Adding upstream version 2.5.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

index/upsidedown/store/goleveldb/writer.go

@@ -0,0 +1,68 @@
+//  Copyright (c) 2014 Couchbase, Inc.
+//
+// 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 goleveldb
+
+import (
+	"fmt"
+
+	"github.com/blevesearch/goleveldb/leveldb"
+	store "github.com/blevesearch/upsidedown_store_api"
+)
+
+type Writer struct {
+	store *Store
+}
+
+func (w *Writer) NewBatch() store.KVBatch {
+	rv := Batch{
+		store: w.store,
+		merge: store.NewEmulatedMerge(w.store.mo),
+		batch: new(leveldb.Batch),
+	}
+	return &rv
+}
+
+func (w *Writer) NewBatchEx(options store.KVBatchOptions) ([]byte, store.KVBatch, error) {
+	return make([]byte, options.TotalBytes), w.NewBatch(), nil
+}
+
+func (w *Writer) ExecuteBatch(b store.KVBatch) error {
+	batch, ok := b.(*Batch)
+	if !ok {
+		return fmt.Errorf("wrong type of batch")
+	}
+
+	// first process merges
+	for k, mergeOps := range batch.merge.Merges {
+		kb := []byte(k)
+		existingVal, err := w.store.db.Get(kb, w.store.defaultReadOptions)
+		if err != nil && err != leveldb.ErrNotFound {
+			return err
+		}
+		mergedVal, fullMergeOk := w.store.mo.FullMerge(kb, existingVal, mergeOps)
+		if !fullMergeOk {
+			return fmt.Errorf("merge operator returned failure")
+		}
+		// add the final merge to this batch
+		batch.batch.Put(kb, mergedVal)
+	}
+
+	// now execute the batch
+	return w.store.db.Write(batch.batch, w.store.defaultWriteOptions)
+}
+
+func (w *Writer) Close() error {
+	return nil
+}