| /* ****************************************************************** |
| Huffman encoder, part of New Generation Entropy library |
| Copyright (C) 2013-2016, Yann Collet. |
| |
| BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above |
| copyright notice, this list of conditions and the following disclaimer |
| in the documentation and/or other materials provided with the |
| distribution. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| You can contact the author at : |
| - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy |
| - Public forum : https://groups.google.com/forum/#!forum/lz4c |
| ****************************************************************** */ |
| |
| /* ************************************************************** |
| * Compiler specifics |
| ****************************************************************/ |
| #if defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) |
| /* inline is defined */ |
| #elif defined(_MSC_VER) |
| # define inline __inline |
| #else |
| # define inline /* disable inline */ |
| #endif |
| |
| |
| #ifdef _MSC_VER /* Visual Studio */ |
| # define FORCE_INLINE static __forceinline |
| # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ |
| #else |
| # ifdef __GNUC__ |
| # define FORCE_INLINE static inline __attribute__((always_inline)) |
| # else |
| # define FORCE_INLINE static inline |
| # endif |
| #endif |
| |
| |
| /* ************************************************************** |
| * Includes |
| ****************************************************************/ |
| #include <string.h> /* memcpy, memset */ |
| #include <stdio.h> /* printf (debug) */ |
| #include "bitstream.h" |
| #define FSE_STATIC_LINKING_ONLY /* FSE_optimalTableLog_internal */ |
| #include "fse.h" /* header compression */ |
| #define HUF_STATIC_LINKING_ONLY |
| #include "huf.h" |
| |
| |
| /* ************************************************************** |
| * Error Management |
| ****************************************************************/ |
| #define HUF_STATIC_ASSERT(c) { enum { HUF_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */ |
| |
| |
| /* ************************************************************** |
| * Utils |
| ****************************************************************/ |
| unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue) |
| { |
| return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1); |
| } |
| |
| |
| /* ******************************************************* |
| * HUF : Huffman block compression |
| *********************************************************/ |
| struct HUF_CElt_s { |
| U16 val; |
| BYTE nbBits; |
| }; /* typedef'd to HUF_CElt within huf_static.h */ |
| |
| typedef struct nodeElt_s { |
| U32 count; |
| U16 parent; |
| BYTE byte; |
| BYTE nbBits; |
| } nodeElt; |
| |
| /*! HUF_writeCTable() : |
| `CTable` : huffman tree to save, using huf representation. |
| @return : size of saved CTable */ |
| size_t HUF_writeCTable (void* dst, size_t maxDstSize, |
| const HUF_CElt* CTable, U32 maxSymbolValue, U32 huffLog) |
| { |
| BYTE bitsToWeight[HUF_TABLELOG_MAX + 1]; |
| BYTE huffWeight[HUF_SYMBOLVALUE_MAX]; |
