优化ObservableImpl

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2025-09-17 09:58:27 +08:00
parent 122fba228a
commit 6eee4933e1

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@@ -10,68 +10,69 @@ import type {
* 创建一个可观察对象,用于管理状态和事件。 * 创建一个可观察对象,用于管理状态和事件。
* @template T - 需要处理的状态类型 * @template T - 需要处理的状态类型
* @example * @example
* interface Todo {
* id: number
* text: string
* done: boolean
* }
*
* interface AppState { * interface AppState {
* count: number * count: number
* todos: Todo[]
* user: { * user: {
* name: string * name: string
* age: number * age: number
* } * }
* items: number[] * inc(): void
* } * }
* *
* // 创建 ObservableImpl
* const obs = new ObservableImpl<AppState>({ * const obs = new ObservableImpl<AppState>({
* count: 0, * count: 0,
* user: { name: 'Alice', age: 20 }, * todos: [],
* items: [] * user: { name: "Alice", age: 20 },
* inc() {
* this.count++ // ✅ this 指向 obs.state
* },
* }) * })
* *
* // 1⃣ 全量订阅 * // ================== 使用示例 ==================
* const unsubscribeAll = obs.subscribe(state => {
* console.log('全量订阅', state)
* }, { immediate: true })
* *
* // 2⃣ 单字段订阅 * // 1. 订阅整个 state
* const unsubscribeCount = obs.subscribeKey('count', ({ count }) => { * obs.subscribe(state => {
* console.log('count 字段变化:', count) * console.log("[全量订阅] state 更新:", state)
* }) * })
* *
* // 3⃣ 多字段订阅 * // 2. 订阅单个字段
* const unsubscribeUser = obs.subscribeKey(['user', 'count'], ({ user, count }) => { * obs.subscribeKey("count", ({ count }) => {
* console.log('user 或 count 变化:', { user, count }) * console.log("[字段订阅] count 更新:", count)
* }) * })
* *
* // 4⃣ 修改属性 * // 3. 订阅多个字段
* obs.state.count = 1 // ✅ 会触发 count 和全量订阅 * obs.subscribeKey(["name", "age"] as (keyof AppState["user"])[], (user) => {
* obs.state.user.age = 21 // ✅ 深层对象修改触发 user 订阅 * console.log("[多字段订阅] user 更新:", user)
* obs.state.user.name = 'Bob'
* // 语法糖:解构赋值直接赋值触发通知
* const { count, user, items } = obs.toRefsProxy()
* count = 1 // 触发 Proxy set
* user.age = 18 // 深层对象 Proxy 支持
* items.push(42) // 数组方法拦截触发通知
*
* // 5⃣ 数组方法触发
* obs.state.items.push(10) // ✅ push 会触发 items 的字段订阅
* obs.state.items.splice(0, 1)
*
* // 6⃣ 批量修改(同一事件循环只触发一次通知)
* obs.patch({
* count: 2,
* user: { name: 'Charlie', age: 30 }
* }) * })
* *
* // 7⃣ 解构赋值访问对象属性仍然触发订阅 * // 4. 批量更新
* const { state } = obs * obs.patch({ count: 10, user: { name: "Bob", age: 30 } })
* state.user.age = 31 // ✅ 会触发 user 订阅
* *
* // 8⃣ 取消订阅 * // 5. 方法里操作 state
* unsubscribeAll() * obs.state.inc() // this.count++ → 相当于 obs.state.count++
* unsubscribeCount()
* unsubscribeUser()
* *
* // 9⃣ 销毁 ObservableImpl * // 6. 数组操作
* obs.dispose() * obs.subscribeKey("todos", ({ todos }) => {
* console.log("[数组订阅] todos 更新:", todos.map(t => t.text))
* })
*
* obs.state.todos.push({ id: 1, text: "Buy milk", done: false })
* obs.state.todos.push({ id: 2, text: "Read book", done: false })
* obs.state.todos[0].done = true
*
* // 7. 嵌套对象
* obs.subscribeKey("user", ({ user }) => {
* console.log("[嵌套订阅] user 更新:", user)
* })
*
* obs.state.user.age++
*/ */
export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObservable<T> { export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObservable<T> {
/** Observable 状态对象,深层 Proxy */ /** Observable 状态对象,深层 Proxy */
@@ -81,7 +82,7 @@ export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObs
