Findit] Flake Checker: Pipeline to trigger try jobs to identify flake culprits

appengine/findit/model/flake/master_flake_analysis.py

Index: appengine/findit/model/flake/master_flake_analysis.py
diff --git a/appengine/findit/model/flake/master_flake_analysis.py b/appengine/findit/model/flake/master_flake_analysis.py
index 9add50b113071c2c6791adc03e3efcdd80273215..8d8149d88212eb5ed4a3009f2e512f927df11465 100644
--- a/appengine/findit/model/flake/master_flake_analysis.py
+++ b/appengine/findit/model/flake/master_flake_analysis.py
@@ -17,15 +17,74 @@ from model.flake.flake_swarming_task import FlakeSwarmingTaskData
 
 
 class DataPoint(ndb.Model):
+  # The build number corresponding to this data point. Only relevant if this
+  # data point is generated as the result of a flake swarming task.
   build_number = ndb.IntegerProperty(indexed=False)
+
+  # The pass rate of the test when run against this commit.
   pass_rate = ndb.FloatProperty(indexed=False)
+
+  # The ID of the swarming task responsible for generating this data.
   task_id = ndb.StringProperty(indexed=False)
+
+  # The git position of this data point.
   commit_position = ndb.IntegerProperty(indexed=False)
+
+  # The git hash of this data point.
   git_hash = ndb.StringProperty(indexed=False)
+
+  # The commit position of the build preceding this one. Only relevant if this
+  # data point is generated as the result of a flake swarming taask.
   previous_build_commit_position = ndb.IntegerProperty(indexed=False)
+
+  # The git hash of the data point 1 build before this one. Only relevant if
+  # this data point is generated as the result of a flake swarming task.
   previous_build_git_hash = ndb.StringProperty(indexed=False)
+
+  # The list of revisions between this build and the previous build. Only
+  # relevant if this data point is generated as the result of a flake swarming
+  # task.
   blame_list = ndb.StringProperty(repeated=True)
 
+  # The ID of the try job that generated this data point, if any.
+  try_job_id = ndb.StringProperty(indexed=False)
+
+  # The URL to the try job that generated this data point, if any.
+  try_job_url = ndb.StringProperty(indexed=False)
+
+  def GetCommitPosition(self, revision):
+    """Gets the commit position of a revision within blame_list.
+
+      It should be noted that commit position isn't guaranteed to be reliable
+      (monotonically increasing by increments of 1) 100% of the time. Should

[stgao, 2017/01/12 08:04:16]

Per my meeting with Robbie, commit position is reliable. So we could remove this
as we discussed in person.

[lijeffrey, 2017/01/12 09:52:52]

Done.

+      this be the case, commit position should not be used.
+
+    Args:
+      revision (str): The revision to search for.
+
+    Returns:
+      commit_position (int): The calculated commit position of revision.
+    """
+    assert revision in self.blame_list
+
+    for i in range(0, len(self.blame_list)):  # pragma: no branch
+      if revision == self.blame_list[i]:
+        return self.commit_position - i
+
+  def GetRevisionAtCommitPosition(self, commit_position):
+    """Gets the corresponding revision to commit_position.
+
+    Args:
+      commit_position (int): The commit position for which to find the
+          corresponding revision within self.blame_list.
+
+    Returns:
+      revision (str): The git revision corresponding to commit_position.
+    """
+    assert (commit_position > self.commit_position - len(self.blame_list) and
+            commit_position <= self.commit_position)
+    return self.blame_list[self.commit_position - commit_position]
+
 
 class MasterFlakeAnalysis(
     BaseAnalysis, BaseBuildModel, VersionedModel, TriagedModel):