ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

repfirst

Browse Source
This commit is contained in:
Yann Collet
2015-10-23 19:25:06 +01:00
parent 563c6ba8cc
commit ed0a781246
3 changed files with 42 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/zstdhc.c
+31 -13
View File
@@ -295,34 +295,52 @@ static size_t ZSTD_HC_compressBlock(ZSTD_HC_CCtx* ctx, void* dst, size_t maxDstS
{
seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src;
const BYTE* ip = istart + 1;
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
const BYTE* const ilimit = iend - 8;
size_t offset_2=4, offset_1=4;
size_t offset_2=REPCODE_STARTVALUE, offset_1=REPCODE_STARTVALUE;
const U32 maxSearches = 1 << ctx->compressionLevel;
/* init */
ZSTD_resetSeqStore(seqStorePtr);
if (((ip-ctx->base) - ctx->dictLimit) < REPCODE_STARTVALUE) ip += REPCODE_STARTVALUE;
/* Main Search Loop */
/* Match Loop */
while (ip < ilimit)
{
const BYTE* match;
size_t matchLength = ZSTD_HC_insertAndFindBestMatch(ctx, ip, ilimit, &match, maxSearches);
if (!matchLength) { ip++; continue; }
/* save match */
/* repcode */
if (MEM_read32(ip) == MEM_read32(ip - offset_2))
/* store sequence */
{
size_t matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend);
size_t litLength = ip-anchor;
size_t offset = ip-match;
if (litLength) offset_2 = offset_1;
if (offset == offset_2) offset = 0;
size_t offset = offset_2;
offset_2 = offset_1;
offset_1 = ip-match;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
ip += matchLength;
offset_1 = offset;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, 0, matchLength);
ip += matchLength+MINMATCH;
anchor = ip;
continue;
}
/* search */
{
const BYTE* match;
size_t matchLength = ZSTD_HC_insertAndFindBestMatch(ctx, ip, iend, &match, maxSearches);
if (!matchLength) { ip++; offset_2 = offset_1; continue; }
/* store sequence */
{
size_t litLength = ip-anchor;
size_t offset = ip-match;
if (offset == offset_2) offset = 0;
offset_2 = offset_1;
offset_1 = ip-match;
ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, matchLength-MINMATCH);
ip += matchLength;
anchor = ip;
}
}
}