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2aa14b1ab2
Updates the kernel's zstd library to v1.5.2, the latest zstd release. The upstream tag it is updated to is `v1.5.2-kernel`, which contains several cherry-picked commits on top of the v1.5.2 release which are required for the kernel update. I will create this tag once the PR is ready to merge, until then reference the temporary upstream branch `v1.5.2-kernel-cherrypicks`. I plan to submit this patch as part of the v6.2 merge window. I've done basic build testing & testing on x86-64, i386, and aarch64. I'm merging these patches into my `zstd-next` branch, which is pulled into `linux-next` for further testing. I've benchmarked BtrFS with zstd compression on a x86-64 machine, and saw these results. Decompression speed is a small win across the board. The lower compression levels 1-4 see both compression speed and compression ratio wins. The higher compression levels see a small compression speed loss and about neutral ratio. I expect the lower compression levels to be used much more heavily than the high compression levels, so this should be a net win. Level CTime DTime Ratio 1 -2.95% -1.1% -0.7% 3 -3.5% -1.2% -0.5% 5 +3.7% -1.0% +0.0% 7 +3.2% -0.9% +0.0% 9 -4.3% -0.8% +0.1% Signed-off-by: Nick Terrell <terrelln@fb.com>
1335 lines
54 KiB
C
1335 lines
54 KiB
C
/* ******************************************************************
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* Huffman encoder, part of New Generation Entropy library
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* Copyright (c) Yann Collet, Facebook, Inc.
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*
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* You can contact the author at :
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* - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
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* - Public forum : https://groups.google.com/forum/#!forum/lz4c
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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****************************************************************** */
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/* **************************************************************
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* Compiler specifics
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****************************************************************/
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/* **************************************************************
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* Includes
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****************************************************************/
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#include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memset */
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#include "../common/compiler.h"
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#include "../common/bitstream.h"
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#include "hist.h"
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#define FSE_STATIC_LINKING_ONLY /* FSE_optimalTableLog_internal */
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#include "../common/fse.h" /* header compression */
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#define HUF_STATIC_LINKING_ONLY
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#include "../common/huf.h"
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#include "../common/error_private.h"
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/* **************************************************************
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* Error Management
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****************************************************************/
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#define HUF_isError ERR_isError
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#define HUF_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c) /* use only *after* variable declarations */
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/* **************************************************************
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* Utils
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****************************************************************/
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unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue)
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{
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return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1);
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}
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/* *******************************************************
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* HUF : Huffman block compression
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*********************************************************/
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#define HUF_WORKSPACE_MAX_ALIGNMENT 8
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static void* HUF_alignUpWorkspace(void* workspace, size_t* workspaceSizePtr, size_t align)
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{
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size_t const mask = align - 1;
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size_t const rem = (size_t)workspace & mask;
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size_t const add = (align - rem) & mask;
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BYTE* const aligned = (BYTE*)workspace + add;
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assert((align & (align - 1)) == 0); /* pow 2 */
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assert(align <= HUF_WORKSPACE_MAX_ALIGNMENT);
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if (*workspaceSizePtr >= add) {
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assert(add < align);
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assert(((size_t)aligned & mask) == 0);
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*workspaceSizePtr -= add;
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return aligned;
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} else {
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*workspaceSizePtr = 0;
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return NULL;
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}
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}
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/* HUF_compressWeights() :
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* Same as FSE_compress(), but dedicated to huff0's weights compression.
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* The use case needs much less stack memory.
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* Note : all elements within weightTable are supposed to be <= HUF_TABLELOG_MAX.
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*/
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#define MAX_FSE_TABLELOG_FOR_HUFF_HEADER 6
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typedef struct {
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FSE_CTable CTable[FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX)];
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U32 scratchBuffer[FSE_BUILD_CTABLE_WORKSPACE_SIZE_U32(HUF_TABLELOG_MAX, MAX_FSE_TABLELOG_FOR_HUFF_HEADER)];
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unsigned count[HUF_TABLELOG_MAX+1];
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S16 norm[HUF_TABLELOG_MAX+1];
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} HUF_CompressWeightsWksp;
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static size_t HUF_compressWeights(void* dst, size_t dstSize, const void* weightTable, size_t wtSize, void* workspace, size_t workspaceSize)
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{
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BYTE* const ostart = (BYTE*) dst;
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BYTE* op = ostart;
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BYTE* const oend = ostart + dstSize;
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unsigned maxSymbolValue = HUF_TABLELOG_MAX;
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U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;
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HUF_CompressWeightsWksp* wksp = (HUF_CompressWeightsWksp*)HUF_alignUpWorkspace(workspace, &workspaceSize, ZSTD_ALIGNOF(U32));
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if (workspaceSize < sizeof(HUF_CompressWeightsWksp)) return ERROR(GENERIC);
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/* init conditions */
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if (wtSize <= 1) return 0; /* Not compressible */
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/* Scan input and build symbol stats */
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{ unsigned const maxCount = HIST_count_simple(wksp->count, &maxSymbolValue, weightTable, wtSize); /* never fails */
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if (maxCount == wtSize) return 1; /* only a single symbol in src : rle */
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if (maxCount == 1) return 0; /* each symbol present maximum once => not compressible */
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}
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tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
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CHECK_F( FSE_normalizeCount(wksp->norm, tableLog, wksp->count, wtSize, maxSymbolValue, /* useLowProbCount */ 0) );
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/* Write table description header */
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{ CHECK_V_F(hSize, FSE_writeNCount(op, (size_t)(oend-op), wksp->norm, maxSymbolValue, tableLog) );
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op += hSize;
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}
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/* Compress */
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CHECK_F( FSE_buildCTable_wksp(wksp->CTable, wksp->norm, maxSymbolValue, tableLog, wksp->scratchBuffer, sizeof(wksp->scratchBuffer)) );
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{ CHECK_V_F(cSize, FSE_compress_usingCTable(op, (size_t)(oend - op), weightTable, wtSize, wksp->CTable) );
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if (cSize == 0) return 0; /* not enough space for compressed data */
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op += cSize;
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}
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return (size_t)(op-ostart);
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}
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static size_t HUF_getNbBits(HUF_CElt elt)
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{
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return elt & 0xFF;
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}
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static size_t HUF_getNbBitsFast(HUF_CElt elt)
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{
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return elt;
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}
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static size_t HUF_getValue(HUF_CElt elt)
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{
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return elt & ~0xFF;
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}
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static size_t HUF_getValueFast(HUF_CElt elt)
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{
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return elt;
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}
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static void HUF_setNbBits(HUF_CElt* elt, size_t nbBits)
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{
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assert(nbBits <= HUF_TABLELOG_ABSOLUTEMAX);
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*elt = nbBits;
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}
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static void HUF_setValue(HUF_CElt* elt, size_t value)
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{
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size_t const nbBits = HUF_getNbBits(*elt);
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if (nbBits > 0) {
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assert((value >> nbBits) == 0);
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*elt |= value << (sizeof(HUF_CElt) * 8 - nbBits);
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}
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}
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typedef struct {
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HUF_CompressWeightsWksp wksp;
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BYTE bitsToWeight[HUF_TABLELOG_MAX + 1]; /* precomputed conversion table */
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BYTE huffWeight[HUF_SYMBOLVALUE_MAX];
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} HUF_WriteCTableWksp;
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size_t HUF_writeCTable_wksp(void* dst, size_t maxDstSize,
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const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog,
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void* workspace, size_t workspaceSize)
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{
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HUF_CElt const* const ct = CTable + 1;
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BYTE* op = (BYTE*)dst;
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U32 n;
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HUF_WriteCTableWksp* wksp = (HUF_WriteCTableWksp*)HUF_alignUpWorkspace(workspace, &workspaceSize, ZSTD_ALIGNOF(U32));
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/* check conditions */
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if (workspaceSize < sizeof(HUF_WriteCTableWksp)) return ERROR(GENERIC);
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if (maxSymbolValue > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
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/* convert to weight */
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wksp->bitsToWeight[0] = 0;
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for (n=1; n<huffLog+1; n++)
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wksp->bitsToWeight[n] = (BYTE)(huffLog + 1 - n);
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for (n=0; n<maxSymbolValue; n++)
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wksp->huffWeight[n] = wksp->bitsToWeight[HUF_getNbBits(ct[n])];
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/* attempt weights compression by FSE */
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if (maxDstSize < 1) return ERROR(dstSize_tooSmall);
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{ CHECK_V_F(hSize, HUF_compressWeights(op+1, maxDstSize-1, wksp->huffWeight, maxSymbolValue, &wksp->wksp, sizeof(wksp->wksp)) );
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if ((hSize>1) & (hSize < maxSymbolValue/2)) { /* FSE compressed */
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op[0] = (BYTE)hSize;
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return hSize+1;
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} }
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/* write raw values as 4-bits (max : 15) */
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if (maxSymbolValue > (256-128)) return ERROR(GENERIC); /* should not happen : likely means source cannot be compressed */
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if (((maxSymbolValue+1)/2) + 1 > maxDstSize) return ERROR(dstSize_tooSmall); /* not enough space within dst buffer */
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op[0] = (BYTE)(128 /*special case*/ + (maxSymbolValue-1));
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wksp->huffWeight[maxSymbolValue] = 0; /* to be sure it doesn't cause msan issue in final combination */
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for (n=0; n<maxSymbolValue; n+=2)
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op[(n/2)+1] = (BYTE)((wksp->huffWeight[n] << 4) + wksp->huffWeight[n+1]);
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return ((maxSymbolValue+1)/2) + 1;
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}
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/*! HUF_writeCTable() :
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`CTable` : Huffman tree to save, using huf representation.
