mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-12-25 03:40:10 +01:00
158 lines
6.9 KiB
Go
158 lines
6.9 KiB
Go
// Copyright 2019+ Klaus Post. All rights reserved.
|
|
// License information can be found in the LICENSE file.
|
|
// Based on work by Yann Collet, released under BSD License.
|
|
|
|
package zstd
|
|
|
|
/*
|
|
// encParams are not really used, just here for reference.
|
|
type encParams struct {
|
|
// largest match distance : larger == more compression, more memory needed during decompression
|
|
windowLog uint8
|
|
|
|
// fully searched segment : larger == more compression, slower, more memory (useless for fast)
|
|
chainLog uint8
|
|
|
|
// dispatch table : larger == faster, more memory
|
|
hashLog uint8
|
|
|
|
// < nb of searches : larger == more compression, slower
|
|
searchLog uint8
|
|
|
|
// < match length searched : larger == faster decompression, sometimes less compression
|
|
minMatch uint8
|
|
|
|
// acceptable match size for optimal parser (only) : larger == more compression, slower
|
|
targetLength uint32
|
|
|
|
// see ZSTD_strategy definition above
|
|
strategy strategy
|
|
}
|
|
|
|
// strategy defines the algorithm to use when generating sequences.
|
|
type strategy uint8
|
|
|
|
const (
|
|
// Compression strategies, listed from fastest to strongest
|
|
strategyFast strategy = iota + 1
|
|
strategyDfast
|
|
strategyGreedy
|
|
strategyLazy
|
|
strategyLazy2
|
|
strategyBtlazy2
|
|
strategyBtopt
|
|
strategyBtultra
|
|
strategyBtultra2
|
|
// note : new strategies _might_ be added in the future.
|
|
// Only the order (from fast to strong) is guaranteed
|
|
|
|
)
|
|
|
|
var defEncParams = [4][]encParams{
|
|
{ // "default" - for any srcSize > 256 KB
|
|
// W, C, H, S, L, TL, strat
|
|
{19, 12, 13, 1, 6, 1, strategyFast}, // base for negative levels
|
|
{19, 13, 14, 1, 7, 0, strategyFast}, // level 1
|
|
{20, 15, 16, 1, 6, 0, strategyFast}, // level 2
|
|
{21, 16, 17, 1, 5, 1, strategyDfast}, // level 3
|
|
{21, 18, 18, 1, 5, 1, strategyDfast}, // level 4
|
|
{21, 18, 19, 2, 5, 2, strategyGreedy}, // level 5
|
|
{21, 19, 19, 3, 5, 4, strategyGreedy}, // level 6
|
|
{21, 19, 19, 3, 5, 8, strategyLazy}, // level 7
|
|
{21, 19, 19, 3, 5, 16, strategyLazy2}, // level 8
|
|
{21, 19, 20, 4, 5, 16, strategyLazy2}, // level 9
|
|
{22, 20, 21, 4, 5, 16, strategyLazy2}, // level 10
|
|
{22, 21, 22, 4, 5, 16, strategyLazy2}, // level 11
|
|
{22, 21, 22, 5, 5, 16, strategyLazy2}, // level 12
|
|
{22, 21, 22, 5, 5, 32, strategyBtlazy2}, // level 13
|
|
{22, 22, 23, 5, 5, 32, strategyBtlazy2}, // level 14
|
|
{22, 23, 23, 6, 5, 32, strategyBtlazy2}, // level 15
|
|
{22, 22, 22, 5, 5, 48, strategyBtopt}, // level 16
|
|
{23, 23, 22, 5, 4, 64, strategyBtopt}, // level 17
|
|
{23, 23, 22, 6, 3, 64, strategyBtultra}, // level 18
|
|
{23, 24, 22, 7, 3, 256, strategyBtultra2}, // level 19
|
|
{25, 25, 23, 7, 3, 256, strategyBtultra2}, // level 20
|
|
{26, 26, 24, 7, 3, 512, strategyBtultra2}, // level 21
|
|
{27, 27, 25, 9, 3, 999, strategyBtultra2}, // level 22
|
|
},
|
|
{ // for srcSize <= 256 KB
|
|
// W, C, H, S, L, T, strat
|
|
{18, 12, 13, 1, 5, 1, strategyFast}, // base for negative levels
|
|
{18, 13, 14, 1, 6, 0, strategyFast}, // level 1
|
|
{18, 14, 14, 1, 5, 1, strategyDfast}, // level 2
|
|
{18, 16, 16, 1, 4, 1, strategyDfast}, // level 3
|
|
{18, 16, 17, 2, 5, 2, strategyGreedy}, // level 4.
|
|
{18, 18, 18, 3, 5, 2, strategyGreedy}, // level 5.
|
|
{18, 18, 19, 3, 5, 4, strategyLazy}, // level 6.
|
|
{18, 18, 19, 4, 4, 4, strategyLazy}, // level 7
|
|
{18, 18, 19, 4, 4, 8, strategyLazy2}, // level 8
|
|
{18, 18, 19, 5, 4, 8, strategyLazy2}, // level 9
|
|
{18, 18, 19, 6, 4, 8, strategyLazy2}, // level 10
|
|
{18, 18, 19, 5, 4, 12, strategyBtlazy2}, // level 11.
|
|
{18, 19, 19, 7, 4, 12, strategyBtlazy2}, // level 12.
