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merged repcode search into BT match search

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this version has same speed as branch `opt`
which is itself 5-10% slower than branch `dev`
(no identified reason)

It does not compress exactly the same as `opt` or `dev`,
maybe because it doesn't stop search after repcodes,
leading to sometimes better compression, sometimes worse
(by a small margin).

warning : _extDict path does not work for the time being
This means that benchmark module works,
but file module will fail with large files (and high compression level).
Objective is to fuse _extDict path into current one,
in order to have a single parser to maintain.
This commit is contained in:
Yann Collet 2017-11-13 02:19:36 -08:00
parent 72c0f4574c
commit 9a11f70dc3
6 changed files with 197 additions and 174 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/common/zstd_common.c
View File

@ -46,6 +46,12 @@ ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }
* provides error code string from enum */
const char* ZSTD_getErrorString(ZSTD_ErrorCode code) { return ERR_getErrorString(code); }
/*! g_debuglog_enable :
* turn on/off debug traces (global switch) */
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 2)
int g_debuglog_enable = 1;
#endif
/*=**************************************************************
* Custom allocator

5
lib/common/zstd_internal.h
View File

@ -54,6 +54,7 @@ extern "C" {
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG>=2)
# include <stdio.h>
extern int g_debuglog_enable;
/* recommended values for ZSTD_DEBUG display levels :
* 1 : no display, enables assert() only
* 2 : reserved for currently active debugging path
@ -62,7 +63,7 @@ extern "C" {
* 5 : events once per block
* 6 : events once per sequence (*very* verbose) */
# define DEBUGLOG(l, ...) { \
if (l<=ZSTD_DEBUG) { \
if ((g_debuglog_enable) & (l<=ZSTD_DEBUG)) { \
fprintf(stderr, __FILE__ ": "); \
fprintf(stderr, __VA_ARGS__); \
fprintf(stderr, " \n"); \
@ -89,9 +90,7 @@ extern "C" {
#define ZSTD_OPT_NUM (1<<12)
#define ZSTD_REP_NUM 3 /* number of repcodes */
#define ZSTD_REP_CHECK (ZSTD_REP_NUM) /* number of repcodes to check by the optimal parser */
#define ZSTD_REP_MOVE (ZSTD_REP_NUM-1)
#define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)
static const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };
#define KB *(1 <<10)

18
lib/compress/zstd_compress.c
View File

@ -42,17 +42,6 @@ size_t ZSTD_compressBound(size_t srcSize) {
}
/*-*************************************
* Sequence storage
***************************************/
static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
{
ssPtr->lit = ssPtr->litStart;
ssPtr->sequences = ssPtr->sequencesStart;
ssPtr->longLengthID = 0;
}
/*-*************************************
* Context memory management
***************************************/
@ -1606,6 +1595,13 @@ static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
seqStorePtr->lit += lastLLSize;
}
static void ZSTD_resetSeqStore(seqStore_t* ssPtr)
{
ssPtr->lit = ssPtr->litStart;
ssPtr->sequences = ssPtr->sequencesStart;
ssPtr->longLengthID = 0;
}
static size_t ZSTD_compressBlock_internal(ZSTD_CCtx* zc, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
DEBUGLOG(5, "ZSTD_compressBlock_internal : dstCapacity = %u", (U32)dstCapacity);

9
lib/compress/zstd_compress_internal.h
View File

@ -233,13 +233,14 @@ MEM_STATIC U32 ZSTD_MLcode(U32 mlBase)
*/
MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t mlBase)
{
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 6)
#if defined(ZSTD_DEBUG) && (ZSTD_DEBUG >= 2)
static const BYTE* g_start = NULL;
U32 const pos = (U32)((const BYTE*)literals - g_start);
if (g_start==NULL) g_start = (const BYTE*)literals; /* note : index only works for compression within a single segment */
if ((pos > 0) && (pos < 1000000000))
DEBUGLOG(6, "Cpos %6u :%5u literals & match %3u bytes at distance %6u",
{ U32 const pos = (U32)((const BYTE*)literals - g_start);
g_debuglog_enable = ((pos >= 1622540) & (pos < 1622575));
DEBUGLOG(2, "Cpos%7u :%3u literals, match%3u bytes at distance%7u",
pos, (U32)litLength, (U32)mlBase+MINMATCH, (U32)offsetCode);
}
#endif
/* copy Literals */
assert(seqStorePtr->lit + litLength <= seqStorePtr->litStart + 128 KB);

