68 lines
1.2 KiB
Go
68 lines
1.2 KiB
Go
package events
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type Bus struct {
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topics map[string]*topic
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}
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func New() *Bus {
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return &Bus{topics: make(map[string]*topic)}
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}
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func (d *Bus) On(event string, receiver interface{}) error {
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// TODO: make thread safe
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t, hasTopic := d.topics[event]
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if !hasTopic {
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t = &topic{}
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d.topics[event] = t
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}
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sub, err := newSubscriptionFromFunc(receiver)
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if err != nil {
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return err
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}
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t.addSubscriber(sub)
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return nil
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}
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func (d *Bus) Fire(event string, args ...interface{}) {
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// TODO: make thead safe
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topic, hasTopic := d.topics[event]
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if !hasTopic {
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return
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}
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preparedArgs := prepareArgs(args)
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for sub := topic.head; sub != nil; sub = sub.next {
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sub.handler.invoke(preparedArgs)
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}
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}
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type topic struct {
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head *subscription
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tail *subscription
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}
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func (t *topic) addSubscriber(sub *subscription) {
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if t.head == nil {
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t.head = sub
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}
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if t.tail != nil {
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t.tail.next = sub
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}
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t.tail = sub
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}
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type subscription struct {
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handler receiptHandler
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next *subscription
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}
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func newSubscriptionFromFunc(fn interface{}) (*subscription, error) {
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handler, err := newReceiptHandler(fn)
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if err != nil {
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return nil, err
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}
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return &subscription{handler: handler, next: nil}, nil
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} |