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@return : size of saved CTable */
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size_t HUF_writeCTable (void* dst, size_t maxDstSize,
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const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog)
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{
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HUF_WriteCTableWksp wksp;
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return HUF_writeCTable_wksp(dst, maxDstSize, CTable, maxSymbolValue, huffLog, &wksp, sizeof(wksp));
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}
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size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned* hasZeroWeights)
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{
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BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1]; /* init not required, even though some static analyzer may complain */
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U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1]; /* large enough for values from 0 to 16 */
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U32 tableLog = 0;
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U32 nbSymbols = 0;
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HUF_CElt* const ct = CTable + 1;
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/* get symbol weights */
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CHECK_V_F(readSize, HUF_readStats(huffWeight, HUF_SYMBOLVALUE_MAX+1, rankVal, &nbSymbols, &tableLog, src, srcSize));
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*hasZeroWeights = (rankVal[0] > 0);
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/* check result */
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if (tableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
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if (nbSymbols > *maxSymbolValuePtr+1) return ERROR(maxSymbolValue_tooSmall);
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CTable[0] = tableLog;
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/* Prepare base value per rank */
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{ U32 n, nextRankStart = 0;
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for (n=1; n<=tableLog; n++) {
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U32 curr = nextRankStart;
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nextRankStart += (rankVal[n] << (n-1));
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rankVal[n] = curr;
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} }
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/* fill nbBits */
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{ U32 n; for (n=0; n<nbSymbols; n++) {
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const U32 w = huffWeight[n];
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HUF_setNbBits(ct + n, (BYTE)(tableLog + 1 - w) & -(w != 0));
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} }
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/* fill val */
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{ U16 nbPerRank[HUF_TABLELOG_MAX+2] = {0}; /* support w=0=>n=tableLog+1 */
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U16 valPerRank[HUF_TABLELOG_MAX+2] = {0};
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{ U32 n; for (n=0; n<nbSymbols; n++) nbPerRank[HUF_getNbBits(ct[n])]++; }
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/* determine stating value per rank */
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valPerRank[tableLog+1] = 0; /* for w==0 */
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{ U16 min = 0;
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U32 n; for (n=tableLog; n>0; n--) { /* start at n=tablelog <-> w=1 */
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valPerRank[n] = min; /* get starting value within each rank */
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min += nbPerRank[n];
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min >>= 1;
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} }
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/* assign value within rank, symbol order */
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{ U32 n; for (n=0; n<nbSymbols; n++) HUF_setValue(ct + n, valPerRank[HUF_getNbBits(ct[n])]++); }
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}
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*maxSymbolValuePtr = nbSymbols - 1;
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return readSize;
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}
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U32 HUF_getNbBitsFromCTable(HUF_CElt const* CTable, U32 symbolValue)
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{
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const HUF_CElt* ct = CTable + 1;
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assert(symbolValue <= HUF_SYMBOLVALUE_MAX);
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return (U32)HUF_getNbBits(ct[symbolValue]);
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}
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typedef struct nodeElt_s {
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U32 count;
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U16 parent;
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BYTE byte;
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BYTE nbBits;
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} nodeElt;
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/*
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* HUF_setMaxHeight():
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* Enforces maxNbBits on the Huffman tree described in huffNode.
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*
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* It sets all nodes with nbBits > maxNbBits to be maxNbBits. Then it adjusts
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* the tree to so that it is a valid canonical Huffman tree.
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*
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* @pre The sum of the ranks of each symbol == 2^largestBits,
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* where largestBits == huffNode[lastNonNull].nbBits.
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* @post The sum of the ranks of each symbol == 2^largestBits,
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* where largestBits is the return value <= maxNbBits.
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*
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* @param huffNode The Huffman tree modified in place to enforce maxNbBits.
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* @param lastNonNull The symbol with the lowest count in the Huffman tree.
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* @param maxNbBits The maximum allowed number of bits, which the Huffman tree
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* may not respect. After this function the Huffman tree will
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* respect maxNbBits.
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* @return The maximum number of bits of the Huffman tree after adjustment,
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* necessarily no more than maxNbBits.
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*/
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static U32 HUF_setMaxHeight(nodeElt* huffNode, U32 lastNonNull, U32 maxNbBits)
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{
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const U32 largestBits = huffNode[lastNonNull].nbBits;
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/* early exit : no elt > maxNbBits, so the tree is already valid. */
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if (largestBits <= maxNbBits) return largestBits;
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/* there are several too large elements (at least >= 2) */
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{ int totalCost = 0;
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const U32 baseCost = 1 << (largestBits - maxNbBits);
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int n = (int)lastNonNull;
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/* Adjust any ranks > maxNbBits to maxNbBits.
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* Compute totalCost, which is how far the sum of the ranks is
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* we are over 2^largestBits after adjust the offending ranks.
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*/
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while (huffNode[n].nbBits > maxNbBits) {
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totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits));
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huffNode[n].nbBits = (BYTE)maxNbBits;
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n--;
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}
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/* n stops at huffNode[n].nbBits <= maxNbBits */
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assert(huffNode[n].nbBits <= maxNbBits);
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/* n end at index of smallest symbol using < maxNbBits */
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while (huffNode[n].nbBits == maxNbBits) --n;
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/* renorm totalCost from 2^largestBits to 2^maxNbBits
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* note : totalCost is necessarily a multiple of baseCost */
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assert((totalCost & (baseCost - 1)) == 0);
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totalCost >>= (largestBits - maxNbBits);
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assert(totalCost > 0);
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/* repay normalized cost */
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{ U32 const noSymbol = 0xF0F0F0F0;
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U32 rankLast[HUF_TABLELOG_MAX+2];
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/* Get pos of last (smallest = lowest cum. count) symbol per rank */
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ZSTD_memset(rankLast, 0xF0, sizeof(rankLast));
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{ U32 currentNbBits = maxNbBits;
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int pos;
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for (pos=n ; pos >= 0; pos--) {
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if (huffNode[pos].nbBits >= currentNbBits) continue;
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currentNbBits = huffNode[pos].nbBits; /* < maxNbBits */
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rankLast[maxNbBits-currentNbBits] = (U32)pos;
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} }
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while (totalCost > 0) {
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/* Try to reduce the next power of 2 above totalCost because we
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* gain back half the rank.
