<template>
        <router-view v-slot="{ Component }">
            <keep-alive :include="keepAliveCache">
                <component :is="Component" :key="$route.name" />
            </keep-alive>
        </router-view>
    </template>
    <script lang="ts" setup>
    import { computed } from "vue";
    import { useKeepAliverStore } from "@/store";
    const useStore = useKeepAliverStore();
    const keepAliveCache = computed(() => {
        return useStore.caches;
    });
    </script>

    import { defineStore } from "pinia";
    export const useKeepAliverStore = defineStore("useKeepAliverStore", {
        state: () => ({
            caches: [] as any,
            scrollList: new Map(),  // 緩存頁面組件如果又滾動(dòng)條的高度
        }),
        actions: {
            add(name: string) {
                this.caches.push(name);
            },
            remove(name: string) {
                console.log(this.caches, 'this.caches')
                this.caches = this.caches.filter((item: any) => item !== name);
                console.log(this.caches, 'this.caches')
            },
            clear() {
                this.caches = []
            }
        }
    });

    import { useRoute, useRouter, onBeforeRouteLeave } from "vue-router";
    import { useKeepAliverStore } from "@/store";
    const useStore = useKeepAliverStore()
    export default {
        name:"record-month",
        beforeRouteEnter(to, from, next) {
            next(vm => {
                if(from.name === 'Home' && to.name === 'record-month') {
                useStore.add(to.name)
                }
            });
        }
    }
    </script>

    onBeforeRouteLeave((to, from) => {
        console.log(to.name, "onBeforeRouteLeave");
        if (to.name === "new-detection-detail") {
            console.log(to, from, "進(jìn)入詳情頁面不做處理");
        } else {
            useStore.remove(from.name)
            console.log(to, from, "刪除組件緩存");
        }
    });

    onActivated(() => {
        if(useStore.scrollList.get(routeName)) {
            const top = useStore.scrollList.get(routeName)
            refList.value.setScrollTop(Number(top))
        }
    });
    onDeactivated(() => {
        const top = refList.value.getScrollTop()
        useStore.scrollList.set(routeName, top)
    });

    const setScrollTop = (value: any) => {
        const dom = document.querySelector('.van-pull-refresh')
        dom!.scrollTop = value
    }

    onMounted(() => {
        scrollDom.value = document.querySelector('.van-pull-refresh') as HTMLElement
        const throttledFun = useThrottleFn(() => {
            console.log(scrollDom.value?.scrollTop, 'addEventListener')
            state.scrollTop = scrollDom.value!.scrollTop
        }, 500)
        if(scrollDom.value) {
            scrollDom.value.addEventListener('scroll',throttledFun)
        }
    })
    const getScrollTop = () => {
        console.log('scrollDom.vaue', scrollDom.value?.scrollTop)
        return state.scrollTop
    }

    https://vueuse.org/shared/usethrottlefn/#usethrottlefn

    const instance = getCurrentInstance()
    console.log(instance.vnode.parent) // 這里便是keepalive組件vnode
    // 如果是在開發(fā)環(huán)境中可以查看到cache對(duì)象
    instance.vnode.parent.__v_cache
    // vue源碼中，在dev環(huán)境對(duì)cache進(jìn)行暴露，生產(chǎn)環(huán)境是看不到的
    if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
        ;(instance as any).__v_cache = cache
    }

    git clone git@github.com:vuejs/core.git

    pnpm i

    npm i pnpm -g

    // 在dev命令后添加 --source-map是從已轉(zhuǎn)換的代碼，映射到原始的源文件
    "dev": "node scripts/dev.js  --sourcemap"

    pnpm run dev
    //則會(huì)出現(xiàn)以下，代表成功了（2022年5月27日），后期vue源代碼作者可能會(huì)更新，相應(yīng)的提示可能發(fā)生變更，請(qǐng)注意一下
    > @3.2.36 dev H:\github\sourceCode\core
    > node scripts/dev.js  --sourcemap
    watching: packages\vue\dist\vue.global.js
    //到..\..\core\packages\vue\dist便可以看到編譯成功，以及可以查看到examples樣例demo頁面