| BYTE* op = (BYTE*)dst; |
| U32 n; |
| |
| /* check conditions */ |
| if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(GENERIC); |
| |
| /* convert to weight */ |
| bitsToWeight[0] = 0; |
| for (n=1; n<huffLog+1; n++) |
| bitsToWeight[n] = (BYTE)(huffLog + 1 - n); |
| for (n=0; n<maxSymbolValue; n++) |
| huffWeight[n] = bitsToWeight[CTable[n].nbBits]; |
| |
| { size_t const size = FSE_compress(op+1, maxDstSize-1, huffWeight, maxSymbolValue); |
| if (FSE_isError(size)) return size; |
| if ((size>1) & (size < maxSymbolValue/2)) { /* FSE compressed */ |
| op[0] = (BYTE)size; |
| return size+1; |
| } } |
| |
| /* raw values */ |
| if (maxSymbolValue > (256-128)) return ERROR(GENERIC); /* should not happen */ |
| if (((maxSymbolValue+1)/2) + 1 > maxDstSize) return ERROR(dstSize_tooSmall); /* not enough space within dst buffer */ |
| op[0] = (BYTE)(128 /*special case*/ + (maxSymbolValue-1)); |
| huffWeight[maxSymbolValue] = 0; /* to be sure it doesn't cause issue in final combination */ |
| for (n=0; n<maxSymbolValue; n+=2) |
| op[(n/2)+1] = (BYTE)((huffWeight[n] << 4) + huffWeight[n+1]); |
| return ((maxSymbolValue+1)/2) + 1; |
| |
| } |
| |
| |
| size_t HUF_readCTable (HUF_CElt* CTable, U32 maxSymbolValue, const void* src, size_t srcSize) |
| { |
| BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1]; |
| U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1]; /* large enough for values from 0 to 16 */ |
| U32 tableLog = 0; |
| size_t readSize; |
| U32 nbSymbols = 0; |
| /*memset(huffWeight, 0, sizeof(huffWeight));*/ /* is not necessary, even though some analyzer complain ... */ |
| |
| /* get symbol weights */ |
| readSize = HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX+1, rankVal, &nbSymbols, &tableLog, src, srcSize); |
| if (HUF_isError(readSize)) return readSize; |
| |
| /* check result */ |
| if (tableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge); |
| if (nbSymbols > maxSymbolValue+1) return ERROR(maxSymbolValue_tooSmall); |
| |
| /* Prepare base value per rank */ |
| { U32 n, nextRankStart = 0; |
| for (n=1; n<=tableLog; n++) { |
| U32 current = nextRankStart; |
| nextRankStart += (rankVal[n] << (n-1)); |
| rankVal[n] = current; |
| } } |
| |
| /* fill nbBits */ |
| { U32 n; for (n=0; n<nbSymbols; n++) { |
| const U32 w = huffWeight[n]; |
| CTable[n].nbBits = (BYTE)(tableLog + 1 - w); |
| } } |
| |
| /* fill val */ |
| { U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0}; |
| U16 valPerRank[HUF_TABLELOG_MAX+1] = {0}; |
| { U32 n; for (n=0; n<nbSymbols; n++) nbPerRank[CTable[n].nbBits]++; } |
| /* determine stating value per rank */ |
| { U16 min = 0; |
| U32 n; for (n=HUF_TABLELOG_MAX; n>0; n--) { |
| valPerRank[n] = min; /* get starting value within each rank */ |
| min += nbPerRank[n]; |
| min >>= 1; |
| } } |
| /* assign value within rank, symbol order */ |
| { U32 n; for (n=0; n<=maxSymbolValue; n++) CTable[n].val = valPerRank[CTable[n].nbBits]++; } |
| } |
| |
| return readSize; |
| } |
| |
| |
| static U32 HUF_setMaxHeight(nodeElt* huffNode, U32 lastNonNull, U32 maxNbBits) |
| { |
| const U32 largestBits = huffNode[lastNonNull].nbBits; |
