[Findit] Flake Checker: Extract commit position and git hash and display to UI for each analyzed bu…

appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py

Index: appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py
diff --git a/appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py b/appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py
index f9e7925cb5a89e59f81669cab5c4b397dc1e26db..5d81cbbe1d10406b3813b4ac27c425176e8ab6ba 100644
--- a/appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py
+++ b/appengine/findit/waterfall/process_flake_swarming_task_result_pipeline.py
@@ -7,10 +7,38 @@ import logging
 from model.flake.flake_swarming_task import FlakeSwarmingTask
 from model.flake.master_flake_analysis import DataPoint
 from model.flake.master_flake_analysis import MasterFlakeAnalysis
+from waterfall import build_util
+from waterfall import buildbot
 from waterfall.process_base_swarming_task_result_pipeline import (
     ProcessBaseSwarmingTaskResultPipeline)
 
 
+def _GetCommitPositionAndGitHash(master_name, builder_name, build_number):
+  """Gets the commit position and git hash of a build.
+
+  Args:
+    master_name (str): The name of the master.
+    builder_name (str): The name of the builder.
+    build_number (int): The build number.
+
+  Returns:
+    commit_position (int), git_hash (str): The git commit position corresponding
+      to the last commit in the build, and the git hash itself.
+  """
+  if build_number < 0:
+    return None, None
+
+  build = build_util.DownloadBuildData(master_name, builder_name, build_number)
+
+  if not build.data:
+    return None, None
+
+  build_info = buildbot.ExtractBuildInfo(
+      master_name, builder_name, build_number, build.data)
+
+  return build_info.commit_position, build_info.chromium_revision
+
+
 class ProcessFlakeSwarmingTaskResultPipeline(
     ProcessBaseSwarmingTaskResultPipeline):
   """A pipeline for monitoring swarming task and processing task result.
@@ -75,6 +103,19 @@ class ProcessFlakeSwarmingTaskResultPipeline(
     data_point.build_number = build_number
     data_point.pass_rate = pass_rate
     data_point.task_id = flake_swarming_task.task_id
+
+    # Include git commit position information about each build that was run.
+    if build_number > 0:
+      previous_commit, previous_build_git_hash = _GetCommitPositionAndGitHash(
+          master_name, builder_name, build_number - 1)
+      data_point.previous_build_commit_position = previous_commit
+      data_point.previous_build_git_hash = previous_build_git_hash
+
+    commit_position, git_hash = _GetCommitPositionAndGitHash(
+        master_name, builder_name, build_number)
+    data_point.commit_position = commit_position
+    data_point.git_hash = git_hash
+
     master_flake_analysis.data_points.append(data_point)
 
     results = flake_swarming_task.GetFlakeSwarmingTaskData()
@@ -100,4 +141,4 @@ class ProcessFlakeSwarmingTaskResultPipeline(
                        step_name, master_build_number, test_name, _):
     # Gets the appropriate kind of swarming task (FlakeSwarmingTask).
     return FlakeSwarmingTask.Get(master_name, builder_name, build_number,
-                                 step_name, test_name)
+                                 step_name, test_name)