    <script src="../../dist/vue.global.js"></script>
    <script type="text/x-template" id="template-1">
        <div>template-1</div>
        <div>template-1</div>
    </script>
    <script type="text/x-template" id="template-2">
        <div>template-2</div>
        <div>template-2</div>
    </script>
    <script>
    const { reactive, computed } = Vue
    const Demo1 = {
        name: 'Demo1',
        template: '#template-1',
        setup(props) {
        }
    }
    const Demo2 = {
        name: 'Demo2',
        template: '#template-2',
        setup(props) {
        }
    }
    </script>
    <!-- App template (in DOM) -->
    <div id="demo">
        <div>Hello World</div>
        <div>Hello World</div>
        <div>Hello World</div>
        <button @click="changeClick(1)">組件一</button>
        <button @click="changeClick(2)">組件二</button>
        <keep-alive :include="includeCache">
            <component :is="componentCache" :key="componentName" v-if="componentName" />
        </keep-alive>
    </div>
    <!-- App script -->
    <script>
    Vue.createApp({
    components: {
        Demo1,
        Demo2
    },
    data: () => ({
        includeCache: [],
        componentCache: '',
        componentName: '',
    }),
    methods:{
        changeClick(type) {
            if(type === 1) {
                if(!this.includeCache.includes('Demo1')) {
                    this.includeCache.push('Demo1')
                }
                console.log(this.includeCache, '000')
                this.componentCache = Demo1
                this.componentName = 'Demo1'
            }
            if(type === 2) {
                if(!this.includeCache.includes('Demo2')) {
                    this.includeCache.push('Demo2')
                }
                console.log(this.includeCache, '2222')
                this.componentName = 'Demo2'
                this.componentCache = Demo2
            }
        }
    }
    }).mount('#demo')
    </script>