| if (largestBits <= maxNbBits) return largestBits; /* early exit : no elt > maxNbBits */ |
| |
| /* there are several too large elements (at least >= 2) */ |
| { int totalCost = 0; |
| const U32 baseCost = 1 << (largestBits - maxNbBits); |
| U32 n = lastNonNull; |
| |
| while (huffNode[n].nbBits > maxNbBits) { |
| totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits)); |
| huffNode[n].nbBits = (BYTE)maxNbBits; |
| n --; |
| } /* n stops at huffNode[n].nbBits <= maxNbBits */ |
| while (huffNode[n].nbBits == maxNbBits) n--; /* n end at index of smallest symbol using < maxNbBits */ |
| |
| /* renorm totalCost */ |
| totalCost >>= (largestBits - maxNbBits); /* note : totalCost is necessarily a multiple of baseCost */ |
| |
| /* repay normalized cost */ |
| { U32 const noSymbol = 0xF0F0F0F0; |
| U32 rankLast[HUF_TABLELOG_MAX+2]; |
| int pos; |
| |
| /* Get pos of last (smallest) symbol per rank */ |
| memset(rankLast, 0xF0, sizeof(rankLast)); |
| { U32 currentNbBits = maxNbBits; |
| for (pos=n ; pos >= 0; pos--) { |
| if (huffNode[pos].nbBits >= currentNbBits) continue; |
| currentNbBits = huffNode[pos].nbBits; /* < maxNbBits */ |
| rankLast[maxNbBits-currentNbBits] = pos; |
| } } |
| |
| while (totalCost > 0) { |
| U32 nBitsToDecrease = BIT_highbit32(totalCost) + 1; |
| for ( ; nBitsToDecrease > 1; nBitsToDecrease--) { |
| U32 highPos = rankLast[nBitsToDecrease]; |
| U32 lowPos = rankLast[nBitsToDecrease-1]; |
| if (highPos == noSymbol) continue; |
| if (lowPos == noSymbol) break; |
| { U32 const highTotal = huffNode[highPos].count; |
| U32 const lowTotal = 2 * huffNode[lowPos].count; |
| if (highTotal <= lowTotal) break; |
| } } |
| /* only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) */ |
| while ((nBitsToDecrease<=HUF_TABLELOG_MAX) && (rankLast[nBitsToDecrease] == noSymbol)) /* HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary */ |
| nBitsToDecrease ++; |
| totalCost -= 1 << (nBitsToDecrease-1); |
| if (rankLast[nBitsToDecrease-1] == noSymbol) |
| rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease]; /* this rank is no longer empty */ |
| huffNode[rankLast[nBitsToDecrease]].nbBits ++; |
| if (rankLast[nBitsToDecrease] == 0) /* special case, reached largest symbol */ |
| rankLast[nBitsToDecrease] = noSymbol; |
| else { |
| rankLast[nBitsToDecrease]--; |
| if (huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease) |
| rankLast[nBitsToDecrease] = noSymbol; /* this rank is now empty */ |
| } } /* while (totalCost > 0) */ |
| |
| while (totalCost < 0) { /* Sometimes, cost correction overshoot */ |
| if (rankLast[1] == noSymbol) { /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0 (using maxNbBits) */ |
| while (huffNode[n].nbBits == maxNbBits) n--; |
| huffNode[n+1].nbBits--; |
| rankLast[1] = n+1; |
| totalCost++; |
| continue; |
| } |
| huffNode[ rankLast[1] + 1 ].nbBits--; |
| rankLast[1]++; |
| totalCost ++; |
| } } } /* there are several too large elements (at least >= 2) */ |
| |
| return maxNbBits; |
| } |
| |
| |
| typedef struct { |
| U32 base; |
| U32 current; |
| } rankPos; |
| |
| static void HUF_sort(nodeElt* huffNode, const U32* count, U32 maxSymbolValue) |
| { |
| rankPos rank[32]; |
| U32 n; |
| |
