90 lines
2.2 KiB
Go
90 lines
2.2 KiB
Go
package adapters
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import (
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"context"
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"sync"
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"time"
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"atri.dad/lib"
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"atri.dad/lib/pubsub"
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)
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type LocalPubSub struct {
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subscribers map[string][]chan pubsub.Message
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lock sync.RWMutex
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}
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type LocalPubSubMessage struct {
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messages <-chan pubsub.Message
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}
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func (ps *LocalPubSub) SubscribeToChannel(channel string) (pubsub.PubSubMessage, error) {
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ps.lock.Lock()
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defer ps.lock.Unlock()
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if ps.subscribers == nil {
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ps.subscribers = make(map[string][]chan pubsub.Message)
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}
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ch := make(chan pubsub.Message, 100)
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ps.subscribers[channel] = append(ps.subscribers[channel], ch)
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lib.LogInfo.Printf("[PUBSUB/LOCAL] Subscribed to channel %s\n", channel)
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return &LocalPubSubMessage{messages: ch}, nil
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}
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func (ps *LocalPubSub) PublishToChannel(channel string, message string) error {
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subscribers, ok := ps.subscribers[channel]
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if !ok {
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lib.LogWarning.Printf("\n[PUBSUB/LOCAL] No subscribers for channel %s\n", channel)
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return nil
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}
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ps.lock.Lock()
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defer ps.lock.Unlock()
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lib.LogInfo.Printf("\n[PUBSUB/LOCAL] Publishing message to channel %s: %s\n", channel, message)
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for _, ch := range subscribers {
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ch <- pubsub.Message{Payload: message}
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}
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return nil
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}
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func (ps *LocalPubSub) UnsubscribeFromChannel(channel string, ch <-chan pubsub.Message) {
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ps.lock.Lock()
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defer ps.lock.Unlock()
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subscribers := ps.subscribers[channel]
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for i, subscriber := range subscribers {
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if subscriber == ch {
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// Remove the subscriber from the slice
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subscribers = append(subscribers[:i], subscribers[i+1:]...)
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break
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}
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}
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if len(subscribers) == 0 {
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delete(ps.subscribers, channel)
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} else {
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ps.subscribers[channel] = subscribers
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}
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}
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func (m *LocalPubSubMessage) ReceiveMessage(ctx context.Context) (*pubsub.Message, error) {
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for {
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select {
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case <-ctx.Done():
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// The client has disconnected. Stop trying to send messages.
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return nil, ctx.Err()
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case msg := <-m.messages:
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// A message has been received. Send it to the client.
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lib.LogInfo.Printf("\n[PUBSUB/LOCAL] Received message: %s\n", msg.Payload)
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return &msg, nil
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case <-time.After(30 * time.Second):
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// No message has been received for 30 seconds. Send a keep-alive message.
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return &pubsub.Message{Payload: "keep-alive"}, nil
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}
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}
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}
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