    // 在setup初始化中，先獲取keepalive實(shí)例
    // getCurrentInstance() 可以獲取當(dāng)前組件的實(shí)例
    const instance = getCurrentInstance()!
    // KeepAlive communicates with the instantiated renderer via the
    // ctx where the renderer passes in its internals,
    // and the KeepAlive instance exposes activate/deactivate implementations.
    // The whole point of this is to avoid importing KeepAlive directly in the
    // renderer to facilitate tree-shaking.
    const sharedContext = instance.ctx as KeepAliveContext
    // if the internal renderer is not registered, it indicates that this is server-side rendering,
    // for KeepAlive, we just need to render its children
    /// SSR 判斷，暫時(shí)可以忽略掉即可。
    if (__SSR__ && !sharedContext.renderer) {
        return () => {
            const children = slots.default && slots.default()
            return children && children.length === 1 ? children[0] : children
        }
    }
    // 通過Map存儲(chǔ)緩存vnode,
    // 通過Set存儲(chǔ)緩存的key(在外面設(shè)置的key，或者vnode的type)
    const cache: Cache = new Map()
    const keys: Keys = new Set()
    let current: VNode | null = null
    if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
    ;(instance as any).__v_cache = cache
    }
    const parentSuspense = instance.suspense
    const {
    renderer: {
        p: patch,
        m: move,
        um: _unmount,
        o: { createElement }
    }
    } = sharedContext
    // 創(chuàng)建了隱藏容器
    const storageContainer = createElement('div')
    // 在實(shí)例上注冊(cè)兩個(gè)鉤子函數(shù) activate，  deactivate
    sharedContext.activate = (vnode, container, anchor, isSVG, optimized) => {
        const instance = vnode.component!
        move(vnode, container, anchor, MoveType.ENTER, parentSuspense)
        // in case props have changed
        patch(
            instance.vnode,
            vnode,
            container,
            anchor,
            instance,
            parentSuspense,
            isSVG,
            vnode.slotScopeIds,
            optimized
        )
        queuePostRenderEffect(() => {
            instance.isDeactivated = false
            if (instance.a) {
            invokeArrayFns(instance.a)
            }
            const vnodeHook = vnode.props && vnode.props.onVnodeMounted
            if (vnodeHook) {
            invokeVNodeHook(vnodeHook, instance.parent, vnode)
            }
        }, parentSuspense)
        if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
            // Update components tree
            devtoolsComponentAdded(instance)
        }
    }
    sharedContext.deactivate = (vnode: VNode) => {
        const instance = vnode.component!
        move(vnode, storageContainer, null, MoveType.LEAVE, parentSuspense)
        queuePostRenderEffect(() => {
            if (instance.da) {
            invokeArrayFns(instance.da)
            }
            const vnodeHook = vnode.props && vnode.props.onVnodeUnmounted
            if (vnodeHook) {
            invokeVNodeHook(vnodeHook, instance.parent, vnode)
            }
            instance.isDeactivated = true
        }, parentSuspense)
        if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
            // Update components tree
            devtoolsComponentAdded(instance)
        }
    }
    // 組件卸載
    function unmount(vnode: VNode) {
        // reset the shapeFlag so it can be properly unmounted
        resetShapeFlag(vnode)
        _unmount(vnode, instance, parentSuspense, true)
    }
    // 定義 include和exclude變化時(shí)，對(duì)緩存進(jìn)行動(dòng)態(tài)處理
    function pruneCache(filter?: (name: string) => boolean) {
        cache.forEach((vnode, key) => {
            const name = getComponentName(vnode.type as ConcreteComponent)
            if (name && (!filter || !filter(name))) {
            pruneCacheEntry(key)
            }
        })
    }
    function pruneCacheEntry(key: CacheKey) {
        const cached = cache.get(key) as VNode
        if (!current || cached.type !== current.type) {
            unmount(cached)
        } else if (current) {
            // current active instance should no longer be kept-alive.
            // we can't unmount it now but it might be later, so reset its flag now.
            resetShapeFlag(current)
        }
        cache.delete(key)
        keys.delete(key)
    }
    // 可以發(fā)現(xiàn)通過include 可以配置被顯示的組件，
    // 當(dāng)然也可以設(shè)置exclude來配置不被顯示的組件,
    // 組件切換時(shí)隨時(shí)控制緩存
    watch(
    () => [props.include, props.exclude],
    ([include, exclude]) => {
        include && pruneCache(name => matches(include, name))
        exclude && pruneCache(name => !matches(exclude, name))
    },
    // prune post-render after `current` has been updated
    { flush: 'post', deep: true }
    )
    // 定義當(dāng)前組件Key
    // cache sub tree after render
