contrib/zstd/lib/compress/fse_compress.c in extzstd-0.2 vs contrib/zstd/lib/compress/fse_compress.c in extzstd-0.3
- old
+ new
@@ -1,8 +1,8 @@
/* ******************************************************************
FSE : Finite State Entropy encoder
- Copyright (C) 2013-2015, Yann Collet.
+ Copyright (C) 2013-present, 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
@@ -35,23 +35,24 @@
/* **************************************************************
* Includes
****************************************************************/
#include <stdlib.h> /* malloc, free, qsort */
#include <string.h> /* memcpy, memset */
-#include <stdio.h> /* printf (debug) */
-#include "bitstream.h"
#include "compiler.h"
+#include "mem.h" /* U32, U16, etc. */
+#include "debug.h" /* assert, DEBUGLOG */
+#include "hist.h" /* HIST_count_wksp */
+#include "bitstream.h"
#define FSE_STATIC_LINKING_ONLY
#include "fse.h"
#include "error_private.h"
/* **************************************************************
* Error Management
****************************************************************/
#define FSE_isError ERR_isError
-#define FSE_STATIC_ASSERT(c) { enum { FSE_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
/* **************************************************************
* Templates
****************************************************************/
@@ -80,11 +81,13 @@
/* 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 wkspSize)
+size_t FSE_buildCTable_wksp(FSE_CTable* ct,
+ const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog,
+ void* workSpace, size_t wkspSize)
{
U32 const tableSize = 1 << tableLog;
U32 const tableMask = tableSize - 1;
void* const ptr = ct;
U16* const tableU16 = ( (U16*) ptr) + 2;
@@ -98,18 +101,23 @@
/* CTable header */
if (((size_t)1 << tableLog) * sizeof(FSE_FUNCTION_TYPE) > wkspSize) return ERROR(tableLog_tooLarge);
tableU16[-2] = (U16) tableLog;
tableU16[-1] = (U16) maxSymbolValue;
+ assert(tableLog < 16); /* required for threshold strategy to work */
/* For explanations on how to distribute symbol values over the table :
- * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */
+ * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */
+ #ifdef __clang_analyzer__
+ memset(tableSymbol, 0, sizeof(*tableSymbol) * tableSize); /* useless initialization, just to keep scan-build happy */
+ #endif
+
/* symbol start positions */
{ U32 u;
cumul[0] = 0;
- for (u=1; u<=maxSymbolValue+1; u++) {
+ 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];
@@ -119,18 +127,20 @@
/* Spread symbols */
{ U32 position = 0;
U32 symbol;
for (symbol=0; symbol<=maxSymbolValue; symbol++) {
- int nbOccurences;
- for (nbOccurences=0; nbOccurences<normalizedCounter[symbol]; nbOccurences++) {
+ int nbOccurrences;
+ int const freq = normalizedCounter[symbol];
+ for (nbOccurrences=0; nbOccurrences<freq; nbOccurrences++) {
tableSymbol[position] = (FSE_FUNCTION_TYPE)symbol;
position = (position + step) & tableMask;
- while (position > highThreshold) position = (position + step) & tableMask; /* Low proba area */
+ while (position > highThreshold)
+ position = (position + step) & tableMask; /* Low proba area */
} }
- if (position!=0) return ERROR(GENERIC); /* Must have gone through all positions */
+ assert(position==0); /* Must have initialized 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 */
@@ -141,11 +151,14 @@
{ unsigned total = 0;
unsigned s;
for (s=0; s<=maxSymbolValue; s++) {
switch (normalizedCounter[s])
{
- case 0: break;
+ case 0:
+ /* filling nonetheless, for compatibility with FSE_getMaxNbBits() */
+ symbolTT[s].deltaNbBits = ((tableLog+1) << 16) - (1<<tableLog);
+ break;
case -1:
case 1:
symbolTT[s].deltaNbBits = (tableLog << 16) - (1<<tableLog);
symbolTT[s].deltaFindState = total - 1;
@@ -158,10 +171,22 @@
symbolTT[s].deltaNbBits = (maxBitsOut << 16) - minStatePlus;
symbolTT[s].deltaFindState = total - normalizedCounter[s];
total += normalizedCounter[s];
} } } }
+#if 0 /* debug : symbol costs */
+ DEBUGLOG(5, "\n --- table statistics : ");
+ { U32 symbol;
