/* 7zIn.c -- 7z Input functions
2010-10-29 : Igor Pavlov : Public domain */

#include <string.h>

#include "7z.h"
#include "7zCrc.h"
#include "CpuArch.h"

Byte k7zSignature[k7zSignatureSize] = {'7', 'z', 0xBC, 0xAF, 0x27, 0x1C};

#define RINOM(x) { if ((x) == 0) return SZ_ERROR_MEM; }

#define NUM_FOLDER_CODERS_MAX 32
#define NUM_CODER_STREAMS_MAX 32

void SzCoderInfo_Init(CSzCoderInfo *p)
{
	Buf_Init(&p->Props);
}

void SzCoderInfo_Free(CSzCoderInfo *p, ISzAlloc *alloc)
{
	Buf_Free(&p->Props, alloc);
	SzCoderInfo_Init(p);
}

void SzFolder_Init(CSzFolder *p)
{
	p->Coders = 0;
	p->BindPairs = 0;
	p->PackStreams = 0;
	p->UnpackSizes = 0;
	p->NumCoders = 0;
	p->NumBindPairs = 0;
	p->NumPackStreams = 0;
	p->UnpackCRCDefined = 0;
	p->UnpackCRC = 0;
	p->NumUnpackStreams = 0;
}

void SzFolder_Free(CSzFolder *p, ISzAlloc *alloc)
{
	UInt32 i;
	if (p->Coders)
		for (i = 0; i < p->NumCoders; i++)
			SzCoderInfo_Free(&p->Coders[i], alloc);
	IAlloc_Free(alloc, p->Coders);
	IAlloc_Free(alloc, p->BindPairs);
	IAlloc_Free(alloc, p->PackStreams);
	IAlloc_Free(alloc, p->UnpackSizes);
	SzFolder_Init(p);
}

UInt32 SzFolder_GetNumOutStreams(CSzFolder *p)
{
	UInt32 result = 0;
	UInt32 i;
	for (i = 0; i < p->NumCoders; i++)
		result += p->Coders[i].NumOutStreams;
	return result;
}

int SzFolder_FindBindPairForInStream(CSzFolder *p, UInt32 inStreamIndex)
{
	UInt32 i;
	for (i = 0; i < p->NumBindPairs; i++)
		if (p->BindPairs[i].InIndex == inStreamIndex)
			return i;
	return -1;
}


int SzFolder_FindBindPairForOutStream(CSzFolder *p, UInt32 outStreamIndex)
{
	UInt32 i;
	for (i = 0; i < p->NumBindPairs; i++)
		if (p->BindPairs[i].OutIndex == outStreamIndex)
			return i;
	return -1;
}

UInt64 SzFolder_GetUnpackSize(CSzFolder *p)
{
	int i = (int)SzFolder_GetNumOutStreams(p);
	if (i == 0)
		return 0;
	for (i--; i >= 0; i--)
		if (SzFolder_FindBindPairForOutStream(p, i) < 0)
			return p->UnpackSizes[i];
	/* throw 1; */
	return 0;
}

void SzFile_Init(CSzFileItem *p)
{
	p->HasStream = 1;
	p->IsDir = 0;
	p->IsAnti = 0;
	p->CrcDefined = 0;
	p->MTimeDefined = 0;
}

void SzAr_Init(CSzAr *p)
{
	p->PackSizes = 0;
	p->PackCRCsDefined = 0;
	p->PackCRCs = 0;
	p->Folders = 0;
	p->Files = 0;
	p->NumPackStreams = 0;
	p->NumFolders = 0;
	p->NumFiles = 0;
}

void SzAr_Free(CSzAr *p, ISzAlloc *alloc)
{
	UInt32 i;
	if (p->Folders)
		for (i = 0; i < p->NumFolders; i++)
			SzFolder_Free(&p->Folders[i], alloc);

	IAlloc_Free(alloc, p->PackSizes);
	IAlloc_Free(alloc, p->PackCRCsDefined);
	IAlloc_Free(alloc, p->PackCRCs);
	IAlloc_Free(alloc, p->Folders);
	IAlloc_Free(alloc, p->Files);
	SzAr_Init(p);
}


void SzArEx_Init(CSzArEx *p)
{
	SzAr_Init(&p->db);
	p->FolderStartPackStreamIndex = 0;
	p->PackStreamStartPositions = 0;
	p->FolderStartFileIndex = 0;
	p->FileIndexToFolderIndexMap = 0;
	p->FileNameOffsets = 0;
	Buf_Init(&p->FileNames);
}

void SzArEx_Free(CSzArEx *p, ISzAlloc *alloc)
{
	IAlloc_Free(alloc, p->FolderStartPackStreamIndex);
	IAlloc_Free(alloc, p->PackStreamStartPositions);
	IAlloc_Free(alloc, p->FolderStartFileIndex);
	IAlloc_Free(alloc, p->FileIndexToFolderIndexMap);

	IAlloc_Free(alloc, p->FileNameOffsets);
	Buf_Free(&p->FileNames, alloc);

	SzAr_Free(&p->db, alloc);
	SzArEx_Init(p);
}

/*
UInt64 GetFolderPackStreamSize(int folderIndex, int streamIndex) const
{
return PackSizes[FolderStartPackStreamIndex[folderIndex] + streamIndex];
}

UInt64 GetFilePackSize(int fileIndex) const
{
int folderIndex = FileIndexToFolderIndexMap[fileIndex];
if (folderIndex >= 0)
{
const CSzFolder &folderInfo = Folders[folderIndex];
if (FolderStartFileIndex[folderIndex] == fileIndex)
return GetFolderFullPackSize(folderIndex);
}
return 0;
}
*/

