public async Task AllowsReadingOfZipCentralDirectory(string path)
{
// Arrange
var originalStream = TestUtility.BufferTestData(path);
var result = await TestUtility.ReadWithMiniZipAsync(originalStream);
var expected = result.Data;
var innerStream = new MemoryStream();
var virtualOffset = (long)(expected.Zip64?.OffsetOfCentralDirectory ?? expected.OffsetOfCentralDirectory);
originalStream.Position = virtualOffset;
await originalStream.CopyToAsync(innerStream);
var target = new VirtualOffsetStream(innerStream, virtualOffset);
var reader = new ZipDirectoryReader(target);
var expectedSize = originalStream.Length - virtualOffset;
// Act
var actual = await reader.ReadAsync();
// Assert
TestUtility.VerifyJsonEquals(expected, actual);
Assert.Equal(expectedSize, innerStream.Length);
Assert.Equal(originalStream.Length, target.Length);
}
public Facts()
{
_bytes = new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
_innerStream = new MemoryStream(_bytes);
_virtualOffset = 20;
_target = new VirtualOffsetStream(_innerStream, _virtualOffset);
}
/// <summary>
/// Wraps the provided <paramref name="srcStream"/> (which should be a stream written by
/// <see cref="WriteAsync(Stream, Stream)"/>) in a virtual stream readable by most ZIP archive readers. For
/// example, you can use <see cref="ZipDirectoryReader"/> to read the returned stream. The returned stream does
/// not contain ZIP file entry contents and only contains the central directory.
/// </summary>
/// <param name="srcStream">The stream containing the "MZIP" format.</param>
/// <returns>A stream readable as a ZIP archive with a central directory but no entries.</returns>
public Task <Stream> ReadAsync(Stream srcStream)
{
using (var binaryReader = new BinaryReader(srcStream, Encoding.ASCII, leaveOpen: true))
{
// First, read the offset of the central directory.
var virtualOffset = (long)binaryReader.ReadUInt64();
// Next, wrap the rest of the stream as if it was at the end of the full ZIP file.
var boundedStream = new BoundedStream(srcStream, srcStream.Position, srcStream.Length - 1);
var outputStream = new VirtualOffsetStream(boundedStream, virtualOffset);
return(Task.FromResult <Stream>(outputStream));
}
}
