116 lines
3.3 KiB
Go
116 lines
3.3 KiB
Go
/*
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Copyright 2015 Shlomi Noach, courtesy Booking.com
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See https://github.com/github/gh-ost/blob/master/LICENSE
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*/
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package mysql
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import (
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"fmt"
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"strconv"
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"strings"
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)
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const (
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DefaultInstancePort = 3306
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)
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// InstanceKey is an instance indicator, identifued by hostname and port
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type InstanceKey struct {
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Hostname string
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Port int
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}
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const detachHint = "//"
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// ParseInstanceKey will parse an InstanceKey from a string representation such as 127.0.0.1:3306
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func NewRawInstanceKey(hostPort string) (*InstanceKey, error) {
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tokens := strings.SplitN(hostPort, ":", 2)
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if len(tokens) != 2 {
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return nil, fmt.Errorf("Cannot parse InstanceKey from %s. Expected format is host:port", hostPort)
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}
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instanceKey := &InstanceKey{Hostname: tokens[0]}
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var err error
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if instanceKey.Port, err = strconv.Atoi(tokens[1]); err != nil {
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return instanceKey, fmt.Errorf("Invalid port: %s", tokens[1])
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}
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return instanceKey, nil
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}
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// ParseRawInstanceKeyLoose will parse an InstanceKey from a string representation such as 127.0.0.1:3306.
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// The port part is optional; there will be no name resolve
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func ParseRawInstanceKeyLoose(hostPort string) (*InstanceKey, error) {
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if !strings.Contains(hostPort, ":") {
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return &InstanceKey{Hostname: hostPort, Port: DefaultInstancePort}, nil
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}
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return NewRawInstanceKey(hostPort)
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}
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// Equals tests equality between this key and another key
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func (this *InstanceKey) Equals(other *InstanceKey) bool {
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if other == nil {
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return false
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}
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return this.Hostname == other.Hostname && this.Port == other.Port
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}
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// SmallerThan returns true if this key is dictionary-smaller than another.
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// This is used for consistent sorting/ordering; there's nothing magical about it.
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func (this *InstanceKey) SmallerThan(other *InstanceKey) bool {
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if this.Hostname < other.Hostname {
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return true
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}
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if this.Hostname == other.Hostname && this.Port < other.Port {
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return true
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}
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return false
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}
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// IsDetached returns 'true' when this hostname is logically "detached"
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func (this *InstanceKey) IsDetached() bool {
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return strings.HasPrefix(this.Hostname, detachHint)
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}
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// IsValid uses simple heuristics to see whether this key represents an actual instance
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func (this *InstanceKey) IsValid() bool {
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if this.Hostname == "_" {
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return false
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}
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if this.IsDetached() {
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return false
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}
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return len(this.Hostname) > 0 && this.Port > 0
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}
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// DetachedKey returns an instance key whose hostname is detahced: invalid, but recoverable
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func (this *InstanceKey) DetachedKey() *InstanceKey {
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if this.IsDetached() {
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return this
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}
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return &InstanceKey{Hostname: fmt.Sprintf("%s%s", detachHint, this.Hostname), Port: this.Port}
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}
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// ReattachedKey returns an instance key whose hostname is detahced: invalid, but recoverable
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func (this *InstanceKey) ReattachedKey() *InstanceKey {
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if !this.IsDetached() {
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return this
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}
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return &InstanceKey{Hostname: this.Hostname[len(detachHint):], Port: this.Port}
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}
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// StringCode returns an official string representation of this key
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func (this *InstanceKey) StringCode() string {
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return fmt.Sprintf("%s:%d", this.Hostname, this.Port)
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}
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// DisplayString returns a user-friendly string representation of this key
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func (this *InstanceKey) DisplayString() string {
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return this.StringCode()
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}
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// String returns a user-friendly string representation of this key
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func (this InstanceKey) String() string {
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return this.StringCode()
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}
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