context/ctxhttp: remove Go 1.6 support, use std context

Fixes golang/go#21358

Change-Id: I8f8653df3c1e3c86cc8515a78509a8af03160944
Reviewed-on: https://go-review.googlesource.com/c/149277
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

context/ctxhttp/ctxhttp.go

@@ -2,18 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build go1.7
-
 // Package ctxhttp provides helper functions for performing context-aware HTTP requests.
 package ctxhttp // import "golang.org/x/net/context/ctxhttp"
 
 import (
+	"context"
 	"io"
 	"net/http"
 	"net/url"
 	"strings"
-
-	"golang.org/x/net/context"
 )
 
 // Do sends an HTTP request with the provided http.Client and returns

context/ctxhttp/ctxhttp_17_test.go

-// Copyright 2015 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.
-
-// +build !plan9,go1.7
-
-package ctxhttp
-
-import (
-	"io"
-	"net/http"
-	"net/http/httptest"
-	"testing"
-
-	"context"
-)
-
-func TestGo17Context(t *testing.T) {
-	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		io.WriteString(w, "ok")
-	}))
-	defer ts.Close()
-	ctx := context.Background()
-	resp, err := Get(ctx, http.DefaultClient, ts.URL)
-	if resp == nil || err != nil {
-		t.Fatalf("error received from client: %v %v", err, resp)
-	}
-	resp.Body.Close()
-}

context/ctxhttp/ctxhttp_pre17.go

-// Copyright 2015 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.
-
-// +build !go1.7
-
-package ctxhttp // import "golang.org/x/net/context/ctxhttp"
-
-import (
-	"io"
-	"net/http"
-	"net/url"
-	"strings"
-
-	"golang.org/x/net/context"
-)
-
-func nop() {}
-
-var (
-	testHookContextDoneBeforeHeaders = nop
-	testHookDoReturned               = nop
-	testHookDidBodyClose             = nop
-)
-
-// 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
-	}
-
-	// TODO(djd): Respect any existing value of req.Cancel.
-	cancel := make(chan struct{})
-	req.Cancel = cancel
-
-	type responseAndError struct {
-		resp *http.Response
-		err  error
-	}
-	result := make(chan responseAndError, 1)
-
-	// Make local copies of test hooks closed over by goroutines below.
-	// Prevents data races in tests.
-	testHookDoReturned := testHookDoReturned
-	testHookDidBodyClose := testHookDidBodyClose
-
-	go func() {
-		resp, err := client.Do(req)
-		testHookDoReturned()
-		result <- responseAndError{resp, err}
-	}()
-
-	var resp *http.Response
-
-	select {
-	case <-ctx.Done():
-		testHookContextDoneBeforeHeaders()
-		close(cancel)
-		// Clean up after the goroutine calling client.Do:
-		go func() {
-			if r := <-result; r.resp != nil {
-				testHookDidBodyClose()
-				r.resp.Body.Close()
-			}
-		}()
-		return nil, ctx.Err()
-	case r := <-result:
-		var err error
-		resp, err = r.resp, r.err
-		if err != nil {
-			return resp, err
-		}
-	}
-
-	c := make(chan struct{})
-	go func() {
-		select {
-		case <-ctx.Done():
-			close(cancel)
-		case <-c:
-			// The response's Body is closed.
-		}
-	}()
-	resp.Body = &notifyingReader{resp.Body, c}
-
-	return resp, nil
-}
-
-// Get issues a GET request via the Do function.
-func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
-	req, err := http.NewRequest("GET", url, nil)
-	if err != nil {
-		return nil, err
-	}
-	return Do(ctx, client, req)
-}
-
-// Head issues a HEAD request via the Do function.
-func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
-	req, err := http.NewRequest("HEAD", url, nil)
-	if err != nil {
-		return nil, err
-	}
-	return Do(ctx, client, req)
-}
-
-// Post issues a POST request via the Do function.
-func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) {
-	req, err := http.NewRequest("POST", url, body)
-	if err != nil {
-		return nil, err
-	}
-	req.Header.Set("Content-Type", bodyType)
-	return Do(ctx, client, req)
-}
-
-// PostForm issues a POST request via the Do function.
-func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) {
-	return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
-}
-
-// notifyingReader is an io.ReadCloser that closes the notify channel after
-// Close is called or a Read fails on the underlying ReadCloser.
-type notifyingReader struct {
-	io.ReadCloser
-	notify chan<- struct{}
-}
-
-func (r *notifyingReader) Read(p []byte) (int, error) {
-	n, err := r.ReadCloser.Read(p)
-	if err != nil && r.notify != nil {
-		close(r.notify)
-		r.notify = nil
-	}
-	return n, err
-}
-
-func (r *notifyingReader) Close() error {
-	err := r.ReadCloser.Close()
-	if r.notify != nil {
-		close(r.notify)
-		r.notify = nil
-	}
-	return err
-}

