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| 1 # Copyright 2014 The Chromium Authors. All rights reserved. | |
| 2 # Use of this source code is governed by a BSD-style license that can be | |
| 3 # found in the LICENSE file. | |
| 4 | |
| 5 import base64 | |
| 6 import gzip | |
| 7 import hashlib | |
| 8 import io | |
| 9 import logging | |
| 10 import zlib | |
| 11 | |
| 12 from metrics import Metric | |
| 13 from telemetry.page import page_test | |
| 14 # All network metrics are Chrome only for now. | |
| 15 from telemetry.core.backends.chrome_inspector import inspector_network | |
| 16 from telemetry.value import scalar | |
| 17 | |
| 18 | |
| 19 class NetworkMetricException(page_test.MeasurementFailure): | |
| 20 pass | |
| 21 | |
| 22 | |
| 23 class HTTPResponse(object): | |
| 24 """ Represents an HTTP response from a timeline event.""" | |
| 25 def __init__(self, event): | |
| 26 self._response = ( | |
| 27 inspector_network.InspectorNetworkResponseData.FromTimelineEvent(event)) | |
| 28 self._remote_port = None | |
| 29 if 'response' in event.args and 'remotePort' in event.args['response']: | |
| 30 self._remote_port = event.args['response']['remotePort'] | |
| 31 self._content_length = None | |
| 32 | |
| 33 @property | |
| 34 def response(self): | |
| 35 return self._response | |
| 36 | |
| 37 @property | |
| 38 def remote_port(self): | |
| 39 return self._remote_port | |
| 40 | |
| 41 @property | |
| 42 def url_signature(self): | |
| 43 return hashlib.md5(self.response.url).hexdigest() | |
| 44 | |
| 45 @property | |
| 46 def content_length(self): | |
| 47 if self._content_length is None: | |
| 48 self._content_length = self.GetContentLength() | |
| 49 return self._content_length | |
| 50 | |
| 51 @property | |
| 52 def has_original_content_length(self): | |
| 53 return 'X-Original-Content-Length' in self.response.headers | |
| 54 | |
| 55 @property | |
| 56 def original_content_length(self): | |
| 57 if self.has_original_content_length: | |
| 58 return int(self.response.GetHeader('X-Original-Content-Length')) | |
| 59 return 0 | |
| 60 | |
| 61 @property | |
| 62 def data_saving_rate(self): | |
| 63 if (self.response.served_from_cache or | |
| 64 not self.has_original_content_length or | |
| 65 self.original_content_length <= 0): | |
| 66 return 0.0 | |
| 67 return (float(self.original_content_length - self.content_length) / | |
| 68 self.original_content_length) | |
| 69 | |
| 70 def GetContentLengthFromBody(self): | |
| 71 resp = self.response | |
| 72 body, base64_encoded = resp.GetBody() | |
| 73 if not body: | |
| 74 return 0 | |
| 75 # The binary data like images, etc is base64_encoded. Decode it to get | |
| 76 # the actualy content length. | |
| 77 if base64_encoded: | |
| 78 decoded = base64.b64decode(body) | |
| 79 return len(decoded) | |
| 80 | |
| 81 encoding = resp.GetHeader('Content-Encoding') | |
| 82 if not encoding: | |
| 83 return len(body) | |
| 84 # The response body returned from a timeline event is always decompressed. | |
| 85 # So, we need to compress it to get the actual content length if headers | |
| 86 # say so. | |
| 87 encoding = encoding.lower() | |
| 88 if encoding == 'gzip': | |
| 89 return self.GetGizppedBodyLength(body) | |
| 90 elif encoding == 'deflate': | |
| 91 return len(zlib.compress(body, 9)) | |
| 92 else: | |
| 93 raise NetworkMetricException, ( | |
| 94 'Unknown Content-Encoding %s for %s' % (encoding, resp.url)) | |
| 95 | |
| 96 def GetContentLength(self): | |
| 97 cl = 0 | |
| 98 try: | |
| 99 cl = self.GetContentLengthFromBody() | |
| 100 except Exception, e: | |
| 101 logging.warning('Fail to get content length for %s from body: %s', | |
| 102 self.response.url[:100], e) | |
| 103 if cl == 0: | |
| 104 resp = self.response | |
| 105 cl_header = resp.GetHeader('Content-Length') | |
| 106 if cl_header: | |
