Merge pull request #8 from lorenzoranucci/refactoring

Delegate mapping between topic and aggregateId to event dispatcher adapter

.devenv/tor-bare-metal.yaml

@@ -3,16 +3,20 @@ dbPort: 3306
 dbUser: root
 dbPassword: root
 dbOutboxTableRef: my_schema.my_outbox_table
-dbHeadersColumnsNames:
-  - uuid
-topicsToPairWithAggregateTypeRegex:
-  - order
-  - invoice
-aggregateTypeRegexToPairWithTopics:
-  - "(?i)^order$"
-  - "(?i)^invoice$"
 
 kafkaBrokers: localhost:9093
+kafkaTopics:
+  - name: "order"
+    numPartitions: 1
+    replicationFactor: 1
+    aggregateTypeRegexp: "(?i)^order$"
+  - name: "invoice"
+    numPartitions: 1
+    replicationFactor: 1
+    aggregateTypeRegexp: "(?i)^invoice"
+kafkaHeaderMappings:
+  - columnName: "uuid"
+    headerName: "uuid"
 
 redisHost: localhost
 redisPort: 6379

.devenv/tor-docker.yaml

@@ -3,16 +3,20 @@ dbPort: 3306
 dbUser: root
 dbPassword: root
 dbOutboxTableRef: my_schema.my_outbox_table
-dbHeadersColumnsNames:
-  - uuid
-topicsToPairWithAggregateTypeRegex:
-  - order
-  - invoice
-aggregateTypeRegexToPairWithTopics:
-  - "(?i)^order$"
-  - "(?i)^invoice$"
 
 kafkaBrokers: kafka:9092
+kafkaTopics:
+  - name: "order"
+    numPartitions: 1
+    replicationFactor: 1
+    aggregateTypeRegexp: "(?i)^order$"
+  - name: "invoice"
+    numPartitions: 1
+    replicationFactor: 1
+    aggregateTypeRegexp: "(?i)^invoice"
+kafkaHeaderMappings:
+  - columnName: "uuid"
+    headerName: "uuid"
 
 redisHost: redis
 redisPort: 6379

adapters/kafka/event_dispatcher.go

@@ -1,36 +1,126 @@
 package kafka
 
-import "github.com/Shopify/sarama"
+import (
+	"fmt"
+	"regexp"
 
-func NewEventDispatcher(producer *Producer) *EventDispatcher {
-	return &EventDispatcher{producer: producer}
+	"github.com/Shopify/sarama"
+	"github.com/lorenzoranucci/tor/router/pkg/run"
+)
+
+func NewEventDispatcher(
+	syncProducer sarama.SyncProducer,
+	admin sarama.ClusterAdmin,
+	topics []Topic,
+	headerMappings []HeaderMapping,
+) (*EventDispatcher, error) {
+	err := createTopics(topics, admin)
+	if err != nil {
+		return nil, err
+	}
+
+	return &EventDispatcher{
+		syncProducer:   syncProducer,
+		admin:          admin,
+		topics:         topics,
+		headerMappings: headerMappings,
+	}, nil
 }
 
 type EventDispatcher struct {
-	producer *Producer
+	syncProducer   sarama.SyncProducer
+	admin          sarama.ClusterAdmin
+	topics         []Topic
+	headerMappings []HeaderMapping
+}
+
+type Topic struct {
+	Name          string
+	TopicDetail   *sarama.TopicDetail
+	AggregateType *regexp.Regexp
+}
+
+type HeaderMapping struct {
+	ColumnName string
+	HeaderName string
 }
 
-func (k *EventDispatcher) Dispatch(
-	topic string,
-	routingKey string,
-	event []byte,
-	headers []struct {
-		Key   []byte
-		Value []byte
-	},
-) error {
-	return k.producer.Dispatch(topic, routingKey, event, mapHeaders(headers))
+func (k *EventDispatcher) Dispatch(event run.OutboxEvent) error {
+	for _, topic := range k.topics {
+		if !topic.AggregateType.MatchString(string(event.AggregateType)) {
+			continue
+		}
+
+		headers, err := k.mapHeaders(event.Columns)
+		if err != nil {
+			return err
+		}
+
+		_, _, err = k.syncProducer.SendMessage(
+			&sarama.ProducerMessage{
+				Key:     sarama.ByteEncoder(event.AggregateID),
+				Topic:   topic.Name,
+				Value:   sarama.ByteEncoder(event.Payload),
+				Headers: headers,
+			},
+		)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
 }
 
-func mapHeaders(h []struct {
-	Key   []byte
-	Value []byte
-}) []sarama.RecordHeader {
-	r := make([]sarama.RecordHeader, 0, len(h))
+func createTopics(topics []Topic, admin sarama.ClusterAdmin) error {
+	topicNames := make([]string, 0, len(topics))
+	for _, topic := range topics {
+		topicNames = append(topicNames, topic.Name)
+	}
+
+	topicMetadata, err := admin.DescribeTopics(topicNames)
+	if err != nil {
+		return err
+	}
+
+	for _, m := range topicMetadata {
+		if m.Err != sarama.ErrUnknownTopicOrPartition {
+			continue
+		}
+
+		for _, topic := range topics {
+			if topic.Name != m.Name {
+				continue
+			}
+
+			err := admin.CreateTopic(topic.Name, topic.TopicDetail, false)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (k *EventDispatcher) mapHeaders(columns []run.Column) ([]sarama.RecordHeader, error) {
+	r := make([]sarama.RecordHeader, 0, len(columns))
+
+outerLoop:
+	for _, h := range k.headerMappings {
+		for _, c := range columns {
+			if h.ColumnName == string(c.Name) {
+				r = append(r, sarama.RecordHeader{
+					Key:   []byte(h.HeaderName),
+					Value: c.Value,
+				})
+
+				continue outerLoop
+			}
+		}
 
-	for _, v := range h {
-		r = append(r, v)
+		return nil, fmt.Errorf("column not found for header. Column: %s, Header: %s", h.ColumnName, h.HeaderName)
 	}
 
-	return r
+	return r, nil
 }

adapters/redis/state_handler.go

@@ -36,7 +36,7 @@ func (r *StateHandler) GetLastPosition() (mysql.Position, error) {
 	return mysql.Position{
 		Name: p.Name,
 		Pos:  p.Pos,
-	}, err
+	}, nil
 }
 
 func (r *StateHandler) SetLastPosition(p mysql.Position) error {