gh-ost/vendor/github.com/siddontang/go-mysql/replication/parser.go

384 lines
9.3 KiB
Go

package replication
import (
"bytes"
"encoding/binary"
"fmt"
"hash/crc32"
"io"
"os"
"sync/atomic"
"time"
"github.com/juju/errors"
)
var (
// ErrChecksumMismatch indicates binlog checksum mismatch.
ErrChecksumMismatch = errors.New("binlog checksum mismatch, data may be corrupted")
)
type BinlogParser struct {
format *FormatDescriptionEvent
tables map[uint64]*TableMapEvent
// for rawMode, we only parse FormatDescriptionEvent and RotateEvent
rawMode bool
parseTime bool
timestampStringLocation *time.Location
// used to start/stop processing
stopProcessing uint32
useDecimal bool
verifyChecksum bool
}
func NewBinlogParser() *BinlogParser {
p := new(BinlogParser)
p.tables = make(map[uint64]*TableMapEvent)
return p
}
func (p *BinlogParser) Stop() {
atomic.StoreUint32(&p.stopProcessing, 1)
}
func (p *BinlogParser) Resume() {
atomic.StoreUint32(&p.stopProcessing, 0)
}
func (p *BinlogParser) Reset() {
p.format = nil
}
type OnEventFunc func(*BinlogEvent) error
func (p *BinlogParser) ParseFile(name string, offset int64, onEvent OnEventFunc) error {
f, err := os.Open(name)
if err != nil {
return errors.Trace(err)
}
defer f.Close()
b := make([]byte, 4)
if _, err = f.Read(b); err != nil {
return errors.Trace(err)
} else if !bytes.Equal(b, BinLogFileHeader) {
return errors.Errorf("%s is not a valid binlog file, head 4 bytes must fe'bin' ", name)
}
if offset < 4 {
offset = 4
} else if offset > 4 {
// FORMAT_DESCRIPTION event should be read by default always (despite that fact passed offset may be higher than 4)
if _, err = f.Seek(4, os.SEEK_SET); err != nil {
return errors.Errorf("seek %s to %d error %v", name, offset, err)
}
if err = p.parseFormatDescriptionEvent(f, onEvent); err != nil {
return errors.Annotatef(err, "parse FormatDescriptionEvent")
}
}
if _, err = f.Seek(offset, os.SEEK_SET); err != nil {
return errors.Errorf("seek %s to %d error %v", name, offset, err)
}
return p.ParseReader(f, onEvent)
}
func (p *BinlogParser) parseFormatDescriptionEvent(r io.Reader, onEvent OnEventFunc) error {
_, err := p.parseSingleEvent(r, onEvent)
return err
}
// ParseSingleEvent parses single binlog event and passes the event to onEvent function.
func (p *BinlogParser) ParseSingleEvent(r io.Reader, onEvent OnEventFunc) (bool, error) {
return p.parseSingleEvent(r, onEvent)
}
func (p *BinlogParser) parseSingleEvent(r io.Reader, onEvent OnEventFunc) (bool, error) {
var err error
var n int64
var buf bytes.Buffer
if n, err = io.CopyN(&buf, r, EventHeaderSize); err == io.EOF {
return true, nil
} else if err != nil {
return false, errors.Errorf("get event header err %v, need %d but got %d", err, EventHeaderSize, n)
}
var h *EventHeader
h, err = p.parseHeader(buf.Bytes())
if err != nil {
return false, errors.Trace(err)
}
if h.EventSize <= uint32(EventHeaderSize) {
return false, errors.Errorf("invalid event header, event size is %d, too small", h.EventSize)
}
if n, err = io.CopyN(&buf, r, int64(h.EventSize-EventHeaderSize)); err != nil {
return false, errors.Errorf("get event err %v, need %d but got %d", err, h.EventSize, n)
}
if buf.Len() != int(h.EventSize) {
return false, errors.Errorf("invalid raw data size in event %s, need %d but got %d", h.EventType, h.EventSize, buf.Len())
}
rawData := buf.Bytes()
bodyLen := int(h.EventSize) - EventHeaderSize
body := rawData[EventHeaderSize:]
if len(body) != bodyLen {
