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Diffstat (limited to 'lib/zstd/fse_compress.c')
| -rw-r--r-- | lib/zstd/fse_compress.c | 795 |
1 files changed, 0 insertions, 795 deletions
diff --git a/lib/zstd/fse_compress.c b/lib/zstd/fse_compress.c deleted file mode 100644 index ef3d1741d532..000000000000 --- a/lib/zstd/fse_compress.c +++ /dev/null @@ -1,795 +0,0 @@ -/* - * FSE : Finite State Entropy encoder - * Copyright (C) 2013-2015, 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. - * - * This program is free software; you can redistribute it and/or modify it under - * the terms of the GNU General Public License version 2 as published by the - * Free Software Foundation. This program is dual-licensed; you may select - * either version 2 of the GNU General Public License ("GPL") or BSD license - * ("BSD"). - * - * You can contact the author at : - * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy - */ - -/* ************************************************************** -* Compiler specifics -****************************************************************/ -#define FORCE_INLINE static __always_inline - -/* ************************************************************** -* Includes -****************************************************************/ -#include "bitstream.h" -#include "fse.h" -#include <linux/compiler.h> -#include <linux/kernel.h> -#include <linux/math64.h> -#include <linux/string.h> /* memcpy, memset */ - -/* ************************************************************** -* Error Management -****************************************************************/ -#define FSE_STATIC_ASSERT(c) \ - { \ - enum { FSE_static_assert = 1 / (int)(!!(c)) }; \ - } /* use only *after* variable declarations */ - -/* ************************************************************** -* Templates -****************************************************************/ -/* - designed to be included - for type-specific functions (template emulation in C) - Objective is to write these functions only once, for improved maintenance -*/ - -/* safety checks */ -#ifndef FSE_FUNCTION_EXTENSION -#error "FSE_FUNCTION_EXTENSION must be defined" -#endif -#ifndef FSE_FUNCTION_TYPE -#error "FSE_FUNCTION_TYPE must be defined" -#endif - -/* Function names */ -#define FSE_CAT(X, Y) X##Y -#define FSE_FUNCTION_NAME(X, Y) FSE_CAT(X, Y) -#define FSE_TYPE_NAME(X, Y) FSE_CAT(X, Y) - -/* Function templates */ - -/* FSE_buildCTable_wksp() : - * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`). - * wkspSize should be sized to handle worst case situation, which is `1<<max_tableLog * sizeof(FSE_FUNCTION_TYPE)` - * workSpace must also be properly aligned with FSE_FUNCTION_TYPE requirements - */ -size_t FSE_buildCTable_wksp(FSE_CTable *ct, const short *normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void *workspace, size_t workspaceSize) -{ - U32 const tableSize = 1 << tableLog; - U32 const tableMask = tableSize - 1; - void *const ptr = ct; - U16 *const tableU16 = ((U16 *)ptr) + 2; - void *const FSCT = ((U32 *)ptr) + 1 /* header */ + (tableLog ? tableSize >> 1 : 1); - FSE_symbolCompressionTransform *const symbolTT = (FSE_symbolCompressionTransform *)(FSCT); - U32 const step = FSE_TABLESTEP(tableSize); - U32 highThreshold = tableSize - 1; - - U32 *cumul; - FSE_FUNCTION_TYPE *tableSymbol; - size_t spaceUsed32 = 0; - - cumul = (U32 *)workspace + spaceUsed32; - spaceUsed32 += FSE_MAX_SYMBOL_VALUE + 2; - tableSymbol = (FSE_FUNCTION_TYPE *)((U32 *)workspace + spaceUsed32); - spaceUsed32 += ALIGN(sizeof(FSE_FUNCTION_TYPE) * ((size_t)1 << tableLog), sizeof(U32)) >> 2; - - if ((spaceUsed32 << 2) > workspaceSize) - return ERROR(tableLog_tooLarge); - workspace = (U32 *)workspace + spaceUsed32; - workspaceSize -= (spaceUsed32 << 2); - - /* CTable header */ - tableU16[-2] = (U16)tableLog; - tableU16[-1] = (U16)maxSymbolValue; - - /* For explanations on how to distribute symbol values over the table : - * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */ - - /* symbol start positions */ - { - U32 u; - cumul[0] = 0; - for (u = 1; u <= maxSymbolValue + 1; u++) { - if (normalizedCounter[u - 1] == -1) { /* Low proba symbol */ - cumul[u] = cumul[u - 1] + 1; - tableSymbol[highThreshold--] = (FSE_FUNCTION_TYPE)(u - 1); - } else { - cumul[u] = cumul[u - 1] + normalizedCounter[u - 1]; - } - } - cumul[maxSymbolValue + 1] = tableSize + 1; - } - - /* Spread symbols */ - { - U32 position = 0; - U32 symbol; - for (symbol = 0; symbol <= maxSymbolValue; symbol++) { - int nbOccurences; - for (nbOccurences = 0; nbOccurences < normalizedCounter[symbol]; nbOccurences++) { - tableSymbol[position] = (FSE_FUNCTION_TYPE)symbol; - position = (position + step) & tableMask; - while (position > highThreshold) - position = (position + step) & tableMask; /* Low proba area */ - } - } - - if (position != 0) - return ERROR(GENERIC); /* Must have gone through all positions */ - } - - /* Build table */ - { - U32 u; - for (u = 0; u < tableSize; u++) { - FSE_FUNCTION_TYPE s = tableSymbol[u]; /* note : static analyzer may not understand tableSymbol is properly initialized */ - tableU16[cumul[s]++] = (U16)(tableSize + u); /* TableU16 : sorted by symbol order; gives next state value */ - } - } - - /* Build Symbol Transformation Table */ - { - unsigned total = 0; - unsigned s; - for (s = 0; s <= maxSymbolValue; s++) { - switch (normalizedCounter[s]) { - case 0: break; - - case -1: - case 1: - symbolTT[s].deltaNbBits = (tableLog << 16) - (1 << tableLog); - symbolTT[s].deltaFindState = total - 1; - total++; - break; - default: { - U32 const maxBitsOut = tableLog - BIT_highbit32(normalizedCounter[s] - 1); - U32 const minStatePlus = normalizedCounter[s] << maxBitsOut; - symbolTT[s].deltaNbBits = (maxBitsOut << 16) - minStatePlus; - symbolTT[s].deltaFindState = total - normalizedCounter[s]; - total += normalizedCounter[s]; - } - } - } - } - - return 0; -} - -/*-************************************************************** -* FSE NCount encoding-decoding -****************************************************************/ -size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog) -{ - size_t const maxHeaderSize = (((maxSymbolValue + 1) * tableLog) >> 3) + 3; - return maxSymbolValue ? maxHeaderSize : FSE_NCOUNTBOUND; /* maxSymbolValue==0 ? use default */ -} - -static size_t FSE_writeNCount_generic(void *header, size_t headerBufferSize, const short *normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, - unsigned writeIsSafe) -{ - BYTE *const ostart = (BYTE *)header; - BYTE *out = ostart; - BYTE *const oend = ostart + headerBufferSize; - int nbBits; - const int tableSize = 1 << tableLog; - int remaining; - int threshold; - U32 bitStream; - int bitCount; - unsigned charnum = 0; - int previous0 = 0; - - bitStream = 0; - bitCount = 0; - /* Table