diff options
Diffstat (limited to 'vendor/github.com/syndtr/goleveldb/leveldb/iterator')
4 files changed, 862 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/iterator/array_iter.go b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/array_iter.go new file mode 100644 index 000000000..a23ab05f7 --- /dev/null +++ b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/array_iter.go @@ -0,0 +1,184 @@ +// Copyright (c) 2014, 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/util" +) + +// BasicArray is the interface that wraps basic Len and Search method. +type BasicArray interface { + // Len returns length of the array. + Len() int + + // Search finds smallest index that point to a key that is greater + // than or equal to the given key. + Search(key []byte) int +} + +// Array is the interface that wraps BasicArray and basic Index method. +type Array interface { + BasicArray + + // Index returns key/value pair with index of i. + Index(i int) (key, value []byte) +} + +// Array is the interface that wraps BasicArray and basic Get method. +type ArrayIndexer interface { + BasicArray + + // Get returns a new data iterator with index of i. + Get(i int) Iterator +} + +type basicArrayIterator struct { + util.BasicReleaser + array BasicArray + pos int + err error +} + +func (i *basicArrayIterator) Valid() bool { + return i.pos >= 0 && i.pos < i.array.Len() && !i.Released() +} + +func (i *basicArrayIterator) First() bool { + if i.Released() { + i.err = ErrIterReleased + return false + } + + if i.array.Len() == 0 { + i.pos = -1 + return false + } + i.pos = 0 + return true +} + +func (i *basicArrayIterator) Last() bool { + if i.Released() { + i.err = ErrIterReleased + return false + } + + n := i.array.Len() + if n == 0 { + i.pos = 0 + return false + } + i.pos = n - 1 + return true +} + +func (i *basicArrayIterator) Seek(key []byte) bool { + if i.Released() { + i.err = ErrIterReleased + return false + } + + n := i.array.Len() + if n == 0 { + i.pos = 0 + return false + } + i.pos = i.array.Search(key) + if i.pos >= n { + return false + } + return true +} + +func (i *basicArrayIterator) Next() bool { + if i.Released() { + i.err = ErrIterReleased + return false + } + + i.pos++ + if n := i.array.Len(); i.pos >= n { + i.pos = n + return false + } + return true +} + +func (i *basicArrayIterator) Prev() bool { + if i.Released() { + i.err = ErrIterReleased + return false + } + + i.pos-- + if i.pos < 0 { + i.pos = -1 + return false + } + return true +} + +func (i *basicArrayIterator) Error() error { return i.err } + +type arrayIterator struct { + basicArrayIterator + array Array + pos int + key, value []byte +} + +func (i *arrayIterator) updateKV() { + if i.pos == i.basicArrayIterator.pos { + return + } + i.pos = i.basicArrayIterator.pos + if i.Valid() { + i.key, i.value = i.array.Index(i.pos) + } else { + i.key = nil + i.value = nil + } +} + +func (i *arrayIterator) Key() []byte { + i.updateKV() + return i.key +} + +func (i *arrayIterator) Value() []byte { + i.updateKV() + return i.value +} + +type arrayIteratorIndexer struct { + basicArrayIterator + array ArrayIndexer +} + +func (i *arrayIteratorIndexer) Get() Iterator { + if i.Valid() { + return i.array.Get(i.basicArrayIterator.pos) + } + return nil +} + +// NewArrayIterator returns an iterator from the given array. +func NewArrayIterator(array Array) Iterator { + return &arrayIterator{ + basicArrayIterator: basicArrayIterator{array: array, pos: -1}, + array: array, + pos: -1, + } +} + +// NewArrayIndexer returns an index iterator from the given array. +func NewArrayIndexer(array ArrayIndexer) IteratorIndexer { + return &arrayIteratorIndexer{ + basicArrayIterator: basicArrayIterator{array: array, pos: -1}, + array: array, + } +} 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} +} diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/iterator/iter.go b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/iter.go new file mode 100644 index 000000000..3b5553274 --- /dev/null +++ b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/iter.go @@ -0,0 +1,132 @@ +// 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 provides interface and implementation to traverse over +// contents of a database. +package iterator + +import ( + "errors" + + "github.com/syndtr/goleveldb/leveldb/util" +) + +var ( + ErrIterReleased = errors.New("leveldb/iterator: iterator released") +) + +// IteratorSeeker is the interface that wraps the 'seeks method'. +type IteratorSeeker interface { + // First moves the iterator to the first key/value pair. If the iterator + // only contains one key/value pair then First and Last would moves + // to the same key/value pair. + // It returns whether such