xref: /aosp_15_r20/external/cronet/components/metrics/serialization/serialization_utils.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1*6777b538SAndroid Build Coastguard Worker // Copyright 2014 The Chromium Authors
2*6777b538SAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be
3*6777b538SAndroid Build Coastguard Worker // found in the LICENSE file.
4*6777b538SAndroid Build Coastguard Worker 
5*6777b538SAndroid Build Coastguard Worker #ifndef COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
6*6777b538SAndroid Build Coastguard Worker #define COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
7*6777b538SAndroid Build Coastguard Worker 
8*6777b538SAndroid Build Coastguard Worker #include <memory>
9*6777b538SAndroid Build Coastguard Worker #include <string>
10*6777b538SAndroid Build Coastguard Worker #include <vector>
11*6777b538SAndroid Build Coastguard Worker 
12*6777b538SAndroid Build Coastguard Worker namespace metrics {
13*6777b538SAndroid Build Coastguard Worker 
14*6777b538SAndroid Build Coastguard Worker class MetricSample;
15*6777b538SAndroid Build Coastguard Worker 
16*6777b538SAndroid Build Coastguard Worker // Metrics helpers to serialize and deserialize metrics collected by
17*6777b538SAndroid Build Coastguard Worker // ChromeOS.
18*6777b538SAndroid Build Coastguard Worker namespace SerializationUtils {
19*6777b538SAndroid Build Coastguard Worker 
20*6777b538SAndroid Build Coastguard Worker // If there are more than 100,000 messages in the file, discard the remaining
21*6777b538SAndroid Build Coastguard Worker // messages to avoid running out of memory.
22*6777b538SAndroid Build Coastguard Worker extern const int kMaxMessagesPerRead;
23*6777b538SAndroid Build Coastguard Worker 
24*6777b538SAndroid Build Coastguard Worker // Deserializes a sample passed as a string and return a sample.
25*6777b538SAndroid Build Coastguard Worker // The return value will either be a scoped_ptr to a Metric sample (if the
26*6777b538SAndroid Build Coastguard Worker // deserialization was successful) or a nullptr scoped_ptr.
27*6777b538SAndroid Build Coastguard Worker std::unique_ptr<MetricSample> ParseSample(const std::string& sample);
28*6777b538SAndroid Build Coastguard Worker 
29*6777b538SAndroid Build Coastguard Worker // Reads all samples from a file and truncates the file when done.
30*6777b538SAndroid Build Coastguard Worker void ReadAndTruncateMetricsFromFile(
31*6777b538SAndroid Build Coastguard Worker     const std::string& filename,
32*6777b538SAndroid Build Coastguard Worker     std::vector<std::unique_ptr<MetricSample>>* metrics);
33*6777b538SAndroid Build Coastguard Worker 
34*6777b538SAndroid Build Coastguard Worker // Reads all samples from a file and deletes the file when done.
35*6777b538SAndroid Build Coastguard Worker void ReadAndDeleteMetricsFromFile(
36*6777b538SAndroid Build Coastguard Worker     const std::string& filename,
37*6777b538SAndroid Build Coastguard Worker     std::vector<std::unique_ptr<MetricSample>>* metrics);
38*6777b538SAndroid Build Coastguard Worker 
39*6777b538SAndroid Build Coastguard Worker // Serializes a sample and write it to filename.
40*6777b538SAndroid Build Coastguard Worker // The format for the message is:
41*6777b538SAndroid Build Coastguard Worker //  message_size, serialized_message
42*6777b538SAndroid Build Coastguard Worker // where
43*6777b538SAndroid Build Coastguard Worker //  * message_size is the total length of the message (message_size +
44*6777b538SAndroid Build Coastguard Worker //    serialized_message) on 4 bytes
45*6777b538SAndroid Build Coastguard Worker //  * serialized_message is the serialized version of sample (using ToString)
46*6777b538SAndroid Build Coastguard Worker //
47*6777b538SAndroid Build Coastguard Worker //  NB: the file will never leave the device so message_size will be written
48*6777b538SAndroid Build Coastguard Worker //  with the architecture's endianness.
49*6777b538SAndroid Build Coastguard Worker bool WriteMetricToFile(const MetricSample& sample, const std::string& filename);
50*6777b538SAndroid Build Coastguard Worker 
51*6777b538SAndroid Build Coastguard Worker // Maximum length of a serialized message
52*6777b538SAndroid Build Coastguard Worker static const size_t kMessageMaxLength = 1024;
53*6777b538SAndroid Build Coastguard Worker 
54*6777b538SAndroid Build Coastguard Worker }  // namespace SerializationUtils
55*6777b538SAndroid Build Coastguard Worker }  // namespace metrics
56*6777b538SAndroid Build Coastguard Worker 
57*6777b538SAndroid Build Coastguard Worker #endif  // COMPONENTS_METRICS_SERIALIZATION_SERIALIZATION_UTILS_H_
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