+ for (symbol=0; symbol<=maxSymbolValue; symbol++) {
+ DEBUGLOG(5, "%3u: w=%3i, maxBits=%u, fracBits=%.2f",
+ symbol, normalizedCounter[symbol],
+ FSE_getMaxNbBits(symbolTT, symbol),
+ (double)FSE_bitCost(symbolTT, tableLog, symbol, 8) / 256);
+ }
+ }
+#endif
+
return 0;
}
size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
@@ -172,280 +197,132 @@
#ifndef FSE_COMMONDEFS_ONLY
+
/*-**************************************************************
-* FSE NCount encoding-decoding
+* FSE NCount encoding
****************************************************************/
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)
+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;
+ U32 bitStream = 0;
+ int bitCount = 0;
+ unsigned symbol = 0;
+ unsigned const alphabetSize = maxSymbolValue + 1;
+ int previousIs0 = 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) {
+ while ((symbol < alphabetSize) && (remaining>1)) { /* stops at 1 */
+ if (previousIs0) {
+ unsigned start = symbol;
+ while ((symbol < alphabetSize) && !normalizedCounter[symbol]) symbol++;
+ if (symbol == alphabetSize) break; /* incorrect distribution */
+ while (symbol >= start+24) {
start+=24;
bitStream += 0xFFFFU << bitCount;
- if ((!writeIsSafe) && (out > oend-2)) return ERROR(dstSize_tooSmall); /* Buffer overflow */
+ 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) {
+ while (symbol >= start+3) {
start+=3;
bitStream += 3 << bitCount;
bitCount += 2;
}
- bitStream += (charnum-start) << bitCount;
+ bitStream += (symbol-start) << bitCount;
bitCount += 2;
if (bitCount>16) {
- if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall); /* Buffer overflow */
+ 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;
+ { int count = normalizedCounter[symbol++];
+ 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[ */
+ if (count>=threshold)
+ count += max; /* [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ */
bitStream += count << bitCount;
bitCount += nbBits;
bitCount -= (count<max);
- previous0 = (count==1);
+ previousIs0 = (count==1);
if (remaining<1) return ERROR(GENERIC);
- while (remaining<threshold) nbBits--, threshold>>=1;
+ while (remaining<threshold) { nbBits--; threshold>>=1; }
}
if (bitCount>16) {
- if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall); /* Buffer overflow */
+ 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;
} }
+ if (remaining != 1)
+ return ERROR(GENERIC); /* incorrect normalized distribution */
+ assert(symbol <= alphabetSize);
+
/* flush remaining bitStream */
- if ((!writeIsSafe) && (out > oend - 2)) return ERROR(dstSize_tooSmall); /* Buffer overflow */
+ 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)
+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);
+ return FSE_writeNCount_generic(buffer, bufferSize, normalizedCounter, maxSymbolValue, tableLog, 1 /* write in buffer is safe */);
}
-
/*-**************************************************************
-* 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 = MEM_read32(ip); ip += 4;
- while (ip < iend-15) {
- U32 c = cached; cached = MEM_read32(ip); ip += 4;
- Counting1[(BYTE) c ]++;
- Counting2[(BYTE)(c>>8) ]++;
- Counting3[(BYTE)(c>>16)]++;
- Counting4[ c>>24 ]++;
- c = cached; cached = MEM_read32(ip); ip += 4;
- Counting1[(BYTE) c ]++;
- Counting2[(BYTE)(c>>8) ]++;
- Counting3[(BYTE)(c>>16)]++;
- Counting4[ c>>24 ]++;
- c = cached; cached = MEM_read32(ip); ip += 4;
- Counting1[(BYTE) c ]++;
- Counting2[(BYTE)(c>>8) ]++;
- Counting3[(BYTE)(c>>16)]++;
- Counting4[ c>>24 ]++;
- c = cached; cached = MEM_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);
-}
-
-/* fast variant (unsafe : won't check if src contains values beyond count[] limit) */
-size_t FSE_countFast(unsigned* count, unsigned* maxSymbolValuePtr,
- const void* source, size_t sourceSize)
-{
- unsigned tmpCounters[1024];
- return FSE_countFast_wksp(count, maxSymbolValuePtr, source, sourceSize, tmpCounters);
-}
-
-/* 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);
-}
-
-size_t FSE_count(unsigned* count, unsigned* maxSymbolValuePtr,
