rocksdb/table/block_builder.h
Dhruba Borthakur a143ef9b38 Change namespace from leveldb to rocksdb
Summary:
Change namespace from leveldb to rocksdb. This allows a single
application to link in open-source leveldb code as well as
rocksdb code into the same process.

Test Plan: compile rocksdb

Reviewers: emayanke

Reviewed By: emayanke

CC: leveldb

Differential Revision: https://reviews.facebook.net/D13287
2013-10-04 11:59:26 -07:00

61 lines
1.9 KiB
C++

// 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.
#ifndef STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_
#define STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_
#include <vector>
#include <stdint.h>
#include "rocksdb/slice.h"
namespace rocksdb {
struct Options;
class BlockBuilder {
public:
explicit BlockBuilder(const Options* options);
// Reset the contents as if the BlockBuilder was just constructed.
void Reset();
// REQUIRES: Finish() has not been callled since the last call to Reset().
// REQUIRES: key is larger than any previously added key
void Add(const Slice& key, const Slice& value);
// Finish building the block and return a slice that refers to the
// block contents. The returned slice will remain valid for the
// lifetime of this builder or until Reset() is called.
Slice Finish();
// Returns an estimate of the current (uncompressed) size of the block
// we are building.
size_t CurrentSizeEstimate() const;
// Returns an estimated block size after appending key and value.
size_t EstimateSizeAfterKV(const Slice& key, const Slice& value) const;
// Return true iff no entries have been added since the last Reset()
bool empty() const {
return buffer_.empty();
}
private:
const Options* options_;
std::string buffer_; // Destination buffer
std::vector<uint32_t> restarts_; // Restart points
int counter_; // Number of entries emitted since restart
bool finished_; // Has Finish() been called?
std::string last_key_;
// No copying allowed
BlockBuilder(const BlockBuilder&);
void operator=(const BlockBuilder&);
};
} // namespace rocksdb
#endif // STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_