#define MY_ALLOC(T, p, size, alloc) { if ((size) == 0) p = 0; else \
	if ((p = (T *)IAlloc_Alloc(alloc, (size) * sizeof(T))) == 0) return SZ_ERROR_MEM; }

static SRes SzArEx_Fill(CSzArEx *p, ISzAlloc *alloc)
{
	UInt32 startPos = 0;
	UInt64 startPosSize = 0;
	UInt32 i;
	UInt32 folderIndex = 0;
	UInt32 indexInFolder = 0;
	MY_ALLOC(UInt32, p->FolderStartPackStreamIndex, p->db.NumFolders, alloc);
	for (i = 0; i < p->db.NumFolders; i++)
	{
		p->FolderStartPackStreamIndex[i] = startPos;
		startPos += p->db.Folders[i].NumPackStreams;
	}

	MY_ALLOC(UInt64, p->PackStreamStartPositions, p->db.NumPackStreams, alloc);

	for (i = 0; i < p->db.NumPackStreams; i++)
	{
		p->PackStreamStartPositions[i] = startPosSize;
		startPosSize += p->db.PackSizes[i];
	}

	MY_ALLOC(UInt32, p->FolderStartFileIndex, p->db.NumFolders, alloc);
	MY_ALLOC(UInt32, p->FileIndexToFolderIndexMap, p->db.NumFiles, alloc);

	for (i = 0; i < p->db.NumFiles; i++)
	{
		CSzFileItem *file = p->db.Files + i;
		int emptyStream = !file->HasStream;
		if (emptyStream && indexInFolder == 0)
		{
			p->FileIndexToFolderIndexMap[i] = (UInt32)-1;
			continue;
		}
		if (indexInFolder == 0)
		{
			/*
			v3.13 incorrectly worked with empty folders
			v4.07: Loop for skipping empty folders
			*/
			for (;;)
			{
				if (folderIndex >= p->db.NumFolders)
					return SZ_ERROR_ARCHIVE;
				p->FolderStartFileIndex[folderIndex] = i;
				if (p->db.Folders[folderIndex].NumUnpackStreams != 0)
					break;
				folderIndex++;
			}
		}
		p->FileIndexToFolderIndexMap[i] = folderIndex;
		if (emptyStream)
			continue;
		indexInFolder++;
		if (indexInFolder >= p->db.Folders[folderIndex].NumUnpackStreams)
		{
			folderIndex++;
			indexInFolder = 0;
		}
	}
	return SZ_OK;
}


UInt64 SzArEx_GetFolderStreamPos(const CSzArEx *p, UInt32 folderIndex, UInt32 indexInFolder)
{
	return p->dataPos +
		p->PackStreamStartPositions[p->FolderStartPackStreamIndex[folderIndex] + indexInFolder];
}

int SzArEx_GetFolderFullPackSize(const CSzArEx *p, UInt32 folderIndex, UInt64 *resSize)
{
	UInt32 packStreamIndex = p->FolderStartPackStreamIndex[folderIndex];
	CSzFolder *folder = p->db.Folders + folderIndex;
	UInt64 size = 0;
	UInt32 i;
	for (i = 0; i < folder->NumPackStreams; i++)
	{
		UInt64 t = size + p->db.PackSizes[packStreamIndex + i];
		if (t < size) /* check it */
			return SZ_ERROR_FAIL;
		size = t;
	}
	*resSize = size;
	return SZ_OK;
}


/*
SRes SzReadTime(const CObjectVector<CBuf> &dataVector,
CObjectVector<CSzFileItem> &files, UInt64 type)
{
CBoolVector boolVector;
RINOK(ReadBoolVector2(files.Size(), boolVector))

CStreamSwitch streamSwitch;
RINOK(streamSwitch.Set(this, &dataVector));

for (int i = 0; i < files.Size(); i++)
{
CSzFileItem &file = files[i];
CArchiveFileTime fileTime;
bool defined = boolVector[i];
if (defined)
{
UInt32 low, high;
RINOK(SzReadUInt32(low));
RINOK(SzReadUInt32(high));
fileTime.dwLowDateTime = low;
fileTime.dwHighDateTime = high;
}
switch(type)
{
case k7zIdCTime: file.IsCTimeDefined = defined; if (defined) file.CTime = fileTime; break;
case k7zIdATime: file.IsATimeDefined = defined; if (defined) file.ATime = fileTime; break;
case k7zIdMTime: file.IsMTimeDefined = defined; if (defined) file.MTime = fileTime; break;
}
}
return SZ_OK;
}
*/

static int TestSignatureCandidate(Byte *testBytes)
{
	size_t i;
	for (i = 0; i < k7zSignatureSize; i++)
		if (testBytes[i] != k7zSignature[i])
			return 0;
	return 1;
}

typedef struct _CSzState
{
	Byte *Data;
	size_t Size;
}CSzData;

static SRes SzReadByte(CSzData *sd, Byte *b)
{
	if (sd->Size == 0)
		return SZ_ERROR_ARCHIVE;
	sd->Size--;
	*b = *sd->Data++;
	return SZ_OK;
}

static SRes SzReadBytes(CSzData *sd, Byte *data, size_t size)
{
	size_t i;
	for (i = 0; i < size; i++)
	{
		RINOK(SzReadByte(sd, data + i));
	}
	return SZ_OK;
}

static SRes SzReadUInt32(CSzData *sd, UInt32 *value)
{
	int i;
	*value = 0;
	for (i = 0; i < 4; i++)
	{
		Byte b;
		RINOK(SzReadByte(sd, &b));
		*value |= ((UInt32)(b) << (8 * i));
	}
	return SZ_OK;
}

static SRes SzReadNumber(CSzData *sd, UInt64 *value)
{
	Byte firstByte;
	Byte mask = 0x80;
	int i;
	RINOK(SzReadByte(sd, &firstByte));
	*value = 0;
	for (i = 0; i < 8; i++)
	{
		Byte b;
		if ((firstByte & mask) == 0)
		{
			UInt64 highPart = firstByte & (mask - 1);
			*value += (highPart << (8 * i));
			return SZ_OK;
		}
		RINOK(SzReadByte(sd, &b));
		*value |= ((UInt64)b << (8 * i));
		mask >>= 1;
	}
	return SZ_OK;
}

