add replication registry and local replication

replication/local.go

@@ -0,0 +1,52 @@
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// 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 local
+
+import (
+	"github.com/google/cayley/graph"
+	"sync"
+)
+
+type LocalReplication struct {
+	lastId int64
+	ts     graph.TripleStore
+	mut    sync.Mutex
+}
+
+func NewLocalReplication(ts graph.TripleStore, opts graph.Options) (*LocalReplication, error) {
+	rep := &LocalReplication{lastId: ts.Horizon(), ts: ts}
+	ts.SetReplication(rep)
+	return rep, nil
+}
+
+func (l *LocalReplication) AcquireNextIds(size int64) (start int64, end int64) {
+	l.mut.Lock()
+	defer l.mut.Unlock()
+	start = l.lastId + 1
+	end = l.lastId + size
+	l.lastId += size
+	return
+}
+
+func (l *LocalReplication) GetLastId() int64 {
+	return l.lastId
+}
+
+func (l *LocalReplication) Replicate([]*graph.Transaction)       {}
+func (l *LocalReplication) RequestTransactionRange(int64, int64) {}
+
+func init() {
+	graph.RegisterReplication("local", NewLocalReplication)
+}