/
helper.go
67 lines (60 loc) · 1.36 KB
/
helper.go
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package util
import (
"bytes"
"compress/zlib"
"crypto/rand"
"fmt"
"io"
)
const (
letters = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-"
)
//随机产生一个字符串,长度自定义
func GenerateRandomString(n int) (string, error) {
bytes, err := generateRandomBytes(n)
if err != nil {
return "", err
}
length := byte(len(letters))
for i, b := range bytes {
bytes[i] = letters[b%length]
}
return string(bytes), nil
}
//zlib压缩
func Compress(data []byte) []byte {
if len(data) == 0 {
return []byte{}
}
var in bytes.Buffer
w := zlib.NewWriter(&in)
w.Write(data)
w.Close() //flush数据
return in.Bytes()
}
//zlib解压
func Decompress(data []byte) []byte {
if len(data) == 0 {
return []byte{}
}
b := bytes.NewReader(data)
r, err := zlib.NewReader(b)
if err != nil {
fmt.Printf("error decompress: %v\n", err)
return []byte{}
}
defer r.Close()
var out bytes.Buffer
io.Copy(&out, r)
return out.Bytes()
}
//=======================================================
func generateRandomBytes(n int) ([]byte, error) {
b := make([]byte, n)
_, err := rand.Read(b)
// Note that err == nil only if we read len(b) bytes.
if err != nil {
return nil, err
}
return b, nil
}