sharpetronics/zstd
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created ZSTD_startingInputLength()

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as suggested by @terrelln
This commit is contained in:
Yann Collet 2017-09-26 15:36:14 -07:00
parent 8d1e97ea9c
commit 319c699991
1 changed files with 13 additions and 13 deletions
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26
lib/decompress/zstd_decompress.c
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@ -150,11 +150,19 @@ size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }
static size_t ZSTD_startingInputLength(ZSTD_format_e format)
{
size_t const startingInputLength = (format==ZSTD_f_zstd1_magicless) ?
ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize :
ZSTD_frameHeaderSize_prefix;
ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE);
return startingInputLength;
}
size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
{
dctx->expected = (dctx->format==ZSTD_f_zstd1_magicless) ?
ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize :
ZSTD_frameHeaderSize_prefix;
dctx->expected = ZSTD_startingInputLength(dctx->format);
dctx->stage = ZSTDds_getFrameHeaderSize;
dctx->decodedSize = 0;
dctx->previousDstEnd = NULL;
@ -267,7 +275,6 @@ unsigned ZSTD_isFrame(const void* buffer, size_t size)
return 0;
}
/** ZSTD_frameHeaderSize_internal() :
* srcSize must be large enough to reach header size fields.
* note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
@ -275,12 +282,7 @@ unsigned ZSTD_isFrame(const void* buffer, size_t size)
* or an error code, which can be tested with ZSTD_isError() */
static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
{
size_t const minInputSize = (format==ZSTD_f_zstd1_magicless) ?
ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize :
ZSTD_frameHeaderSize_prefix;
ZSTD_STATIC_ASSERT(ZSTD_FRAMEHEADERSIZE_PREFIX >= ZSTD_FRAMEIDSIZE);
/* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
size_t const minInputSize = ZSTD_startingInputLength(format);
if (srcSize < minInputSize) return ERROR(srcSize_wrong);
{ BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
@ -311,9 +313,7 @@ size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
static size_t ZSTD_getFrameHeader_internal(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
{
const BYTE* ip = (const BYTE*)src;
size_t const minInputSize = (format==ZSTD_f_zstd1_magicless) ?
ZSTD_frameHeaderSize_prefix - ZSTD_frameIdSize :
ZSTD_frameHeaderSize_prefix;
size_t const minInputSize = ZSTD_startingInputLength(format);
/* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );