private void WaitAttribute(DataReader mReader, BlockType type)
{
for(; ; )
{
var next = ReadBlockType(mReader);
if(next == type)
return;
if(next == BlockType.End)
throw new InvalidDataException();
SkipAttribute(mReader);
}
}
internal ReaderConstraint(DataReader reader)
{
mReader = reader;
}
private void ReadUnpackInfo(DataReader mReader, out FolderInfo[] folders)
{
WaitAttribute(mReader, BlockType.Folder);
{
int numFolders = mReader.ReadPackedUInt31();
folders = new FolderInfo[numFolders];
for(int i = 0; i < folders.Length; i++)
folders[i] = GetNextFolderItem(mReader);
}
WaitAttribute(mReader, BlockType.CodersUnpackSize);
{
for(int i = 0; i < folders.Length; i++)
{
var folder = folders[i];
folder.UnpackSizes = new ulong[folder.GetNumOutStreams()];
for(int j = 0; j < folder.UnpackSizes.Length; j++)
folder.UnpackSizes[j] = mReader.ReadPackedUInt64();
}
}
for(; ; )
{
var type = ReadBlockType(mReader);
if(type == BlockType.End)
break;
if(type == BlockType.CRC)
{
BitVector defined;
uint[] crcs;
ReadHashDigests(mReader, folders.Length, out defined, out crcs);
for(int i = 0; i < folders.Length; i++)
if(defined[i])
folders[i].UnpackCRC = crcs[i];
continue;
}
SkipAttribute(mReader);
}
}
private void SkipAttribute(DataReader mReader)
{
ulong size = mReader.ReadPackedUInt64();
if(size > (ulong)mReader.Remaining)
throw new InvalidDataException();
mReader.Skip((long)size);
}
private void ReadSubStreamsInfo(DataReader mReader, FolderInfo[] folders, out int[] numUnpackStreamsInFolders, out List<ulong> unpackSizes, out BitVector crcDefined, out uint[] crcs)
{
numUnpackStreamsInFolders = new int[folders.Length];
for(int i = 0; i < numUnpackStreamsInFolders.Length; i++)
numUnpackStreamsInFolders[i] = 1;
BlockType? type;
for(; ; )
{
type = ReadBlockType(mReader);
if(type == BlockType.NumUnpackStream)
{
for(int i = 0; i < numUnpackStreamsInFolders.Length; i++)
numUnpackStreamsInFolders[i] = mReader.ReadPackedUInt31();
continue;
}
if(type == BlockType.End || type == BlockType.CRC || type == BlockType.Size)
break;
SkipAttribute(mReader);
}
for(int i = 0; i < numUnpackStreamsInFolders.Length; i++)
{
int numSubstreams = numUnpackStreamsInFolders[i];
if(numSubstreams == 0)
continue;
ulong sum = 0;
if(type == BlockType.Size)
{
for(int j = 1; j < numSubstreams; j++)
{
ulong size = mReader.ReadPackedUInt64();
unpackSizes.Add(size);
sum += size;
}
}
unpackSizes.Add(folders[i].GetUnpackSize() - sum);
}
if(type == BlockType.Size)
type = ReadBlockType(mReader);
int numCRCs = 0;
int numCRCsTotal = 0;
for(int i = 0; i < folders.Length; i++)
{
int numSubstreams = numUnpackStreamsInFolders[i];
if(numSubstreams != 1 || folders[i].UnpackCRC == null)
numCRCs += numSubstreams;
numCRCsTotal += numSubstreams;
}
for(; ; )
{
if(type == BlockType.CRC)
{
BitVector defined2;
uint[] crcs2;
ReadHashDigests(mReader, numCRCs, out defined2, out crcs2);
}
else if(type == BlockType.End)
break;
else
SkipAttribute(mReader);
type = ReadBlockType(mReader);
}
if(crcDefined == null)
{
throw new NotImplementedException();
}
}
private FolderInfo GetNextFolderItem(DataReader mReader)
{
FolderInfo folder = new FolderInfo();
int numInStreams = 0;
int numOutStreams = 0;
int numCoders = mReader.ReadPackedUInt31();
folder.Coders = new CoderInfo[numCoders];
for(int i = 0; i < numCoders; i++)
{
CoderInfo coder = new CoderInfo();
folder.Coders[i] = coder;
byte mainByte = mReader.ReadByte();
int idSize = mainByte & 15;
if(idSize > 8) // standard 7z also is limited to 8 byte coder ids
throw new InvalidDataException();
ulong id = 0;
for(int j = idSize - 1; j >= 0; j--)
id += (ulong)mReader.ReadByte() << (j * 8);
coder.MethodId = id;
if((mainByte & 0x10) != 0)
{
coder.NumInStreams = mReader.ReadPackedUInt31();
coder.NumOutStreams = mReader.ReadPackedUInt31();
}
else
{
coder.NumInStreams = 1;
coder.NumOutStreams = 1;
}
if((mainByte & 0x20) != 0)
{
int propsSize = mReader.ReadPackedUInt31();
coder.Props = mReader.ReadBytes(propsSize);
}
// TODO: Warn if 0x40 is set, since it is not defined in the supported versions of the format.
