private async Task <Tuple <byte[], DateTime> > Download(PartialZipInfo info, string filePath)
{
CentralDirectoryHeader cd = info.CentralDirectory.FirstOrDefault(c => c.FileName == filePath);
DataProp dataProp;
if (cd != null)
{
dataProp = cd.GetFileInfoStruct();
byte[] localFileBuffer = await _httpService.GetRange(dataProp.headerOffset, dataProp.headerOffset + LocalFileHeader.Size - 1);
LocalFileHeader localFileHeader = new LocalFileHeader(localFileBuffer);
ulong start = dataProp.headerOffset + LocalFileHeader.Size + localFileHeader.FileNameLength + localFileHeader.ExtraFieldLength;
byte[] compressedContent = await _httpService.GetRange(start, start + dataProp.compressedSize - 1);
var dateTimeModified = ConvertDOSDateTime(dataProp.modifiedDate, dataProp.modifiedTime);
switch (localFileHeader.Compression)
{
case 0:
return(Tuple.Create(compressedContent, dateTimeModified));
case 8:
return(Tuple.Create(_deflateService.Inflate(compressedContent), dateTimeModified));
default:
throw new PartialZipUnsupportedCompressionException("Unknown compression.");
}
}
throw new PartialZipFileNotFoundException($"Could not find file in archive.");
}
private async Task <byte[]> Download(PartialZipInfo info, string filePath)
{
CentralDirectoryHeader cd = info.CentralDirectory.FirstOrDefault(c => c.FileName == filePath);
if (cd != null)
{
(ulong uncompressedSize, ulong compressedSize, ulong headerOffset, uint diskNum) = cd.GetFileInfo();
byte[] localFileBuffer = await this._httpService.GetRange(headerOffset, headerOffset + LocalFileHeader.Size - 1);
LocalFileHeader localFileHeader = new LocalFileHeader(localFileBuffer);
ulong start = headerOffset + LocalFileHeader.Size + localFileHeader.FileNameLength + localFileHeader.ExtraFieldLength;
byte[] compressedContent = await this._httpService.GetRange(start, start + compressedSize - 1);
switch (localFileHeader.Compression)
{
case 0:
return(compressedContent);
case 8:
return(this._deflateService.Inflate(compressedContent));
default:
throw new PartialZipUnsupportedCompressionException("Unknown compression.");
}
}
throw new PartialZipFileNotFoundException($"Could not find file {filePath} in archive.");
}
internal override void PrepareForZip(CentralDirectoryHeader header = null)
{
base.PrepareForZip(header);
this.UseZipHeader = true;
if (header == null)
{
return;
}
this.InternalStreamLength = (long)header.UncompressedSize;
}
private async Task <PartialZipInfo> Open()
{
bool supportsPartialZip = await _httpService.SupportsPartialZip();
if (!supportsPartialZip)
{
throw new PartialZipNotSupportedException("The web server does not support PartialZip as byte ranges are not accepted.");
}
PartialZipInfo info = new PartialZipInfo();
info.Length = await _httpService.GetContentLength();
byte[] eocdBuffer = await _httpService.GetRange(info.Length - EndOfCentralDirectory.Size, info.Length - 1);
info.EndOfCentralDirectory = new EndOfCentralDirectory(eocdBuffer);
ulong startCD, endCD;
if (info.EndOfCentralDirectory.IsZip64)
{
byte[] eocdLocator64Buffer = await _httpService.GetRange(info.Length - EndOfCentralDirectory.Size - EndOfCentralDirectoryLocator64.Size, info.Length - EndOfCentralDirectory.Size);
info.EndOfCentralDirectoryLocator64 = new EndOfCentralDirectoryLocator64(eocdLocator64Buffer);
byte[] eocd64Buffer = await _httpService.GetRange(info.EndOfCentralDirectoryLocator64.EndOfCentralDirectory64StartOffset, info.EndOfCentralDirectoryLocator64.EndOfCentralDirectory64StartOffset + EndOfCentralDirectory64.Size - 1);
info.EndOfCentralDirectory64 = new EndOfCentralDirectory64(eocd64Buffer);
startCD = info.EndOfCentralDirectory64.CentralDirectoryStartOffset;