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*/
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U32 nBitsToDecrease = BIT_highbit32((U32)totalCost) + 1;
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for ( ; nBitsToDecrease > 1; nBitsToDecrease--) {
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U32 const highPos = rankLast[nBitsToDecrease];
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U32 const lowPos = rankLast[nBitsToDecrease-1];
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if (highPos == noSymbol) continue;
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/* Decrease highPos if no symbols of lowPos or if it is
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* not cheaper to remove 2 lowPos than highPos.
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*/
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if (lowPos == noSymbol) break;
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{ U32 const highTotal = huffNode[highPos].count;
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U32 const lowTotal = 2 * huffNode[lowPos].count;
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if (highTotal <= lowTotal) break;
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} }
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/* only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) */
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assert(rankLast[nBitsToDecrease] != noSymbol || nBitsToDecrease == 1);
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/* HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary */
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while ((nBitsToDecrease<=HUF_TABLELOG_MAX) && (rankLast[nBitsToDecrease] == noSymbol))
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nBitsToDecrease++;
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assert(rankLast[nBitsToDecrease] != noSymbol);
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/* Increase the number of bits to gain back half the rank cost. */
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totalCost -= 1 << (nBitsToDecrease-1);
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huffNode[rankLast[nBitsToDecrease]].nbBits++;
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/* Fix up the new rank.
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* If the new rank was empty, this symbol is now its smallest.
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* Otherwise, this symbol will be the largest in the new rank so no adjustment.
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*/
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if (rankLast[nBitsToDecrease-1] == noSymbol)
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rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease];
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/* Fix up the old rank.
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* If the symbol was at position 0, meaning it was the highest weight symbol in the tree,
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* it must be the only symbol in its rank, so the old rank now has no symbols.
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* Otherwise, since the Huffman nodes are sorted by count, the previous position is now
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* the smallest node in the rank. If the previous position belongs to a different rank,
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* then the rank is now empty.
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*/
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if (rankLast[nBitsToDecrease] == 0) /* special case, reached largest symbol */
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rankLast[nBitsToDecrease] = noSymbol;
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else {
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rankLast[nBitsToDecrease]--;
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if (huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease)
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rankLast[nBitsToDecrease] = noSymbol; /* this rank is now empty */
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}
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} /* while (totalCost > 0) */
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/* If we've removed too much weight, then we have to add it back.
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* To avoid overshooting again, we only adjust the smallest rank.
|
|
* We take the largest nodes from the lowest rank 0 and move them
|
|
* to rank 1. There's guaranteed to be enough rank 0 symbols because
|
|
* TODO.
|
|
*/
|
|
while (totalCost < 0) { /* Sometimes, cost correction overshoot */
|
|
/* special case : no rank 1 symbol (using maxNbBits-1);
|
|
* let's create one from largest rank 0 (using maxNbBits).
|
|
*/
|
|
if (rankLast[1] == noSymbol) {
|
|
while (huffNode[n].nbBits == maxNbBits) n--;
|
|
huffNode[n+1].nbBits--;
|
|
assert(n >= 0);
|
|
rankLast[1] = (U32)(n+1);
|
|
totalCost++;
|
|
continue;
|
|
}
|
|
huffNode[ rankLast[1] + 1 ].nbBits--;
|
|
rankLast[1]++;
|
|
totalCost ++;
|
|
}
|
|
} /* repay normalized cost */
|
|
} /* there are several too large elements (at least >= 2) */
|
|
|
|
return maxNbBits;
|
|
}
|
|
|
|
typedef struct {
|
|
U16 base;
|
|
U16 curr;
|
|
} rankPos;
|
|
|
|
typedef nodeElt huffNodeTable[HUF_CTABLE_WORKSPACE_SIZE_U32];
|
|
|
|
/* Number of buckets available for HUF_sort() */
|
|
#define RANK_POSITION_TABLE_SIZE 192
|
|
|
|
typedef struct {
|
|
huffNodeTable huffNodeTbl;
|
|
rankPos rankPosition[RANK_POSITION_TABLE_SIZE];
|
|
} HUF_buildCTable_wksp_tables;
|
|
|
|
/* RANK_POSITION_DISTINCT_COUNT_CUTOFF == Cutoff point in HUF_sort() buckets for which we use log2 bucketing.
|
|
* Strategy is to use as many buckets as possible for representing distinct
|
|
* counts while using the remainder to represent all "large" counts.
|
|
*
|
|
* To satisfy this requirement for 192 buckets, we can do the following:
|
|
* Let buckets 0-166 represent distinct counts of [0, 166]
|
|
* Let buckets 166 to 192 represent all remaining counts up to RANK_POSITION_MAX_COUNT_LOG using log2 bucketing.
|
|
*/
|
|
#define RANK_POSITION_MAX_COUNT_LOG 32
|
|
#define RANK_POSITION_LOG_BUCKETS_BEGIN (RANK_POSITION_TABLE_SIZE - 1) - RANK_POSITION_MAX_COUNT_LOG - 1 /* == 158 */
|
|
#define RANK_POSITION_DISTINCT_COUNT_CUTOFF RANK_POSITION_LOG_BUCKETS_BEGIN + BIT_highbit32(RANK_POSITION_LOG_BUCKETS_BEGIN) /* == 166 */
|
|
|
|
/* Return the appropriate bucket index for a given count. See definition of
|
|
* RANK_POSITION_DISTINCT_COUNT_CUTOFF for explanation of bucketing strategy.
|
|
*/
|
|
static U32 HUF_getIndex(U32 const count) {
|
|
return (count < RANK_POSITION_DISTINCT_COUNT_CUTOFF)
|
|
? count
|
|
: BIT_highbit32(count) + RANK_POSITION_LOG_BUCKETS_BEGIN;
|
|
}
|
|
|
|
/* Helper swap function for HUF_quickSortPartition() */
|
|
static void HUF_swapNodes(nodeElt* a, nodeElt* b) {
|
|
nodeElt tmp = *a;
|
|
*a = *b;
|
|
*b = tmp;
|
|
}
|
|
|
|
/* Returns 0 if the huffNode array is not sorted by descending count */
|
|
MEM_STATIC int HUF_isSorted(nodeElt huffNode[], U32 const maxSymbolValue1) {
|
|
U32 i;
|
|
for (i = 1; i < maxSymbolValue1; ++i) {
|
|
if (huffNode[i].count > huffNode[i-1].count) {
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* Insertion sort by descending order */
|
|
HINT_INLINE void HUF_insertionSort(nodeElt huffNode[], int const low, int const high) {
|
|
int i;
|
|
int const size = high-low+1;
|
|
huffNode += low;
|
|
for (i = 1; i < size; ++i) {
|
|
nodeElt const key = huffNode[i];
|
|
int j = i - 1;
|
|
while (j >= 0 && huffNode[j].count < key.count) {
|
|
huffNode[j + 1] = huffNode[j];
|
|
j--;
|
|
}
|
|
huffNode[j + 1] = key;
|
|
}
|
|
}
|
|
|
|
/* Pivot helper function for quicksort. */
|
|
static int HUF_quickSortPartition(nodeElt arr[], int const low, int const high) {
|
|
/* Simply select rightmost element as pivot. "Better" selectors like
|
|
* median-of-three don't experimentally appear to have any benefit.
|
|
*/
|
|
U32 const pivot = arr[high].count;
|
|
int i = low - 1;
|
|
int j = low;
|
|
for ( ; j < high; j++) {
|
|
if (arr[j].count > pivot) {
|
|
i++;
|
|
HUF_swapNodes(&arr[i], &arr[j]);
|
|
}
|
|
}
|
|
HUF_swapNodes(&arr[i + 1], &arr[high]);
|
|
return i + 1;
|
|
}
|
|
|
|
/* Classic quicksort by descending with partially iterative calls
|
|
* to reduce worst case callstack size.
