golang 大文件分割

package main
import (
 "fmt"
 "io/ioutil"
 "math"
 "os"
 "strconv"
)
const chunkSize int64 = 4 << 20
func main() {
 fileInfo, err := os.Stat("test.zip")
 if err != nil {
 fmt.Println(err)
 }
 num := int(math.Ceil(float64(fileInfo.Size()) / float64(chunkSize)))
 fi, err := os.OpenFile("test.zip", os.O_RDONLY, os.ModePerm)
 if err != nil {
 fmt.Println(err)
 return
 }
 b := make([]byte, chunkSize)
 var i int64 = 1
 for ; i <= int64(num); i++ {
 fi.Seek((i-1)*(chunkSize), 0)
 if len(b) > int((fileInfo.Size() - (i-1)*chunkSize)) {
 b = make([]byte, fileInfo.Size()-(i-1)*chunkSize)
 }
 fi.Read(b)
 f, err := os.OpenFile("./"+strconv.Itoa(int(i))+".db", os.O_CREATE|os.O_WRONLY, os.ModePerm)
 if err != nil {
 fmt.Println(err)
 return
 }
 f.Write(b)
 f.Close()
 }
 fi.Close()
 fii, err := os.OpenFile("test.zip", os.O_CREATE|os.O_WRONLY|os.O_APPEND, os.ModePerm)
 if err != nil {
 fmt.Println(err)
 return
 }
 for i := 1; i <= num; i++ {
 f, err := os.OpenFile("./"+strconv.Itoa(int(i))+".db", os.O_RDONLY, os.ModePerm)
 if err != nil {
 fmt.Println(err)
 return
 }
 b, err := ioutil.ReadAll(f)
 if err != nil {
 fmt.Println(err)
 return
 }
 fii.Write(b)
 f.Close()
 }
}

本文来自:开源中国博客

感谢作者:大蓝妹

查看原文:golang 大文件分割

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