| // Copyright (c) 2011-present, Facebook, Inc. All rights reserved. |
| // This source code is licensed under both the GPLv2 (found in the |
| // COPYING file in the root directory) and Apache 2.0 License |
| // (found in the LICENSE.Apache file in the root directory). |
| |
| // This file contains utility functions for RocksDB Options. |
| #pragma once |
| |
| #ifndef ROCKSDB_LITE |
| |
| #include <string> |
| #include <vector> |
| |
| #include "rocksdb/db.h" |
| #include "rocksdb/env.h" |
| #include "rocksdb/options.h" |
| #include "rocksdb/status.h" |
| |
| namespace rocksdb { |
| // Constructs the DBOptions and ColumnFamilyDescriptors by loading the |
| // latest RocksDB options file stored in the specified rocksdb database. |
| // |
| // Note that the all the pointer options (except table_factory, which will |
| // be described in more details below) will be initialized with the default |
| // values. Developers can further initialize them after this function call. |
| // Below is an example list of pointer options which will be initialized |
| // |
| // * env |
| // * memtable_factory |
| // * compaction_filter_factory |
| // * prefix_extractor |
| // * comparator |
| // * merge_operator |
| // * compaction_filter |
| // |
| // For table_factory, this function further supports deserializing |
| // BlockBasedTableFactory and its BlockBasedTableOptions except the |
| // pointer options of BlockBasedTableOptions (flush_block_policy_factory, |
| // block_cache, and block_cache_compressed), which will be initialized with |
| // default values. Developers can further specify these three options by |
| // casting the return value of TableFactoroy::GetOptions() to |
| // BlockBasedTableOptions and making necessary changes. |
| // |
| // ignore_unknown_options can be set to true if you want to ignore options |
| // that are from a newer version of the db, esentially for forward |
| // compatibility. |
| // |
| // examples/options_file_example.cc demonstrates how to use this function |
| // to open a RocksDB instance. |
| // |
| // @return the function returns an OK status when it went successfully. If |
| // the specified "dbpath" does not contain any option file, then a |
| // Status::NotFound will be returned. A return value other than |
| // Status::OK or Status::NotFound indicates there're some error related |
| // to the options file itself. |
| // |
| // @see LoadOptionsFromFile |
| Status LoadLatestOptions(const std::string& dbpath, Env* env, |
| DBOptions* db_options, |
| std::vector<ColumnFamilyDescriptor>* cf_descs, |
| bool ignore_unknown_options = false); |
| |
| // Similar to LoadLatestOptions, this function constructs the DBOptions |
| // and ColumnFamilyDescriptors based on the specified RocksDB Options file. |
| // |
| // @see LoadLatestOptions |
| Status LoadOptionsFromFile(const std::string& options_file_name, Env* env, |
| DBOptions* db_options, |
| std::vector<ColumnFamilyDescriptor>* cf_descs, |
| bool ignore_unknown_options = false); |
| |
| // Returns the latest options file name under the specified db path. |
| Status GetLatestOptionsFileName(const std::string& dbpath, Env* env, |
| std::string* options_file_name); |
| |
| // Returns Status::OK if the input DBOptions and ColumnFamilyDescriptors |
| // are compatible with the latest options stored in the specified DB path. |
| // |
| // If the return status is non-ok, it means the specified RocksDB instance |
| // might not be correctly opened with the input set of options. Currently, |
| // changing one of the following options will fail the compatibility check: |
| // |
| // * comparator |
| // * prefix_extractor |
| // * table_factory |
| // * merge_operator |
| Status CheckOptionsCompatibility( |
| const std::string& dbpath, Env* env, const DBOptions& db_options, |
| const std::vector<ColumnFamilyDescriptor>& cf_descs, |
| bool ignore_unknown_options = false); |
| |
| } // namespace rocksdb |
| #endif // !ROCKSDB_LITE |
