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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.IO;
using System.Runtime.CompilerServices;
using System.Runtime.ExceptionServices;
using System.Threading;
using System.Threading.Tasks;
namespace System.Net.Http
{
internal sealed partial class HttpConnection : IDisposable
{
private sealed class RawConnectionStream : HttpContentStream
{
public RawConnectionStream(HttpConnection connection) : base(connection)
{
if (NetEventSource.Log.IsEnabled()) NetEventSource.Info(this);
}
public sealed override bool CanRead => _connection != null;
public sealed override bool CanWrite => _connection != null;
public override int Read(Span<byte> buffer)
{
HttpConnection? connection = _connection;
if (connection == null)
{
// Response body fully consumed or the caller didn't ask for any data
return 0;
}
int bytesRead = connection.ReadBuffered(buffer);
if (bytesRead == 0 && buffer.Length != 0)
{
// We cannot reuse this connection, so close it.
_connection = null;
connection.Dispose();
}
return bytesRead;
}
[AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder<>))]
public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken)
{
CancellationHelper.ThrowIfCancellationRequested(cancellationToken);
HttpConnection? connection = _connection;
if (connection == null)
{
// Response body fully consumed
return 0;
}
ValueTask<int> readTask = connection.ReadBufferedAsync(buffer);
int bytesRead;
if (readTask.IsCompletedSuccessfully)
{
bytesRead = readTask.Result;
}
else
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
bytesRead = await readTask.ConfigureAwait(false);
}
catch (Exception exc) when (CancellationHelper.ShouldWrapInOperationCanceledException(exc, cancellationToken))
{
throw CancellationHelper.CreateOperationCanceledException(exc, cancellationToken);
}
finally
{
ctr.Dispose();
}
}
if (bytesRead == 0 && buffer.Length != 0)
{
// A cancellation request may have caused the EOF.
CancellationHelper.ThrowIfCancellationRequested(cancellationToken);
// We cannot reuse this connection, so close it.
_connection = null;
connection.Dispose();
}
return bytesRead;
}
public override Task CopyToAsync(Stream destination, int bufferSize, CancellationToken cancellationToken)
{
ValidateCopyToArguments(destination, bufferSize);
if (cancellationToken.IsCancellationRequested)
{
return Task.FromCanceled(cancellationToken);
}
HttpConnection? connection = _connection;
if (connection == null)
{
// null if response body fully consumed
return Task.CompletedTask;
}
Task copyTask = connection.CopyToUntilEofAsync(destination, async: true, bufferSize, cancellationToken);
if (copyTask.IsCompletedSuccessfully)
{
Finish(connection);
return Task.CompletedTask;
}
return CompleteCopyToAsync(copyTask, connection, cancellationToken);
}
private async Task CompleteCopyToAsync(Task copyTask, HttpConnection connection, CancellationToken cancellationToken)
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
await copyTask.ConfigureAwait(false);
}
catch (Exception exc) when (CancellationHelper.ShouldWrapInOperationCanceledException(exc, cancellationToken))
{
throw CancellationHelper.CreateOperationCanceledException(exc, cancellationToken);
}
finally
{
ctr.Dispose();
}
// If cancellation is requested and tears down the connection, it could cause the copy
// to end early but think it ended successfully. So we prioritize cancellation in this
// race condition, and if we find after the copy has completed that cancellation has
// been requested, we assume the copy completed due to cancellation and throw.
CancellationHelper.ThrowIfCancellationRequested(cancellationToken);
Finish(connection);
}
private void Finish(HttpConnection connection)
{
// We cannot reuse this connection, so close it.
connection.Dispose();
_connection = null;
}
public override void Write(ReadOnlySpan<byte> buffer)
{
HttpConnection? connection = _connection;
if (connection == null)
{
throw new IOException(SR.ObjectDisposed_StreamClosed);
}
if (buffer.Length != 0)
{
connection.WriteWithoutBuffering(buffer);
}
}
public override ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return ValueTask.FromCanceled(cancellationToken);
}
HttpConnection? connection = _connection;
if (connection == null)
{
return ValueTask.FromException(ExceptionDispatchInfo.SetCurrentStackTrace(new IOException(SR.ObjectDisposed_StreamClosed)));
}
if (buffer.Length == 0)
{
return default;
}
ValueTask writeTask = connection.WriteWithoutBufferingAsync(buffer, async: true);
return writeTask.IsCompleted ?
writeTask :
new ValueTask(WaitWithConnectionCancellationAsync(writeTask, connection, cancellationToken));
}
public override void Flush() => _connection?.Flush();
public override Task FlushAsync(CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return Task.FromCanceled(cancellationToken);
}
HttpConnection? connection = _connection;
if (connection == null)
{
return Task.CompletedTask;
}
ValueTask flushTask = connection.FlushAsync(async: true);
return flushTask.IsCompleted ?
flushTask.AsTask() :
WaitWithConnectionCancellationAsync(flushTask, connection, cancellationToken);
}
private static async Task WaitWithConnectionCancellationAsync(ValueTask task, HttpConnection connection, CancellationToken cancellationToken)
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
await task.ConfigureAwait(false);
}
catch (Exception exc) when (CancellationHelper.ShouldWrapInOperationCanceledException(exc, cancellationToken))
{
throw CancellationHelper.CreateOperationCanceledException(exc, cancellationToken);
}
finally
{
ctr.Dispose();
}
}
}
}
}
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