diff options
Diffstat (limited to 'lib')
-rw-r--r-- | lib/lz4hc.c | 14 | ||||
-rw-r--r-- | lib/lz4opt.h | 61 |
2 files changed, 49 insertions, 26 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c index 388eb40..e6d496c 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -425,10 +425,7 @@ static int LZ4HC_compress_hashChain ( /* init */ *srcSizePtr = 0; - if (limit == limitedDestSize && maxOutputSize < 1) return 0; /* Impossible to store anything */ - if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size, too large (or negative) */ - - if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support limitations LZ4 decompressor */ + if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ /* Main Loop */ @@ -641,11 +638,12 @@ static int LZ4HC_compress_generic ( { lz4opt,8192, LZ4_OPT_NUM }, /* 12==LZ4HC_CLEVEL_MAX */ }; + if (limit == limitedDestSize && dstCapacity < 1) return 0; /* Impossible to store anything */ + if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0; /* Unsupported input size (too large or negative) */ + ctx->end += *srcSizePtr; if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT; /* note : convention is different from lz4frame, maybe something to review */ cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel); - if (limit == limitedDestSize) - cLevel = MIN(LZ4HC_CLEVEL_OPT_MIN-1, cLevel); /* no limitedDestSize variant for lz4opt */ assert(cLevel >= 0); assert(cLevel <= LZ4HC_CLEVEL_MAX); { cParams_t const cParam = clTable[cLevel]; @@ -655,8 +653,8 @@ static int LZ4HC_compress_generic ( cParam.nbSearches, limit); assert(cParam.strat == lz4opt); return LZ4HC_compress_optimal(ctx, - src, dst, *srcSizePtr, dstCapacity, limit, - cParam.nbSearches, cParam.targetLength, + src, dst, srcSizePtr, dstCapacity, + cParam.nbSearches, cParam.targetLength, limit, cLevel == LZ4HC_CLEVEL_MAX); /* ultra mode */ } } diff --git a/lib/lz4opt.h b/lib/lz4opt.h index 9917851..58068bf 100644 --- a/lib/lz4opt.h +++ b/lib/lz4opt.h @@ -97,11 +97,11 @@ static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx, const char* const source, char* dst, - int inputSize, + int* srcSizePtr, int dstCapacity, - limitedOutput_directive limit, int const nbSearches, size_t sufficient_len, + limitedOutput_directive limit, int const fullUpdate ) { @@ -110,14 +110,17 @@ static int LZ4HC_compress_optimal ( const BYTE* ip = (const BYTE*) source; const BYTE* anchor = ip; - const BYTE* const iend = ip + inputSize; + const BYTE* const iend = ip + *srcSizePtr; const BYTE* const mflimit = iend - MFLIMIT; const BYTE* const matchlimit = iend - LASTLITERALS; BYTE* op = (BYTE*) dst; - BYTE* const oend = op + dstCapacity; + BYTE* opSaved = (BYTE*) dst; + BYTE* oend = op + dstCapacity; /* init */ DEBUGLOG(5, "LZ4HC_compress_optimal"); + *srcSizePtr = 0; + if (limit == limitedDestSize) oend -= LASTLITERALS; /* Hack for support LZ4 format restriction */ if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1; /* Main Loop */ @@ -134,8 +137,9 @@ static int LZ4HC_compress_optimal ( /* good enough solution : immediate encoding */ int const firstML = firstMatch.len; const BYTE* const matchPos = ip - firstMatch.off; + opSaved = op; if ( LZ4HC_encodeSequence(&ip, &op, &anchor, firstML, matchPos, limit, oend) ) /* updates ip, op and anchor */ - return 0; /* error */ + goto _dest_overflow; continue; } @@ -304,26 +308,47 @@ encode: /* cur, last_match_pos, best_mlen, best_off must be set */ rPos += ml; assert(ml >= MINMATCH); assert((offset >= 1) && (offset <= MAX_DISTANCE)); + opSaved = op; if ( LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ip - offset, limit, oend) ) /* updates ip, op and anchor */ - return 0; /* error */ + goto _dest_overflow; } } } /* while (ip < mflimit) */ +_last_literals: /* Encode Last Literals */ - { int lastRun = (int)(iend - anchor); - if ( (limit) - && (((char*)op - dst) + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > (U32)dstCapacity)) - return 0; /* Check output limit */ - if (lastRun >= (int)RUN_MASK) { - *op++=(RUN_MASK<<ML_BITS); - lastRun-=RUN_MASK; - for (; lastRun > 254 ; lastRun-=255) *op++ = 255; - *op++ = (BYTE) lastRun; - } else *op++ = (BYTE)(lastRun<<ML_BITS); - memcpy(op, anchor, iend - anchor); - op += iend-anchor; + { size_t lastRunSize = (size_t)(iend - anchor); /* literals */ + size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255; + size_t const totalSize = 1 + litLength + lastRunSize; + if (limit == limitedDestSize) oend += LASTLITERALS; /* restore correct value */ + if (limit && (op + totalSize > oend)) { + if (limit == limitedOutput) return 0; /* Check output limit */ + /* adapt lastRunSize to fill 'dst' */ + lastRunSize = (size_t)(oend - op) - 1; + litLength = (lastRunSize + 255 - RUN_MASK) / 255; + lastRunSize -= litLength; + } + ip = anchor + lastRunSize; + + if (lastRunSize >= RUN_MASK) { + size_t accumulator = lastRunSize - RUN_MASK; + *op++ = (RUN_MASK << ML_BITS); + for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRunSize << ML_BITS); + } + memcpy(op, anchor, lastRunSize); + op += lastRunSize; } /* End */ + *srcSizePtr = (int) (((const char*)ip) - source); return (int) ((char*)op-dst); + +_dest_overflow: + if (limit == limitedDestSize) { + op = opSaved; /* restore correct out pointer */ + goto _last_literals; + } + return 0; } |