static SRes SzReadNumber32(CSzData *sd, UInt32 *value)
{
	UInt64 value64;
	RINOK(SzReadNumber(sd, &value64));
	if (value64 >= 0x80000000)
		return SZ_ERROR_UNSUPPORTED;
	if (value64 >= ((UInt64)(1) << ((sizeof(size_t) - 1) * 8 + 2)))
		return SZ_ERROR_UNSUPPORTED;
	*value = (UInt32)value64;
	return SZ_OK;
}

static SRes SzReadID(CSzData *sd, UInt64 *value)
{
	return SzReadNumber(sd, value);
}

static SRes SzSkeepDataSize(CSzData *sd, UInt64 size)
{
	if (size > sd->Size)
		return SZ_ERROR_ARCHIVE;
	sd->Size -= (size_t)size;
	sd->Data += (size_t)size;
	return SZ_OK;
}

static SRes SzSkeepData(CSzData *sd)
{
	UInt64 size;
	RINOK(SzReadNumber(sd, &size));
	return SzSkeepDataSize(sd, size);
}

static SRes SzReadArchiveProperties(CSzData *sd)
{
	for (;;)
	{
		UInt64 type;
		RINOK(SzReadID(sd, &type));
		if (type == k7zIdEnd)
			break;
		SzSkeepData(sd);
	}
	return SZ_OK;
}

static SRes SzWaitAttribute(CSzData *sd, UInt64 attribute)
{
	for (;;)
	{
		UInt64 type;
		RINOK(SzReadID(sd, &type));
		if (type == attribute)
			return SZ_OK;
		if (type == k7zIdEnd)
			return SZ_ERROR_ARCHIVE;
		RINOK(SzSkeepData(sd));
	}
}

static SRes SzReadBoolVector(CSzData *sd, size_t numItems, Byte **v, ISzAlloc *alloc)
{
	Byte b = 0;
	Byte mask = 0;
	size_t i;
	MY_ALLOC(Byte, *v, numItems, alloc);
	for (i = 0; i < numItems; i++)
	{
		if (mask == 0)
		{
			RINOK(SzReadByte(sd, &b));
			mask = 0x80;
		}
		(*v)[i] = (Byte)(((b & mask) != 0) ? 1 : 0);
		mask >>= 1;
	}
	return SZ_OK;
}

static SRes SzReadBoolVector2(CSzData *sd, size_t numItems, Byte **v, ISzAlloc *alloc)
{
	Byte allAreDefined;
	size_t i;
	RINOK(SzReadByte(sd, &allAreDefined));
	if (allAreDefined == 0)
		return SzReadBoolVector(sd, numItems, v, alloc);
	MY_ALLOC(Byte, *v, numItems, alloc);
	for (i = 0; i < numItems; i++)
		(*v)[i] = 1;
	return SZ_OK;
}

static SRes SzReadHashDigests(
	CSzData *sd,
	size_t numItems,
	Byte **digestsDefined,
	UInt32 **digests,
	ISzAlloc *alloc)
{
	size_t i;
	RINOK(SzReadBoolVector2(sd, numItems, digestsDefined, alloc));
	MY_ALLOC(UInt32, *digests, numItems, alloc);
	for (i = 0; i < numItems; i++)
		if ((*digestsDefined)[i])
		{
			RINOK(SzReadUInt32(sd, (*digests) + i));
		}
		return SZ_OK;
}

static SRes SzReadPackInfo(
	CSzData *sd,
	UInt64 *dataOffset,
	UInt32 *numPackStreams,
	UInt64 **packSizes,
	Byte **packCRCsDefined,
	UInt32 **packCRCs,
	ISzAlloc *alloc)
{
	UInt32 i;
	RINOK(SzReadNumber(sd, dataOffset));
	RINOK(SzReadNumber32(sd, numPackStreams));

	RINOK(SzWaitAttribute(sd, k7zIdSize));

	MY_ALLOC(UInt64, *packSizes, (size_t)*numPackStreams, alloc);

	for (i = 0; i < *numPackStreams; i++)
	{
		RINOK(SzReadNumber(sd, (*packSizes) + i));
	}

	for (;;)
	{
		UInt64 type;
		RINOK(SzReadID(sd, &type));
		if (type == k7zIdEnd)
			break;
		if (type == k7zIdCRC)
		{
			RINOK(SzReadHashDigests(sd, (size_t)*numPackStreams, packCRCsDefined, packCRCs, alloc));
			continue;
		}
		RINOK(SzSkeepData(sd));
	}
	if (*packCRCsDefined == 0)
	{
		MY_ALLOC(Byte, *packCRCsDefined, (size_t)*numPackStreams, alloc);
		MY_ALLOC(UInt32, *packCRCs, (size_t)*numPackStreams, alloc);
		for (i = 0; i < *numPackStreams; i++)
		{
			(*packCRCsDefined)[i] = 0;
			(*packCRCs)[i] = 0;
		}
	}
	return SZ_OK;
}

static SRes SzReadSwitch(CSzData *sd)
{
	Byte external;
	RINOK(SzReadByte(sd, &external));
	return (external == 0) ? SZ_OK: SZ_ERROR_UNSUPPORTED;
}

static SRes SzGetNextFolderItem(CSzData *sd, CSzFolder *folder, ISzAlloc *alloc)
{
	UInt32 numCoders, numBindPairs, numPackStreams, i;
	UInt32 numInStreams = 0, numOutStreams = 0;

	RINOK(SzReadNumber32(sd, &numCoders));
	if (numCoders > NUM_FOLDER_CODERS_MAX)
		return SZ_ERROR_UNSUPPORTED;
	folder->NumCoders = numCoders;