private listeners: Set<TObservableListener<T>> = new Set() private listeners: Set<TObservableListener<T>> = new Set()
/** 字段订阅函数集合 */ /** 字段订阅函数集合 */
private keyListeners: Map<keyof T, Set<Function>> = new Map() private keyListeners: Map<keyof T, Set<TObservableKeyListener<T, keyof T>>> = new Map()
/** 待通知的字段集合 */ /** 待通知的字段集合 */
private pendingKeys: Set<keyof T> = new Set() private pendingKeys: Set<keyof T> = new Set()
@@ -92,56 +93,73 @@ export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObs
/** 是否已销毁 */ /** 是否已销毁 */
private disposed = false private disposed = false
/** 缓存 Proxy避免重复包装 */
private proxyCache: WeakMap<object, TObservableState<unknown>> = new WeakMap()
constructor(initialState: TNonFunctionProperties<T>) { constructor(initialState: TNonFunctionProperties<T>) {
// 创建深层响应式 Proxy // 创建深层响应式 Proxy
this.state = this.makeReactive(initialState) as TObservableState<T> this.state = this.makeReactive(initialState) as TObservableState<T>
} }
/** 创建深层 Proxy拦截 get/set */ /** 创建深层 Proxy拦截 get/set/delete并自动缓存 */
private makeReactive(obj: TNonFunctionProperties<T>): TObservableState<T> { private makeReactive<O extends object>(obj: O): TObservableState<O> {
const handler: ProxyHandler<any> = { // 非对象直接返回(包括 null 已被排除)
get: (target, prop: string | symbol, receiver) => { if (typeof obj !== "object" || obj === null) {
const key = prop as keyof T return obj as unknown as TObservableState<O>
const value = Reflect.get(target, key, receiver) }
if (Array.isArray(value)) return this.wrapArray(value, key)
if (typeof value === 'object' && value !== null) return this.makeReactive(value) // 如果已有 Proxy 缓存则直接返回
const cached = this.proxyCache.get(obj as object)
if (cached !== undefined) {
return cached as TObservableState<O>
}
const handler: ProxyHandler<O> = {
get: (target, prop, receiver) => {
const value = Reflect.get(target, prop, receiver) as unknown
// 不包装函数
if (typeof value === "function") {
return value
}
// 对对象/数组继续进行响应式包装(递归)
if (typeof value === "object" && value !== null) {
return this.makeReactive(value as object)
}
return value return value
}, },
set: (target, prop: string | symbol, value, receiver) => {
const key = prop as keyof T set: (target, prop, value, receiver) => {
const oldValue = target[key] // 读取旧值(使用 Record 以便类型安全访问属性)
if (oldValue !== value) { const oldValue = (target as Record<PropertyKey, unknown>)[prop as PropertyKey] as unknown
target[key] = value const result = Reflect.set(target, prop, value as unknown, receiver)
this.pendingKeys.add(key) // 仅在值改变时触发通知(基于引用/原始值比较)
if (!this.disposed && oldValue !== (value as unknown)) {
this.pendingKeys.add(prop as keyof T)
this.scheduleNotify() this.scheduleNotify()
} }
return true return result
},
deleteProperty: (target, prop) => {
if (prop in target) {
// 使用 Reflect.deleteProperty 以保持一致性
const deleted = Reflect.deleteProperty(target, prop)
if (deleted && !this.disposed) {
this.pendingKeys.add(prop as keyof T)
this.scheduleNotify()
}
return deleted
}
return false
} }
} }
return new Proxy(obj, handler) as TObservableState<T>
const proxy = new Proxy(obj, handler) as TObservableState<O>
this.proxyCache.set(obj as object, proxy as TObservableState<unknown>)
return proxy
} }
/** 包装数组方法,使 push/pop 等触发通知 */ /** 安排下一次通知(微任务合并) */
private wrapArray(arr: any[], parentKey: keyof T): any {
const self = this
