/// <summary>
/// Creates an instance of <see cref="ICompressedArchiveAccess"/> that can be used to access a nested archive.
/// </summary>
/// <param name="parentArchiveAccess">The parent archive, which contains the nested archive indicated by <paramref name="entry"/>.</param>
/// <param name="entry">The entry within <paramref name="parentArchiveAccess"/> that indicates a nested archive.</param>
/// <returns>An instance of <see cref="NestedCompressedArchiveAccess"/>, which provides access to the nested archive.</returns>
/// <remarks>This wrapper type takes care of cleaning up any temporary files that may be required to access the nested archive.
/// For example, some data streams used to access an archive are not navigable from the parent stream (GZIP).</remarks>
public static NestedCompressedArchiveAccess Create(ICompressedArchiveAccess parentArchiveAccess, ICompressedArchiveEntry entry)
{
NestedCompressedArchiveAccess nestedCompressedArchive = null;
var entryName = entry.Name;
var nestedArchiveFormats = Path.GetExtension(entryName).GetCompressedArchiveFormatsFromFileExtension();
var nestedArchiveFormat = nestedArchiveFormats.FirstOrDefault();
if (nestedArchiveFormat.IsCompressedArchiveFormatSupported())
{
TemporaryDirectory temporaryLocation = null;
var entryData = parentArchiveAccess.OpenEntry(entry);
if (FormatMustBeExtracted(parentArchiveAccess.Format) || FormatMustBeExtracted(nestedArchiveFormat))
{
// We can't fully navigate the nested stream, so extract to disk, then proceed.
temporaryLocation = new TemporaryDirectory();
var temporaryEntryFilePath = Path.Combine(temporaryLocation.Path, entryName);
if (Directory.CreateDirectory(Path.GetDirectoryName(temporaryEntryFilePath)).Exists)
{
System.Diagnostics.Debug.WriteLine("Extracted entry " + entryName + " to " + temporaryLocation.Path);
var fileStream = new FileStream(temporaryEntryFilePath, FileMode.Create, FileAccess.ReadWrite);
entryData.CopyTo(fileStream);
fileStream.Seek(0, SeekOrigin.Begin);
entryData.Dispose();
entryData = fileStream;
}
}
var compressedArchive = CompressedArchiveAccess.Open(entryData, nestedArchiveFormat, CompressedArchiveAccessMode.Read);
nestedCompressedArchive = new NestedCompressedArchiveAccess(parentArchiveAccess, compressedArchive, temporaryLocation);
nestedCompressedArchive.NestedArchiveFormats = nestedArchiveFormats;
}
return(nestedCompressedArchive);
}
private static NestedCompressedArchiveAccess GetNestedCompressedArchive(ICompressedArchiveAccess compressedArchiveAccess, string locationInArchive, ref string nestedArchiveLocation)
{
var nestedArchiveLocations = locationInArchive.GetNestedContainerLocations();
var entryName = nestedArchiveLocations.First();
if (string.IsNullOrEmpty(nestedArchiveLocation))
{
nestedArchiveLocation = entryName + '/';
}
else
{
nestedArchiveLocation += entryName + '/';
}
var nestedArchiveEntry = compressedArchiveAccess.Entries.FirstOrDefault(e => e.Name.NormalizePathSeparators() == entryName);
NestedCompressedArchiveAccess nestedCompressedArchive = null;
if (nestedArchiveEntry != null)
{
nestedCompressedArchive = NestedCompressedArchiveAccess.Create(compressedArchiveAccess, nestedArchiveEntry);
if (nestedCompressedArchive != null)
{
// If there is more than one nested archive format on the location, e.g. it's a .tar.gz, or if we did not consume the entire location
// in the archive, then we need to recurse into this newly located archive to get to the ultimate nested archive.
if ((nestedCompressedArchive.NestedArchiveFormats.Count() > 1) || (nestedArchiveLocations.Length > 1))
{
locationInArchive = string.Join("/", nestedArchiveLocations, 1, nestedArchiveLocations.Length - 1) + '/';
if (locationInArchive.IsInNestedContainer())
{
nestedCompressedArchive = GetNestedCompressedArchive(nestedCompressedArchive, locationInArchive, ref nestedArchiveLocation);
}
}
}
}
return(nestedCompressedArchive);
}
