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Add enum for representing long length ID

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This commit is contained in:
Sen Huang 2021-03-26 10:35:52 -07:00
parent f8ac0ea7ef
commit b1a43455f8
3 changed files with 26 additions and 19 deletions
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19
lib/common/zstd_internal.h
View File

@ -357,6 +357,13 @@ typedef struct seqDef_s {
U16 matchLength; U16 matchLength;
} seqDef; } seqDef;
/* Controls whether seqStore has a single "long" litLength or matchLength. See seqStore_t. */
typedef enum {
ZSTD_llt_none = 0, /* no longLengthType */
ZSTD_llt_literalLength = 1, /* represents a long literal */
ZSTD_llt_matchLength = 2 /* represents a long match */
} ZSTD_longLengthType_e;
typedef struct { typedef struct {
seqDef* sequencesStart; seqDef* sequencesStart;
seqDef* sequences; /* ptr to end of sequences */ seqDef* sequences; /* ptr to end of sequences */
@ -368,12 +375,12 @@ typedef struct {
size_t maxNbSeq; size_t maxNbSeq;
size_t maxNbLit; size_t maxNbLit;
/* longLengthPos and longLengthID to allow us to represent either a single litLength or matchLength /* longLengthPos and longLengthType to allow us to represent either a single litLength or matchLength
* in the seqStore that has a value larger than U16 (if it exists). To do so, we increment * in the seqStore that has a value larger than U16 (if it exists). To do so, we increment
* the existing value of the litLength or matchLength by 0x10000. * the existing value of the litLength or matchLength by 0x10000.
*/ */
U32 longLengthID; /* 0 == no longLength; 1 == Represent the long literal; 2 == Represent the long match; */ ZSTD_longLengthType_e longLengthType;
U32 longLengthPos; /* Index of the sequence to apply long length modification to */ U32 longLengthPos; /* Index of the sequence to apply long length modification to */
} seqStore_t; } seqStore_t;
typedef struct { typedef struct {
@ -383,7 +390,7 @@ typedef struct {
/** /**
* Returns the ZSTD_sequenceLength for the given sequences. It handles the decoding of long sequences * Returns the ZSTD_sequenceLength for the given sequences. It handles the decoding of long sequences
* indicated by longLengthPos and longLengthID, and adds MINMATCH back to matchLength. * indicated by longLengthPos and longLengthType, and adds MINMATCH back to matchLength.
*/ */
MEM_STATIC ZSTD_sequenceLength ZSTD_getSequenceLength(seqStore_t const* seqStore, seqDef const* seq) MEM_STATIC ZSTD_sequenceLength ZSTD_getSequenceLength(seqStore_t const* seqStore, seqDef const* seq)
{ {
@ -391,10 +398,10 @@ MEM_STATIC ZSTD_sequenceLength ZSTD_getSequenceLength(seqStore_t const* seqStore
seqLen.litLength = seq->litLength; seqLen.litLength = seq->litLength;
seqLen.matchLength = seq->matchLength + MINMATCH; seqLen.matchLength = seq->matchLength + MINMATCH;
if (seqStore->longLengthPos == (U32)(seq - seqStore->sequencesStart)) { if (seqStore->longLengthPos == (U32)(seq - seqStore->sequencesStart)) {
if (seqStore->longLengthID == 1) { if (seqStore->longLengthType == ZSTD_llt_literalLength) {
seqLen.litLength += 0xFFFF; seqLen.litLength += 0xFFFF;
} }
if (seqStore->longLengthID == 2) { if (seqStore->longLengthType == ZSTD_llt_matchLength) {
seqLen.matchLength += 0xFFFF; seqLen.matchLength += 0xFFFF;
} }
} }

