/// <summary>
/// Returns a list of all filenames in the remote .zip archive
/// </summary>
/// <param name="archiveUrl">URL of the .zip archive</param>
/// <returns>List of filenames</returns>
public static async Task <IEnumerable <string> > GetFileList(string archiveUrl)
{
PartialZipDownloader downloader = new PartialZipDownloader(archiveUrl);
PartialZipInfo info = await downloader.Open();
return(info.CentralDirectory.Select(cd => cd.FileName).OrderBy(f => f));
}
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.");
}
/// <summary>
/// Downloads a specific file from a remote .zip archive
/// </summary>
/// <param name="archiveUrl">URL of the .zip archive</param>
/// <param name="filePath">Path of the file</param>
/// <returns>File content</returns>
public static async Task <byte[]> DownloadFile(string archiveUrl, string filePath)
{
PartialZipDownloader downloader = new PartialZipDownloader(archiveUrl);
PartialZipInfo info = await downloader.Open();
byte[] content = await downloader.Download(info, filePath);
return(content);
}
/// <summary>
/// Downloads a specific file from a remote .zip archive
/// </summary>
/// <param name="archiveUrl">URL of the .zip archive</param>
/// <param name="filePath">Path of the file in archive</param>
/// <param name="writePath">Path where the file will be written</param>
/// <param name="preserveTime">Preserve modification date</param>
/// <returns>File content</returns>
public static async Task DownloadFile(string archiveUrl, string filePath, string writePath)
{
PartialZipDownloader downloader = new PartialZipDownloader(archiveUrl);
PartialZipInfo info = await downloader.Open();
var content = await downloader.Download(info, filePath);
File.WriteAllBytes(writePath, content.Item1);
File.SetLastWriteTimeUtc(writePath, content.Item2);
}
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);
}
