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golang 中没有队列这种数据结构,通常须要本人实现,常见的能够通过 list 或 slice 实现。
go 队列的实现形式
list 是 ”container/list” 中的数据结构,用双向链表实现,能够用来做队列:
// 入队
func (l *List) PushBack(v interface{}) *Element
// 出队:先 Front() 获得头,而后 Remove() 删除
func (l *List) Front() *Element
func (l *List) Remove(e *Element) interface{}
slice 实现队列的形式:
var s []obj
s = append(s, obj) // 入队
s = s[1:] // 出队
benchmark 测试比拟
benchmark 测试代码: 队列中存入 object 对象
type EventMsg struct {
Id string
Msg string
}
func BenchmarkQueue_ListObject(b *testing.B) {var l = list.New()
for i := 0; i < b.N; i++ {
l.PushBack(EventMsg{Id: strconv.Itoa(i),
Msg: "1:abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz",
})
l.PushBack(EventMsg{Id: strconv.Itoa(i),
Msg: "1:opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn",
})
l.Remove(l.Front())
}
}
func BenchmarkQueue_SliceObject(b *testing.B) {var q []EventMsg
for i := 0; i < b.N; i++ {
q = append(q, EventMsg{Id: strconv.Itoa(i),
Msg: "1:abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz",
})
q = append(q, EventMsg{Id: strconv.Itoa(i),
Msg: "1:opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn",
})
q = q[1:]
}
}
benchmark 测试代码:队列中存入 Object 指针对象
func BenchmarkQueue_ListObjPtr(b *testing.B) {var l = list.New()
for i := 0; i < b.N; i++ {
l.PushBack(&EventMsg{Id: strconv.Itoa(i),
Msg: "1:abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz",
})
l.PushBack(&EventMsg{Id: strconv.Itoa(i),
Msg: "1:opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn",
})
l.Remove(l.Front())
}
}
func BenchmarkQueue_SliceObjPtr(b *testing.B) {var q []*EventMsg
for i := 0; i < b.N; i++ {
q = append(q, &EventMsg{Id: strconv.Itoa(i),
Msg: "1:abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz-abcdefghijklmnopqrstuvwxyz",
})
q = append(q, &EventMsg{Id: strconv.Itoa(i),
Msg: "1:opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn-opqrstuvwxyzabcdefghijklmn",
})
q = q[1:]
}
}
benchmark 测试后果
# go test -bench=BenchmarkQueue -count=1 -benchmem -cpu 4
BenchmarkQueue_ListObject-4 1000000 1423 ns/op 175 B/op 5 allocs/op
BenchmarkQueue_ListObjPtr-4 1000000 1124 ns/op 175 B/op 5 allocs/op
BenchmarkQueue_SliceObject-4 1000000 1574 ns/op 357 B/op 1 allocs/op
BenchmarkQueue_SliceObjPtr-4 1831449 662.7 ns/op 161 B/op 3 allocs/op
PASS
ok github.com/go_list/bench_test 6.144s
论断:
- 不论用 list 还是 slice,队列中存储对象指针的性能,要好于间接存储对象;
- slice 实现的队列,存储指针对象时性能最好;
- list 实现的队列,不论是存储对象还是指针对象,其性能差别不是太大;
Open-falcon 的队列实现
open-falcon 应用 list 和 mutex 实现了一个协程平安的内存队列。
实现代码:https://github.com/toolkits/c…
type SafeList struct {
sync.RWMutex
L *list.List
}
func NewSafeList() *SafeList {return &SafeList{L: list.New()}
}
// 入队
func (this *SafeList) PushFront(v interface{}) *list.Element {this.Lock()
e := this.L.PushFront(v)
this.Unlock()
return e
}
// 出队
func (this *SafeList) PopBack() interface{} {this.Lock()
if elem := this.L.Back(); elem != nil {item := this.L.Remove(elem)
this.Unlock()
return item
}
this.Unlock()
return nil
}
参考:
1.https://blog.wolfogre.com/pos…
正文完