milvus/internal/util/mqclient/consumer.go

75 lines
2.1 KiB
Go

package mqclient
type SubscriptionInitialPosition int
const (
// Latest position which means the start consuming position will be the last message
SubscriptionPositionLatest SubscriptionInitialPosition = iota
// Earliest position which means the start consuming position will be the first message
SubscriptionPositionEarliest
)
type SubscriptionType int
const (
// Exclusive there can be only 1 consumer on the same topic with the same subscription name
Exclusive SubscriptionType = iota
// Shared subscription mode, multiple consumer will be able to use the same subscription name
// and the messages will be dispatched according to
// a round-robin rotation between the connected consumers
Shared
// Failover subscription mode, multiple consumer will be able to use the same subscription name
// but only 1 consumer will receive the messages.
// If that consumer disconnects, one of the other connected consumers will start receiving messages.
Failover
// KeyShared subscription mode, multiple consumer will be able to use the same
// subscription and all messages with the same key will be dispatched to only one consumer
KeyShared
)
type UniqueID = int64
type ConsumerOptions struct {
// The topic that this consumer will subscribe on
Topic string
// The subscription name for this consumer
SubscriptionName string
// InitialPosition at which the cursor will be set when subscribe
// Default is `Latest`
SubscriptionInitialPosition
// Message for this consumer
// When a message is received, it will be pushed to this channel for consumption
MessageChannel chan ConsumerMessage
// Set receive channel size
BufSize int64
// Select the subscription type to be used when subscribing to the topic.
// Default is `Exclusive`
Type SubscriptionType
}
type Consumer interface {
// returns the subscription for the consumer
Subscription() string
// Message channel
Chan() <-chan ConsumerMessage
// Seek to the uniqueID position
Seek(MessageID) error //nolint:govet
// Make sure that msg is received. Only used in pulsar
Ack(ConsumerMessage)
// Close consumer
Close()
}