Size */ - bitStream += (tableLog - FSE_MIN_TABLELOG) << bitCount; - bitCount += 4; - - /* Init */ - remaining = tableSize + 1; /* +1 for extra accuracy */ - threshold = tableSize; - nbBits = tableLog + 1; - - while (remaining > 1) { /* stops at 1 */ - if (previous0) { - unsigned start = charnum; - while (!normalizedCounter[charnum]) - charnum++; - while (charnum >= start + 24) { - start += 24; - bitStream += 0xFFFFU << bitCount; - if ((!writeIsSafe) && (out > oend - 2)) - return ERROR(dstSize_tooSmall); /* Buffer overflow */ - out[0] = (BYTE)bitStream; - out[1] = (BYTE)(bitStream >> 8); - out += 2; - bitStream >>= 16; - } - while (charnum >= start + 3) { - start += 3; - bitStream += 3 << bitCount; - bitCount += 2; - } - bitStream += (charnum - start) << bitCount; - bitCount += 2; - if (bitCount > 16) { - if ((!writeIsSafe) && (out > oend - 2)) - return ERROR(dstSize_tooSmall); /* Buffer overflow */ - out[0] = (BYTE)bitStream; - out[1] = (BYTE)(bitStream >> 8); - out += 2; - bitStream >>= 16; - bitCount -= 16; - } - } - { - int count = normalizedCounter[charnum++]; - int const max = (2 * threshold - 1) - remaining; - remaining -= count < 0 ? -count : count; - count++; /* +1 for extra accuracy */ - if (count >= threshold) - count += max; /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */ - bitStream += count << bitCount; - bitCount += nbBits; - bitCount -= (count < max); - previous0 = (count == 1); - if (remaining < 1) - return ERROR(GENERIC); - while (remaining < threshold) - nbBits--, threshold >>= 1; - } - if (bitCount > 16) { - if ((!writeIsSafe) && (out > oend - 2)) - return ERROR(dstSize_tooSmall); /* Buffer overflow */ - out[0] = (BYTE)bitStream; - out[1] = (BYTE)(bitStream >> 8); - out += 2; - bitStream >>= 16; - bitCount -= 16; - } - } - - /* flush remaining bitStream */ - if ((!writeIsSafe) && (out > oend - 2)) - return ERROR(dstSize_tooSmall); /* Buffer overflow */ - out[0] = (BYTE)bitStream; - out[1] = (BYTE)(bitStream >> 8); - out += (bitCount + 7) / 8; - - if (charnum > maxSymbolValue + 1) - return ERROR(GENERIC); - - return (out - ostart); -} - -size_t FSE_writeNCount(void *buffer, size_t bufferSize, const short *normalizedCounter, unsigned maxSymbolValue, unsigned tableLog) -{ - if (tableLog > FSE_MAX_TABLELOG) - return ERROR(tableLog_tooLarge); /* Unsupported */ - if (tableLog < FSE_MIN_TABLELOG) - return ERROR(GENERIC); /* Unsupported */ - - if (bufferSize < FSE_NCountWriteBound(maxSymbolValue, tableLog)) - return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 0); - - return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1); -} - -/*-************************************************************** -* Counting histogram -****************************************************************/ -/*! FSE_count_simple - This function counts byte values within `src`, and store the histogram into table `count`. - It doesn't use any additional memory. - But this function is unsafe : it doesn't check that all values within `src` can fit into `count`. - For this reason, prefer using a table `count` with 256 elements. - @return : count of most numerous element -*/ -size_t FSE_count_simple(unsigned *count, unsigned *maxSymbolValuePtr, const void *src, size_t srcSize) -{ - const BYTE *ip = (const BYTE *)src; - const BYTE *const end = ip + srcSize; - unsigned maxSymbolValue = *maxSymbolValuePtr; - unsigned max = 0; - - memset(count, 