	MY_ALLOC(CSzCoderInfo, folder->Coders, (size_t)numCoders, alloc);

	for (i = 0; i < numCoders; i++)
		SzCoderInfo_Init(folder->Coders + i);

	for (i = 0; i < numCoders; i++)
	{
		Byte mainByte;
		CSzCoderInfo *coder = folder->Coders + i;
		{
			unsigned idSize, j;
			Byte longID[15];
			RINOK(SzReadByte(sd, &mainByte));
			idSize = (unsigned)(mainByte & 0xF);
			RINOK(SzReadBytes(sd, longID, idSize));
			if (idSize > sizeof(coder->MethodID))
				return SZ_ERROR_UNSUPPORTED;
			coder->MethodID = 0;
			for (j = 0; j < idSize; j++)
				coder->MethodID |= (UInt64)longID[idSize - 1 - j] << (8 * j);

			if ((mainByte & 0x10) != 0)
			{
				RINOK(SzReadNumber32(sd, &coder->NumInStreams));
				RINOK(SzReadNumber32(sd, &coder->NumOutStreams));
				if (coder->NumInStreams > NUM_CODER_STREAMS_MAX ||
					coder->NumOutStreams > NUM_CODER_STREAMS_MAX)
					return SZ_ERROR_UNSUPPORTED;
			}
			else
			{
				coder->NumInStreams = 1;
				coder->NumOutStreams = 1;
			}
			if ((mainByte & 0x20) != 0)
			{
				UInt64 propertiesSize = 0;
				RINOK(SzReadNumber(sd, &propertiesSize));
				if (!Buf_Create(&coder->Props, (size_t)propertiesSize, alloc))
					return SZ_ERROR_MEM;
				RINOK(SzReadBytes(sd, coder->Props.data, (size_t)propertiesSize));
			}
		}
		while ((mainByte & 0x80) != 0)
		{
			RINOK(SzReadByte(sd, &mainByte));
			RINOK(SzSkeepDataSize(sd, (mainByte & 0xF)));
			if ((mainByte & 0x10) != 0)
			{
				UInt32 n;
				RINOK(SzReadNumber32(sd, &n));
				RINOK(SzReadNumber32(sd, &n));
			}
			if ((mainByte & 0x20) != 0)
			{
				UInt64 propertiesSize = 0;
				RINOK(SzReadNumber(sd, &propertiesSize));
				RINOK(SzSkeepDataSize(sd, propertiesSize));
			}
		}
		numInStreams += coder->NumInStreams;
		numOutStreams += coder->NumOutStreams;
	}

	if (numOutStreams == 0)
		return SZ_ERROR_UNSUPPORTED;

	folder->NumBindPairs = numBindPairs = numOutStreams - 1;
	MY_ALLOC(CSzBindPair, folder->BindPairs, (size_t)numBindPairs, alloc);

	for (i = 0; i < numBindPairs; i++)
	{
		CSzBindPair *bp = folder->BindPairs + i;
		RINOK(SzReadNumber32(sd, &bp->InIndex));
		RINOK(SzReadNumber32(sd, &bp->OutIndex));
	}

	if (numInStreams < numBindPairs)
		return SZ_ERROR_UNSUPPORTED;

	folder->NumPackStreams = numPackStreams = numInStreams - numBindPairs;
	MY_ALLOC(UInt32, folder->PackStreams, (size_t)numPackStreams, alloc);

	if (numPackStreams == 1)
	{
		for (i = 0; i < numInStreams ; i++)
			if (SzFolder_FindBindPairForInStream(folder, i) < 0)
				break;
		if (i == numInStreams)
			return SZ_ERROR_UNSUPPORTED;
		folder->PackStreams[0] = i;
	}
	else
		for (i = 0; i < numPackStreams; i++)
		{
			RINOK(SzReadNumber32(sd, folder->PackStreams + i));
		}
		return SZ_OK;
}

static SRes SzReadUnpackInfo(
	CSzData *sd,
	UInt32 *numFolders,
	CSzFolder **folders,  /* for alloc */
	ISzAlloc *alloc,
	ISzAlloc *allocTemp)
{
	UInt32 i;
	RINOK(SzWaitAttribute(sd, k7zIdFolder));
	RINOK(SzReadNumber32(sd, numFolders));
	{
		RINOK(SzReadSwitch(sd));

		MY_ALLOC(CSzFolder, *folders, (size_t)*numFolders, alloc);

		for (i = 0; i < *numFolders; i++)
			SzFolder_Init((*folders) + i);

		for (i = 0; i < *numFolders; i++)
		{
			RINOK(SzGetNextFolderItem(sd, (*folders) + i, alloc));
		}
	}

	RINOK(SzWaitAttribute(sd, k7zIdCodersUnpackSize));

	for (i = 0; i < *numFolders; i++)
	{
		UInt32 j;
		CSzFolder *folder = (*folders) + i;
		UInt32 numOutStreams = SzFolder_GetNumOutStreams(folder);

