dev-npgsql/npgsql: Npgsql is the .NET data provider for PostgreSQL.

src/Npgsql/Shims/StreamExtensions.cs
71 строка2 KB
Shay Rojansky
Implementation of the ADO.NET batching API (#3860)
16 авг 2021, 14:08
16 авг 2021, 14:080d8dd34
#if NETSTANDARD2_0
using System.Buffers;
using System.Threading;
using System.Threading.Tasks;

// ReSharper disable once CheckNamespace
namespace System.IO
{
    // Helpers to read/write Span/Memory<byte> to Stream before netstandard 2.1
    static class StreamExtensions
    {
        public static int Read(this Stream stream, Span<byte> buffer)
        {
            var sharedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
            try
            {
                var numRead = stream.Read(sharedBuffer, 0, buffer.Length);
                new Span<byte>(sharedBuffer, 0, numRead).CopyTo(buffer);
                return numRead;
            }
            finally
            {
                ArrayPool<byte>.Shared.Return(sharedBuffer);
            }
        }

        public static async ValueTask<int> ReadAsync(this Stream stream, Memory<byte> buffer, CancellationToken cancellationToken = default)
        {
            var sharedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
            try
            {
                var result = await stream.ReadAsync(sharedBuffer, 0, buffer.Length, cancellationToken);
                new Span<byte>(sharedBuffer, 0, result).CopyTo(buffer.Span);
                return result;
            }
            finally
            {
                ArrayPool<byte>.Shared.Return(sharedBuffer);
            }
        }

        public static void Write(this Stream stream, ReadOnlySpan<byte> buffer)
        {
            var sharedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
            try
            {
                buffer.CopyTo(sharedBuffer);
                stream.Write(sharedBuffer, 0, buffer.Length);
            }
            finally
            {
                ArrayPool<byte>.Shared.Return(sharedBuffer);
            }
        }

        public static async ValueTask WriteAsync(this Stream stream, ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
        {
            var sharedBuffer = ArrayPool<byte>.Shared.Rent(buffer.Length);
            buffer.Span.CopyTo(sharedBuffer);
            try
            {
                await stream.WriteAsync(sharedBuffer, 0, buffer.Length, cancellationToken);
            }
            finally
            {
                ArrayPool<byte>.Shared.Return(sharedBuffer);
            }
        }
    }
}
#endif