gloader/grab/example_client_test.go
2020-12-09 13:29:14 -08:00

96 lines
2.0 KiB
Go

package grab
import (
"fmt"
"sync"
)
func ExampleClient_Do() {
client := NewClient()
req, err := NewRequest("/tmp", "http://example.com/example.zip")
if err != nil {
panic(err)
}
resp := client.Do(req)
if err := resp.Err(); err != nil {
panic(err)
}
fmt.Println("Download saved to", resp.Filename)
}
// This example uses DoChannel to create a Producer/Consumer model for
// downloading multiple files concurrently. This is similar to how DoBatch uses
// DoChannel under the hood except that it allows the caller to continually send
// new requests until they wish to close the request channel.
func ExampleClient_DoChannel() {
// create a request and a buffered response channel
reqch := make(chan *Request)
respch := make(chan *Response, 10)
// start 4 workers
client := NewClient()
wg := sync.WaitGroup{}
for i := 0; i < 4; i++ {
wg.Add(1)
go func() {
client.DoChannel(reqch, respch)
wg.Done()
}()
}
go func() {
// send requests
for i := 0; i < 10; i++ {
url := fmt.Sprintf("http://example.com/example%d.zip", i+1)
req, err := NewRequest("/tmp", url)
if err != nil {
panic(err)
}
reqch <- req
}
close(reqch)
// wait for workers to finish
wg.Wait()
close(respch)
}()
// check each response
for resp := range respch {
// block until complete
if err := resp.Err(); err != nil {
panic(err)
}
fmt.Printf("Downloaded %s to %s\n", resp.Request.URL(), resp.Filename)
}
}
func ExampleClient_DoBatch() {
// create multiple download requests
reqs := make([]*Request, 0)
for i := 0; i < 10; i++ {
url := fmt.Sprintf("http://example.com/example%d.zip", i+1)
req, err := NewRequest("/tmp", url)
if err != nil {
panic(err)
}
reqs = append(reqs, req)
}
// start downloads with 4 workers
client := NewClient()
respch := client.DoBatch(4, reqs...)
// check each response
for resp := range respch {
if err := resp.Err(); err != nil {
panic(err)
}
fmt.Printf("Downloaded %s to %s\n", resp.Request.URL(), resp.Filename)
}
}