fork of https://github.com/oxigraph/rocksdb and https://github.com/facebook/rocksdb for nextgraph and oxigraph
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
3.3 KiB
86 lines
3.3 KiB
// 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).
|
|
|
|
#pragma once
|
|
|
|
#include <stdint.h>
|
|
#include <climits>
|
|
#include <vector>
|
|
|
|
namespace ROCKSDB_NAMESPACE {
|
|
|
|
//
|
|
// Algorithm used to make a compaction request stop picking new files
|
|
// into a single compaction run
|
|
//
|
|
enum CompactionStopStyle {
|
|
kCompactionStopStyleSimilarSize, // pick files of similar size
|
|
kCompactionStopStyleTotalSize // total size of picked files > next file
|
|
};
|
|
|
|
class CompactionOptionsUniversal {
|
|
public:
|
|
// Percentage flexibility while comparing file size. If the candidate file(s)
|
|
// size is 1% smaller than the next file's size, then include next file into
|
|
// this candidate set. // Default: 1
|
|
unsigned int size_ratio;
|
|
|
|
// The minimum number of files in a single compaction run. Default: 2
|
|
unsigned int min_merge_width;
|
|
|
|
// The maximum number of files in a single compaction run. Default: UINT_MAX
|
|
unsigned int max_merge_width;
|
|
|
|
// The size amplification is defined as the amount (in percentage) of
|
|
// additional storage needed to store a single byte of data in the database.
|
|
// For example, a size amplification of 2% means that a database that
|
|
// contains 100 bytes of user-data may occupy upto 102 bytes of
|
|
// physical storage. By this definition, a fully compacted database has
|
|
// a size amplification of 0%. Rocksdb uses the following heuristic
|
|
// to calculate size amplification: it assumes that all files excluding
|
|
// the earliest file contribute to the size amplification.
|
|
// Default: 200, which means that a 100 byte database could require upto
|
|
// 300 bytes of storage.
|
|
unsigned int max_size_amplification_percent;
|
|
|
|
// If this option is set to be -1 (the default value), all the output files
|
|
// will follow compression type specified.
|
|
//
|
|
// If this option is not negative, we will try to make sure compressed
|
|
// size is just above this value. In normal cases, at least this percentage
|
|
// of data will be compressed.
|
|
// When we are compacting to a new file, here is the criteria whether
|
|
// it needs to be compressed: assuming here are the list of files sorted
|
|
// by generation time:
|
|
// A1...An B1...Bm C1...Ct
|
|
// where A1 is the newest and Ct is the oldest, and we are going to compact
|
|
// B1...Bm, we calculate the total size of all the files as total_size, as
|
|
// well as the total size of C1...Ct as total_C, the compaction output file
|
|
// will be compressed iff
|
|
// total_C / total_size < this percentage
|
|
// Default: -1
|
|
int compression_size_percent;
|
|
|
|
// The algorithm used to stop picking files into a single compaction run
|
|
// Default: kCompactionStopStyleTotalSize
|
|
CompactionStopStyle stop_style;
|
|
|
|
// Option to optimize the universal multi level compaction by enabling
|
|
// trivial move for non overlapping files.
|
|
// Default: false
|
|
bool allow_trivial_move;
|
|
|
|
// Default set of parameters
|
|
CompactionOptionsUniversal()
|
|
: size_ratio(1),
|
|
min_merge_width(2),
|
|
max_merge_width(UINT_MAX),
|
|
max_size_amplification_percent(200),
|
|
compression_size_percent(-1),
|
|
stop_style(kCompactionStopStyleTotalSize),
|
|
allow_trivial_move(false) {}
|
|
};
|
|
|
|
} // namespace ROCKSDB_NAMESPACE
|
|
|