-
Notifications
You must be signed in to change notification settings - Fork 2.1k
/
binlog_event_json.go
654 lines (559 loc) · 17.4 KB
/
binlog_event_json.go
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
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
/*
Copyright 2019 The Vitess Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package mysql
import (
"encoding/binary"
"fmt"
"math"
"vitess.io/vitess/go/vt/log"
"github.com/spyzhov/ajson"
querypb "vitess.io/vitess/go/vt/proto/query"
)
/*
References:
* C source of mysql json data type implementation
https://fossies.org/linux/mysql/sql/json_binary.cc
* nice description of MySQL's json representation
https://lafengnan.gitbooks.io/blog/content/mysql/chapter2.html
* java/python connector links: useful for test cases and reverse engineering
https://github.com/shyiko/mysql-binlog-connector-java/pull/119/files
https://github.com/noplay/python-mysql-replication/blob/175df28cc8b536a68522ff9b09dc5440adad6094/pymysqlreplication/packet.py
*/
//region debug-only
//TODO remove once the json refactor is tested live
var jsonDebug = false
func jlog(tpl string, vals ...interface{}) {
if !jsonDebug {
return
}
log.Infof("JSON:"+tpl+"\n", vals...)
_ = printASCIIBytes
}
func printASCIIBytes(data []byte) {
if !jsonDebug {
return
}
s := ""
for _, c := range data {
if c < 127 && c > 32 {
s += fmt.Sprintf("%c ", c)
} else {
s += fmt.Sprintf("%02d ", c)
}
}
log.Infof("[%s]", s)
}
// only used for logging/debugging
var jsonTypeToName = map[uint]string{
jsonSmallObject: "sObject",
jsonLargeObject: "lObject",
jsonSmallArray: "sArray",
jsonLargeArray: "lArray",
jsonLiteral: "literal",
jsonInt16: "int16",
jsonUint16: "uint16",
jsonInt32: "int32",
jsonUint32: "uint32",
jsonInt64: "int64",
jsonUint64: "uint64",
jsonDouble: "double", //0x0b
jsonString: "string", //0x0c a utf8mb4 string
jsonOpaque: "opaque", //0x0f "custom" data
}
func jsonDataTypeToString(typ uint) string {
sType, ok := jsonTypeToName[typ]
if !ok {
return "undefined"
}
return sType
}
//endregion
// provides the single API function, used to convert json from binary format used in binlogs to a string representation
func getJSONValue(data []byte) (string, error) {
var ast *ajson.Node
var err error
if len(data) == 0 {
ast = ajson.NullNode("")
} else {
ast, err = binlogJSON.parse(data)
if err != nil {
return "", err
}
}
bytes, err := ajson.Marshal(ast)
if err != nil {
return "", err
}
return string(bytes), nil
}
var binlogJSON *BinlogJSON
func init() {
binlogJSON = &BinlogJSON{
plugins: make(map[jsonDataType]jsonPlugin),
}
}
//region plugin manager
// BinlogJSON contains the plugins for all json types and methods for parsing the
// binary json representation of a specific type from the binlog
type BinlogJSON struct {
plugins map[jsonDataType]jsonPlugin
}
// parse decodes a value from the binlog
func (jh *BinlogJSON) parse(data []byte) (node *ajson.Node, err error) {
// pos keeps track of the offset of the current node being parsed
pos := 0
typ := data[pos]
jlog("Top level object is type %s\n", jsonDataTypeToString(uint(typ)))
pos++
return jh.getNode(jsonDataType(typ), data, pos)
}
// each plugin registers itself in init()s
func (jh *BinlogJSON) register(typ jsonDataType, Plugin jsonPlugin) {
jh.plugins[typ] = Plugin
}
// gets the node at this position
func (jh *BinlogJSON) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
Plugin := jh.plugins[typ]
if Plugin == nil {
return nil, fmt.Errorf("Plugin not found for type %d", typ)
}
return Plugin.getNode(typ, data, pos)
}
//endregion
//region enums
// jsonDataType has the values used in the mysql json binary representation to denote types.
// We have string, literal(true/false/null), number, object or array types.
// large object => doc size > 64K: you get pointers instead of inline values.
type jsonDataType byte
// type mapping as defined by the mysql json representation
const (
jsonSmallObject = 0
jsonLargeObject = 1
jsonSmallArray = 2
jsonLargeArray = 3
jsonLiteral = 4
jsonInt16 = 5
jsonUint16 = 6
jsonInt32 = 7
jsonUint32 = 8
jsonInt64 = 9
jsonUint64 = 10 //0x0a
jsonDouble = 11 //0x0b
jsonString = 12 //0x0c a utf8mb4 string
jsonOpaque = 15 //0x0f "custom" data
)
// literals in the binary json format can be one of three types: null, true, false
type jsonDataLiteral byte
// this is how mysql maps the three literals in the binlog
const (
jsonNullLiteral = '\x00'
jsonTrueLiteral = '\x01'
jsonFalseLiteral = '\x02'
)
//endregion
//region util funcs
// in objects and arrays some values are inlined, other types have offsets into the raw data.
