From f007153e3f0c401d51d6ba5f6ecf27b223591ef2 Mon Sep 17 00:00:00 2001 From: remittor Date: Wed, 8 Mar 2017 11:11:15 +0300 Subject: [PATCH] lz4hc: Add LZ4_compressHC_destSize and LZ4_compress_HC_continue_destSize --- lib/lz4hc.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------- lib/lz4hc.h | 2 ++ 2 files changed, 66 insertions(+), 10 deletions(-) diff --git a/lib/lz4hc.c b/lib/lz4hc.c index d3cc831..abea72e 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -248,7 +248,11 @@ FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( } -typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive; +typedef enum { + noLimit = 0, + limitedOutput = 1, + limitedDestSize = 2, +} limitedOutput_directive; #define LZ4HC_DEBUG 0 #if LZ4HC_DEBUG @@ -318,18 +322,21 @@ static int LZ4HC_compress_hashChain ( LZ4HC_CCtx_internal* const ctx, const char* const source, char* const dest, - int const inputSize, + int* srcSizePtr, int const maxOutputSize, unsigned maxNbAttempts, limitedOutput_directive limit ) { + const int inputSize = *srcSizePtr; + const BYTE* ip = (const BYTE*) source; const BYTE* anchor = ip; const BYTE* const iend = ip + inputSize; const BYTE* const mflimit = iend - MFLIMIT; const BYTE* const matchlimit = (iend - LASTLITERALS); + BYTE* optr = (BYTE*) dest; BYTE* op = (BYTE*) dest; BYTE* const oend = op + maxOutputSize; @@ -343,7 +350,12 @@ static int LZ4HC_compress_hashChain ( const BYTE* ref0; /* init */ + *srcSizePtr = 0; + if (limit && 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) */ + ctx->end += inputSize; + if (inputSize < LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ ip++; @@ -363,7 +375,8 @@ _Search2: else ml2 = ml; if (ml2 == ml) { /* No better match */ - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + optr = op; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; continue; } @@ -412,9 +425,11 @@ _Search3: /* ip & ref are known; Now for ml */ if (start2 < ip+ml) ml = (int)(start2 - ip); /* Now, encode 2 sequences */ - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + optr = op; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; ip = start2; - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) return 0; + optr = op; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml2, ref2, limit, oend)) goto _dest_overflow; continue; } @@ -432,7 +447,8 @@ _Search3: } } - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + optr = op; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; ip = start3; ref = ref3; ml = ml3; @@ -468,7 +484,8 @@ _Search3: ml = (int)(start2 - ip); } } - if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) return 0; + optr = op; + if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml, ref, limit, oend)) goto _dest_overflow; ip = start2; ref = ref2; @@ -481,12 +498,21 @@ _Search3: goto _Search3; } +_last_literals: /* Encode Last Literals */ { size_t lastRunSize, litLength, totalSize; lastRunSize = (size_t)(iend - anchor); /* literals */ litLength = (lastRunSize + 255 - RUN_MASK) / 255; totalSize = 1 + litLength + lastRunSize; - if ((limit == limitedOutput) && (op + totalSize > oend)) return 0; /* Check output limit */ + 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); @@ -500,7 +526,15 @@ _Search3: } /* End */ + *srcSizePtr = (int) (((const char*)ip) - source); return (int) (((char*)op)-dest); + +_dest_overflow: + if (limit == limitedDestSize) { + op = optr; /* restore correct out pointer */ + goto _last_literals; + } + return 0; } static int LZ4HC_getSearchNum(int compressionLevel) @@ -522,16 +556,17 @@ static int LZ4HC_compress_generic ( limitedOutput_directive