rename

writer/single.go

@@ -0,0 +1,84 @@
+// 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 writer
+
+import (
+	"sync"
+	"time"
+
+	"github.com/google/cayley/graph"
+)
+
+type Single struct {
+	nextID int64
+	ts     graph.TripleStore
+	mut    sync.Mutex
+}
+
+func NewSingleReplication(ts graph.TripleStore, opts graph.Options) (graph.TripleWriter, error) {
+	rep := &Single{nextID: ts.Horizon(), ts: ts}
+	if rep.nextID == -1 {
+		rep.nextID = 1
+	}
+	return rep, nil
+}
+
+func (s *Single) AcquireNextId() int64 {
+	s.mut.Lock()
+	defer s.mut.Unlock()
+	id := s.nextID
+	s.nextID += 1
+	return id
+}
+
+func (s *Single) AddTriple(t *graph.Triple) error {
+	trans := make([]*graph.Transaction, 1)
+	trans[0] = &graph.Transaction{
+		ID:        s.AcquireNextId(),
+		Triple:    t,
+		Action:    graph.Add,
+		Timestamp: time.Now(),
+	}
+	return s.ts.ApplyTransactions(trans)
+}
+
+func (s *Single) AddTripleSet(set []*graph.Triple) error {
+	trans := make([]*graph.Transaction, len(set))
+	for i, t := range set {
+		trans[i] = &graph.Transaction{
+			ID:        s.AcquireNextId(),
+			Triple:    t,
+			Action:    graph.Add,
+			Timestamp: time.Now(),
+		}
+	}
+	s.ts.ApplyTransactions(trans)
+	return nil
+}
+
+func (s *Single) RemoveTriple(t *graph.Triple) error {
+	trans := make([]*graph.Transaction, 1)
+	trans[0] = &graph.Transaction{
+		ID:        s.AcquireNextId(),
+		Triple:    t,
+		Action:    graph.Delete,
+		Timestamp: time.Now(),
+	}
+	return s.ts.ApplyTransactions(trans)
+}
+
+func init() {
+	graph.RegisterWriter("single", NewSingleReplication)
+}