-
Notifications
You must be signed in to change notification settings - Fork 140
/
message.h
executable file
·543 lines (469 loc) · 14.8 KB
/
message.h
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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
/**
* Copyright (C) 2017 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 <cstdint>
#include "mongo/base/data_type_endian.h"
#include "mongo/base/data_view.h"
#include "mongo/base/encoded_value_storage.h"
#include "mongo/base/static_assert.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
/**
* Maximum accepted message size on the wire protocol.
mongodb协议官方文档参考https://docs.mongodb.com/manual/reference/mongodb-wire-protocol/
*/
const size_t MaxMessageSizeBytes = 48 * 1000 * 1000;
//ServiceEntryPointMongod::handleRequest opCode操作类型和LogicalOp逻辑op转换详见networkOpToLogicalOp
//enum NetworkOp : int32_t { //LogicalOp和NetworkOp的转换见NetworkOp
enum NetworkOp {
opInvalid = 0,
opReply = 1, /* reply. responseTo is set. */
dbUpdate = 2001, /* update object */
dbInsert = 2002,
// dbGetByOID = 2003,
dbQuery = 2004,
dbGetMore = 2005,
dbDelete = 2006,
dbKillCursors = 2007,
// dbCommand_DEPRECATED = 2008,
// dbCommandReply_DEPRECATED = 2009,
dbCommand = 2010,
dbCommandReply = 2011,
dbCompressed = 2012,
//getProtoString
dbMsg = 2013, //3.6版本实际上insert find都是走的该op,参考ServiceEntryPointMongod::handleRequest
};
//检查op是否在NetworkOp范围内,如果不在,说明不支持
inline bool isSupportedRequestNetworkOp(NetworkOp op) {
switch (op) {
case dbUpdate:
case dbInsert:
case dbQuery:
case dbGetMore:
case dbDelete:
case dbKillCursors:
case dbCommand:
case dbCompressed:
case dbMsg:
return true;
case dbCommandReply:
case opReply:
default:
return false;
}
}
//赋值见networkOpToLogicalOp,opCode操作类型和LogicalOp逻辑op转换详见networkOpToLogicalOp
enum class LogicalOp {
opInvalid,
opUpdate,
opInsert, //插入操作在performInserts中使用
opQuery,
opGetMore,
opDelete,
opKillCursors,
opCommand,
opCompressed,
};
inline LogicalOp networkOpToLogicalOp(NetworkOp networkOp) {
switch (networkOp) {
case dbUpdate:
return LogicalOp::opUpdate;
case dbInsert:
return LogicalOp::opInsert;
case dbQuery:
return LogicalOp::opQuery;
case dbGetMore:
return LogicalOp::opGetMore;
case dbDelete:
return LogicalOp::opDelete;
case dbKillCursors:
return LogicalOp::opKillCursors;
case dbMsg:
case dbCommand:
return LogicalOp::opCommand;
case dbCompressed:
return LogicalOp::opCompressed;
default:
int op = int(networkOp);
massert(34348, str::stream() << "cannot translate opcode " << op, !op);
return LogicalOp::opInvalid;
}
}
inline const char* networkOpToString(NetworkOp networkOp) {
switch (networkOp) {
case opInvalid:
return "none";
case opReply:
return "reply";
case dbUpdate:
return "update";
case dbInsert:
return "insert";
case dbQuery:
return "query";
case dbGetMore:
return "getmore";
case dbDelete:
return "remove";
case dbKillCursors:
return "killcursors";
case dbCommand:
return "command";
case dbCommandReply:
return "commandReply";
case dbCompressed:
return "compressed";
case dbMsg:
return "msg";
default:
int op = static_cast<int>(networkOp);
massert(16141, str::stream() << "cannot translate opcode " << op, !op);
return "";
}
}
//不同op
inline const char* logicalOpToString(LogicalOp logicalOp) {
switch (logicalOp) {
case LogicalOp::opInvalid:
return "none";
case LogicalOp::opUpdate:
return "update";
case LogicalOp::opInsert:
return "insert";
case LogicalOp::opQuery:
return "query";
case LogicalOp::opGetMore:
return "getmore";
case LogicalOp::opDelete:
return "remove";
case LogicalOp::opKillCursors:
return "killcursors";
case LogicalOp::opCommand:
return "command";
case LogicalOp::opCompressed:
return "compressed";
default:
MONGO_UNREACHABLE;
}
}
//注意MsgData和MSGHEADER的区别
namespace MSGHEADER {
