[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/maintenance.go b/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/maintenance.go
new file mode 100644
index 0000000..9c168d7
--- /dev/null
+++ b/vendor/github.com/coreos/etcd/etcdserver/api/v3rpc/maintenance.go
@@ -0,0 +1,258 @@
+// Copyright 2016 The etcd Authors
+//
+// 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 v3rpc
+
+import (
+	"context"
+	"crypto/sha256"
+	"io"
+	"time"
+
+	"github.com/coreos/etcd/auth"
+	"github.com/coreos/etcd/etcdserver"
+	"github.com/coreos/etcd/etcdserver/api/v3rpc/rpctypes"
+	pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
+	"github.com/coreos/etcd/mvcc"
+	"github.com/coreos/etcd/mvcc/backend"
+	"github.com/coreos/etcd/pkg/types"
+	"github.com/coreos/etcd/version"
+	"github.com/dustin/go-humanize"
+)
+
+type KVGetter interface {
+	KV() mvcc.ConsistentWatchableKV
+}
+
+type BackendGetter interface {
+	Backend() backend.Backend
+}
+
+type Alarmer interface {
+	Alarm(ctx context.Context, ar *pb.AlarmRequest) (*pb.AlarmResponse, error)
+}
+
+type LeaderTransferrer interface {
+	MoveLeader(ctx context.Context, lead, target uint64) error
+}
+
+type RaftStatusGetter interface {
+	etcdserver.RaftTimer
+	ID() types.ID
+	Leader() types.ID
+}
+
+type AuthGetter interface {
+	AuthInfoFromCtx(ctx context.Context) (*auth.AuthInfo, error)
+	AuthStore() auth.AuthStore
+}
+
+type maintenanceServer struct {
+	rg  RaftStatusGetter
+	kg  KVGetter
+	bg  BackendGetter
+	a   Alarmer
+	lt  LeaderTransferrer
+	hdr header
+}
+
+func NewMaintenanceServer(s *etcdserver.EtcdServer) pb.MaintenanceServer {
+	srv := &maintenanceServer{rg: s, kg: s, bg: s, a: s, lt: s, hdr: newHeader(s)}
+	return &authMaintenanceServer{srv, s}
+}
+
+func (ms *maintenanceServer) Defragment(ctx context.Context, sr *pb.DefragmentRequest) (*pb.DefragmentResponse, error) {
+	plog.Noticef("starting to defragment the storage backend...")
+	err := ms.bg.Backend().Defrag()
+	if err != nil {
+		plog.Errorf("failed to defragment the storage backend (%v)", err)
+		return nil, err
+	}
+	plog.Noticef("finished defragmenting the storage backend")
+	return &pb.DefragmentResponse{}, nil
+}
+
+// big enough size to hold >1 OS pages in the buffer
+const snapshotSendBufferSize = 32 * 1024
+
+func (ms *maintenanceServer) Snapshot(sr *pb.SnapshotRequest, srv pb.Maintenance_SnapshotServer) error {
+	snap := ms.bg.Backend().Snapshot()
+	pr, pw := io.Pipe()
+
+	defer pr.Close()
+
+	go func() {
+		snap.WriteTo(pw)
+		if err := snap.Close(); err != nil {
+			plog.Errorf("error closing snapshot (%v)", err)
+		}
+		pw.Close()
+	}()
+
+	// record SHA digest of snapshot data
+	// used for integrity checks during snapshot restore operation
+	h := sha256.New()
+
+	// buffer just holds read bytes from stream
+	// response size is multiple of OS page size, fetched in boltdb
+	// e.g. 4*1024
+	buf := make([]byte, snapshotSendBufferSize)
+
+	sent := int64(0)
+	total := snap.Size()
+	size := humanize.Bytes(uint64(total))
+
+	start := time.Now()
+	plog.Infof("sending database snapshot to client %s [%d bytes]", size, total)
+	for total-sent > 0 {
+		n, err := io.ReadFull(pr, buf)
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			return togRPCError(err)
+		}
+		sent += int64(n)
+
+		// if total is x * snapshotSendBufferSize. it is possible that
+		// resp.RemainingBytes == 0
+		// resp.Blob == zero byte but not nil
+		// does this make server response sent to client nil in proto
+		// and client stops receiving from snapshot stream before
+		// server sends snapshot SHA?
