/// <summary>
/// Adds the entry.
/// </summary>
/// <param name="entryName">Name of the entry.</param>
/// <param name="stream">The stream.</param>
public void AddEntry([NotNull] string entryName, [NotNull] Stream stream)
{
if (!stream.CanRead)
{
throw new ArgumentException("Stream should be readable");
}
// To do: assert whether entry name is unique and valid
var entryInfo = new ZipEntryInfo();
entryInfo.EntryName = entryName;
entryInfo.LastModifiedDate = DateTime.Now - new TimeSpan(1, 0, 0);
Archive(stream, _outputStream, _tempFileStream, entryInfo, _encoding);
_entriesCount++;
}
private static void Archive(Stream input, Stream output, Stream headerOutput, ZipEntryInfo additionalInfo, Encoding encoding)
{
var bytes = new byte[4096];
long i = 0;
// signature
Write4Bytes(bytes, ref i, ZipConstants.ZipEntrySignature);
// version needed
short FixedVersionNeeded = 0x14; // from examining existing zip files
Write2Bytes(bytes, ref i, FixedVersionNeeded);
// bitfield
short BitField = 0x00; // from examining existing zip files
Write2Bytes(bytes, ref i, BitField);
// compression method
var offsetOfCompression = output.Position + i;
short CompressionMethod = 0x08; // 0x08 = Deflate, 0x00 == No Compression
Write2Bytes(bytes, ref i, CompressionMethod);
// LastMod
var _LastModDateTime = additionalInfo.LastModifiedDateInt;
Write4Bytes(bytes, ref i, _LastModDateTime);
// Writing zeros for Crc32, CompressedSize and UncompressedSize. Total length is 12 bytes
// This fields will be filled later, after compression
var offsetOfCrcAndSizesInHeader = i;
var offsetOfCrcAndSizes = output.Position + i;
i += 12; // Increasing offset by 12.
// filename length (Int16)
var data = encoding.GetBytes(additionalInfo.EntryName);
var length = (short)data.Length;
Write2Bytes(bytes, ref i, length);
// extra field length (short)
short ExtraFieldLength = 0x00;
Write2Bytes(bytes, ref i, ExtraFieldLength);
// actual filename
Array.Copy(data, 0, bytes, i, data.Length);
i += data.Length;
// remember the file offset of this header
long relativeOffsetOfHeader = (int)output.Position;
// finally, write the header to the stream
output.Write(bytes, 0, (int)i);
var crc32 = new CRC32();
uint crc;
var fileDataOffset = output.Position;
using (var compressedStream = new DeflateStream(output, CompressionMode.Compress, true))
{
crc = crc32.GetCrc32AndCopy(input, compressedStream);
}
var compressedSize = output.Position - fileDataOffset;
long originalSize = crc32.TotalBytesRead;
//if(originalSize == 0)
//{
// SetNoCompression(output, offsetOfCompression);
// compressedSize = 0;
// crc = 0;
// output.Seek(fileDataOffset, SeekOrigin.Begin);
//}
// We don't need the input stream, so we close it
input.Close();
WriteCrcAndSizes(output, offsetOfCrcAndSizes, crc, originalSize, compressedSize);
// Copying crc, originalSize, compressedSize to the bytes. In order to be used in central directory structure
var k = offsetOfCrcAndSizesInHeader;
Write4Bytes(bytes, ref k, (int)crc);
Write4Bytes(bytes, ref k, (int)compressedSize);
Write4Bytes(bytes, ref k, (int)originalSize);
var header = new byte[i];
Array.Copy(bytes, header, i);
WriteCenralDirectoryFileHeader(headerOutput, header, relativeOffsetOfHeader);
}
