KiwiJuicer KiwiJuicer - 3 months ago 14
HTTP Question

Limiting amount of data read in the response to a HTTP GET request

I'm scraping HTML pages and have set up a HTTP client like so:

client := *http.Client{
Transport: &http.Transport{
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
ResponseHeaderTimeout: 10 * time.Second,
},
}


Now when I make GET requests of multiple URLs I don't want to get stuck with URLs that deliver massive amount of data.

response, err := client.Get(page.Url)
checkErr(err)
body, err := ioutil.ReadAll(response.Body)
checkErr(err)
page.Body = string(body)


Is there a way to limit the amount of data (bytes) the GET request accepts from a resource and stops?

Answer

Use an io.LimitedReader

A LimitedReader reads from R but limits the amount of data returned to just N bytes.

limitedReader := &io.LimitedReader{R: response.Body, N: limit}
body, err := ioutil.ReadAll(limitedReader)

or

body, err := ioutil.ReadAll(io.LimitReader(response.Body, limit))