0, (maxSymbolValue + 1) * sizeof(*count)); - if (srcSize == 0) { - *maxSymbolValuePtr = 0; - return 0; - } - - while (ip < end) - count[*ip++]++; - - while (!count[maxSymbolValue]) - maxSymbolValue--; - *maxSymbolValuePtr = maxSymbolValue; - - { - U32 s; - for (s = 0; s <= maxSymbolValue; s++) - if (count[s] > max) - max = count[s]; - } - - return (size_t)max; -} - -/* FSE_count_parallel_wksp() : - * Same as FSE_count_parallel(), but using an externally provided scratch buffer. - * `workSpace` size must be a minimum of `1024 * sizeof(unsigned)`` */ -static size_t FSE_count_parallel_wksp(unsigned *count, unsigned *maxSymbolValuePtr, const void *source, size_t sourceSize, unsigned checkMax, - unsigned *const workSpace) -{ - const BYTE *ip = (const BYTE *)source; - const BYTE *const iend = ip + sourceSize; - unsigned maxSymbolValue = *maxSymbolValuePtr; - unsigned max = 0; - U32 *const Counting1 = workSpace; - U32 *const Counting2 = Counting1 + 256; - U32 *const Counting3 = Counting2 + 256; - U32 *const Counting4 = Counting3 + 256; - - memset(Counting1, 0, 4 * 256 * sizeof(unsigned)); - - /* safety checks */ - if (!sourceSize) { - memset(count, 0, maxSymbolValue + 1); - *maxSymbolValuePtr = 0; - return 0; - } - if (!maxSymbolValue) - maxSymbolValue = 255; /* 0 == default */ - - /* by stripes of 16 bytes */ - { - U32 cached = ZSTD_read32(ip); - ip += 4; - while (ip < iend - 15) { - U32 c = cached; - cached = ZSTD_read32(ip); - ip += 4; - Counting1[(BYTE)c]++; - Counting2[(BYTE)(c >> 8)]++; - Counting3[(BYTE)(c >> 16)]++; - Counting4[c >> 24]++; - c = cached; - cached = ZSTD_read32(ip); - ip += 4; - Counting1[(BYTE)c]++; - Counting2[(BYTE)(c >> 8)]++; - Counting3[(BYTE)(c >> 16)]++; - Counting4[c >> 24]++; - c = cached; - cached = ZSTD_read32(ip); - ip += 4; - Counting1[(BYTE)c]++; - Counting2[(BYTE)(c >> 8)]++; - Counting3[(BYTE)(c >> 16)]++; - Counting4[c >> 24]++; - c = cached; - cached = ZSTD_read32(ip); - ip += 4; - Counting1[(BYTE)c]++; - Counting2[(BYTE)(c >> 8)]++; - Counting3[(BYTE)(c >> 16)]++; - Counting4[c >> 24]++; - } - ip -= 4; - } - - /* finish last symbols */ - while (ip < iend) - Counting1[*ip++]++; - - if (checkMax) { /* verify stats will fit into destination table */ - U32 s; - for (s = 255; s > maxSymbolValue; s--) { - Counting1[s] += Counting2[s] + Counting3[s] + Counting4[s]; - if (Counting1[s]) - return ERROR(maxSymbolValue_tooSmall); - } - } - - { - U32 s; - for (s = 0; s <= maxSymbolValue; s++) { - count[s] = Counting1[s] + Counting2[s] + Counting3[s] + Counting4[s]; - if (count[s] > max) - max = count[s]; - } - } - - while (!count[maxSymbolValue]) - maxSymbolValue--; - *maxSymbolValuePtr = maxSymbolValue; - return (size_t)max; -} - -/* FSE_countFast_wksp() : - * Same as FSE_countFast(), but using an externally provided scratch buffer. - * `workSpace` size must be table of >= `1024` unsigned */ -size_t FSE_countFast_wksp(unsigned *count, unsigned *maxSymbolValuePtr, const void *source, size_t sourceSize, unsigned *workSpace) -{ - if (sourceSize < 1500) - return FSE_count_simple(count, maxSymbolValuePtr, source, sourceSize); - return FSE_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 0, workSpace); -} - -/* FSE_count_wksp() : - * Same as FSE_count(), but using an externally provided scratch buffer. - * `workSpace` size must be table of >= `1024` unsigned */ -size_t FSE_count_wksp(unsigned *count, unsigned *maxSymbolValuePtr, const void *source, size_t sourceSize, unsigned *workSpace) -{ - if (*maxSymbolValuePtr < 255) - return FSE_count_parallel_wksp(count, maxSymbolValuePtr, source, sourceSize, 1, workSpace); - *maxSymbolValuePtr = 255; - return FSE_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, workSpace); -} - -/*-************************************************************** -* FSE Compression Code -****************************************************************/ -/*! FSE_sizeof_CTable() : - FSE_CTable is a variable size structure which contains : - `U16 tableLog;` - `U16 maxSymbolValue;` - `U16 nextStateNumber[1 << tableLog];` // This size is variable - `FSE_symbolCompressionTransform symbolTT[maxSymbolValue+1];` // This size is variable -Allocation is manual (C standard does not support variable-size structures). -*/ -size_t FSE_sizeof_CTable(unsigned maxSymbolValue, unsigned tableLog) -{ - if (tableLog > FSE_MAX_TABLELOG) - return ERROR(tableLog_tooLarge); - return FSE_CTABLE_SIZE_U32(tableLog, maxSymbolValue) * sizeof(U32); -} - -/* provides the minimum logSize to safely represent a distribution */ -static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue) -{ - U32 minBitsSrc = BIT_highbit32((U32)(srcSize - 1)) + 1; - U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2; - U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols; - return minBits; -} - -unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus) -{ - U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus; - U32 tableLog = maxTableLog; - U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue); - if (tableLog == 0) - tableLog = FSE_DEFAULT_TABLELOG; - if (maxBitsSrc < tableLog) - tableLog = maxBitsSrc; /* Accuracy can be reduced */ - if (minBits > tableLog) - tableLog = minBits; /* Need a minimum to safely represent all symbol values */ - if (tableLog < FSE_MIN_TABLELOG) - tableLog = FSE_MIN_TABLELOG; - if (tableLog > FSE_MAX_TABLELOG) - tableLog = FSE_MAX_TABLELOG; - return tableLog; -} - -unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue) -{ - return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 2); -} - -/* Secondary normalization method. - To be used when primary method fails. */ - -static size_t FSE_normalizeM2(short *norm, U32 tableLog, const unsigned *count, size_t total, U32 maxSymbolValue) -{ - short const NOT_YET_ASSIGNED = -2; - U32 s; - U32 distributed = 0; - U32 ToDistribute; - - /* Init */ - U32 const lowThreshold = (U32)(total >> tableLog); - U32 lowOne = (U32)((total * 3) >> (tableLog + 1)); - - for (s = 0; s <= maxSymbolValue; s++) { - if (count[s] == 0) { - norm[s] = 0; - continue; - } - if (count[s] <= lowThreshold) { - norm[s] = -1; - distributed++; - total -= count[s]; - continue; - } - if (count[s] <= lowOne) { - norm[s] = 1; - distributed++; - total -= count[s]; - continue; - } - - norm[s] = NOT_YET_ASSIGNED; - } - ToDistribute = (1 << tableLog) - distributed; - - if ((total / ToDistribute) > lowOne) { - /* risk of rounding to zero */ - lowOne = (U32)((total * 3) / (ToDistribute * 2)); - for (s = 0; s <= maxSymbolValue; s++) { - if ((norm[s] == NOT_YET_ASSIGNED) && (count[s] <= lowOne)) { - norm[s] = 1; - distributed++; - total -= count[s]; - continue; - } - } - ToDistribute = (1 << tableLog) - distributed; - } - - if (distributed == maxSymbolValue + 1) { - /* all values are pretty poor; - probably incompressible