		MY_ALLOC(UInt64, folder->UnpackSizes, (size_t)numOutStreams, alloc);

		for (j = 0; j < numOutStreams; j++)
		{
			RINOK(SzReadNumber(sd, folder->UnpackSizes + j));
		}
	}

	for (;;)
	{
		UInt64 type;
		RINOK(SzReadID(sd, &type));
		if (type == k7zIdEnd)
			return SZ_OK;
		if (type == k7zIdCRC)
		{
			SRes res;
			Byte *crcsDefined = 0;
			UInt32 *crcs = 0;
			res = SzReadHashDigests(sd, *numFolders, &crcsDefined, &crcs, allocTemp);
			if (res == SZ_OK)
			{
				for (i = 0; i < *numFolders; i++)
				{
					CSzFolder *folder = (*folders) + i;
					folder->UnpackCRCDefined = crcsDefined[i];
					folder->UnpackCRC = crcs[i];
				}
			}
			IAlloc_Free(allocTemp, crcs);
			IAlloc_Free(allocTemp, crcsDefined);
			RINOK(res);
			continue;
		}
		RINOK(SzSkeepData(sd));
	}
}

static SRes SzReadSubStreamsInfo(
	CSzData *sd,
	UInt32 numFolders,
	CSzFolder *folders,
	UInt32 *numUnpackStreams,
	UInt64 **unpackSizes,
	Byte **digestsDefined,
	UInt32 **digests,
	ISzAlloc *allocTemp)
{
	UInt64 type = 0;
	UInt32 i;
	UInt32 si = 0;
	UInt32 numDigests = 0;

	for (i = 0; i < numFolders; i++)
		folders[i].NumUnpackStreams = 1;
	*numUnpackStreams = numFolders;

	for (;;)
	{
		RINOK(SzReadID(sd, &type));
		if (type == k7zIdNumUnpackStream)
		{
			*numUnpackStreams = 0;
			for (i = 0; i < numFolders; i++)
			{
				UInt32 numStreams;
				RINOK(SzReadNumber32(sd, &numStreams));
				folders[i].NumUnpackStreams = numStreams;
				*numUnpackStreams += numStreams;
			}
			continue;
		}
		if (type == k7zIdCRC || type == k7zIdSize)
			break;
		if (type == k7zIdEnd)
			break;
		RINOK(SzSkeepData(sd));
	}

	if (*numUnpackStreams == 0)
	{
		*unpackSizes = 0;
		*digestsDefined = 0;
		*digests = 0;
	}
	else
	{
		*unpackSizes = (UInt64 *)IAlloc_Alloc(allocTemp, (size_t)*numUnpackStreams * sizeof(UInt64));
		RINOM(*unpackSizes);
		*digestsDefined = (Byte *)IAlloc_Alloc(allocTemp, (size_t)*numUnpackStreams * sizeof(Byte));
		RINOM(*digestsDefined);
		*digests = (UInt32 *)IAlloc_Alloc(allocTemp, (size_t)*numUnpackStreams * sizeof(UInt32));
		RINOM(*digests);
	}

	for (i = 0; i < numFolders; i++)
	{
		/*
		v3.13 incorrectly worked with empty folders
		v4.07: we check that folder is empty
		*/
		UInt64 sum = 0;
		UInt32 j;
		UInt32 numSubstreams = folders[i].NumUnpackStreams;
		if (numSubstreams == 0)
			continue;
		if (type == k7zIdSize)
			for (j = 1; j < numSubstreams; j++)
			{
				UInt64 size;
				RINOK(SzReadNumber(sd, &size));
				(*unpackSizes)[si++] = size;
				sum += size;
			}
			(*unpackSizes)[si++] = SzFolder_GetUnpackSize(folders + i) - sum;
	}
	if (type == k7zIdSize)
	{
		RINOK(SzReadID(sd, &type));
	}

	for (i = 0; i < *numUnpackStreams; i++)
	{
		(*digestsDefined)[i] = 0;
		(*digests)[i] = 0;
	}


	for (i = 0; i < numFolders; i++)
	{
		UInt32 numSubstreams = folders[i].NumUnpackStreams;
		if (numSubstreams != 1 || !folders[i].UnpackCRCDefined)
			numDigests += numSubstreams;
	}


	si = 0;
	for (;;)
	{
		if (type == k7zIdCRC)
		{
			int digestIndex = 0;
			Byte *digestsDefined2 = 0;
			UInt32 *digests2 = 0;
			SRes res = SzReadHashDigests(sd, numDigests, &digestsDefined2, &digests2, allocTemp);
			if (res == SZ_OK)
			{
				for (i = 0; i < numFolders; i++)
				{
					CSzFolder *folder = folders + i;
					UInt32 numSubstreams = folder->NumUnpackStreams;
					if (numSubstreams == 1 && folder->UnpackCRCDefined)
					{
						(*digestsDefined)[si] = 1;
						(*digests)[si] = folder->UnpackCRC;
						si++;
					}
					else
					{
						UInt32 j;
						for (j = 0; j < numSubstreams; j++, digestIndex++)
						{
							(*digestsDefined)[si] = digestsDefined2[digestIndex];
							(*digests)[si] = digests2[digestIndex];
							si++;
						}
					}
				}
			}
			IAlloc_Free(allocTemp, digestsDefined2);
			IAlloc_Free(allocTemp, digests2);
			RINOK(res);
		}
		else if (type == k7zIdEnd)
			return SZ_OK;
		else
		{
			RINOK(SzSkeepData(sd));
		}
		RINOK(SzReadID(sd, &type));
	}
}


static SRes SzReadStreamsInfo(
	CSzData *sd,
	UInt64 *dataOffset,
	CSzAr *p,
	UInt32 *numUnpackStreams,
	UInt64 **unpackSizes, /* allocTemp */
	Byte **digestsDefined,   /* allocTemp */
	UInt32 **digests,        /* allocTemp */
	ISzAlloc *alloc,
	ISzAlloc *allocTemp)
{
	for (;;)
	{
		UInt64 type;
		RINOK(SzReadID(sd, &type));
		if ((UInt64)(int)type != type)
			return SZ_ERROR_UNSUPPORTED;
		switch((int)type)
		{
		case k7zIdEnd:
			return SZ_OK;
		case k7zIdPackInfo:
			{
				RINOK(SzReadPackInfo(sd, dataOffset, &p->NumPackStreams,
					&p->PackSizes, &p->PackCRCsDefined, &p->PackCRCs, alloc));
				break;
			}
		case k7zIdUnpackInfo:
			{
				RINOK(SzReadUnpackInfo(sd, &p->NumFolders, &p->Folders, alloc, allocTemp));
				break;
			}
		case k7zIdSubStreamsInfo:
			{
				RINOK(SzReadSubStreamsInfo(sd, p->NumFolders, p->Folders,
					numUnpackStreams, unpackSizes, digestsDefined, digests, allocTemp));
				break;
			}
		default:
			return SZ_ERROR_UNSUPPORTED;
		}
	}
}

