105 lines
2.3 KiB
Go
105 lines
2.3 KiB
Go
package server
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import (
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"encoding/json"
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"strings"
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"sync"
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)
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// Defines all of the possible output events for a server.
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// noinspection GoNameStartsWithPackageName
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const (
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DaemonMessageEvent = "daemon message"
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InstallOutputEvent = "install output"
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ConsoleOutputEvent = "console output"
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StatusEvent = "status"
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StatsEvent = "stats"
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BackupCompletedEvent = "backup completed"
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)
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type Event struct {
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Data string
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Topic string
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}
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type EventBus struct {
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subscribers map[string][]chan Event
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mu sync.Mutex
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}
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// Returns the server's emitter instance.
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func (s *Server) Events() *EventBus {
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if s.emitter == nil {
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s.emitter = &EventBus{
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subscribers: map[string][]chan Event{},
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}
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}
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return s.emitter
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}
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// Publish data to a given topic.
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func (e *EventBus) Publish(topic string, data string) {
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e.mu.Lock()
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defer e.mu.Unlock()
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t := topic
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// Some of our topics for the socket support passing a more specific namespace,
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// such as "backup completed:1234" to indicate which specific backup was completed.
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//
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// In these cases, we still need to the send the event using the standard listener
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// name of "backup completed".
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if strings.Contains(topic, ":") {
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parts := strings.SplitN(topic, ":", 2)
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if len(parts) == 2 {
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t = parts[0]
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}
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}
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if ch, ok := e.subscribers[t]; ok {
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go func(data Event, cs []chan Event) {
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for _, channel := range cs {
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channel <- data
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}
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}(Event{Data: data, Topic: topic}, ch)
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}
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}
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func (e *EventBus) PublishJson(topic string, data interface{}) error {
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b, err := json.Marshal(data)
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if err != nil {
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return err
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}
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e.Publish(topic, string(b))
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return nil
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}
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// Subscribe to an emitter topic using a channel.
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func (e *EventBus) Subscribe(topic string, ch chan Event) {
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e.mu.Lock()
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defer e.mu.Unlock()
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if p, ok := e.subscribers[topic]; ok {
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e.subscribers[topic] = append(p, ch)
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} else {
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e.subscribers[topic] = append([]chan Event{}, ch)
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}
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}
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// Unsubscribe a channel from a topic.
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func (e *EventBus) Unsubscribe(topic string, ch chan Event) {
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e.mu.Lock()
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defer e.mu.Unlock()
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if _, ok := e.subscribers[topic]; ok {
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for i := range e.subscribers[topic] {
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if ch == e.subscribers[topic][i] {
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e.subscribers[topic] = append(e.subscribers[topic][:i], e.subscribers[topic][i+1:]...)
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}
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}
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}
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}
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