import (
"crypto/md5"
"encoding/hex"
"encoding/json"
"fmt"
"hash/crc32"
"hash/fnv"
"strconv"
)
//string to hash
//字符串转化为hash值 使用的是 IEEE
func MakeHash(s string) string { const IEEE = 0xedb88320
var IEEETable = crc32.MakeTable(IEEE) //创建IEEE table
hash := fmt.Sprintf("%x", crc32.Checksum([]byte(s), IEEETable)) return hash
}
//字符串转化为hash值
func HashString(encode string) uint64 { hash := fnv.New64()
hash.Write([]byte(encode))
return hash.Sum64()
}
// 制作特征值方法一
func MakeUnique(obj interface{}) string { baseString, _ := json.Marshal(obj)
return strconv.FormatUint(HashString(string(baseString)), 10)
}
// 制作特征值方法二
func MakeMd5(obj interface{}, length int) string { if length > 32 { length = 32
}
h := md5.New()
baseString, _ := json.Marshal(obj)
h.Write([]byte(baseString))
s := hex.EncodeToString(h.Sum(nil))//转化为16进制字符串
return s[:length]
}