github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/pkg/binlog/event/sid_mysql.go (about)

     1  // Copyright 2019 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  // binlog events generator for MySQL used to generate some binlog events for tests.
    15  // Readability takes precedence over performance.
    16  
    17  package event
    18  
    19  import (
    20  	"encoding/hex"
    21  
    22  	"github.com/go-mysql-org/go-mysql/replication"
    23  	"github.com/pingcap/tiflow/dm/pkg/terror"
    24  )
    25  
    26  // SID represents a SERVER_UUID in GTIDEvent/PrevGTIDEvent.
    27  type SID [replication.SidLength]byte
    28  
    29  // Bytes returns the byte slices representation of SID.
    30  func (sid SID) Bytes() []byte {
    31  	return sid[:]
    32  }
    33  
    34  func (sid SID) String() string {
    35  	dst := []byte("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx")
    36  	hex.Encode(dst, sid[:4])
    37  	hex.Encode(dst[9:], sid[4:6])
    38  	hex.Encode(dst[14:], sid[6:8])
    39  	hex.Encode(dst[19:], sid[8:10])
    40  	hex.Encode(dst[24:], sid[10:16])
    41  	return string(dst)
    42  }
    43  
    44  // ParseSID parses a SID from its string representation.
    45  // ref https://github.com/vitessio/vitess/blob/869543aa2c4c467f146ba7d77f6d090ca7f8a862/go/mysql/mysql56_gtid.go#L66.
    46  func ParseSID(s string) (SID, error) {
    47  	var sid SID
    48  	if len(s) != 36 || s[8] != '-' || s[13] != '-' || s[18] != '-' || s[23] != '-' {
    49  		return sid, terror.ErrBinlogParseSID.Generatef("SID string %s not valid", s)
    50  	}
    51  
    52  	// drop the dashes so we can just check the error of Decode once.
    53  	b := make([]byte, 0, 32)
    54  	b = append(b, s[:8]...)
    55  	b = append(b, s[9:13]...)
    56  	b = append(b, s[14:18]...)
    57  	b = append(b, s[19:23]...)
    58  	b = append(b, s[24:]...)
    59  
    60  	if _, err := hex.Decode(sid[:], b); err != nil {
    61  		return sid, terror.ErrBinlogParseSID.SetMessage("decode % X").Delegate(err, b)
    62  	}
    63  	return sid, nil
    64  }