gh-ost/go/mysql/binlog.go

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/*
Copyright 2015 Shlomi Noach, courtesy Booking.com
2016-05-16 09:09:17 +00:00
See https://github.com/github/gh-ost/blob/master/LICENSE
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*/
package mysql
import (
"fmt"
"regexp"
"strconv"
"strings"
)
var detachPattern *regexp.Regexp
func init() {
detachPattern, _ = regexp.Compile(`//([^/:]+):([\d]+)`) // e.g. `//binlog.01234:567890`
}
type BinlogType int
const (
BinaryLog BinlogType = iota
RelayLog
)
// BinlogCoordinates described binary log coordinates in the form of log file & log position.
type BinlogCoordinates struct {
LogFile string
LogPos int64
Type BinlogType
}
// ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306
func ParseBinlogCoordinates(logFileLogPos string) (*BinlogCoordinates, error) {
tokens := strings.SplitN(logFileLogPos, ":", 2)
if len(tokens) != 2 {
return nil, fmt.Errorf("ParseBinlogCoordinates: Cannot parse BinlogCoordinates from %s. Expected format is file:pos", logFileLogPos)
}
if logPos, err := strconv.ParseInt(tokens[1], 10, 0); err != nil {
return nil, fmt.Errorf("ParseBinlogCoordinates: invalid pos: %s", tokens[1])
} else {
return &BinlogCoordinates{LogFile: tokens[0], LogPos: logPos}, nil
}
}
// DisplayString returns a user-friendly string representation of these coordinates
func (this *BinlogCoordinates) DisplayString() string {
return fmt.Sprintf("%s:%d", this.LogFile, this.LogPos)
}
// String returns a user-friendly string representation of these coordinates
func (this BinlogCoordinates) String() string {
return this.DisplayString()
}
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// Equals tests equality of this coordinate and another one.
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func (this *BinlogCoordinates) Equals(other *BinlogCoordinates) bool {
if other == nil {
return false
}
return this.LogFile == other.LogFile && this.LogPos == other.LogPos && this.Type == other.Type
}
// IsEmpty returns true if the log file is empty, unnamed
func (this *BinlogCoordinates) IsEmpty() bool {
return this.LogFile == ""
}
// SmallerThan returns true if this coordinate is strictly smaller than the other.
func (this *BinlogCoordinates) SmallerThan(other *BinlogCoordinates) bool {
if this.LogFile < other.LogFile {
return true
}
if this.LogFile == other.LogFile && this.LogPos < other.LogPos {
return true
}
return false
}
// SmallerThanOrEquals returns true if this coordinate is the same or equal to the other one.
// We do NOT compare the type so we can not use this.Equals()
func (this *BinlogCoordinates) SmallerThanOrEquals(other *BinlogCoordinates) bool {
if this.SmallerThan(other) {
return true
}
return this.LogFile == other.LogFile && this.LogPos == other.LogPos // No Type comparison
}