+		// No, the client will still receive non-nil response
+		// until server closes the stream with EOF
+
+		resp := &pb.SnapshotResponse{
+			RemainingBytes: uint64(total - sent),
+			Blob:           buf[:n],
+		}
+		if err = srv.Send(resp); err != nil {
+			return togRPCError(err)
+		}
+		h.Write(buf[:n])
+	}
+
+	// send SHA digest for integrity checks
+	// during snapshot restore operation
+	sha := h.Sum(nil)
+
+	plog.Infof("sending database sha256 checksum to client [%d bytes]", len(sha))
+	hresp := &pb.SnapshotResponse{RemainingBytes: 0, Blob: sha}
+	if err := srv.Send(hresp); err != nil {
+		return togRPCError(err)
+	}
+
+	plog.Infof("successfully sent database snapshot to client %s [%d bytes, took %s]", size, total, humanize.Time(start))
+	return nil
+}
+
+func (ms *maintenanceServer) Hash(ctx context.Context, r *pb.HashRequest) (*pb.HashResponse, error) {
+	h, rev, err := ms.kg.KV().Hash()
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+	resp := &pb.HashResponse{Header: &pb.ResponseHeader{Revision: rev}, Hash: h}
+	ms.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ms *maintenanceServer) HashKV(ctx context.Context, r *pb.HashKVRequest) (*pb.HashKVResponse, error) {
+	h, rev, compactRev, err := ms.kg.KV().HashByRev(r.Revision)
+	if err != nil {
+		return nil, togRPCError(err)
+	}
+
+	resp := &pb.HashKVResponse{Header: &pb.ResponseHeader{Revision: rev}, Hash: h, CompactRevision: compactRev}
+	ms.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ms *maintenanceServer) Alarm(ctx context.Context, ar *pb.AlarmRequest) (*pb.AlarmResponse, error) {
+	return ms.a.Alarm(ctx, ar)
+}
+
+func (ms *maintenanceServer) Status(ctx context.Context, ar *pb.StatusRequest) (*pb.StatusResponse, error) {
+	resp := &pb.StatusResponse{
+		Header:    &pb.ResponseHeader{Revision: ms.hdr.rev()},
+		Version:   version.Version,
+		DbSize:    ms.bg.Backend().Size(),
+		Leader:    uint64(ms.rg.Leader()),
+		RaftIndex: ms.rg.Index(),
+		RaftTerm:  ms.rg.Term(),
+	}
+	ms.hdr.fill(resp.Header)
+	return resp, nil
+}
+
+func (ms *maintenanceServer) MoveLeader(ctx context.Context, tr *pb.MoveLeaderRequest) (*pb.MoveLeaderResponse, error) {
+	if ms.rg.ID() != ms.rg.Leader() {
+		return nil, rpctypes.ErrGRPCNotLeader
+	}
+
+	if err := ms.lt.MoveLeader(ctx, uint64(ms.rg.Leader()), tr.TargetID); err != nil {
+		return nil, togRPCError(err)
+	}
+	return &pb.MoveLeaderResponse{}, nil
+}
+
+type authMaintenanceServer struct {
+	*maintenanceServer
+	ag AuthGetter
+}
+
+func (ams *authMaintenanceServer) isAuthenticated(ctx context.Context) error {
+	authInfo, err := ams.ag.AuthInfoFromCtx(ctx)
+	if err != nil {
+		return err
+	}
+
+	return ams.ag.AuthStore().IsAdminPermitted(authInfo)
+}
+
+func (ams *authMaintenanceServer) Defragment(ctx context.Context, sr *pb.DefragmentRequest) (*pb.DefragmentResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+
+	return ams.maintenanceServer.Defragment(ctx, sr)
+}
+
+func (ams *authMaintenanceServer) Snapshot(sr *pb.SnapshotRequest, srv pb.Maintenance_SnapshotServer) error {
+	if err := ams.isAuthenticated(srv.Context()); err != nil {
+		return err
+	}
+
+	return ams.maintenanceServer.Snapshot(sr, srv)
+}
+
+func (ams *authMaintenanceServer) Hash(ctx context.Context, r *pb.HashRequest) (*pb.HashResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+
+	return ams.maintenanceServer.Hash(ctx, r)
+}
+
+func (ams *authMaintenanceServer) HashKV(ctx context.Context, r *pb.HashKVRequest) (*pb.HashKVResponse, error) {
+	if err := ams.isAuthenticated(ctx); err != nil {
+		return nil, err
+	}
+	return ams.maintenanceServer.HashKV(ctx, r)
+}
+
+func (ams *authMaintenanceServer) Status(ctx context.Context, ar *pb.StatusRequest) (*pb.StatusResponse, error) {
+	return ams.maintenanceServer.Status(ctx, ar)
+}
+
+func (ams *authMaintenanceServer) MoveLeader(ctx context.Context, tr *pb.MoveLeaderRequest) (*pb.MoveLeaderResponse, error) {
+	return ams.maintenanceServer.MoveLeader(ctx, tr)
+}