measurement: name the kinds by protocol and action, add the http_request kind and QUIC settings

backend/shared/tests/MoShiro.Measurement.Tests/QuicSettingsTests.cs

@@ -0,0 +1,57 @@
+using System.Net;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using Fleet.Core;
+
+namespace MoShiro.Measurement.Tests;
+
+public sealed class QuicSettingsTests
+{
+    [Theory]
+    [InlineData(1100, null, false)]
+    [InlineData(null, 70_000, false)]
+    [InlineData(1400, 1300, false)]
+    [InlineData(1280, 1500, true)]
+    [InlineData(null, null, true)]
+    public void Validate_RejectsMtuOutsideTheSupportedRangeOrOutOfOrder(int? min, int? max, bool valid) =>
+        Assert.Equal(valid, new QuicSettings { MinMtu = min, MaxMtu = max }.Validate() is null);
+
+    /// <summary>设置真的写进了 MsQuic：最大 MTU 压低后数据报上限随之变小，最小 MTU 抬高后一连上就是大包（不用等路径探测）。</summary>
+    [Theory]
+    [InlineData(1200, 1280, 1200, 1280)]
+    [InlineData(1500, 1500, 1400, 1500)]
+    public async Task Settings_ChangeTheDatagramLimitOfTheConnection(int min, int max, int atLeast, int atMost)
+    {
+        var settings = new QuicSettings { MinMtu = min, MaxMtu = max };
+        var log = new NullLog();
+        using ECDsa key = ECDsa.Create(ECCurve.NamedCurves.nistP256);
+        var request = new CertificateRequest("CN=localhost", key, HashAlgorithmName.SHA256);
+        using X509Certificate2 certificate = request.CreateSelfSigned(DateTimeOffset.UnixEpoch, DateTimeOffset.UnixEpoch.AddYears(100));
+        await using var listener = new MsQuicListener(IPAddress.Loopback, [0], certificate, (_, _) => { }, log, null, settings);
+        listener.Start();
+        using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(15));
+        MsQuicConnection client = await MsQuicConnection.ConnectAsync(IPAddress.Loopback, listener.BoundPorts[0], 0, key.ExportSubjectPublicKeyInfo(), (_, _) => { }, log, timeout.Token, settings);
+        try
+        {
+            while (!client.IsReady)
+            {
+                await Task.Delay(10, timeout.Token);
+            }
+
+            // 路径 MTU 探测还可能在往上走，给它一点时间；上限始终不能超过设置的最大 MTU
+            await Task.Delay(1500, timeout.Token);
+            Assert.InRange(client.MaxDatagramBytes, atLeast - 100, atMost);
+        }
+        finally
+        {
+            await client.DisposeAsync().AsTask().WaitAsync(TimeSpan.FromSeconds(3));
+        }
+    }
+
+    private sealed class NullLog : INodeLog
+    {
+        public void Write(NodeLogLevel level, string message, params (string Key, object? Value)[] fields)
+        {
+        }
+    }
+}