| 107 cl = int(cl_header) | |
| 108 else: | |
| 109 body, _ = resp.GetBody() | |
| 110 if body: | |
| 111 cl = len(body) | |
| 112 return cl | |
| 113 | |
| 114 @staticmethod | |
| 115 def GetGizppedBodyLength(body): | |
| 116 if not body: | |
| 117 return 0 | |
| 118 bio = io.BytesIO() | |
| 119 try: | |
| 120 with gzip.GzipFile(fileobj=bio, mode="wb", compresslevel=9) as f: | |
| 121 f.write(body.encode('utf-8')) | |
| 122 except Exception, e: | |
| 123 logging.warning('Fail to gzip response body: %s', e) | |
| 124 raise e | |
| 125 return len(bio.getvalue()) | |
| 126 | |
| 127 | |
| 128 class NetworkMetric(Metric): | |
| 129 """A network metric based on timeline events.""" | |
| 130 | |
| 131 def __init__(self): | |
| 132 super(NetworkMetric, self).__init__() | |
| 133 | |
| 134 # Whether to add detailed result for each sub-resource in a page. | |
| 135 self.add_result_for_resource = False | |
| 136 self.compute_data_saving = False | |
| 137 self._events = None | |
| 138 | |
| 139 def Start(self, page, tab): | |
| 140 self._events = None | |
| 141 tab.StartTimelineRecording() | |
| 142 | |
| 143 def Stop(self, page, tab): | |
| 144 assert self._events is None | |
| 145 tab.StopTimelineRecording() | |
| 146 | |
| 147 def IterResponses(self, tab): | |
| 148 if self._events is None: | |
| 149 self._events = tab.timeline_model.GetAllEventsOfName('HTTPResponse') | |
| 150 if len(self._events) == 0: | |
| 151 return | |
| 152 for e in self._events: | |
| 153 yield self.ResponseFromEvent(e) | |
| 154 | |
| 155 def ResponseFromEvent(self, event): | |
| 156 return HTTPResponse(event) | |
| 157 | |
| 158 def AddResults(self, tab, results): | |
| 159 content_length = 0 | |
| 160 original_content_length = 0 | |
| 161 | |
| 162 for resp in self.IterResponses(tab): | |
| 163 # Ignore content length calculation for cache hit. | |
| 164 if resp.response.served_from_cache: | |
| 165 continue | |
| 166 | |
| 167 resource = resp.response.url | |
| 168 resource_signature = resp.url_signature | |
| 169 cl = resp.content_length | |
| 170 if resp.has_original_content_length: | |
| 171 ocl = resp.original_content_length | |
| 172 if ocl < cl: | |
| 173 logging.warning('original content length (%d) is less than content ' | |
| 174 'length (%d) for resource %s', ocl, cl, resource) | |
| 175 if self.add_result_for_resource: | |
| 176 results.AddValue(scalar.ScalarValue( | |
| 177 results.current_page, | |
| 178 'resource_data_saving_' + resource_signature, 'percent', | |
| 179 resp.data_saving_rate * 100)) | |
| 180 results.AddValue(scalar.ScalarValue( | |
| 181 results.current_page, | |
| 182 'resource_original_content_length_' + resource_signature, 'bytes', | |
| 183 ocl)) | |
| 184 original_content_length += ocl | |
| 185 else: | |
| 186 original_content_length += cl | |
| 187 if self.add_result_for_resource: | |
| 188 results.AddValue(scalar.ScalarValue( | |
| 189 results.current_page, | |
| 190 'resource_content_length_' + resource_signature, 'bytes', cl)) | |
| 191 content_length += cl | |
| 192 | |
| 193 results.AddValue(scalar.ScalarValue( | |
| 194 results.current_page, 'content_length', 'bytes', content_length)) | |
| 195 results.AddValue(scalar.ScalarValue( | |
| 196 results.current_page, 'original_content_length', 'bytes', | |
| 197 original_content_length)) | |
| 198 if self.compute_data_saving: | |
| 199 if (original_content_length > 0 and | |
| 200 original_content_length >= content_length): | |
| 201 saving = (float(original_content_length-content_length) * 100 / | |
| 202 original_content_length) | |
| 203 results.AddValue(scalar.ScalarValue( | |
| 204 results.current_page, 'data_saving', 'percent', saving)) | |
| 205 else: | |
| 206 results.AddValue(scalar.ScalarValue( | |
| 207 results.current_page, 'data_saving', 'percent', 0.0)) | |
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