rocksdb/table/block_based_table_builder.h
kailiu 74939a9e13 Make the block-based table's index pluggable
Summary:
This patch introduced a new table options that allows us to make
block-based table's index pluggable.

To support that new features:

* Code has been refacotred to be more flexible and supports this option well.
* More documentation is added for the existing obsecure functionalities.
* Big surgeon on DataBlockReader(), where the logic was really convoluted.
* Other small code cleanups.

The pluggablility will mostly affect development of internal modules
and won't change frequently, as a result I intentionally avoid
heavy-weight patterns (like factory) and try to make it simple.

Test Plan: make all check

Reviewers: haobo, sdong

Reviewed By: sdong

CC: leveldb

Differential Revision: https://reviews.facebook.net/D16395
2014-02-28 18:19:07 -08:00

92 lines
3.6 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 <stdint.h>
#include "rocksdb/flush_block_policy.h"
#include "rocksdb/options.h"
#include "rocksdb/status.h"
#include "table/table_builder.h"
namespace rocksdb {
class BlockBuilder;
class BlockHandle;
class WritableFile;
struct BlockBasedTableOptions;
class BlockBasedTableBuilder : 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().
BlockBasedTableBuilder(const Options& options,
const BlockBasedTableOptions& table_options,
const InternalKeyComparator& internal_comparator,
WritableFile* file, CompressionType compression_type);
// REQUIRES: Either Finish() or Abandon() has been called.
~BlockBasedTableBuilder();
// 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:
bool ok() const { return status().ok(); }
// Call block's Finish() method and then write the finalize block contents to
// file.
void WriteBlock(BlockBuilder* block, BlockHandle* handle);
// Directly write block content to the file.
void WriteBlock(const Slice& block_contents, BlockHandle* handle);
void WriteRawBlock(const Slice& data, CompressionType, BlockHandle* handle);
Status InsertBlockInCache(const Slice& block_contents,
const CompressionType type,
const BlockHandle* handle);
struct Rep;
class BlockBasedTablePropertiesCollector;
Rep* rep_;
// Advanced operation: flush any buffered key/value pairs to file.
// Can be used to ensure that two adjacent entries never live in
// the same data block. Most clients should not need to use this method.
// REQUIRES: Finish(), Abandon() have not been called
void Flush();
// No copying allowed
BlockBasedTableBuilder(const BlockBasedTableBuilder&) = delete;
void operator=(const BlockBasedTableBuilder&) = delete;
};
} // namespace rocksdb