if((mainByte & 0x80) != 0)
throw new InvalidDataException();
numInStreams += coder.NumInStreams;
numOutStreams += coder.NumOutStreams;
}
int numBindPairs = mReader.ReadPackedUInt31();
folder.BindPairs = new BindPair[numBindPairs];
for(int i = 0; i < numBindPairs; i++)
{
int inIndex = mReader.ReadPackedUInt31();
int outIndex = mReader.ReadPackedUInt31();
folder.BindPairs[i] = new BindPair(inIndex, outIndex);
}
if(numInStreams < numBindPairs)
throw new InvalidDataException();
int numPackStreams = numInStreams - numBindPairs;
folder.PackStreams = new int[numPackStreams];
if(numPackStreams == 1)
{
bool found = false;
for(int i = 0; i < numInStreams; i++)
{
if(folder.FindBindPairForInStream(i) < 0)
{
folder.PackStreams[0] = i;
found = true;
break;
}
}
if(!found)
throw new InvalidDataException();
}
else
{
for(int i = 0; i < numPackStreams; i++)
folder.PackStreams[i] = mReader.ReadPackedUInt31();
}
return folder;
}
private void ReadPackInfo(DataReader mReader, out ulong[] packSizes, out BitVector packCRCsDefined, out uint[] packCRCs)
{
packCRCsDefined = null;
packCRCs = null;
ulong dataOffset = mReader.ReadPackedUInt64();
int numPackStreams = mReader.ReadPackedUInt31();
WaitAttribute(mReader, BlockType.Size);
{
packSizes = new ulong[numPackStreams];
for(int i = 0; i < numPackStreams; i++)
packSizes[i] = mReader.ReadPackedUInt64();
}
for(; ; )
{
var type = ReadBlockType(mReader);
if(type == BlockType.End)
break;
if(type == BlockType.CRC)
ReadHashDigests(mReader, numPackStreams, out packCRCsDefined, out packCRCs);
else
SkipAttribute(mReader);
}
if(packCRCsDefined == null)
{
packCRCsDefined = new BitVector(numPackStreams);
packCRCs = new uint[numPackStreams];
}
}
private void ReadStreamsInfo(DataReader mReader, out ulong[] packSizes, out BitVector packCRCsDefined, out uint[] packCRCs, out FolderInfo[] folders,
out int[] numUnpackStreamsInFolders, out List<ulong> unpackSizes, out BitVector crcDefined, out uint[] crcs)
{
packSizes = null;
packCRCsDefined = null;
packCRCs = null;
folders = null;
numUnpackStreamsInFolders = null;
unpackSizes = null;
crcDefined = null;
crcs = null;
for(; ; )
{
var type = ReadBlockType(mReader);
switch(type)
{
case BlockType.End:
return;
case BlockType.PackInfo:
ReadPackInfo(mReader, out packSizes, out packCRCsDefined, out packCRCs);
break;
case BlockType.UnpackInfo:
ReadUnpackInfo(mReader, out folders);
break;
case BlockType.SubStreamsInfo:
ReadSubStreamsInfo(mReader, folders, out numUnpackStreamsInFolders, out unpackSizes, out crcDefined, out crcs);
break;
default:
throw new InvalidDataException();
}
}
}
private void ReadHeader(DataReader mReader)
{
byte[] signature = mReader.ReadBytes(kSignature.Length);
if(signature.Length != kSignature.Length)
throw new InvalidDataException();
for(int i = 0; i < signature.Length; i++)
if(signature[i] != kSignature[i])
throw new InvalidDataException();
mMajorVersion = mReader.ReadByte();
mMinorVersion = mReader.ReadByte();
if(mMajorVersion != 0)
throw new NotSupportedException();
// TODO: Weak check of supported minor versions
uint startHeaderCRC = mReader.ReadUInt32();
long nextHeaderOffset = mReader.ReadInt64();
long nextHeaderLength = mReader.ReadInt64();
uint nextHeaderCRC = mReader.ReadUInt32();
Utils.Assert(mReader.Position == kPrimaryHeaderSize);
if(mCheckCRC)
{
uint crc = CRC.kInitCRC;
crc = CRC.Update(crc, nextHeaderOffset);
crc = CRC.Update(crc, nextHeaderLength);
