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change ZSTD_storeSeq() interface to accept matchLength

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instead of mlBase.

This removes the need to do `- MINMATCH` at every call site.

The new interface contract is checked with an `assert()`.
This commit is contained in:
Yann Collet
2021-12-23 12:03:33 -08:00
parent eebf24bd2a
commit b77fcac61f
8 changed files with 41 additions and 38 deletions
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lib/compress/zstd_compress_internal.h
+12 -9
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@@ -601,13 +601,13 @@ static void ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const ie
}
/*! ZSTD_storeSeq() :
* Store a sequence (litlen, litPtr, offCode and mlBase) into seqStore_t.
* Store a sequence (litlen, litPtr, offCode and matchLength) into seqStore_t.
* `offCode` : distance to match + ZSTD_REP_MOVE (values <= ZSTD_REP_MOVE are repCodes).
* `mlBase` : matchLength - MINMATCH
* @matchLength : must be >= MINMATCH
* Allowed to overread literals up to litLimit.
*/
HINT_INLINE UNUSED_ATTR
void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* literals, const BYTE* litLimit, U32 offCode, size_t mlBase)
void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* literals, const BYTE* litLimit, U32 offCode, size_t matchLength)
{
BYTE const* const litLimit_w = litLimit - WILDCOPY_OVERLENGTH;
BYTE const* const litEnd = literals + litLength;
@@ -616,7 +616,7 @@ void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* litera
if (g_start==NULL) g_start = (const BYTE*)literals; /* note : index only works for compression within a single segment */
{ U32 const pos = (U32)((const BYTE*)literals - g_start);
DEBUGLOG(6, "Cpos%7u :%3u literals, match%4u bytes at offCode%7u",
pos, (U32)litLength, (U32)mlBase+MINMATCH, (U32)offCode);
pos, (U32)litLength, (U32)matchLength, (U32)offCode);
}
#endif
assert((size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart) < seqStorePtr->maxNbSeq);
@@ -650,12 +650,15 @@ void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* litera
seqStorePtr->sequences[0].offset = offCode + 1;
/* match Length */
if (mlBase>0xFFFF) {
assert(seqStorePtr->longLengthType == ZSTD_llt_none); /* there can only be a single long length */
seqStorePtr->longLengthType = ZSTD_llt_matchLength;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
assert(matchLength >= MINMATCH);
{ size_t const mlBase = matchLength - MINMATCH;
if (mlBase>0xFFFF) {
assert(seqStorePtr->longLengthType == ZSTD_llt_none); /* there can only be a single long length */
seqStorePtr->longLengthType = ZSTD_llt_matchLength;
seqStorePtr->longLengthPos = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
}
seqStorePtr->sequences[0].matchLength = (U16)mlBase;
}
seqStorePtr->sequences[0].matchLength = (U16)mlBase;
seqStorePtr->sequences++;
}