|
|
{18, 18, 19, 4, 4, 16, strategyBtopt}, // level 13
|
|
{18, 18, 19, 4, 3, 32, strategyBtopt}, // level 14.
|
|
{18, 18, 19, 6, 3, 128, strategyBtopt}, // level 15.
|
|
{18, 19, 19, 6, 3, 128, strategyBtultra}, // level 16.
|
|
{18, 19, 19, 8, 3, 256, strategyBtultra}, // level 17.
|
|
{18, 19, 19, 6, 3, 128, strategyBtultra2}, // level 18.
|
|
{18, 19, 19, 8, 3, 256, strategyBtultra2}, // level 19.
|
|
{18, 19, 19, 10, 3, 512, strategyBtultra2}, // level 20.
|
|
{18, 19, 19, 12, 3, 512, strategyBtultra2}, // level 21.
|
|
{18, 19, 19, 13, 3, 999, strategyBtultra2}, // level 22.
|
|
},
|
|
{ // for srcSize <= 128 KB
|
|
// W, C, H, S, L, T, strat
|
|
{17, 12, 12, 1, 5, 1, strategyFast}, // base for negative levels
|
|
{17, 12, 13, 1, 6, 0, strategyFast}, // level 1
|
|
{17, 13, 15, 1, 5, 0, strategyFast}, // level 2
|
|
{17, 15, 16, 2, 5, 1, strategyDfast}, // level 3
|
|
{17, 17, 17, 2, 4, 1, strategyDfast}, // level 4
|
|
{17, 16, 17, 3, 4, 2, strategyGreedy}, // level 5
|
|
{17, 17, 17, 3, 4, 4, strategyLazy}, // level 6
|
|
{17, 17, 17, 3, 4, 8, strategyLazy2}, // level 7
|
|
{17, 17, 17, 4, 4, 8, strategyLazy2}, // level 8
|
|
{17, 17, 17, 5, 4, 8, strategyLazy2}, // level 9
|
|
{17, 17, 17, 6, 4, 8, strategyLazy2}, // level 10
|
|
{17, 17, 17, 5, 4, 8, strategyBtlazy2}, // level 11
|
|
{17, 18, 17, 7, 4, 12, strategyBtlazy2}, // level 12
|
|
{17, 18, 17, 3, 4, 12, strategyBtopt}, // level 13.
|
|
{17, 18, 17, 4, 3, 32, strategyBtopt}, // level 14.
|
|
{17, 18, 17, 6, 3, 256, strategyBtopt}, // level 15.
|
|
{17, 18, 17, 6, 3, 128, strategyBtultra}, // level 16.
|
|
{17, 18, 17, 8, 3, 256, strategyBtultra}, // level 17.
|
|
{17, 18, 17, 10, 3, 512, strategyBtultra}, // level 18.
|
|
{17, 18, 17, 5, 3, 256, strategyBtultra2}, // level 19.
|
|
{17, 18, 17, 7, 3, 512, strategyBtultra2}, // level 20.
|
|
{17, 18, 17, 9, 3, 512, strategyBtultra2}, // level 21.
|
|
{17, 18, 17, 11, 3, 999, strategyBtultra2}, // level 22.
|
|
},
|
|
{ // for srcSize <= 16 KB
|
|
// W, C, H, S, L, T, strat
|
|
{14, 12, 13, 1, 5, 1, strategyFast}, // base for negative levels
|
|
{14, 14, 15, 1, 5, 0, strategyFast}, // level 1
|
|
{14, 14, 15, 1, 4, 0, strategyFast}, // level 2
|
|
{14, 14, 15, 2, 4, 1, strategyDfast}, // level 3
|
|
{14, 14, 14, 4, 4, 2, strategyGreedy}, // level 4
|
|
{14, 14, 14, 3, 4, 4, strategyLazy}, // level 5.
|
|
{14, 14, 14, 4, 4, 8, strategyLazy2}, // level 6
|
|
{14, 14, 14, 6, 4, 8, strategyLazy2}, // level 7
|
|
{14, 14, 14, 8, 4, 8, strategyLazy2}, // level 8.
|
|
{14, 15, 14, 5, 4, 8, strategyBtlazy2}, // level 9.
|
|
{14, 15, 14, 9, 4, 8, strategyBtlazy2}, // level 10.
|
|
{14, 15, 14, 3, 4, 12, strategyBtopt}, // level 11.
|
|
{14, 15, 14, 4, 3, 24, strategyBtopt}, // level 12.
|
|
{14, 15, 14, 5, 3, 32, strategyBtultra}, // level 13.
|
|
{14, 15, 15, 6, 3, 64, strategyBtultra}, // level 14.
|
|
{14, 15, 15, 7, 3, 256, strategyBtultra}, // level 15.
|
|
{14, 15, 15, 5, 3, 48, strategyBtultra2}, // level 16.
|
|
{14, 15, 15, 6, 3, 128, strategyBtultra2}, // level 17.
|
|
{14, 15, 15, 7, 3, 256, strategyBtultra2}, // level 18.
|
|
{14, 15, 15, 8, 3, 256, strategyBtultra2}, // level 19.
|
|
{14, 15, 15, 8, 3, 512, strategyBtultra2}, // level 20.
|
|
{14, 15, 15, 9, 3, 512, strategyBtultra2}, // level 21.
|
|
{14, 15, 15, 10, 3, 999, strategyBtultra2}, // level 22.
|
|
},
|
|
}
|
|
*/
|