- const void* src, size_t srcSize)
-{
- unsigned tmpCounters[1024];
- return FSE_count_wksp(count, maxSymbolValuePtr, src, srcSize, tmpCounters);
-}
-
-
-
-/*-**************************************************************
* 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);
-}
FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog)
{
size_t size;
if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
@@ -456,11 +333,11 @@
void FSE_freeCTable (FSE_CTable* ct) { free(ct); }
/* 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 minBitsSrc = BIT_highbit32((U32)(srcSize)) + 1;
U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2;
U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols;
assert(srcSize > 1); /* Not supported, RLE should be used instead */
return minBits;
}
@@ -519,10 +396,13 @@
norm[s]=NOT_YET_ASSIGNED;
}
ToDistribute = (1 << tableLog) - distributed;
+ if (ToDistribute == 0)
+ return 0;
+
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)) {
@@ -538,19 +418,19 @@
/* 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];
+ 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]++;
+ if (norm[s] > 0) { ToDistribute--; norm[s]++; }
return 0;
}
{ U64 const vStepLog = 62 - tableLog;
U64 const mid = (1ULL << (vStepLog-1)) - 1;
@@ -602,11 +482,11 @@
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;
+ if (proba > largestP) { largestP=proba; largest=s; }
normalizedCounter[s] = proba;
stillToDistribute -= proba;
} }
if (-stillToDistribute >= (normalizedCounter[largest] >> 1)) {
/* corner case, need another normalization method */
@@ -619,15 +499,15 @@
#if 0
{ /* Print Table (debug) */
U32 s;
U32 nTotal = 0;
for (s=0; s<=maxSymbolValue; s++)
- printf("%3i: %4i \n", s, normalizedCounter[s]);
+ RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]);
for (s=0; s<=maxSymbolValue; s++)
nTotal += abs(normalizedCounter[s]);
if (nTotal != (1U<<tableLog))
- printf("Warning !!! Total == %u != %u !!!", nTotal, 1U<<tableLog);
+ RAWLOG(2, "Warning !!! Total == %u != %u !!!", nTotal, 1U<<tableLog);
getchar();
}
#endif
return tableLog;
@@ -776,11 +656,11 @@
{
BYTE* const ostart = (BYTE*) dst;
BYTE* op = ostart;
BYTE* const oend = ostart + dstSize;
- U32 count[FSE_MAX_SYMBOL_VALUE+1];
+ unsigned count[FSE_MAX_SYMBOL_VALUE+1];
S16 norm[FSE_MAX_SYMBOL_VALUE+1];
FSE_CTable* CTable = (FSE_CTable*)workSpace;
size_t const CTableSize = FSE_CTABLE_SIZE_U32(tableLog, maxSymbolValue);
void* scratchBuffer = (void*)(CTable + CTableSize);
size_t const scratchBufferSize = wkspSize - (CTableSize * sizeof(FSE_CTable));
@@ -790,11 +670,11 @@
if (srcSize <= 1) return 0; /* Not compressible */
if (!maxSymbolValue) maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
if (!tableLog) tableLog = FSE_DEFAULT_TABLELOG;
/* Scan input and build symbol stats */
- { CHECK_V_F(maxCount, FSE_count_wksp(count, &maxSymbolValue, src, srcSize, (unsigned*)scratchBuffer) );
+ { CHECK_V_F(maxCount, HIST_count_wksp(count, &maxSymbolValue, src, srcSize, scratchBuffer, scratchBufferSize) );
if (maxCount == srcSize) return 1; /* only a single symbol in src : rle */
if (maxCount == 1) return 0; /* each symbol present maximum once => not compressible */
if (maxCount < (srcSize >> 7)) return 0; /* Heuristic : not compressible enough */
}
@@ -825,10 +705,10 @@
} fseWkspMax_t;
size_t FSE_compress2 (void* dst, size_t dstCapacity, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog)
{
fseWkspMax_t scratchBuffer;
- FSE_STATIC_ASSERT(sizeof(scratchBuffer) >= FSE_WKSP_SIZE_U32(FSE_MAX_TABLELOG, FSE_MAX_SYMBOL_VALUE)); /* compilation failures here means scratchBuffer is not large enough */
+ DEBUG_STATIC_ASSERT(sizeof(scratchBuffer) >= FSE_WKSP_SIZE_U32(FSE_MAX_TABLELOG, FSE_MAX_SYMBOL_VALUE)); /* compilation failures here means scratchBuffer is not large enough */
if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);
return FSE_compress_wksp(dst, dstCapacity, src, srcSize, maxSymbolValue, tableLog, &scratchBuffer, sizeof(scratchBuffer));
}
size_t FSE_compress (void* dst, size_t dstCapacity, const void* src, size_t srcSize)