|
|
*/
|
|
static void HUF_simpleQuickSort(nodeElt arr[], int low, int high) {
|
|
int const kInsertionSortThreshold = 8;
|
|
if (high - low < kInsertionSortThreshold) {
|
|
HUF_insertionSort(arr, low, high);
|
|
return;
|
|
}
|
|
while (low < high) {
|
|
int const idx = HUF_quickSortPartition(arr, low, high);
|
|
if (idx - low < high - idx) {
|
|
HUF_simpleQuickSort(arr, low, idx - 1);
|
|
low = idx + 1;
|
|
} else {
|
|
HUF_simpleQuickSort(arr, idx + 1, high);
|
|
high = idx - 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* HUF_sort():
|
|
* Sorts the symbols [0, maxSymbolValue] by count[symbol] in decreasing order.
|
|
* This is a typical bucket sorting strategy that uses either quicksort or insertion sort to sort each bucket.
|
|
*
|
|
* @param[out] huffNode Sorted symbols by decreasing count. Only members `.count` and `.byte` are filled.
|
|
* Must have (maxSymbolValue + 1) entries.
|
|
* @param[in] count Histogram of the symbols.
|
|
* @param[in] maxSymbolValue Maximum symbol value.
|
|
* @param rankPosition This is a scratch workspace. Must have RANK_POSITION_TABLE_SIZE entries.
|
|
*/
|
|
static void HUF_sort(nodeElt huffNode[], const unsigned count[], U32 const maxSymbolValue, rankPos rankPosition[]) {
|
|
U32 n;
|
|
U32 const maxSymbolValue1 = maxSymbolValue+1;
|
|
|
|
/* Compute base and set curr to base.
|
|
* For symbol s let lowerRank = HUF_getIndex(count[n]) and rank = lowerRank + 1.
|
|
* See HUF_getIndex to see bucketing strategy.
|
|
* We attribute each symbol to lowerRank's base value, because we want to know where
|
|
* each rank begins in the output, so for rank R we want to count ranks R+1 and above.
|
|
*/
|
|
ZSTD_memset(rankPosition, 0, sizeof(*rankPosition) * RANK_POSITION_TABLE_SIZE);
|
|
for (n = 0; n < maxSymbolValue1; ++n) {
|
|
U32 lowerRank = HUF_getIndex(count[n]);
|
|
assert(lowerRank < RANK_POSITION_TABLE_SIZE - 1);
|
|
rankPosition[lowerRank].base++;
|
|
}
|
|
|
|
assert(rankPosition[RANK_POSITION_TABLE_SIZE - 1].base == 0);
|
|
/* Set up the rankPosition table */
|
|
for (n = RANK_POSITION_TABLE_SIZE - 1; n > 0; --n) {
|
|
rankPosition[n-1].base += rankPosition[n].base;
|
|
rankPosition[n-1].curr = rankPosition[n-1].base;
|
|
}
|
|
|
|
/* Insert each symbol into their appropriate bucket, setting up rankPosition table. */
|
|
for (n = 0; n < maxSymbolValue1; ++n) {
|
|
U32 const c = count[n];
|
|
U32 const r = HUF_getIndex(c) + 1;
|
|
U32 const pos = rankPosition[r].curr++;
|
|
assert(pos < maxSymbolValue1);
|
|
huffNode[pos].count = c;
|
|
huffNode[pos].byte = (BYTE)n;
|
|
}
|
|
|
|
/* Sort each bucket. */
|
|
for (n = RANK_POSITION_DISTINCT_COUNT_CUTOFF; n < RANK_POSITION_TABLE_SIZE - 1; ++n) {
|
|
U32 const bucketSize = rankPosition[n].curr-rankPosition[n].base;
|
|
U32 const bucketStartIdx = rankPosition[n].base;
|
|
if (bucketSize > 1) {
|
|
assert(bucketStartIdx < maxSymbolValue1);
|
|
HUF_simpleQuickSort(huffNode + bucketStartIdx, 0, bucketSize-1);
|
|
}
|
|
}
|
|
|
|
assert(HUF_isSorted(huffNode, maxSymbolValue1));
|
|
}
|
|
|
|
/* HUF_buildCTable_wksp() :
|
|
* Same as HUF_buildCTable(), but using externally allocated scratch buffer.
|
|
* `workSpace` must be aligned on 4-bytes boundaries, and be at least as large as sizeof(HUF_buildCTable_wksp_tables).
|
|
*/
|
|
#define STARTNODE (HUF_SYMBOLVALUE_MAX+1)
|
|
|
|
/* HUF_buildTree():
|
|
* Takes the huffNode array sorted by HUF_sort() and builds an unlimited-depth Huffman tree.
|
|
*
|
|
* @param huffNode The array sorted by HUF_sort(). Builds the Huffman tree in this array.
|
|
* @param maxSymbolValue The maximum symbol value.
|
|
* @return The smallest node in the Huffman tree (by count).
|
|
*/
|
|
static int HUF_buildTree(nodeElt* huffNode, U32 maxSymbolValue)
|
|
{
|
|
nodeElt* const huffNode0 = huffNode - 1;
|
|
int nonNullRank;
|
|
int lowS, lowN;
|
|
int nodeNb = STARTNODE;
|
|
int n, nodeRoot;
|
|
/* init for parents */
|
|
nonNullRank = (int)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 = (U16)nodeNb;
|
|
nodeNb++; lowS-=2;
|
|
for (n=nodeNb; n<=nodeRoot; n++) huffNode[n].count = (U32)(1U<<30);
|
|
huffNode0[0].count = (U32)(1U<<31); /* fake entry, strong barrier */
|
|
|
|
/* create parents */
|
|
while (nodeNb <= nodeRoot) {
|
|
int const n1 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
|
|
int const n2 = (huffNode[lowS].count < huffNode[lowN].count) ? lowS-- : lowN++;
|
|
huffNode[nodeNb].count = huffNode[n1].count + huffNode[n2].count;
|
|
huffNode[n1].parent = huffNode[n2].parent = (U16)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;
|
|
|
|
return nonNullRank;
|
|
}
|
|
|
|
/*
|
|
* HUF_buildCTableFromTree():
|
|
* Build the CTable given the Huffman tree in huffNode.
|
|
*
|
|
* @param[out] CTable The output Huffman CTable.
|
|
* @param huffNode The Huffman tree.
|
|
* @param nonNullRank The last and smallest node in the Huffman tree.
|
|
* @param maxSymbolValue The maximum symbol value.
|
|
* @param maxNbBits The exact maximum number of bits used in the Huffman tree.