| memset(rank, 0, sizeof(rank)); |
| for (n=0; n<=maxSymbolValue; n++) { |
| U32 r = BIT_highbit32(count[n] + 1); |
| rank[r].base ++; |
| } |
| for (n=30; n>0; n--) rank[n-1].base += rank[n].base; |
| for (n=0; n<32; n++) rank[n].current = rank[n].base; |
| for (n=0; n<=maxSymbolValue; n++) { |
| U32 const c = count[n]; |
| U32 const r = BIT_highbit32(c+1) + 1; |
| U32 pos = rank[r].current++; |
| while ((pos > rank[r].base) && (c > huffNode[pos-1].count)) huffNode[pos]=huffNode[pos-1], pos--; |
| huffNode[pos].count = c; |
| huffNode[pos].byte = (BYTE)n; |
| } |
| } |
| |
| |
| #define STARTNODE (HUF_SYMBOLVALUE_MAX+1) |
| size_t HUF_buildCTable (HUF_CElt* tree, const U32* count, U32 maxSymbolValue, U32 maxNbBits) |
| { |
| nodeElt huffNode0[2*HUF_SYMBOLVALUE_MAX+1 +1]; |
| nodeElt* huffNode = huffNode0 + 1; |
| U32 n, nonNullRank; |
| int lowS, lowN; |
| U16 nodeNb = STARTNODE; |
| U32 nodeRoot; |
| |
| /* safety checks */ |
| if (maxNbBits == 0) maxNbBits = HUF_TABLELOG_DEFAULT; |
| if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(GENERIC); |
| memset(huffNode0, 0, sizeof(huffNode0)); |
| |
| /* sort, decreasing order */ |
| HUF_sort(huffNode, count, maxSymbolValue); |
| |
| /* init for parents */ |
| nonNullRank = maxSymbolValue; |
| while(huffNode[nonNullRank].count == 0) nonNullRank--; |
| lowS = nonNullRank; nodeRoot = nodeNb + lowS - 1; lowN = nodeNb; |
| huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS-1].count; |
| huffNode[lowS].parent = huffNode[lowS-1].parent = nodeNb; |
| nodeNb++; lowS-=2; |
| for (n=nodeNb; n<=nodeRoot; n++) huffNode[n].count = (U32)(1U<<30); |
| huffNode0[0].count = (U32)(1U<<31); |
| |
| /* create parents */ |
| while (nodeNb <= nodeRoot) { |
| U32 n1 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++; |
| U32 n2 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++; |
| huffNode[nodeNb].count = huffNode[n1].count + huffNode[n2].count; |
| huffNode[n1].parent = huffNode[n2].parent = nodeNb; |
| nodeNb++; |
| } |
| |
| /* distribute weights (unlimited tree height) */ |
| huffNode[nodeRoot].nbBits = 0; |
| for (n=nodeRoot-1; n>=STARTNODE; n--) |
| huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1; |
| for (n=0; n<=nonNullRank; n++) |
| huffNode[n].nbBits = huffNode[ huffNode[n].parent ].nbBits + 1; |
| |
| /* enforce maxTableLog */ |
| maxNbBits = HUF_setMaxHeight(huffNode, nonNullRank, maxNbBits); |
| |
| /* fill result into tree (val, nbBits) */ |
| { U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0}; |
| U16 valPerRank[HUF_TABLELOG_MAX+1] = {0}; |
| if (maxNbBits > HUF_TABLELOG_MAX) return ERROR(GENERIC); /* check fit into table */ |
| for (n=0; n<=nonNullRank; n++) |
| nbPerRank[huffNode[n].nbBits]++; |
| /* determine stating value per rank */ |
| { U16 min = 0; |
| for (n=maxNbBits; n>0; n--) { |
| valPerRank[n] = min; /* get starting value within each rank */ |
| min += nbPerRank[n]; |
| min >>= 1; |
| } } |
| for (n=0; n<=maxSymbolValue; n++) |
| tree[huffNode[n].byte].nbBits = huffNode[n].nbBits; /* push nbBits per symbol, symbol order */ |
| for (n=0; n<=maxSymbolValue; n++) |
| tree[n].val = valPerRank[tree[n].nbBits]++; /* assign value within rank, symbol order */ |