// literals (true/false/null) and 16bit integers are always inlined.
// for large documents 32bit integers are also inlined.
// principle is that two byte values are inlined in "small", and four byte in "large" docs
func isInline(typ jsonDataType, large bool) bool {
switch typ {
case jsonLiteral, jsonInt16, jsonUint16:
return true
case jsonInt32, jsonUint32:
if large {
return true
}
}
return false
}
// readInt returns either a 32-bit or a 16-bit int from the passed buffer. Which one it is,
// depends on whether the document is "large" or not.
// JSON documents stored are considered "large" if the size of the stored json document is
// more than 64K bytes. Values of non-inlined types are stored as offsets into the document.
// The int returned is either an (i) offset into the raw data, (ii) count of elements, or (iii) size of the represented data structure.
// (This design decision allows a fixed number of bytes to be used for representing object keys and array indices.)
// readInt also returns the new position (by advancing the position by the number of bytes read).
func readInt(data []byte, pos int, large bool) (int, int) {
if large {
return int(data[pos]) +
int(data[pos+1])<<8 +
int(data[pos+2])<<16 +
int(data[pos+3])<<24,
pos + 4
}
return int(data[pos]) +
int(data[pos+1])<<8, pos + 2
}
// readVariableLength implements the logic to decode the length
// of an arbitrarily long string as implemented by the mysql server
// https://github.com/mysql/mysql-server/blob/5.7/sql/json_binary.cc#L234
// https://github.com/mysql/mysql-server/blob/8.0/sql/json_binary.cc#L283
// readVariableLength also returns the new position (by advancing the position by the number of bytes read).
func readVariableLength(data []byte, pos int) (int, int) {
var bb byte
var length int
var idx byte
for {
bb = data[pos]
pos++
length |= int(bb&0x7f) << (7 * idx)
// if the high bit is 1, the integer value of the byte will be negative.
// high bit of 1 signifies that the next byte is part of the length encoding.
if int8(bb) >= 0 {
break
}
idx++
}
return length, pos
}
// getElem returns the json value found inside json objects and arrays at the provided position
func getElem(data []byte, pos int, large bool) (*ajson.Node, int, error) {
var elem *ajson.Node
var err error
var offset int
typ := jsonDataType(data[pos])
pos++
if isInline(typ, large) {
elem, err = binlogJSON.getNode(typ, data, pos)
if err != nil {
return nil, 0, err
}
if large {
pos += 4
} else {
pos += 2
}
} else {
offset, pos = readInt(data, pos, large)
if offset >= len(data) { // consistency check, should only come here is there is a bug in the code
log.Errorf("unable to decode element")
return nil, 0, fmt.Errorf("unable to decode element: %+v", data)
}
newData := data[offset:]
//newPos ignored because this is an offset into the "extra" section of the buffer
elem, err = binlogJSON.getNode(typ, newData, 1)
if err != nil {
return nil, 0, err
}
}
return elem, pos, nil
}
//endregion
// json sub-type interface
// one plugin for each sub-type, plugins are stateless and initialized on load via individual init() functions
type jsonPlugin interface {
getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error)
}
type jsonPluginInfo struct {
name string
types []jsonDataType
}
//region int plugin
func init() {
newIntPlugin()
}
type intPlugin struct {
info *jsonPluginInfo
sizes map[jsonDataType]int
}
var _ jsonPlugin = (*intPlugin)(nil)
func (ih intPlugin) getVal(typ jsonDataType, data []byte, pos int) (value float64) {
var val uint64
var val2 float64
size := ih.sizes[typ]
for i := 0; i < size; i++ {
val = val + uint64(data[pos+i])<<(8*i)
}
switch typ {
case jsonInt16:
val2 = float64(int16(val))
case jsonUint16:
val2 = float64(uint16(val))
case jsonInt32:
val2 = float64(int32(val))
case jsonUint32:
val2 = float64(uint32(val))
case jsonInt64:
val2 = float64(int64(val))
case jsonUint64:
val2 = float64(val)
case jsonDouble:
val2 = math.Float64frombits(val)
}
return val2
}
func (ih intPlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
