--- /dev/null
+/*
+Copyright 2013 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package groupcache
+
+import (
+ "errors"
+ "flag"
+ "log"
+ "net"
+ "net/http"
+ "os"
+ "os/exec"
+ "strconv"
+ "strings"
+ "sync"
+ "testing"
+ "time"
+)
+
+var (
+ peerAddrs = flag.String("test_peer_addrs", "", "Comma-separated list of peer addresses; used by TestHTTPPool")
+ peerIndex = flag.Int("test_peer_index", -1, "Index of which peer this child is; used by TestHTTPPool")
+ peerChild = flag.Bool("test_peer_child", false, "True if running as a child process; used by TestHTTPPool")
+)
+
+func TestHTTPPool(t *testing.T) {
+ if *peerChild {
+ beChildForTestHTTPPool()
+ os.Exit(0)
+ }
+
+ const (
+ nChild = 4
+ nGets = 100
+ )
+
+ var childAddr []string
+ for i := 0; i < nChild; i++ {
+ childAddr = append(childAddr, pickFreeAddr(t))
+ }
+
+ var cmds []*exec.Cmd
+ var wg sync.WaitGroup
+ for i := 0; i < nChild; i++ {
+ cmd := exec.Command(os.Args[0],
+ "--test.run=TestHTTPPool",
+ "--test_peer_child",
+ "--test_peer_addrs="+strings.Join(childAddr, ","),
+ "--test_peer_index="+strconv.Itoa(i),
+ )
+ cmds = append(cmds, cmd)
+ wg.Add(1)
+ if err := cmd.Start(); err != nil {
+ t.Fatal("failed to start child process: ", err)
+ }
+ go awaitAddrReady(t, childAddr[i], &wg)
+ }
+ defer func() {
+ for i := 0; i < nChild; i++ {
+ if cmds[i].Process != nil {
+ cmds[i].Process.Kill()
+ }
+ }
+ }()
+ wg.Wait()
+
+ // Use a dummy self address so that we don't handle gets in-process.
+ p := NewHTTPPool("should-be-ignored")
+ p.Set(addrToURL(childAddr)...)
+
+ // Dummy getter function. Gets should go to children only.
+ // The only time this process will handle a get is when the
+ // children can't be contacted for some reason.
+ getter := GetterFunc(func(ctx Context, key string, dest Sink) error {
+ return errors.New("parent getter called; something's wrong")
+ })
+ g := NewGroup("httpPoolTest", 1<<20, getter)
+
+ for _, key := range testKeys(nGets) {
+ var value string
+ if err := g.Get(nil, key, StringSink(&value)); err != nil {
+ t.Fatal(err)
+ }
+ if suffix := ":" + key; !strings.HasSuffix(value, suffix) {
+ t.Errorf("Get(%q) = %q, want value ending in %q", key, value, suffix)
+ }
+ t.Logf("Get key=%q, value=%q (peer:key)", key, value)
+ }
+}
+
+func testKeys(n int) (keys []string) {
+ keys = make([]string, n)
+ for i := range keys {
+ keys[i] = strconv.Itoa(i)
+ }
+ return
+}
+
+func beChildForTestHTTPPool() {
+ addrs := strings.Split(*peerAddrs, ",")
+
+ p := NewHTTPPool("http://" + addrs[*peerIndex])
+ p.Set(addrToURL(addrs)...)
+
+ getter := GetterFunc(func(ctx Context, key string, dest Sink) error {
+ dest.SetString(strconv.Itoa(*peerIndex) + ":" + key)
+ return nil
+ })
+ NewGroup("httpPoolTest", 1<<20, getter)
+
+ log.Fatal(http.ListenAndServe(addrs[*peerIndex], p))
+}
+
+// This is racy. Another process could swoop in and steal the port between the
+// call to this function and the next listen call. Should be okay though.
+// The proper way would be to pass the l.File() as ExtraFiles to the child
+// process, and then close your copy once the child starts.
+func pickFreeAddr(t *testing.T) string {
+ l, err := net.Listen("tcp", "127.0.0.1:0")
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer l.Close()
+ return l.Addr().String()
+}
+
+func addrToURL(addr []string) []string {
+ url := make([]string, len(addr))
+ for i := range addr {
+ url[i] = "http://" + addr[i]
+ }
+ return url
+}
+
+func awaitAddrReady(t *testing.T, addr string, wg *sync.WaitGroup) {
+ defer wg.Done()
+ const max = 1 * time.Second
+ tries := 0
+ for {
+ tries++
+ c, err := net.Dial("tcp", addr)
+ if err == nil {
+ c.Close()
+ return
+ }
+ delay := time.Duration(tries) * 25 * time.Millisecond
+ if delay > max {
+ delay = max
+ }
+ time.Sleep(delay)
+ }
+}
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