forked from github/gh-ost
/
gomysql_reader.go
165 lines (147 loc) · 5.11 KB
/
gomysql_reader.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
/*
Copyright 2016 GitHub Inc.
See https://github.com/github/gh-ost/blob/master/LICENSE
*/
package binlog
import (
"fmt"
"sync"
"github.com/github/gh-ost/go/base"
"github.com/github/gh-ost/go/mysql"
"github.com/github/gh-ost/go/sql"
"github.com/outbrain/golib/log"
gomysql "github.com/siddontang/go-mysql/mysql"
"github.com/siddontang/go-mysql/replication"
"golang.org/x/net/context"
)
type GoMySQLReader struct {
connectionConfig *mysql.ConnectionConfig
binlogSyncer *replication.BinlogSyncer
binlogStreamer *replication.BinlogStreamer
currentCoordinates mysql.BinlogCoordinates
currentCoordinatesMutex *sync.Mutex
LastAppliedRowsEventHint mysql.BinlogCoordinates
}
func NewGoMySQLReader(migrationContext *base.MigrationContext) (binlogReader *GoMySQLReader, err error) {
binlogReader = &GoMySQLReader{
connectionConfig: migrationContext.InspectorConnectionConfig,
currentCoordinates: mysql.BinlogCoordinates{},
currentCoordinatesMutex: &sync.Mutex{},
binlogSyncer: nil,
binlogStreamer: nil,
}
serverId := uint32(migrationContext.ReplicaServerId)
binlogSyncerConfig := replication.BinlogSyncerConfig{
ServerID: serverId,
Flavor: "mysql",
Host: binlogReader.connectionConfig.Key.Hostname,
Port: uint16(binlogReader.connectionConfig.Key.Port),
User: binlogReader.connectionConfig.User,
Password: binlogReader.connectionConfig.Password,
TLSConfig: binlogReader.connectionConfig.TLSConfig(),
UseDecimal: true,
}
binlogReader.binlogSyncer = replication.NewBinlogSyncer(binlogSyncerConfig)
return binlogReader, err
}
// ConnectBinlogStreamer
func (this *GoMySQLReader) ConnectBinlogStreamer(coordinates mysql.BinlogCoordinates) (err error) {
if coordinates.IsEmpty() {
return log.Errorf("Empty coordinates at ConnectBinlogStreamer()")
}
this.currentCoordinates = coordinates
log.Infof("Connecting binlog streamer at %+v", this.currentCoordinates)
// Start sync with specified binlog file and position
this.binlogStreamer, err = this.binlogSyncer.StartSync(gomysql.Position{this.currentCoordinates.LogFile, uint32(this.currentCoordinates.LogPos)})
return err
}
func (this *GoMySQLReader) GetCurrentBinlogCoordinates() *mysql.BinlogCoordinates {
this.currentCoordinatesMutex.Lock()
defer this.currentCoordinatesMutex.Unlock()
returnCoordinates := this.currentCoordinates
return &returnCoordinates
}
// StreamEvents
func (this *GoMySQLReader) handleRowsEvent(ev *replication.BinlogEvent, rowsEvent *replication.RowsEvent, entriesChannel chan<- *BinlogEntry) error {
if this.currentCoordinates.SmallerThanOrEquals(&this.LastAppliedRowsEventHint) {
log.Debugf("Skipping handled query at %+v", this.currentCoordinates)
return nil
}
dml := ToEventDML(ev.Header.EventType.String())
if dml == NotDML {
return fmt.Errorf("Unknown DML type: %s", ev.Header.EventType.String())
}
for i, row := range rowsEvent.Rows {
if dml == UpdateDML && i%2 == 1 {
// An update has two rows (WHERE+SET)
// We do both at the same time
continue
}
binlogEntry := NewBinlogEntryAt(this.currentCoordinates)
binlogEntry.DmlEvent = NewBinlogDMLEvent(
string(rowsEvent.Table.Schema),
string(rowsEvent.Table.Table),
dml,
)
switch dml {
case InsertDML:
{
binlogEntry.DmlEvent.NewColumnValues = sql.ToColumnValues(row)
}
case UpdateDML:
{
binlogEntry.DmlEvent.WhereColumnValues = sql.ToColumnValues(row)
binlogEntry.DmlEvent.NewColumnValues = sql.ToColumnValues(rowsEvent.Rows[i+1])
}
case DeleteDML:
{
binlogEntry.DmlEvent.WhereColumnValues = sql.ToColumnValues(row)
}
}
// The channel will do the throttling. Whoever is reading from the channel
// decides whether action is taken synchronously (meaning we wait before
// next iteration) or asynchronously (we keep pushing more events)
// In reality, reads will be synchronous
entriesChannel <- binlogEntry
}
this.LastAppliedRowsEventHint = this.currentCoordinates
return nil
}
// StreamEvents
func (this *GoMySQLReader) StreamEvents(canStopStreaming func() bool, entriesChannel chan<- *BinlogEntry) error {
if canStopStreaming() {
return nil
}
for {
if canStopStreaming() {
break
}
ev, err := this.binlogStreamer.GetEvent(context.Background())
if err != nil {
return err
}
func() {
this.currentCoordinatesMutex.Lock()
defer this.currentCoordinatesMutex.Unlock()
this.currentCoordinates.LogPos = int64(ev.Header.LogPos)
}()
if rotateEvent, ok := ev.Event.(*replication.RotateEvent); ok {
func() {
this.currentCoordinatesMutex.Lock()
defer this.currentCoordinatesMutex.Unlock()
this.currentCoordinates.LogFile = string(rotateEvent.NextLogName)
}()
log.Infof("rotate to next log from %s:%d to %s", this.currentCoordinates.LogFile, int64(ev.Header.LogPos), rotateEvent.NextLogName)
} else if rowsEvent, ok := ev.Event.(*replication.RowsEvent); ok {
if err := this.handleRowsEvent(ev, rowsEvent, entriesChannel); err != nil {
return err
}
}
}
log.Debugf("done streaming events")
return nil
}
func (this *GoMySQLReader) Close() error {
this.binlogSyncer.Close()
return nil
}