rocksdb/table/block_based_table_factory.h
Yueh-Hsuan Chiang e11f676e34 Add OptionsUtil::LoadOptionsFromFile() API
Summary:
This patch adds OptionsUtil::LoadOptionsFromFile() and
OptionsUtil::LoadLatestOptionsFromDB(), which allow developers
to construct DBOptions and ColumnFamilyOptions from a RocksDB
options file.  Note that most pointer-typed options such as
merge_operator will not be constructed.

With this API, developers no longer need to remember all the
options in order to reopen an existing rocksdb instance like
the following:

  DBOptions db_options;
  std::vector<std::string> cf_names;
  std::vector<ColumnFamilyOptions> cf_opts;

  // Load primitive-typed options from an existing DB
  OptionsUtil::LoadLatestOptionsFromDB(
      dbname, &db_options, &cf_names, &cf_opts);

  // Initialize necessary pointer-typed options
  cf_opts[0].merge_operator.reset(new MyMergeOperator());
  ...

  // Construct the vector of ColumnFamilyDescriptor
  std::vector<ColumnFamilyDescriptor> cf_descs;
  for (size_t i = 0; i < cf_opts.size(); ++i) {
    cf_descs.emplace_back(cf_names[i], cf_opts[i]);
  }

  // Open the DB
  DB* db = nullptr;
  std::vector<ColumnFamilyHandle*> cf_handles;
  auto s = DB::Open(db_options, dbname, cf_descs,
                    &handles, &db);

Test Plan:
Augment existing tests in column_family_test
options_test
db_test

Reviewers: igor, IslamAbdelRahman, sdong, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49095
2015-11-12 06:52:43 -08:00

73 lines
2.5 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 <memory>
#include <string>
#include "rocksdb/flush_block_policy.h"
#include "rocksdb/table.h"
#include "db/dbformat.h"
namespace rocksdb {
struct EnvOptions;
using std::unique_ptr;
class BlockBasedTableBuilder;
class BlockBasedTableFactory : public TableFactory {
public:
explicit BlockBasedTableFactory(
const BlockBasedTableOptions& table_options = BlockBasedTableOptions());
~BlockBasedTableFactory() {}
const char* Name() const override { return "BlockBasedTable"; }
Status NewTableReader(const TableReaderOptions& table_reader_options,
unique_ptr<RandomAccessFileReader>&& file,
uint64_t file_size,
unique_ptr<TableReader>* table_reader) const override;
// This is a variant of virtual member function NewTableReader function with
// added capability to disable pre-fetching of blocks on BlockBasedTable::Open
Status NewTableReader(const TableReaderOptions& table_reader_options,
unique_ptr<RandomAccessFileReader>&& file,
uint64_t file_size,
unique_ptr<TableReader>* table_reader,
bool prefetch_index_and_filter) const;
TableBuilder* NewTableBuilder(
const TableBuilderOptions& table_builder_options,
uint32_t column_family_id, WritableFileWriter* file) const override;
// Sanitizes the specified DB Options.
Status SanitizeOptions(const DBOptions& db_opts,
const ColumnFamilyOptions& cf_opts) const override;
std::string GetPrintableTableOptions() const override;
const BlockBasedTableOptions& GetTableOptions() const;
void* GetOptions() override { return &table_options_; }
private:
BlockBasedTableOptions table_options_;
};
extern const std::string kHashIndexPrefixesBlock;
extern const std::string kHashIndexPrefixesMetadataBlock;
extern const std::string kPropTrue;
extern const std::string kPropFalse;
} // namespace rocksdb