Keep track of hashes triggered instead of builds.

scripts/slave/gatekeeper_ng_db.py

Index: scripts/slave/gatekeeper_ng_db.py
diff --git a/scripts/slave/gatekeeper_ng_db.py b/scripts/slave/gatekeeper_ng_db.py
new file mode 100755
index 0000000000000000000000000000000000000000..3df6f5ae4ee7cc00dfc34252f1e502bfac6f93fe
--- /dev/null
+++ b/scripts/slave/gatekeeper_ng_db.py
@@ -0,0 +1,209 @@
+#!/usr/bin/env python
+# Copyright 2014 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.
+
+"""Contains configuration and setup of gatekeeper build database.
+
+The databse is a versioned JSON file built of NamedTuples.
+"""
+
+import collections
+import json
+import logging
+import optparse
+import os
+import sys
+
+from common import chromium_utils
+from slave import gatekeeper_ng_config
+
+
+DATA_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+# Bump each time there is an incompatible change in build_db.
+BUILD_DB_VERSION = 1
+
+
+_BuildDB = collections.namedtuple('BuildDB', [
+    'build_db_version',  # An int representing the build_db version.
+    'masters',  # {mastername: {buildername: {buildnumber: BuildDBBuild}}}}
+    'sections',  # {section_hash: human_readable_json_of_gatekeeper_section}
+])
+
+
+_BuildDBBuild = collections.namedtuple('BuildDBBuild', [
+    'finished',  # Whether the build has finished or not.
+    'triggered',  # What gatekeeper sections, if any, have triggered.
+])
+
+
+class JsonNode(object):
+  """Allows for serialization of NamedTuples to JSON."""
+  def _asdict(self):  # pylint: disable=R0201
+    return {}
+
+  # TODO(stip): recursively encode child nodes.
+  def asJson(self):
+    nodes_to_encode = [(k, v) for k, v in self._asdict().iteritems()
+                       if hasattr(v, 'asJson')]
+    standard_nodes = [(k, v) for k, v in self._asdict().iteritems()
+                      if not hasattr(v, 'asJson')]
+    newly_encoded_nodes = [(k, v.asJson()) for k, v in nodes_to_encode]
+
+    return dict(standard_nodes + newly_encoded_nodes)
+
+
+class BuildDB(_BuildDB, JsonNode):
+  pass
+
+
+class BuildDBBuild(_BuildDBBuild, JsonNode):
+  pass
+
+
+class BadConf(Exception):
+  pass
+
+
+def gen_db(**kwargs):
+  """Helper function to generate a default database."""
+  defaults = [('build_db_version', BUILD_DB_VERSION),
+              ('masters', {}),
+              ('sections', {})]
+
+  for key, default in defaults:
+    kwargs.setdefault(key, default)
+
+  return BuildDB(**kwargs)
+
+def gen_build(**kwargs):
+  """Helper function to generate a default build."""
+  defaults = [('finished', False),
+              ('triggered', [])]
+
+  for key, default in defaults:
+    kwargs.setdefault(key, default)
+
+  return BuildDBBuild(**kwargs)
+
+
+def load_from_json(f):
+  """Load a build from a JSON stream."""
+  build_db = gen_db()
+
+  json_build_db = json.load(f)
+
+  if json_build_db.get('build_db_version') != BUILD_DB_VERSION:
+    raise BadConf('file is an older db version: %r (expecting %d)' % (
+        json.build_db.get('build_db_version', 0), BUILD_DB_VERSION))
+
+  masters = json_build_db.get('masters', {})
+  # Convert build dicts into BuildDBBuilds.
+  build_db = gen_db()
+  for mastername, master in masters.iteritems():
+    build_db.masters.setdefault(mastername, {})
+    for buildername, builder in master.iteritems():
+      build_db.masters[mastername].setdefault(buildername, {})
+      for buildnumber, build in builder.iteritems():
+        # Note that buildnumber is forced to be an int here, and
+        # we use * instead of ** -- until the serializer is recursive,
+        # BuildDBBuild will be written as a value list (tuple).
+        build_db.masters[mastername][buildername][
+            int(buildnumber)] = BuildDBBuild(*build)
+
+  return build_db
+
+
+def get_build_db(filename):
+  """Open the build_db file.
+
+  filename: the filename of the build db.
+  """
+  build_db = gen_db()
+
+  if os.path.isfile(filename):
+    print 'loading build_db from', filename
+    try:
+      with open(filename) as f:
+        build_db = load_from_json(f)
+    except BadConf as e:
+      new_fn = '%s.old' % filename
+      logging.warn('error loading %s: %s, moving to %s' % (
+          filename, e, new_fn))
+      chromium_utils.MoveFile(filename, new_fn)
+
+  return build_db
+
+
+def convert_db_to_json(build_db_data, gatekeeper_config, f):
+  """Converts build_db to a format suitable for JSON encoding and writes it."""
+  # Remove all but the last finished build.
+  for builders in build_db_data.masters.values():
+    for builder in builders:
+      unfinished = [(k, v) for k, v in builders[builder].iteritems()
+                    if not v.finished]
+
+      finished = [(k, v) for k, v in builders[builder].iteritems()
+                  if v.finished]
+
+      builders[builder] = dict(unfinished)
+
+      if finished:
+        max_finished = max(finished, key=lambda x: x[0])
+        builders[builder][max_finished[0]] = max_finished[1]
+
+
+  build_db = gen_db(masters=build_db_data.masters)
+
+  # Output the gatekeeper sections we're operating with, so a human reading the
+  # file can debug issues. This is discarded by the parser in get_build_db.
+  used_sections = set([])
+  for masters in build_db_data.masters.values():
+    for builder in masters.values():
+      used_sections |= set(t for b in builder.values() for t in b.triggered)
+
+  for master in gatekeeper_config.values():
+    for section in master:
+      section_hash = gatekeeper_ng_config.gatekeeper_section_hash(section)
+      if section_hash in used_sections:
+        build_db.sections[section_hash] = section
+
+  json.dump(build_db.asJson(), f, cls=gatekeeper_ng_config.SetEncoder,
+            sort_keys=True)
+
+
+def save_build_db(build_db_data, gatekeeper_config, filename):
+  """Save the build_db file.
+
+  build_db: dictionary to jsonize and store as build_db.
+  gatekeeper_config: the gatekeeper config used for this pass.
+  filename: the filename of the build db.
+  """
+  print 'saving build_db to', filename
+  with open(filename, 'wb') as f:
+    convert_db_to_json(build_db_data, gatekeeper_config, f)
+
+
+def main():
+  prog_desc = 'Parses the build_db and outputs to stdout.'
+  usage = '%prog [options]'
+  parser = optparse.OptionParser(usage=(usage + '\n\n' + prog_desc))
+  parser.add_option('--json', default=os.path.join(DATA_DIR, 'gatekeeper.json'),
+                    help='location of gatekeeper configuration file')
+  parser.add_option('--build-db', default='build_db.json',
+                    help='records the build status information for builders')
+  options, _ = parser.parse_args()
+
+  build_db = get_build_db(options.build_db)
+  gatekeeper_config = gatekeeper_ng_config.load_gatekeeper_config(options.json)
+
+  convert_db_to_json(build_db, gatekeeper_config, sys.stdout)
+  print
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())