Reduce to a single code path through sendBatches regardless of limit (#6216)

* Reduce to a single code path through sendBatches regardless of limit specified

* simplify sendBatches by using -1 to specify no limit

* test fix

pkg/ingester/ingester.go

@@ -615,7 +615,13 @@ func (i *Ingester) Query(req *logproto.QueryRequest, queryServer logproto.Querie
 
 	defer errUtil.LogErrorWithContext(ctx, "closing iterator", it.Close)
 
-	return sendBatches(ctx, it, queryServer, req.Limit)
+	// sendBatches uses -1 to specify no limit.
+	batchLimit := int32(req.Limit)
+	if batchLimit == 0 {
+		batchLimit = -1
+	}
+
+	return sendBatches(ctx, it, queryServer, batchLimit)
 }
 
 // QuerySample the ingesters for series from logs matching a set of matchers.

pkg/ingester/instance.go

@@ -716,38 +716,23 @@ type QuerierQueryServer interface {
 	Send(res *logproto.QueryResponse) error
 }
 
-func sendBatches(ctx context.Context, i iter.EntryIterator, queryServer QuerierQueryServer, limit uint32) error {
+func sendBatches(ctx context.Context, i iter.EntryIterator, queryServer QuerierQueryServer, limit int32) error {
 	stats := stats.FromContext(ctx)
-	if limit == 0 {
-		// send all batches.
-		for !isDone(ctx) {
-			batch, size, err := iter.ReadBatch(i, queryBatchSize)
-			if err != nil {
-				return err
-			}
-			if len(batch.Streams) == 0 {
-				return nil
-			}
-			stats.AddIngesterBatch(int64(size))
-			batch.Stats = stats.Ingester()
 
-			if err := queryServer.Send(batch); err != nil {
-				return err
-			}
-
-			stats.Reset()
-
-		}
-		return nil
-	}
 	// send until the limit is reached.
-	sent := uint32(0)
-	for sent < limit && !isDone(queryServer.Context()) {
-		batch, batchSize, err := iter.ReadBatch(i, math.MinUint32(queryBatchSize, limit-sent))
+	for limit != 0 && !isDone(ctx) {
+		fetchSize := uint32(queryBatchSize)
+		if limit > 0 {
+			fetchSize = math.MinUint32(queryBatchSize, uint32(limit))
+		}
+		batch, batchSize, err := iter.ReadBatch(i, fetchSize)
 		if err != nil {
 			return err
 		}
-		sent += batchSize
+
+		if limit > 0 {
+			limit -= int32(batchSize)
+		}
 
 		if len(batch.Streams) == 0 {
 			return nil

pkg/ingester/instance_test.go

@@ -513,7 +513,7 @@ func Test_Iterator(t *testing.T) {
 					return nil
 				},
 			),
-			uint32(2)),
+			int32(2)),
 	)
 	require.Equal(t, 2, len(res.Streams))
 	// each entry translated into a unique stream