38 lines
912 B
JavaScript
38 lines
912 B
JavaScript
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class MyEvent {
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constructor() {
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// 使用 Object 或 Map 存储，实现 O(1) 级别的查找
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this.events = new Map()
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}
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add(name, call) {
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if (!this.events.has(name)) {
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this.events.set(name, [])
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}
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this.events.get(name).push(call)
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}
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remove(name, call) {
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if (!this.events.has(name)) return
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if (!call) {
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this.events.delete(name)
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} else {
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const callbacks = this.events.get(name)
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const index = callbacks.indexOf(call)
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if (index !== -1) {
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callbacks.splice(index, 1)
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}
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// 如果该事件没有监听者了，彻底清理 key
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if (callbacks.length === 0) {
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this.events.delete(name)
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}
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}
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}
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emit(name, data) {
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const callbacks = this.events.get(name)
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if (callbacks) {
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// 使用 slice() 镜像一份副本，防止在执行回调过程中有 remove 操作导致索引错乱
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callbacks.slice().forEach((cb) => cb(data))
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}
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}
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}
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export default new MyEvent()
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