limit ) { + int srcSize = inputSize; if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT; if (compressionLevel > 9) { switch (compressionLevel) { - case 10: return LZ4HC_compress_hashChain(ctx, source, dest, inputSize, maxOutputSize, 1 << (16-1), limit); + case 10: return LZ4HC_compress_hashChain(ctx, source, dest, &srcSize, maxOutputSize, 1 << (16-1), limit); case 11: ctx->searchNum = LZ4HC_getSearchNum(compressionLevel); return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, 128, 0); default: case 12: ctx->searchNum = LZ4HC_getSearchNum(compressionLevel); return LZ4HC_compress_optimal(ctx, source, dest, inputSize, maxOutputSize, limit, LZ4_OPT_NUM, 1); } } - return LZ4HC_compress_hashChain(ctx, source, dest, inputSize, maxOutputSize, 1 << (compressionLevel-1), limit); + return LZ4HC_compress_hashChain(ctx, source, dest, &srcSize, maxOutputSize, 1 << (compressionLevel-1), limit); } @@ -657,6 +692,17 @@ int LZ4_compress_HC_continue (LZ4_streamHC_t* LZ4_streamHCPtr, const char* sourc return LZ4_compressHC_continue_generic (LZ4_streamHCPtr, source, dest, inputSize, maxOutputSize, noLimit); } +int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* source, char* dest, int* sourceSizePtr, int targetDestSize) +{ + LZ4HC_CCtx_internal* ctxPtr = &LZ4_streamHCPtr->internal_donotuse; + unsigned maxNbAttempts = 1 << (ctxPtr->compressionLevel - 1); + + /* destSize: always auto-init */ + LZ4HC_init(ctxPtr, (const BYTE*) source); + + return LZ4HC_compress_hashChain(ctxPtr, source, dest, sourceSizePtr, targetDestSize, maxNbAttempts, limitedDestSize); +} + /* dictionary saving */ @@ -735,3 +781,11 @@ char* LZ4_slideInputBufferHC(void* LZ4HC_Data) int const dictSize = LZ4_saveDictHC((LZ4_streamHC_t*)LZ4HC_Data, (char*)(hc4->inputBuffer), 64 KB); return (char*)(hc4->inputBuffer + dictSize); } + +int LZ4_compressHC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int compressionLevel) +{ + LZ4HC_CCtx_internal * const ctx = &((LZ4_streamHC_t*)LZ4HC_Data)->internal_donotuse; + unsigned maxNbAttempts = 1 << (compressionLevel - 1); + LZ4HC_init(ctx, (const BYTE*) source); + return LZ4HC_compress_hashChain(ctx, source, dest, sourceSizePtr, targetDestSize, maxNbAttempts, limitedDestSize); +} diff --git a/lib/lz4hc.h b/lib/lz4hc.h index 1036fd0..13112f9 100644 --- a/lib/lz4hc.h +++ b/lib/lz4hc.h @@ -99,6 +99,7 @@ LZ4LIB_API void LZ4_resetStreamHC (LZ4_streamHC_t* streamHCPtr, int compressionL LZ4LIB_API int LZ4_loadDictHC (LZ4_streamHC_t* streamHCPtr, const char* dictionary, int dictSize); LZ4LIB_API int LZ4_compress_HC_continue (LZ4_streamHC_t* streamHCPtr, const char* src, char* dst, int srcSize, int maxDstSize); +LZ4LIB_API int LZ4_compress_HC_continue_destSize (LZ4_streamHC_t* LZ4_streamHCPtr, const char* src, char* dst, int* srcSizePtr, int maxDstSize); LZ4LIB_API int LZ4_saveDictHC (LZ4_streamHC_t* streamHCPtr, char* safeBuffer, int maxDictSize); @@ -219,6 +220,7 @@ LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_con LZ4_DEPRECATED("use LZ4_compress_HC_continue() instead") int LZ4_compressHC2_limitedOutput_continue (void* LZ4HC_Data, const char* source, char* dest, int inputSize, int maxOutputSize, int compressionLevel); LZ4_DEPRECATED("use LZ4_createStreamHC() instead") int LZ4_sizeofStreamStateHC(void); LZ4_DEPRECATED("use LZ4_resetStreamHC() instead") int LZ4_resetStreamStateHC(void* state, char* inputBuffer); +LZ4_DEPRECATED("use LZ4_compress_HC_continue_destSize() instead") int LZ4_compressHC_destSize(void* LZ4HC_Data, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int compressionLevel); #if defined (__cplusplus) -- 2.7.4