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
|
/**
* Copyright (C) 2016 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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 "mongo/base/disallow_copying.h"
#include "mongo/base/status_with.h"
#include "mongo/transport/message_compressor_base.h"
#include <vector>
namespace mongo {
class BSONObj;
class BSONObjBuilder;
class Message;
class MessageCompressorRegistry;
class MessageCompressorManager {
MONGO_DISALLOW_COPYING(MessageCompressorManager);
public:
/*
* Default constructor. Uses the global MessageCompressorRegistry.
*/
MessageCompressorManager();
/*
* Constructs a manager from a specific MessageCompressorRegistry - used by the unit tests
* to test various registry configurations.
*/
explicit MessageCompressorManager(MessageCompressorRegistry* factory);
MessageCompressorManager(MessageCompressorManager&&) = default;
MessageCompressorManager& operator=(MessageCompressorManager&&) = default;
/*
* Called by a client constructing an isMaster request. This function will append the result
* of _registry->getCompressorNames() to the BSONObjBuilder as a BSON array. If no compressors
* are configured, it won't append anything.
*/
void clientBegin(BSONObjBuilder* output);
/*
* Called by a client that has received an isMaster response (received after calling
* clientBegin) and wants to finish negotiating compression.
*
* This looks for a BSON array called "compression" with the server's list of
* requested algorithms. The first algorithm in that array will be used in subsequent calls
* to compressMessage.
*/
void clientFinish(const BSONObj& input);
/*
* Called by a server that has received an isMaster request.
*
* This looks for a BSON array called "compression" in input and appends the union of that
* array and the result of _registry->getCompressorNames(). The first name in the compression
* array in input will be used in subsequent calls to compressMessage
*
* If no compressors are configured that match those requested by the client, then it will
* not append anything to the BSONObjBuilder output.
*/
void serverNegotiate(const BSONObj& input, BSONObjBuilder* output);
/*
* Returns a new Message compressed with the compressor pointed to by _preferred.
*
* If _negotiated is empty (meaning compression was not negotiated or is not supported), then
* it will return a ref-count bumped copy of the input message.
*
* If an error occurs in the compressor, it will return a Status error.
*/
StatusWith<Message> compressMessage(const Message& msg);
/*
* Returns a new Message containing the decompressed copy of the input message.
*
* If the compressor specified in the input message is not supported, it will return a Status
* error.
*
* If an error occurs in the compressor, it will return a Status error.
*
* This can be called before Compression is negotiated with the client. This class has a
* pointer to the global MessageCompressorRegistry and can lookup any message's compressor
* by ID number through that registry. As long as the compressor has been enabled process-wide,
* it can decompress any message without negotiation.
*/
StatusWith<Message> decompressMessage(const Message& msg);
private:
std::vector<MessageCompressorBase*> _negotiated;
MessageCompressorRegistry* _registry;
};
} // namespace mongo
|
