1# Copyright 2013 The Chromium Authors 2# Use of this source code is governed by a BSD-style license that can be 3# found in the LICENSE file. 4 5 6"""A helper module for parsing JSON objects from perf tests results.""" 7 8 9import json 10 11 12def GetAverageRunInfo(json_data, name): 13 """Summarizes TraceEvent JSON data for performance metrics. 14 15 Example JSON Inputs (More tags can be added but these are required): 16 Measuring Duration: 17 [ 18 { "cat": "Java", 19 "ts": 10000000000, 20 "ph": "S", 21 "name": "TestTrace" 22 }, 23 { "cat": "Java", 24 "ts": 10000004000, 25 "ph": "F", 26 "name": "TestTrace" 27 }, 28 ... 29 ] 30 31 Measuring Call Frequency (FPS): 32 [ 33 { "cat": "Java", 34 "ts": 10000000000, 35 "ph": "I", 36 "name": "TestTraceFPS" 37 }, 38 { "cat": "Java", 39 "ts": 10000004000, 40 "ph": "I", 41 "name": "TestTraceFPS" 42 }, 43 ... 44 ] 45 46 Args: 47 json_data: A list of dictonaries each representing a JSON object. 48 name: The 'name' tag to filter on in the JSON file. 49 50 Returns: 51 A dictionary of result data with the following tags: 52 min: The minimum value tracked. 53 max: The maximum value tracked. 54 average: The average of all the values tracked. 55 count: The number of times the category/name pair was tracked. 56 type: The type of tracking ('Instant' for instant tags and 'Span' for 57 begin/end tags. 58 category: The passed in category filter. 59 name: The passed in name filter. 60 data_points: A list of all of the times used to generate this data. 61 units: The units for the values being reported. 62 63 Raises: 64 Exception: if entry contains invalid data. 65 """ 66 67 def EntryFilter(entry): 68 return entry['cat'] == 'Java' and entry['name'] == name 69 filtered_entries = [j for j in json_data if EntryFilter(j)] 70 71 result = {} 72 73 result['min'] = -1 74 result['max'] = -1 75 result['average'] = 0 76 result['count'] = 0 77 result['type'] = 'Unknown' 78 result['category'] = 'Java' 79 result['name'] = name 80 result['data_points'] = [] 81 result['units'] = '' 82 83 total_sum = 0 84 85 last_val = 0 86 val_type = None 87 for entry in filtered_entries: 88 if not val_type: 89 if 'mem' in entry: 90 val_type = 'mem' 91 92 def GetVal(entry): 93 return entry['mem'] 94 95 result['units'] = 'kb' 96 elif 'ts' in entry: 97 val_type = 'ts' 98 99 def GetVal(entry): 100 return float(entry['ts']) / 1000.0 101 102 result['units'] = 'ms' 103 else: 104 raise Exception('Entry did not contain valid value info: %s' % entry) 105 106 if not val_type in entry: 107 raise Exception('Entry did not contain expected value type "%s" ' 108 'information: %s' % (val_type, entry)) 109 val = GetVal(entry) 110 if (entry['ph'] == 'S' and 111 (result['type'] == 'Unknown' or result['type'] == 'Span')): 112 result['type'] = 'Span' 113 last_val = val 114 elif ((entry['ph'] == 'F' and result['type'] == 'Span') or 115 (entry['ph'] == 'I' and (result['type'] == 'Unknown' or 116 result['type'] == 'Instant'))): 117 if last_val > 0: 118 delta = val - last_val 119 if result['min'] == -1 or result['min'] > delta: 120 result['min'] = delta 121 if result['max'] == -1 or result['max'] < delta: 122 result['max'] = delta 123 total_sum += delta 124 result['count'] += 1 125 result['data_points'].append(delta) 126 if entry['ph'] == 'I': 127 result['type'] = 'Instant' 128 last_val = val 129 if result['count'] > 0: 130 result['average'] = total_sum / result['count'] 131 132 return result 133 134 135def GetAverageRunInfoFromJSONString(json_string, name): 136 """Returns the results from GetAverageRunInfo using a JSON string. 137 138 Args: 139 json_string: The string containing JSON. 140 name: The 'name' tag to filter on in the JSON file. 141 142 Returns: 143 See GetAverageRunInfo Returns section. 144 """ 145 return GetAverageRunInfo(json.loads(json_string), name) 146 147 148def GetAverageRunInfoFromFile(json_file, name): 149 """Returns the results from GetAverageRunInfo using a JSON file. 150 151 Args: 152 json_file: The path to a JSON file. 153 name: The 'name' tag to filter on in the JSON file. 154 155 Returns: 156 See GetAverageRunInfo Returns section. 157 """ 158 with open(json_file, 'r') as f: 159 data = f.read() 160 perf = json.loads(data) 161 162 return GetAverageRunInfo(perf, name) 163