forked from p85947160/gitea
119 lines
2.7 KiB
Go
119 lines
2.7 KiB
Go
// Copyright 2017 The Xorm Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package xorm
|
|
|
|
import (
|
|
"math/rand"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
// GroupPolicy is be used by chosing the current slave from slaves
|
|
type GroupPolicy interface {
|
|
Slave(*EngineGroup) *Engine
|
|
}
|
|
|
|
// GroupPolicyHandler should be used when a function is a GroupPolicy
|
|
type GroupPolicyHandler func(*EngineGroup) *Engine
|
|
|
|
// Slave implements the chosen of slaves
|
|
func (h GroupPolicyHandler) Slave(eg *EngineGroup) *Engine {
|
|
return h(eg)
|
|
}
|
|
|
|
// RandomPolicy implmentes randomly chose the slave of slaves
|
|
func RandomPolicy() GroupPolicyHandler {
|
|
var r = rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
return func(g *EngineGroup) *Engine {
|
|
return g.Slaves()[r.Intn(len(g.Slaves()))]
|
|
}
|
|
}
|
|
|
|
// WeightRandomPolicy implmentes randomly chose the slave of slaves
|
|
func WeightRandomPolicy(weights []int) GroupPolicyHandler {
|
|
var rands = make([]int, 0, len(weights))
|
|
for i := 0; i < len(weights); i++ {
|
|
for n := 0; n < weights[i]; n++ {
|
|
rands = append(rands, i)
|
|
}
|
|
}
|
|
var r = rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
|
|
return func(g *EngineGroup) *Engine {
|
|
var slaves = g.Slaves()
|
|
idx := rands[r.Intn(len(rands))]
|
|
if idx >= len(slaves) {
|
|
idx = len(slaves) - 1
|
|
}
|
|
return slaves[idx]
|
|
}
|
|
}
|
|
|
|
// RoundRobinPolicy returns a group policy handler
|
|
func RoundRobinPolicy() GroupPolicyHandler {
|
|
var pos = -1
|
|
var lock sync.Mutex
|
|
return func(g *EngineGroup) *Engine {
|
|
var slaves = g.Slaves()
|
|
|
|
lock.Lock()
|
|
defer lock.Unlock()
|
|
pos++
|
|
if pos >= len(slaves) {
|
|
pos = 0
|
|
}
|
|
|
|
return slaves[pos]
|
|
}
|
|
}
|
|
|
|
// WeightRoundRobinPolicy returns a group policy handler
|
|
func WeightRoundRobinPolicy(weights []int) GroupPolicyHandler {
|
|
var rands = make([]int, 0, len(weights))
|
|
for i := 0; i < len(weights); i++ {
|
|
for n := 0; n < weights[i]; n++ {
|
|
rands = append(rands, i)
|
|
}
|
|
}
|
|
var pos = -1
|
|
var lock sync.Mutex
|
|
|
|
return func(g *EngineGroup) *Engine {
|
|
var slaves = g.Slaves()
|
|
lock.Lock()
|
|
defer lock.Unlock()
|
|
pos++
|
|
if pos >= len(rands) {
|
|
pos = 0
|
|
}
|
|
|
|
idx := rands[pos]
|
|
if idx >= len(slaves) {
|
|
idx = len(slaves) - 1
|
|
}
|
|
return slaves[idx]
|
|
}
|
|
}
|
|
|
|
// LeastConnPolicy implements GroupPolicy, every time will get the least connections slave
|
|
func LeastConnPolicy() GroupPolicyHandler {
|
|
return func(g *EngineGroup) *Engine {
|
|
var slaves = g.Slaves()
|
|
connections := 0
|
|
idx := 0
|
|
for i := 0; i < len(slaves); i++ {
|
|
openConnections := slaves[i].DB().Stats().OpenConnections
|
|
if i == 0 {
|
|
connections = openConnections
|
|
idx = i
|
|
} else if openConnections <= connections {
|
|
connections = openConnections
|
|
idx = i
|
|
}
|
|
}
|
|
return slaves[idx]
|
|
}
|
|
}
|