context/ctxhttp/ctxhttp_pre17_test.go

-// Copyright 2015 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.
-
-// +build !plan9,!go1.7
-
-package ctxhttp
-
-import (
-	"net"
-	"net/http"
-	"net/http/httptest"
-	"sync"
-	"testing"
-	"time"
-
-	"golang.org/x/net/context"
-)
-
-// golang.org/issue/14065
-func TestClosesResponseBodyOnCancel(t *testing.T) {
-	defer func() { testHookContextDoneBeforeHeaders = nop }()
-	defer func() { testHookDoReturned = nop }()
-	defer func() { testHookDidBodyClose = nop }()
-
-	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
-	defer ts.Close()
-
-	ctx, cancel := context.WithCancel(context.Background())
-
-	// closed when Do enters select case <-ctx.Done()
-	enteredDonePath := make(chan struct{})
-
-	testHookContextDoneBeforeHeaders = func() {
-		close(enteredDonePath)
-	}
-
-	testHookDoReturned = func() {
-		// We now have the result (the Flush'd headers) at least,
-		// so we can cancel the request.
-		cancel()
-
-		// But block the client.Do goroutine from sending
-		// until Do enters into the <-ctx.Done() path, since
-		// otherwise if both channels are readable, select
-		// picks a random one.
-		<-enteredDonePath
-	}
-
-	sawBodyClose := make(chan struct{})
-	testHookDidBodyClose = func() { close(sawBodyClose) }
-
-	tr := &http.Transport{}
-	defer tr.CloseIdleConnections()
-	c := &http.Client{Transport: tr}
-	req, _ := http.NewRequest("GET", ts.URL, nil)
-	_, doErr := Do(ctx, c, req)
-
-	select {
-	case <-sawBodyClose:
-	case <-time.After(5 * time.Second):
-		t.Fatal("timeout waiting for body to close")
-	}
-
-	if doErr != ctx.Err() {
-		t.Errorf("Do error = %v; want %v", doErr, ctx.Err())
-	}
-}
-
-type noteCloseConn struct {
-	net.Conn
-	onceClose sync.Once
-	closefn   func()
-}
-
-func (c *noteCloseConn) Close() error {
-	c.onceClose.Do(c.closefn)
-	return c.Conn.Close()
-}

context/ctxhttp/ctxhttp_test.go

@@ -7,16 +7,28 @@
 package ctxhttp
 
 import (
+	"context"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 	"time"
-
-	"golang.org/x/net/context"
 )
 
+func TestGo17Context(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		io.WriteString(w, "ok")
+	}))
+	defer ts.Close()
+	ctx := context.Background()
+	resp, err := Get(ctx, http.DefaultClient, ts.URL)
+	if resp == nil || err != nil {
+		t.Fatalf("error received from client: %v %v", err, resp)
+	}
+	resp.Body.Close()
+}
+
 const (
 	requestDuration = 100 * time.Millisecond
 	requestBody     = "ok"