| } |
| |
| return maxNbBits; |
| } |
| |
| static void HUF_encodeSymbol(BIT_CStream_t* bitCPtr, U32 symbol, const HUF_CElt* CTable) |
| { |
| BIT_addBitsFast(bitCPtr, CTable[symbol].val, CTable[symbol].nbBits); |
| } |
| |
| size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); } |
| |
| #define HUF_FLUSHBITS(s) (fast ? BIT_flushBitsFast(s) : BIT_flushBits(s)) |
| |
| #define HUF_FLUSHBITS_1(stream) \ |
| if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*2+7) HUF_FLUSHBITS(stream) |
| |
| #define HUF_FLUSHBITS_2(stream) \ |
| if (sizeof((stream)->bitContainer)*8 < HUF_TABLELOG_MAX*4+7) HUF_FLUSHBITS(stream) |
| |
| size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable) |
| { |
| const BYTE* ip = (const BYTE*) src; |
| BYTE* const ostart = (BYTE*)dst; |
| BYTE* const oend = ostart + dstSize; |
| BYTE* op = ostart; |
| size_t n; |
| const unsigned fast = (dstSize >= HUF_BLOCKBOUND(srcSize)); |
| BIT_CStream_t bitC; |
| |
| /* init */ |
| if (dstSize < 8) return 0; /* not enough space to compress */ |
| { size_t const errorCode = BIT_initCStream(&bitC, op, oend-op); |
| if (HUF_isError(errorCode)) return 0; } |
| |
| n = srcSize & ~3; /* join to mod 4 */ |
| switch (srcSize & 3) |
| { |
| case 3 : HUF_encodeSymbol(&bitC, ip[n+ 2], CTable); |
| HUF_FLUSHBITS_2(&bitC); |
| case 2 : HUF_encodeSymbol(&bitC, ip[n+ 1], CTable); |
| HUF_FLUSHBITS_1(&bitC); |
| case 1 : HUF_encodeSymbol(&bitC, ip[n+ 0], CTable); |
| HUF_FLUSHBITS(&bitC); |
| case 0 : |
| default: ; |
| } |
| |
| for (; n>0; n-=4) { /* note : n&3==0 at this stage */ |
| HUF_encodeSymbol(&bitC, ip[n- 1], CTable); |
| HUF_FLUSHBITS_1(&bitC); |
| HUF_encodeSymbol(&bitC, ip[n- 2], CTable); |
| HUF_FLUSHBITS_2(&bitC); |
| HUF_encodeSymbol(&bitC, ip[n- 3], CTable); |
| HUF_FLUSHBITS_1(&bitC); |
| HUF_encodeSymbol(&bitC, ip[n- 4], CTable); |
| HUF_FLUSHBITS(&bitC); |
| } |
| |
| return BIT_closeCStream(&bitC); |
| } |
| |
| |
| size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable) |
| { |
| size_t const segmentSize = (srcSize+3)/4; /* first 3 segments */ |
| const BYTE* ip = (const BYTE*) src; |
| const BYTE* const iend = ip + srcSize; |
| BYTE* const ostart = (BYTE*) dst; |
| BYTE* const oend = ostart + dstSize; |
| BYTE* op = ostart; |
| |
| if (dstSize < 6 + 1 + 1 + 1 + 8) return 0; /* minimum space to compress successfully */ |
| if (srcSize < 12) return 0; /* no saving possible : too small input */ |
| op += 6; /* jumpTable */ |
| |
| { size_t const cSize = HUF_compress1X_usingCTable(op, oend-op, ip, segmentSize, CTable); |
| if (HUF_isError(cSize)) return cSize; |
| if (cSize==0) return 0; |
| MEM_writeLE16(ostart, (U16)cSize); |
| op += cSize; |
| } |
| |
| ip += segmentSize; |
| { size_t const cSize = HUF_compress1X_usingCTable(op, oend-op, ip, segmentSize, CTable); |
| if (HUF_isError(cSize)) return cSize; |
| if (cSize==0) return 0; |
| MEM_writeLE16(ostart+2, (U16)cSize); |
| op += cSize; |
| } |
| |
| ip += segmentSize; |
| { size_t const cSize = HUF_compress1X_usingCTable(op, oend-op, ip, segmentSize, CTable); |
| if (HUF_isError(cSize)) return cSize; |
| if (cSize==0) return 0; |
