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// 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 boltdb
import (
"bytes"
"github.com/boltdb/bolt"
)
type Iterator struct {
store *Store
tx *bolt.Tx
cursor *bolt.Cursor
prefix []byte
start []byte
end []byte
valid bool
key []byte
val []byte
}
func (i *Iterator) updateValid() {
i.valid = (i.key != nil)
if i.valid {
if i.prefix != nil {
i.valid = bytes.HasPrefix(i.key, i.prefix)
} else if i.end != nil {
i.valid = bytes.Compare(i.key, i.end) < 0
}
}
}
func (i *Iterator) Seek(k []byte) {
if i.start != nil && bytes.Compare(k, i.start) < 0 {
k = i.start
}
if i.prefix != nil && !bytes.HasPrefix(k, i.prefix) {
if bytes.Compare(k, i.prefix) < 0 {
k = i.prefix
} else {
i.valid = false
return
}
}
i.key, i.val = i.cursor.Seek(k)
i.updateValid()
}
func (i *Iterator) Next() {
i.key, i.val = i.cursor.Next()
i.updateValid()
}
func (i *Iterator) Current() ([]byte, []byte, bool) {
return i.key, i.val, i.valid
}
func (i *Iterator) Key() []byte {
return i.key
}
func (i *Iterator) Value() []byte {
return i.val
}
func (i *Iterator) Valid() bool {
return i.valid
}
func (i *Iterator) Close() error {
return nil
}
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