313
lib/compress/zstd_opt.c
View File

@ -17,6 +17,10 @@
#define ZSTD_FREQ_DIV 4 /* log factor when using previous stats to init next stats */
#define ZSTD_MAX_PRICE (1<<30)
#define ZSTD_REP_CHECK (ZSTD_REP_NUM) /* number of repcodes to check by the optimal parser */
#define ZSTD_REP_MOVE_OPT (ZSTD_REP_NUM)
/*-*************************************
* Price functions for optimal parser
***************************************/
@ -95,7 +99,7 @@ static void ZSTD_rescaleFreqs(optState_t* optPtr, const BYTE* src, size_t srcSiz
}
static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 litLength, const BYTE* literals)
static U32 ZSTD_getLiteralPrice(optState_t* optPtr, U32 const litLength, const BYTE* literals)
{
U32 price;
@ -154,7 +158,9 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_getPrice(optState_t* optPtr, U32 litLength, const
price += ML_bits[mlCode] + optPtr->log2matchLengthSum - ZSTD_highbit32(optPtr->matchLengthFreq[mlCode]+1);
}
return price + ZSTD_getLiteralPrice(optPtr, litLength, literals) + optPtr->factor;
price += ZSTD_getLiteralPrice(optPtr, litLength, literals) + optPtr->factor;
DEBUGLOG(7, "ZSTD_getPrice(ll:%u, ml:%u) = %u", litLength, matchLength, price);
return price;
}
@ -190,17 +196,6 @@ static void ZSTD_updatePrice(optState_t* optPtr, U32 litLength, const BYTE* lite
}
/* update opt[pos] and last_pos */
#define SET_PRICE(pos, mlen_, offset_, litlen_, price_) \
{ \
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
opt[pos].mlen = mlen_; \
opt[pos].off = offset_; \
opt[pos].litlen = litlen_; \
opt[pos].price = price_; \
}
/* function safe only for comparisons */
static U32 ZSTD_readMINMATCH(const void* memPtr, U32 length)
{
@ -242,13 +237,15 @@ static U32 ZSTD_insertAndFindFirstIndexHash3 (ZSTD_CCtx* zc, const BYTE* ip)
static U32 ZSTD_insertBtAndGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
U32 nbCompares, const U32 mls,
U32 extDict, ZSTD_match_t* matches, const U32 minMatchLen)
U32 nbCompares, U32 const mls, U32 const extDict,
U32 rep[ZSTD_REP_NUM], U32 const ll0,
ZSTD_match_t* matches, const U32 minMatchLen)
{
const BYTE* const base = zc->base;
const U32 current = (U32)(ip-base);
const U32 hashLog = zc->appliedParams.cParams.hashLog;
const size_t h = ZSTD_hashPtr(ip, hashLog, mls);
U32 const minMatch = (mls==3) ? 3 : 4;
U32* const hashTable = zc->hashTable;
U32 matchIndex = hashTable[h];
U32* const bt = zc->chainTable;
@ -267,10 +264,29 @@ static U32 ZSTD_insertBtAndGetAllMatches (
U32 dummy32; /* to be nullified at the end */
U32 mnum = 0;
const U32 minMatch = (mls == 3) ? 3 : 4;
size_t bestLength = minMatchLen-1;
if (minMatch == 3) { /* HC3 match finder */
/* check repCode */
{ U32 const lastR = ZSTD_REP_NUM + ll0;
U32 repCode;
for (repCode = ll0; repCode < lastR; repCode++) {
S32 const repOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
if ( (repOffset > 0)
&& (repOffset < (S32)(ip-prefixStart)) /* within current mem segment */
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch))) {
U32 const repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iLimit) + minMatch;
/* save better solution */
if (repLen > bestLength) {
bestLength = repLen;
matches[mnum].off = repCode - ll0;
matches[mnum].len = (U32)repLen;
mnum++;
if (repLen > ZSTD_OPT_NUM) goto update;
if (ip+repLen == iLimit) goto update; /* best possible, and avoid read overflow*/
}
} } }
if (mls == 3) { /* HC3 match finder */
U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3 (zc, ip);
if (matchIndex3>windowLow && (current - matchIndex3 < (1<<18))) {
const BYTE* match;