|
|
*/
|
|
static void HUF_buildCTableFromTree(HUF_CElt* CTable, nodeElt const* huffNode, int nonNullRank, U32 maxSymbolValue, U32 maxNbBits)
|
|
{
|
|
HUF_CElt* const ct = CTable + 1;
|
|
/* fill result into ctable (val, nbBits) */
|
|
int n;
|
|
U16 nbPerRank[HUF_TABLELOG_MAX+1] = {0};
|
|
U16 valPerRank[HUF_TABLELOG_MAX+1] = {0};
|
|
int const alphabetSize = (int)(maxSymbolValue + 1);
|
|
for (n=0; n<=nonNullRank; n++)
|
|
nbPerRank[huffNode[n].nbBits]++;
|
|
/* determine starting value per rank */
|
|
{ U16 min = 0;
|
|
for (n=(int)maxNbBits; n>0; n--) {
|
|
valPerRank[n] = min; /* get starting value within each rank */
|
|
min += nbPerRank[n];
|
|
min >>= 1;
|
|
} }
|
|
for (n=0; n<alphabetSize; n++)
|
|
HUF_setNbBits(ct + huffNode[n].byte, huffNode[n].nbBits); /* push nbBits per symbol, symbol order */
|
|
for (n=0; n<alphabetSize; n++)
|
|
HUF_setValue(ct + n, valPerRank[HUF_getNbBits(ct[n])]++); /* assign value within rank, symbol order */
|
|
CTable[0] = maxNbBits;
|
|
}
|
|
|
|
size_t HUF_buildCTable_wksp (HUF_CElt* CTable, const unsigned* count, U32 maxSymbolValue, U32 maxNbBits, void* workSpace, size_t wkspSize)
|
|
{
|
|
HUF_buildCTable_wksp_tables* const wksp_tables = (HUF_buildCTable_wksp_tables*)HUF_alignUpWorkspace(workSpace, &wkspSize, ZSTD_ALIGNOF(U32));
|
|
nodeElt* const huffNode0 = wksp_tables->huffNodeTbl;
|
|
nodeElt* const huffNode = huffNode0+1;
|
|
int nonNullRank;
|
|
|
|
/* safety checks */
|
|
if (wkspSize < sizeof(HUF_buildCTable_wksp_tables))
|
|
return ERROR(workSpace_tooSmall);
|
|
if (maxNbBits == 0) maxNbBits = HUF_TABLELOG_DEFAULT;
|
|
if (maxSymbolValue > HUF_SYMBOLVALUE_MAX)
|
|
return ERROR(maxSymbolValue_tooLarge);
|
|
ZSTD_memset(huffNode0, 0, sizeof(huffNodeTable));
|
|
|
|
/* sort, decreasing order */
|
|
HUF_sort(huffNode, count, maxSymbolValue, wksp_tables->rankPosition);
|
|
|
|
/* build tree */
|
|
nonNullRank = HUF_buildTree(huffNode, maxSymbolValue);
|
|
|
|
/* enforce maxTableLog */
|
|
maxNbBits = HUF_setMaxHeight(huffNode, (U32)nonNullRank, maxNbBits);
|
|
if (maxNbBits > HUF_TABLELOG_MAX) return ERROR(GENERIC); /* check fit into table */
|
|
|
|
HUF_buildCTableFromTree(CTable, huffNode, nonNullRank, maxSymbolValue, maxNbBits);
|
|
|
|
return maxNbBits;
|
|
}
|
|
|
|
size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue)
|
|
{
|
|
HUF_CElt const* ct = CTable + 1;
|
|
size_t nbBits = 0;
|
|
int s;
|
|
for (s = 0; s <= (int)maxSymbolValue; ++s) {
|
|
nbBits += HUF_getNbBits(ct[s]) * count[s];
|
|
}
|
|
return nbBits >> 3;
|
|
}
|
|
|
|
int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue) {
|
|
HUF_CElt const* ct = CTable + 1;
|
|
int bad = 0;
|
|
int s;
|
|
for (s = 0; s <= (int)maxSymbolValue; ++s) {
|
|
bad |= (count[s] != 0) & (HUF_getNbBits(ct[s]) == 0);
|
|
}
|
|
return !bad;
|
|
}
|
|
|
|
size_t HUF_compressBound(size_t size) { return HUF_COMPRESSBOUND(size); }
|
|
|
|
/* HUF_CStream_t:
|
|
* Huffman uses its own BIT_CStream_t implementation.
|
|
* There are three major differences from BIT_CStream_t:
|
|
* 1. HUF_addBits() takes a HUF_CElt (size_t) which is
|
|
* the pair (nbBits, value) in the format:
|
|
* format:
|
|
* - Bits [0, 4) = nbBits
|
|
* - Bits [4, 64 - nbBits) = 0
|
|
* - Bits [64 - nbBits, 64) = value
|
|
* 2. The bitContainer is built from the upper bits and
|
|
* right shifted. E.g. to add a new value of N bits
|
|
* you right shift the bitContainer by N, then or in
|
|
* the new value into the N upper bits.
|
|
* 3. The bitstream has two bit containers. You can add
|
|
* bits to the second container and merge them into
|
|
* the first container.
|
|
*/
|
|
|
|
#define HUF_BITS_IN_CONTAINER (sizeof(size_t) * 8)
|
|
|
|
typedef struct {
|
|
size_t bitContainer[2];
|
|
size_t bitPos[2];
|
|
|
|
BYTE* startPtr;
|
|
BYTE* ptr;
|
|
BYTE* endPtr;
|
|
} HUF_CStream_t;
|
|
|
|
/*! HUF_initCStream():
|
|
* Initializes the bitstream.
|
|
* @returns 0 or an error code.
|
|
*/
|
|
static size_t HUF_initCStream(HUF_CStream_t* bitC,
|
|
void* startPtr, size_t dstCapacity)
|
|
{
|
|
ZSTD_memset(bitC, 0, sizeof(*bitC));
|
|
bitC->startPtr = (BYTE*)startPtr;
|
|
bitC->ptr = bitC->startPtr;
|
|
bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->bitContainer[0]);
|
|
if (dstCapacity <= sizeof(bitC->bitContainer[0])) return ERROR(dstSize_tooSmall);
|
|
return 0;
|
|
}
|
|
|
|
/*! HUF_addBits():
|
|
* Adds the symbol stored in HUF_CElt elt to the bitstream.
|
|
*
|
|
* @param elt The element we're adding. This is a (nbBits, value) pair.
|
|
* See the HUF_CStream_t docs for the format.
|
|
* @param idx Insert into the bitstream at this idx.
|
|
* @param kFast This is a template parameter. If the bitstream is guaranteed
|
|
* to have at least 4 unused bits after this call it may be 1,
|
|
* otherwise it must be 0. HUF_addBits() is faster when fast is set.
|
|
*/
|
|
FORCE_INLINE_TEMPLATE void HUF_addBits(HUF_CStream_t* bitC, HUF_CElt elt, int idx, int kFast)
|
|
{
|
|
assert(idx <= 1);
|
|
assert(HUF_getNbBits(elt) <= HUF_TABLELOG_ABSOLUTEMAX);
|
|
/* This is efficient on x86-64 with BMI2 because shrx
|
|
* only reads the low 6 bits of the register. The compiler
|
|
* knows this and elides the mask. When fast is set,
|
|
* every operation can use the same value loaded from elt.
|
|
*/
|
|
bitC->bitContainer[idx] >>= HUF_getNbBits(elt);
|
|
bitC->bitContainer[idx] |= kFast ? HUF_getValueFast(elt) : HUF_getValue(elt);
|
|
/* We only read the low 8 bits of bitC->bitPos[idx] so it
|
|
* doesn't matter that the high bits have noise from the value.
|
|
*/
|
|
bitC->bitPos[idx] += HUF_getNbBitsFast(elt);
|
|
assert((bitC->bitPos[idx] & 0xFF) <= HUF_BITS_IN_CONTAINER);
|
|
/* The last 4-bits of elt are dirty if fast is set,
|
|
* so we must not be overwriting bits that have already been
|
|
* inserted into the bit container.
|
|
*/
|
|
#if DEBUGLEVEL >= 1
|
|
{
|
|
size_t const nbBits = HUF_getNbBits(elt);
|
|
size_t const dirtyBits = nbBits == 0 ? 0 : BIT_highbit32((U32)nbBits) + 1;
|
|
(void)dirtyBits;
|
|
/* Middle bits are 0. */
|
|
assert(((elt >> dirtyBits) << (dirtyBits + nbBits)) == 0);
|
|
/* We didn't overwrite any bits in the bit container. */
|
|
assert(!kFast || (bitC->bitPos[idx] & 0xFF) <= HUF_BITS_IN_CONTAINER);
|
|
(void)dirtyBits;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE void HUF_zeroIndex1(HUF_CStream_t* bitC)
|
|
{
|
|
bitC->bitContainer[1] = 0;
|
|
bitC->bitPos[1] = 0;
|
|
}
|
|
|
|
/*! HUF_mergeIndex1() :
|
|
* Merges the bit container @ index 1 into the bit container @ index 0
|
|
* and zeros the bit container @ index 1.