size_t SzArEx_GetFileNameUtf16(const CSzArEx *p, size_t fileIndex, UInt16 *dest)
{
	size_t len = p->FileNameOffsets[fileIndex + 1] - p->FileNameOffsets[fileIndex];
	if (dest != 0)
	{
		size_t i;
		const Byte *src = p->FileNames.data + (p->FileNameOffsets[fileIndex] * 2);
		for (i = 0; i < len; i++)
			dest[i] = GetUi16(src + i * 2);
	}
	return len;
}

static SRes SzReadFileNames(const Byte *p, size_t size, UInt32 numFiles, size_t *sizes)
{
	UInt32 i;
	size_t pos = 0;
	for (i = 0; i < numFiles; i++)
	{
		sizes[i] = pos;
		for (;;)
		{
			if (pos >= size)
				return SZ_ERROR_ARCHIVE;
			if (p[pos * 2] == 0 && p[pos * 2 + 1] == 0)
				break;
			pos++;
		}
		pos++;
	}
	sizes[i] = pos;
	return (pos == size) ? SZ_OK : SZ_ERROR_ARCHIVE;
}

static SRes SzReadHeader2(
	CSzArEx *p,   /* allocMain */
	CSzData *sd,
	UInt64 **unpackSizes,  /* allocTemp */
	Byte **digestsDefined,    /* allocTemp */
	UInt32 **digests,         /* allocTemp */
	Byte **emptyStreamVector, /* allocTemp */
	Byte **emptyFileVector,   /* allocTemp */
	Byte **lwtVector,         /* allocTemp */
	ISzAlloc *allocMain,
	ISzAlloc *allocTemp)
{
	UInt64 type;
	UInt32 numUnpackStreams = 0;
	UInt32 numFiles = 0;
	CSzFileItem *files = 0;
	UInt32 numEmptyStreams = 0;
	UInt32 i;

	RINOK(SzReadID(sd, &type));

	if (type == k7zIdArchiveProperties)
	{
		RINOK(SzReadArchiveProperties(sd));
		RINOK(SzReadID(sd, &type));
	}


	if (type == k7zIdMainStreamsInfo)
	{
		RINOK(SzReadStreamsInfo(sd,
			&p->dataPos,
			&p->db,
			&numUnpackStreams,
			unpackSizes,
			digestsDefined,
			digests, allocMain, allocTemp));
		p->dataPos += p->startPosAfterHeader;
		RINOK(SzReadID(sd, &type));
	}

	if (type == k7zIdEnd)
		return SZ_OK;
	if (type != k7zIdFilesInfo)
		return SZ_ERROR_ARCHIVE;

	RINOK(SzReadNumber32(sd, &numFiles));
	p->db.NumFiles = numFiles;

	MY_ALLOC(CSzFileItem, files, (size_t)numFiles, allocMain);

	p->db.Files = files;
	for (i = 0; i < numFiles; i++)
		SzFile_Init(files + i);

	for (;;)
	{
		UInt64 type;
		UInt64 size;
		RINOK(SzReadID(sd, &type));
		if (type == k7zIdEnd)
			break;
		RINOK(SzReadNumber(sd, &size));
		if (size > sd->Size)
			return SZ_ERROR_ARCHIVE;
		if ((UInt64)(int)type != type)
		{
			RINOK(SzSkeepDataSize(sd, size));
		}
		else
			switch((int)type)
		{
			case k7zIdName:
				{
					size_t namesSize;
					RINOK(SzReadSwitch(sd));
					namesSize = (size_t)size - 1;
					if ((namesSize & 1) != 0)
						return SZ_ERROR_ARCHIVE;
					if (!Buf_Create(&p->FileNames, namesSize, allocMain))
						return SZ_ERROR_MEM;
					MY_ALLOC(size_t, p->FileNameOffsets, numFiles + 1, allocMain);
					memcpy(p->FileNames.data, sd->Data, namesSize);
					RINOK(SzReadFileNames(sd->Data, namesSize >> 1, numFiles, p->FileNameOffsets))
						RINOK(SzSkeepDataSize(sd, namesSize));
					break;
				}
			case k7zIdEmptyStream:
				{
					RINOK(SzReadBoolVector(sd, numFiles, emptyStreamVector, allocTemp));
					numEmptyStreams = 0;
					for (i = 0; i < numFiles; i++)
						if ((*emptyStreamVector)[i])
							numEmptyStreams++;
					break;
				}
			case k7zIdEmptyFile:
				{
					RINOK(SzReadBoolVector(sd, numEmptyStreams, emptyFileVector, allocTemp));
					break;
				}
			case k7zIdWinAttributes:
				{
					RINOK(SzReadBoolVector2(sd, numFiles, lwtVector, allocTemp));
					RINOK(SzReadSwitch(sd));
					for (i = 0; i < numFiles; i++)
					{
						CSzFileItem *f = &files[i];
						Byte defined = (*lwtVector)[i];
						f->AttribDefined = defined;
						f->Attrib = 0;
						if (defined)
						{
							RINOK(SzReadUInt32(sd, &f->Attrib));
						}
					}
					IAlloc_Free(allocTemp, *lwtVector);
					*lwtVector = NULL;
					break;
				}
			case k7zIdMTime:
				{
					RINOK(SzReadBoolVector2(sd, numFiles, lwtVector, allocTemp));
					RINOK(SzReadSwitch(sd));
					for (i = 0; i < numFiles; i++)
					{
						CSzFileItem *f = &files[i];
						Byte defined = (*lwtVector)[i];
						f->MTimeDefined = defined;
						f->MTime.Low = f->MTime.High = 0;
						if (defined)
						{
							RINOK(SzReadUInt32(sd, &f->MTime.Low));
							RINOK(SzReadUInt32(sd, &f->MTime.High));
						}
					}
					IAlloc_Free(allocTemp, *lwtVector);
					*lwtVector = NULL;
					break;
				}
			default:
				{
					RINOK(SzSkeepDataSize(sd, size));
				}
		}
	}