@ -287,7 +303,7 @@ static U32 ZSTD_insertBtAndGetAllMatches (
/* save best solution */
if (currentMl > bestLength) {
bestLength = currentMl;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex3;
matches[mnum].off = ZSTD_REP_MOVE + current - matchIndex3;
matches[mnum].len = (U32)currentMl;
mnum++;
if (currentMl > ZSTD_OPT_NUM) goto update;
@ -318,12 +334,12 @@ static U32 ZSTD_insertBtAndGetAllMatches (
if (matchLength > bestLength) {
if (matchLength > matchEndIdx - matchIndex) matchEndIdx = matchIndex + (U32)matchLength;
bestLength = matchLength;
matches[mnum].off = ZSTD_REP_MOVE_OPT + current - matchIndex;
matches[mnum].off = ZSTD_REP_MOVE + current - matchIndex;
matches[mnum].len = (U32)matchLength;
mnum++;
if (matchLength > ZSTD_OPT_NUM) break;
if (ip+matchLength == iLimit) /* equal : no way to know if inf or sup */
break; /* drop, to guarantee consistency (miss a little bit of compression) */
break; /* drop, to preserve bt consistency (miss a little bit of compression) */
}
if (match[matchLength] < ip[matchLength]) {
@ -345,7 +361,7 @@ static U32 ZSTD_insertBtAndGetAllMatches (
*smallerPtr = *largerPtr = 0;
update:
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1;
zc->nextToUpdate = (matchEndIdx > current + 8) ? matchEndIdx - 8 : current+1; /* skip repetitive patterns */
return mnum;
}
@ -354,27 +370,31 @@ update:
static U32 ZSTD_BtGetAllMatches (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
const U32 maxNbAttempts, const U32 mls,
U32 rep[ZSTD_REP_NUM], U32 const ll0,
ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, rep, ll0, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
const U32 maxNbAttempts, const U32 matchLengthSearch,
U32 rep[ZSTD_REP_NUM], U32 const ll0,
ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
case 3 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, rep, ll0, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 4 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, rep, ll0, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, rep, ll0, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
case 6 : return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, rep, ll0, matches, minMatchLen);
}
}
@ -382,27 +402,31 @@ static U32 ZSTD_BtGetAllMatches_selectMLS (
static U32 ZSTD_BtGetAllMatches_extDict (
ZSTD_CCtx* zc,
const BYTE* const ip, const BYTE* const iLimit,
const U32 maxNbAttempts, const U32 mls, ZSTD_match_t* matches, const U32 minMatchLen)
const U32 maxNbAttempts, const U32 mls,
U32 rep[ZSTD_REP_NUM], U32 const ll0,
ZSTD_match_t* matches, const U32 minMatchLen)
{
if (ip < zc->base + zc->nextToUpdate) return 0; /* skipped area */
ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen);
return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, rep, ll0, matches, minMatchLen);
}
static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
ZSTD_CCtx* zc, /* Index table will be updated */
const BYTE* ip, const BYTE* const iHighLimit,
const U32 maxNbAttempts, const U32 matchLengthSearch, ZSTD_match_t* matches, const U32 minMatchLen)
const U32 maxNbAttempts, const U32 matchLengthSearch,
U32 rep[ZSTD_REP_NUM], U32 const ll0,
ZSTD_match_t* matches, const U32 minMatchLen)
{
switch(matchLengthSearch)
{
case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
case 3 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, rep, ll0, matches, minMatchLen);
default :
case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
case 4 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, rep, ll0, matches, minMatchLen);