pair exist. + First() bool + + // Last moves the iterator to the last key/value pair. If the iterator + // only contains one key/value pair then First and Last would moves + // to the same key/value pair. + // It returns whether such pair exist. + Last() bool + + // Seek moves the iterator to the first key/value pair whose key is greater + // than or equal to the given key. + // It returns whether such pair exist. + // + // It is safe to modify the contents of the argument after Seek returns. + Seek(key []byte) bool + + // Next moves the iterator to the next key/value pair. + // It returns whether the iterator is exhausted. + Next() bool + + // Prev moves the iterator to the previous key/value pair. + // It returns whether the iterator is exhausted. + Prev() bool +} + +// CommonIterator is the interface that wraps common iterator methods. +type CommonIterator interface { + IteratorSeeker + + // util.Releaser is the interface that wraps basic Release method. + // When called Release will releases any resources associated with the + // iterator. + util.Releaser + + // util.ReleaseSetter is the interface that wraps the basic SetReleaser + // method. + util.ReleaseSetter + + // TODO: Remove this when ready. + Valid() bool + + // Error returns any accumulated error. Exhausting all the key/value pairs + // is not considered to be an error. + Error() error +} + +// Iterator iterates over a DB's key/value pairs in key order. +// +// When encounter an error any 'seeks method' will return false and will +// yield no key/value pairs. The error can be queried by calling the Error +// method. Calling Release is still necessary. +// +// An iterator must be released after use, but it is not necessary to read +// an iterator until exhaustion. +// Also, an iterator is not necessarily safe for concurrent use, but it is +// safe to use multiple iterators concurrently, with each in a dedicated +// goroutine. +type Iterator interface { + CommonIterator + + // Key returns the key of the current key/value pair, or nil if done. + // The caller should not modify the contents of the returned slice, and + // its contents may change on the next call to any 'seeks method'. + Key() []byte + + // Value returns the key of the current key/value pair, or nil if done. + // The caller should not modify the contents of the returned slice, and + // its contents may change on the next call to any 'seeks method'. + Value() []byte +} + +// ErrorCallbackSetter is the interface that wraps basic SetErrorCallback +// method. +// +// ErrorCallbackSetter implemented by indexed and merged iterator. +type ErrorCallbackSetter interface { + // SetErrorCallback allows set an error callback of the corresponding + // iterator. Use nil to clear the callback. + SetErrorCallback(f func(err error)) +} + +type emptyIterator struct { + util.BasicReleaser + err error +} + +func (i *emptyIterator) rErr() { + if i.err == nil && i.Released() { + i.err = ErrIterReleased + } +} + +func (*emptyIterator) Valid() bool { return false } +func (i *emptyIterator) First() bool { i.rErr(); return false } +func (i *emptyIterator) Last() bool { i.rErr(); return false } +func (i *emptyIterator) Seek(key []byte) bool { i.rErr(); return false } +func (i *emptyIterator) Next() bool { i.rErr(); return false } +func (i *emptyIterator) Prev() bool { i.rErr(); return false } +func (*emptyIterator) Key() []byte { return nil } +func (*emptyIterator) Value() []byte { return nil } +func (i *emptyIterator) Error() error { return i.err } + +// NewEmptyIterator creates an empty iterator. The err parameter can be +// nil, but if not nil the given err will be returned by Error method. +func NewEmptyIterator(err error) Iterator { + return &emptyIterator{err: err} +} diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/iterator/merged_iter.go b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/merged_iter.go new file mode 100644 index 000000000..1a7e29df8 --- /dev/null +++ b/vendor/github.com/syndtr/goleveldb/leveldb/iterator/merged_iter.go @@ -0,0 +1,304 @@ +// 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/comparer" + "github.com/syndtr/goleveldb/leveldb/errors" + "github.com/syndtr/goleveldb/leveldb/util" +) + +type dir int + +const ( + dirReleased dir = iota - 1 + dirSOI + dirEOI + dirBackward + dirForward +) + +type mergedIterator struct { + cmp comparer.Comparer + iters []Iterator + strict bool + + keys [][]byte + index int + dir dir + err error + errf func(err error) + releaser util.Releaser +} + +func assertKey(key []byte) []byte { + if key == nil { + panic("leveldb/iterator: nil key") + } + return key +} + +func (i *mergedIterator) iterErr(iter Iterator) bool { + if err := iter.