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added emphasis on the alignment condition of workspace

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and made it a programming mistake (`assert()`)
rather than a runtime error.
This commit is contained in:
Yann Collet 2020-12-18 15:04:09 -08:00
parent 456ca2aa06
commit a7cb4af573
1 changed files with 6 additions and 5 deletions
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11
lib/compress/huf_compress.c
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@ -736,25 +736,26 @@ typedef struct {
} HUF_compress_tables_t; } HUF_compress_tables_t;
/* HUF_compress_internal() : /* HUF_compress_internal() :
* `workSpace` must a table of at least HUF_WORKSPACE_SIZE_U32 unsigned */ * `workSpace_align4` must be aligned on 4-bytes boundaries,
* and occupies the same space as a table of HUF_WORKSPACE_SIZE_U32 unsigned */
static size_t static size_t
HUF_compress_internal (void* dst, size_t dstSize, HUF_compress_internal (void* dst, size_t dstSize,
const void* src, size_t srcSize, const void* src, size_t srcSize,
unsigned maxSymbolValue, unsigned huffLog, unsigned maxSymbolValue, unsigned huffLog,
HUF_nbStreams_e nbStreams, HUF_nbStreams_e nbStreams,
void* workSpace, size_t wkspSize, void* workSpace_align4, size_t wkspSize,
HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat, HUF_CElt* oldHufTable, HUF_repeat* repeat, int preferRepeat,
const int bmi2) const int bmi2)
{ {
HUF_compress_tables_t* const table = (HUF_compress_tables_t*)workSpace; HUF_compress_tables_t* const table = (HUF_compress_tables_t*)workSpace_align4;
BYTE* const ostart = (BYTE*)dst; BYTE* const ostart = (BYTE*)dst;
BYTE* const oend = ostart + dstSize; BYTE* const oend = ostart + dstSize;
BYTE* op = ostart; BYTE* op = ostart;
HUF_STATIC_ASSERT(sizeof(*table) <= HUF_WORKSPACE_SIZE); HUF_STATIC_ASSERT(sizeof(*table) <= HUF_WORKSPACE_SIZE);
assert(((size_t)workSpace_align4 & 3) == 0); /* must be aligned on 4-bytes boundaries */
/* checks & inits */ /* checks & inits */
if (((size_t)workSpace & 3) != 0) return ERROR(GENERIC); /* must be aligned on 4-bytes boundaries */
if (wkspSize < HUF_WORKSPACE_SIZE) return ERROR(workSpace_tooSmall); if (wkspSize < HUF_WORKSPACE_SIZE) return ERROR(workSpace_tooSmall);
if (!srcSize) return 0; /* Uncompressed */ if (!srcSize) return 0; /* Uncompressed */
if (!dstSize) return 0; /* cannot fit anything within dst budget */ if (!dstSize) return 0; /* cannot fit anything within dst budget */
@ -772,7 +773,7 @@ HUF_compress_internal (void* dst, size_t dstSize,
} }
/* Scan input and build symbol stats */ /* Scan input and build symbol stats */
{ CHECK_V_F(largest, HIST_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, workSpace, wkspSize) ); { CHECK_V_F(largest, HIST_count_wksp (table->count, &maxSymbolValue, (const BYTE*)src, srcSize, workSpace_align4, wkspSize) );
if (largest == srcSize) { *ostart = ((const BYTE*)src)[0]; return 1; } /* single symbol, rle */ 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 */ if (largest <= (srcSize >> 7)+4) return 0; /* heuristic : probably not compressible enough */
} }