github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/pkg/gtid/gtid.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  package gtid
    15  
    16  import (
    17  	"strings"
    18  
    19  	"github.com/go-mysql-org/go-mysql/mysql"
    20  	"github.com/pingcap/tiflow/dm/pkg/terror"
    21  )
    22  
    23  var (
    24  	emptyMySQLGTIDSet, _   = mysql.ParseMysqlGTIDSet("")
    25  	emptyMariaDBGTIDSet, _ = mysql.ParseMariadbGTIDSet("")
    26  )
    27  
    28  // CheckGTIDSetEmpty is used to check whether a GTID set is zero.
    29  func CheckGTIDSetEmpty(gSet mysql.GTIDSet) bool {
    30  	return gSet == nil || gSet.Equal(emptyMySQLGTIDSet) || gSet.Equal(emptyMariaDBGTIDSet)
    31  }
    32  
    33  // ParserGTID parses GTID from string. If the flavor is not specified, it will
    34  // try mysql GTID first and then MariaDB GTID.
    35  func ParserGTID(flavor, gtidStr string) (mysql.GTIDSet, error) {
    36  	var (
    37  		err  error
    38  		gtid mysql.GTIDSet
    39  	)
    40  
    41  	if len(flavor) == 0 && len(gtidStr) == 0 {
    42  		// regard as mysql, mariadb always enabled gtid
    43  		return mysql.ParseGTIDSet(mysql.MySQLFlavor, "")
    44  	}
    45  
    46  	fla := flavor
    47  	switch fla {
    48  	case mysql.MySQLFlavor:
    49  		if IsZeroMySQLGTIDSet(gtidStr) {
    50  			gtid, err = mysql.ParseGTIDSet(fla, "")
    51  		} else {
    52  			gtid, err = mysql.ParseGTIDSet(fla, gtidStr)
    53  		}
    54  	case mysql.MariaDBFlavor:
    55  		if IsZeroMariaDBGTIDSet(gtidStr) {
    56  			gtid, err = mysql.ParseGTIDSet(fla, "")
    57  		} else {
    58  			gtid, err = mysql.ParseGTIDSet(fla, gtidStr)
    59  		}
    60  	case "":
    61  		fla = mysql.MySQLFlavor
    62  		gtid, err = mysql.ParseGTIDSet(fla, gtidStr)
    63  		if err != nil {
    64  			fla = mysql.MariaDBFlavor
    65  			gtid, err = mysql.ParseGTIDSet(fla, gtidStr)
    66  		}
    67  	default:
    68  		err = terror.ErrNotSupportedFlavor.Generate(flavor)
    69  	}
    70  
    71  	return gtid, err
    72  }
    73  
    74  // ZeroGTIDSet returns an empty GTID set. The flavor must be specified.
    75  func ZeroGTIDSet(flavor string) (mysql.GTIDSet, error) {
    76  	return ParserGTID(flavor, "")
    77  }
    78  
    79  // MustZeroGTIDSet is used when you can make sure the flavor is valid.
    80  func MustZeroGTIDSet(flavor string) mysql.GTIDSet {
    81  	gtid, err := ZeroGTIDSet(flavor)
    82  	if err != nil {
    83  		panic(err)
    84  	}
    85  	return gtid
    86  }
    87  
    88  // IsZeroMySQLGTIDSet is used to meet this usage: when user wants to start binlog
    89  // replication from scratch, a "uuid:0" (MySQL flavor) or "0-0-0" (mariaDB) GTID
    90  // set must be written, in order to distinguish that user forgets to write it.
    91  func IsZeroMySQLGTIDSet(gStr string) bool {
    92  	sp := strings.Split(gStr, ",")
    93  	if len(sp) != 1 {
    94  		return false
    95  	}
    96  
    97  	sep := strings.Split(sp[0], ":")
    98  	if len(sep) != 2 {
    99  		return false
   100  	}
   101  	interval := strings.TrimSpace(sep[1])
   102  	return interval == "0"
   103  }
   104  
   105  // IsZeroMariaDBGTIDSet is used to meet this usage: when user wants to start binlog
   106  // replication from scratch, a "uuid:0" (MySQL flavor) or "0-0-0" (mariaDB) GTID
   107  // set must be written, in order to distinguish that user forgets to write it.
   108  //
   109  // For MariaDB, the GTID set like "0-0-0" will confuse IsZeroGTIDSet function,
   110  // so we also need to check the interval part.
   111  func IsZeroMariaDBGTIDSet(gStr string) bool {
   112  	sp := strings.Split(gStr, ",")
   113  	if len(sp) != 1 {
   114  		return false
   115  	}
   116  
   117  	sep := strings.Split(sp[0], "-")
   118  	if len(sep) != 3 {
   119  		return false
   120  	}
   121  	interval := strings.TrimSpace(sep[2])
   122  	return interval == "0"
   123  }