Merge all Field Trial Testing Configuration Together

tools/variations/fieldtrial_to_struct.py

 #!/usr/bin/env python
 # Copyright 2015 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.
 
+import itertools
 import json
 import os.path
 import sys
 import optparse
 _script_path = os.path.realpath(__file__)
 
 sys.path.insert(0, os.path.normpath(_script_path + "/../../json_comment_eater"))
 try:
   import json_comment_eater
 finally:
   sys.path.pop(0)
 
 sys.path.insert(0, os.path.normpath(_script_path + "/../../json_to_struct"))
 try:
   import json_to_struct
 finally:
   sys.path.pop(0)
 
 def _Load(filename):
   """Loads a JSON file into a Python object and return this object.
   """
   with open(filename, 'r') as handle:
     result = json.loads(json_comment_eater.Nom(handle.read()))
   return result
 
-def _LoadFieldTrialConfig(filename):
+def _LoadFieldTrialConfig(filename, platform):
   """Loads a field trial config JSON and converts it into a format that can be
   used by json_to_struct.
   """
-  return _FieldTrialConfigToDescription(_Load(filename))
+  return _FieldTrialConfigToDescription(_Load(filename), platform)
 
-def _CreateGroup(group_data):
-  group = {'name': group_data['group_name']}
-  params_data = group_data.get('params')
+def _CreateExperiment(experiment_data):
+  experiment = {'name': experiment_data['name']}
+  params_data = experiment_data.get('params')
   if (params_data):
-    group['params'] = [{'key': param, 'value': params_data[param]}
+    experiment['params'] = [{'key': param, 'value': params_data[param]}
                           for param in sorted(params_data.keys())];
-  enable_features_data = group_data.get('enable_features')
+  enable_features_data = experiment_data.get('enable_features')
   if enable_features_data:
-    group['enable_features'] = enable_features_data
-  disable_features_data = group_data.get('disable_features')
+    experiment['enable_features'] = enable_features_data
+  disable_features_data = experiment_data.get('disable_features')
   if disable_features_data:
-    group['disable_features'] = disable_features_data
-  return group
+    experiment['disable_features'] = disable_features_data
+  return experiment
 
-def _CreateTrial(trial_name, groups):
+def _CreateTrial(study_name, experiment_configs, platform):
+  """Returns the applicable experiments for |study_name| and |platform|. This
+  iterates through all of the experiment_configs for |study_name| and picks out
+  the applicable experiments based off of the valid platforms.
+  """
+  platform_experiment_lists = [
+      config['experiments'] for config in experiment_configs
+      if platform in config['platforms']]
+  platform_experiments = list(itertools.chain.from_iterable(
+      platform_experiment_lists))
   return {
-    'name': trial_name,
-    'groups': [_CreateGroup(group) for group in groups],
+    'name': study_name,
+    'groups': [_CreateExperiment(experiment)
+               for experiment in platform_experiments],
   }
 
-def _FieldTrialConfigToDescription(config):
+def _GenerateTrials(config, platform):
+  for study_name in sorted(config.keys()):
+    study = _CreateTrial(study_name, config[study_name], platform)
+    # To avoid converting studies with empty groups (e.g. the study doesn't
+    # apply to the target platform), this generator only yields studies that
+    # have non-empty groups.
+    if study['groups']:
+      yield study
+
+def _FieldTrialConfigToDescription(config, platform):
   return {
     'elements': {
       'kFieldTrialConfig': {
-        'trials': [_CreateTrial(trial_name, config[trial_name])
-                      for trial_name in sorted(config.keys())]
+        'trials': [study for study in _GenerateTrials(config, platform)]
       }
     }
   }
 
 def main(arguments):
   parser = optparse.OptionParser(
       description='Generates a struct from a JSON description.',
-      usage='usage: %prog [option] -s schema description')
+      usage='usage: %prog [option] -s schema -p platform description')
   parser.add_option('-b', '--destbase',
       help='base directory of generated files.')
   parser.add_option('-d', '--destdir',
       help='directory to output generated files, relative to destbase.')
   parser.add_option('-n', '--namespace',
       help='C++ namespace for generated files. e.g search_providers.')
+  parser.add_option('-p', '--platform',
+      help='target platform for the field trial, mandatory.')
   parser.add_option('-s', '--schema', help='path to the schema file, '
       'mandatory.')
   parser.add_option('-o', '--output', help='output filename, '
       'mandatory.')
   parser.add_option('-y', '--year',
       help='year to put in the copy-right.')
   (opts, args) = parser.parse_args(args=arguments)
 
   if not opts.schema:
     parser.error('You must specify a --schema.')
 
+  if not opts.platform:
+    parser.error('You must specify a --platform.')
+
+  supported_platforms = ['android', 'chromeos', 'ios', 'linux', 'mac', 'win']
+  if opts.platform not in supported_platforms:
+    parser.error('\'%s\' is an unknown platform. Supported platforms: %s' %
+        (opts.platform, supported_platforms))
+
   description_filename = os.path.normpath(args[0])
   shortroot = opts.output
   if opts.destdir:
     output_root = os.path.join(os.path.normpath(opts.destdir), shortroot)
   else:
     output_root = shortroot
 
   if opts.destbase:
     basepath = os.path.normpath(opts.destbase)
   else:
     basepath = ''
 
   schema = _Load(opts.schema)
-  description = _LoadFieldTrialConfig(description_filename)
+  description = _LoadFieldTrialConfig(description_filename, opts.platform)
   json_to_struct.GenerateStruct(
       basepath, output_root, opts.namespace, schema, description,
       os.path.split(description_filename)[1], os.path.split(opts.schema)[1],
       opts.year)
 
 if __name__ == '__main__':
   main(sys.argv[1:])