improve Put error response (#15)

Author: gammazero

dsqueue.go

@@ -101,10 +101,9 @@ func (q *DSQueue) Put(item []byte) (err error) {
 	}
 	defer func() {
 		if r := recover(); r != nil {
-			err = fmt.Errorf("failed to enqueue item: %s", r)
+			err = fmt.Errorf("%s queue closed", q.name)
 		}
 	}()
-
 	q.enqueue <- item
 	return
 }
@@ -130,6 +129,9 @@ type getResponse struct {
 // should not be used concurrently as items will be returned by one or the
 // other indeterminately.
 func (q *DSQueue) GetN(n int) ([][]byte, error) {
+	if n == 0 {
+		return nil, nil
+	}
 	rsp := make(chan getResponse)
 	q.getn <- getRequest{
 		n:   n,
@@ -347,9 +349,6 @@ func (q *DSQueue) worker(ctx context.Context, bufferSize, dedupCacheSize int, id
 			idle = true
 			batchTimer.Reset(idleWriteTime)
 
-		case <-ctx.Done():
-			return
-
 		case rsp := <-q.clear:
 			var rmMemCount int
 			if item != nil {

dsqueue_test.go

@@ -94,6 +94,11 @@ func TestBasicOperation(t *testing.T) {
 	if err == nil {
 		t.Fatal("expected error calling Enqueue after Close")
 	}
+
+	_, err = queue.GetN(5)
+	if err == nil {
+		t.Fatal("expected error calling GetN after Close")
+	}
 }
 
 func TestGetN(t *testing.T) {
@@ -141,7 +146,7 @@ func TestMangledData(t *testing.T) {
 	// put bad data in the queue
 	qds := namespace.Wrap(ds, datastore.NewKey("/dsq-"+dsqName))
 	item := "borked"
-	queueKey := datastore.NewKey(fmt.Sprintf("%s", item))
+	queueKey := datastore.NewKey(item)
 	err := qds.Put(context.Background(), queueKey, []byte(item))
 	if err != nil {
 		t.Fatal(err)