sandwich: Refactor to use more existing code.

tools/android/loading/pull_sandwich_metrics.py

 #! /usr/bin/env python
 # Copyright 2016 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.
 
 """Pull a sandwich run's output directory's metrics from traces into a CSV.
 
 python pull_sandwich_metrics.py -h
 """
 
 import argparse
 import csv
 import json
 import logging
 import os
 import sys
 
+import loading_trace as loading_trace_module
+import tracing
+
 
 CATEGORIES = ['blink.user_timing', 'disabled-by-default-memory-infra']
 
 _CSV_FIELD_NAMES = [
     'id',
     'url',
     'total_load',
     'onload',
     'browser_malloc_avg',
     'browser_malloc_max']
 
 _TRACKED_EVENT_NAMES = set(['requestStart', 'loadEventStart', 'loadEventEnd'])
 
 
-def _GetBrowserPID(trace):
+def _GetBrowserPID(tracing_track):
   """Get the browser PID from a trace.
 
   Args:
-    trace: The cached trace.
+    tracing_track: The tracing.TracingTrack.
 
   Returns:
     The browser's PID as an integer.
   """
-  for event in trace['traceEvents']:
-    if event['cat'] != '__metadata' or event['name'] != 'process_name':
+  for event in tracing_track.GetEvents():
+    if event.category != '__metadata' or event.name != 'process_name':
       continue
-    if event['args']['name'] == 'Browser':
-      return event['pid']
+    if event.args['name'] == 'Browser':
+      return event.pid
   raise ValueError('couldn\'t find browser\'s PID')
 
 
-def _GetBrowserDumpEvents(trace):
-  """Get the browser memory dump events from a trace.
+def _GetBrowserDumpEvents(tracing_track):
+  """Get the browser memory dump events from a tracing track.
 
   Args:
-    trace: The cached trace.
+    tracing_track: The tracing.TracingTrack.
 
   Returns:
     List of memory dump events.
   """
-  browser_pid = _GetBrowserPID(trace)
+  browser_pid = _GetBrowserPID(tracing_track)
   browser_dumps_events = []
-  for event in trace['traceEvents']:
-    if event['cat'] != 'disabled-by-default-memory-infra':
+  for event in tracing_track.GetEvents():
+    if event.category != 'disabled-by-default-memory-infra':
       continue
-    if event['ph'] != 'v' or event['name'] != 'periodic_interval':
+    if event.type != 'v' or event.name != 'periodic_interval':
       continue
     # Ignore dump events for processes other than the browser process
-    if event['pid'] != browser_pid:
+    if event.pid != browser_pid:
       continue
     browser_dumps_events.append(event)
   if len(browser_dumps_events) == 0:
     raise ValueError('No browser dump events found.')
   return browser_dumps_events
 
 
-def _GetWebPageTrackedEvents(trace):
-  """Get the web page's tracked events from a trace.
+def _GetWebPageTrackedEvents(tracing_track):
+  """Get the web page's tracked events from a tracing track.
 
   Args:
-    trace: The cached trace.
+    tracing_track: The tracing.TracingTrack.
 
   Returns:
     Dictionary all tracked events.
   """
   main_frame = None
   tracked_events = {}
-  for event in trace['traceEvents']:
-    if event['cat'] != 'blink.user_timing':
+  for event in tracing_track.GetEvents():
+    if event.category != 'blink.user_timing':
       continue
-    event_name = event['name']
+    event_name = event.name
     # Ignore events until about:blank's unloadEventEnd that give the main
     # frame id.
     if not main_frame:
       if event_name == 'unloadEventEnd':
-        main_frame = event['args']['frame']
+        main_frame = event.args['frame']
         logging.info('found about:blank\'s event \'unloadEventEnd\'')
       continue
     # Ignore sub-frames events. requestStart don't have the frame set but it
     # is fine since tracking the first one after about:blank's unloadEventEnd.
-    if 'frame' in event['args'] and event['args']['frame'] != main_frame:
+    if 'frame' in event.args and event.args['frame'] != main_frame:
       continue
     if event_name in _TRACKED_EVENT_NAMES and event_name not in tracked_events:
       logging.info('found url\'s event \'%s\'' % event_name)
       tracked_events[event_name] = event
   assert len(tracked_events) == len(_TRACKED_EVENT_NAMES)
   return tracked_events
 
 
-def _PullMetricsFromTrace(trace):
+def _PullMetricsFromLoadingTrace(loading_trace):
   """Pulls all the metrics from a given trace.
 
