|
| 1 | +package eio |
| 2 | + |
| 3 | +import ( |
| 4 | + "go.uber.org/zap" |
| 5 | + "reflect" |
| 6 | + "sync" |
| 7 | +) |
| 8 | + |
| 9 | +var _ Emitter = (*emitter)(nil) |
| 10 | + |
| 11 | +const ( |
| 12 | + TopicOpen = "open" |
| 13 | + TopicClose = "close" |
| 14 | + TopicUpgrading = "upgrading" |
| 15 | + TopicConnect = "connect" |
| 16 | + TopicConnection = "connection" |
| 17 | + TopicDisconnect = "disconnect" |
| 18 | + TopicDisconnecting = "disconnecting" |
| 19 | + TopicHeartbeat = "heartbeat" |
| 20 | + TopicError = "error" |
| 21 | + TopicData = "data" |
| 22 | + TopicMessage = "message" |
| 23 | + TopicPacket = "packet" |
| 24 | + TopicDrain = "drain" |
| 25 | + TopicFlush = "flush" |
| 26 | +) |
| 27 | + |
| 28 | +type ( |
| 29 | + Event struct { |
| 30 | + Topic string |
| 31 | + Args []any |
| 32 | + } |
| 33 | + |
| 34 | + Listener func(event *Event) error |
| 35 | + |
| 36 | + Emitter interface { |
| 37 | + On(topic string, listeners ...Listener) |
| 38 | + Once(topic string, listeners ...Listener) |
| 39 | + OffListeners(topic string, listeners ...Listener) |
| 40 | + Off(topics ...string) |
| 41 | + Emit(topic string, args ...any) error |
| 42 | + Has(topic string) bool |
| 43 | + Listeners(topic string) []Listener |
| 44 | + } |
| 45 | + |
| 46 | + emitter struct { |
| 47 | + mu sync.RWMutex |
| 48 | + listeners map[string][]Listener |
| 49 | + log *zap.Logger |
| 50 | + } |
| 51 | +) |
| 52 | + |
| 53 | +func (e Event) Get(index uint, dflt ...any) (r any) { |
| 54 | + for _, n := range dflt { |
| 55 | + r = n |
| 56 | + break |
| 57 | + } |
| 58 | + if len(e.Args) > int(index) { |
| 59 | + r = e.Args[index] |
| 60 | + } |
| 61 | + return |
| 62 | +} |
| 63 | + |
| 64 | +func (e Event) Int(index uint, dflt ...int) (r int) { |
| 65 | + for _, n := range dflt { |
| 66 | + r = n |
| 67 | + break |
| 68 | + } |
| 69 | + if len(e.Args) > int(index) { |
| 70 | + if n, ok := e.Args[index].(int); ok { |
| 71 | + r = n |
| 72 | + } |
| 73 | + } |
| 74 | + return |
| 75 | +} |
| 76 | + |
| 77 | +func (e Event) String(index uint, dflt ...string) (r string) { |
| 78 | + for _, n := range dflt { |
| 79 | + r = n |
| 80 | + break |
| 81 | + } |
| 82 | + if len(e.Args) > int(index) { |
| 83 | + if c, ok := e.Args[index].(string); ok { |
| 84 | + r = c |
| 85 | + } |
| 86 | + } |
| 87 | + return |
| 88 | +} |
| 89 | + |
| 90 | +func (e Event) Err(index uint, dflt ...error) (r error) { |
| 91 | + for _, n := range dflt { |
| 92 | + r = n |
| 93 | + break |
| 94 | + } |
| 95 | + if len(e.Args) > int(index) { |
| 96 | + if c, ok := e.Args[index].(error); ok { |
| 97 | + r = c |
| 98 | + } |
| 99 | + } |
| 100 | + return |
| 101 | +} |
| 102 | + |
| 103 | +func once(emitter Emitter, topic string, listeners ...Listener) []Listener { |
| 104 | + data := make([]Listener, len(listeners)) |
| 105 | + |
| 106 | + for i, listener := range listeners { |
| 107 | + var fn Listener |
| 108 | + fn = func(event *Event) error { |
| 109 | + emitter.OffListeners(topic, fn) |
| 110 | + return listener(event) |
| 111 | + } |
| 112 | + data[i] = fn |
| 113 | + } |
| 114 | + return data |
| 115 | +} |
| 116 | + |
| 117 | +func NewEmitter(logger *zap.Logger) *emitter { |
| 118 | + return &emitter{ |
| 119 | + listeners: make(map[string][]Listener), |
| 120 | + log: logger, |
| 121 | + } |
| 122 | +} |
| 123 | + |
| 124 | +func (e *emitter) On(topic string, listeners ...Listener) { |
| 125 | + if len(listeners) == 0 { |
| 126 | + return |
| 127 | + } |
| 128 | + |
| 129 | + e.mu.Lock() |