const arrayMethods = ['push', 'pop', 'shift', 'unshift', 'splice', 'sort', 'reverse'] as const
arrayMethods.forEach(method => {
const original = arr[method]
Object.defineProperty(arr, method, {
value: function (...args: any[]) {
const result = original.apply(this, args)
self.pendingKeys.add(parentKey)
self.scheduleNotify()
return result
},
writable: true,
configurable: true,
})
})
return arr
}
/** 安排下一次通知 */
private scheduleNotify(): void { private scheduleNotify(): void {
if (!this.notifyScheduled && !this.disposed) { if (!this.notifyScheduled && !this.disposed) {
this.notifyScheduled = true this.notifyScheduled = true
@@ -149,40 +167,70 @@ export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObs
} }
} }
/** 执行通知 */ /** 执行通知(聚合字段订阅并保证错误隔离) */
private flushNotify(): void { private flushNotify(): void {
if (this.disposed) return if (this.disposed) return
const keys = Array.from(this.pendingKeys) const keys = Array.from(this.pendingKeys)
this.pendingKeys.clear() this.pendingKeys.clear()
this.notifyScheduled = false this.notifyScheduled = false
// 全量订阅 // 全量订阅 —— 每个订阅单独 try/catch避免一个错误阻塞其它订阅
for (const fn of this.listeners) { for (const fn of Array.from(this.listeners)) {
fn(this.state) try {
} fn(this.state as unknown as T)
} catch (err) {
// 字段订阅 // 可以根据需要把错误上报或自定义处理
const fnMap = new Map<Function, (keyof T)[]>() // 这里简单打印以便调试
for (const key of keys) { // eslint-disable-next-line no-console
const set = this.keyListeners.get(key) console.error("Observable listener error:", err)
if (!set) continue
for (const fn of set) {
if (!fnMap.has(fn)) fnMap.set(fn, [])
fnMap.get(fn)!.push(key)
} }
} }
// 字段订阅:把同一个回调的多个 key 聚合到一次调用里
const fnMap: Map<TObservableKeyListener<T, keyof T>, (keyof T)[]> = new Map()
for (const key of keys) {
const set = this.keyListeners.get(key)
if (!set) continue
for (const fn of Array.from(set)) {
const existing = fnMap.get(fn)
if (existing === undefined) {
fnMap.set(fn, [key])
} else {
existing.push(key)
}
}
}
// 调用每个字段订阅回调
fnMap.forEach((subKeys, fn) => { fnMap.forEach((subKeys, fn) => {
const result = {} as Pick<T, typeof subKeys[number]> try {
subKeys.forEach(k => (result[k] = this.state[k])) // 构造 Pick<T, K> 风格的结果对象:结果类型为 Pick<T, (typeof subKeys)[number]>
fn(result) const result = {} as Pick<T, (typeof subKeys)[number]>
subKeys.forEach(k => {
// 这里断言原因state 的索引访问返回 unknown但我们把它赋回到受限的 Pick 上
result[k] = (this.state as Record<keyof T, unknown>)[k] as T[(typeof k) & keyof T]
})
// 调用时类型上兼容 TObservableKeyListener<T, K>,因为我们传的是对应 key 的 Pick
fn(result as unknown as any) // 最后一处转换仅为满足 TypeScript 调用签名(不引入 any 到实现变量)
} catch (err) {
// eslint-disable-next-line no-console
console.error("Observable keyListener error:", err)
}
}) })
} }
/** 订阅整个状态变化 */ /** 订阅整个状态变化 */
public subscribe(fn: TObservableListener<T>, options: { immediate?: boolean } = {}): () => void { public subscribe(fn: TObservableListener<T>, options: { immediate?: boolean } = {}): () => void {
this.listeners.add(fn) this.listeners.add(fn)
if (options.immediate) fn(this.state) if (options.immediate) {
try {
fn(this.state as unknown as T)
} catch (err) {
// eslint-disable-next-line no-console
console.error("Observable subscribe immediate error:", err)
}
}
return () => { return () => {
this.listeners.delete(fn) this.listeners.delete(fn)
} }
@@ -197,32 +245,48 @@ export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObs
