perf(worker): launcher-configurable event queue capacity

2026-08-15 17:10:54 -04:00
parent f3e1de5f37
commit 13583322b5
10 changed files with 253 additions and 5 deletions
@@ -419,6 +419,75 @@ public sealed class MxAccessEventQueueTests
        await Assert.ThrowsAnyAsync<OperationCanceledException>(async () => await wait);
    }

+    /// <summary>
+    ///     The queue capacity comes from the launcher-set environment variable;
+    ///     a missing, unparseable, below-floor, or above-ceiling value must fall
+    ///     back to the 10,000 default rather than throw. A bad environment value
+    ///     must never stop the worker's session from starting.
+    /// </summary>
+    /// <param name="environmentValue">Raw environment value under test.</param>
+    /// <param name="expected">Expected resolved capacity.</param>
+    [Theory]
+    [InlineData(null, MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("not-a-number", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("0", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("-5", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("999", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("1000001", MxAccessEventQueue.DefaultCapacity)]
+    [InlineData("1000", 1000)]
+    [InlineData("1000000", 1000000)]
+    [InlineData("50000", 50000)]
+    public void ResolveCapacity_WithEnvironmentValue_FallsBackToDefaultWhenUnusable(
+        string? environmentValue,
+        int expected)
+    {
+        string? original = Environment.GetEnvironmentVariable(
+            MxAccessEventQueue.CapacityEnvironmentVariableName);
+        try
+        {
+            Environment.SetEnvironmentVariable(
+                MxAccessEventQueue.CapacityEnvironmentVariableName,
+                environmentValue);
+
+            Assert.Equal(expected, MxAccessEventQueue.ResolveCapacity());
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable(
+                MxAccessEventQueue.CapacityEnvironmentVariableName,
+                original);
+        }
+    }
+
+    /// <summary>
+    ///     A resolved capacity is what the queue is actually built with, so the
+    ///     configured headroom reaches the overflow check rather than only the
+    ///     resolver.
+    /// </summary>
+    [Fact]
+    public void Constructor_WithResolvedCapacity_UsesEnvironmentValue()
+    {
+        string? original = Environment.GetEnvironmentVariable(
+            MxAccessEventQueue.CapacityEnvironmentVariableName);
+        try
+        {
+            Environment.SetEnvironmentVariable(
+                MxAccessEventQueue.CapacityEnvironmentVariableName,
+                "2500");
+
+            MxAccessEventQueue queue = new(MxAccessEventQueue.ResolveCapacity());
+
+            Assert.Equal(2500, queue.Capacity);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable(
+                MxAccessEventQueue.CapacityEnvironmentVariableName,
+                original);
+        }
+    }
+
    // Mirrors MxAccessEventQueue's per-event repeated-field allowance. Kept local rather than made
    // public on the queue: the byte-budget tests state their budgets in units of that charge, so a
    // change to it should surface here as a failing bound instead of silently moving with the code.