V14

core/cmd/dragontcp-client/chunk_test.go

@@ -23,6 +23,76 @@ func TestAdaptiveSizerRecoversFromMinimum(t *testing.T) {
 	}
 }
 
+func newTestConn(min, max int) *chunkConn {
+	return &chunkConn{pipeline: max, minPipeline: min, maxPipeline: max}
+}
+
+func TestPinnedBatchNeverAdapts(t *testing.T) {
+	c := newTestConn(5, 5)
+	if got := c.batchCount(1400); got != 5 {
+		t.Fatalf("pinned batch should request 5 records, got %d", got)
+	}
+	for i := 0; i < 10; i++ {
+		if _, _, shrank := c.shrinkPipeline(); shrank {
+			t.Fatal("pinned batch shrank on transport failure")
+		}
+		c.growPipeline()
+	}
+	if c.pipeline != 5 {
+		t.Fatalf("pinned batch drifted to %d", c.pipeline)
+	}
+	if got := c.batchCount(1400); got != 5 {
+		t.Fatalf("pinned batch should still request 5 records, got %d", got)
+	}
+}
+
+func TestPinnedBatchSurvivesOneMiBCap(t *testing.T) {
+	// 8 x 1 MiB records exceed the ~1 MiB useful-data cap. A pinned depth must
+	// win anyway, otherwise a path that needs exactly 8 records is broken by
+	// an unrelated size heuristic.
+	c := newTestConn(8, 8)
+	if got := c.batchCount(1024 * 1024); got != 8 {
+		t.Fatalf("pinned batch should ignore the 1 MiB cap, got %d", got)
+	}
+	// An unpinned batch is still capped.
+	c = newTestConn(1, 8)
+	if got := c.batchCount(1024 * 1024); got != 1 {
+		t.Fatalf("unpinned batch should be capped to 1, got %d", got)
+	}
+}
+
+func TestAdaptiveBatchStopsAtFloor(t *testing.T) {
+	c := newTestConn(4, 32)
+	seen := map[int]bool{}
+	for i := 0; i < 12; i++ {
+		_, next, _ := c.shrinkPipeline()
+		seen[next] = true
+	}
+	if c.pipeline != 4 {
+		t.Fatalf("batch fell to %d, want the floor 4", c.pipeline)
+	}
+	if !seen[16] || !seen[8] {
+		t.Fatalf("expected halving through 16 and 8, saw %v", seen)
+	}
+	for i := 0; i < 100; i++ {
+		c.growPipeline()
+	}
+	if c.pipeline != 32 {
+		t.Fatalf("batch grew to %d, want the ceiling 32", c.pipeline)
+	}
+}
+
+func TestSingleBatchIsFixed(t *testing.T) {
+	c := newTestConn(1, 1)
+	if !c.pinnedBatch() {
+		t.Fatal("a 1..1 batch must be treated as pinned")
+	}
+	c.growPipeline()
+	if c.pipeline != 1 {
+		t.Fatalf("batch of 1 grew to %d", c.pipeline)
+	}
+}
+
 func TestReconnectZeroMeansPersistent(t *testing.T) {
 	lane := newRequestLane("127.0.0.1:1", 0, 0, 0)
 	if lane.reconnectEvery != 0 {