endCD = info.EndOfCentralDirectory64.CentralDirectoryStartOffset + info.EndOfCentralDirectory64.CentralDirectorySize + EndOfCentralDirectory64.Size - 1;
info.CentralDirectoryEntries = info.EndOfCentralDirectory64.CentralDirectoryRecordCount;
}
else
{
startCD = info.EndOfCentralDirectory.CentralDirectoryStartOffset;
endCD = info.EndOfCentralDirectory.CentralDirectoryStartOffset + info.EndOfCentralDirectory.CentralDirectorySize + EndOfCentralDirectory.Size - 1;
info.CentralDirectoryEntries = info.EndOfCentralDirectory.CentralDirectoryRecordCount;
}
byte[] cdBuffer = await _httpService.GetRange(startCD, endCD);
info.CentralDirectory = CentralDirectoryHeader.GetFromBuffer(cdBuffer, info.CentralDirectoryEntries);
return(info);
}
private PackageEntryEntity Initialize(PackageEntryEntity entity, CentralDirectoryHeader metadata)
{
entity.Comment = metadata.Comment;
entity.CommentSize = metadata.CommentSize;
entity.CompressedSize = metadata.CompressedSize;
entity.CompressionMethod = metadata.CompressionMethod;
entity.Crc32 = metadata.Crc32;
entity.DiskNumberStart = metadata.DiskNumberStart;
entity.ExternalAttributes = metadata.ExternalAttributes;
entity.ExtraField = metadata.ExtraField;
entity.ExtraFieldSize = metadata.ExtraFieldSize;
entity.Flags = metadata.Flags;
entity.InternalAttributes = metadata.InternalAttributes;
entity.LastModifiedDate = metadata.LastModifiedDate;
entity.LastModifiedTime = metadata.LastModifiedTime;
entity.LocalHeaderOffset = metadata.LocalHeaderOffset;
entity.Name = metadata.Name;
entity.NameSize = metadata.NameSize;
entity.UncompressedSize = metadata.UncompressedSize;
entity.VersionMadeBy = metadata.VersionMadeBy;
entity.VersionToExtract = metadata.VersionToExtract;
return(entity);
}
internal override void PrepareForZip(CentralDirectoryHeader header = null)
{
base.PrepareForZip(header);
this.HeaderType = CompressedStreamHeader.None;
}
public CentralDirectoryHeaderInfo(CentralDirectoryHeader header)
: base((FileHeaderBase)header)
{
this.LocalHeaderOffsetOverflow = header.LocalHeaderOffset == uint.MaxValue;
}
// Haven't figured out how to do this without borrowing code from the Parse function - compiler wont allow yield return in a lambda.
public IEnumerator <CDEntry> GetEnumerator()
{
using (var fs = new FileStream(ZIPPath, FileMode.Open, FileAccess.Read, FileShare.Read))
{
EOCDOffset = LocateEOCD(fs);
if (EOCDOffset == 0)
{
throw new Exception("Unable to locate EOCD");
}
CDSize = fs.ParseInt32(EOCDOffset + 12);
if (!fs.GetBytes(EOCDOffset - 76, 4).SequenceEqual(SeventySixHeader))
{
Console.WriteLine("Warning: 0606 not found at EOCD-76");
}
var cdStartOffset = EOCDOffset - CDSize - 76;
fs.Seek(cdStartOffset, SeekOrigin.Begin);
CentralDirectory = new byte[CDSize];
fs.Read(CentralDirectory, 0, CDSize);
var curPos = 0;
while (curPos < CentralDirectory.Length)
{
if (!CentralDirectoryHeader.SequenceEqual(CentralDirectory.Take(4)))
{
throw new Exception("Some sort of CentralDirectory parsing issue");
}
var n = BitConverter.ToInt16(CentralDirectory, curPos + 28);
var m = BitConverter.ToInt16(CentralDirectory, curPos + 30);
var k = BitConverter.ToInt16(CentralDirectory, curPos + 32);
var cd = new CDEntry()
{
Parent = this,
RelativeOffset = curPos,
AbsoluteOffset = cdStartOffset + curPos,
Name = ASCIIEncoding.ASCII.GetString(CentralDirectory, curPos + 46, n),
LengthFileNameN = n,
LengthExtraFieldM = m,
LengthCommentK = k,
CompressionMethod = BitConverter.ToInt16(CentralDirectory, curPos + 10),
};
if (StoringEntries)
{
CDEntries.Add(cd);
}
curPos += 46 + n + m + k;
yield return(cd);
}
fs.Close();
TriggerParsingCompleted();
if (!StoringEntries)
{
CentralDirectory = null;
}
}
}