|
|
*/
|
|
FORCE_INLINE_TEMPLATE void HUF_mergeIndex1(HUF_CStream_t* bitC)
|
|
{
|
|
assert((bitC->bitPos[1] & 0xFF) < HUF_BITS_IN_CONTAINER);
|
|
bitC->bitContainer[0] >>= (bitC->bitPos[1] & 0xFF);
|
|
bitC->bitContainer[0] |= bitC->bitContainer[1];
|
|
bitC->bitPos[0] += bitC->bitPos[1];
|
|
assert((bitC->bitPos[0] & 0xFF) <= HUF_BITS_IN_CONTAINER);
|
|
}
|
|
|
|
/*! HUF_flushBits() :
|
|
* Flushes the bits in the bit container @ index 0.
|
|
*
|
|
* @post bitPos will be < 8.
|
|
* @param kFast If kFast is set then we must know a-priori that
|
|
* the bit container will not overflow.
|
|
*/
|
|
FORCE_INLINE_TEMPLATE void HUF_flushBits(HUF_CStream_t* bitC, int kFast)
|
|
{
|
|
/* The upper bits of bitPos are noisy, so we must mask by 0xFF. */
|
|
size_t const nbBits = bitC->bitPos[0] & 0xFF;
|
|
size_t const nbBytes = nbBits >> 3;
|
|
/* The top nbBits bits of bitContainer are the ones we need. */
|
|
size_t const bitContainer = bitC->bitContainer[0] >> (HUF_BITS_IN_CONTAINER - nbBits);
|
|
/* Mask bitPos to account for the bytes we consumed. */
|
|
bitC->bitPos[0] &= 7;
|
|
assert(nbBits > 0);
|
|
assert(nbBits <= sizeof(bitC->bitContainer[0]) * 8);
|
|
assert(bitC->ptr <= bitC->endPtr);
|
|
MEM_writeLEST(bitC->ptr, bitContainer);
|
|
bitC->ptr += nbBytes;
|
|
assert(!kFast || bitC->ptr <= bitC->endPtr);
|
|
if (!kFast && bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
|
|
/* bitContainer doesn't need to be modified because the leftover
|
|
* bits are already the top bitPos bits. And we don't care about
|
|
* noise in the lower values.
|
|
*/
|
|
}
|
|
|
|
/*! HUF_endMark()
|
|
* @returns The Huffman stream end mark: A 1-bit value = 1.
|
|
*/
|
|
static HUF_CElt HUF_endMark(void)
|
|
{
|
|
HUF_CElt endMark;
|
|
HUF_setNbBits(&endMark, 1);
|
|
HUF_setValue(&endMark, 1);
|
|
return endMark;
|
|
}
|
|
|
|
/*! HUF_closeCStream() :
|
|
* @return Size of CStream, in bytes,
|
|
* or 0 if it could not fit into dstBuffer */
|
|
static size_t HUF_closeCStream(HUF_CStream_t* bitC)
|
|
{
|
|
HUF_addBits(bitC, HUF_endMark(), /* idx */ 0, /* kFast */ 0);
|
|
HUF_flushBits(bitC, /* kFast */ 0);
|
|
{
|
|
size_t const nbBits = bitC->bitPos[0] & 0xFF;
|
|
if (bitC->ptr >= bitC->endPtr) return 0; /* overflow detected */
|
|
return (bitC->ptr - bitC->startPtr) + (nbBits > 0);
|
|
}
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE void
|
|
HUF_encodeSymbol(HUF_CStream_t* bitCPtr, U32 symbol, const HUF_CElt* CTable, int idx, int fast)
|
|
{
|
|
HUF_addBits(bitCPtr, CTable[symbol], idx, fast);
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE void
|
|
HUF_compress1X_usingCTable_internal_body_loop(HUF_CStream_t* bitC,
|
|
const BYTE* ip, size_t srcSize,
|
|
const HUF_CElt* ct,
|
|
int kUnroll, int kFastFlush, int kLastFast)
|
|
{
|
|
/* Join to kUnroll */
|
|
int n = (int)srcSize;
|
|
int rem = n % kUnroll;
|
|
if (rem > 0) {
|
|
for (; rem > 0; --rem) {
|
|
HUF_encodeSymbol(bitC, ip[--n], ct, 0, /* fast */ 0);
|
|
}
|
|
HUF_flushBits(bitC, kFastFlush);
|
|
}
|
|
assert(n % kUnroll == 0);
|
|
|
|
/* Join to 2 * kUnroll */
|
|
if (n % (2 * kUnroll)) {
|
|
int u;
|
|
for (u = 1; u < kUnroll; ++u) {
|
|
HUF_encodeSymbol(bitC, ip[n - u], ct, 0, 1);
|
|
}
|
|
HUF_encodeSymbol(bitC, ip[n - kUnroll], ct, 0, kLastFast);
|
|
HUF_flushBits(bitC, kFastFlush);
|
|
n -= kUnroll;
|
|
}
|
|
assert(n % (2 * kUnroll) == 0);
|
|
|
|
for (; n>0; n-= 2 * kUnroll) {
|
|
/* Encode kUnroll symbols into the bitstream @ index 0. */
|
|
int u;
|
|
for (u = 1; u < kUnroll; ++u) {
|
|
HUF_encodeSymbol(bitC, ip[n - u], ct, /* idx */ 0, /* fast */ 1);
|
|
}
|
|
HUF_encodeSymbol(bitC, ip[n - kUnroll], ct, /* idx */ 0, /* fast */ kLastFast);
|
|
HUF_flushBits(bitC, kFastFlush);
|
|
/* Encode kUnroll symbols into the bitstream @ index 1.
|
|
* This allows us to start filling the bit container
|
|
* without any data dependencies.
|
|
*/
|
|
HUF_zeroIndex1(bitC);
|
|
for (u = 1; u < kUnroll; ++u) {
|
|
HUF_encodeSymbol(bitC, ip[n - kUnroll - u], ct, /* idx */ 1, /* fast */ 1);
|
|
}
|
|
HUF_encodeSymbol(bitC, ip[n - kUnroll - kUnroll], ct, /* idx */ 1, /* fast */ kLastFast);
|
|
/* Merge bitstream @ index 1 into the bitstream @ index 0 */
|
|
HUF_mergeIndex1(bitC);
|
|
HUF_flushBits(bitC, kFastFlush);
|
|
}
|
|
assert(n == 0);
|
|
|
|
}
|
|
|
|
/*
|
|
* Returns a tight upper bound on the output space needed by Huffman
|
|
* with 8 bytes buffer to handle over-writes. If the output is at least
|
|
* this large we don't need to do bounds checks during Huffman encoding.
