fetch

Documentation

Overview

Package fetch for download, provide high performance download

use Goroutine to parallel download, use WaitGroup to do concurrency control.

Index

• Constants
• Variables
• func GetFileLength(url string) (int64, error)
• func GoroutineDownload(requestURL string, poolSize, chunkSize, timeout int64)

Examples

• GetFileLength

Constants

const (
	FileFlag = os.O_WRONLY | os.O_CREATE
	FileMode = 0644
)

FileFlag save file flag

FileMode save file mode

Variables

var (
	WaitPool = sync.WaitGroup{}
)

WaitPool implement request pool to enhance performance

Functions

func GetFileLength

func GetFileLength(url string) (int64, error)

GetFileLength will return http response content-length example:

GetFileLength("http://xxx")

Example

requestURL := "http://httpbin.org/bytes/%d"

var length1K int64 = 1024
lengthResult, _ := GetFileLength(fmt.Sprintf(requestURL, length1K))
fmt.Println(lengthResult)

Output:

1024

func GoroutineDownload

func GoroutineDownload(requestURL string, poolSize, chunkSize, timeout int64)

GoroutineDownload will download form requestURL. example:

requestURL := "http://xxx"
GoroutineDownload(requestURL, 20, 10*1024*1024, 30)