88 lines
2.7 KiB
Go
88 lines
2.7 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package gensupport
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"errors"
|
|
"net/http"
|
|
)
|
|
|
|
// Hook is the type of a function that is called once before each HTTP request
|
|
// that is sent by a generated API. It returns a function that is called after
|
|
// the request returns.
|
|
// Hooks are not called if the context is nil.
|
|
type Hook func(ctx context.Context, req *http.Request) func(resp *http.Response)
|
|
|
|
var hooks []Hook
|
|
|
|
// RegisterHook registers a Hook to be called before each HTTP request by a
|
|
// generated API. Hooks are called in the order they are registered. Each
|
|
// hook can return a function; if it is non-nil, it is called after the HTTP
|
|
// request returns. These functions are called in the reverse order.
|
|
// RegisterHook should not be called concurrently with itself or SendRequest.
|
|
func RegisterHook(h Hook) {
|
|
hooks = append(hooks, h)
|
|
}
|
|
|
|
// SendRequest sends a single HTTP request using the given client.
|
|
// If ctx is non-nil, it calls all hooks, then sends the request with
|
|
// req.WithContext, then calls any functions returned by the hooks in
|
|
// reverse order.
|
|
func SendRequest(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
|
|
// Disallow Accept-Encoding because it interferes with the automatic gzip handling
|
|
// done by the default http.Transport. See https://github.com/google/google-api-go-client/issues/219.
|
|
if _, ok := req.Header["Accept-Encoding"]; ok {
|
|
return nil, errors.New("google api: custom Accept-Encoding headers not allowed")
|
|
}
|
|
if ctx == nil {
|
|
return client.Do(req)
|
|
}
|
|
// Call hooks in order of registration, store returned funcs.
|
|
post := make([]func(resp *http.Response), len(hooks))
|
|
for i, h := range hooks {
|
|
fn := h(ctx, req)
|
|
post[i] = fn
|
|
}
|
|
|
|
// Send request.
|
|
resp, err := send(ctx, client, req)
|
|
|
|
// Call returned funcs in reverse order.
|
|
for i := len(post) - 1; i >= 0; i-- {
|
|
if fn := post[i]; fn != nil {
|
|
fn(resp)
|
|
}
|
|
}
|
|
return resp, err
|
|
}
|
|
|
|
func send(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
|
|
if client == nil {
|
|
client = http.DefaultClient
|
|
}
|
|
resp, err := client.Do(req.WithContext(ctx))
|
|
// If we got an error, and the context has been canceled,
|
|
// the context's error is probably more useful.
|
|
if err != nil {
|
|
select {
|
|
case <-ctx.Done():
|
|
err = ctx.Err()
|
|
default:
|
|
}
|
|
}
|
|
return resp, err
|
|
}
|
|
|
|
// DecodeResponse decodes the body of res into target. If there is no body,
|
|
// target is unchanged.
|
|
func DecodeResponse(target interface{}, res *http.Response) error {
|
|
if res.StatusCode == http.StatusNoContent {
|
|
return nil
|
|
}
|
|
return json.NewDecoder(res.Body).Decode(target)
|
|
}
|