data (should have already been detected); - find max, then give all remaining points to max */ - U32 maxV = 0, maxC = 0; - for (s = 0; s <= maxSymbolValue; s++) - if (count[s] > maxC) - maxV = s, maxC = count[s]; - norm[maxV] += (short)ToDistribute; - return 0; - } - - if (total == 0) { - /* all of the symbols were low enough for the lowOne or lowThreshold */ - for (s = 0; ToDistribute > 0; s = (s + 1) % (maxSymbolValue + 1)) - if (norm[s] > 0) - ToDistribute--, norm[s]++; - return 0; - } - - { - U64 const vStepLog = 62 - tableLog; - U64 const mid = (1ULL << (vStepLog - 1)) - 1; - U64 const rStep = div_u64((((U64)1 << vStepLog) * ToDistribute) + mid, (U32)total); /* scale on remaining */ - U64 tmpTotal = mid; - for (s = 0; s <= maxSymbolValue; s++) { - if (norm[s] == NOT_YET_ASSIGNED) { - U64 const end = tmpTotal + (count[s] * rStep); - U32 const sStart = (U32)(tmpTotal >> vStepLog); - U32 const sEnd = (U32)(end >> vStepLog); - U32 const weight = sEnd - sStart; - if (weight < 1) - return ERROR(GENERIC); - norm[s] = (short)weight; - tmpTotal = end; - } - } - } - - return 0; -} - -size_t FSE_normalizeCount(short *normalizedCounter, unsigned tableLog, const unsigned *count, size_t total, unsigned maxSymbolValue) -{ - /* Sanity checks */ - if (tableLog == 0) - tableLog = FSE_DEFAULT_TABLELOG; - if (tableLog < FSE_MIN_TABLELOG) - return ERROR(GENERIC); /* Unsupported size */ - if (tableLog > FSE_MAX_TABLELOG) - return ERROR(tableLog_tooLarge); /* Unsupported size */ - if (tableLog < FSE_minTableLog(total, maxSymbolValue)) - return ERROR(GENERIC); /* Too small tableLog, compression potentially impossible */ - - { - U32 const rtbTable[] = {0, 473195, 504333, 520860, 550000, 700000, 750000, 830000}; - U64 const scale = 62 - tableLog; - U64 const step = div_u64((U64)1 << 62, (U32)total); /* <== here, one division ! */ - U64 const vStep = 1ULL << (scale - 20); - int stillToDistribute = 1 << tableLog; - unsigned s; - unsigned largest = 0; - short largestP = 0; - U32 lowThreshold = (U32)(total >> tableLog); - - for (s = 0; s <= maxSymbolValue; s++) { - if (count[s] == total) - return 0; /* rle special case */ - if (count[s] == 0) { - normalizedCounter[s] = 0; - continue; - } - if (count[s] <= lowThreshold) { - normalizedCounter[s] = -1; - stillToDistribute--; - } else { - short proba = (short)((count[s] * step) >> scale); - if (proba < 8) { - U64 restToBeat = vStep * rtbTable[proba]; - proba += (count[s] * step) - ((U64)proba << scale) > restToBeat; - } - if (proba > largestP) - largestP = proba, largest = s; - normalizedCounter[s] = proba; - stillToDistribute -= proba; - } - } - if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) { - /* corner case, need another normalization method */ - size_t const errorCode = FSE_normalizeM2(normalizedCounter, tableLog, count, total, maxSymbolValue); - if (FSE_isError(errorCode)) - return errorCode; - } else - normalizedCounter[largest] += (short)stillToDistribute; - } - - return tableLog; -} - -/* fake FSE_CTable, for raw (uncompressed) input */ -size_t FSE_buildCTable_raw(FSE_CTable *ct, unsigned nbBits) -{ - const unsigned tableSize = 1 << nbBits; - const unsigned tableMask = tableSize - 1; - const unsigned maxSymbolValue = tableMask; - void *const ptr = ct; - U16 *const tableU16 = ((U16 *)ptr) + 2; - void *const FSCT = ((U32 *)ptr) + 1 /* header */ + (tableSize >> 1); /* assumption : tableLog >= 1 */ - FSE_symbolCompressionTransform *const symbolTT = (FSE_symbolCompressionTransform *)(FSCT); - unsigned s; - - /* Sanity checks */ - if (nbBits < 1) - return ERROR(GENERIC); /* min size */ - - /* header */ - tableU16[-2] = (U16)nbBits; - tableU16[-1] = (U16)maxSymbolValue; - - /* Build table */ - for (s = 0; s < tableSize; s++) - tableU16[s] = (U16)(tableSize + s); - - /* Build Symbol Transformation Table */ - { - const U32 deltaNbBits = (nbBits << 16) - (1 << nbBits); - for (s = 0; s <= maxSymbolValue; s++) { - symbolTT[s].deltaNbBits = deltaNbBits; - symbolTT[s].deltaFindState = s - 1; - } - } - - return 0; -} - -/* fake FSE_CTable, for rle input (always same symbol) */ -size_t FSE_buildCTable_rle(FSE_CTable *ct, BYTE symbolValue) -{ - void *ptr = ct; - U16 *tableU16 = ((U16 *)ptr) + 2; - void *FSCTptr = (U32 *)ptr + 2; - FSE_symbolCompressionTransform *symbolTT = (FSE_symbolCompressionTransform *)FSCTptr; - - /* header */ - tableU16[-2] = (U16)0; - tableU16[-1] = (U16)symbolValue; - - /* Build table */ - tableU16[0] = 0; - tableU16[1] = 0; /* just in case */ - - /* Build Symbol Transformation Table */ - symbolTT[symbolValue].deltaNbBits = 0; - symbolTT[symbolValue].deltaFindState = 0; - - return 0; -} - -static size_t FSE_compress_usingCTable_generic(void *dst, size_t dstSize, const void *src, size_t srcSize, const FSE_CTable *ct, const unsigned fast) -{ - const BYTE *const istart = (const BYTE *)src; - const BYTE *const iend = istart + srcSize; - const BYTE *ip = iend; - - BIT_CStream_t bitC; - FSE_CState_t CState1, CState2; - - /* init */ - if (srcSize <= 2) - return 0; - { - size_t const initError = BIT_initCStream(&bitC, dst, dstSize); - if (FSE_isError(initError)) - return 0; /* not enough space available to write a bitstream */ - } - -#define FSE_FLUSHBITS(s) (fast ? BIT_flushBitsFast(s) : BIT_flushBits(s)) - - if (srcSize & 1) { - FSE_initCState2(&CState1, ct, *--ip); - FSE_initCState2(&CState2, ct, *--ip); - FSE_encodeSymbol(&bitC, &CState1, *--ip); - FSE_FLUSHBITS(&bitC); - } else { - FSE_initCState2(&CState2, ct, *--ip); - FSE_initCState2(&CState1, ct, *--ip); - } - - /* join to mod 4 */ - srcSize -= 2; - if ((sizeof(bitC.bitContainer) * 8 > FSE_MAX_TABLELOG * 4 + 7) && (srcSize & 2)) { /* test bit 2 */ - FSE_encodeSymbol(&bitC, &CState2, *--ip); - FSE_encodeSymbol(&bitC, &CState1, *--ip); - FSE_FLUSHBITS(&bitC); - } - - /* 2 or 4 encoding per loop */ - while (ip > istart) { - - FSE_encodeSymbol(&bitC, &CState2, *--ip); - - if (sizeof(bitC.bitContainer) * 8 < FSE_MAX_TABLELOG * 2 + 7) /* this test must be static */ - FSE_FLUSHBITS(&bitC); - - FSE_encodeSymbol(&bitC, &CState1, *--ip); - - if (sizeof(bitC.bitContainer) * 8 > FSE_MAX_TABLELOG * 4 + 7) { /* this test must be static */ - FSE_encodeSymbol(&bitC, &CState2, *--ip); - FSE_encodeSymbol(&bitC, &CState1, *--ip); - } - - FSE_FLUSHBITS(&bitC); - } - - FSE_flushCState(&bitC, &CState2); - FSE_flushCState(&bitC, &CState1); - return BIT_closeCStream(&bitC); -} - -size_t FSE_compress_usingCTable(void *dst, size_t dstSize, const void *src, size_t srcSize, const FSE_CTable *ct) -{ - unsigned const fast = (dstSize >= FSE_BLOCKBOUND(srcSize)); - - if (fast) - return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 1); - else - return FSE_compress_usingCTable_generic(dst, dstSize, src, srcSize, ct, 0); -} - -size_t FSE_compressBound(size_t size) { return FSE_COMPRESSBOUND(size); } |