public static string GetFileNameFromZipStream(this Stream stream, LocalHeader header)
{
Span <byte> buffer = stackalloc byte[header.FileNameLenght];
stream.Read(buffer);
return(Encoding.UTF8.GetString(buffer));
}
public static void SkipExtraField(this Stream stream, LocalHeader header)
{
if (header.ExtraLenght != 0)
{
Span <byte> buffer = stackalloc byte[header.ExtraLenght];
stream.Read(buffer);
}
}
public static bool IsZip(this FileInfo info)
{
using FileStream contentStream = info.OpenRead();
return(LocalHeader.FromStream(contentStream).IsValid);
}
private static void StoreFiles(Stream zipStream, IReadOnlyList <KeyValuePair <string, string> > files)
{
var isZip64 = false;
var count = files.Count;
var isZip64Count = !GetLegacyUInt16(count, out var legacyCount);
isZip64 = isZip64 || isZip64Count;
var relativeNames = new byte[count][];
var offsets = new long[count];
var methods = new CompressionMethod[count];
var times = new ushort[count];
var dates = new ushort[count];
var crc32s = new int[count];
var compressedLengths = new long[count];
var uncompressedLengths = new long[count];
//local entries and actual data
Console.Write("Writing files.");
for (int i = 0; i < count; i++)
{
Console.Write($"\rWriting files: {i + 1}/{count}");
offsets[i] = zipStream.Position;
var location = files[i].Value;
var relativeName = files[i].Key;
var relativeNameBytes = relativeNames[i] = MiscHelpers.Encoding.GetBytes(relativeName);
using (var file = File.OpenRead(location)) {
var dateTime = File.GetLastWriteTime(file.Name);
var uncompressedLength = uncompressedLengths[i] = file.Length;
var compressedLength = compressedLengths[i] = file.Length;
var isZip64CompressedLength = !GetLegacyUInt32(compressedLength, out var legacyCompressedLength);
var isZip64UncompressedLength = !GetLegacyUInt32(uncompressedLength, out var legacyUncompressedLength);
isZip64 = isZip64 || isZip64CompressedLength || isZip64UncompressedLength;
var header = new LocalHeader {
Signature = LocalHeader.DefaultSignature,
VersionNeeded = ZipVersion,
Flags = 0,
Compression = methods[i] = CompressionMethod.Store,
Time = times[i] = MiscHelpers.GetDosTime(dateTime),
Date = dates[i] = MiscHelpers.GetDosDate(dateTime),
Crc32 = crc32s[i] = file.ComputeCrc32(uncompressedLength),
CompressedSize = legacyCompressedLength,
UncompressedSize = legacyUncompressedLength,
NameLength = MiscHelpers.EnsureFitsUInt16(relativeNameBytes.Length),
ExtraLength = 0,
};
if (isZip64CompressedLength || isZip64UncompressedLength)
{
header.ExtraLength = 4;
if (isZip64CompressedLength)
{
header.ExtraLength += 8;
}
if (isZip64UncompressedLength)
{
header.ExtraLength += 8;
}
}
zipStream.WriteValue(header);
zipStream.Write(relativeNameBytes, 0, relativeNameBytes.Length);
//zip64 extra
if (isZip64CompressedLength || isZip64UncompressedLength)
{
WriteExtraZip64Header(zipStream, header.ExtraLength);
if (isZip64UncompressedLength)
{
zipStream.WriteValue(uncompressedLengths[i]);
}
if (isZip64CompressedLength)
{
zipStream.WriteValue(compressedLengths[i]);
}
}
file.Position = 0;
file.CopyTo(zipStream);
}
}
Console.WriteLine();
var directoryStart = zipStream.Position;
var isZip64DirectoryStart = !GetLegacyUInt32(directoryStart, out var legacyDirectoryStart);
isZip64 = isZip64 || isZip64DirectoryStart;
//central directory entries
Console.Write("Writing central directory.");
for (int i = 0; i < count; i++)
{
Console.Write($"\rWriting central directory: {i + 1}/{count}");
var isZip64CompressedLength = !GetLegacyUInt32(compressedLengths[i], out var legacyCompressedLength);
var isZip64UncompressedLength = !GetLegacyUInt32(uncompressedLengths[i], out var legacyUncompressedLength);
var isZip64LocalOffset = !GetLegacyUInt32(offsets[i], out var legacyOffset);
isZip64 = isZip64 || isZip64CompressedLength || isZip64UncompressedLength || isZip64LocalOffset;
var relativeName = relativeNames[i];
var header = new DirectoryHeader {
Signature = DirectoryHeader.DefaultSignature,
VersionMadeBy = ZipVersion,
VersionNeeded = ZipVersion,
Flags = 0,
Compression = methods[i],
Time = times[i],
Date = dates[i],
Crc32 = crc32s[i],
CompressedSize = legacyCompressedLength,
UncompressedSize = legacyUncompressedLength,
NameLength = (ushort)relativeName.Length, //gets checked when writing local headers
ExtraLength = 0,
CommentLength = 0,
DiskNumber = 0,
InternalAttributes = 0,
ExternalAttributes = 0,
LocalHeaderOffset = legacyOffset,
};
if (isZip64CompressedLength || isZip64UncompressedLength || isZip64LocalOffset)
{
header.ExtraLength = 4;
if (isZip64CompressedLength)
{
header.ExtraLength += 8;
}
if (isZip64UncompressedLength)
{
header.ExtraLength += 8;
}
if (isZip64LocalOffset)
{
header.ExtraLength += 8;
}
}
zipStream.WriteValue(header);
zipStream.Write(relativeName, 0, relativeName.Length);
//zip64 extra
if (header.ExtraLength > 0)
{
WriteExtraZip64Header(zipStream, header.ExtraLength);
if (isZip64UncompressedLength)
{
zipStream.WriteValue(uncompressedLengths[i]);
}
if (isZip64CompressedLength)
{
zipStream.WriteValue(compressedLengths[i]);
}
if (isZip64LocalOffset)
{
zipStream.WriteValue(offsets[i]);
}
}
}
Console.WriteLine();
var directoryEnd = zipStream.Position;
var directorySize = directoryEnd - directoryStart;
var isZip64DirectorySize = !GetLegacyUInt32(directorySize, out var legacyDirectorySize);
isZip64 = isZip64 || isZip64DirectorySize;
if (isZip64)
{
var eod64 = new EndOfDirectory64 {
Signature = EndOfDirectory64.DefaultSignature,
Size = (ulong)(MiscHelpers.SizeOf <EndOfDirectory64> () - 4 - 8),
VersionMadeBy = ZipVersion,
VersionNeeded = ZipVersion,
DiskNumber = 0,
DirectoryDiskNumber = 0,
DiskRecords = (ulong)count,
TotalRecords = (ulong)count,
DirectorySize = (ulong)directorySize,
DirectoryOffset = (ulong)directoryStart,
};
zipStream.WriteValue(eod64);
var locator64 = new EndOfDirectory64Locator {
Signature = EndOfDirectory64Locator.DefaultSignature,
EndOfDirectory64DiskNumber = 0,
EndOfDirectory64Offset = (ulong)directoryEnd,
TotalDisks = 1,
};
zipStream.WriteValue(locator64);
}
//central directory end
var eod = new EndOfDirectory {
Signature = EndOfDirectory.DefaultSignature,
DiskNumber = 0,
DirectoryDiskNumber = 0,
DiskRecords = legacyCount,
TotalRecords = legacyCount,
DirectorySize = legacyDirectorySize,
DirectoryOffset = legacyDirectoryStart,
CommentLength = 0,
};
zipStream.WriteValue(eod);
}