|
|
*/
|
|
static size_t HUF_tightCompressBound(size_t srcSize, size_t tableLog)
|
|
{
|
|
return ((srcSize * tableLog) >> 3) + 8;
|
|
}
|
|
|
|
|
|
FORCE_INLINE_TEMPLATE size_t
|
|
HUF_compress1X_usingCTable_internal_body(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable)
|
|
{
|
|
U32 const tableLog = (U32)CTable[0];
|
|
HUF_CElt const* ct = CTable + 1;
|
|
const BYTE* ip = (const BYTE*) src;
|
|
BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstSize;
|
|
BYTE* op = ostart;
|
|
HUF_CStream_t bitC;
|
|
|
|
/* init */
|
|
if (dstSize < 8) return 0; /* not enough space to compress */
|
|
{ size_t const initErr = HUF_initCStream(&bitC, op, (size_t)(oend-op));
|
|
if (HUF_isError(initErr)) return 0; }
|
|
|
|
if (dstSize < HUF_tightCompressBound(srcSize, (size_t)tableLog) || tableLog > 11)
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ MEM_32bits() ? 2 : 4, /* kFast */ 0, /* kLastFast */ 0);
|
|
else {
|
|
if (MEM_32bits()) {
|
|
switch (tableLog) {
|
|
case 11:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 2, /* kFastFlush */ 1, /* kLastFast */ 0);
|
|
break;
|
|
case 10: ZSTD_FALLTHROUGH;
|
|
case 9: ZSTD_FALLTHROUGH;
|
|
case 8:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 2, /* kFastFlush */ 1, /* kLastFast */ 1);
|
|
break;
|
|
case 7: ZSTD_FALLTHROUGH;
|
|
default:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 3, /* kFastFlush */ 1, /* kLastFast */ 1);
|
|
break;
|
|
}
|
|
} else {
|
|
switch (tableLog) {
|
|
case 11:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 5, /* kFastFlush */ 1, /* kLastFast */ 0);
|
|
break;
|
|
case 10:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 5, /* kFastFlush */ 1, /* kLastFast */ 1);
|
|
break;
|
|
case 9:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 6, /* kFastFlush */ 1, /* kLastFast */ 0);
|
|
break;
|
|
case 8:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 7, /* kFastFlush */ 1, /* kLastFast */ 0);
|
|
break;
|
|
case 7:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 8, /* kFastFlush */ 1, /* kLastFast */ 0);
|
|
break;
|
|
case 6: ZSTD_FALLTHROUGH;
|
|
default:
|
|
HUF_compress1X_usingCTable_internal_body_loop(&bitC, ip, srcSize, ct, /* kUnroll */ 9, /* kFastFlush */ 1, /* kLastFast */ 1);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
assert(bitC.ptr <= bitC.endPtr);
|
|
|
|
return HUF_closeCStream(&bitC);
|
|
}
|
|
|
|
#if DYNAMIC_BMI2
|
|
|
|
static BMI2_TARGET_ATTRIBUTE size_t
|
|
HUF_compress1X_usingCTable_internal_bmi2(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable)
|
|
{
|
|
return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
|
|
}
|
|
|
|
static size_t
|
|
HUF_compress1X_usingCTable_internal_default(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable)
|
|
{
|
|
return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
|
|
}
|
|
|
|
static size_t
|
|
HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable, const int bmi2)
|
|
{
|
|
if (bmi2) {
|
|
return HUF_compress1X_usingCTable_internal_bmi2(dst, dstSize, src, srcSize, CTable);
|
|
}
|
|
return HUF_compress1X_usingCTable_internal_default(dst, dstSize, src, srcSize, CTable);
|
|
}
|
|
|
|
#else
|
|
|
|
static size_t
|
|
HUF_compress1X_usingCTable_internal(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable, const int bmi2)
|
|
{
|
|
(void)bmi2;
|
|
return HUF_compress1X_usingCTable_internal_body(dst, dstSize, src, srcSize, CTable);
|
|
}
|
|
|
|
#endif
|
|
|
|
size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
|
|
{
|
|
return HUF_compress1X_usingCTable_bmi2(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
|
|
}
|
|
|
|
size_t HUF_compress1X_usingCTable_bmi2(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int bmi2)
|
|
{
|
|
return HUF_compress1X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, bmi2);
|
|
}
|
|
|
|
static size_t
|
|
HUF_compress4X_usingCTable_internal(void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
const HUF_CElt* CTable, int bmi2)
|
|
{
|
|
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 */
|
|
|
|
assert(op <= oend);
|
|
{ CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
|
|
if (cSize == 0 || cSize > 65535) return 0;
|
|
MEM_writeLE16(ostart, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
assert(op <= oend);
|
|
{ CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
|
|
if (cSize == 0 || cSize > 65535) return 0;
|
|
MEM_writeLE16(ostart+2, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
assert(op <= oend);
|
|
{ CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, segmentSize, CTable, bmi2) );
|
|
if (cSize == 0 || cSize > 65535) return 0;
|
|
MEM_writeLE16(ostart+4, (U16)cSize);
|
|
op += cSize;
|
|
}
|
|
|
|
ip += segmentSize;
|
|
assert(op <= oend);
|
|
assert(ip <= iend);
|
|
{ CHECK_V_F(cSize, HUF_compress1X_usingCTable_internal(op, (size_t)(oend-op), ip, (size_t)(iend-ip), CTable, bmi2) );
|
|
if (cSize == 0 || cSize > 65535) return 0;
|
|
op += cSize;
|
|
}
|
|
|
|
return (size_t)(op-ostart);
|
|
}
|
|
|
|
size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable)
|
|
{
|
|
return HUF_compress4X_usingCTable_bmi2(dst, dstSize, src, srcSize, CTable, /* bmi2 */ 0);
|
|
}
|
|
|
|
size_t HUF_compress4X_usingCTable_bmi2(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int bmi2)
|
|
{
|
|
return HUF_compress4X_usingCTable_internal(dst, dstSize, src, srcSize, CTable, bmi2);
|
|
}
|
|
|
|
typedef enum { HUF_singleStream, HUF_fourStreams } HUF_nbStreams_e;
|
|
|
|
static size_t HUF_compressCTable_internal(
|
|
BYTE* const ostart, BYTE* op, BYTE* const oend,
|
|
const void* src, size_t srcSize,
|
|
HUF_nbStreams_e nbStreams, const HUF_CElt* CTable, const int bmi2)
|
|
{
|
|
size_t const cSize = (nbStreams==HUF_singleStream) ?
|
|
HUF_compress1X_usingCTable_internal(op, (size_t)(oend - op), src, srcSize, CTable, bmi2) :
|
|
HUF_compress4X_usingCTable_internal(op, (size_t)(oend - op), src, srcSize, CTable, bmi2);
|
|
if (HUF_isError(cSize)) { return cSize; }
|
|
if (cSize==0) { return 0; } /* uncompressible */
|
|
op += cSize;
|
|
/* check compressibility */
|
|
assert(op >= ostart);
|
|
if ((size_t)(op-ostart) >= srcSize-1) { return 0; }
|
|
return (size_t)(op-ostart);
|
|
}
|
|
|
|
typedef struct {
|
|
unsigned count[HUF_SYMBOLVALUE_MAX + 1];
|
|
HUF_CElt CTable[HUF_CTABLE_SIZE_ST(HUF_SYMBOLVALUE_MAX)];
|
|
union {
|
|
HUF_buildCTable_wksp_tables buildCTable_wksp;
|
|
HUF_WriteCTableWksp writeCTable_wksp;
|
|
U32 hist_wksp[HIST_WKSP_SIZE_U32];
|
|
} wksps;
|
|
} HUF_compress_tables_t;
|
|
|
|
#define SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE 4096
|
|
#define SUSPECT_INCOMPRESSIBLE_SAMPLE_RATIO 10 /* Must be >= 2 */
|
|
|
|
/* HUF_compress_internal() :
|
|
* `workSpace_align4` must be aligned on 4-bytes boundaries,
|
|
* and occupies the same space as a table of HUF_WORKSPACE_SIZE_U64 unsigned */
|
|
static size_t
|
|
