Du kan inte välja fler än 25 ämnen
Ämnen måste starta med en bokstav eller siffra, kan innehålla bindestreck ('-') och vara max 35 tecken långa.
55 rader
1.7 KiB
55 rader
1.7 KiB
// 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 <stdint.h>
|
|
|
|
#include <vector>
|
|
|
|
#include "leveldb/slice.h"
|
|
|
|
namespace leveldb {
|
|
|
|
struct Options;
|
|
|
|
class BlockBuilder {
|
|
public:
|
|
explicit BlockBuilder(const Options* options);
|
|
|
|
BlockBuilder(const BlockBuilder&) = delete;
|
|
BlockBuilder& operator=(const BlockBuilder&) = delete;
|
|
|
|
// Reset the contents as if the BlockBuilder was just constructed.
|
|
void Reset();
|
|
|
|
// REQUIRES: Finish() has not been called 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;
|
|
|
|
// 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_;
|
|
};
|
|
|
|
} // namespace leveldb
|
|
|
|
#endif // STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_
|