1 files changed, 43 insertions, 0 deletions
diff --git a/weed/mq/balancer/lookup.go b/weed/mq/balancer/lookup.go
new file mode 100644
index 000000000..55ed3e95d
--- /dev/null
+++ b/weed/mq/balancer/lookup.go
@@ -0,0 +1,43 @@
+package balancer
+
+import (
+	"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
+)
+
+func (b *Balancer) LookupOrAllocateTopicPartitions(topic *mq_pb.Topic, publish bool) (assignments []*mq_pb.BrokerPartitionAssignment, err error) {
+	// find existing topic partition assignments
+	for brokerStatsItem := range b.Brokers.IterBuffered() {
+		broker, brokerStats := brokerStatsItem.Key, brokerStatsItem.Val
+		for topicPartitionStatsItem := range brokerStats.Stats.IterBuffered() {
+			topicPartitionStat := topicPartitionStatsItem.Val
+			if topicPartitionStat.TopicPartition.Namespace == topic.Namespace &&
+				topicPartitionStat.TopicPartition.Topic == topic.Name {
+				assignment := &mq_pb.BrokerPartitionAssignment{
+					Partition: &mq_pb.Partition{
+						RingSize:   MaxPartitionCount,
+						RangeStart: topicPartitionStat.RangeStart,
+						RangeStop:  topicPartitionStat.RangeStop,
+					},
+				}
+				if topicPartitionStat.IsLeader {
+					assignment.LeaderBroker = broker
+				} else {
+					assignment.FollowerBrokers = append(assignment.FollowerBrokers, broker)
+				}
+				assignments = append(assignments, assignment)
+			}
+		}
+	}
+	if len(assignments) > 0 {
+		return assignments, nil
+	}
+
+	// find the topic partitions on the filer
+	// if the topic is not found
+	//   if the request is_for_publish
+	//     create the topic
+	//   if the request is_for_subscribe
+	//     return error not found
+	// t := topic.FromPbTopic(request.Topic)
+	return allocateTopicPartitions(b.Brokers, 6), nil
+}