1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef COMPONENTS_METRICS_STRUCTURED_FLUSHED_MAP_H_
#define COMPONENTS_METRICS_STRUCTURED_FLUSHED_MAP_H_
#include <cstdint>
#include <functional>
#include <optional>
#include <string>
#include <vector>
#include "base/memory/scoped_refptr.h"
#include "base/timer/timer.h"
#include "base/types/expected.h"
#include "components/metrics/structured/lib/event_buffer.h" // EventBuffer and FlushError
#include "components/metrics/structured/lib/resource_info.h"
#include "components/metrics/structured/proto/event_storage.pb.h"
#include "third_party/metrics_proto/structured_data.pb.h"
namespace base {
class FilePath;
class SequencedTaskRunner;
} // namespace base
namespace metrics::structured {
// Manages the reading and writing of events written to disk. All write
// operations are enqueued to the same task runner.
//
// Writing a flushed file is performed asynchronously while reading is performed
// synchronously. This is because the Flush API is designed to be called from
// the UI thread where blocking operations are not allowed. The Read API
// is intended to be called from an IO task while final logs are prepared.
//
// When an EventBuffer is flushed, a FlushedKey is used to represent the on-disk
// data and provide some metadata about what is stored. This key is then used to
// read or delete the events.
//
// All events that have been flushed to disk are considered ready to be
// uploaded.
class FlushedMap {
public:
FlushedMap(const base::FilePath& flushed_dir, uint64_t max_size_bytes);
~FlushedMap();
// Deletes all flushed events from disk.
void Purge();
// Flushes |buffer| to disk. A key is returned that is used to identify the
// on-disk events.
//
// |buffer| defines how the flushing occurs.
void Flush(EventBuffer<StructuredEventProto>& buffer,
FlushedCallback callback);
// Reads the events stored at |key|.
std::optional<EventsProto> ReadKey(const FlushedKey& key) const;
// Deletes the events of |key|.
void DeleteKey(const FlushedKey& key);
void DeleteKeys(const std::vector<FlushedKey>& keys);
const std::vector<FlushedKey>& keys() const { return keys_; }
const ResourceInfo& resource_info() const { return resource_info_; }
bool empty() const { return keys().empty(); }
private:
// Generates a new path under |flushed_dir_| to store the events. The
// filename is generated using UUID.
base::FilePath GenerateFilePath() const;
// Starts a task that builds the list of in-memory keys.
void LoadKeysFromDir(const base::FilePath& dir);
// Traverses |dir| building a list of keys.
//
// It is assumed that all of the files in |dir| store serialized EventsProtos.
void BuildKeysFromDir(const base::FilePath& dir);
// Flushed map operations that need to be handled post flush.
void OnFlushed(FlushedCallback callback,
base::expected<FlushedKey, FlushError> key);
// The directory where events are flushed.
base::FilePath flushed_dir_;
// List of all the keys for flushed events.
std::vector<FlushedKey> keys_;
// Manages the amount of resource used by |this|.
ResourceInfo resource_info_;
scoped_refptr<base::SequencedTaskRunner> task_runner_;
base::WeakPtrFactory<FlushedMap> weak_factory_{this};
};
} // namespace metrics::structured
#endif // COMPONENTS_METRICS_STRUCTURED_FLUSHED_MAP_H_
|
