Merge pull request #461 from iamqizhao/master

removed etcd name resolver impl tentatively and revised the naming API …

naming/etcd/etcd.go

@@ -1,157 +0,0 @@
-/*
- *
- * Copyright 2014, Google Inc.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- *
- *     * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *     * Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following disclaimer
- * in the documentation and/or other materials provided with the
- * distribution.
- *     * Neither the name of Google Inc. nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- */
-
-package etcd
-
-import (
-	"sync"
-
-	etcdcl "github.com/coreos/etcd/client"
-	"golang.org/x/net/context"
-	"google.golang.org/grpc/naming"
-)
-
-// getNode builds the key-value map starting from node recursively. It returns the
-// max etcdcl.Node.ModifiedIndex starting from that node.
-func getNode(node *etcdcl.Node, kv map[string]string) uint64 {
-	if !node.Dir {
-		kv[node.Key] = node.Value
-		return node.ModifiedIndex
-	}
-	var max uint64
-	for _, v := range node.Nodes {
-		i := getNode(v, kv)
-		if max < i {
-			max = i
-		}
-	}
-	return max
-}
-
-type resolver struct {
-	kapi etcdcl.KeysAPI
-}
-
-func (r *resolver) Resolve(target string) (naming.Watcher, error) {
-	resp, err := r.kapi.Get(context.Background(), target, &etcdcl.GetOptions{Recursive: true})
-	if err != nil {
-		return nil, err
-	}
-	kv := make(map[string]string)
-	// Record the index in order to avoid missing updates between Get returning and
-	// watch starting.
-	index := getNode(resp.Node, kv)
-	return &watcher{
-		wr: r.kapi.Watcher(target, &etcdcl.WatcherOptions{
-			AfterIndex: index,
-			Recursive:  true}),
-		kv: kv,
-	}, nil
-}
-
-// NewResolver creates an etcd-based naming.Resolver.
-func NewResolver(cfg etcdcl.Config) (naming.Resolver, error) {
-	c, err := etcdcl.New(cfg)
-	if err != nil {
-		return nil, err
-	}
-	return &resolver{
-		kapi: etcdcl.NewKeysAPI(c),
-	}, nil
-}
-
-type watcher struct {
-	wr etcdcl.Watcher
-	mu sync.Mutex
-	kv map[string]string
-}
-
-var once sync.Once
-
-func (w *watcher) Next(ctx context.Context) (nu []*naming.Update, err error) {
-	once.Do(func() {
-		select {
-		case <-ctx.Done():
-			err = ctx.Err()
-		default:
-			for _, v := range w.kv {
-				nu = append(nu, &naming.Update{
-					Op:   naming.Add,
-					Addr: v,
-				})
-			}
-		}
-	})
-	if len(nu) > 0 || err != nil {
-		// once.Do ran. Return directly.
-		return
-	}
-	for {
-		resp, err := w.wr.Next(ctx)
-		if err != nil {
-			return nil, err
-		}
-		if resp.Node.Dir {
-			continue
-		}
-		w.mu.Lock()
-		switch resp.Action {
-		case "set":
-			if resp.PrevNode == nil {
-				nu = append(nu, &naming.Update{
-					Op:   naming.Add,
-					Addr: resp.Node.Value,
-				})
-				w.kv[resp.Node.Key] = resp.Node.Value
-			} else {
-				nu = append(nu, &naming.Update{
-					Op:   naming.Delete,
-					Addr: w.kv[resp.Node.Key],
-				})
-				nu = append(nu, &naming.Update{
-					Op:   naming.Add,
-					Addr: resp.Node.Value,
-				})
-				w.kv[resp.Node.Key] = resp.Node.Value
-			}
-		case "delete":
-			nu = append(nu, &naming.Update{
-				Op:   naming.Delete,
-				Addr: resp.Node.Value,
-			})
-			delete(w.kv, resp.Node.Key)
-		}
-		w.mu.Unlock()
-		return nu, nil
-	}
-}

naming/naming.go

@@ -72,4 +72,6 @@ type Watcher interface {
 	// Next blocks until an update or error happens. It may return one or more
 	// updates. The first call should get the full set of the results.
 	Next(ctx context.Context) ([]*Update, error)
+	// Close closes the Watcher.
+	Close()
 }