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rocksdb/include/rocksdb/convenience.h

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// 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 <string>
#include <unordered_map>
#include <vector>
#include "rocksdb/db.h"
#include "rocksdb/options.h"
#include "rocksdb/table.h"
namespace rocksdb {
#ifndef ROCKSDB_LITE
// The following set of functions provide a way to construct RocksDB Options
// from a string or a string-to-string map. Here're the general rule of
// setting option values from strings by type. Some RocksDB types are also
// supported in these APIs. Please refer to the comment of the function itself
// to find more information about how to config those RocksDB types.
//
// * Strings:
// Strings will be used as values directly without any truncating or
// trimming.
//
// * Booleans:
// - "true" or "1" => true
// - "false" or "0" => false.
// [Example]:
// - {"optimize_filters_for_hits", "1"} in GetColumnFamilyOptionsFromMap, or
// - "optimize_filters_for_hits=true" in GetColumnFamilyOptionsFromString.
//
// * Integers:
// Integers are converted directly from string, in addtion to the following
// units that we support:
// - 'k' or 'K' => 2^10
// - 'm' or 'M' => 2^20
// - 'g' or 'G' => 2^30
// - 't' or 'T' => 2^40 // only for unsigned int with sufficient bits.
// [Example]:
// - {"arena_block_size", "19G"} in GetColumnFamilyOptionsFromMap, or
// - "arena_block_size=19G" in GetColumnFamilyOptionsFromString.
//
// * Doubles / Floating Points:
// Doubles / Floating Points are converted directly from string. Note that
// currently we do not support units.
// [Example]:
// - {"hard_rate_limit", "2.1"} in GetColumnFamilyOptionsFromMap, or
// - "hard_rate_limit=2.1" in GetColumnFamilyOptionsFromString.
// * Array / Vectors:
// An array is specified by a list of values, where ':' is used as
// the delimiter to separate each value.
// [Example]:
// - {"compression_per_level", "kNoCompression:kSnappyCompression"}
// in GetColumnFamilyOptionsFromMap, or
// - "compression_per_level=kNoCompression:kSnappyCompression" in
// GetColumnFamilyOptionsFromMapString
// * Enums:
// The valid values of each enum are identical to the names of its constants.
// [Example]:
// - CompressionType: valid values are "kNoCompression",
// "kSnappyCompression", "kZlibCompression", "kBZip2Compression", ...
// - CompactionStyle: valid values are "kCompactionStyleLevel",
// "kCompactionStyleUniversal", "kCompactionStyleFIFO", and
// "kCompactionStyleNone".
//
// Take a default ColumnFamilyOptions "base_options" in addition to a
// map "opts_map" of option name to option value to construct the new
// ColumnFamilyOptions "new_options".
//
// Below are the instructions of how to config some non-primitive-typed
// options in ColumnFOptions:
//
// * table_factory:
// table_factory can be configured using our custom nested-option syntax.
//
// {option_a=value_a; option_b=value_b; option_c=value_c; ... }
//
// A nested option is enclosed by two curly braces, within which there are
// multiple option assignments. Each assignment is of the form
// "variable_name=value;".
//
// Currently we support the following types of TableFactory:
// - BlockBasedTableFactory:
// Use name "block_based_table_factory" to initialize table_factory with
// BlockBasedTableFactory. Its BlockBasedTableFactoryOptions can be
// configured using the nested-option syntax.
// [Example]:
// * {"block_based_table_factory", "{block_cache=1M;block_size=4k;}"}
// is equivalent to assigning table_factory with a BlockBasedTableFactory
// that has 1M LRU block-cache with block size equals to 4k:
// ColumnFamilyOptions cf_opt;
// BlockBasedTableOptions blk_opt;
// blk_opt.block_cache = NewLRUCache(1 * 1024 * 1024);
// blk_opt.block_size = 4 * 1024;
// cf_opt.table_factory.reset(NewBlockBasedTableFactory(blk_opt));
// - PlainTableFactory:
// Use name "plain_table_factory" to initialize table_factory with
// PlainTableFactory. Its PlainTableFactoryOptions can be configured using
// the nested-option syntax.
// [Example]:
// * {"plain_table_factory", "{user_key_len=66;bloom_bits_per_key=20;}"}
//
// * memtable_factory:
// Use "memtable" to config memtable_factory. Here are the supported
// memtable factories:
// - SkipList:
// Pass "skip_list:<lookahead>" to config memtable to use SkipList,
// or simply "skip_list" to use the default SkipList.
