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|
package old
import (
"context"
"errors"
"sync/atomic"
"github.com/go-redis/redis/v8"
)
// Redis based broadcast Router.
type Redis struct {
client redis.UniversalClient
psClient redis.UniversalClient
router *Router
messages chan *Message
listen, leave chan subscriber
stop chan interface{}
stopped int32
}
// creates new redis broker
func redisBroker(cfg *RedisConfig) (*Redis, error) {
client := cfg.redisClient()
if _, err := client.Ping(context.Background()).Result(); err != nil {
return nil, err
}
psClient := cfg.redisClient()
if _, err := psClient.Ping(context.Background()).Result(); err != nil {
return nil, err
}
return &Redis{
client: client,
psClient: psClient,
router: NewRouter(),
messages: make(chan *Message),
listen: make(chan subscriber),
leave: make(chan subscriber),
stop: make(chan interface{}),
stopped: 0,
}, nil
}
// Serve serves broker.
func (r *Redis) Serve() error {
pubsub := r.psClient.Subscribe(context.Background())
channel := pubsub.Channel()
for {
select {
case ctx := <-r.listen:
ctx.done <- r.handleJoin(ctx, pubsub)
case ctx := <-r.leave:
ctx.done <- r.handleLeave(ctx, pubsub)
case msg := <-channel:
r.router.Dispatch(&Message{
Topic: msg.Channel,
Payload: []byte(msg.Payload),
})
case <-r.stop:
return nil
}
}
}
func (r *Redis) handleJoin(sub subscriber, pubsub *redis.PubSub) error {
if sub.pattern != "" {
newPatterns, err := r.router.SubscribePattern(sub.upstream, sub.pattern)
if err != nil || len(newPatterns) == 0 {
return err
}
return pubsub.PSubscribe(context.Background(), newPatterns...)
}
newTopics := r.router.Subscribe(sub.upstream, sub.topics...)
if len(newTopics) == 0 {
return nil
}
return pubsub.Subscribe(context.Background(), newTopics...)
}
func (r *Redis) handleLeave(sub subscriber, pubsub *redis.PubSub) error {
if sub.pattern != "" {
dropPatterns := r.router.UnsubscribePattern(sub.upstream, sub.pattern)
if len(dropPatterns) == 0 {
return nil
}
return pubsub.PUnsubscribe(context.Background(), dropPatterns...)
}
dropTopics := r.router.Unsubscribe(sub.upstream, sub.topics...)
if len(dropTopics) == 0 {
return nil
}
return pubsub.Unsubscribe(context.Background(), dropTopics...)
}
// Stop closes the consumption and disconnects broker.
func (r *Redis) Stop() {
if atomic.CompareAndSwapInt32(&r.stopped, 0, 1) {
close(r.stop)
}
}
// Subscribe broker to one or multiple channels.
func (r *Redis) Subscribe(upstream chan *Message, topics ...string) error {
if atomic.LoadInt32(&r.stopped) == 1 {
return errors.New("broker has been stopped")
}
ctx := subscriber{upstream: upstream, topics: topics, done: make(chan error)}
r.listen <- ctx
return <-ctx.done
}
// SubscribePattern broker to pattern.
func (r *Redis) SubscribePattern(upstream chan *Message, pattern string) error {
if atomic.LoadInt32(&r.stopped) == 1 {
return errors.New("broker has been stopped")
}
ctx := subscriber{upstream: upstream, pattern: pattern, done: make(chan error)}
r.listen <- ctx
return <-ctx.done
}
// Unsubscribe broker from one or multiple channels.
func (r *Redis) Unsubscribe(upstream chan *Message, topics ...string) error {
if atomic.LoadInt32(&r.stopped) == 1 {
return errors.New("broker has been stopped")
}
ctx := subscriber{upstream: upstream, topics: topics, done: make(chan error)}
r.leave <- ctx
return <-ctx.done
}
// UnsubscribePattern broker from pattern.
func (r *Redis) UnsubscribePattern(upstream chan *Message, pattern string) error {
if atomic.LoadInt32(&r.stopped) == 1 {
return errors.New("broker has been stopped")
}
ctx := subscriber{upstream: upstream, pattern: pattern, done: make(chan error)}
r.leave <- ctx
return <-ctx.done
}
// Publish one or multiple Channel.
func (r *Redis) Publish(messages ...*Message) error {
if atomic.LoadInt32(&r.stopped) == 1 {
return errors.New("broker has been stopped")
}
for _, msg := range messages {
if err := r.client.Publish(context.Background(), msg.Topic, []byte(msg.Payload)).Err(); err != nil {
return err
}
}
return nil
}
|
