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fileio.c does no longer need ZSTD_LEGACY_SUPPORT, and does no longer depend on zstd_legacy.h 

Added : ZSTD_isFrame() in experimental section
dev
Yann Collet 2016-11-02 17:30:49 -07:00
parent f3f13211ae
commit 179b19776f
3 changed files with 37 additions and 31 deletions
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19
lib/decompress/zstd_decompress.c
View File

@ -193,7 +193,24 @@ static void ZSTD_refDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
* Decompression section
***************************************************************/
/* See compression format details in : doc/zstd_compression_format.md */
/*! ZSTD_isFrame() :
* Tells if the content of `buffer` starts with a valid Frame Identifier.
* Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
* Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
* Note 3 : Skippable Frame Identifiers are considered valid. */
unsigned ZSTD_isFrame(const void* buffer, size_t size)
{
if (size < 4) return 0;
{ U32 const magic = MEM_readLE32(buffer);
if (magic == ZSTD_MAGICNUMBER) return 1;
if ((magic & 0xFFFFFFF0U) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
}
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
if (ZSTD_isLegacy(buffer, size)) return 1;
#endif
return 0;
}
/** ZSTD_frameHeaderSize() :
* srcSize must be >= ZSTD_frameHeaderSize_prefix.

7
lib/zstd.h
View File

@ -433,6 +433,13 @@ ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
/*--- Advanced decompression functions ---*/
/*! ZSTD_isFrame() :
* Tells if the content of `buffer` starts with a valid Frame Identifier.
* Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
* Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
* Note 3 : Skippable Frame Identifiers are considered valid. */
ZSTDLIB_API unsigned ZSTD_isFrame(const void* buffer, size_t size);
/*! ZSTD_estimateDCtxSize() :
* Gives the potential amount of memory allocated to create a ZSTD_DCtx */
ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void);

42
programs/fileio.c
View File

@ -8,16 +8,6 @@
*/
/* *************************************
* Tuning options
***************************************/
#ifndef ZSTD_LEGACY_SUPPORT
/* LEGACY_SUPPORT :
* decompressor can decode older formats (starting from zstd 0.1+) */
# define ZSTD_LEGACY_SUPPORT 1
#endif
/* *************************************
* Compiler Options
***************************************/
@ -29,6 +19,7 @@
# define _POSIX_SOURCE 1 /* disable %llu warnings with MinGW on Windows */
#endif
/*-*************************************
* Includes
***************************************/
@ -44,10 +35,6 @@
#define ZSTD_STATIC_LINKING_ONLY /* ZSTD_magicNumber, ZSTD_frameHeaderSize_max */
#include "zstd.h"
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
# include "zstd_legacy.h" /* ZSTD_isLegacy */
#endif
/*-*************************************
* OS-specific Includes
@ -634,7 +621,7 @@ unsigned long long FIO_decompressFrame(dRess_t ress,
@return : 0 (no error) */
static unsigned FIO_passThrough(FILE* foutput, FILE* finput, void* buffer, size_t bufferSize)
{
size_t const blockSize = MIN (64 KB, bufferSize);
size_t const blockSize = MIN(64 KB, bufferSize);
size_t readFromInput = 1;
unsigned storedSkips = 0;
@ -682,21 +669,16 @@ static int FIO_decompressSrcFile(dRess_t ress, const char* srcFileName)
}
readSomething = 1; /* there is at least >= 4 bytes in srcFile */
if (sizeCheck != toRead) { DISPLAY("zstd: %s: unknown header \n", srcFileName); fclose(srcFile); return 1; } /* srcFileName is empty */
{ U32 const magic = MEM_readLE32(ress.srcBuffer);
if (((magic & 0xFFFFFFF0U) != ZSTD_MAGIC_SKIPPABLE_START) & (magic != ZSTD_MAGICNUMBER)
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
& (!ZSTD_isLegacy(ress.srcBuffer, toRead))
#endif
) {
if ((g_overwrite) && !strcmp (srcFileName, stdinmark)) { /* pass-through mode */
unsigned const result = FIO_passThrough(dstFile, srcFile, ress.srcBuffer, ress.srcBufferSize);
if (fclose(srcFile)) EXM_THROW(32, "zstd: %s close error", srcFileName); /* error should never happen */
return result;
} else {
DISPLAYLEVEL(1, "zstd: %s: not in zstd format \n", srcFileName);
fclose(srcFile);
return 1;
} } }
if (!ZSTD_isFrame(ress.srcBuffer, toRead)) {
if ((g_overwrite) && !strcmp (srcFileName, stdinmark)) { /* pass-through mode */
unsigned const result = FIO_passThrough(dstFile, srcFile, ress.srcBuffer, ress.srcBufferSize);
if (fclose(srcFile)) EXM_THROW(32, "zstd: %s close error", srcFileName); /* error should never happen */
return result;
} else {
DISPLAYLEVEL(1, "zstd: %s: not in zstd format \n", srcFileName);
fclose(srcFile);
return 1;
} }
filesize += FIO_decompressFrame(ress, dstFile, srcFile, toRead);
}