// 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 } isWait := false if req != nil && req.URL != nil { ws := req.URL.Query().Get("wait") if len(ws) != 0 { var err error isWait, err = strconv.ParseBool(ws) if err != nil { return nil, nil, fmt.Errorf("wrong wait value %s (%v for %+v)", ws, err, req) } } } var hctx context.Context var hcancel context.CancelFunc if !isWait && c.headerTimeout > 0 { hctx, hcancel = context.WithTimeout(ctx, c.headerTimeout) } else { hctx, hcancel = context.WithCancel(ctx) } 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 }