diff options
Diffstat (limited to 'vendor/github.com/syndtr/goleveldb/leveldb/iterator/indexed_iter.go')
-rw-r--r-- | vendor/github.com/syndtr/goleveldb/leveldb/iterator/indexed_iter.go | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/iterator/indexed_iter.go b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/indexed_iter.go new file mode 100644 index 000000000..939adbb93 --- /dev/null +++ b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/indexed_iter.go @@ -0,0 +1,242 @@ +// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com> +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +package iterator + +import ( + "github.com/syndtr/goleveldb/leveldb/errors" + "github.com/syndtr/goleveldb/leveldb/util" +) + +// IteratorIndexer is the interface that wraps CommonIterator and basic Get +// method. IteratorIndexer provides index for indexed iterator. +type IteratorIndexer interface { + CommonIterator + + // Get returns a new data iterator for the current position, or nil if + // done. + Get() Iterator +} + +type indexedIterator struct { + util.BasicReleaser + index IteratorIndexer + strict bool + + data Iterator + err error + errf func(err error) + closed bool +} + +func (i *indexedIterator) setData() { + if i.data != nil { + i.data.Release() + } + i.data = i.index.Get() +} + +func (i *indexedIterator) clearData() { + if i.data != nil { + i.data.Release() + } + i.data = nil +} + +func (i *indexedIterator) indexErr() { + if err := i.index.Error(); err != nil { + if i.errf != nil { + i.errf(err) + } + i.err = err + } +} + +func (i *indexedIterator) dataErr() bool { + if err := i.data.Error(); err != nil { + if i.errf != nil { + i.errf(err) + } + if i.strict || !errors.IsCorrupted(err) { + i.err = err + return true + } + } + return false +} + +func (i *indexedIterator) Valid() bool { + return i.data != nil && i.data.Valid() +} + +func (i *indexedIterator) First() bool { + if i.err != nil { + return false + } else if i.Released() { + i.err = ErrIterReleased + return false + } + + if !i.index.First() { + i.indexErr() + i.clearData() + return false + } + i.setData() + return i.Next() +} + +func (i *indexedIterator) Last() bool { + if i.err != nil { + return false + } else if i.Released() { + i.err = ErrIterReleased + return false + } + + if !i.index.Last() { + i.indexErr() + i.clearData() + return false + } + i.setData() + if !i.data.Last() { + if i.dataErr() { + return false + } + i.clearData() + return i.Prev() + } + return true +} + +func (i *indexedIterator) Seek(key []byte) bool { + if i.err != nil { + return false + } else if i.Released() { + i.err = ErrIterReleased + return false + } + + if !i.index.Seek(key) { + i.indexErr() + i.clearData() + return false + } + i.setData() + if !i.data.Seek(key) { + if i.dataErr() { + return false + } + i.clearData() + return i.Next() + } + return true +} + +func (i *indexedIterator) Next() bool { + if i.err != nil { + return false + } else if i.Released() { + i.err = ErrIterReleased + return false + } + + switch { + case i.data != nil && !i.data.Next(): + if i.dataErr() { + return false + } + i.clearData() + fallthrough + case i.data == nil: + if !i.index.Next() { + i.indexErr() + return false + } + i.setData() + return i.Next() + } + return true +} + +func (i *indexedIterator) Prev() bool { + if i.err != nil { + return false + } else if i.Released() { + i.err = ErrIterReleased + return false + } + + switch { + case i.data != nil && !i.data.Prev(): + if i.dataErr() { + return false + } + i.clearData() + fallthrough + case i.data == nil: + if !i.index.Prev() { + i.indexErr() + return false + } + i.setData() + if !i.data.Last() { + if i.dataErr() { + return false + } + i.clearData() + return i.Prev() + } + } + return true +} + +func (i *indexedIterator) Key() []byte { + if i.data == nil { + return nil + } + return i.data.Key() +} + +func (i *indexedIterator) Value() []byte { + if i.data == nil { + return nil + } + return i.data.Value() +} + +func (i *indexedIterator) Release() { + i.clearData() + i.index.Release() + i.BasicReleaser.Release() +} + +func (i *indexedIterator) Error() error { + if i.err != nil { + return i.err + } + if err := i.index.Error(); err != nil { + return err + } + return nil +} + +func (i *indexedIterator) SetErrorCallback(f func(err error)) { + i.errf = f +} + +// NewIndexedIterator returns an 'indexed iterator'. An index is iterator +// that returns another iterator, a 'data iterator'. A 'data iterator' is the +// iterator that contains actual key/value pairs. +// +// If strict is true the any 'corruption errors' (i.e errors.IsCorrupted(err) == true) +// won't be ignored and will halt 'indexed iterator', otherwise the iterator will +// continue to the next 'data iterator'. Corruption on 'index iterator' will not be +// ignored and will halt the iterator. +func NewIndexedIterator(index IteratorIndexer, strict bool) Iterator { + return &indexedIterator{index: index, strict: strict} +} |