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Diffstat (limited to 'lib/zstd/common/fse_decompress.c')
-rw-r--r--lib/zstd/common/fse_decompress.c132
1 files changed, 29 insertions, 103 deletions
diff --git a/lib/zstd/common/fse_decompress.c b/lib/zstd/common/fse_decompress.c
index 8dcb8ca39767..15081d8dc607 100644
--- a/lib/zstd/common/fse_decompress.c
+++ b/lib/zstd/common/fse_decompress.c
@@ -1,6 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/* ******************************************************************
* FSE : Finite State Entropy decoder
- * Copyright (c) Yann Collet, Facebook, Inc.
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
*
* You can contact the author at :
* - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
@@ -22,8 +23,8 @@
#define FSE_STATIC_LINKING_ONLY
#include "fse.h"
#include "error_private.h"
-#define ZSTD_DEPS_NEED_MALLOC
-#include "zstd_deps.h"
+#include "zstd_deps.h" /* ZSTD_memcpy */
+#include "bits.h" /* ZSTD_highbit32 */
/* **************************************************************
@@ -55,19 +56,6 @@
#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)
-
-/* Function templates */
-FSE_DTable* FSE_createDTable (unsigned tableLog)
-{
- if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX;
- return (FSE_DTable*)ZSTD_malloc( FSE_DTABLE_SIZE_U32(tableLog) * sizeof (U32) );
-}
-
-void FSE_freeDTable (FSE_DTable* dt)
-{
- ZSTD_free(dt);
-}
-
static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize)
{
void* const tdPtr = dt+1; /* because *dt is unsigned, 32-bits aligned on 32-bits */
@@ -96,7 +84,7 @@ static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCo
symbolNext[s] = 1;
} else {
if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
- symbolNext[s] = normalizedCounter[s];
+ symbolNext[s] = (U16)normalizedCounter[s];
} } }
ZSTD_memcpy(dt, &DTableH, sizeof(DTableH));
}
@@ -111,8 +99,7 @@ static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCo
* all symbols have counts <= 8. We ensure we have 8 bytes at the end of
* our buffer to handle the over-write.
*/
- {
- U64 const add = 0x0101010101010101ull;
+ { U64 const add = 0x0101010101010101ull;
size_t pos = 0;
U64 sv = 0;
U32 s;
@@ -123,14 +110,13 @@ static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCo
for (i = 8; i < n; i += 8) {
MEM_write64(spread + pos + i, sv);
}
- pos += n;
- }
- }
+ pos += (size_t)n;
+ } }
/* Now we spread those positions across the table.
- * The benefit of doing it in two stages is that we avoid the the
+ * The benefit of doing it in two stages is that we avoid the
* variable size inner loop, which caused lots of branch misses.
* Now we can run through all the positions without any branch misses.
- * We unroll the loop twice, since that is what emperically worked best.
+ * We unroll the loop twice, since that is what empirically worked best.
*/
{
size_t position = 0;
@@ -166,7 +152,7 @@ static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCo
for (u=0; u<tableSize; u++) {
FSE_FUNCTION_TYPE const symbol = (FSE_FUNCTION_TYPE)(tableDecode[u].symbol);
U32 const nextState = symbolNext[symbol]++;
- tableDecode[u].nbBits = (BYTE) (tableLog - BIT_highbit32(nextState) );
+ tableDecode[u].nbBits = (BYTE) (tableLog - ZSTD_highbit32(nextState) );
tableDecode[u].newState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
} }
@@ -184,49 +170,6 @@ size_t FSE_buildDTable_wksp(FSE_DTable* dt, const short* normalizedCounter, unsi
/*-*******************************************************
* Decompression (Byte symbols)
*********************************************************/
-size_t FSE_buildDTable_rle (FSE_DTable* dt, BYTE symbolValue)
-{
- void* ptr = dt;
- FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
- void* dPtr = dt + 1;
- FSE_decode_t* const cell = (FSE_decode_t*)dPtr;
-
- DTableH->tableLog = 0;
- DTableH->fastMode = 0;
-
- cell->newState = 0;
- cell->symbol = symbolValue;
- cell->nbBits = 0;
-
- return 0;
-}
-
-
-size_t FSE_buildDTable_raw (FSE_DTable* dt, unsigned nbBits)
-{
- void* ptr = dt;
- FSE_DTableHeader* const DTableH = (FSE_DTableHeader*)ptr;
- void* dPtr = dt + 1;
- FSE_decode_t* const dinfo = (FSE_decode_t*)dPtr;
- const unsigned tableSize = 1 << nbBits;
- const unsigned tableMask = tableSize - 1;
- const unsigned maxSV1 = tableMask+1;
- unsigned s;
-
- /* Sanity checks */
- if (nbBits < 1) return ERROR(GENERIC); /* min size */
-