crc = CRC.Update(crc, nextHeaderCRC);
crc = CRC.Finish(crc);
if(crc != startHeaderCRC)
throw new InvalidDataException();
}
if(nextHeaderLength < 0 || nextHeaderOffset < 0
|| nextHeaderOffset > mReader.Remaining - nextHeaderLength)
throw new InvalidDataException();
if(nextHeaderLength > 0) // zero is ok, empty archive
{
mReader.Skip(nextHeaderOffset);
if(mCheckCRC)
{
if(mReader.CalculateCRC(nextHeaderLength) != nextHeaderCRC)
throw new InvalidDataException();
mReader.Seek(kPrimaryHeaderSize + nextHeaderOffset);
}
using(mReader.Constrain(nextHeaderLength))
ReadHeader2(mReader);
}
}
private void ReadHeader2(DataReader mReader)
{
var type = ReadBlockType(mReader);
if(type == BlockType.EncodedHeader)
{
// TODO: we want to do sanity checking of any offsets read from the header against the original stream, not the decoded header
Stream[] streams;
ReadAndDecodePackedStreams(mReader, out streams);
// packing an empty header is odd but ok
if(streams.Length == 0)
return; // TODO: record a warning or info message
// header must be stored in a single stream
if(streams.Length != 1)
throw new InvalidDataException();
// switch reader to use decoded header
mReader = new DataReader(streams[0]);
type = ReadBlockType(mReader);
}
if(type != BlockType.Header)
throw new InvalidDataException();
type = ReadBlockType(mReader);
if(type == BlockType.ArchiveProperties)
{
ReadArchiveProperties(mReader);
type = ReadBlockType(mReader);
}
if(type == BlockType.AdditionalStreamsInfo)
{
ReadAdditionalStreamsInfo(mReader);
type = ReadBlockType(mReader);
}
if(type == BlockType.MainStreamsInfo)
{
ReadStreamsInfo(mReader);
type = ReadBlockType(mReader);
}
if(type == BlockType.FilesInfo)
{
int numFiles = mReader.ReadPackedUInt31();
for(; ; )
{
type = ReadBlockType(mReader);
if(type == BlockType.End)
break;
ulong size = mReader.ReadPackedUInt64();
if(size > (ulong)mReader.Remaining)
throw new InvalidDataException();
switch(type)
{
case BlockType.Name:
break;
case BlockType.WinAttributes:
break;
case BlockType.EmptyStream:
break;
case BlockType.EmptyFile:
break;
case BlockType.Anti:
break;
case BlockType.StartPos:
break;
case BlockType.CTime:
break;
case BlockType.ATime:
break;
case BlockType.MTime:
break;
case BlockType.Dummy:
break;
default:
mReader.Skip(checked((long)size));
break;
}
}
}
if(type != BlockType.End)
throw new InvalidDataException();
// TODO: weak check that we actually are at the end of the header - no exception, just a warning
if(mReader.Remaining != 0)
System.Diagnostics.Debugger.Break();
}
private void ReadHashDigests(DataReader mReader, int count, out BitVector defined, out uint[] digests)
{
defined = mReader.ReadBitVector2(count);
digests = new uint[count];
for(int i = 0; i < digests.Length; i++)
if(defined[i])
digests[i] = mReader.ReadUInt32();
}
private BlockType? ReadBlockType(DataReader mReader)
{
ulong value = mReader.ReadPackedUInt64();
if(value > 25)
return null;
else
return (BlockType)value;
}
private void ReadArchiveProperties(DataReader mReader)
{
while(ReadBlockType(mReader) != BlockType.End)
SkipAttribute(mReader);
}
private void ReadAndDecodePackedStreams(DataReader mReader, out Stream[] streams)
{
FolderInfo[] folders;
ReadStreamsInfo(mReader);
int packIndex = 0;
for(int i = 0; i < folders.Length; i++)
{
var folder = folders[i];
}
}
private void ReadAdditionalStreamsInfo(DataReader mReader)
{
throw new NotSupportedException();
}