HUF_compress_internal (void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
unsigned maxSymbolValue, unsigned huffLog,
|
|
HUF_nbStreams_e nbStreams,
|
|
void* workSpace, size_t wkspSize,
|
|
HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat,
|
|
const int bmi2, unsigned suspectUncompressible)
|
|
{
|
|
HUF_compress_tables_t* const table = (HUF_compress_tables_t*)HUF_alignUpWorkspace(workSpace, &wkspSize, ZSTD_ALIGNOF(size_t));
|
|
BYTE* const ostart = (BYTE*)dst;
|
|
BYTE* const oend = ostart + dstSize;
|
|
BYTE* op = ostart;
|
|
|
|
HUF_STATIC_ASSERT(sizeof(*table) + HUF_WORKSPACE_MAX_ALIGNMENT <= HUF_WORKSPACE_SIZE);
|
|
|
|
/* checks & inits */
|
|
if (wkspSize < sizeof(*table)) return ERROR(workSpace_tooSmall);
|
|
if (!srcSize) return 0; /* Uncompressed */
|
|
if (!dstSize) return 0; /* cannot fit anything 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 > HUF_SYMBOLVALUE_MAX) return ERROR(maxSymbolValue_tooLarge);
|
|
if (!maxSymbolValue) maxSymbolValue = HUF_SYMBOLVALUE_MAX;
|
|
if (!huffLog) huffLog = HUF_TABLELOG_DEFAULT;
|
|
|
|
/* Heuristic : If old table is valid, use it for small inputs */
|
|
if (preferRepeat && repeat && *repeat == HUF_repeat_valid) {
|
|
return HUF_compressCTable_internal(ostart, op, oend,
|
|
src, srcSize,
|
|
nbStreams, oldHufTable, bmi2);
|
|
}
|
|
|
|
/* If uncompressible data is suspected, do a smaller sampling first */
|
|
DEBUG_STATIC_ASSERT(SUSPECT_INCOMPRESSIBLE_SAMPLE_RATIO >= 2);
|
|
if (suspectUncompressible && srcSize >= (SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE * SUSPECT_INCOMPRESSIBLE_SAMPLE_RATIO)) {
|
|
size_t largestTotal = 0;
|
|
{ unsigned maxSymbolValueBegin = maxSymbolValue;
|
|
CHECK_V_F(largestBegin, HIST_count_simple (table->count, &maxSymbolValueBegin, (const BYTE*)src, SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE) );
|
|
largestTotal += largestBegin;
|
|
}
|
|
{ unsigned maxSymbolValueEnd = maxSymbolValue;
|
|
CHECK_V_F(largestEnd, HIST_count_simple (table->count, &maxSymbolValueEnd, (const BYTE*)src + srcSize - SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE, SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE) );
|
|
largestTotal += largestEnd;
|
|
}
|
|
if (largestTotal <= ((2 * SUSPECT_INCOMPRESSIBLE_SAMPLE_SIZE) >> 7)+4) return 0; /* heuristic : probably not compressible enough */
|
|
}
|
|
|
|
/* Scan input and build symbol stats */
|
|
{ CHECK_V_F(largest, HIST_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, table->wksps.hist_wksp, sizeof(table->wksps.hist_wksp)) );
|
|
if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; } /* single symbol, rle */
|
|
if (largest <= (srcSize >> 7)+4) return 0; /* heuristic : probably not compressible enough */
|
|
}
|
|
|
|
/* Check validity of previous table */
|
|
if ( repeat
|
|
&& *repeat == HUF_repeat_check
|
|
&& !HUF_validateCTable(oldHufTable, table->count, maxSymbolValue)) {
|
|
*repeat = HUF_repeat_none;
|
|
}
|
|
/* Heuristic : use existing table for small inputs */
|
|
if (preferRepeat && repeat && *repeat != HUF_repeat_none) {
|
|
return HUF_compressCTable_internal(ostart, op, oend,
|
|
src, srcSize,
|
|
nbStreams, oldHufTable, bmi2);
|
|
}
|
|
|
|
/* Build Huffman Tree */
|
|
huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
|
|
{ size_t const maxBits = HUF_buildCTable_wksp(table->CTable, table->count,
|
|
maxSymbolValue, huffLog,
|
|
&table->wksps.buildCTable_wksp, sizeof(table->wksps.buildCTable_wksp));
|
|
CHECK_F(maxBits);
|
|
huffLog = (U32)maxBits;
|
|
}
|
|
/* Zero unused symbols in CTable, so we can check it for validity */
|
|
{
|
|
size_t const ctableSize = HUF_CTABLE_SIZE_ST(maxSymbolValue);
|
|
size_t const unusedSize = sizeof(table->CTable) - ctableSize * sizeof(HUF_CElt);
|
|
ZSTD_memset(table->CTable + ctableSize, 0, unusedSize);
|
|
}
|
|
|
|
/* Write table description header */
|
|
{ CHECK_V_F(hSize, HUF_writeCTable_wksp(op, dstSize, table->CTable, maxSymbolValue, huffLog,
|
|
&table->wksps.writeCTable_wksp, sizeof(table->wksps.writeCTable_wksp)) );
|
|
/* Check if using previous huffman table is beneficial */
|
|
if (repeat && *repeat != HUF_repeat_none) {
|
|
size_t const oldSize = HUF_estimateCompressedSize(oldHufTable, table->count, maxSymbolValue);
|
|
size_t const newSize = HUF_estimateCompressedSize(table->CTable, table->count, maxSymbolValue);
|
|
if (oldSize <= hSize + newSize || hSize + 12 >= srcSize) {
|
|
return HUF_compressCTable_internal(ostart, op, oend,
|
|
src, srcSize,
|
|
nbStreams, oldHufTable, bmi2);
|
|
} }
|
|
|
|
/* Use the new huffman table */
|
|
if (hSize + 12ul >= srcSize) { return 0; }
|
|
op += hSize;
|
|
if (repeat) { *repeat = HUF_repeat_none; }
|
|
if (oldHufTable)
|
|
ZSTD_memcpy(oldHufTable, table->CTable, sizeof(table->CTable)); /* Save new table */
|
|
}
|
|
return HUF_compressCTable_internal(ostart, op, oend,
|
|
src, srcSize,
|
|
nbStreams, table->CTable, bmi2);
|
|
}
|
|
|
|
|
|
size_t HUF_compress1X_wksp (void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
unsigned maxSymbolValue, unsigned huffLog,
|
|
void* workSpace, size_t wkspSize)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize,
|
|
maxSymbolValue, huffLog, HUF_singleStream,
|
|
workSpace, wkspSize,
|
|
NULL, NULL, 0, 0 /*bmi2*/, 0);
|
|
}
|
|
|
|
size_t HUF_compress1X_repeat (void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
unsigned maxSymbolValue, unsigned huffLog,
|
|
void* workSpace, size_t wkspSize,
|
|
HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat,
|
|
int bmi2, unsigned suspectUncompressible)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize,
|
|
maxSymbolValue, huffLog, HUF_singleStream,
|
|
workSpace, wkspSize, hufTable,
|
|
repeat, preferRepeat, bmi2, suspectUncompressible);
|
|
}
|
|
|
|
/* HUF_compress4X_repeat():
|
|
* compress input using 4 streams.
|
|
* provide workspace to generate compression tables */
|
|
size_t HUF_compress4X_wksp (void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
unsigned maxSymbolValue, unsigned huffLog,
|
|
void* workSpace, size_t wkspSize)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize,
|
|
maxSymbolValue, huffLog, HUF_fourStreams,
|
|
workSpace, wkspSize,
|
|
NULL, NULL, 0, 0 /*bmi2*/, 0);
|
|
}
|
|
|
|
/* HUF_compress4X_repeat():
|
|
* compress input using 4 streams.
|
|
* consider skipping quickly
|
|
* re-use an existing huffman compression table */
|
|
size_t HUF_compress4X_repeat (void* dst, size_t dstSize,
|
|
const void* src, size_t srcSize,
|
|
unsigned maxSymbolValue, unsigned huffLog,
|
|
void* workSpace, size_t wkspSize,
|
|
HUF_CElt* hufTable, HUF_repeat* repeat, int preferRepeat, int bmi2, unsigned suspectUncompressible)
|
|
{
|
|
return HUF_compress_internal(dst, dstSize, src, srcSize,
|
|
maxSymbolValue, huffLog, HUF_fourStreams,
|
|
workSpace, wkspSize,
|
|
hufTable, repeat, preferRepeat, bmi2, suspectUncompressible);
|
|
}
|
|
|