[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go
new file mode 100644
index 0000000..cf8ac43
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/api/v3compactor/revision.go
@@ -0,0 +1,143 @@
+// Copyright 2017 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 v3compactor
+
+import (
+	"context"
+	"sync"
+	"time"
+
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/mvcc"
+
+	"github.com/jonboulle/clockwork"
+	"go.uber.org/zap"
+)
+
+// Revision compacts the log by purging revisions older than
+// the configured reivison number. Compaction happens every 5 minutes.
+type Revision struct {
+	lg *zap.Logger
+
+	clock     clockwork.Clock
+	retention int64
+
+	rg RevGetter
+	c  Compactable
+
+	ctx    context.Context
+	cancel context.CancelFunc
+
+	mu     sync.Mutex
+	paused bool
+}
+
+// newRevision creates a new instance of Revisonal compactor that purges
+// the log older than retention revisions from the current revision.
+func newRevision(lg *zap.Logger, clock clockwork.Clock, retention int64, rg RevGetter, c Compactable) *Revision {
+	rc := &Revision{
+		lg:        lg,
+		clock:     clock,
+		retention: retention,
+		rg:        rg,
+		c:         c,
+	}
+	rc.ctx, rc.cancel = context.WithCancel(context.Background())
+	return rc
+}
+
+const revInterval = 5 * time.Minute
+
+// Run runs revision-based compactor.
+func (rc *Revision) Run() {
+	prev := int64(0)
+	go func() {
+		for {
+			select {
+			case <-rc.ctx.Done():
+				return
+			case <-rc.clock.After(revInterval):
+				rc.mu.Lock()
+				p := rc.paused
+				rc.mu.Unlock()
+				if p {
+					continue
+				}
+			}
+
+			rev := rc.rg.Rev() - rc.retention
+			if rev <= 0 || rev == prev {
+				continue
+			}
+
+			now := time.Now()
+			if rc.lg != nil {
+				rc.lg.Info(
+					"starting auto revision compaction",
+					zap.Int64("revision", rev),
+					zap.Int64("revision-compaction-retention", rc.retention),
+				)
+			} else {
+				plog.Noticef("Starting auto-compaction at revision %d (retention: %d revisions)", rev, rc.retention)
+			}
+			_, err := rc.c.Compact(rc.ctx, &pb.CompactionRequest{Revision: rev})
+			if err == nil || err == mvcc.ErrCompacted {
+				prev = rev
+				if rc.lg != nil {
+					rc.lg.Info(
+						"completed auto revision compaction",
+						zap.Int64("revision", rev),
+						zap.Int64("revision-compaction-retention", rc.retention),
+						zap.Duration("took", time.Since(now)),
+					)
+				} else {
+					plog.Noticef("Finished auto-compaction at revision %d", rev)
+				}
+			} else {
+				if rc.lg != nil {
+					rc.lg.Warn(
+						"failed auto revision compaction",
+						zap.Int64("revision", rev),
+						zap.Int64("revision-compaction-retention", rc.retention),
+						zap.Duration("retry-interval", revInterval),
+						zap.Error(err),
+					)
+				} else {
+					plog.Noticef("Failed auto-compaction at revision %d (%v)", rev, err)
+					plog.Noticef("Retry after %v", revInterval)
+				}
+			}
+		}
+	}()
+}
+
+// Stop stops revision-based compactor.
+func (rc *Revision) Stop() {
+	rc.cancel()
+}
+
+// Pause pauses revision-based compactor.
+func (rc *Revision) Pause() {
+	rc.mu.Lock()
+	rc.paused = true
+	rc.mu.Unlock()
+}
+
+// Resume resumes revision-based compactor.
+func (rc *Revision) Resume() {
+	rc.mu.Lock()
+	rc.paused = false
+	rc.mu.Unlock()
+}