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/* Lzma86Enc.c -- LZMA + x86 (BCJ) Filter Encoder
2009-08-14 : Igor Pavlov : Public domain */

#include <string.h>

#include "Lzma86.h"

#include "Alloc.h"
#include "Bra.h"
#include "LzmaEnc.h"

#define SZE_OUT_OVERFLOW SZE_DATA_ERROR

static void *SzAlloc(void *p, size_t size) { p = p; return MyAlloc(size); }
static void SzFree(void *p, void *address) { p = p; MyFree(address); }

int Lzma86_Encode(Byte *dest, size_t *destLen, const Byte *src, size_t srcLen,
	int level, UInt32 dictSize, int filterMode)
{
	ISzAlloc g_Alloc = { SzAlloc, SzFree };
	size_t outSize2 = *destLen;
	Byte *filteredStream;
	Bool useFilter;
	int mainResult = SZ_ERROR_OUTPUT_EOF;
	CLzmaEncProps props;
	LzmaEncProps_Init(&props);
	props.level = level;
	props.dictSize = dictSize;

	*destLen = 0;
	if (outSize2 < LZMA86_HEADER_SIZE)
	return SZ_ERROR_OUTPUT_EOF;

	{
	int i;
	UInt64 t = srcLen;
	for (i = 0; i < 8; i++, t >>= 8)
		dest[LZMA86_SIZE_OFFSET + i] = (Byte)t;
	}

	filteredStream = 0;
	useFilter = (filterMode != SZ_FILTER_NO);
	if (useFilter)
	{
	if (srcLen != 0)
	{
		filteredStream = (Byte *)MyAlloc(srcLen);
		if (filteredStream == 0)
		return SZ_ERROR_MEM;
		memcpy(filteredStream, src, srcLen);
	}
	{
		UInt32 x86State;
		x86_Convert_Init(x86State);
		x86_Convert(filteredStream, srcLen, 0, &x86State, 1);
	}
	}

	{
	size_t minSize = 0;
	Bool bestIsFiltered = False;

	/* passes for SZ_FILTER_AUTO:
	    0 - BCJ + LZMA
	    1 - LZMA
	    2 - BCJ + LZMA agaian, if pass 0 (BCJ + LZMA) is better.
	*/
	int numPasses = (filterMode == SZ_FILTER_AUTO) ? 3 : 1;

	int i;
	for (i = 0; i < numPasses; i++)
	{
		size_t outSizeProcessed = outSize2 - LZMA86_HEADER_SIZE;
		size_t outPropsSize = 5;
		SRes curRes;
		Bool curModeIsFiltered = (numPasses > 1 && i == numPasses - 1);
		if (curModeIsFiltered && !bestIsFiltered)
		break;
		if (useFilter && i == 0)
		curModeIsFiltered = True;

		curRes = LzmaEncode(dest + LZMA86_HEADER_SIZE, &outSizeProcessed,
			curModeIsFiltered ? filteredStream : src, srcLen,
			&props, dest + 1, &outPropsSize, 0,
			NULL, &g_Alloc, &g_Alloc);

		if (curRes != SZ_ERROR_OUTPUT_EOF)
		{
		if (curRes != SZ_OK)
		{
			mainResult = curRes;
			break;
		}
		if (outSizeProcessed <= minSize || mainResult != SZ_OK)
		{
			minSize = outSizeProcessed;
			bestIsFiltered = curModeIsFiltered;
			mainResult = SZ_OK;
		}
		}
	}
	dest[0] = (bestIsFiltered ? 1 : 0);
	*destLen = LZMA86_HEADER_SIZE + minSize;
	}
	if (useFilter)
	MyFree(filteredStream);
	return mainResult;
}