56 lines
984 B
Go
56 lines
984 B
Go
package broker
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import (
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"encoding/json"
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"sync"
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)
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// Event is a JSON-serialisable message pushed to WebSocket clients.
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type Event struct {
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Type string `json:"type"`
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AgentID string `json:"agent_id,omitempty"`
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Payload any `json:"payload"`
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}
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type subscriber chan []byte
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// Broker fan-outs events to all registered WebSocket subscribers.
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type Broker struct {
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mu sync.RWMutex
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subs map[subscriber]struct{}
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}
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func New() *Broker {
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return &Broker{subs: make(map[subscriber]struct{})}
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}
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func (b *Broker) Subscribe() subscriber {
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ch := make(subscriber, 32)
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b.mu.Lock()
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b.subs[ch] = struct{}{}
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b.mu.Unlock()
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return ch
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}
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func (b *Broker) Unsubscribe(ch subscriber) {
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b.mu.Lock()
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delete(b.subs, ch)
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b.mu.Unlock()
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close(ch)
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}
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func (b *Broker) Publish(evt Event) {
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data, err := json.Marshal(evt)
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if err != nil {
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return
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}
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b.mu.RLock()
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defer b.mu.RUnlock()
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for ch := range b.subs {
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select {
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case ch <- data:
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default: // drop if subscriber is slow
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}
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}
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}
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