diff options
Diffstat (limited to 'lib/compress/zstd_compress_internal.h')
| -rw-r--r-- | lib/compress/zstd_compress_internal.h | 111 |
1 files changed, 72 insertions, 39 deletions
diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h index 7360ee8e..c406e794 100644 --- a/lib/compress/zstd_compress_internal.h +++ b/lib/compress/zstd_compress_internal.h @@ -129,7 +129,7 @@ size_t ZSTD_buildBlockEntropyStats(seqStore_t* seqStorePtr, *********************************/ typedef struct { - U32 off; /* Offset code (offset + ZSTD_REP_MOVE) for the match */ + U32 off; /* Offset sumtype code for the match, using ZSTD_storeSeq() format */ U32 len; /* Raw length of match */ } ZSTD_match_t; @@ -497,31 +497,6 @@ MEM_STATIC U32 ZSTD_MLcode(U32 mlBase) return (mlBase > 127) ? ZSTD_highbit32(mlBase) + ML_deltaCode : ML_Code[mlBase]; } -typedef struct repcodes_s { - U32 rep[3]; -} repcodes_t; - -MEM_STATIC 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 */ - ZSTD_memcpy(&newReps, rep, sizeof(newReps)); - } - } - return newReps; -} - /* ZSTD_cParam_withinBounds: * @return 1 if value is within cParam bounds, * 0 otherwise */ @@ -590,7 +565,9 @@ MEM_STATIC int ZSTD_literalsCompressionIsDisabled(const ZSTD_CCtx_params* cctxPa * Only called when the sequence ends past ilimit_w, so it only needs to be optimized for single * large copies. */ -static void ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const iend, BYTE const* ilimit_w) { +static void +ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const iend, BYTE const* ilimit_w) +{ assert(iend > ilimit_w); if (ip <= ilimit_w) { ZSTD_wildcopy(op, ip, ilimit_w - ip, ZSTD_no_overlap); @@ -600,14 +577,30 @@ static void ZSTD_safecopyLiterals(BYTE* op, BYTE const* ip, BYTE const* const ie while (ip < iend) *op++ = *ip++; } +#define ZSTD_REP_MOVE (ZSTD_REP_NUM-1) +#define STORE_REPCODE_1 STORE_REPCODE(1) +#define STORE_REPCODE_2 STORE_REPCODE(2) +#define STORE_REPCODE_3 STORE_REPCODE(3) +#define STORE_REPCODE(r) (assert((r)>=1), assert((r)<=3), (r)-1) +#define STORE_OFFSET(o) (assert((o)>0), o + ZSTD_REP_MOVE) +#define STORED_IS_OFFSET(o) ((o) > ZSTD_REP_MOVE) +#define STORED_IS_REPCODE(o) ((o) <= ZSTD_REP_MOVE) +#define STORED_OFFSET(o) (assert(STORED_IS_OFFSET(o)), (o)-ZSTD_REP_MOVE) +#define STORED_REPCODE(o) (assert(STORED_IS_REPCODE(o)), (o)+1) /* returns ID 1,2,3 */ +#define STORED_TO_OFFBASE(o) ((o)+1) +#define OFFBASE_TO_STORED(o) ((o)-1) + /*! ZSTD_storeSeq() : - * Store a sequence (litlen, litPtr, offCode and mlBase) into seqStore_t. - * `offCode` : distance to match + ZSTD_REP_MOVE (values <= ZSTD_REP_MOVE are repCodes). - * `mlBase` : matchLength - MINMATCH + * Store a sequence (litlen, litPtr, offCode and matchLength) into seqStore_t. + * @offBase_minus1 : Users should use employ macros STORE_REPCODE_X and STORE_OFFSET(). + * @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) +HINT_INLINE UNUSED_ATTR void +ZSTD_storeSeq(seqStore_t* seqStorePtr, + size_t litLength, const BYTE* literals, const BYTE* litLimit, + U32 offBase_minus1, + size_t matchLength) { BYTE const* const litLimit_w = litLimit - WILDCOPY_OVERLENGTH; BYTE const* const litEnd = literals + litLength; @@ -616,7 +609,7 @@ 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)offBase_minus1); } #endif assert((size_t)(seqStorePtr->sequences - seqStorePtr->sequencesStart) < seqStorePtr->maxNbSeq); @@ -647,19 +640,59 @@ void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const BYTE* litera seqStorePtr->sequences[0].litLength = (U16)litLength; /* match offset */ - seqStorePtr->sequences[0].offset = offCode + 1; + seqStorePtr->sequences[0].offBase = STORED_TO_OFFBASE(offBase_minus1); /* 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].mlBase = (U16)mlBase; } - seqStorePtr->sequences[0].matchLength = (U16)mlBase; seqStorePtr->sequences++; } +/* ZSTD_updateRep() : + * updates in-place @rep (array of repeat offsets) + * @offBase_minus1 : sum-type, with same numeric representation as ZSTD_storeSeq() + */ +MEM_STATIC void +ZSTD_updateRep(U32 rep[ZSTD_REP_NUM], U32 const offBase_minus1, U32 const ll0) +{ + if (STORED_IS_OFFSET(offBase_minus1)) { /* full offset */ + rep[2] = rep[1]; + rep[1] = rep[0]; + rep[0] = STORED_OFFSET(offBase_minus1); + } else { /* repcode */ + U32 const repCode = STORED_REPCODE(offBase_minus1) - 1 + ll0; + if (repCode > 0) { /* note : if repCode==0, no change */ + U32 const currentOffset = (repCode==ZSTD_REP_NUM) ? (rep[0] - 1) : rep[repCode]; + rep[2] = (repCode >= 2) ? rep[1] : rep[2]; + rep[1] = rep[0]; + rep[0] = currentOffset; + } else { /* repCode == 0 */ + /* nothing to do */ + } + } +} + +typedef struct repcodes_s { + U32 rep[3]; +} repcodes_t; + +MEM_STATIC repcodes_t +ZSTD_newRep(U32 const rep[ZSTD_REP_NUM], U32 const offBase_minus1, U32 const ll0) +{ + repcodes_t newReps; + ZSTD_memcpy(&newReps, rep, sizeof(newReps)); + ZSTD_updateRep(newReps.rep, offBase_minus1, ll0); + return newReps; +} + /*-************************************* * Match length counter |