case 5 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, rep, ll0, matches, minMatchLen);
case 7 :
case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
case 6 : return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, rep, ll0, matches, minMatchLen);
}
}
@ -410,6 +434,42 @@ static U32 ZSTD_BtGetAllMatches_selectMLS_extDict (
/*-*******************************
* Optimal parser
*********************************/
typedef struct repcodes_s {
U32 rep[3];
} repcodes_t;
repcodes_t ZSTD_updateRep(U32 const rep[3], U32 const offset, U32 const ll0)
{
repcodes_t newReps;
if (offset >= ZSTD_REP_NUM) { /* full offset */
newReps.rep[2] = rep[1];
newReps.rep[1] = rep[0];
newReps.rep[0] = offset - ZSTD_REP_MOVE;
} else { /* repcode */
U32 const repCode = offset + ll0;
if (repCode > 0) { /* note : if repCode==0, no change */
U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
newReps.rep[2] = (repCode >= 2) ? rep[1] : rep[2];
newReps.rep[1] = rep[0];
newReps.rep[0] = currentOffset;
} else { /* repCode == 0 */
memcpy(&newReps, rep, sizeof(newReps));
}
}
return newReps;
}
/* update opt[pos] and last_pos */
#define SET_PRICE(pos, mlen_, offset_, litlen_, price_, rep_) \
{ \
while (last_pos < pos) { opt[last_pos+1].price = ZSTD_MAX_PRICE; last_pos++; } \
opt[pos].mlen = mlen_; \
opt[pos].off = offset_; \
opt[pos].litlen = litlen_; \
opt[pos].price = price_; \
memcpy(opt[pos].rep, &rep_, sizeof(rep_)); \
}
FORCE_INLINE_TEMPLATE
size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
const void* src, size_t srcSize, const int ultra)
@ -444,57 +504,49 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
U32 cur, last_pos = 0;
U32 best_mlen, best_off;
U32 const initLL = (U32)(ip - anchor);
/* find first match */
memset(opt, 0, sizeof(ZSTD_optimal_t));
/* check repCode */
{ U32 const ll0 = !initLL;
U32 const lastR = ZSTD_REP_CHECK + ll0;
U32 repCode;
for (repCode = ll0; repCode < lastR; repCode++) {
S32 const repOffset = (repCode==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[repCode];
if ( (repOffset > 0)
&& (repOffset < (S32)(ip-prefixStart)) /* within current mem segment */
&& (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repOffset, minMatch))) {
U32 repLen = (U32)ZSTD_count(ip+minMatch, ip+minMatch-repOffset, iend) + minMatch;
if (repLen > sufficient_len) {
/* large repMatch => immediate encoding */
best_mlen = repLen; best_off = repCode; cur = 0; last_pos = 1;
goto _shortestPath;
}
do {
U32 const repPrice = ZSTD_getPrice(optStatePtr, initLL, anchor, repCode - ll0, repLen, ultra);
if (repLen > last_pos || repPrice < opt[repLen].price)
SET_PRICE(repLen, repLen, repCode, initLL, repPrice); /* note : macro modifies last_pos */
repLen--;
} while (repLen >= minMatch);
} } }
U32 const nb_matches = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, rep, ll0, matches, minMatch);
{ U32 const nb_matches = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch);
if (!nb_matches /*no match*/) { ip++; continue; }
DEBUGLOG(7, "found %u matches of maxLength=%u and offset=%u at cPos=%u => start new serie",
nb_matches, matches[nb_matches-1].len, matches[nb_matches-1].off, (U32)(ip-prefixStart));
if (!last_pos /*no repCode*/ && !nb_matches /*no match*/) { ip++; continue; }
if (nb_matches && (matches[nb_matches-1].len > sufficient_len)) {
/* large match => immediate encoding */
if (matches[nb_matches-1].len > sufficient_len) {
best_mlen = matches[nb_matches-1].len;
best_off = matches[nb_matches-1].off;
DEBUGLOG(7, "large match (%u>%u), immediate encoding",
best_mlen, sufficient_len);
cur = 0;
last_pos = 1;
goto _shortestPath;
}