| 130 | + defer e.mu.Unlock() |
| 131 | + |
| 132 | + e.log.Debug("subscribe", zap.String("topic", topic)) |
| 133 | + |
| 134 | + if !e.has(topic) { |
| 135 | + e.listeners[topic] = listeners |
| 136 | + } else { |
| 137 | + e.listeners[topic] = append(e.listeners[topic], listeners...) |
| 138 | + } |
| 139 | +} |
| 140 | + |
| 141 | +func (e *emitter) Once(topic string, listeners ...Listener) { |
| 142 | + e.log.Debug("subscribe once", zap.String("topic", topic)) |
| 143 | + e.On(topic, once(e, topic, listeners...)...) |
| 144 | +} |
| 145 | + |
| 146 | +func (e *emitter) OffListeners(topic string, listeners ...Listener) { |
| 147 | + e.mu.RLock() |
| 148 | + data, ok := e.listeners[topic] |
| 149 | + e.mu.RUnlock() |
| 150 | + |
| 151 | + if !ok { |
| 152 | + return |
| 153 | + } |
| 154 | + |
| 155 | + e.log.Debug("turn off listener for topic", zap.String("topic", topic)) |
| 156 | + |
| 157 | + if len(listeners) == 0 { |
| 158 | + e.mu.Lock() |
| 159 | + delete(e.listeners, topic) |
| 160 | + e.mu.Unlock() |
| 161 | + } else { |
| 162 | + ptrs := make(map[uintptr]bool, len(listeners)) |
| 163 | + for _, listener := range listeners { |
| 164 | + ptrs[reflect.ValueOf(listener).Pointer()] = true |
| 165 | + } |
| 166 | + |
| 167 | + newData := make([]Listener, 0) |
| 168 | + for _, listener := range data { |
| 169 | + if _, ok = ptrs[reflect.ValueOf(listener).Pointer()]; ok { |
| 170 | + continue |
| 171 | + } |
| 172 | + newData = append(newData, listener) |
| 173 | + } |
| 174 | + |
| 175 | + e.mu.Lock() |
| 176 | + if len(newData) == 0 { |
| 177 | + delete(e.listeners, topic) |
| 178 | + } else { |
| 179 | + e.listeners[topic] = newData |
| 180 | + } |
| 181 | + e.mu.Unlock() |
| 182 | + } |
| 183 | +} |
| 184 | + |
| 185 | +func (e *emitter) Off(topics ...string) { |
| 186 | + e.mu.Lock() |
| 187 | + defer e.mu.Unlock() |
| 188 | + |
| 189 | + e.log.Debug("turn off listeners", zap.Strings("topics", topics)) |
| 190 | + |
| 191 | + if len(topics) == 0 { |
| 192 | + e.listeners = make(map[string][]Listener) |
| 193 | + } else { |
| 194 | + for _, topic := range topics { |
| 195 | + if e.has(topic) { |
| 196 | + delete(e.listeners, topic) |
| 197 | + } |
| 198 | + } |
| 199 | + } |
| 200 | +} |
| 201 | + |
| 202 | +func (e *emitter) Emit(topic string, args ...any) error { |
| 203 | + e.mu.RLock() |
| 204 | + defer e.mu.RUnlock() |
| 205 | + |
| 206 | + if !e.has(topic) { |
| 207 | + return nil |
| 208 | + } |
| 209 | + |
| 210 | + e.log.Debug("emit event", zap.String("topic", topic), zap.Any("args", args)) |
| 211 | + |
| 212 | + event := Event{Topic: topic, Args: args} |
| 213 | + for _, listener := range e.listeners[topic] { |
| 214 | + if err := listener(&event); err != nil { |
| 215 | + return err |
| 216 | + } |
| 217 | + } |
| 218 | + return nil |
| 219 | +} |
| 220 | + |
| 221 | +func (e *emitter) Has(topic string) bool { |
| 222 | + e.mu.RLock() |
| 223 | + defer e.mu.RUnlock() |
| 224 | + |
| 225 | + return e.has(topic) |
| 226 | +} |
| 227 | + |
| 228 | +func (e *emitter) Listeners(topic string) []Listener { |
| 229 | + e.mu.RLock() |
| 230 | + defer e.mu.RUnlock() |
| 231 | + |
| 232 | + data := make([]Listener, 0) |
| 233 | + if listeners, ok := e.listeners[topic]; ok { |
| 234 | + for _, listener := range listeners { |
| 235 | + data = append(data, listener) |
| 236 | + } |
| 237 | + } |
| 238 | + return data |
| 239 | +} |
| 240 | + |
| 241 | +func (e *emitter) has(topic string) bool { |
| 242 | + _, ok := e.listeners[topic] |
| 243 | + return ok |
| 244 | +} |
0 commit comments