public BasicStoredFile(BasicArchive archive, string name, long offset, long length)
{
Archive = archive;
Name = name;
Offset = offset;
Length = length;
}
public BasicDeflatedFile(BasicArchive archive, string name, long offset, long length, long compressedLength)
{
Archive = archive;
Name = name;
Offset = offset;
Length = length;
CompressedLength = compressedLength;
}
public IArchive GetArchive(IFile file, Stream stream)
{
if (stream.Length < 22)
{
return(null);
}
stream.Seek(-22, SeekOrigin.End);
if (!Utils.CheckMagic(stream, ZIPENDLOCATOR_MAGIC))
{
throw new Exception("Invalid Archive");
}
var reader = new BinaryReader(stream, Encoding.ASCII, true);
var diskNumber = reader.ReadUInt16();
var startDiskNumber = reader.ReadUInt16();
if (diskNumber != startDiskNumber)
{
throw new Exception("Incomplete Archive");
}
var fileCount = reader.ReadUInt16();
var filesInDirectory = reader.ReadUInt16();
var directorySize = reader.ReadUInt32();
var directoryOffset = reader.ReadUInt32();
var fileCommentLength = reader.ReadUInt16();
var currentOffset = directoryOffset;
var result = new BasicArchive(file, true);
while (true)
{
stream.Position = currentOffset;
if (reader.ReadUInt32() != 0x02014B50) // ZIPDIRENTRY
{
break;
}
var versionMadeBy = reader.ReadUInt16();
var versionToExtract = reader.ReadUInt16();
var flags = reader.ReadUInt16();
var compressionMethod = reader.ReadUInt16();
var fileTime = reader.ReadUInt16();
var fileDate = reader.ReadUInt16();
var crc = reader.ReadUInt32();
var compressedSize = reader.ReadUInt32();
var uncompressedSize = reader.ReadUInt32();
var nameLength = reader.ReadUInt16();
var extraLength = reader.ReadUInt16();
var commentLength = reader.ReadUInt16();
var diskNumberStart = reader.ReadUInt16();
var internalAttributes = reader.ReadUInt16();
var externalAttributes = reader.ReadUInt32();
var recordOffset = reader.ReadUInt32(); // ZIPFILERECORD
var fullName = Utils.ReadASCII(reader, nameLength);
currentOffset = (uint)stream.Position + extraLength + commentLength;
var dataOffset = recordOffset + 30 + nameLength;
if (fullName.EndsWith("/"))
{
continue;
}
if (compressionMethod == 0)
{
result.AddStoredFile(fullName, dataOffset, uncompressedSize);
}
else if (compressionMethod == 8)
{
result.AddDeflatedFile(fullName, dataOffset, uncompressedSize, compressedSize);
}
else
{
throw new Exception($"Invalid compression method: {compressionMethod} - expected STORE (0) or DEFLATE (8)");
}
}
return(result);
}