	{
		UInt32 emptyFileIndex = 0;
		UInt32 sizeIndex = 0;
		for (i = 0; i < numFiles; i++)
		{
			CSzFileItem *file = files + i;
			file->IsAnti = 0;
			if (*emptyStreamVector == 0)
				file->HasStream = 1;
			else
				file->HasStream = (Byte)((*emptyStreamVector)[i] ? 0 : 1);
			if (file->HasStream)
			{
				file->IsDir = 0;
				file->Size = (*unpackSizes)[sizeIndex];
				file->Crc = (*digests)[sizeIndex];
				file->CrcDefined = (Byte)(*digestsDefined)[sizeIndex];
				sizeIndex++;
			}
			else
			{
				if (*emptyFileVector == 0)
					file->IsDir = 1;
				else
					file->IsDir = (Byte)((*emptyFileVector)[emptyFileIndex] ? 0 : 1);
				emptyFileIndex++;
				file->Size = 0;
				file->Crc = 0;
				file->CrcDefined = 0;
			}
		}
	}
	return SzArEx_Fill(p, allocMain);
}

static SRes SzReadHeader(
	CSzArEx *p,
	CSzData *sd,
	ISzAlloc *allocMain,
	ISzAlloc *allocTemp)
{
	UInt64 *unpackSizes = 0;
	Byte *digestsDefined = 0;
	UInt32 *digests = 0;
	Byte *emptyStreamVector = 0;
	Byte *emptyFileVector = 0;
	Byte *lwtVector = 0;
	SRes res = SzReadHeader2(p, sd,
		&unpackSizes, &digestsDefined, &digests,
		&emptyStreamVector, &emptyFileVector, &lwtVector,
		allocMain, allocTemp);
	IAlloc_Free(allocTemp, unpackSizes);
	IAlloc_Free(allocTemp, digestsDefined);
	IAlloc_Free(allocTemp, digests);
	IAlloc_Free(allocTemp, emptyStreamVector);
	IAlloc_Free(allocTemp, emptyFileVector);
	IAlloc_Free(allocTemp, lwtVector);
	return res;
}

static SRes SzReadAndDecodePackedStreams2(ILookInStream *inStream, CSzData *sd, CBuf *outBuffer, UInt64 baseOffset,
	CSzAr *p, UInt64 **unpackSizes, Byte **digestsDefined, UInt32 **digests,ISzAlloc *allocTemp)
{

	UInt32 numUnpackStreams = 0;
	UInt64 dataStartPos;
	CSzFolder *folder;
	UInt64 unpackSize;
	SRes res;

	RINOK(SzReadStreamsInfo(sd, &dataStartPos, p,
		&numUnpackStreams,  unpackSizes, digestsDefined, digests,
		allocTemp, allocTemp));

	dataStartPos += baseOffset;
	if (p->NumFolders != 1)
		return SZ_ERROR_ARCHIVE;

	folder = p->Folders;
	unpackSize = SzFolder_GetUnpackSize(folder);

	RINOK(LookInStream_SeekTo(inStream, dataStartPos));

	if (!Buf_Create(outBuffer, (size_t)unpackSize, allocTemp))
		return SZ_ERROR_MEM;

	res = SzFolder_Decode(folder, p->PackSizes,
		inStream, dataStartPos,
		outBuffer->data, (size_t)unpackSize, allocTemp);
	RINOK(res);
	if (folder->UnpackCRCDefined)
		if (CrcCalc(outBuffer->data, (size_t)unpackSize) != folder->UnpackCRC)
			return SZ_ERROR_CRC;
	return SZ_OK;
}

static SRes SzReadAndDecodePackedStreams(ILookInStream *inStream, CSzData *sd, CBuf *outBuffer, UInt64 baseOffset, ISzAlloc *allocTemp)
{
	CSzAr p;
	UInt64 *unpackSizes = 0;
	Byte *digestsDefined = 0;
	UInt32 *digests = 0;
	SRes res;
	SzAr_Init(&p);
	res = SzReadAndDecodePackedStreams2(inStream, sd, outBuffer, baseOffset,
		&p, &unpackSizes, &digestsDefined, &digests,
		allocTemp);
	SzAr_Free(&p, allocTemp);
	IAlloc_Free(allocTemp, unpackSizes);
	IAlloc_Free(allocTemp, digestsDefined);
	IAlloc_Free(allocTemp, digests);
	return res;
}

static SRes SzArEx_Open2(
	CSzArEx *p,
	ILookInStream *inStream,
	ISzAlloc *allocMain,
	ISzAlloc *allocTemp)
{
	Byte header[k7zStartHeaderSize];
	Int64 startArcPos;
	UInt64 nextHeaderOffset, nextHeaderSize;
	size_t nextHeaderSizeT;
	UInt32 nextHeaderCRC;
	CBuf buffer;
	SRes res;

	startArcPos = 0;
	RINOK(inStream->Seek(inStream, &startArcPos, SZ_SEEK_CUR));

