rocksdb/table/block.h

62 lines
1.9 KiB
C++

// Copyright (c) 2013, 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.
//
// 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 <stddef.h>
#include <stdint.h>
#include "rocksdb/iterator.h"
#include "rocksdb/options.h"
namespace rocksdb {
struct BlockContents;
class Comparator;
class BlockHashIndex;
class Block {
public:
// Initialize the block with the specified contents.
explicit Block(const BlockContents& contents);
~Block();
size_t size() const { return size_; }
const char* data() const { return data_; }
bool cachable() const { return cachable_; }
uint32_t NumRestarts() const;
CompressionType compression_type() const { return compression_type_; }
// If hash index lookup is enabled and `use_hash_index` is true. This block
// will do hash lookup for the key prefix.
//
// NOTE: for the hash based lookup, if a key prefix doesn't match any key,
// the iterator will simply be set as "invalid", rather than returning
// the key that is just pass the target key.
Iterator* NewIterator(const Comparator* comparator);
void SetBlockHashIndex(BlockHashIndex* hash_index);
private:
const char* data_;
size_t size_;
uint32_t restart_offset_; // Offset in data_ of restart array
bool owned_; // Block owns data_[]
bool cachable_;
CompressionType compression_type_;
std::unique_ptr<BlockHashIndex> hash_index_;
// No copying allowed
Block(const Block&);
void operator=(const Block&);
class Iter;
};
} // namespace rocksdb