/* set prices for first matches from position == 0 */
{ U32 matchNb;
U32 pos = last_pos /*some repCode (assumed cheaper)*/ ? last_pos : minMatch;
{ U32 pos = minMatch;
U32 matchNb;
for (matchNb = 0; matchNb < nb_matches; matchNb++) {
U32 const offset = matches[matchNb].off;
U32 const end = matches[matchNb].len;
repcodes_t repMatch = ZSTD_updateRep(rep, offset, ll0);
DEBUGLOG(7, "match %u: starting reps=%u,%u,%u ==> %u,%u,%u",
matchNb, rep[0], rep[1], rep[2], repMatch.rep[0], repMatch.rep[1], repMatch.rep[2])
while (pos <= end) {
U32 const matchPrice = ZSTD_getPrice(optStatePtr, initLL, anchor, matches[matchNb].off-1, pos, ultra);
if (pos > last_pos || matchPrice < opt[pos].price)
SET_PRICE(pos, pos, matches[matchNb].off, initLL, matchPrice); /* note : macro modifies last_pos */
U32 const matchPrice = ZSTD_getPrice(optStatePtr, initLL, anchor, offset, pos, ultra);
if (pos > last_pos || matchPrice < opt[pos].price) {
DEBUGLOG(7, "rPos:%u => set initial price : %u",
pos, matchPrice);
DEBUGLOG(7, "transferring rep:%u,%u,%u",
repMatch.rep[0], repMatch.rep[1], repMatch.rep[2]);
SET_PRICE(pos, pos, offset, initLL, matchPrice, repMatch); /* note : macro modifies last_pos */
}
pos++;
} } } }
if (last_pos < minMatch) { ip++; continue; }
assert(last_pos >= minMatch);
/* initialize opt[0] */
{ U32 i ; for (i=0; i<ZSTD_REP_NUM; i++) opt[0].rep[i] = rep[i]; }
@ -514,74 +566,28 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
} else {
price = ZSTD_getLiteralPrice(optStatePtr, litlen, anchor);
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price); /* note : macro modifies last_pos */
}
if (price <= opt[cur].price) {
DEBUGLOG(7, "rPos:%u : better price (%u<%u) using literal",
cur, price, opt[cur].price);
DEBUGLOG(7, "transferring rep:%u,%u,%u",
opt[cur-1].rep[0], opt[cur-1].rep[1], opt[cur-1].rep[2]);
SET_PRICE(cur, 1, 0, litlen, price, opt[cur-1].rep); /* note : macro modifies last_pos */
} }
if (cur == last_pos) break;
/* last match must start at a minimum distance of 8 from oend */
if (inr > ilimit) continue;
/* update repcodes */
{ U32 const mlen = opt[cur].mlen;
if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
opt[cur].rep[2] = opt[cur-mlen].rep[1];
opt[cur].rep[1] = opt[cur-mlen].rep[0];
opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
} else {
opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur-mlen].rep[1] : opt[cur-mlen].rep[2];
opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur-mlen].rep[0] : opt[cur-mlen].rep[1];
/* If opt[cur].off == ZSTD_REP_MOVE_OPT, then mlen != 1.
* offset ZSTD_REP_MOVE_OPT is used for the special case
* litLength == 0, where offset 0 means something special.
* mlen == 1 means the previous byte was stored as a literal,
* so they are mutually exclusive.
*/
assert(!(opt[cur].off == ZSTD_REP_MOVE_OPT && mlen == 1));
opt[cur].rep[0] = (opt[cur].off == ZSTD_REP_MOVE_OPT) ? (opt[cur-mlen].rep[0] - 1) : (opt[cur-mlen].rep[opt[cur].off]);
} }
best_mlen = minMatch;
{ U32 const ll0 = (opt[cur].mlen != 1);
U32 const lastR = ZSTD_REP_CHECK + ll0;
U32 repCode4; /* universal referential */
for (repCode4=ll0; repCode4<lastR; repCode4++) { /* check rep */
const S32 repCur = (repCode4==ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[repCode4];
if ( (repCur > 0) && (repCur < (S32)(inr-prefixStart)) /* within current mem segment */
&& (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) {
U32 matchLength = (U32)ZSTD_count(inr+minMatch, inr+minMatch - repCur, iend) + minMatch;
U32 const repCode3 = repCode4 - ll0; /* contextual referential, depends on ll0 */
