1 files changed, 385 insertions, 0 deletions
diff --git a/src/net/http/httptest/server.go b/src/net/http/httptest/server.go
new file mode 100644
index 0000000..f254a49
--- /dev/null
+++ b/src/net/http/httptest/server.go
@@ -0,0 +1,385 @@
+// Copyright 2011 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.
+
+// Implementation of Server
+
+package httptest
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"net/http"
+	"net/http/internal/testcert"
+	"os"
+	"strings"
+	"sync"
+	"time"
+)
+
+// A Server is an HTTP server listening on a system-chosen port on the
+// local loopback interface, for use in end-to-end HTTP tests.
+type Server struct {
+	URL      string // base URL of form http://ipaddr:port with no trailing slash
+	Listener net.Listener
+
+	// EnableHTTP2 controls whether HTTP/2 is enabled
+	// on the server. It must be set between calling
+	// NewUnstartedServer and calling Server.StartTLS.
+	EnableHTTP2 bool
+
+	// TLS is the optional TLS configuration, populated with a new config
+	// after TLS is started. If set on an unstarted server before StartTLS
+	// is called, existing fields are copied into the new config.
+	TLS *tls.Config
+
+	// Config may be changed after calling NewUnstartedServer and
+	// before Start or StartTLS.
+	Config *http.Server
+
+	// certificate is a parsed version of the TLS config certificate, if present.
+	certificate *x509.Certificate
+
+	// wg counts the number of outstanding HTTP requests on this server.
+	// Close blocks until all requests are finished.
+	wg sync.WaitGroup
+
+	mu     sync.Mutex // guards closed and conns
+	closed bool
+	conns  map[net.Conn]http.ConnState // except terminal states
+
+	// client is configured for use with the server.
+	// Its transport is automatically closed when Close is called.
+	client *http.Client
+}
+
+func newLocalListener() net.Listener {
+	if serveFlag != "" {
+		l, err := net.Listen("tcp", serveFlag)
+		if err != nil {
+			panic(fmt.Sprintf("httptest: failed to listen on %v: %v", serveFlag, err))
+		}
+		return l
+	}
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		if l, err = net.Listen("tcp6", "[::1]:0"); err != nil {
+			panic(fmt.Sprintf("httptest: failed to listen on a port: %v", err))
+		}
+	}
+	return l
+}
+
+// When debugging a particular http server-based test,
+// this flag lets you run
+//
+//	go test -run=BrokenTest -httptest.serve=127.0.0.1:8000
+//
+// to start the broken server so you can interact with it manually.
+// We only register this flag if it looks like the caller knows about it
+// and is trying to use it as we don't want to pollute flags and this
+// isn't really part of our API. Don't depend on this.
+var serveFlag string
+
+func init() {
+	if strSliceContainsPrefix(os.Args, "-httptest.serve=") || strSliceContainsPrefix(os.Args, "--httptest.serve=") {
+		flag.StringVar(&serveFlag, "httptest.serve", "", "if non-empty, httptest.NewServer serves on this address and blocks.")
+	}
+}
+
+func strSliceContainsPrefix(v []string, pre string) bool {
+	for _, s := range v {
+		if strings.HasPrefix(s, pre) {
+			return true
+		}
+	}
+	return false
+}
+
+// NewServer starts and returns a new Server.
+// The caller should call Close when finished, to shut it down.
+func NewServer(handler http.Handler) *Server {
+	ts := NewUnstartedServer(handler)
+	ts.Start()
+	return ts
+}
+
+// NewUnstartedServer returns a new Server but doesn't start it.
+//
+// After changing its configuration, the caller should call Start or
+// StartTLS.
+//
+// The caller should call Close when finished, to shut it down.
+func NewUnstartedServer(handler http.Handler) *Server {
+	return &Server{
+		Listener: newLocalListener(),
+		Config:   &http.Server{Handler: handler},
+	}
+}
+
+// Start starts a server from NewUnstartedServer.
+func (s *Server) Start() {
+	if s.URL != "" {
+		panic("Server already started")
+	}
+	if s.client == nil {
+		s.client = &http.Client{Transport: &http.Transport{}}
+	}
+	s.URL = "http://" + s.Listener.Addr().String()
+	s.wrap()
+	s.goServe()
+	if serveFlag != "" {
+		fmt.Fprintln(os.Stderr, "httptest: serving on", s.URL)
+		select {}
+	}
+}
+
+// StartTLS starts TLS on a server from NewUnstartedServer.