	RINOK(LookInStream_Read2(inStream, header, k7zStartHeaderSize, SZ_ERROR_NO_ARCHIVE));

	if (!TestSignatureCandidate(header))
		return SZ_ERROR_NO_ARCHIVE;
	if (header[6] != k7zMajorVersion)
		return SZ_ERROR_UNSUPPORTED;

	nextHeaderOffset = GetUi64(header + 12);
	nextHeaderSize = GetUi64(header + 20);
	nextHeaderCRC = GetUi32(header + 28);

	p->startPosAfterHeader = startArcPos + k7zStartHeaderSize;

	if (CrcCalc(header + 12, 20) != GetUi32(header + 8))
		return SZ_ERROR_CRC;

	nextHeaderSizeT = (size_t)nextHeaderSize;
	if (nextHeaderSizeT != nextHeaderSize)
		return SZ_ERROR_MEM;
	if (nextHeaderSizeT == 0)
		return SZ_OK;
	if (nextHeaderOffset > nextHeaderOffset + nextHeaderSize ||
		nextHeaderOffset > nextHeaderOffset + nextHeaderSize + k7zStartHeaderSize)
		return SZ_ERROR_NO_ARCHIVE;

	{
		Int64 pos = 0;
		RINOK(inStream->Seek(inStream, &pos, SZ_SEEK_END));
		if ((UInt64)pos < startArcPos + nextHeaderOffset ||
			(UInt64)pos < startArcPos + k7zStartHeaderSize + nextHeaderOffset ||
			(UInt64)pos < startArcPos + k7zStartHeaderSize + nextHeaderOffset + nextHeaderSize)
			return SZ_ERROR_INPUT_EOF;
	}

	RINOK(LookInStream_SeekTo(inStream, startArcPos + k7zStartHeaderSize + nextHeaderOffset));

	if (!Buf_Create(&buffer, nextHeaderSizeT, allocTemp))
		return SZ_ERROR_MEM;

	res = LookInStream_Read(inStream, buffer.data, nextHeaderSizeT);
	if (res == SZ_OK)
	{
		res = SZ_ERROR_ARCHIVE;
		if (CrcCalc(buffer.data, nextHeaderSizeT) == nextHeaderCRC)
		{
			CSzData sd;
			UInt64 type;
			sd.Data = buffer.data;
			sd.Size = buffer.size;
			res = SzReadID(&sd, &type);
			if (res == SZ_OK)
			{
				if (type == k7zIdEncodedHeader)
				{
					CBuf outBuffer;
					Buf_Init(&outBuffer);
					res = SzReadAndDecodePackedStreams(inStream, &sd, &outBuffer, p->startPosAfterHeader, allocTemp);
					if (res != SZ_OK)
						Buf_Free(&outBuffer, allocTemp);
					else
					{
						Buf_Free(&buffer, allocTemp);
						buffer.data = outBuffer.data;
						buffer.size = outBuffer.size;
						sd.Data = buffer.data;
						sd.Size = buffer.size;
						res = SzReadID(&sd, &type);
					}
				}
			}
			if (res == SZ_OK)
			{
				if (type == k7zIdHeader)
					res = SzReadHeader(p, &sd, allocMain, allocTemp);
				else
					res = SZ_ERROR_UNSUPPORTED;
			}
		}
	}
	Buf_Free(&buffer, allocTemp);
	return res;
}

SRes SzArEx_Open(CSzArEx *p, ILookInStream *inStream, ISzAlloc *allocMain, ISzAlloc *allocTemp)
{
	SRes res = SzArEx_Open2(p, inStream, allocMain, allocTemp);
	if (res != SZ_OK)
		SzArEx_Free(p, allocMain);
	return res;
}

SRes SzArEx_Extract( const CSzArEx *p, ILookInStream *inStream, UInt32 fileIndex, UInt32 *blockIndex, Byte **outBuffer,
	size_t *outBufferSize, size_t *offset, size_t *outSizeProcessed, ISzAlloc *allocMain, ISzAlloc *allocTemp)
{
	UInt32 folderIndex = p->FileIndexToFolderIndexMap[fileIndex];
	SRes res = SZ_OK;
	*offset = 0;
	*outSizeProcessed = 0;
	if (folderIndex == (UInt32)-1)
	{
		IAlloc_Free(allocMain, *outBuffer);
		*blockIndex = folderIndex;
		*outBuffer = 0;
		*outBufferSize = 0;
		return SZ_OK;
	}

	if (*outBuffer == 0 || *blockIndex != folderIndex)
	{
		CSzFolder *folder = p->db.Folders + folderIndex;
		UInt64 unpackSizeSpec = SzFolder_GetUnpackSize(folder);
		size_t unpackSize = (size_t)unpackSizeSpec;
		UInt64 startOffset = SzArEx_GetFolderStreamPos(p, folderIndex, 0);

		if (unpackSize != unpackSizeSpec)
			return SZ_ERROR_MEM;
		*blockIndex = folderIndex;
		IAlloc_Free(allocMain, *outBuffer);
		*outBuffer = 0;

		RINOK(LookInStream_SeekTo(inStream, startOffset));

		if (res == SZ_OK)
		{
			*outBufferSize = unpackSize;
			if (unpackSize != 0)
			{
				*outBuffer = (Byte *)IAlloc_Alloc(allocMain, unpackSize);
				if (*outBuffer == 0)
					res = SZ_ERROR_MEM;
			}
			if (res == SZ_OK)
			{
				res = SzFolder_Decode(folder, p->db.PackSizes + p->FolderStartPackStreamIndex[folderIndex],
					inStream, startOffset, *outBuffer, unpackSize, allocTemp);
			}
		}
	}
	if (res == SZ_OK)
	{
		UInt32 i;
		CSzFileItem *fileItem = p->db.Files + fileIndex;
		*offset = 0;
		for (i = p->FolderStartFileIndex[folderIndex]; i < fileIndex; i++)
			*offset += (UInt32)p->db.Files[i].Size;
		*outSizeProcessed = (size_t)fileItem->Size;
		if (*offset + *outSizeProcessed > *outBufferSize)
			return SZ_ERROR_FAIL;
	}
	return res;
}
