WIP: Clsuter support (cross node delivery, leader election)

util/linger_queue_test.go

@@ -0,0 +1,90 @@
+package util_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	"heckel.io/ntfy/v2/util"
+)
+
+func TestLingerQueue_LingerFlush(t *testing.T) {
+	// Items enqueued within the linger window are emitted as a single batch when it expires
+	q := util.NewLingerQueue[int](16, 100, 0, nil, 50*time.Millisecond)
+	defer q.Close()
+	require.True(t, q.TryEnqueue(1))
+	require.True(t, q.TryEnqueue(2))
+	require.True(t, q.TryEnqueue(3))
+	start := time.Now()
+	batch := <-q.Dequeue()
+	require.Equal(t, []int{1, 2, 3}, batch)
+	require.GreaterOrEqual(t, time.Since(start), 30*time.Millisecond) // Waited out the linger
+}
+
+func TestLingerQueue_MaxBatchFlush(t *testing.T) {
+	// Hitting the count cap flushes early, before the linger expires
+	q := util.NewLingerQueue[int](16, 5, 0, nil, time.Minute)
+	defer q.Close()
+	for i := 0; i < 12; i++ {
+		require.True(t, q.TryEnqueue(i))
+	}
+	require.Len(t, <-q.Dequeue(), 5)
+	require.Len(t, <-q.Dequeue(), 5)
+	q.Close() // Flushes the remainder
+	require.Len(t, <-q.Dequeue(), 2)
+}
+
+func TestLingerQueue_SizeCapFlush(t *testing.T) {
+	// Hitting the byte cap flushes early, before count cap or linger
+	q := util.NewLingerQueue(16, 100, 10, func(s string) int { return len(s) }, time.Minute)
+	defer q.Close()
+	require.True(t, q.TryEnqueue("aaaa"))
+	require.True(t, q.TryEnqueue("bbbb"))
+	require.True(t, q.TryEnqueue("cccc")) // 12 bytes >= 10 -> flush
+	batch := <-q.Dequeue()
+	require.Equal(t, []string{"aaaa", "bbbb", "cccc"}, batch)
+}
+
+func TestLingerQueue_TryEnqueueFull(t *testing.T) {
+	// A full queue drops (returns false) instead of blocking the producer
+	q := util.NewLingerQueue[int](1, 1, 0, nil, 0)
+	defer q.Close()
+	require.True(t, q.TryEnqueue(1))                       // Taken by the batcher, blocks emitting (no consumer)
+	waitForCond(t, func() bool { return q.TryEnqueue(2) }) // Fills the buffer once slot frees
+	require.False(t, q.TryEnqueue(3))                      // Buffer full, batcher blocked -> drop
+}
+
+func TestLingerQueue_CloseFlushesAndCloses(t *testing.T) {
+	q := util.NewLingerQueue[int](16, 100, 0, nil, time.Minute)
+	require.True(t, q.TryEnqueue(1))
+	require.True(t, q.TryEnqueue(2))
+	q.Close()
+	require.Equal(t, []int{1, 2}, <-q.Dequeue()) // Remainder flushed without waiting out the linger
+	_, ok := <-q.Dequeue()
+	require.False(t, ok) // Channel closed
+	require.False(t, q.TryEnqueue(3))
+	q.Close() // Idempotent
+}
+
+func TestLingerQueue_LingerZeroImmediate(t *testing.T) {
+	q := util.NewLingerQueue[int](16, 100, 0, nil, 0)
+	defer q.Close()
+	require.True(t, q.TryEnqueue(1))
+	select {
+	case batch := <-q.Dequeue():
+		require.Contains(t, batch, 1)
+	case <-time.After(time.Second):
+		t.Fatal("expected immediate flush with zero linger")
+	}
+}
+
+func waitForCond(t *testing.T, f func() bool) {
+	t.Helper()
+	for i := 0; i < 100; i++ {
+		if f() {
+			return
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	t.Fatal("timed out waiting for condition")
+}