// [Example]:
// * {"memtable", "skip_list:5"} is equivalent to setting
// memtable to SkipListFactory(5).
// - PrefixHash:
// Pass "prfix_hash:<hash_bucket_count>" to config memtable
// to use PrefixHash, or simply "prefix_hash" to use the default
// PrefixHash.
// [Example]:
// * {"memtable", "prefix_hash:1000"} is equivalent to setting
// memtable to NewHashSkipListRepFactory(hash_bucket_count).
// - HashLinkedList:
// Pass "hash_linkedlist:<hash_bucket_count>" to config memtable
// to use HashLinkedList, or simply "hash_linkedlist" to use the default
// HashLinkedList.
// [Example]:
// * {"memtable", "hash_linkedlist:1000"} is equivalent to
// setting memtable to NewHashLinkListRepFactory(1000).
// - VectorRepFactory:
// Pass "vector:<count>" to config memtable to use VectorRepFactory,
// or simply "vector" to use the default Vector memtable.
// [Example]:
// * {"memtable", "vector:1024"} is equivalent to setting memtable
// to VectorRepFactory(1024).
// - HashCuckooRepFactory:
// Pass "cuckoo:<write_buffer_size>" to use HashCuckooRepFactory with the
// specified write buffer size, or simply "cuckoo" to use the default
// HashCuckooRepFactory.
// [Example]:
// * {"memtable", "cuckoo:1024"} is equivalent to setting memtable
// to NewHashCuckooRepFactory(1024).
//
// * compression_opts:
// Use "compression_opts" to config compression_opts. The value format
// is of the form "<window_bits>:<level>:<strategy>:<max_dict_bytes>".
// [Example]:
// * {"compression_opts", "4:5:6:7"} is equivalent to setting:
// ColumnFamilyOptions cf_opt;
// cf_opt.compression_opts.window_bits = 4;
// cf_opt.compression_opts.level = 5;
// cf_opt.compression_opts.strategy = 6;
// cf_opt.compression_opts.max_dict_bytes = 7;
//
// @param base_options the default options of the output "new_options".
// @param opts_map an option name to value map for specifying how "new_options"
// should be set.
// @param new_options the resulting options based on "base_options" with the
// change specified in "opts_map".
// @param input_strings_escaped when set to true, each escaped characters
// prefixed by '\' in the values of the opts_map will be further converted
// back to the raw string before assigning to the associated options.
// @return Status::OK() on success. Otherwise, a non-ok status indicating
// error will be returned, and "new_options" will be set to "base_options".
Status GetColumnFamilyOptionsFromMap(
const ColumnFamilyOptions& base_options,
const std::unordered_map<std::string, std::string>& opts_map,
ColumnFamilyOptions* new_options, bool input_strings_escaped = false);
// Take a default DBOptions "base_options" in addition to a
// map "opts_map" of option name to option value to construct the new
// DBOptions "new_options".
//
// Below are the instructions of how to config some non-primitive-typed
// options in DBOptions:
//
// * rate_limiter_bytes_per_sec:
// RateLimiter can be configured directly by specifying its bytes_per_sec.
// [Example]:
// - Passing {"rate_limiter_bytes_per_sec", "1024"} is equivalent to
// passing NewGenericRateLimiter(1024) to rate_limiter_bytes_per_sec.
//
// @param base_options the default options of the output "new_options".
// @param opts_map an option name to value map for specifying how "new_options"
// should be set.
// @param new_options the resulting options based on "base_options" with the
// change specified in "opts_map".
// @param input_strings_escaped when set to true, each escaped characters
// prefixed by '\' in the values of the opts_map will be further converted
// back to the raw string before assigning to the associated options.
// @return Status::OK() on success. Otherwise, a non-ok status indicating
// error will be returned, and "new_options" will be set to "base_options".
Status GetDBOptionsFromMap(
const DBOptions& base_options,
const std::unordered_map<std::string, std::string>& opts_map,
DBOptions* new_options, bool input_strings_escaped = false);
// Take a default BlockBasedTableOptions "table_options" in addition to a
// map "opts_map" of option name to option value to construct the new
// BlockBasedTableOptions "new_table_options".
//
// Below are the instructions of how to config some non-primitive-typed
// options in BlockBasedTableOptions:
//
// * filter_policy:
// We currently only support the following FilterPolicy in the convenience
// functions:
// - BloomFilter: use "bloomfilter:[bits_per_key]:[use_block_based_builder]"
// to specify BloomFilter. The above string is equivalent to calling
// NewBloomFilterPolicy(bits_per_key, use_block_based_builder).
