Adding upstream version 2.5.1.

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

index/upsidedown/store/moss/reader.go

@@ -0,0 +1,97 @@
+//  Copyright (c) 2016 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 moss
+
+import (
+	"github.com/couchbase/moss"
+
+	store "github.com/blevesearch/upsidedown_store_api"
+)
+
+type Reader struct {
+	store *Store
+	ss    moss.Snapshot
+}
+
+func (r *Reader) Get(k []byte) (v []byte, err error) {
+	v, err = r.ss.Get(k, moss.ReadOptions{})
+	if err != nil {
+		return nil, err
+	}
+	if v != nil {
+		return append(make([]byte, 0, len(v)), v...), nil
+	}
+	return nil, nil
+}
+
+func (r *Reader) MultiGet(keys [][]byte) ([][]byte, error) {
+	return store.MultiGet(r, keys)
+}
+
+func (r *Reader) PrefixIterator(k []byte) store.KVIterator {
+	kEnd := incrementBytes(k)
+
+	iter, err := r.ss.StartIterator(k, kEnd, moss.IteratorOptions{})
+	if err != nil {
+		return nil
+	}
+
+	rv := &Iterator{
+		store: r.store,
+		ss:    r.ss,
+		iter:  iter,
+		start: k,
+		end:   kEnd,
+	}
+
+	rv.current()
+
+	return rv
+}
+
+func (r *Reader) RangeIterator(start, end []byte) store.KVIterator {
+	iter, err := r.ss.StartIterator(start, end, moss.IteratorOptions{})
+	if err != nil {
+		return nil
+	}
+
+	rv := &Iterator{
+		store: r.store,
+		ss:    r.ss,
+		iter:  iter,
+		start: start,
+		end:   end,
+	}
+
+	rv.current()
+
+	return rv
+}
+
+func (r *Reader) Close() error {
+	return r.ss.Close()
+}
+
+func incrementBytes(in []byte) []byte {
+	rv := make([]byte, len(in))
+	copy(rv, in)
+	for i := len(rv) - 1; i >= 0; i-- {
+		rv[i] = rv[i] + 1
+		if rv[i] != 0 {
+			return rv // didn't overflow, so stop
+		}
+	}
+	return nil // overflowed
+}