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osu-lazer/osu.Game/IO/Archives/MemoryStreamArchiveReader.cs
Bartłomiej Dach e57d7d1205
Fix MemoryStreamArchiveReader.GetStream() failing in some cases
`MemoryStreamArchiveReader` introduced in
0657b55196 would previously use
`MemoryStream.GetBuffer()` to retrieve the underlying byte buffer with
stream data. However, this is not generally the method you would want,
for two reasons:

1. It can fail if the stream wasn't created in the way that supports it.
2. As per

	https://learn.microsoft.com/en-us/dotnet/api/system.io.memorystream.getbuffer?view=net-7.0#system-io-memorystream-getbuffer,

   it will return the _raw_ contents of the buffer, including
   potentially unused bytes.

To fix, use `MemoryStream.ToArray()` instead, which avoids both
pitfalls. Notably, `ToArray()` always returns the full contents of the
buffer, regardless of `Position`, as documented in:

    https://learn.microsoft.com/en-us/dotnet/api/system.io.memorystream.toarray?view=net-7.0#system-io-memorystream-toarray
2023-09-18 11:50:36 +02:00

31 lines
875 B
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System.Collections.Generic;
using System.IO;
namespace osu.Game.IO.Archives
{
/// <summary>
/// Allows reading a single file from the provided memory stream.
/// </summary>
public class MemoryStreamArchiveReader : ArchiveReader
{
private readonly MemoryStream stream;
public MemoryStreamArchiveReader(MemoryStream stream, string filename)
: base(filename)
{
this.stream = stream;
}
public override Stream GetStream(string name) => new MemoryStream(stream.ToArray(), 0, (int)stream.Length);
public override void Dispose()
{
}
public override IEnumerable<string> Filenames => new[] { Name };
}
}