+  ParseDepsDict, ParseLocalDepsFile, UpdateDepsFile, ShouldUseCQ
 
 
 TEST_DATA_VARS = {
@@ -140,6 +140,17 @@ class TestRollChromiumRevision(unittest.TestCase):
     self.assertEquals(changed_deps[1].new_rev, BUILDTOOLS_NEW_REV)
 
 
+class TestShouldUseCQ(unittest.TestCase):
+  def testSkip(self):
+    self.assertEquals(ShouldUseCQ(True, 99, 500000, 500100), 0)
+
+  def testDryRun(self):
+    self.assertEquals(ShouldUseCQ(False, 101, 500000, 500100), 1)
+
+  def testSubmit(self):
+    self.assertEquals(ShouldUseCQ(False, 100, 500000, 500100), 2)
+
+
 def _SetupGitLsRemoteCall(cmd_fake, url, revision):
   cmd = ['git', 'ls-remote', url, revision]
   cmd_fake.AddExpectation(cmd, _returns=(revision, None))