- /* Build Decoding Table */
- DTableH->tableLog = (U16)nbBits;
- DTableH->fastMode = 1;
- for (s=0; s<maxSV1; s++) {
- dinfo[s].newState = 0;
- dinfo[s].symbol = (BYTE)s;
- dinfo[s].nbBits = (BYTE)nbBits;
- }
-
- return 0;
-}
FORCE_INLINE_TEMPLATE size_t FSE_decompress_usingDTable_generic(
void* dst, size_t maxDstSize,
@@ -248,6 +191,8 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_usingDTable_generic(
FSE_initDState(&state1, &bitD, dt);
FSE_initDState(&state2, &bitD, dt);
+ RETURN_ERROR_IF(BIT_reloadDStream(&bitD)==BIT_DStream_overflow, corruption_detected, "");
+
#define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)
/* 4 symbols per loop */
@@ -287,32 +232,12 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_usingDTable_generic(
break;
} }
- return op-ostart;
-}
-
-
-size_t FSE_decompress_usingDTable(void* dst, size_t originalSize,
- const void* cSrc, size_t cSrcSize,
- const FSE_DTable* dt)
-{
- const void* ptr = dt;
- const FSE_DTableHeader* DTableH = (const FSE_DTableHeader*)ptr;
- const U32 fastMode = DTableH->fastMode;
-
- /* select fast mode (static) */
- if (fastMode) return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 1);
- return FSE_decompress_usingDTable_generic(dst, originalSize, cSrc, cSrcSize, dt, 0);
-}
-
-
-size_t FSE_decompress_wksp(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, unsigned maxLog, void* workSpace, size_t wkspSize)
-{
- return FSE_decompress_wksp_bmi2(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize, /* bmi2 */ 0);
+ assert(op >= ostart);
+ return (size_t)(op-ostart);
}
typedef struct {
short ncount[FSE_MAX_SYMBOL_VALUE + 1];
- FSE_DTable dtable[]; /* Dynamically sized */
} FSE_DecompressWksp;
@@ -327,13 +252,18 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
unsigned tableLog;
unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
FSE_DecompressWksp* const wksp = (FSE_DecompressWksp*)workSpace;
+ size_t const dtablePos = sizeof(FSE_DecompressWksp) / sizeof(FSE_DTable);
+ FSE_DTable* const dtable = (FSE_DTable*)workSpace + dtablePos;
- DEBUG_STATIC_ASSERT((FSE_MAX_SYMBOL_VALUE + 1) % 2 == 0);
+ FSE_STATIC_ASSERT((FSE_MAX_SYMBOL_VALUE + 1) % 2 == 0);
if (wkspSize < sizeof(*wksp)) return ERROR(GENERIC);
+ /* correct offset to dtable depends on this property */
+ FSE_STATIC_ASSERT(sizeof(FSE_DecompressWksp) % sizeof(FSE_DTable) == 0);
+
/* normal FSE decoding mode */
- {
- size_t const NCountLength = FSE_readNCount_bmi2(wksp->ncount, &maxSymbolValue, &tableLog, istart, cSrcSize, bmi2);
+ { size_t const NCountLength =
+ FSE_readNCount_bmi2(wksp->ncount, &maxSymbolValue, &tableLog, istart, cSrcSize, bmi2);
if (FSE_isError(NCountLength)) return NCountLength;
if (tableLog > maxLog) return ERROR(tableLog_tooLarge);
assert(NCountLength <= cSrcSize);
@@ -342,19 +272,20 @@ FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
}
if (FSE_DECOMPRESS_WKSP_SIZE(tableLog, maxSymbolValue) > wkspSize) return ERROR(tableLog_tooLarge);
- workSpace = wksp->dtable + FSE_DTABLE_SIZE_U32(tableLog);
+ assert(sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog) <= wkspSize);
+ workSpace = (BYTE*)workSpace + sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog);
wkspSize -= sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog);
- CHECK_F( FSE_buildDTable_internal(wksp->dtable, wksp->ncount, maxSymbolValue, tableLog, workSpace, wkspSize) );
+ CHECK_F( FSE_buildDTable_internal(dtable, wksp->ncount, maxSymbolValue, tableLog, workSpace, wkspSize) );
{
- const void* ptr = wksp->dtable;
+ const void* ptr = dtable;
const FSE_DTableHeader* DTableH = (const FSE_DTableHeader*)ptr;
const U32 fastMode = DTableH->fastMode;
/* select fast mode (static) */
- if (fastMode) return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, wksp->dtable, 1);
- return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, wksp->dtable, 0);
+ if (fastMode) return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, dtable, 1);
+ return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, dtable, 0);
}
}
@@ -382,9 +313,4 @@ size_t FSE_decompress_wksp_bmi2(void* dst, size_t dstCapacity, const void* cSrc,
return FSE_decompress_wksp_body_default(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize);
}
-
-typedef FSE_DTable DTable_max_t[FSE_DTABLE_SIZE_U32(FSE_MAX_TABLELOG)];
-
-
-
#endif /* FSE_COMMONDEFS_ONLY */
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-31 08:57:25 +0000