11
gobox中的shardmap
source link: http://blog.7rule.com/2018/05/25/gobox-shardmap.html
Go to the source link to view the article. You can view the picture content, updated content and better typesetting reading experience. If the link is broken, please click the button below to view the snapshot at that time.
gobox中的shardmap
May 25, 2018
今天来说下gobox中的shardmap。
golang中的map使用简单，但并发写入时，如果不加锁，会导致panic，所以性能很差。
shardmap就是为了解决这个问题，其核心思想就是通过创建多个map，把key做hash分配到这多个map上，从而减少锁粒度以提高性能。
package main
import (
"github.com/goinbox/shardmap"
"github.com/goinbox/crypto"
"fmt"
"strconv"
)
func main() {
shardMap := shardmap.New(32)
hasError:=false
for i := 0; i < 10000; i++ {
key := crypto.Md5String([]byte(strconv.Itoa(i)))
shardMap.Set(key, i)
v, ok := shardMap.Get(key)
if !ok || v != i {
hasError = true
fmt.Println(v, ok)
}
}
if !hasError {
fmt.Println("shardmap set get ok")
}
shardMap.Walk(func(k string, v interface{}) {
shardMap.Del(k)
_, ok := shardMap.Get(k)
if ok {
fmt.Println(v, ok)
}
})
}
输出效果示例
shardmap set get ok
我这里还做了和golang的原生map及sync包中提供的sync.Map的写性能对比：
- 原生map
BenchmarkSimpleMapWrite-4 300000 5935 ns/op
- sync.Map
BenchmarkSyncMapWrite-4 200000 6831 ns/op
- ShardMap
BenchmarkShardMapWrite-4 300000 3815 ns/op
欢迎大家使用，使用中有遇到问题随时反馈，我们会尽快响应，谢谢！
Recommend
About Joyk
Aggregate valuable and interesting links.
Joyk means Joy of geeK