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 #ifndef COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_ 6 #define COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_ 7 8 #include <string> 9 10 #include "base/memory/scoped_ptr.h" 11 #include "base/memory/scoped_vector.h" 12 13 namespace metrics { 14 15 class MetricSample; 16 17 // Metrics helpers to serialize and deserialize metrics collected by 18 // ChromeOS. 19 namespace SerializationUtils { 20 21 // Deserializes a sample passed as a string and return a sample. 22 // The return value will either be a scoped_ptr to a Metric sample (if the 23 // deserialization was successful) or a NULL scoped_ptr. 24 scoped_ptr<MetricSample> ParseSample(const std::string& sample); 25 26 // Reads all samples from a file and truncate the file when done. 27 void ReadAndTruncateMetricsFromFile(const std::string& filename, 28 ScopedVector<MetricSample>* metrics); 29 30 // Serializes a sample and write it to filename. 31 // The format for the message is: 32 // message_size, serialized_message 33 // where 34 // * message_size is the total length of the message (message_size + 35 // serialized_message) on 4 bytes 36 // * serialized_message is the serialized version of sample (using ToString) 37 // 38 // NB: the file will never leave the device so message_size will be written 39 // with the architecture's endianness. 40 bool WriteMetricToFile(const MetricSample& sample, const std::string& filename); 41 42 // Maximum length of a serialized message 43 static const int kMessageMaxLength = 1024; 44 45 } // namespace SerializationUtils 46 } // namespace metrics 47 48 #endif // COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_ 49