val := ih.getVal(typ, data, pos)
node = ajson.NumericNode("", val)
return node, nil
}
func newIntPlugin() *intPlugin {
ih := &intPlugin{
info: &jsonPluginInfo{
name: "Int",
types: []jsonDataType{jsonInt64, jsonInt32, jsonInt16, jsonUint16, jsonUint32, jsonUint64, jsonDouble},
},
sizes: make(map[jsonDataType]int),
}
ih.sizes = map[jsonDataType]int{
jsonUint64: 8,
jsonInt64: 8,
jsonUint32: 4,
jsonInt32: 4,
jsonUint16: 2,
jsonInt16: 2,
jsonDouble: 8,
}
for _, typ := range ih.info.types {
binlogJSON.register(typ, ih)
}
return ih
}
//endregion
//region literal plugin
func init() {
newLiteralPlugin()
}
type literalPlugin struct {
info *jsonPluginInfo
}
var _ jsonPlugin = (*literalPlugin)(nil)
func (lh literalPlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
val := jsonDataLiteral(data[pos])
switch val {
case jsonNullLiteral:
node = ajson.NullNode("")
case jsonTrueLiteral:
node = ajson.BoolNode("", true)
case jsonFalseLiteral:
node = ajson.BoolNode("", false)
default:
return nil, fmt.Errorf("unknown literal value %v", val)
}
return node, nil
}
func newLiteralPlugin() *literalPlugin {
lh := &literalPlugin{
info: &jsonPluginInfo{
name: "Literal",
types: []jsonDataType{jsonLiteral},
},
}
binlogJSON.register(jsonLiteral, lh)
return lh
}
//endregion
//region opaque plugin
func init() {
newOpaquePlugin()
}
type opaquePlugin struct {
info *jsonPluginInfo
}
var _ jsonPlugin = (*opaquePlugin)(nil)
// other types are stored as catch-all opaque types: documentation on these is scarce.
// we currently know about (and support) date/time/datetime/decimal.
func (oh opaquePlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
dataType := data[pos]
start := 3 // account for length of stored value
end := start + 8 // all currently supported opaque data types are 8 bytes in size
switch dataType {
case TypeDate:
raw := binary.LittleEndian.Uint64(data[start:end])
value := raw >> 24
yearMonth := (value >> 22) & 0x01ffff // 17 bits starting at 22nd
year := yearMonth / 13
month := yearMonth % 13
day := (value >> 17) & 0x1f // 5 bits starting at 17th
dateString := fmt.Sprintf("%04d-%02d-%02d", year, month, day)
node = ajson.StringNode("", dateString)
case TypeTime:
raw := binary.LittleEndian.Uint64(data[start:end])
value := raw >> 24
hour := (value >> 12) & 0x03ff // 10 bits starting at 12th
minute := (value >> 6) & 0x3f // 6 bits starting at 6th
second := value & 0x3f // 6 bits starting at 0th
microSeconds := raw & 0xffffff // 24 lower bits
timeString := fmt.Sprintf("%02d:%02d:%02d.%06d", hour, minute, second, microSeconds)
node = ajson.StringNode("", timeString)
case TypeDateTime:
raw := binary.LittleEndian.Uint64(data[start:end])
value := raw >> 24
yearMonth := (value >> 22) & 0x01ffff // 17 bits starting at 22nd
year := yearMonth / 13
month := yearMonth % 13
day := (value >> 17) & 0x1f // 5 bits starting at 17th
hour := (value >> 12) & 0x1f // 5 bits starting at 12th
minute := (value >> 6) & 0x3f // 6 bits starting at 6th
second := value & 0x3f // 6 bits starting at 0th
microSeconds := raw & 0xffffff // 24 lower bits
timeString := fmt.Sprintf("%04d-%02d-%02d %02d:%02d:%02d.%06d", year, month, day, hour, minute, second, microSeconds)
node = ajson.StringNode("", timeString)
case TypeNewDecimal:
decimalData := data[start:end]
precision := decimalData[0]
scale := decimalData[1]
metadata := (uint16(precision) << 8) + uint16(scale)
val, _, err := CellValue(decimalData, 2, TypeNewDecimal, metadata, &querypb.Field{Type: querypb.Type_DECIMAL})
if err != nil {
return nil, err
}
float, err := val.ToFloat64()
if err != nil {
return nil, err
}
node = ajson.NumericNode("", float)
default:
return nil, fmt.Errorf("opaque type %d is not supported yet, data %v", dataType, data[2:])
}
return node, nil
}
func newOpaquePlugin() *opaquePlugin {
oh := &opaquePlugin{
info: &jsonPluginInfo{
name: "Opaque",
types: []jsonDataType{jsonOpaque},
},
}
binlogJSON.register(jsonOpaque, oh)
return oh
}
//endregion
//region string plugin
func init() {
newStringPlugin()
}
