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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <boost/filesystem/path.hpp>
#include <cstddef>
#include <cstdint>
#include <fstream>
#include <vector>
#include "mongo/base/status.h"
#include "mongo/db/ftdc/compressor.h"
#include "mongo/db/jsobj.h"
namespace mongo {
/**
* Manages writing to an append only archive file, and an interim file.
* - The archive file is designed to write complete metric chunks.
* - The interim file writes smaller chunks in case of process failure.
*
* Note: This class never reads from the interim file. It is the callers responsibility to check
* for unclean shutdown as this file. An unclean shutdown will mean there is valid data in the
* interim file. If the shutdown is clean, the interim file will contain zeros as the leading
* 8 bytes instead of a valid BSON length.
*
* The chunks in the archive stream will have better compression since it compresses larger chunks
* of data.
*
* File format is compatible with mongodump as it is just a sequential series of bson documents
*
* File rotation and cleanup is not handled by this class.
*/
class FTDCFileWriter {
MONGO_DISALLOW_COPYING(FTDCFileWriter);
public:
FTDCFileWriter(const FTDCConfig* config) : _config(config), _compressor(_config) {}
~FTDCFileWriter();
/**
* Open both an archive file, and interim file.
*/
Status open(const boost::filesystem::path& file);
/**
* Write a BSON document as a metadata type to the archive log.
*/
Status writeMetadata(const BSONObj& metadata, Date_t date);
/**
* Write a sample to interim and/or archive log as needed.
*/
Status writeSample(const BSONObj& sample, Date_t date);
/**
* Close all the files and shutdown cleanly by zeroing the beginning of the interim file.
*/
Status close();
/**
* Get the size of data written to file. Size of file after file is closed due to effects of
* compression may be different.
*/
std::size_t getSize() const {
return _size + _sizeInterim;
}
public:
/**
* Test hook that closes the files without moving interim results to the archive log.
* Note: OS Buffers are still flushes correctly though.
*/
void closeWithoutFlushForTest();
private:
/**
* Flush all changes to disk.
*/
Status flush(const boost::optional<ConstDataRange>&, Date_t date);
/**
* Write a buffer to the beginning of the interim file.
*/
Status writeInterimFileBuffer(ConstDataRange buf);
/**
* Append a buffer to the archive file.
*/
Status writeArchiveFileBuffer(ConstDataRange buf);
private:
// Config
const FTDCConfig* const _config;
// Archive file name
boost::filesystem::path _archiveFile;
// Interim file name
boost::filesystem::path _interimFile;
// Interim temp file name
boost::filesystem::path _interimTempFile;
// Append only archive stream
std::ofstream _archiveStream;
// FTDC compressor
FTDCCompressor _compressor;
// Size of archive file
std::size_t _size{0};
// Size of interim file
std::size_t _sizeInterim{0};
};
} // namespace mongo
|
