Batcher now returns error if bad config is provided

batchconsumer/batcher/message_batcher.go

@@ -76,8 +76,18 @@ type batcher struct {
 // - flushInterval - how often accumulated messages should be flushed (default 1 second).
 // - flushCount - number of messages that trigger a flush (default 10).
 // - flushSize - size of batch that triggers a flush (default 1024 * 1024 = 1 mb)
-func New(sync Sync, flushInterval time.Duration, flushCount int, flushSize int) Batcher {
+func New(sync Sync, flushInterval time.Duration, flushCount int, flushSize int) (Batcher, error) {
-	msgChan := make(chan msgPack, 100)
+	if flushSize == 0 {
+		return nil, fmt.Errorf("flush size must be non-zero")
+	}
+	if flushCount == 0 {
+		return nil, fmt.Errorf("flush count must be non-zero")
+	}
+	if flushInterval == 0 {
+		return nil, fmt.Errorf("flush interval must be non-zero")
+	}
+
+	msgChan := make(chan msgPack)
 	flushChan := make(chan struct{})
 
 	b := &batcher{
@@ -91,7 +101,7 @@ func New(sync Sync, flushInterval time.Duration, flushCount int, flushSize int)
 
 	go b.startBatcher(msgChan, flushChan)
 
-	return b
+	return b, nil
 }
 
 func (b *batcher) SmallestSequencePair() SequencePair {

batchconsumer/batcher/message_batcher_test.go

@@ -40,11 +40,11 @@ func (m *MockSync) waitForFlush(timeout time.Duration) error {
 var mockSequence = SequencePair{big.NewInt(99999), 12345}
 
 func TestBatchingByCount(t *testing.T) {
-	var err error
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Hour, 2, 1024*1024)
+	batcher, err := New(sync, time.Hour, 2, 1024*1024)
+	assert.NoError(err)
 
 	t.Log("Batcher respect count limit")
 	assert.NoError(batcher.AddMessage([]byte("hihi"), mockSequence))
@@ -65,11 +65,11 @@ func TestBatchingByCount(t *testing.T) {
 }
 
 func TestBatchingByTime(t *testing.T) {
-	var err error
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Millisecond, 2000000, 1024*1024)
+	batcher, err := New(sync, time.Millisecond, 2000000, 1024*1024)
+	assert.NoError(err)
 
 	t.Log("Batcher sends partial batches when time expires")
 	assert.NoError(batcher.AddMessage([]byte("hihi"), mockSequence))
@@ -99,11 +99,11 @@ func TestBatchingByTime(t *testing.T) {
 }
 
 func TestBatchingBySize(t *testing.T) {
-	var err error
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Hour, 2000000, 8)
+	batcher, err := New(sync, time.Hour, 2000000, 8)
+	assert.NoError(err)
 
 	t.Log("Large messages are sent immediately")
 	assert.NoError(batcher.AddMessage([]byte("hellohello"), mockSequence))
@@ -145,11 +145,11 @@ func TestBatchingBySize(t *testing.T) {
 }
 
 func TestFlushing(t *testing.T) {
-	var err error
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Hour, 2000000, 1024*1024)
+	batcher, err := New(sync, time.Hour, 2000000, 1024*1024)
+	assert.NoError(err)
 
 	t.Log("Calling flush sends pending messages")
 	assert.NoError(batcher.AddMessage([]byte("hihi"), mockSequence))
@@ -168,11 +168,11 @@ func TestFlushing(t *testing.T) {
 }
 
 func TestSendingEmpty(t *testing.T) {
-	var err error
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Second, 10, 1024*1024)
+	batcher, err := New(sync, time.Second, 10, 1024*1024)
+	assert.NoError(err)
 
 	t.Log("An error is returned when an empty message is sent")
 	err = batcher.AddMessage([]byte{}, mockSequence)
@@ -184,7 +184,10 @@ func TestUpdatingSequence(t *testing.T) {
 	assert := assert.New(t)
 
 	sync := NewMockSync()
-	batcher := New(sync, time.Second, 10, 1024*1024).(*batcher)
+	b, err := New(sync, time.Second, 10, 1024*1024)
+	assert.NoError(err)
+
+	batcher := b.(*batcher)
 
 	t.Log("Initally, smallestSeq is undefined")
 	assert.Nil(batcher.SmallestSequencePair().Sequence)

batchconsumer/writer.go

@@ -118,7 +118,12 @@ func (b *batchedWriter) createBatcher(tag string) batcher.Batcher {
 		tag:    tag,
 		writer: b,
 	}
-	return batcher.New(sync, b.config.BatchInterval, b.config.BatchCount, b.config.BatchSize)
+	batch, err := batcher.New(sync, b.config.BatchInterval, b.config.BatchCount, b.config.BatchSize)
+	if err != nil {
+		b.log.ErrorD("create-batcher", kv.M{"msg": err.Error(), "tag": tag})
+	}
+
+	return batch
 }
 
 func (b *batchedWriter) splitMessageIfNecessary(record []byte) ([][]byte, error) {