// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
namespace System.IO
{
/// Provides methods to help in the implementation of Stream-derived types.
internal static partial class StreamHelpers
{
/// Validate the arguments to CopyTo, as would Stream.CopyTo.
public static void ValidateCopyToArgs(Stream source, Stream destination, int bufferSize)
{
if (destination == null)
{
throw new ArgumentNullException(nameof(destination));
}
if (bufferSize <= 0)
{
throw new ArgumentOutOfRangeException(nameof(bufferSize), bufferSize, Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
}
bool sourceCanRead = source.CanRead;
if (!sourceCanRead && !source.CanWrite)
{
throw new ObjectDisposedException(null, Environment.GetResourceString("ObjectDisposed_StreamClosed"));
}
bool destinationCanWrite = destination.CanWrite;
if (!destinationCanWrite && !destination.CanRead)
{
throw new ObjectDisposedException(nameof(destination), Environment.GetResourceString("ObjectDisposed_StreamClosed"));
}
if (!sourceCanRead)
{
throw new NotSupportedException(Environment.GetResourceString("NotSupported_UnreadableStream"));
}
if (!destinationCanWrite)
{
throw new NotSupportedException(Environment.GetResourceString("NotSupported_UnwritableStream"));
}
}
}
}