| MEM_writeLE16(ostart+4, (U16)cSize); |
| op += cSize; |
| } |
| |
| ip += segmentSize; |
| { size_t const cSize = HUF_compress1X_usingCTable(op, oend-op, ip, iend-ip, CTable); |
| if (HUF_isError(cSize)) return cSize; |
| if (cSize==0) return 0; |
| op += cSize; |
| } |
| |
| return op-ostart; |
| } |
| |
| |
| static size_t HUF_compress_internal ( |
| void* dst, size_t dstSize, |
| const void* src, size_t srcSize, |
| unsigned maxSymbolValue, unsigned huffLog, |
| unsigned singleStream) |
| { |
| BYTE* const ostart = (BYTE*)dst; |
| BYTE* const oend = ostart + dstSize; |
| BYTE* op = ostart; |
| |
| U32 count[HUF_SYMBOLVALUE_MAX+1]; |
| HUF_CElt CTable[HUF_SYMBOLVALUE_MAX+1]; |
| |
| /* checks & inits */ |
| if (!srcSize) return 0; /* Uncompressed (note : 1 means rle, so first byte must be correct) */ |
| if (!dstSize) return 0; /* cannot fit within dst budget */ |
| if (srcSize > HUF_BLOCKSIZE_MAX) return ERROR(srcSize_wrong); /* current block size limit */ |
| if (huffLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge); |
| if (!maxSymbolValue) maxSymbolValue = HUF_SYMBOLVALUE_MAX; |
| if (!huffLog) huffLog = HUF_TABLELOG_DEFAULT; |
| |
| /* Scan input and build symbol stats */ |
| { size_t const largest = FSE_count (count, &maxSymbolValue, (const BYTE*)src, srcSize); |
| if (HUF_isError(largest)) return largest; |
| if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; } /* rle */ |
| if (largest <= (srcSize >> 7)+1) return 0; /* Fast heuristic : not compressible enough */ |
| } |
| |
| /* Build Huffman Tree */ |
| huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue); |
| { size_t const maxBits = HUF_buildCTable (CTable, count, maxSymbolValue, huffLog); |
| if (HUF_isError(maxBits)) return maxBits; |
| huffLog = (U32)maxBits; |
| } |
| |
| /* Write table description header */ |
| { size_t const hSize = HUF_writeCTable (op, dstSize, CTable, maxSymbolValue, huffLog); |
| if (HUF_isError(hSize)) return hSize; |
| if (hSize + 12 >= srcSize) return 0; /* not useful to try compression */ |
| op += hSize; |
| } |
| |
| /* Compress */ |
| { size_t const cSize = (singleStream) ? |
| HUF_compress1X_usingCTable(op, oend - op, src, srcSize, CTable) : /* single segment */ |
| HUF_compress4X_usingCTable(op, oend - op, src, srcSize, CTable); |
| if (HUF_isError(cSize)) return cSize; |
| if (cSize==0) return 0; /* uncompressible */ |
| op += cSize; |
| } |
| |
| /* check compressibility */ |
| if ((size_t)(op-ostart) >= srcSize-1) |
| return 0; |
| |
| return op-ostart; |
| } |
| |
| |
| size_t HUF_compress1X (void* dst, size_t dstSize, |
| const void* src, size_t srcSize, |
| unsigned maxSymbolValue, unsigned huffLog) |
| { |
| return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 1); |
| } |
| |
| size_t HUF_compress2 (void* dst, size_t dstSize, |
| const void* src, size_t srcSize, |
| unsigned maxSymbolValue, unsigned huffLog) |
| { |
| return HUF_compress_internal(dst, dstSize, src, srcSize, maxSymbolValue, huffLog, 0); |
| } |
| |
| |
| size_t HUF_compress (void* dst, size_t maxDstSize, const void* src, size_t srcSize) |
| { |
| return HUF_compress2(dst, maxDstSize, src, (U32)srcSize, 255, HUF_TABLELOG_DEFAULT); |
| } |