feat: add system.buffers support for pipe target

src/process.tests/PipingTests.cs

@@ -1,8 +1,9 @@
 // Copyright (c) The Geekeey Authors
 // SPDX-License-Identifier: EUPL-1.2
 
-using System.Text;
+using System.Buffers;
 using System.IO.Pipelines;
+using System.Text;
 
 using Geekeey.Process.Buffered;
 
@@ -619,6 +620,19 @@ internal sealed class PipingTests
 		await Assert.That(output.Length).IsEqualTo(100_000);
 	}
 
+	[Test]
+	public async Task I_can_execute_a_command_and_pipe_the_stdout_to_a_buffer_writer()
+	{
+		var output = new ArrayBufferWriter<byte>();
+		var cmd = new Command(Testing.Fixture.Program.FilePath)
+				  .WithArguments(["generate", "blob", "--length", "100000"]) |
+			  PipeTarget.ToBufferWriter(output);
+
+		await cmd.ExecuteAsync();
+
+		await Assert.That(output.WrittenCount).IsEqualTo(100_000);
+	}
+
 	[Test]
 	public async Task I_can_execute_a_command_and_pipe_the_stdout_into_multiple_hierarchical_targets()
 	{

src/process/PipeSource.cs

@@ -1,8 +1,8 @@
 // Copyright (c) The Geekeey Authors
 // SPDX-License-Identifier: EUPL-1.2
 
-using System.Text;
 using System.IO.Pipelines;
+using System.Text;
 
 namespace Geekeey.Process;
 

src/process/PipeTarget.cs

@@ -195,6 +195,29 @@ public partial class PipeTarget
 		});
 	}
 
+	/// <summary>
+	/// Creates a pipe target that writes to the specified buffer writer.
+	/// </summary>
+	public static PipeTarget ToBufferWriter(IBufferWriter<byte> writer)
+	{
+		return Create(async (origin, cancellationToken) =>
+		{
+			using var buffer = MemoryPool<byte>.Shared.Rent(MemoryBufferStream.DefaultBufferSize);
+
+			while (true)
+			{
+				var read = await origin.ReadAsync(buffer.Memory, cancellationToken);
+				if (read <= 0)
+				{
+					break;
+				}
+
+				buffer.Memory[..read].Span.CopyTo(writer.GetSpan(read));
+				writer.Advance(read);
+			}
+		});
+	}
+
 	/// <summary>
 	/// Creates a pipe target that writes to the specified file.
 	/// </summary>