// Do sends an HTTP request with the provided http.Client and returns an HTTP response.
// If the client is nil, http.DefaultClient is used.
// If the context is canceled or times out, ctx.Err() will be returned.
func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
if client == nil {
client = http.DefaultClient
}
// Request cancelation changed in Go 1.5, see cancelreq.go and cancelreq_go14.go.
cancel := canceler(client, req)
type responseAndError struct {
resp *http.Response
err error
}
result := make(chan responseAndError, 1)
go func() {
resp, err := client.Do(req)
result <- responseAndError{resp, err}
}()
select {
case <-ctx.Done():
cancel()
return nil, ctx.Err()
case r := <-result:
return r.resp, r.err
}
}
func (c *httpClusterClient) AutoSync(ctx context.Context, interval time.Duration) error {
ticker := time.NewTicker(interval)
defer ticker.Stop()
for {
err := c.Sync(ctx)
if err != nil {
return err
}
select {
case <-ctx.Done():
return ctx.Err()
case <-ticker.C:
}
}
}
func (c *simpleHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
req := act.HTTPRequest(c.endpoint)
if err := printcURL(req); err != nil {
return nil, nil, err
}
hctx, hcancel := context.WithCancel(ctx)
if c.headerTimeout > 0 {
hctx, hcancel = context.WithTimeout(ctx, c.headerTimeout)
}
defer hcancel()
reqcancel := requestCanceler(c.transport, req)
rtchan := make(chan roundTripResponse, 1)
go func() {
resp, err := c.transport.RoundTrip(req)
rtchan <- roundTripResponse{resp: resp, err: err}
close(rtchan)
}()
var resp *http.Response
var err error
select {
case rtresp := <-rtchan:
resp, err = rtresp.resp, rtresp.err
case <-hctx.Done():
// cancel and wait for request to actually exit before continuing
reqcancel()
rtresp := <-rtchan
resp = rtresp.resp
switch {
case ctx.Err() != nil:
err = ctx.Err()
case hctx.Err() != nil:
err = fmt.Errorf("client: endpoint %s exceeded header timeout", c.endpoint.String())
default:
panic("failed to get error from context")
}
}
// always check for resp nil-ness to deal with possible
// race conditions between channels above
defer func() {
if resp != nil {
resp.Body.Close()
}
}()
if err != nil {
return nil, nil, err
}
var body []byte
done := make(chan struct{})
go func() {
body, err = ioutil.ReadAll(resp.Body)
done <- struct{}{}
}()
select {
case <-ctx.Done():
resp.Body.Close()
<-done
return nil, nil, ctx.Err()
case <-done:
}
return resp, body, err
}