rocksdb/table/meta_blocks.h
2016-02-09 15:12:00 -08:00

128 lines
4.8 KiB
C++

// Copyright (c) 2011-present, 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
#include <map>
#include <memory>
#include <string>
#include <vector>
#include "db/builder.h"
#include "db/table_properties_collector.h"
#include "util/kv_map.h"
#include "rocksdb/comparator.h"
#include "rocksdb/options.h"
#include "rocksdb/slice.h"
#include "table/block_builder.h"
#include "table/format.h"
namespace rocksdb {
class BlockBuilder;
class BlockHandle;
class Env;
class Footer;
class Logger;
class RandomAccessFile;
struct TableProperties;
class InternalIterator;
class MetaIndexBuilder {
public:
MetaIndexBuilder(const MetaIndexBuilder&) = delete;
MetaIndexBuilder& operator=(const MetaIndexBuilder&) = delete;
MetaIndexBuilder();
void Add(const std::string& key, const BlockHandle& handle);
// Write all the added key/value pairs to the block and return the contents
// of the block.
Slice Finish();
private:
// store the sorted key/handle of the metablocks.
stl_wrappers::KVMap meta_block_handles_;
std::unique_ptr<BlockBuilder> meta_index_block_;
};
class PropertyBlockBuilder {
public:
PropertyBlockBuilder(const PropertyBlockBuilder&) = delete;
PropertyBlockBuilder& operator=(const PropertyBlockBuilder&) = delete;
PropertyBlockBuilder();
void AddTableProperty(const TableProperties& props);
void Add(const std::string& key, uint64_t value);
void Add(const std::string& key, const std::string& value);
void Add(const UserCollectedProperties& user_collected_properties);
// Write all the added entries to the block and return the block contents
Slice Finish();
private:
std::unique_ptr<BlockBuilder> properties_block_;
stl_wrappers::KVMap props_;
};
// Were we encounter any error occurs during user-defined statistics collection,
// we'll write the warning message to info log.
void LogPropertiesCollectionError(
Logger* info_log, const std::string& method, const std::string& name);
// Utility functions help table builder to trigger batch events for user
// defined property collectors.
// Return value indicates if there is any error occurred; if error occurred,
// the warning message will be logged.
// NotifyCollectTableCollectorsOnAdd() triggers the `Add` event for all
// property collectors.
bool NotifyCollectTableCollectorsOnAdd(
const Slice& key, const Slice& value, uint64_t file_size,
const std::vector<std::unique_ptr<IntTblPropCollector>>& collectors,
Logger* info_log);
// NotifyCollectTableCollectorsOnAdd() triggers the `Finish` event for all
// property collectors. The collected properties will be added to `builder`.
bool NotifyCollectTableCollectorsOnFinish(
const std::vector<std::unique_ptr<IntTblPropCollector>>& collectors,
Logger* info_log, PropertyBlockBuilder* builder);
// Read the properties from the table.
// @returns a status to indicate if the operation succeeded. On success,
// *table_properties will point to a heap-allocated TableProperties
// object, otherwise value of `table_properties` will not be modified.
Status ReadProperties(const Slice& handle_value, RandomAccessFileReader* file,
const Footer& footer, Env* env, Logger* logger,
TableProperties** table_properties);
// Directly read the properties from the properties block of a plain table.
// @returns a status to indicate if the operation succeeded. On success,
// *table_properties will point to a heap-allocated TableProperties
// object, otherwise value of `table_properties` will not be modified.
Status ReadTableProperties(RandomAccessFileReader* file, uint64_t file_size,
uint64_t table_magic_number, Env* env,
Logger* info_log, TableProperties** properties);
// Find the meta block from the meta index block.
Status FindMetaBlock(InternalIterator* meta_index_iter,
const std::string& meta_block_name,
BlockHandle* block_handle);
// Find the meta block
Status FindMetaBlock(RandomAccessFileReader* file, uint64_t file_size,
uint64_t table_magic_number, Env* env,
const std::string& meta_block_name,
BlockHandle* block_handle);
// Read the specified meta block with name meta_block_name
// from `file` and initialize `contents` with contents of this block.
// Return Status::OK in case of success.
Status ReadMetaBlock(RandomAccessFileReader* file, uint64_t file_size,
uint64_t table_magic_number, Env* env,
const std::string& meta_block_name,
BlockContents* contents);
} // namespace rocksdb