assert(repCode3 < 3);
if (matchLength > sufficient_len || cur + matchLength >= ZSTD_OPT_NUM) {
best_mlen = matchLength;
best_off = repCode4;
last_pos = cur + 1;
goto _shortestPath;
}
if (matchLength > best_mlen) best_mlen = matchLength;
do {
U32 const litlen = ll0 ? 0 : opt[cur].litlen;
U32 price;
if (cur > litlen) {
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, inr-litlen, repCode3, matchLength, ultra);
} else {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, repCode3, matchLength, ultra);
}
if (cur + matchLength > last_pos || price <= opt[cur + matchLength].price)
SET_PRICE(cur + matchLength, matchLength, repCode4, litlen, price); /* note : macro modifies last_pos */
matchLength--;
} while (matchLength >= minMatch);
} } }
{ U32 const nb_matches = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen /*largest repLength*/); /* search for matches larger than repcodes */
{ U32 const ll0_cur = (opt[cur].mlen != 1);
U32 const nb_matches = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, opt[cur].rep, ll0_cur, matches, minMatch);
U32 matchNb;
if (!nb_matches) continue;
if (nb_matches > 0 && (matches[nb_matches-1].len > sufficient_len || cur + matches[nb_matches-1].len >= ZSTD_OPT_NUM)) {
DEBUGLOG(7, "rPos:%u, found %u matches, of maxLength=%u",
cur, nb_matches, matches[nb_matches-1].len);
if ( (matches[nb_matches-1].len > sufficient_len)
|| (cur + matches[nb_matches-1].len >= ZSTD_OPT_NUM) ) {
best_mlen = matches[nb_matches-1].len;
best_off = matches[nb_matches-1].off;
last_pos = cur + 1;
@ -590,19 +596,27 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
/* set prices using matches at position = cur */
for (matchNb = 0; matchNb < nb_matches; matchNb++) {
U32 mlen = (matchNb>0) ? matches[matchNb-1].len+1 : best_mlen;
U32 mlen = (matchNb>0) ? matches[matchNb-1].len+1 : minMatch;
U32 const lastML = matches[matchNb].len;
U32 const offset = matches[matchNb].off;
U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0;
repcodes_t const repMatch = ZSTD_updateRep(opt[cur].rep, offset, ll0_cur);
DEBUGLOG(7, "testing match %u => offCode=%u, mlen=%u, llen=%u",
matchNb, matches[matchNb].off, lastML, litlen);
while (mlen <= lastML) {
U32 const litlen = (opt[cur].mlen == 1) ? opt[cur].litlen : 0;
U32 price;
if (cur > litlen)
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, matches[matchNb].off-1, mlen, ultra);
price = opt[cur - litlen].price + ZSTD_getPrice(optStatePtr, litlen, ip+cur-litlen, offset, mlen, ultra);
else
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[matchNb].off-1, mlen, ultra);
price = ZSTD_getPrice(optStatePtr, litlen, anchor, offset, mlen, ultra);
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[matchNb].off, litlen, price); /* note : macro modifies last_pos */
if (cur + mlen > last_pos || (price < opt[cur + mlen].price)) {
DEBUGLOG(7, "rPos:%u => new better price (%u<%u)",
cur+mlen, price, opt[cur+mlen].price);
SET_PRICE(cur + mlen, mlen, offset, litlen, price, repMatch); /* note : macro modifies last_pos */
}
mlen++;
} } } }
@ -610,11 +624,15 @@ size_t ZSTD_compressBlock_opt_generic(ZSTD_CCtx* ctx,
best_mlen = opt[last_pos].mlen;
best_off = opt[last_pos].off;
cur = last_pos - best_mlen;
DEBUGLOG(7, "Preparing path selection : last_pos:%u, cur:%u, best_mlen:%u",
last_pos, cur, best_mlen);
_shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
opt[0].mlen = 1;
/* reverse traversal */
DEBUGLOG(7, "start reverse traversal (last_pos:%u, cur:%u)",
last_pos, cur);
{ U32 selected_matchLength = best_mlen;
U32 selectedOffset = best_off;
U32 pos = cur;