+func (s *Server) StartTLS() {
+	if s.URL != "" {
+		panic("Server already started")
+	}
+	if s.client == nil {
+		s.client = &http.Client{Transport: &http.Transport{}}
+	}
+	cert, err := tls.X509KeyPair(testcert.LocalhostCert, testcert.LocalhostKey)
+	if err != nil {
+		panic(fmt.Sprintf("httptest: NewTLSServer: %v", err))
+	}
+
+	existingConfig := s.TLS
+	if existingConfig != nil {
+		s.TLS = existingConfig.Clone()
+	} else {
+		s.TLS = new(tls.Config)
+	}
+	if s.TLS.NextProtos == nil {
+		nextProtos := []string{"http/1.1"}
+		if s.EnableHTTP2 {
+			nextProtos = []string{"h2"}
+		}
+		s.TLS.NextProtos = nextProtos
+	}
+	if len(s.TLS.Certificates) == 0 {
+		s.TLS.Certificates = []tls.Certificate{cert}
+	}
+	s.certificate, err = x509.ParseCertificate(s.TLS.Certificates[0].Certificate[0])
+	if err != nil {
+		panic(fmt.Sprintf("httptest: NewTLSServer: %v", err))
+	}
+	certpool := x509.NewCertPool()
+	certpool.AddCert(s.certificate)
+	s.client.Transport = &http.Transport{
+		TLSClientConfig: &tls.Config{
+			RootCAs: certpool,
+		},
+		ForceAttemptHTTP2: s.EnableHTTP2,
+	}
+	s.Listener = tls.NewListener(s.Listener, s.TLS)
+	s.URL = "https://" + s.Listener.Addr().String()
+	s.wrap()
+	s.goServe()
+}
+
+// NewTLSServer starts and returns a new Server using TLS.
+// The caller should call Close when finished, to shut it down.
+func NewTLSServer(handler http.Handler) *Server {
+	ts := NewUnstartedServer(handler)
+	ts.StartTLS()
+	return ts
+}
+
+type closeIdleTransport interface {
+	CloseIdleConnections()
+}
+
+// Close shuts down the server and blocks until all outstanding
+// requests on this server have completed.
+func (s *Server) Close() {
+	s.mu.Lock()
+	if !s.closed {
+		s.closed = true
+		s.Listener.Close()
+		s.Config.SetKeepAlivesEnabled(false)
+		for c, st := range s.conns {
+			// Force-close any idle connections (those between
+			// requests) and new connections (those which connected
+			// but never sent a request). StateNew connections are
+			// super rare and have only been seen (in
+			// previously-flaky tests) in the case of
+			// socket-late-binding races from the http Client
+			// dialing this server and then getting an idle
+			// connection before the dial completed. There is thus
+			// a connected connection in StateNew with no
+			// associated Request. We only close StateIdle and
+			// StateNew because they're not doing anything. It's
+			// possible StateNew is about to do something in a few
+			// milliseconds, but a previous CL to check again in a
+			// few milliseconds wasn't liked (early versions of
+			// https://golang.org/cl/15151) so now we just
+			// forcefully close StateNew. The docs for Server.Close say
+			// we wait for "outstanding requests", so we don't close things
+			// in StateActive.
+			if st == http.StateIdle || st == http.StateNew {
+				s.closeConn(c)
+			}
+		}
+		// If this server doesn't shut down in 5 seconds, tell the user why.
+		t := time.AfterFunc(5*time.Second, s.logCloseHangDebugInfo)
+		defer t.Stop()
+	}
+	s.mu.Unlock()
+
+	// Not part of httptest.Server's correctness, but assume most
+	// users of httptest.Server will be using the standard
+	// transport, so help them out and close any idle connections for them.
+	if t, ok := http.DefaultTransport.(closeIdleTransport); ok {
+		t.CloseIdleConnections()
+	}
+
+	// Also close the client idle connections.