const keyArray = Array.isArray(keys) ? keys : [keys] const keyArray = Array.isArray(keys) ? keys : [keys]
for (const key of keyArray) { for (const key of keyArray) {
if (!this.keyListeners.has(key)) this.keyListeners.set(key, new Set()) if (!this.keyListeners.has(key)) this.keyListeners.set(key, new Set())
this.keyListeners.get(key)!.add(fn) // 存储为 Set<TObservableKeyListener<T, keyof T>>
this.keyListeners.get(key)!.add(fn as TObservableKeyListener<T, keyof T>)
} }
if (options.immediate) { if (options.immediate) {
const result = {} as Pick<T, K> const result = {} as Pick<T, K>
keyArray.forEach(k => (result[k] = this.state[k])) keyArray.forEach(k => {
fn(result) result[k] = (this.state as Record<keyof T, unknown>)[k] as T[K]
})
try {
fn(result)
} catch (err) {
// eslint-disable-next-line no-console
console.error("Observable subscribeKey immediate error:", err)
}
} }
return () => { return () => {
for (const key of keyArray) { for (const key of keyArray) {
this.keyListeners.get(key)?.delete(fn) this.keyListeners.get(key)?.delete(fn as TObservableKeyListener<T, keyof T>)
} }
} }
} }
/** 批量更新状态 */ /** 批量更新状态(避免重复 schedule */
public patch(values: Partial<T>): void { public patch(values: Partial<T>): void {
let changed = false
// 用 for..in 保持和对象字面量兼容(跳过原型链)
for (const key in values) { for (const key in values) {
if (Object.prototype.hasOwnProperty.call(values, key)) { if (Object.prototype.hasOwnProperty.call(values, key)) {
const typedKey = key as keyof T const typedKey = key as keyof T
this.state[typedKey] = values[typedKey]! const oldValue = (this.state as Record<keyof T, unknown>)[typedKey]
this.pendingKeys.add(typedKey) const newValue = values[typedKey] as unknown
if (oldValue !== newValue) {
// 直接写入 state会被 Proxy 的 set 捕获并安排通知
;(this.state as Record<keyof T, unknown>)[typedKey] = newValue
changed = true
}
} }
} }
this.scheduleNotify() // 如果至少有一处变化,安排一次通知(如果写入已由 set 调度过也不会重复安排)
if (changed) this.scheduleNotify()
} }
/** 销毁 Observable 实例 */ /** 销毁 Observable 实例 */
@@ -231,27 +295,29 @@ export class ObservableImpl<T extends TNonFunctionProperties<T>> implements IObs
this.listeners.clear() this.listeners.clear()
this.keyListeners.clear() this.keyListeners.clear()
this.pendingKeys.clear() this.pendingKeys.clear()
this.proxyCache = new WeakMap()
} }
/** 语法糖:返回一个可解构赋值的 Proxy */ /** 语法糖:返回一个可解构赋值的 Proxy */
public toRefsProxy(): { [K in keyof T]: T[K] } { public toRefsProxy(): { [K in keyof T]: T[K] } {
const self = this const self = this
return new Proxy({} as T, { return new Proxy({} as { [K in keyof T]: T[K] }, {
get(_, prop: string | symbol) { get(_, prop: string | symbol) {
const key = prop as keyof T const key = prop as keyof T
return self.state[key] return (self.state as Record<keyof T, unknown>)[key] as T[typeof key]
}, },
set(_, prop: string | symbol, value) { set(_, prop: string | symbol, value) {
const key = prop as keyof T const key = prop as keyof T
self.state[key] = value ;(self.state as Record<keyof T, unknown>)[key] = value as unknown
return true return true
}, },
ownKeys() { ownKeys() {
return Reflect.ownKeys(self.state) return Reflect.ownKeys(self.state)
}, },
getOwnPropertyDescriptor(_, prop: string | symbol) { getOwnPropertyDescriptor(_, _prop: string | symbol) {
return { enumerable: true, configurable: true } return { enumerable: true, configurable: true }
} }
}) })
} }
} }