@ -639,23 +657,24 @@ _shortestPath: /* cur, last_pos, best_mlen, best_off have to be set */
pos += mlen;
/* repcodes update */
if (offset > ZSTD_REP_MOVE_OPT) { /* full offset */
if (offset >= ZSTD_REP_NUM) { /* full offset */
rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = offset - ZSTD_REP_MOVE_OPT;
offset--;
rep[0] = offset - ZSTD_REP_MOVE;
} else { /* repcode */
if (offset != 0) {
U32 const currentOffset = (offset==ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[offset];
if (offset != 1) rep[2] = rep[1];
U32 const repCode = offset + (litLength==0);
if (repCode) { /* note : if repCode==0, no change */
U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode];
if (repCode >= 2) rep[2] = rep[1];
rep[1] = rep[0];
rep[0] = currentOffset;
}
if (litLength==0) offset--;
}
ZSTD_updatePrice(optStatePtr, litLength, anchor, offset, mlen);
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen-MINMATCH);
DEBUGLOG(7, "seq: ll:%u,ml:%u,off:%u - rep:%u,%u,%u",
litLength, mlen, offset, rep[0], rep[1], rep[2]);
anchor = ip = ip + mlen;
} }
} /* for (cur=0; cur < last_pos; ) */
@ -747,12 +766,12 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
do {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, best_off, mlen, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
SET_PRICE(mlen, mlen, i, litlen, price, rep); /* note : macro modifies last_pos */
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, rep, (ip == anchor), matches, minMatch); /* first search (depth 0) */
if (!last_pos && !match_num) { ip++; continue; }
@ -777,7 +796,7 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
while (mlen <= best_mlen) {
price = ZSTD_getPrice(optStatePtr, litlen, anchor, matches[u].off-1, mlen, ultra);
if (mlen > last_pos || price < opt[mlen].price)
SET_PRICE(mlen, mlen, matches[u].off, litlen, price);
SET_PRICE(mlen, mlen, matches[u].off, litlen, price, rep);
mlen++;
} }
@ -801,7 +820,7 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
}
if (cur > last_pos || price <= opt[cur].price)
SET_PRICE(cur, 1, 0, litlen, price);
SET_PRICE(cur, 1, 0, litlen, price, rep);
if (cur == last_pos) break;
@ -855,12 +874,12 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
}
if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
SET_PRICE(cur + mlen, mlen, i, litlen, price);
SET_PRICE(cur + mlen, mlen, i, litlen, price, rep);
mlen--;
} while (mlen >= minMatch);
} } }
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch);
match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, opt[cur].rep, (mlen != 1), matches, minMatch);
if (match_num > 0 && (matches[match_num-1].len > sufficient_len || cur + matches[match_num-1].len >= ZSTD_OPT_NUM)) {
best_mlen = matches[match_num-1].len;
@ -887,7 +906,7 @@ size_t ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx* ctx,
}
if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price, rep);
mlen++;
} } } /* for (cur = 1; cur <= last_pos; cur++) */

2
programs/bench.c
View File

@ -416,10 +416,12 @@ static int BMK_benchMem(const void* srcBuffer, size_t srcSize,
DISPLAY("(sample %u, block %u, pos %u) \n", segNb, bNb, pos);
if (u>5) {
int n;
DISPLAY("origin: ");
for (n=-5; n<0; n++) DISPLAY("%02X ", ((const BYTE*)srcBuffer)[u+n]);
DISPLAY(" :%02X: ", ((const BYTE*)srcBuffer)[u]);
for (n=1; n<3; n++) DISPLAY("%02X ", ((const BYTE*)srcBuffer)[u+n]);
DISPLAY(" \n");
DISPLAY("decode: ");
for (n=-5; n<0; n++) DISPLAY("%02X ", ((const BYTE*)resultBuffer)[u+n]);
DISPLAY(" :%02X: ", ((const BYTE*)resultBuffer)[u]);
for (n=1; n<3; n++) DISPLAY("%02X ", ((const BYTE*)resultBuffer)[u+n]);