seaweedfs/weed/mq/pub_balancer/lookup.go
chrislu 35869b5c80 subscriber can be notified of the assignment change when topic is just configured
Next: Subscriber needs to read by the timestamp offset.
2024-01-03 13:30:30 -08:00

55 lines
1.8 KiB
Go

package pub_balancer
import (
"errors"
"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
)
var (
ErrNoBroker = errors.New("no broker")
)
func (balancer *Balancer) LookupOrAllocateTopicPartitions(topic *mq_pb.Topic, publish bool, partitionCount int32) (assignments []*mq_pb.BrokerPartitionAssignment, err error) {
if partitionCount == 0 {
partitionCount = 6
}
// find existing topic partition assignments
for brokerStatsItem := range balancer.Brokers.IterBuffered() {
broker, brokerStats := brokerStatsItem.Key, brokerStatsItem.Val
for topicPartitionStatsItem := range brokerStats.TopicPartitionStats.IterBuffered() {
topicPartitionStat := topicPartitionStatsItem.Val
if topicPartitionStat.TopicPartition.Namespace == topic.Namespace &&
topicPartitionStat.TopicPartition.Name == topic.Name {
assignment := &mq_pb.BrokerPartitionAssignment{
Partition: &mq_pb.Partition{
RingSize: MaxPartitionCount,
RangeStart: topicPartitionStat.RangeStart,
RangeStop: topicPartitionStat.RangeStop,
},
}
// TODO fix follower setting
assignment.LeaderBroker = broker
assignments = append(assignments, assignment)
}
}
}
if len(assignments) > 0 || !(publish && len(assignments) !=int(partitionCount) && partitionCount > 0) {
// glog.V(0).Infof("existing topic partitions %d: %v", len(assignments), assignments)
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)
if balancer.Brokers.IsEmpty() {
return nil, ErrNoBroker
}
assignments = allocateTopicPartitions(balancer.Brokers, partitionCount)
balancer.OnPartitionChange(topic, assignments)
return
}