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jellyfin/Jellyfin.Api/Helpers/ProgressiveFileCopier.cs

85 lines
3.1 KiB

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using MediaBrowser.Controller.Library;
using MediaBrowser.Model.IO;
namespace Jellyfin.Api.Helpers
{
/// <summary>
/// Progressive file copier.
/// </summary>
public class ProgressiveFileCopier
{
private readonly string? _path;
private readonly IDirectStreamProvider? _directStreamProvider;
private readonly IStreamHelper _streamHelper;
/// <summary>
/// Initializes a new instance of the <see cref="ProgressiveFileCopier"/> class.
/// </summary>
/// <param name="streamHelper">Instance of the <see cref="IStreamHelper"/> interface.</param>
/// <param name="path">Filepath to stream from.</param>
public ProgressiveFileCopier(IStreamHelper streamHelper, string path)
{
_path = path;
_streamHelper = streamHelper;
_directStreamProvider = null;
}
/// <summary>
/// Initializes a new instance of the <see cref="ProgressiveFileCopier"/> class.
/// </summary>
/// <param name="streamHelper">Instance of the <see cref="IStreamHelper"/> interface.</param>
/// <param name="directStreamProvider">Instance of the <see cref="IDirectStreamProvider"/> interface.</param>
public ProgressiveFileCopier(IStreamHelper streamHelper, IDirectStreamProvider directStreamProvider)
{
_directStreamProvider = directStreamProvider;
_streamHelper = streamHelper;
_path = null;
}
/// <summary>
/// Write source stream to output.
/// </summary>
/// <param name="outputStream">Output stream.</param>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>A <see cref="Task"/>.</returns>
public async Task WriteToAsync(Stream outputStream, CancellationToken cancellationToken)
{
if (_directStreamProvider != null)
{
await _directStreamProvider.CopyToAsync(outputStream, cancellationToken).ConfigureAwait(false);
return;
}
var fileOptions = FileOptions.SequentialScan;
// use non-async filestream along with read due to https://github.com/dotnet/corefx/issues/6039
if (Environment.OSVersion.Platform != PlatformID.Win32NT)
{
fileOptions |= FileOptions.Asynchronous;
}
await using var inputStream = new FileStream(_path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, 4096, fileOptions);
const int emptyReadLimit = 100;
var eofCount = 0;
while (eofCount < emptyReadLimit)
{
var bytesRead = await _streamHelper.CopyToAsync(inputStream, outputStream, cancellationToken).ConfigureAwait(false);
if (bytesRead == 0)
{
eofCount++;
await Task.Delay(100, cancellationToken).ConfigureAwait(false);
}
else
{
eofCount = 0;
}
}
}
}
}