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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.Diagnostics;
using System.Runtime.InteropServices;
namespace System.IO
{
// Provides the platform-agnostic functionality for streams used as console input and output.
// Platform-specific implementations derive from ConsoleStream to implement Read and Write
// (and optionally Flush), as well as any additional ctor/Dispose logic necessary.
internal abstract class ConsoleStream : Stream
{
private bool _canRead, _canWrite;
internal ConsoleStream(FileAccess access)
{
Debug.Assert(access == FileAccess.Read || access == FileAccess.Write);
_canRead = ((access & FileAccess.Read) == FileAccess.Read);
_canWrite = ((access & FileAccess.Write) == FileAccess.Write);
}
public override void Write(byte[] buffer, int offset, int count)
{
ValidateWrite(buffer, offset, count);
Write(new ReadOnlySpan<byte>(buffer, offset, count));
}
public override void WriteByte(byte value) => Write(new ReadOnlySpan<byte>(in value));
public override int Read(byte[] buffer, int offset, int count)
{
ValidateRead(buffer, offset, count);
return Read(new Span<byte>(buffer, offset, count));
}
public override int ReadByte()
{
byte b = 0;
int result = Read(new Span<byte>(ref b));
return result != 0 ? b : -1;
}
protected override void Dispose(bool disposing)
{
_canRead = false;
_canWrite = false;
base.Dispose(disposing);
}
public sealed override bool CanRead => _canRead;
public sealed override bool CanWrite => _canWrite;
public sealed override bool CanSeek => false;
public sealed override long Length => throw Error.GetSeekNotSupported();
public sealed override long Position
{
get => throw Error.GetSeekNotSupported();
set => throw Error.GetSeekNotSupported();
}
public override void Flush() { }
public sealed override void SetLength(long value) => throw Error.GetSeekNotSupported();
public sealed override long Seek(long offset, SeekOrigin origin) => throw Error.GetSeekNotSupported();
protected void ValidateRead(byte[] buffer, int offset, int count)
{
ValidateBufferArguments(buffer, offset, count);
if (!_canRead)
{
throw Error.GetReadNotSupported();
}
}
protected void ValidateWrite(byte[] buffer, int offset, int count)
{
ValidateBufferArguments(buffer, offset, count);
if (!_canWrite)
{
throw Error.GetWriteNotSupported();
}
}
}
}
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