rocksdb/table/plain_table_builder.h
sdong edd47c5104 PlainTable to encode to avoid to rewrite prefix when it is the same as the previous key
Summary:
Add a encoding feature of PlainTable to encode PlainTable's keys to save some bytes for the same prefixes.
The data format is documented in table/plain_table_factory.h

Test Plan: Add unit test coverage in plain_table_db_test

Reviewers: yhchiang, igor, dhruba, ljin, haobo

Reviewed By: haobo

Subscribers: nkg-, leveldb

Differential Revision: https://reviews.facebook.net/D18735
2014-06-18 20:41:52 -07:00

85 lines
2.9 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.
#pragma once
#ifndef ROCKSDB_LITE
#include <stdint.h>
#include <vector>
#include "rocksdb/options.h"
#include "rocksdb/status.h"
#include "table/table_builder.h"
#include "table/plain_table_key_coding.h"
#include "rocksdb/table.h"
#include "rocksdb/table_properties.h"
namespace rocksdb {
class BlockBuilder;
class BlockHandle;
class WritableFile;
class TableBuilder;
class PlainTableBuilder: public TableBuilder {
public:
// Create a builder that will store the contents of the table it is
// building in *file. Does not close the file. It is up to the
// caller to close the file after calling Finish(). The output file
// will be part of level specified by 'level'. A value of -1 means
// that the caller does not know which level the output file will reside.
PlainTableBuilder(const Options& options, WritableFile* file,
uint32_t user_key_size, EncodingType encoding_type,
size_t index_sparseness);
// REQUIRES: Either Finish() or Abandon() has been called.
~PlainTableBuilder();
// Add key,value to the table being constructed.
// REQUIRES: key is after any previously added key according to comparator.
// REQUIRES: Finish(), Abandon() have not been called
void Add(const Slice& key, const Slice& value) override;
// Return non-ok iff some error has been detected.
Status status() const override;
// Finish building the table. Stops using the file passed to the
// constructor after this function returns.
// REQUIRES: Finish(), Abandon() have not been called
Status Finish() override;
// Indicate that the contents of this builder should be abandoned. Stops
// using the file passed to the constructor after this function returns.
// If the caller is not going to call Finish(), it must call Abandon()
// before destroying this builder.
// REQUIRES: Finish(), Abandon() have not been called
void Abandon() override;
// Number of calls to Add() so far.
uint64_t NumEntries() const override;
// Size of the file generated so far. If invoked after a successful
// Finish() call, returns the size of the final generated file.
uint64_t FileSize() const override;
private:
Options options_;
std::vector<std::unique_ptr<TablePropertiesCollector>>
table_properties_collectors_;
WritableFile* file_;
uint64_t offset_ = 0;
Status status_;
TableProperties properties_;
PlainTableKeyEncoder encoder_;
bool closed_ = false; // Either Finish() or Abandon() has been called.
// No copying allowed
PlainTableBuilder(const PlainTableBuilder&) = delete;
void operator=(const PlainTableBuilder&) = delete;
};
} // namespace rocksdb
#endif // ROCKSDB_LITE