18
lib/compress/zstd_compress.c
View File

@ -2197,9 +2197,9 @@ void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offset); ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offset);
mlCodeTable[u] = (BYTE)ZSTD_MLcode(mlv); mlCodeTable[u] = (BYTE)ZSTD_MLcode(mlv);
} }
if (seqStorePtr->longLengthID==1) if (seqStorePtr->longLengthType==ZSTD_llt_literalLength)
llCodeTable[seqStorePtr->longLengthPos] = MaxLL; llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
if (seqStorePtr->longLengthID==2) if (seqStorePtr->longLengthType==ZSTD_llt_matchLength)
mlCodeTable[seqStorePtr->longLengthPos] = MaxML; mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
} }
@ -2571,7 +2571,7 @@ void ZSTD_resetSeqStore(seqStore_t* ssPtr)
{ {
ssPtr->lit = ssPtr->litStart; ssPtr->lit = ssPtr->litStart;
ssPtr->sequences = ssPtr->sequencesStart; ssPtr->sequences = ssPtr->sequencesStart;
ssPtr->longLengthID = 0; ssPtr->longLengthType = ZSTD_llt_none;
} }
typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e; typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e;
@ -2677,9 +2677,9 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
outSeqs[i].rep = 0; outSeqs[i].rep = 0;
if (i == seqStore->longLengthPos) { if (i == seqStore->longLengthPos) {
if (seqStore->longLengthID == 1) { if (seqStore->longLengthType == ZSTD_llt_literalLength) {
outSeqs[i].litLength += 0x10000; outSeqs[i].litLength += 0x10000;
} else if (seqStore->longLengthID == 2) { } else if (seqStore->longLengthType == ZSTD_llt_matchLength) {
outSeqs[i].matchLength += 0x10000; outSeqs[i].matchLength += 0x10000;
} }
} }
@ -3116,7 +3116,7 @@ static size_t ZSTD_countSeqStoreLiteralsBytes(const seqStore_t* const seqStore)
for (i = 0; i < nbSeqs; ++i) { for (i = 0; i < nbSeqs; ++i) {
seqDef seq = seqStore->sequencesStart[i]; seqDef seq = seqStore->sequencesStart[i];
literalsBytes += seq.litLength; literalsBytes += seq.litLength;
if (i == seqStore->longLengthPos && seqStore->longLengthID == 1) { if (i == seqStore->longLengthPos && seqStore->longLengthType == ZSTD_llt_literalLength) {
literalsBytes += 0x10000; literalsBytes += 0x10000;
} }
} }
@ -3131,7 +3131,7 @@ static size_t ZSTD_countSeqStoreMatchBytes(const seqStore_t* const seqStore) {
for (i = 0; i < nbSeqs; ++i) { for (i = 0; i < nbSeqs; ++i) {
seqDef seq = seqStore->sequencesStart[i]; seqDef seq = seqStore->sequencesStart[i];
matchBytes += seq.matchLength + MINMATCH; matchBytes += seq.matchLength + MINMATCH;
if (i == seqStore->longLengthPos && seqStore->longLengthID == 2) { if (i == seqStore->longLengthPos && seqStore->longLengthType == ZSTD_llt_matchLength) {
matchBytes += 0x10000; matchBytes += 0x10000;
} }
} }
@ -3155,9 +3155,9 @@ static void ZSTD_deriveSeqStoreChunk(seqStore_t* resultSeqStore,
} }
/* Move longLengthPos into the correct position if necessary */ /* Move longLengthPos into the correct position if necessary */
if (originalSeqStore->longLengthID != 0) { if (originalSeqStore->longLengthType != ZSTD_llt_none) {
if (originalSeqStore->longLengthPos < startIdx || originalSeqStore->longLengthPos > endIdx) { if (originalSeqStore->longLengthPos < startIdx || originalSeqStore->longLengthPos > endIdx) {
resultSeqStore->longLengthID = 0; resultSeqStore->longLengthType = ZSTD_llt_none;
} else { } else {
resultSeqStore->longLengthPos -= (U32)startIdx; resultSeqStore->longLengthPos -= (U32)startIdx;
} }

8
lib/compress/zstd_compress_internal.h
View File

@ -597,8 +597,8 @@ void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* litera
/* literal Length */ /* literal Length */
if (litLength>0xFFFF) { if (litLength>0xFFFF) {
assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */ assert(seqStorePtr->longLengthType == ZSTD_llt_none); /* there can only be a single long length */
seqStorePtr->longLengthID = 1; seqStorePtr->longLengthType = ZSTD_llt_literalLength;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
} }
seqStorePtr->sequences[0].litLength = (U16)litLength; seqStorePtr->sequences[0].litLength = (U16)litLength;
@ -608,8 +608,8 @@ void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* litera
/* match Length */ /* match Length */
if (mlBase>0xFFFF) { if (mlBase>0xFFFF) {
assert(seqStorePtr->longLengthID == 0); /* there can only be a single long length */ assert(seqStorePtr->longLengthType == ZSTD_llt_none); /* there can only be a single long length */
seqStorePtr->longLengthID = 2; seqStorePtr->longLengthType = ZSTD_llt_matchLength;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart); seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
} }
seqStorePtr->sequences[0].matchLength = (U16)mlBase; seqStorePtr->sequences[0].matchLength = (U16)mlBase;