+	if s.client != nil {
+		if t, ok := s.client.Transport.(closeIdleTransport); ok {
+			t.CloseIdleConnections()
+		}
+	}
+
+	s.wg.Wait()
+}
+
+func (s *Server) logCloseHangDebugInfo() {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	var buf strings.Builder
+	buf.WriteString("httptest.Server blocked in Close after 5 seconds, waiting for connections:\n")
+	for c, st := range s.conns {
+		fmt.Fprintf(&buf, "  %T %p %v in state %v\n", c, c, c.RemoteAddr(), st)
+	}
+	log.Print(buf.String())
+}
+
+// CloseClientConnections closes any open HTTP connections to the test Server.
+func (s *Server) CloseClientConnections() {
+	s.mu.Lock()
+	nconn := len(s.conns)
+	ch := make(chan struct{}, nconn)
+	for c := range s.conns {
+		go s.closeConnChan(c, ch)
+	}
+	s.mu.Unlock()
+
+	// Wait for outstanding closes to finish.
+	//
+	// Out of paranoia for making a late change in Go 1.6, we
+	// bound how long this can wait, since golang.org/issue/14291
+	// isn't fully understood yet. At least this should only be used
+	// in tests.
+	timer := time.NewTimer(5 * time.Second)
+	defer timer.Stop()
+	for i := 0; i < nconn; i++ {
+		select {
+		case <-ch:
+		case <-timer.C:
+			// Too slow. Give up.
+			return
+		}
+	}
+}
+
+// Certificate returns the certificate used by the server, or nil if
+// the server doesn't use TLS.
+func (s *Server) Certificate() *x509.Certificate {
+	return s.certificate
+}
+
+// Client returns an HTTP client configured for making requests to the server.
+// It is configured to trust the server's TLS test certificate and will
+// close its idle connections on Server.Close.
+func (s *Server) Client() *http.Client {
+	return s.client
+}
+
+func (s *Server) goServe() {
+	s.wg.Add(1)
+	go func() {
+		defer s.wg.Done()
+		s.Config.Serve(s.Listener)
+	}()
+}
+
+// wrap installs the connection state-tracking hook to know which
+// connections are idle.
+func (s *Server) wrap() {
+	oldHook := s.Config.ConnState
+	s.Config.ConnState = func(c net.Conn, cs http.ConnState) {
+		s.mu.Lock()
+		defer s.mu.Unlock()
+
+		switch cs {
+		case http.StateNew:
+			if _, exists := s.conns[c]; exists {
+				panic("invalid state transition")
+			}
+			if s.conns == nil {
+				s.conns = make(map[net.Conn]http.ConnState)
+			}
+			// Add c to the set of tracked conns and increment it to the
+			// waitgroup.
+			s.wg.Add(1)
+			s.conns[c] = cs
+			if s.closed {
+				// Probably just a socket-late-binding dial from
+				// the default transport that lost the race (and
+				// thus this connection is now idle and will
+				// never be used).
+				s.closeConn(c)
+			}
+		case http.StateActive:
+			if oldState, ok := s.conns[c]; ok {
+				if oldState != http.StateNew && oldState != http.StateIdle {
+					panic("invalid state transition")
+				}
+				s.conns[c] = cs
+			}
+		case http.StateIdle:
+			if oldState, ok := s.conns[c]; ok {
+				if oldState != http.StateActive {
+					panic("invalid state transition")
+				}
+				s.conns[c] = cs
+			}
+			if s.closed {
+				s.closeConn(c)
+			}
+		case http.StateHijacked, http.StateClosed:
+			// Remove c from the set of tracked conns and decrement it from the
+			// waitgroup, unless it was previously removed.
+			if _, ok := s.conns[c]; ok {
+				delete(s.conns, c)
+				// Keep Close from returning until the user's ConnState hook
+				// (if any) finishes.
+				defer s.wg.Done()
+			}
+		}
+		if oldHook != nil {
+			oldHook(c, cs)
+		}
+	}
+}
+
+// closeConn closes c.
+// s.mu must be held.
+func (s *Server) closeConn(c net.Conn) { s.closeConnChan(c, nil) }
+
+// closeConnChan is like closeConn, but takes an optional channel to receive a value
+// when the goroutine closing c is done.
+func (s *Server) closeConnChan(c net.Conn, done chan<- struct{}) {
+	c.Close()
+	if done != nil {
+		done <- struct{}{}
+	}
+}