#pragma pack(1)
/** 头部读取参考:TransportLayerASIO::ASIOSourceTicket::fillImpl
* See http://dochub.mongodb.org/core/mongowireprotocol
msg header messageLength 整个message长度,包括header长度和body长度
requestID 该请求id信息
responseTo 应答id
opCode 操作类型:OP_UPDATE、OP_INSERT、OP_QUERY、OP_DELETE、OP_MSG等
*/ //MSGHEADER::Layout
struct Layout {
//整个message长度,包括header长度和body长度
int32_t messageLength; // total message size, including this
//requestID 该请求id信息
int32_t requestID; // identifier for this message
//getResponseToMsgId解析
int32_t responseTo; // requestID from the original request
// (used in responses from db)
//操作类型:OP_UPDATE、OP_INSERT、OP_QUERY、OP_DELETE、OP_MSG等
int32_t opCode;
};
#pragma pack()
//调用详见TransportLayerASIO::ASIOSourceTicket::_headerCallback
//下面的View继承该类
//ConstView实现数据解析
class ConstView { //MSGHEADER::Layout头部字段解析
public:
typedef ConstDataView view_type;
//初始化构造
ConstView(const char* data) : _data(data) {}
//获取_data地址
const char* view2ptr() const {
return data().view();
}
//TransportLayerASIO::ASIOSourceTicket::_headerCallback
//解析header头部的messageLength字段
int32_t getMessageLength() const {
return data().read<LittleEndian<int32_t>>(offsetof(Layout, messageLength));
}
//解析header头部的requestID字段
int32_t getRequestMsgId() const {
return data().read<LittleEndian<int32_t>>(offsetof(Layout, requestID));
}
//解析header头部的getResponseToMsgId字段
int32_t getResponseToMsgId() const {
return data().read<LittleEndian<int32_t>>(offsetof(Layout, responseTo));
}
//解析header头部的opCode字段
int32_t getOpCode() const {
return data().read<LittleEndian<int32_t>>(offsetof(Layout, opCode));
}
protected:
//mongodb报文数据起始地址
const view_type& data() const {
return _data;
}
private:
//数据部分
view_type _data;
};
//View构造header头部数据
class View : public ConstView {
public:
typedef DataView view_type;
View(char* data) : ConstView(data) {}
using ConstView::view2ptr;
//header起始地址
char* view2ptr() {
return data().view();
}
//以下四个接口进行header赋值
//填充header头部messageLength字段
void setMessageLength(int32_t value) {
data().write(tagLittleEndian(value), offsetof(Layout, messageLength));
}
//填充header头部requestID字段
void setRequestMsgId(int32_t value) {
data().write(tagLittleEndian(value), offsetof(Layout, requestID));
}
//填充header头部responseTo字段
void setResponseToMsgId(int32_t value) {
data().write(tagLittleEndian(value), offsetof(Layout, responseTo));
}
//填充header头部opCode字段
void setOpCode(int32_t value) {
data().write(tagLittleEndian(value), offsetof(Layout, opCode));
}
private:
//指向header起始地址
view_type data() const {
return const_cast<char*>(ConstView::view2ptr());
}
};
class Value : public EncodedValueStorage<Layout, ConstView, View> {
public:
Value() {
MONGO_STATIC_ASSERT(sizeof(Value) == sizeof(Layout));
}
Value(ZeroInitTag_t zit) : EncodedValueStorage<Layout, ConstView, View>(zit) {}
};
} // namespace MSGHEADER
//注意MsgData和MSGHEADER的区别,MSGHEADER主要是头部字段的解析组装,MsgData更加完善,还可以body部分
namespace MsgData {
#pragma pack(1)
struct Layout {
//数据填充组成:header部分
MSGHEADER::Layout header;
//数据填充组成: body部分
char data[4];
};
#pragma pack()
//这里是MsgData,前面的ConstView对应的是MSGHEADER
class ConstView {
public:
ConstView(const char* storage) : _storage(storage) {}
const char* view2ptr() const {
return storage().view();
}
//以下四个接口间接执行前面的MSGHEADER中的头部字段解析
//填充header头部messageLength字段
int32_t getLen() const {
return header().getMessageLength();
}
//填充header头部requestID字段
int32_t getId() const {
return header().getRequestMsgId();
}
//填充header头部responseTo字段
int32_t getResponseToMsgId() const {
return header().getResponseToMsgId();
}
//获取网络数据报文中的opCode字段
NetworkOp getNetworkOp() const {
return NetworkOp(header().getOpCode());
}
//指向body起始地址
const char* data() const {
return storage().view(offsetof(Layout, data));
}
