10a12b2a6f
Summary: Closes https://github.com/facebook/rocksdb/pull/2226 Differential Revision: D4967547 Pulled By: siying fbshipit-source-id: dd3b58ae1e7a106ab6bb6f37ab5c88575b125ab4
56 lines
2.3 KiB
C++
56 lines
2.3 KiB
C++
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
|
|
// This source code is licensed under the BSD-style license found in the
|
|
// LICENSE file in the root directory of this source tree. An additional grant
|
|
// of patent rights can be found in the PATENTS file in the same directory.
|
|
// This source code is also licensed under the GPLv2 license found in the
|
|
// COPYING file in the root directory of this source tree.
|
|
//
|
|
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file. See the AUTHORS file for names of contributors.
|
|
|
|
#pragma once
|
|
#include "rocksdb/iterator.h"
|
|
#include "rocksdb/env.h"
|
|
#include "table/iterator_wrapper.h"
|
|
|
|
namespace rocksdb {
|
|
|
|
struct ReadOptions;
|
|
class InternalKeyComparator;
|
|
class Arena;
|
|
|
|
struct TwoLevelIteratorState {
|
|
explicit TwoLevelIteratorState(bool _check_prefix_may_match)
|
|
: check_prefix_may_match(_check_prefix_may_match) {}
|
|
|
|
virtual ~TwoLevelIteratorState() {}
|
|
virtual InternalIterator* NewSecondaryIterator(const Slice& handle) = 0;
|
|
virtual bool PrefixMayMatch(const Slice& internal_key) = 0;
|
|
virtual bool KeyReachedUpperBound(const Slice& internal_key) = 0;
|
|
|
|
// If call PrefixMayMatch()
|
|
bool check_prefix_may_match;
|
|
};
|
|
|
|
|
|
// Return a new two level iterator. A two-level iterator contains an
|
|
// index iterator whose values point to a sequence of blocks where
|
|
// each block is itself a sequence of key,value pairs. The returned
|
|
// two-level iterator yields the concatenation of all key/value pairs
|
|
// in the sequence of blocks. Takes ownership of "index_iter" and
|
|
// will delete it when no longer needed.
|
|
//
|
|
// Uses a supplied function to convert an index_iter value into
|
|
// an iterator over the contents of the corresponding block.
|
|
// arena: If not null, the arena is used to allocate the Iterator.
|
|
// When destroying the iterator, the destructor will destroy
|
|
// all the states but those allocated in arena.
|
|
// need_free_iter_and_state: free `state` and `first_level_iter` if
|
|
// true. Otherwise, just call destructor.
|
|
extern InternalIterator* NewTwoLevelIterator(
|
|
TwoLevelIteratorState* state, InternalIterator* first_level_iter,
|
|
Arena* arena = nullptr, bool need_free_iter_and_state = true);
|
|
|
|
} // namespace rocksdb
|