示例#1
0
size_t HUF_compressWeights (void* dst, size_t dstSize, const void* weightTable, size_t wtSize)
{
    BYTE* const ostart = (BYTE*) dst;
    BYTE* op = ostart;
    BYTE* const oend = ostart + dstSize;

    U32 maxSymbolValue = HUF_TABLELOG_MAX;
    U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;

    FSE_CTable CTable[FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX)];
    BYTE scratchBuffer[1<<MAX_FSE_TABLELOG_FOR_HUFF_HEADER];

    U32 count[HUF_TABLELOG_MAX+1];
    S16 norm[HUF_TABLELOG_MAX+1];

    /* init conditions */
    if (wtSize <= 1) return 0;  /* Not compressible */

    /* Scan input and build symbol stats */
    {   CHECK_V_F(maxCount, FSE_count_simple(count, &maxSymbolValue, weightTable, wtSize) );
        if (maxCount == wtSize) return 1;   /* only a single symbol in src : rle */
        if (maxCount == 1) return 0;         /* each symbol present maximum once => not compressible */
    }

    tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
    CHECK_F( FSE_normalizeCount(norm, tableLog, count, wtSize, maxSymbolValue) );

    /* Write table description header */
    {   CHECK_V_F(hSize, FSE_writeNCount(op, oend-op, norm, maxSymbolValue, tableLog) );
        op += hSize;
    }

    /* Compress */
    CHECK_F( FSE_buildCTable_wksp(CTable, norm, maxSymbolValue, tableLog, scratchBuffer, sizeof(scratchBuffer)) );
    {   CHECK_V_F(cSize, FSE_compress_usingCTable(op, oend - op, weightTable, wtSize, CTable) );
        if (cSize == 0) return 0;   /* not enough space for compressed data */
        op += cSize;
    }

    return op-ostart;
}
示例#2
0
size_t HUF_compressWeights_wksp(void *dst, size_t dstSize, const void *weightTable, size_t wtSize, void *workspace, size_t workspaceSize)
{
	BYTE *const ostart = (BYTE *)dst;
	BYTE *op = ostart;
	BYTE *const oend = ostart + dstSize;

	U32 maxSymbolValue = HUF_TABLELOG_MAX;
	U32 tableLog = MAX_FSE_TABLELOG_FOR_HUFF_HEADER;

	FSE_CTable *CTable;
	U32 *count;
	S16 *norm;
	size_t spaceUsed32 = 0;

	HUF_STATIC_ASSERT(sizeof(FSE_CTable) == sizeof(U32));

	CTable = (FSE_CTable *)((U32 *)workspace + spaceUsed32);
	spaceUsed32 += FSE_CTABLE_SIZE_U32(MAX_FSE_TABLELOG_FOR_HUFF_HEADER, HUF_TABLELOG_MAX);
	count = (U32 *)workspace + spaceUsed32;
	spaceUsed32 += HUF_TABLELOG_MAX + 1;
	norm = (S16 *)((U32 *)workspace + spaceUsed32);
	spaceUsed32 += ALIGN(sizeof(S16) * (HUF_TABLELOG_MAX + 1), sizeof(U32)) >> 2;

	if ((spaceUsed32 << 2) > workspaceSize)
		return ERROR(tableLog_tooLarge);
	workspace = (U32 *)workspace + spaceUsed32;
	workspaceSize -= (spaceUsed32 << 2);

	/* init conditions */
	if (wtSize <= 1)
		return 0; /* Not compressible */

	/* Scan input and build symbol stats */
	{
		CHECK_V_F(maxCount, FSE_count_simple(count, &maxSymbolValue, weightTable, wtSize));
		if (maxCount == wtSize)
			return 1; /* only a single symbol in src : rle */
		if (maxCount == 1)
			return 0; /* each symbol present maximum once => not compressible */
	}

	tableLog = FSE_optimalTableLog(tableLog, wtSize, maxSymbolValue);
	CHECK_F(FSE_normalizeCount(norm, tableLog, count, wtSize, maxSymbolValue));

	/* Write table description header */
	{
		CHECK_V_F(hSize, FSE_writeNCount(op, oend - op, norm, maxSymbolValue, tableLog));
		op += hSize;
	}

	/* Compress */
	CHECK_F(FSE_buildCTable_wksp(CTable, norm, maxSymbolValue, tableLog, workspace, workspaceSize));
	{
		CHECK_V_F(cSize, FSE_compress_usingCTable(op, oend - op, weightTable, wtSize, CTable));
		if (cSize == 0)
			return 0; /* not enough space for compressed data */
		op += cSize;
	}

	return op - ostart;
}