return false, errors.Errorf("invalid body data size in event %s, need %d but got %d", h.EventType, bodyLen, len(body))
}
var e Event
e, err = p.parseEvent(h, body, rawData)
if err != nil {
if err == errMissingTableMapEvent {
return false, nil
}
return false, errors.Trace(err)
}
if err = onEvent(&BinlogEvent{RawData: rawData, Header: h, Event: e}); err != nil {
return false, errors.Trace(err)
}
return false, nil
}
func (p *BinlogParser) ParseReader(r io.Reader, onEvent OnEventFunc) error {
for {
if atomic.LoadUint32(&p.stopProcessing) == 1 {
break
}
done, err := p.parseSingleEvent(r, onEvent)
if err != nil {
if err == errMissingTableMapEvent {
continue
}
return errors.Trace(err)
}
if done {
break
}
}
return nil
}
func (p *BinlogParser) SetRawMode(mode bool) {
p.rawMode = mode
}
func (p *BinlogParser) SetParseTime(parseTime bool) {
p.parseTime = parseTime
}
func (p *BinlogParser) SetTimestampStringLocation(timestampStringLocation *time.Location) {
p.timestampStringLocation = timestampStringLocation
}
func (p *BinlogParser) SetUseDecimal(useDecimal bool) {
p.useDecimal = useDecimal
}
func (p *BinlogParser) SetVerifyChecksum(verify bool) {
p.verifyChecksum = verify
}
func (p *BinlogParser) parseHeader(data []byte) (*EventHeader, error) {
h := new(EventHeader)
err := h.Decode(data)
if err != nil {
return nil, err
}
return h, nil
}
func (p *BinlogParser) parseEvent(h *EventHeader, data []byte, rawData []byte) (Event, error) {
var e Event
if h.EventType == FORMAT_DESCRIPTION_EVENT {
p.format = &FormatDescriptionEvent{}
e = p.format
} else {
if p.format != nil && p.format.ChecksumAlgorithm == BINLOG_CHECKSUM_ALG_CRC32 {
err := p.verifyCrc32Checksum(rawData)
if err != nil {
return nil, err
}
data = data[0 : len(data)-BinlogChecksumLength]
}
if h.EventType == ROTATE_EVENT {
e = &RotateEvent{}
} else if !p.rawMode {
switch h.EventType {
case QUERY_EVENT:
e = &QueryEvent{}
case XID_EVENT:
e = &XIDEvent{}
case TABLE_MAP_EVENT:
te := &TableMapEvent{}
if p.format.EventTypeHeaderLengths[TABLE_MAP_EVENT-1] == 6 {
te.tableIDSize = 4
} else {
te.tableIDSize = 6
}
e = te
case WRITE_ROWS_EVENTv0,
UPDATE_ROWS_EVENTv0,
DELETE_ROWS_EVENTv0,
WRITE_ROWS_EVENTv1,
DELETE_ROWS_EVENTv1,
UPDATE_ROWS_EVENTv1,
WRITE_ROWS_EVENTv2,
UPDATE_ROWS_EVENTv2,
DELETE_ROWS_EVENTv2:
e = p.newRowsEvent(h)
case ROWS_QUERY_EVENT:
e = &RowsQueryEvent{}
case GTID_EVENT:
e = &GTIDEvent{}
case ANONYMOUS_GTID_EVENT:
e = &GTIDEvent{}
case BEGIN_LOAD_QUERY_EVENT:
e = &BeginLoadQueryEvent{}
case EXECUTE_LOAD_QUERY_EVENT:
e = &ExecuteLoadQueryEvent{}
case MARIADB_ANNOTATE_ROWS_EVENT:
e = &MariadbAnnotateRowsEvent{}
case MARIADB_BINLOG_CHECKPOINT_EVENT:
e = &MariadbBinlogCheckPointEvent{}
case MARIADB_GTID_LIST_EVENT:
e = &MariadbGTIDListEvent{}
case MARIADB_GTID_EVENT:
ee := &MariadbGTIDEvent{}
ee.GTID.ServerID = h.ServerID
e = ee
default:
e = &GenericEvent{}
}
} else {
e = &GenericEvent{}
}
}
if err := e.Decode(data); err != nil {
return nil, &EventError{h, err.Error(), data}
}
if te, ok := e.(*TableMapEvent); ok {
p.tables[te.TableID] = te
}
if re, ok := e.(*RowsEvent); ok {
if (re.Flags & RowsEventStmtEndFlag) > 0 {
// Refer https://github.com/alibaba/canal/blob/38cc81b7dab29b51371096fb6763ca3a8432ffee/dbsync/src/main/java/com/taobao/tddl/dbsync/binlog/event/RowsLogEvent.java#L176
p.tables = make(map[uint64]*TableMapEvent)
}
}
return e, nil
}
// Given the bytes for a a binary log event: return the decoded event.