   Args:
-    trace: The cached trace.
+    loading_trace: loading_trace_module.LoadingTrace.
 
   Returns:
     Dictionary with all _CSV_FIELD_NAMES's field set (except the 'id').
   """
-  browser_dump_events = _GetBrowserDumpEvents(trace)
-  web_page_tracked_events = _GetWebPageTrackedEvents(trace)
+  browser_dump_events = _GetBrowserDumpEvents(loading_trace.tracing_track)
+  web_page_tracked_events = _GetWebPageTrackedEvents(
+      loading_trace.tracing_track)
 
   browser_malloc_sum = 0
   browser_malloc_max = 0
   for dump_event in browser_dump_events:
-    attr = dump_event['args']['dumps']['allocators']['malloc']['attrs']['size']
+    attr = dump_event.args['dumps']['allocators']['malloc']['attrs']['size']
     assert attr['units'] == 'bytes'
     size = int(attr['value'], 16)
     browser_malloc_sum += size
     browser_malloc_max = max(browser_malloc_max, size)
 
   return {
-    'total_load': (web_page_tracked_events['loadEventEnd']['ts'] -
-                   web_page_tracked_events['requestStart']['ts']),
-    'onload': (web_page_tracked_events['loadEventEnd']['ts'] -
-               web_page_tracked_events['loadEventStart']['ts']),
+    'total_load': (web_page_tracked_events['loadEventEnd'].start_msec -
+                   web_page_tracked_events['requestStart'].start_msec),
+    'onload': (web_page_tracked_events['loadEventEnd'].start_msec -
+               web_page_tracked_events['loadEventStart'].start_msec),
     'browser_malloc_avg': browser_malloc_sum / float(len(browser_dump_events)),
     'browser_malloc_max': browser_malloc_max
   }
 
 
 def _PullMetricsFromOutputDirectory(output_directory_path):
   """Pulls all the metrics from all the traces of a sandwich run directory.
 
   Args:
     output_directory_path: The sandwich run's output directory to pull the
@@ skipping 12 matching lines @@
     if not os.path.isdir(os.path.join(output_directory_path, node_name)):
       continue
     try:
       page_id = int(node_name)
     except ValueError:
       continue
     trace_path = os.path.join(output_directory_path, node_name, 'trace.json')
     if not os.path.isfile(trace_path):
       continue
     logging.info('processing \'%s\'' % trace_path)
-    with open(trace_path) as trace_file:
-      trace = json.load(trace_file)
-      trace_metrics = _PullMetricsFromTrace(trace)
-      trace_metrics['id'] = page_id
-      trace_metrics['url'] = run_infos['urls'][page_id]
-      metrics.append(trace_metrics)
+    loading_trace = loading_trace_module.LoadingTrace.FromJsonFile(trace_path)
+    trace_metrics = _PullMetricsFromLoadingTrace(loading_trace)
+    trace_metrics['id'] = page_id
+    trace_metrics['url'] = run_infos['urls'][page_id]
+    metrics.append(trace_metrics)
   assert len(metrics) > 0, ('Looks like \'{}\' was not a sandwich ' +
                             'run directory.').format(output_directory_path)
   return metrics
 
 
 def main():
   logging.basicConfig(level=logging.INFO)
 
   parser = argparse.ArgumentParser()
   parser.add_argument('output', type=str,
                       help='Output directory of run_sandwich.py command.')
   args = parser.parse_args()
 
   trace_metrics_list = _PullMetricsFromOutputDirectory(args.output)
   trace_metrics_list.sort(key=lambda e: e['id'])
   cs_file_path = os.path.join(args.output, 'trace_analysis.csv')
   with open(cs_file_path, 'w') as csv_file:
     writer = csv.DictWriter(csv_file, fieldnames=_CSV_FIELD_NAMES)
     writer.writeheader()
     for trace_metrics in trace_metrics_list:
       writer.writerow(trace_metrics)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())