//messageLength长度检查
bool valid() const {
if (getLen() <= 0 || getLen() > (4 * BSONObjMaxInternalSize))
return false;
if (getNetworkOp() < 0 || getNetworkOp() > 30000)
return false;
return true;
}
int64_t getCursor() const {
verify(getResponseToMsgId() > 0);
verify(getNetworkOp() == opReply);
return ConstDataView(data() + sizeof(int32_t)).read<LittleEndian<int64_t>>();
}
int dataLen() const; // len without header
protected:
const ConstDataView& storage() const {
return _storage;
}
//指向header起始地址
MSGHEADER::ConstView header() const {
return storage().view(offsetof(Layout, header));
}
private:
ConstDataView _storage;
};
class View : public ConstView {
public:
View(char* storage) : ConstView(storage) {}
using ConstView::view2ptr;
char* view2ptr() {
return storage().view();
}
//以下四个接口间接执行前面的MSGHEADER中的头部字段构造
//以下四个接口完成msg header赋值
//填充header头部messageLength字段
void setLen(int value) {
return header().setMessageLength(value);
}
//填充header头部messageLength字段
void setId(int32_t value) {
return header().setRequestMsgId(value);
}
//填充header头部messageLength字段
void setResponseToMsgId(int32_t value) {
return header().setResponseToMsgId(value);
}
//填充header头部messageLength字段
void setOperation(int value) {
return header().setOpCode(value);
}
using ConstView::data;
//指向data
char* data() {
return storage().view(offsetof(Layout, data));
}
private:
DataView storage() const {
return const_cast<char*>(ConstView::view2ptr());
}
//指向header头部
MSGHEADER::View header() const {
return storage().view(offsetof(Layout, header));
}
};
class Value : public EncodedValueStorage<Layout, ConstView, View> {
public:
Value() {
MONGO_STATIC_ASSERT(sizeof(Value) == sizeof(Layout));
}
Value(ZeroInitTag_t zit) : EncodedValueStorage<Layout, ConstView, View>(zit) {}
};
//Value为前面的Layout,减4是因为有4字节填充data,所以这个就是header长度
const int MsgDataHeaderSize = sizeof(Value) - 4;
//除去头部后的数据部分长度
inline int ConstView::dataLen() const {
return getLen() - MsgDataHeaderSize;
}
} // namespace MsgData
//DbMessage._msg包含该类成员 message和OpMsgRequest ReplyInterface ReplyBuilderInterface等的关系可以参考factory.cpp实现
class Message {
public:
Message() = default;
explicit Message(SharedBuffer data) : _buf(std::move(data)) {}
//头部header数据
MsgData::View header() const {
verify(!empty());
return _buf.get();
}
//获取网络数据报文中的op字段 opMsgRequestFromAnyProtocol调用
NetworkOp operation() const {
return header().getNetworkOp();
}
MsgData::View singleData() const {
massert(13273, "single data buffer expected", _buf);
return header();
}
//_buf释放为空
bool empty() const {
return !_buf;
}
//获取报文总长度messageLength
int size() const {
if (_buf) {
return MsgData::ConstView(_buf.get()).getLen();
}
return 0;
}
//body长度
int dataSize() const {
return size() - sizeof(MSGHEADER::Value);
}
//buf重置
void reset() {
_buf = {};
}
// use to set first buffer if empty
//_buf直接使用buf空间
void setData(SharedBuffer buf) {
verify(empty());
_buf = std::move(buf);
}
//把msgtxt拷贝到_buf中
void setData(int operation, const char* msgtxt) {
setData(operation, msgtxt, strlen(msgtxt) + 1);
}
//根据operation和msgdata构造一个完整mongodb报文
void setData(int operation, const char* msgdata, size_t len) {
verify(empty());
size_t dataLen = len + sizeof(MsgData::Value) - 4;
_buf = SharedBuffer::allocate(dataLen);
MsgData::View d = _buf.get();
if (len)
memcpy(d.data(), msgdata, len);
d.setLen(dataLen);
d.setOperation(operation);
}
char* buf() {
return _buf.get();
}
const char* buf() const {
return _buf.get();
}
SharedBuffer sharedBuffer() {
return _buf;
}
ConstSharedBuffer sharedBuffer() const {
return _buf;
}
private:
//存放接收数据的buf
SharedBuffer _buf;
};
/**
* Returns an always incrementing value to be used to assign to the next received network message.
*/
int32_t nextMessageId();
} // namespace mongo