Fix GCS

Signed-off-by: Olivier Gambier <olivier@docker.com>

vendor/google.golang.org/grpc/picker.go

@@ -0,0 +1,243 @@
+/*
+ *
+ * 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 grpc
+
+import (
+	"container/list"
+	"fmt"
+	"sync"
+
+	"golang.org/x/net/context"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/naming"
+	"google.golang.org/grpc/transport"
+)
+
+// Picker picks a Conn for RPC requests.
+// This is EXPERIMENTAL and please do not implement your own Picker for now.
+type Picker interface {
+	// Init does initial processing for the Picker, e.g., initiate some connections.
+	Init(cc *ClientConn) error
+	// Pick blocks until either a transport.ClientTransport is ready for the upcoming RPC
+	// or some error happens.
+	Pick(ctx context.Context) (transport.ClientTransport, error)
+	// PickAddr picks a peer address for connecting. This will be called repeated for
+	// connecting/reconnecting.
+	PickAddr() (string, error)
+	// State returns the connectivity state of the underlying connections.
+	State() (ConnectivityState, error)
+	// WaitForStateChange blocks until the state changes to something other than
+	// the sourceState. It returns the new state or error.
+	WaitForStateChange(ctx context.Context, sourceState ConnectivityState) (ConnectivityState, error)
+	// Close closes all the Conn's owned by this Picker.
+	Close() error
+}
+
+// unicastPicker is the default Picker which is used when there is no custom Picker
+// specified by users. It always picks the same Conn.
+type unicastPicker struct {
+	target string
+	conn   *Conn
+}
+
+func (p *unicastPicker) Init(cc *ClientConn) error {
+	c, err := NewConn(cc)
+	if err != nil {
+		return err
+	}
+	p.conn = c
+	return nil
+}
+
+func (p *unicastPicker) Pick(ctx context.Context) (transport.ClientTransport, error) {
+	return p.conn.Wait(ctx)
+}
+
+func (p *unicastPicker) PickAddr() (string, error) {
+	return p.target, nil
+}
+
+func (p *unicastPicker) State() (ConnectivityState, error) {
+	return p.conn.State(), nil
+}
+
+func (p *unicastPicker) WaitForStateChange(ctx context.Context, sourceState ConnectivityState) (ConnectivityState, error) {
+	return p.conn.WaitForStateChange(ctx, sourceState)
+}
+
+func (p *unicastPicker) Close() error {
+	if p.conn != nil {
+		return p.conn.Close()
+	}
+	return nil
+}
+
+// unicastNamingPicker picks an address from a name resolver to set up the connection.
+type unicastNamingPicker struct {
+	cc       *ClientConn
+	resolver naming.Resolver
+	watcher  naming.Watcher
+	mu       sync.Mutex
+	// The list of the addresses are obtained from watcher.
+	addrs *list.List
+	// It tracks the current picked addr by PickAddr(). The next PickAddr may
+	// push it forward on addrs.
+	pickedAddr *list.Element
+	conn       *Conn
+}
+
+// NewUnicastNamingPicker creates a Picker to pick addresses from a name resolver
+// to connect.
+func NewUnicastNamingPicker(r naming.Resolver) Picker {
+	return &unicastNamingPicker{
+		resolver: r,
+		addrs:    list.New(),
+	}
+}
+
+type addrInfo struct {
+	addr string
+	// Set to true if this addrInfo needs to be deleted in the next PickAddrr() call.
+	deleting bool
+}
+
+// processUpdates calls Watcher.Next() once and processes the obtained updates.
+func (p *unicastNamingPicker) processUpdates() error {
+	updates, err := p.watcher.Next()
+	if err != nil {
+		return err
+	}
+	for _, update := range updates {
+		switch update.Op {
+		case naming.Add:
+			p.mu.Lock()
+			p.addrs.PushBack(&addrInfo{
+				addr: update.Addr,
+			})
+			p.mu.Unlock()
+			// Initial connection setup
+			if p.conn == nil {
+				conn, err := NewConn(p.cc)
+				if err != nil {
+					return err
+				}
+				p.conn = conn
+			}
+		case naming.Delete:
+			p.mu.Lock()
+			for e := p.addrs.Front(); e != nil; e = e.Next() {
+				if update.Addr == e.Value.(*addrInfo).addr {
+					if e == p.pickedAddr {
+						// Do not remove the element now if it is the current picked
+						// one. We leave the deletion to the next PickAddr() call.
+						e.Value.(*addrInfo).deleting = true
+						// Notify Conn to close it. All the live RPCs on this connection
+						// will be aborted.
+						p.conn.NotifyReset()
+					} else {
+						p.addrs.Remove(e)
+					}
+				}
+			}
+			p.mu.Unlock()
+		default:
+			grpclog.Println("Unknown update.Op ", update.Op)
+		}
+	}
+	return nil
+}
+
+// monitor runs in a standalone goroutine to keep watching name resolution updates until the watcher
+// is closed.
+func (p *unicastNamingPicker) monitor() {
+	for {
+		if err := p.processUpdates(); err != nil {
+			return
+		}
+	}
+}
+
+func (p *unicastNamingPicker) Init(cc *ClientConn) error {
+	w, err := p.resolver.Resolve(cc.target)
+	if err != nil {
+		return err
+	}
+	p.watcher = w
+	p.cc = cc
+	// Get the initial name resolution.
+	if err := p.processUpdates(); err != nil {
+		return err
+	}
+	go p.monitor()
+	return nil
+}
+
+func (p *unicastNamingPicker) Pick(ctx context.Context) (transport.ClientTransport, error) {
+	return p.conn.Wait(ctx)
+}
+
+func (p *unicastNamingPicker) PickAddr() (string, error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.pickedAddr == nil {
+		p.pickedAddr = p.addrs.Front()
+	} else {
+		pa := p.pickedAddr
+		p.pickedAddr = pa.Next()
+		if pa.Value.(*addrInfo).deleting {
+			p.addrs.Remove(pa)
+		}
+		if p.pickedAddr == nil {
+			p.pickedAddr = p.addrs.Front()
+		}
+	}
+	if p.pickedAddr == nil {
+		return "", fmt.Errorf("there is no address available to pick")
+	}
+	return p.pickedAddr.Value.(*addrInfo).addr, nil
+}
+
+func (p *unicastNamingPicker) State() (ConnectivityState, error) {
+	return 0, fmt.Errorf("State() is not supported for unicastNamingPicker")
+}
+
+func (p *unicastNamingPicker) WaitForStateChange(ctx context.Context, sourceState ConnectivityState) (ConnectivityState, error) {
+	return 0, fmt.Errorf("WaitForStateChange is not supported for unicastNamingPciker")
+}
+
+func (p *unicastNamingPicker) Close() error {
+	p.watcher.Close()
+	p.conn.Close()
+	return nil
+}