Opentracing support

vendor/github.com/Shopify/sarama/sync_producer.go

@@ -0,0 +1,164 @@
+package sarama
+
+import "sync"
+
+// SyncProducer publishes Kafka messages, blocking until they have been acknowledged. It routes messages to the correct
+// broker, refreshing metadata as appropriate, and parses responses for errors. You must call Close() on a producer
+// to avoid leaks, it may not be garbage-collected automatically when it passes out of scope.
+//
+// The SyncProducer comes with two caveats: it will generally be less efficient than the AsyncProducer, and the actual
+// durability guarantee provided when a message is acknowledged depend on the configured value of `Producer.RequiredAcks`.
+// There are configurations where a message acknowledged by the SyncProducer can still sometimes be lost.
+//
+// For implementation reasons, the SyncProducer requires `Producer.Return.Errors` and `Producer.Return.Successes` to
+// be set to true in its configuration.
+type SyncProducer interface {
+
+	// SendMessage produces a given message, and returns only when it either has
+	// succeeded or failed to produce. It will return the partition and the offset
+	// of the produced message, or an error if the message failed to produce.
+	SendMessage(msg *ProducerMessage) (partition int32, offset int64, err error)
+
+	// SendMessages produces a given set of messages, and returns only when all
+	// messages in the set have either succeeded or failed. Note that messages
+	// can succeed and fail individually; if some succeed and some fail,
+	// SendMessages will return an error.
+	SendMessages(msgs []*ProducerMessage) error
+
+	// Close shuts down the producer and waits for any buffered messages to be
+	// flushed. You must call this function before a producer object passes out of
+	// scope, as it may otherwise leak memory. You must call this before calling
+	// Close on the underlying client.
+	Close() error
+}
+
+type syncProducer struct {
+	producer *asyncProducer
+	wg       sync.WaitGroup
+}
+
+// NewSyncProducer creates a new SyncProducer using the given broker addresses and configuration.
+func NewSyncProducer(addrs []string, config *Config) (SyncProducer, error) {
+	if config == nil {
+		config = NewConfig()
+		config.Producer.Return.Successes = true
+	}
+
+	if err := verifyProducerConfig(config); err != nil {
+		return nil, err
+	}
+
+	p, err := NewAsyncProducer(addrs, config)
+	if err != nil {
+		return nil, err
+	}
+	return newSyncProducerFromAsyncProducer(p.(*asyncProducer)), nil
+}
+
+// NewSyncProducerFromClient creates a new SyncProducer using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this producer.
+func NewSyncProducerFromClient(client Client) (SyncProducer, error) {
+	if err := verifyProducerConfig(client.Config()); err != nil {
+		return nil, err
+	}
+
+	p, err := NewAsyncProducerFromClient(client)
+	if err != nil {
+		return nil, err
+	}
+	return newSyncProducerFromAsyncProducer(p.(*asyncProducer)), nil
+}
+
+func newSyncProducerFromAsyncProducer(p *asyncProducer) *syncProducer {
+	sp := &syncProducer{producer: p}
+
+	sp.wg.Add(2)
+	go withRecover(sp.handleSuccesses)
+	go withRecover(sp.handleErrors)
+
+	return sp
+}
+
+func verifyProducerConfig(config *Config) error {
+	if !config.Producer.Return.Errors {
+		return ConfigurationError("Producer.Return.Errors must be true to be used in a SyncProducer")
+	}
+	if !config.Producer.Return.Successes {
+		return ConfigurationError("Producer.Return.Successes must be true to be used in a SyncProducer")
+	}
+	return nil
+}
+
+func (sp *syncProducer) SendMessage(msg *ProducerMessage) (partition int32, offset int64, err error) {
+	oldMetadata := msg.Metadata
+	defer func() {
+		msg.Metadata = oldMetadata
+	}()
+
+	expectation := make(chan *ProducerError, 1)
+	msg.Metadata = expectation
+	sp.producer.Input() <- msg
+
+	if err := <-expectation; err != nil {
+		return -1, -1, err.Err
+	}
+
+	return msg.Partition, msg.Offset, nil
+}
+
+func (sp *syncProducer) SendMessages(msgs []*ProducerMessage) error {
+	savedMetadata := make([]interface{}, len(msgs))
+	for i := range msgs {
+		savedMetadata[i] = msgs[i].Metadata
+	}
+	defer func() {
+		for i := range msgs {
+			msgs[i].Metadata = savedMetadata[i]
+		}
+	}()
+
+	expectations := make(chan chan *ProducerError, len(msgs))
+	go func() {
+		for _, msg := range msgs {
+			expectation := make(chan *ProducerError, 1)
+			msg.Metadata = expectation
+			sp.producer.Input() <- msg
+			expectations <- expectation
+		}
+		close(expectations)
+	}()
+
+	var errors ProducerErrors
+	for expectation := range expectations {
+		if err := <-expectation; err != nil {
+			errors = append(errors, err)
+		}
+	}
+
+	if len(errors) > 0 {
+		return errors
+	}
+	return nil
+}
+
+func (sp *syncProducer) handleSuccesses() {
+	defer sp.wg.Done()
+	for msg := range sp.producer.Successes() {
+		expectation := msg.Metadata.(chan *ProducerError)
+		expectation <- nil
+	}
+}
+
+func (sp *syncProducer) handleErrors() {
+	defer sp.wg.Done()
+	for err := range sp.producer.Errors() {
+		expectation := err.Msg.Metadata.(chan *ProducerError)
+		expectation <- err
+	}
+}
+
+func (sp *syncProducer) Close() error {
+	sp.producer.AsyncClose()
+	sp.wg.Wait()
+	return nil
+}