Json parsing

src/pdns-dhcp/PowerDns/PowerDnsHandler.cs

@@ -1,11 +1,78 @@
+using System.Buffers;
+using System.Text.Json;
+
 using Microsoft.AspNetCore.Connections;
+using Microsoft.Toolkit.HighPerformance;
+using Microsoft.Toolkit.HighPerformance.Buffers;
 
 namespace pdns_dhcp.PowerDns;
 
 public class PowerDnsHandler : ConnectionHandler
 {
-	public override Task OnConnectedAsync(ConnectionContext connection)
+	public override async Task OnConnectedAsync(ConnectionContext connection)
 	{
-		return Task.CompletedTask;
+		var input = connection.Transport.Input;
+		JsonReaderState state = default;
+		using ArrayPoolBufferWriter<byte> json = new();
+		using ArrayPoolBufferWriter<byte> buffer = new();
+		while (!connection.ConnectionClosed.IsCancellationRequested)
+		{
+			var read = await input.ReadAsync(connection.ConnectionClosed).ConfigureAwait(false);
+			if (read.IsCanceled)
+			{
+				return;
+			}
+
+			foreach (var memory in read.Buffer)
+			{
+				buffer.Write(memory.Span);
+				if (ConsumeJson(buffer, json, ref state))
+				{
+					var method = JsonSerializer.Deserialize<Method>(json.WrittenSpan);
+					json.Clear();
+					state = default;
+				}
+			}
+
+			input.AdvanceTo(read.Buffer.End);
+		}
+
+		static bool ConsumeJson(ArrayPoolBufferWriter<byte> inflight, ArrayPoolBufferWriter<byte> json, ref JsonReaderState state)
+		{
+			bool final = false;
+			Utf8JsonReader reader = new(inflight.WrittenSpan, false, state);
+			while (!final && reader.Read())
+			{
+				if (reader.TokenType == JsonTokenType.EndObject && reader.CurrentDepth == 0)
+				{
+					final = true;
+				}
+			}
+
+			state = reader.CurrentState;
+			int consumed = (int)reader.BytesConsumed;
+			if (consumed > 0)
+			{
+				json.Write(inflight.WrittenSpan[..consumed]);
+
+				Span<byte> buffer = default;
+				var remaining = inflight.WrittenCount - consumed;
+				if (remaining > 0)
+				{
+					buffer = inflight.GetSpan(remaining)[..remaining];
+					inflight.WrittenSpan[consumed..].CopyTo(buffer);
+				}
+
+				// clear only clears up until WrittenCount
+				// thus data after write-head is safe
+				inflight.Clear();
+				if (!buffer.IsEmpty)
+				{
+					inflight.Write(buffer);
+				}
+			}
+
+			return final;
+		}
 	}
 }

src/pdns-dhcp/pdns-dhcp.csproj

@@ -18,8 +18,8 @@
 		<PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.0" />
 		<PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.0" />
 		<PackageReference Include="Sep" Version="0.3.0" />
-		<PackageReference Include="Stl.Generators" Version="6.7.21" />
+		<PackageReference Include="Stl.Generators" Version="6.8.11" />
-		<PackageReference Include="Stl.Interception" Version="6.7.21" />
+		<PackageReference Include="Stl.Interception" Version="6.8.11" />
 		<PackageReference Include="System.IO.Pipelines" Version="8.0.0" />
 	</ItemGroup>