1 // Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
2 // All rights reserved.
4 // Use of this source code is governed by a BSD-style license that can be
5 // found in the LICENSE file.
10 "github.com/syndtr/goleveldb/leveldb/errors"
11 "github.com/syndtr/goleveldb/leveldb/util"
14 // IteratorIndexer is the interface that wraps CommonIterator and basic Get
15 // method. IteratorIndexer provides index for indexed iterator.
16 type IteratorIndexer interface {
19 // Get returns a new data iterator for the current position, or nil if
24 type indexedIterator struct {
35 func (i *indexedIterator) setData() {
39 i.data = i.index.Get()
42 func (i *indexedIterator) clearData() {
49 func (i *indexedIterator) indexErr() {
50 if err := i.index.Error(); err != nil {
58 func (i *indexedIterator) dataErr() bool {
59 if err := i.data.Error(); err != nil {
63 if i.strict || !errors.IsCorrupted(err) {
71 func (i *indexedIterator) Valid() bool {
72 return i.data != nil && i.data.Valid()
75 func (i *indexedIterator) First() bool {
78 } else if i.Released() {
79 i.err = ErrIterReleased
92 func (i *indexedIterator) Last() bool {
95 } else if i.Released() {
96 i.err = ErrIterReleased
116 func (i *indexedIterator) Seek(key []byte) bool {
119 } else if i.Released() {
120 i.err = ErrIterReleased
124 if !i.index.Seek(key) {
130 if !i.data.Seek(key) {
140 func (i *indexedIterator) Next() bool {
143 } else if i.Released() {
144 i.err = ErrIterReleased
149 case i.data != nil && !i.data.Next():
166 func (i *indexedIterator) Prev() bool {
169 } else if i.Released() {
170 i.err = ErrIterReleased
175 case i.data != nil && !i.data.Prev():
198 func (i *indexedIterator) Key() []byte {
205 func (i *indexedIterator) Value() []byte {
209 return i.data.Value()
212 func (i *indexedIterator) Release() {
215 i.BasicReleaser.Release()
218 func (i *indexedIterator) Error() error {
222 if err := i.index.Error(); err != nil {
228 func (i *indexedIterator) SetErrorCallback(f func(err error)) {
232 // NewIndexedIterator returns an 'indexed iterator'. An index is iterator
233 // that returns another iterator, a 'data iterator'. A 'data iterator' is the
234 // iterator that contains actual key/value pairs.
236 // If strict is true the any 'corruption errors' (i.e errors.IsCorrupted(err) == true)
237 // won't be ignored and will halt 'indexed iterator', otherwise the iterator will
238 // continue to the next 'data iterator'. Corruption on 'index iterator' will not be
239 // ignored and will halt the iterator.
240 func NewIndexedIterator(index IteratorIndexer, strict bool) Iterator {
241 return &indexedIterator{index: index, strict: strict}