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 *mergedIterator) Valid() bool { + return i.err == nil && i.dir > dirEOI +} + +func (i *mergedIterator) First() bool { + if i.err != nil { + return false + } else if i.dir == dirReleased { + i.err = ErrIterReleased + return false + } + + for x, iter := range i.iters { + switch { + case iter.First(): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + } + i.dir = dirSOI + return i.next() +} + +func (i *mergedIterator) Last() bool { + if i.err != nil { + return false + } else if i.dir == dirReleased { + i.err = ErrIterReleased + return false + } + + for x, iter := range i.iters { + switch { + case iter.Last(): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + } + i.dir = dirEOI + return i.prev() +} + +func (i *mergedIterator) Seek(key []byte) bool { + if i.err != nil { + return false + } else if i.dir == dirReleased { + i.err = ErrIterReleased + return false + } + + for x, iter := range i.iters { + switch { + case iter.Seek(key): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + } + i.dir = dirSOI + return i.next() +} + +func (i *mergedIterator) next() bool { + var key []byte + if i.dir == dirForward { + key = i.keys[i.index] + } + for x, tkey := range i.keys { + if tkey != nil && (key == nil || i.cmp.Compare(tkey, key) < 0) { + key = tkey + i.index = x + } + } + if key == nil { + i.dir = dirEOI + return false + } + i.dir = dirForward + return true +} + +func (i *mergedIterator) Next() bool { + if i.dir == dirEOI || i.err != nil { + return false + } else if i.dir == dirReleased { + i.err = ErrIterReleased + return false + } + + switch i.dir { + case dirSOI: + return i.First() + case dirBackward: + key := append([]byte{}, i.keys[i.index]...) + if !i.Seek(key) { + return false + } + return i.Next() + } + + x := i.index + iter := i.iters[x] + switch { + case iter.Next(): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + return i.next() +} + +func (i *mergedIterator) prev() bool { + var key []byte + if i.dir == dirBackward { + key = i.keys[i.index] + } + for x, tkey := range i.keys { + if tkey != nil && (key == nil || i.cmp.Compare(tkey, key) > 0) { + key = tkey + i.index = x + } + } + if key == nil { + i.dir = dirSOI + return false + } + i.dir = dirBackward + return true +} + +func (i *mergedIterator) Prev() bool { + if i.dir == dirSOI || i.err != nil { + return false + } else if i.dir == dirReleased { + i.err = ErrIterReleased + return false + } + + switch i.dir { + case dirEOI: + return i.Last() + case dirForward: + key := append([]byte{}, i.keys[i.index]...) + for x, iter := range i.iters { + if x == i.index { + continue + } + seek := iter.Seek(key) + switch { + case seek && iter.Prev(), !seek && iter.Last(): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + } + } + + x := i.index + iter := i.iters[x] + switch { + case iter.Prev(): + i.keys[x] = assertKey(iter.Key()) + case i.iterErr(iter): + return false + default: + i.keys[x] = nil + } + return i.prev() +} + +func (i *mergedIterator) Key() []byte { + if i.err != nil || i.dir <= dirEOI { + return nil + } + return i.keys[i.index] +} + +func (i *mergedIterator) Value() []byte { + if i.err != nil || i.dir <= dirEOI { + return nil + } + return i.iters[i.index].Value() +} + +func (i *mergedIterator) Release() { + if i.dir != dirReleased { + i.dir = dirReleased + for _, iter := range i.iters { + iter.Release() + } + i.iters = nil + i.keys = nil + if i.releaser != nil { + i.releaser.Release() + i.releaser = nil + } + } +} + +func (i *mergedIterator) SetReleaser(releaser util.Releaser) { + if i.dir == dirReleased { + panic(util.ErrReleased) + } + if i.releaser != nil && releaser != nil { + panic(util.ErrHasReleaser) + } + i.releaser = releaser +} + +func (i *mergedIterator) Error() error { + return i.err +} + +func (i *mergedIterator) SetErrorCallback(f func(err error)) { + i.errf = f +} + +// NewMergedIterator returns an iterator that merges its input. Walking the +// resultant iterator will return all key/value pairs of all input iterators +// in strictly increasing key order, as defined by cmp. +// The input's key ranges may overlap, but there are assumed to be no duplicate +// keys: if iters[i] contains a key k then iters[j] will not contain that key k. +// None of the iters may be nil. +// +// If strict is true the any 'corruption errors' (i.e errors.IsCorrupted(err) == true) +// won't be ignored and will halt 'merged iterator', otherwise the iterator will +// continue to the next 'input iterator'. +func NewMergedIterator(iters []Iterator, cmp comparer.Comparer, strict bool) Iterator { + return &mergedIterator{ + iters: iters, + cmp: cmp, + strict: strict, + keys: make([][]byte, len(iters)), + } +} |