        let pendingCacheKey: CacheKey | null = null
        // 這是一個(gè)重要的方法，設(shè)置緩存
        const cacheSubtree = () => {
        // fix #1621, the pendingCacheKey could be 0
        if (pendingCacheKey != null) {
            cache.set(pendingCacheKey, getInnerChild(instance.subTree))
        }
        }
        onMounted(cacheSubtree)
        onUpdated(cacheSubtree)
        // 組件卸載的時(shí)候，對(duì)緩存列表進(jìn)行循環(huán)判斷處理
        onBeforeUnmount(() => {
            cache.forEach(cached => {
                const { subTree, suspense } = instance
                const vnode = getInnerChild(subTree)
                if (cached.type === vnode.type) {
                // current instance will be unmounted as part of keep-alive's unmount
                resetShapeFlag(vnode)
                // but invoke its deactivated hook here
                const da = vnode.component!.da
                da && queuePostRenderEffect(da, suspense)
                return
                }
                unmount(cached)
            })
        })
    // 同時(shí)在keepAlive組件setup生命周期中，return () => {} 渲染的時(shí)候，對(duì)組件進(jìn)行判斷邏輯處理，同樣對(duì)include和exclude判斷渲染。
    // 判斷keepalive組件中的子組件，如果大于1個(gè)的話，直接警告處理了
    // 另外如果渲染的不是虛擬dom（vNode）,則直接返回渲染即可。
    return () => {
        // eslint-disable-next-line no-debugger
        console.log(props.include, 'watch-include')
        pendingCacheKey = null
        if (!slots.default) {
            return null
        }
        const children = slots.default()
        const rawVNode = children[0]
        if (children.length > 1) {
            if (__DEV__) {
            warn(`KeepAlive should contain exactly one component child.`)
            }
            current = null
            return children
        } else if (
            !isVNode(rawVNode) ||
            (!(rawVNode.shapeFlag & ShapeFlags.STATEFUL_COMPONENT) &&
            !(rawVNode.shapeFlag & ShapeFlags.SUSPENSE))
        ) {
            current = null
            return rawVNode
        }
        // 接下來處理時(shí)Vnode虛擬dom的情況，先獲取vnode
        let vnode = getInnerChild(rawVNode)
        // 節(jié)點(diǎn)類型
        const comp = vnode.type as ConcreteComponent
        // for async components, name check should be based in its loaded
        // inner component if available
        // 獲取組件名稱
        const name = getComponentName(
            isAsyncWrapper(vnode)
            ? (vnode.type as ComponentOptions).__asyncResolved || {}
            : comp
        )
        //這個(gè)算是最熟悉的通過props傳遞進(jìn)行的參數(shù)，進(jìn)行解構(gòu)
        const { include, exclude, max } = props
        // include判斷 組件名稱如果沒有設(shè)置， 或者組件名稱不在include中，
        // exclude判斷 組件名稱有了，或者匹配了
        // 對(duì)以上兩種情況都不進(jìn)行緩存處理，直接返回當(dāng)前vnode虛擬dom即可。
        if (
            (include && (!name || !matches(include, name))) ||
            (exclude && name && matches(exclude, name))
        ) {
            current = vnode
            return rawVNode
        }
        // 接下來開始處理有緩存或者要緩存的了
        // 先獲取一下vnode的key設(shè)置，然后看看cache緩存中是否存在
        const key = vnode.key == null ? comp : vnode.key
        const cachedVNode = cache.get(key)
        // 這一段可以忽略了，好像時(shí)ssContent相關(guān)，暫時(shí)不管了，沒看明白？？
        // clone vnode if it's reused because we are going to mutate it
        if (vnode.el) {
            vnode = cloneVNode(vnode)
            if (rawVNode.shapeFlag & ShapeFlags.SUSPENSE) {
            rawVNode.ssContent = vnode
            }
        }
        // 上面判斷了，如果沒有設(shè)置key，則使用vNode的type作為key值
        pendingCacheKey = key
        //判斷上面緩存中是否存在vNode
        // if 存在的話，就將緩存中的vnode復(fù)制給當(dāng)前的vnode
        // 同時(shí)還判斷了組件是否為過渡組件 transition，如果是的話 需要注冊(cè)過渡組件的鉤子
        // 同時(shí)先刪除key，然后再重新添加key
        // else 不存在的話，就添加到緩存即可
        // 并且要判斷一下max最大緩存的數(shù)量是否超過了，超過了，則通過淘汰LPR算法，刪除最舊的一個(gè)緩存
        // 最后又判斷了一下是否為Suspense。也是vue3新增的高階組件。
        if (cachedVNode) {
            // copy over mounted state
            vnode.el = cachedVNode.el
            vnode.component = cachedVNode.component
            if (vnode.transition) {
            // recursively update transition hooks on subTree
            setTransitionHooks(vnode, vnode.transition!)
            }
            // avoid vnode being mounted as fresh
            vnode.shapeFlag |= ShapeFlags.COMPONENT_KEPT_ALIVE
            // make this key the freshest
            keys.delete(key)
            keys.add(key)
        } else {
            keys.add(key)
            // prune oldest entry
            if (max && keys.size > parseInt(max as string, 10)) {
            pruneCacheEntry(keys.values().next().value)
            }
        }
        // avoid vnode being unmounted
        vnode.shapeFlag |= ShapeFlags.COMPONENT_SHOULD_KEEP_ALIVE
        current = vnode
        return isSuspense(rawVNode.type) ? rawVNode : vnode