// Basic usage of a IOThrottlerPool to throttle reading from a file
func ExampleIOThrottlerPool() {
// Construct a bandwidth throttling pool that's limited to 100 bytes per second
pool := iothrottler.NewIOThrottlerPool(iothrottler.BytesPerSecond * 100)
defer pool.ReleasePool()
file, err := os.Open("/dev/zero")
if err != nil {
// handle error
return
}
defer file.Close()
throttledFile, err := pool.AddReader(file)
if err != nil {
// handle error
return
}
var zeros bytes.Buffer
copied, err := io.CopyN(&zeros, throttledFile, 200)
if err != nil {
// handle error
}
fmt.Printf("Copied %v bytes\n", copied)
// Output: Copied 200 bytes
}
// Throttle web requests using an IOThrottlerPool
func ExampleIOThrottlerPool_AddConn() {
// Construct a bandwidth throttling pool that's limited to 30 kilobits per
// second
pool := iothrottler.NewIOThrottlerPool(iothrottler.Kbps * 30)
defer pool.ReleasePool()
// Create our own Dial function that will be used for the http connection
throttledDial := func(nt, addr string) (c net.Conn, err error) {
conn, err := net.Dial(nt, addr)
if err != nil {
return nil, err
}
return pool.AddConn(conn)
}
// Create a transport that will use our throttled Dial function
tr := &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: throttledDial,
}
// Download the page
client := &http.Client{Transport: tr}
resp, err := client.Get("http://www.google.com")
if err != nil {
// handle error
return
}
defer resp.Body.Close()
// Read the entire contents of the body
_, err = ioutil.ReadAll(resp.Body)
if err != nil {
// handle error
return
}
fmt.Println("Downloaded www.google.com")
// Output: Downloaded www.google.com
}
