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Add new formula for match buffer size

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conor42
2019-03-29 00:14:51 +10:00
parent 80ae5388ad
commit b01ec364eb
1 changed files with 28 additions and 18 deletions
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46
CPP/7zip/UI/GUI/CompressDialog.cpp
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@@ -1410,33 +1410,34 @@ typedef enum {
} FL2_strategy; } FL2_strategy;
typedef struct { typedef struct {
UInt32 dictionarySize; /* largest match distance : larger == more compression, more memory needed during decompression; >= 27 == more memory per byte, slower */ UInt32 dictionarySize; /* largest match distance : larger == more compression, more memory needed during decompression; > 64Mb == more memory per byte, slower */
unsigned overlapFraction; /* overlap between consecutive blocks in 1/16 units: larger == more compression, slower */ unsigned overlapFraction; /* overlap between consecutive blocks in 1/16 units: larger == more compression, slower */
unsigned chainLog; /* fully searched segment : larger == more compression, slower, more memory; hybrid mode only (ultra) */ unsigned chainLog; /* HC3 sliding window : larger == more compression, slower; hybrid mode only (ultra) */
unsigned searchLog; /* nb of searches : larger == more compression, slower; hybrid mode only (ultra) */ unsigned cyclesLog; /* nb of searches : larger == more compression, slower; hybrid mode only (ultra) */
unsigned searchDepth; /* maximum depth for resolving string matches : larger == more compression, slower; >= 64 == more memory, slower */ unsigned searchDepth; /* maximum depth for resolving string matches : larger == more compression, slower */
unsigned fastLength; /* acceptable match size for parser, not less than searchDepth : larger == more compression, slower; fast bytes parameter from 7-zip */ unsigned fastLength; /* acceptable match size for parser : larger == more compression, slower; fast bytes parameter from 7-Zip */
unsigned divideAndConquer; /* split long chains of 2-byte matches into shorter chains with a small overlap : faster, somewhat less compression; enabled by default */ unsigned divideAndConquer; /* split long chains of 2-byte matches into shorter chains with a small overlap : faster, somewhat less compression; enabled by default */
unsigned bufferLog; /* buffer size for processing match chains is (dictionaryLog - bufferLog) : when divideAndConquer enabled, affects compression; */
/* when divideAndConquer disabled, affects speed in a hardware-dependent manner */
FL2_strategy strategy; /* encoder strategy : fast, optimized or ultra (hybrid) */ FL2_strategy strategy; /* encoder strategy : fast, optimized or ultra (hybrid) */
} FL2_compressionParameters; } FL2_compressionParameters;
#define FL2_MAX_7Z_CLEVEL 9 #define FL2_MAX_7Z_CLEVEL 9
#define MATCH_BUFFER_SHIFT 8;
#define MATCH_BUFFER_ELBOW_BITS 17
#define MATCH_BUFFER_ELBOW (1UL << MATCH_BUFFER_ELBOW_BITS)
#define MB *(1U<<20) #define MB *(1U<<20)
static const FL2_compressionParameters FL2_7zCParameters[FL2_MAX_7Z_CLEVEL + 1] = { static const FL2_compressionParameters FL2_7zCParameters[FL2_MAX_7Z_CLEVEL + 1] = {
{ 0,0,0,0,0,0,0,0,FL2_fast }, { 0,0,0,0,0,0,0,FL2_fast },
{ 1 MB, 1, 7, 0, 6, 32, 1, 4, FL2_fast }, /* 1 */ { 1 MB, 1, 7, 0, 6, 32, 1, FL2_fast }, /* 1 */
{ 2 MB, 2, 7, 0, 10, 32, 1, 4, FL2_fast }, /* 2 */ { 2 MB, 2, 7, 0, 10, 32, 1, FL2_fast }, /* 2 */
{ 2 MB, 2, 7, 0, 10, 32, 1, 4, FL2_opt }, /* 3 */ { 2 MB, 2, 7, 0, 10, 32, 1, FL2_opt }, /* 3 */
{ 4 MB, 2, 7, 0, 14, 32, 1, 4, FL2_opt }, /* 4 */ { 4 MB, 2, 7, 0, 14, 32, 1, FL2_opt }, /* 4 */
{ 16 MB, 2, 9, 0, 42, 48, 1, 4, FL2_ultra }, /* 5 */ { 16 MB, 2, 9, 0, 42, 48, 1, FL2_ultra }, /* 5 */
{ 32 MB, 2, 10, 0, 50, 64, 1, 4, FL2_ultra }, /* 6 */ { 32 MB, 2, 10, 0, 50, 64, 1, FL2_ultra }, /* 6 */
{ 64 MB, 2, 11, 1, 62, 96, 1, 3, FL2_ultra }, /* 7 */ { 64 MB, 2, 11, 1, 62, 96, 1, FL2_ultra }, /* 7 */
{ 64 MB, 4, 12, 2, 90, 273, 1, 3, FL2_ultra }, /* 8 */ { 64 MB, 4, 12, 2, 90, 273, 1, FL2_ultra }, /* 8 */
{ 128 MB, 2, 14, 3, 254, 273, 0, 2, FL2_ultra } /* 9 */ { 128 MB, 2, 14, 3, 254, 273, 0, FL2_ultra } /* 9 */
}; };
#undef MB #undef MB
@@ -2026,7 +2027,16 @@ UInt64 CCompressDialog::GetMemoryUsage(UInt32 dict, UInt64 &decompressMemory)
level = FL2_MAX_7Z_CLEVEL; level = FL2_MAX_7Z_CLEVEL;
/* dual buffer is enabled in Lzma2Encoder.cpp so size is dict * 6 */ /* dual buffer is enabled in Lzma2Encoder.cpp so size is dict * 6 */
size += dict * 6 + (1UL << 18) * numThreads; size += dict * 6 + (1UL << 18) * numThreads;
UInt32 bufSize = dict >> (12 - FL2_7zCParameters[level].bufferLog); UInt32 bufSize = dict >> MATCH_BUFFER_SHIFT;
if (bufSize > MATCH_BUFFER_ELBOW) {
UInt32 extra = 0;
unsigned n = MATCH_BUFFER_ELBOW_BITS - 1;
for (; (4UL << n) <= bufSize; ++n)
extra += MATCH_BUFFER_ELBOW >> 4;
if ((3UL << n) <= bufSize)
extra += MATCH_BUFFER_ELBOW >> 5;
bufSize = MATCH_BUFFER_ELBOW + extra;
}
size += (bufSize * 12 + RMF_BUILDER_SIZE) * numThreads; size += (bufSize * 12 + RMF_BUILDER_SIZE) * numThreads;
if (dict > (UInt32(1) << 26)) if (dict > (UInt32(1) << 26))
size += dict; size += dict;