// 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
}
}
// Wait blocks until i) the new transport is up or ii) ctx is done or iii) cc is closed.
func (cc *Conn) Wait(ctx context.Context) (transport.ClientTransport, error) {
for {
cc.mu.Lock()
switch {
case cc.state == Shutdown:
cc.mu.Unlock()
return nil, ErrClientConnClosing
case cc.state == Ready:
cc.mu.Unlock()
return cc.transport, nil
default:
ready := cc.ready
if ready == nil {
ready = make(chan struct{})
cc.ready = ready
}
cc.mu.Unlock()
select {
case <-ctx.Done():
return nil, transport.ContextErr(ctx.Err())
// Wait until the new transport is ready or failed.
case <-ready:
}
}
}
}
func (w *watcher) Next(ctx context.Context) (nu []*naming.Update, err error) {
once.Do(func() {
select {
case <-ctx.Done():
err = ctx.Err()
default:
for _, v := range w.kv {
nu = append(nu, &naming.Update{
Op: naming.Add,
Addr: v,
})
}
}
})
if len(nu) > 0 || err != nil {
// once.Do ran. Return directly.
return
}
for {
resp, err := w.wr.Next(ctx)
if err != nil {
return nil, err
}
if resp.Node.Dir {
continue
}
w.mu.Lock()
switch resp.Action {
case "set":
if resp.PrevNode == nil {
nu = append(nu, &naming.Update{
Op: naming.Add,
Addr: resp.Node.Value,
})
w.kv[resp.Node.Key] = resp.Node.Value
} else {
nu = append(nu, &naming.Update{
Op: naming.Delete,
Addr: w.kv[resp.Node.Key],
})
nu = append(nu, &naming.Update{
Op: naming.Add,
Addr: resp.Node.Value,
})
w.kv[resp.Node.Key] = resp.Node.Value
}
case "delete":
nu = append(nu, &naming.Update{
Op: naming.Delete,
Addr: resp.Node.Value,
})
delete(w.kv, resp.Node.Key)
}
w.mu.Unlock()
return nu, nil
}
}
// wait blocks until it can receive from ctx.Done, closing, or proceed.
// If it receives from ctx.Done, it returns 0, the StreamError for ctx.Err.
// If it receives from closing, it returns 0, ErrConnClosing.
// If it receives from proceed, it returns the received integer, nil.
func wait(ctx context.Context, closing <-chan struct{}, proceed <-chan int) (int, error) {
select {
case <-ctx.Done():
return 0, ContextErr(ctx.Err())
case <-closing:
return 0, ErrConnClosing
case i := <-proceed:
return i, nil
}
}