Kit.Core/LibExternal/Npgsql/Internal/NpgsqlWriteBuffer.Stream.cs

122 lines
4.1 KiB
C#

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
namespace Npgsql.Internal;
public sealed partial class NpgsqlWriteBuffer
{
sealed class ParameterStream : Stream
{
readonly NpgsqlWriteBuffer _buf;
bool _disposed;
internal ParameterStream(NpgsqlWriteBuffer buf)
=> _buf = buf;
internal void Init()
=> _disposed = false;
public override bool CanRead => false;
public override bool CanWrite => true;
public override bool CanSeek => false;
public override long Length => throw new NotSupportedException();
public override void SetLength(long value)
=> throw new NotSupportedException();
public override long Position
{
get => throw new NotSupportedException();
set => throw new NotSupportedException();
}
public override long Seek(long offset, SeekOrigin origin)
=> throw new NotSupportedException();
public override void Flush()
=> CheckDisposed();
public override Task FlushAsync(CancellationToken cancellationToken = default)
{
CheckDisposed();
return cancellationToken.IsCancellationRequested
? Task.FromCanceled(cancellationToken) : Task.CompletedTask;
}
public override int Read(byte[] buffer, int offset, int count)
=> throw new NotSupportedException();
public override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken = default)
=> throw new NotSupportedException();
public override void Write(byte[] buffer, int offset, int count)
=> Write(buffer, offset, count, false);
public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken = default)
{
using (NoSynchronizationContextScope.Enter())
return Write(buffer, offset, count, true, cancellationToken);
}
Task Write(byte[] buffer, int offset, int count, bool async, CancellationToken cancellationToken = default)
{
CheckDisposed();
if (buffer == null)
throw new ArgumentNullException(nameof(buffer));
if (offset < 0)
throw new ArgumentNullException(nameof(offset));
if (count < 0)
throw new ArgumentNullException(nameof(count));
if (buffer.Length - offset < count)
throw new ArgumentException("Offset and length were out of bounds for the array or count is greater than the number of elements from index to the end of the source collection.");
if (cancellationToken.IsCancellationRequested)
return Task.FromCanceled(cancellationToken);
while (count > 0)
{
var left = _buf.WriteSpaceLeft;
if (left == 0)
return WriteLong(buffer, offset, count, async, cancellationToken);
var slice = Math.Min(count, left);
_buf.WriteBytes(buffer, offset, slice);
offset += slice;
count -= slice;
}
return Task.CompletedTask;
}
async Task WriteLong(byte[] buffer, int offset, int count, bool async, CancellationToken cancellationToken = default)
{
while (count > 0)
{
var left = _buf.WriteSpaceLeft;
if (left == 0)
{
await _buf.Flush(async, cancellationToken);
continue;
}
var slice = Math.Min(count, left);
_buf.WriteBytes(buffer, offset, slice);
offset += slice;
count -= slice;
}
}
void CheckDisposed()
{
if (_disposed)
throw new ObjectDisposedException(null);
}
protected override void Dispose(bool disposing)
=> _disposed = true;
}
}