Grab downloader

vendor/github.com/cavaliercoder/grab/example_client_test.go

@@ -0,0 +1,95 @@
+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)
+	}
+}