// With the exception of the FORMAT_DESCRIPTION_EVENT event type
// there must have previously been passed a FORMAT_DESCRIPTION_EVENT
// into the parser for this to work properly on any given event.
// Passing a new FORMAT_DESCRIPTION_EVENT into the parser will replace
// an existing one.
func (p *BinlogParser) Parse(data []byte) (*BinlogEvent, error) {
rawData := data
h, err := p.parseHeader(data)
if err != nil {
return nil, err
}
data = data[EventHeaderSize:]
eventLen := int(h.EventSize) - EventHeaderSize
if len(data) != eventLen {
return nil, fmt.Errorf("invalid data size %d in event %s, less event length %d", len(data), h.EventType, eventLen)
}
e, err := p.parseEvent(h, data, rawData)
if err != nil {
return nil, err
}
return &BinlogEvent{RawData: rawData, Header: h, Event: e}, nil
}
func (p *BinlogParser) verifyCrc32Checksum(rawData []byte) error {
if !p.verifyChecksum {
return nil
}
calculatedPart := rawData[0 : len(rawData)-BinlogChecksumLength]
expectedChecksum := rawData[len(rawData)-BinlogChecksumLength:]
// mysql use zlib's CRC32 implementation, which uses polynomial 0xedb88320UL.
// reference: https://github.com/madler/zlib/blob/master/crc32.c
// https://github.com/madler/zlib/blob/master/doc/rfc1952.txt#L419
checksum := crc32.ChecksumIEEE(calculatedPart)
computed := make([]byte, BinlogChecksumLength)
binary.LittleEndian.PutUint32(computed, checksum)
if !bytes.Equal(expectedChecksum, computed) {
return ErrChecksumMismatch
}
return nil
}
func (p *BinlogParser) newRowsEvent(h *EventHeader) *RowsEvent {
e := &RowsEvent{}
if p.format.EventTypeHeaderLengths[h.EventType-1] == 6 {
e.tableIDSize = 4
} else {
e.tableIDSize = 6
}
e.needBitmap2 = false
e.tables = p.tables
e.parseTime = p.parseTime
e.timestampStringLocation = p.timestampStringLocation
e.useDecimal = p.useDecimal
switch h.EventType {
case WRITE_ROWS_EVENTv0:
e.Version = 0
case UPDATE_ROWS_EVENTv0:
e.Version = 0
case DELETE_ROWS_EVENTv0:
e.Version = 0
case WRITE_ROWS_EVENTv1:
e.Version = 1
case DELETE_ROWS_EVENTv1:
e.Version = 1
case UPDATE_ROWS_EVENTv1:
e.Version = 1
e.needBitmap2 = true
case WRITE_ROWS_EVENTv2:
e.Version = 2
case UPDATE_ROWS_EVENTv2:
e.Version = 2
e.needBitmap2 = true
case DELETE_ROWS_EVENTv2:
e.Version = 2
}
return e
}