void ReadFrom(Stream zipStream)
{
while (zipStream.Position < zipStream.Length)
{
var reader = new BinaryReader(zipStream, Encoding.ASCII);
uint localFileHeaderSignature = reader.ReadUInt32();
if (localFileHeaderSignature != LOCAL_FILE_HEADER_SIGNATURE)
{
// Local file entries are finished, next records are central directory records
break;
}
ushort versionNeededToExtract = reader.ReadUInt16();
ushort generalPurposeBitFlag = reader.ReadUInt16();
ushort compressionMethod = reader.ReadUInt16();
if (compressionMethod != COMPRESSION_DEFLATE && compressionMethod != COMPRESSION_STORE)
{
throw new NotSupportedException(ARCHIVE_FORMAT_NOT_SUPPORTED_STRING);
}
uint lastModifiedDateTime = reader.ReadUInt32();
uint crc32 = reader.ReadUInt32();
uint compressedSize = reader.ReadUInt32();
uint uncompressedSize = reader.ReadUInt32();
ushort fileNameLength = reader.ReadUInt16();
ushort extraFieldLength = reader.ReadUInt16();
//if (extraFieldLength != 0)
//{
// throw new NotSupportedException(ARCHIVE_FORMAT_NOT_SUPPORTED_STRING);
//}
var fileNameBytes = reader.ReadBytes(fileNameLength);
Encoding fileNameEncoding = (generalPurposeBitFlag & UTF8_FILE_NAME_ENCODING_FLAG) != 0
? new UTF8Encoding()
: Encoding.GetEncoding(CultureInfo.CurrentCulture.TextInfo.OEMCodePage);
var fileName = new string(fileNameEncoding.GetChars(fileNameBytes));
// According to ZIP specification, ZIP archives generally
// contain forward slashes so make Windows file name
fileName = fileName.Replace('/', Path.DirectorySeparatorChar);
ZipEntry entry;
if (uncompressedSize != 0)
{
var fileData = reader.ReadBytes((int)compressedSize);
var fileDataStream = new MemoryStream(fileData);
var fileEntry = new ZipFileEntry(fileName, fileDataStream);
if (compressionMethod == COMPRESSION_DEFLATE)
{
fileDataStream.Position = 0;
var deflateStream = new DeflateStream(fileDataStream, CompressionMode.Decompress);
var uncompressedFileData = new byte[uncompressedSize];
deflateStream.Read(uncompressedFileData, 0, (int)uncompressedSize);
fileEntry.Data = new MemoryStream(uncompressedFileData);
}
entry = fileEntry;
}
else if (fileName.EndsWith(@"\"))
{
entry = new ZipDirectoryEntry(fileName);
}
else
{
entry = new ZipFileEntry(fileName, null);
}
_entries.Add(entry);
reader.ReadBytes(extraFieldLength);
}
}