type stringPlugin struct {
info *jsonPluginInfo
}
var _ jsonPlugin = (*stringPlugin)(nil)
func (sh stringPlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
size, pos := readVariableLength(data, pos)
node = ajson.StringNode("", string(data[pos:pos+size]))
return node, nil
}
func newStringPlugin() *stringPlugin {
sh := &stringPlugin{
info: &jsonPluginInfo{
name: "String",
types: []jsonDataType{jsonString},
},
}
binlogJSON.register(jsonString, sh)
return sh
}
//endregion
//region array plugin
func init() {
newArrayPlugin()
}
type arrayPlugin struct {
info *jsonPluginInfo
}
var _ jsonPlugin = (*arrayPlugin)(nil)
// arrays are stored thus:
// | type_identifier(one of [2,3]) | elem count | obj size | list of offsets+lengths of values | actual values |
func (ah arrayPlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
jlog("JSON Array %s, len %d", jsonDataTypeToString(uint(typ)), len(data))
var nodes []*ajson.Node
var elem *ajson.Node
var elementCount, size int
large := typ == jsonLargeArray
elementCount, pos = readInt(data, pos, large)
jlog("Array(%t): elem count: %d\n", large, elementCount)
size, pos = readInt(data, pos, large)
jlog("Array(%t): elem count: %d, size:%d\n", large, elementCount, size)
for i := 0; i < elementCount; i++ {
elem, pos, err = getElem(data, pos, large)
if err != nil {
return nil, err
}
nodes = append(nodes, elem)
jlog("Index is %d:%s", i, jsonDataTypeToString(uint(typ)))
}
node = ajson.ArrayNode("", nodes)
return node, nil
}
func newArrayPlugin() *arrayPlugin {
ah := &arrayPlugin{
info: &jsonPluginInfo{
name: "Array",
types: []jsonDataType{jsonSmallArray, jsonLargeArray},
},
}
binlogJSON.register(jsonSmallArray, ah)
binlogJSON.register(jsonLargeArray, ah)
return ah
}
//endregion
//region object plugin
func init() {
newObjectPlugin()
}
type objectPlugin struct {
info *jsonPluginInfo
}
var _ jsonPlugin = (*objectPlugin)(nil)
// objects are stored thus:
// | type_identifier(0/1) | elem count | obj size | list of offsets+lengths of keys | list of offsets+lengths of values | actual keys | actual values |
func (oh objectPlugin) getNode(typ jsonDataType, data []byte, pos int) (node *ajson.Node, err error) {
jlog("JSON Type is %s, len %d", jsonDataTypeToString(uint(typ)), len(data))
// "large" decides number of bytes used to specify element count and total object size: 4 bytes for large, 2 for small
var large = typ == jsonLargeObject
var elementCount int // total number of elements (== keys) in this object map. (element can be another object: recursively handled)
var size int // total size of object
elementCount, pos = readInt(data, pos, large)
size, pos = readInt(data, pos, large)
jlog("Object: elem count: %d, size %d\n", elementCount, size)
keys := make([]string, elementCount) // stores all the keys in this object
for i := 0; i < elementCount; i++ {
var keyOffset int
var keyLength int
keyOffset, pos = readInt(data, pos, large)
keyLength, pos = readInt(data, pos, false) // keyLength is always a 16-bit int
keyOffsetStart := keyOffset + 1
// check that offsets are not out of bounds (can happen only if there is a bug in the parsing code)
if keyOffsetStart >= len(data) || keyOffsetStart+keyLength > len(data) {
log.Errorf("unable to decode object elements")
return nil, fmt.Errorf("unable to decode object elements: %v", data)
}
keys[i] = string(data[keyOffsetStart : keyOffsetStart+keyLength])
}
jlog("Object keys: %+v", keys)
object := make(map[string]*ajson.Node)
var elem *ajson.Node
// get the value for each key
for i := 0; i < elementCount; i++ {
elem, pos, err = getElem(data, pos, large)
if err != nil {
return nil, err
}
object[keys[i]] = elem
jlog("Key is %s:%s", keys[i], jsonDataTypeToString(uint(typ)))
}
node = ajson.ObjectNode("", object)
return node, nil
}
func newObjectPlugin() *objectPlugin {
oh := &objectPlugin{
info: &jsonPluginInfo{
name: "Object",
types: []jsonDataType{jsonSmallObject, jsonLargeObject},
},
}
binlogJSON.register(jsonSmallObject, oh)
binlogJSON.register(jsonLargeObject, oh)
return oh
}
//endregion