michael@0: # Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: # Use of this source code is governed by a BSD-style license that can be
michael@0: # found in the LICENSE file.
michael@0: 
michael@0: 
michael@0: """A helper module for parsing JSON objects from perf tests results."""
michael@0: 
michael@0: import json
michael@0: 
michael@0: 
michael@0: def GetAverageRunInfo(json_data, name):
michael@0:   """Summarizes TraceEvent JSON data for performance metrics.
michael@0: 
michael@0:   Example JSON Inputs (More tags can be added but these are required):
michael@0:   Measuring Duration:
michael@0:   [
michael@0:     { "cat": "Java",
michael@0:       "ts": 10000000000,
michael@0:       "ph": "S",
michael@0:       "name": "TestTrace"
michael@0:     },
michael@0:     { "cat": "Java",
michael@0:       "ts": 10000004000,
michael@0:       "ph": "F",
michael@0:       "name": "TestTrace"
michael@0:     },
michael@0:     ...
michael@0:   ]
michael@0: 
michael@0:   Measuring Call Frequency (FPS):
michael@0:   [
michael@0:     { "cat": "Java",
michael@0:       "ts": 10000000000,
michael@0:       "ph": "I",
michael@0:       "name": "TestTraceFPS"
michael@0:     },
michael@0:     { "cat": "Java",
michael@0:       "ts": 10000004000,
michael@0:       "ph": "I",
michael@0:       "name": "TestTraceFPS"
michael@0:     },
michael@0:     ...
michael@0:   ]
michael@0: 
michael@0:   Args:
michael@0:     json_data: A list of dictonaries each representing a JSON object.
michael@0:     name: The 'name' tag to filter on in the JSON file.
michael@0: 
michael@0:   Returns:
michael@0:     A dictionary of result data with the following tags:
michael@0:       min: The minimum value tracked.
michael@0:       max: The maximum value tracked.
michael@0:       average: The average of all the values tracked.
michael@0:       count: The number of times the category/name pair was tracked.
michael@0:       type: The type of tracking ('Instant' for instant tags and 'Span' for
michael@0:             begin/end tags.
michael@0:       category: The passed in category filter.
michael@0:       name: The passed in name filter.
michael@0:       data_points: A list of all of the times used to generate this data.
michael@0:       units: The units for the values being reported.
michael@0: 
michael@0:   Raises:
michael@0:     Exception: if entry contains invalid data.
michael@0:   """
michael@0: 
michael@0:   def EntryFilter(entry):
michael@0:     return entry['cat'] == 'Java' and entry['name'] == name
michael@0:   filtered_entries = filter(EntryFilter, json_data)
michael@0: 
michael@0:   result = {}
michael@0: 
michael@0:   result['min'] = -1
michael@0:   result['max'] = -1
michael@0:   result['average'] = 0
michael@0:   result['count'] = 0
michael@0:   result['type'] = 'Unknown'
michael@0:   result['category'] = 'Java'
michael@0:   result['name'] = name
michael@0:   result['data_points'] = []
michael@0:   result['units'] = ''
michael@0: 
michael@0:   total_sum = 0
michael@0: 
michael@0:   last_val = 0
michael@0:   val_type = None
michael@0:   for entry in filtered_entries:
michael@0:     if not val_type:
michael@0:       if 'mem' in entry:
michael@0:         val_type = 'mem'
michael@0: 
michael@0:         def GetVal(entry):
michael@0:           return entry['mem']
michael@0: 
michael@0:         result['units'] = 'kb'
michael@0:       elif 'ts' in entry:
michael@0:         val_type = 'ts'
michael@0: 
michael@0:         def GetVal(entry):
michael@0:           return float(entry['ts']) / 1000.0
michael@0: 
michael@0:         result['units'] = 'ms'
michael@0:       else:
michael@0:         raise Exception('Entry did not contain valid value info: %s' % entry)
michael@0: 
michael@0:     if not val_type in entry:
michael@0:       raise Exception('Entry did not contain expected value type "%s" '
michael@0:                       'information: %s' % (val_type, entry))
michael@0:     val = GetVal(entry)
michael@0:     if (entry['ph'] == 'S' and
michael@0:         (result['type'] == 'Unknown' or result['type'] == 'Span')):
michael@0:       result['type'] = 'Span'
michael@0:       last_val = val
michael@0:     elif ((entry['ph'] == 'F' and result['type'] == 'Span') or
michael@0:           (entry['ph'] == 'I' and (result['type'] == 'Unknown' or
michael@0:                                    result['type'] == 'Instant'))):
michael@0:       if last_val > 0:
michael@0:         delta = val - last_val
michael@0:         if result['min'] == -1 or result['min'] > delta:
michael@0:           result['min'] = delta
michael@0:         if result['max'] == -1 or result['max'] < delta:
michael@0:           result['max'] = delta
michael@0:         total_sum += delta
michael@0:         result['count'] += 1
michael@0:         result['data_points'].append(delta)
michael@0:       if entry['ph'] == 'I':
michael@0:         result['type'] = 'Instant'
michael@0:         last_val = val
michael@0:   if result['count'] > 0: result['average'] = total_sum / result['count']
michael@0: 
michael@0:   return result
michael@0: 
michael@0: 
michael@0: def GetAverageRunInfoFromJSONString(json_string, name):
michael@0:   """Returns the results from GetAverageRunInfo using a JSON string.
michael@0: 
michael@0:   Args:
michael@0:     json_string: The string containing JSON.
michael@0:     name: The 'name' tag to filter on in the JSON file.
michael@0: 
michael@0:   Returns:
michael@0:     See GetAverageRunInfo Returns section.
michael@0:   """
michael@0:   return GetAverageRunInfo(json.loads(json_string), name)
michael@0: 
michael@0: 
michael@0: def GetAverageRunInfoFromFile(json_file, name):
michael@0:   """Returns the results from GetAverageRunInfo using a JSON file.
michael@0: 
michael@0:   Args:
michael@0:     json_file: The path to a JSON file.
michael@0:     name: The 'name' tag to filter on in the JSON file.
michael@0: 
michael@0:   Returns:
michael@0:     See GetAverageRunInfo Returns section.
michael@0:   """
michael@0:   with open(json_file, 'r') as f:
michael@0:     data = f.read()
michael@0:     perf = json.loads(data)
michael@0: 
michael@0:   return GetAverageRunInfo(perf, name)