// [Example]:
// - Pass {"filter_policy", "bloomfilter:4:true"} in
// GetBlockBasedTableOptionsFromMap to use a BloomFilter with 4-bits
// per key and use_block_based_builder enabled.
//
// * block_cache / block_cache_compressed:
// We currently only support LRU cache in the GetOptions API. The LRU
// cache can be set by directly specifying its size.
// [Example]:
// - Passing {"block_cache", "1M"} in GetBlockBasedTableOptionsFromMap is
// equivalent to setting block_cache using NewLRUCache(1024 * 1024).
//
// @param table_options the default options of the output "new_table_options".
// @param opts_map an option name to value map for specifying how
// "new_table_options" should be set.
// @param new_table_options the resulting options based on "table_options"
// with the change specified in "opts_map".
// @param input_strings_escaped when set to true, each escaped characters
// prefixed by '\' in the values of the opts_map will be further converted
// back to the raw string before assigning to the associated options.
// @return Status::OK() on success. Otherwise, a non-ok status indicating
// error will be returned, and "new_table_options" will be set to
// "table_options".
Status GetBlockBasedTableOptionsFromMap(
const BlockBasedTableOptions& table_options,
const std::unordered_map<std::string, std::string>& opts_map,
BlockBasedTableOptions* new_table_options,
bool input_strings_escaped = false);
// Take a default PlainTableOptions "table_options" in addition to a
// map "opts_map" of option name to option value to construct the new
// PlainTableOptions "new_table_options".
//
// @param table_options the default options of the output "new_table_options".
// @param opts_map an option name to value map for specifying how
// "new_table_options" should be set.
// @param new_table_options the resulting options based on "table_options"
// with the change specified in "opts_map".
// @param input_strings_escaped when set to true, each escaped characters
// prefixed by '\' in the values of the opts_map will be further converted
// back to the raw string before assigning to the associated options.
// @return Status::OK() on success. Otherwise, a non-ok status indicating
// error will be returned, and "new_table_options" will be set to
// "table_options".
Status GetPlainTableOptionsFromMap(
const PlainTableOptions& table_options,
const std::unordered_map<std::string, std::string>& opts_map,
PlainTableOptions* new_table_options,
bool input_strings_escaped = false);
// Take a string representation of option names and values, apply them into the
// base_options, and return the new options as a result. The string has the
// following format:
// "write_buffer_size=1024;max_write_buffer_number=2"
// Nested options config is also possible. For example, you can define
// BlockBasedTableOptions as part of the string for block-based table factory:
// "write_buffer_size=1024;block_based_table_factory={block_size=4k};"
// "max_write_buffer_num=2"
Status GetColumnFamilyOptionsFromString(
const ColumnFamilyOptions& base_options,
const std::string& opts_str,
ColumnFamilyOptions* new_options);
Status GetDBOptionsFromString(
const DBOptions& base_options,
const std::string& opts_str,
DBOptions* new_options);
Status GetStringFromDBOptions(std::string* opts_str,
const DBOptions& db_options,
const std::string& delimiter = "; ");
Status GetStringFromColumnFamilyOptions(std::string* opts_str,
const ColumnFamilyOptions& db_options,
const std::string& delimiter = "; ");
Status GetStringFromCompressionType(std::string* compression_str,
CompressionType compression_type);
Status GetBlockBasedTableOptionsFromString(
const BlockBasedTableOptions& table_options,
const std::string& opts_str,
BlockBasedTableOptions* new_table_options);
Status GetPlainTableOptionsFromString(
const PlainTableOptions& table_options,
const std::string& opts_str,
PlainTableOptions* new_table_options);
Status GetMemTableRepFactoryFromString(
const std::string& opts_str,
std::unique_ptr<MemTableRepFactory>* new_mem_factory);
Status GetOptionsFromString(const Options& base_options,
const std::string& opts_str, Options* new_options);
Status StringToMap(const std::string& opts_str,
std::unordered_map<std::string, std::string>* opts_map);
// Request stopping background work, if wait is true wait until it's done
void CancelAllBackgroundWork(DB* db, bool wait = false);
// Delete files which are entirely in the given range
// Could leave some keys in the range which are in files which are not
// entirely in the range.
// Snapshots before the delete might not see the data in the given range.
Status DeleteFilesInRange(DB* db, ColumnFamilyHandle* column_family,
const Slice* begin, const Slice* end);
#endif // ROCKSDB_LITE
} // namespace rocksdb