feat: add syscall aggregate sampling infrastructure (task 17)

1 files changed, 57 insertions, 0 deletions

diff --git a/internal/statsengine/aggregate_test.go b/internal/statsengine/aggregate_test.go
new file mode 100644
index 0000000..0d11214
--- /dev/null
+++ b/internal/statsengine/aggregate_test.go
@@ -0,0 +1,57 @@
+package statsengine
+
+import (
+	"testing"
+
+	"ior/internal/types"
+)
+
+func TestIngestSyscallAggregatesUpdatesSnapshot(t *testing.T) {
+	engine := NewEngine(DefaultTopN)
+	engine.IngestSyscallAggregates([]SyscallAggregate{
+		{
+			TraceID:        types.SYS_ENTER_FUTEX,
+			Count:          3,
+			Errors:         1,
+			TotalLatencyNs: 90,
+			MinLatencyNs:   10,
+			MaxLatencyNs:   50,
+			LatencyHistogramNs: [8]uint64{
+				1, 1, 1, 0, 0, 0, 0, 0,
+			},
+		},
+	})
+
+	snap, err := engine.Snapshot()
+	if err != nil {
+		t.Fatalf("snapshot error: %v", err)
+	}
+	if snap.TotalSyscalls != 3 {
+		t.Fatalf("TotalSyscalls = %d, want 3", snap.TotalSyscalls)
+	}
+	if snap.TotalErrors != 1 {
+		t.Fatalf("TotalErrors = %d, want 1", snap.TotalErrors)
+	}
+	if snap.LatencyHistogram.Total != 3 {
+		t.Fatalf("LatencyHistogram.Total = %d, want 3", snap.LatencyHistogram.Total)
+	}
+
+	syscalls := snap.Syscalls()
+	var futexRow *SyscallSnapshot
+	for i := range syscalls {
+		row := &syscalls[i]
+		if row.TraceID == types.SYS_ENTER_FUTEX {
+			futexRow = row
+			break
+		}
+	}
+	if futexRow == nil {
+		t.Fatal("expected futex syscall row")
+	}
+	if futexRow.Count != 3 || futexRow.Errors != 1 {
+		t.Fatalf("futex row = %+v, want count=3 errors=1", *futexRow)
+	}
+	if futexRow.LatencyMinNs != 10 || futexRow.LatencyMaxNs != 50 {
+		t.Fatalf("futex min/max = %d/%d, want 10/50", futexRow.LatencyMinNs, futexRow.LatencyMaxNs)
+	}
+}