David K. Bainbridge | 215e024 | 2017-09-05 23:18:24 -0700 | [diff] [blame^] | 1 | // Copyright 2015 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // +build !go1.7 |
| 6 | |
| 7 | package ctxhttp // import "golang.org/x/net/context/ctxhttp" |
| 8 | |
| 9 | import ( |
| 10 | "io" |
| 11 | "net/http" |
| 12 | "net/url" |
| 13 | "strings" |
| 14 | |
| 15 | "golang.org/x/net/context" |
| 16 | ) |
| 17 | |
| 18 | func nop() {} |
| 19 | |
| 20 | var ( |
| 21 | testHookContextDoneBeforeHeaders = nop |
| 22 | testHookDoReturned = nop |
| 23 | testHookDidBodyClose = nop |
| 24 | ) |
| 25 | |
| 26 | // Do sends an HTTP request with the provided http.Client and returns an HTTP response. |
| 27 | // If the client is nil, http.DefaultClient is used. |
| 28 | // If the context is canceled or times out, ctx.Err() will be returned. |
| 29 | func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) { |
| 30 | if client == nil { |
| 31 | client = http.DefaultClient |
| 32 | } |
| 33 | |
| 34 | // TODO(djd): Respect any existing value of req.Cancel. |
| 35 | cancel := make(chan struct{}) |
| 36 | req.Cancel = cancel |
| 37 | |
| 38 | type responseAndError struct { |
| 39 | resp *http.Response |
| 40 | err error |
| 41 | } |
| 42 | result := make(chan responseAndError, 1) |
| 43 | |
| 44 | // Make local copies of test hooks closed over by goroutines below. |
| 45 | // Prevents data races in tests. |
| 46 | testHookDoReturned := testHookDoReturned |
| 47 | testHookDidBodyClose := testHookDidBodyClose |
| 48 | |
| 49 | go func() { |
| 50 | resp, err := client.Do(req) |
| 51 | testHookDoReturned() |
| 52 | result <- responseAndError{resp, err} |
| 53 | }() |
| 54 | |
| 55 | var resp *http.Response |
| 56 | |
| 57 | select { |
| 58 | case <-ctx.Done(): |
| 59 | testHookContextDoneBeforeHeaders() |
| 60 | close(cancel) |
| 61 | // Clean up after the goroutine calling client.Do: |
| 62 | go func() { |
| 63 | if r := <-result; r.resp != nil { |
| 64 | testHookDidBodyClose() |
| 65 | r.resp.Body.Close() |
| 66 | } |
| 67 | }() |
| 68 | return nil, ctx.Err() |
| 69 | case r := <-result: |
| 70 | var err error |
| 71 | resp, err = r.resp, r.err |
| 72 | if err != nil { |
| 73 | return resp, err |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | c := make(chan struct{}) |
| 78 | go func() { |
| 79 | select { |
| 80 | case <-ctx.Done(): |
| 81 | close(cancel) |
| 82 | case <-c: |
| 83 | // The response's Body is closed. |
| 84 | } |
| 85 | }() |
| 86 | resp.Body = ¬ifyingReader{resp.Body, c} |
| 87 | |
| 88 | return resp, nil |
| 89 | } |
| 90 | |
| 91 | // Get issues a GET request via the Do function. |
| 92 | func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) { |
| 93 | req, err := http.NewRequest("GET", url, nil) |
| 94 | if err != nil { |
| 95 | return nil, err |
| 96 | } |
| 97 | return Do(ctx, client, req) |
| 98 | } |
| 99 | |
| 100 | // Head issues a HEAD request via the Do function. |
| 101 | func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) { |
| 102 | req, err := http.NewRequest("HEAD", url, nil) |
| 103 | if err != nil { |
| 104 | return nil, err |
| 105 | } |
| 106 | return Do(ctx, client, req) |
| 107 | } |
| 108 | |
| 109 | // Post issues a POST request via the Do function. |
| 110 | func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) { |
| 111 | req, err := http.NewRequest("POST", url, body) |
| 112 | if err != nil { |
| 113 | return nil, err |
| 114 | } |
| 115 | req.Header.Set("Content-Type", bodyType) |
| 116 | return Do(ctx, client, req) |
| 117 | } |
| 118 | |
| 119 | // PostForm issues a POST request via the Do function. |
| 120 | func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) { |
| 121 | return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode())) |
| 122 | } |
| 123 | |
| 124 | // notifyingReader is an io.ReadCloser that closes the notify channel after |
| 125 | // Close is called or a Read fails on the underlying ReadCloser. |
| 126 | type notifyingReader struct { |
| 127 | io.ReadCloser |
| 128 | notify chan<- struct{} |
| 129 | } |
| 130 | |
| 131 | func (r *notifyingReader) Read(p []byte) (int, error) { |
| 132 | n, err := r.ReadCloser.Read(p) |
| 133 | if err != nil && r.notify != nil { |
| 134 | close(r.notify) |
| 135 | r.notify = nil |
| 136 | } |
| 137 | return n, err |
| 138 | } |
| 139 | |
| 140 | func (r *notifyingReader) Close() error { |
| 141 | err := r.ReadCloser.Close() |
| 142 | if r.notify != nil { |
| 143 | close(r.notify) |
| 144 | r.notify = nil |
| 145 | } |
| 146 | return err |
| 147 | } |