feat(runtime-vapor): KeepAlive (wip)

Author: ubugeeei

packages/runtime-vapor/src/component.ts

@@ -187,6 +187,7 @@ export interface ComponentInternalInstance {
   isMounted: boolean
   isUnmounted: boolean
   isUpdating: boolean
+  isDeactivated?: boolean
   // TODO: registory of provides, lifecycles, ...
   /**
    * @internal

packages/runtime-vapor/src/components/KeepAlive.ts

@@ -0,0 +1,230 @@
+import {
+  type Component,
+  type ComponentInternalInstance,
+  type ObjectComponent,
+  getCurrentInstance,
+} from '../component'
+import type { Block } from '../apiRender'
+import { invokeArrayFns, isArray, isRegExp, isString } from '@vue/shared'
+import { queuePostFlushCb } from '../scheduler'
+import { watch } from '../apiWatch'
+import { onBeforeUnmount, onMounted, onUpdated } from '../apiLifecycle'
+import { warn } from '..'
+
+type MatchPattern = string | RegExp | (string | RegExp)[]
+
+export interface KeepAliveProps {
+  include?: MatchPattern
+  exclude?: MatchPattern
+  max?: number | string
+}
+
+type CacheKey = PropertyKey | Component
+type Cache = Map<CacheKey, ComponentInternalInstance>
+type Keys = Set<CacheKey>
+
+// TODO: render coantext alternative
+export interface KeepAliveComponentInternalInstance
+  extends ComponentInternalInstance {
+  activate: () => void
+  deactivate: () => void
+}
+
+export const isKeepAlive = (instance: ComponentInternalInstance): boolean =>
+  (instance as any).__isKeepAlive
+
+const KeepAliveImpl: ObjectComponent = {
+  name: 'KeepAlive',
+
+  // @ts-expect-error
+  __isKeepAlive: true,
+
+  props: {
+    include: [String, RegExp, Array],
+    exclude: [String, RegExp, Array],
+    max: [String, Number],
+  },
+
+  setup(props: KeepAliveProps, { slots }) {
+    const instance = getCurrentInstance() as KeepAliveComponentInternalInstance
+
+    // TODO: ssr
+
+    const cache: Cache = new Map()
+    const keys: Keys = new Set()
+    let current: ComponentInternalInstance | null = null
+
+    // TODO: is it necessary?
+    // if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
+    //   ;(instance as any).__v_cache = cache
+    // }
+
+    // TODO: suspense
+    // const parentSuspense = instance.suspense
+
+    // TODO:
+    // const storageContainer = template('<div></div>')()
+
+    instance.activate = () => {
+      // TODO:
+      // move(vnode, container, anchor, MoveType.ENTER, parentSuspense)
+
+      // TODO: suspense (queuePostRenderEffect)
+      queuePostFlushCb(() => {
+        instance.isDeactivated = false
+        if (instance.a) {
+          invokeArrayFns(instance.a)
+        }
+      })
+
+      // TODO: devtools
+      // if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
+      //   // Update components tree
+      //   devtoolsComponentAdded(instance)
+      // }
+    }
+
+    instance.deactivate = () => {
+      // TODO:
+      // invalidateMount(instance.m)
+      // invalidateMount(instance.a)
+      // move(vnode, storageContainer, null, MoveType.LEAVE, parentSuspense)
+
+      // TODO: suspense (queuePostRenderEffect)
+      queuePostFlushCb(() => {
+        if (instance.da) {
+          invokeArrayFns(instance.da)
+        }
+        instance.isDeactivated = true
+      })
+
+      // TODO: devtools
+      // if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
+      //   // Update components tree
+      //   devtoolsComponentAdded(instance)
+      // }
+    }
+
+    function pruneCache(filter?: (name: string) => boolean) {
+      cache.forEach((cachedInstance, key) => {
+        const name = cachedInstance.type.name
+        if (name && (!filter || !filter(name))) {
+          pruneCacheEntry(key)
+        }
+      })
+    }
+
+    function pruneCacheEntry(key: CacheKey) {
+      const cached = cache.get(key)
+      if (!current || cached !== current) {
+        // TODO:
+        // 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.
+        // TODO:
+        // resetShapeFlag(current)
+      }
+      cache.delete(key)
+      keys.delete(key)
+    }
+
+    // prune cache on include/exclude prop change
+    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 },
+    )
+
+    // cache sub tree after render
+    let pendingCacheKey: CacheKey | null = null
+    const cacheSubtree = () => {
+      // fix #1621, the pendingCacheKey could be 0
+      if (pendingCacheKey != null) {
+        cache.set(pendingCacheKey, instance)
+      }
+    }
+    onMounted(cacheSubtree)
+    onUpdated(cacheSubtree)
+
+    onBeforeUnmount(() => {
+      // TODO:
+    })
+
+    // TODO: effects
+    return () => {
+      pendingCacheKey = null
+
+      if (!slots.default) {
+        return null
+      }
+
+      const children = slots.default()
+      const childInstance = children as ComponentInternalInstance
+      if (isArray(children) && children.length > 1) {
+        if (__DEV__) {
+          warn(`KeepAlive should contain exactly one component child.`)
+        }
+        current = null
+        return children
+      } else {
+        // TODO:
+      }
+
+      const name = childInstance.type.name
+      const { include, exclude, max } = props
+
+      if (
+        (include && (!name || !matches(include, name))) ||
+        (exclude && name && matches(exclude, name))
+      ) {
+        return (current = childInstance)
+      }
+
+      const key = childInstance.type // TODO: vnode key
+      const cachedBlock = cache.get(key)
+
+      pendingCacheKey = key
+
+      if (cachedBlock) {
+        // TODO: setTransitionHooks
+
+        keys.delete(key)
+        keys.add(key)
+      } else {
+        keys.add(key)
+        if (max && keys.size > parseInt(max as string, 10)) {
+          pruneCacheEntry(keys.values().next().value)
+        }
+      }
+
+      return (current = childInstance)
+    }
+  },
+}
+
+export const KeepAlive = KeepAliveImpl as any as {
+  __isKeepAlive: true
+  new (): {
+    $props: KeepAliveProps
+    $slots: {
+      default(): Block
+    }
+  }
+}
+
+function matches(pattern: MatchPattern, name: string): boolean {
+  if (isArray(pattern)) {
+    return pattern.some((p: string | RegExp) => matches(p, name))
+  } else if (isString(pattern)) {
+    return pattern.split(',').includes(name)
+  } else if (isRegExp(pattern)) {
+    return pattern.test(name)
+  }
+  /* istanbul ignore next */
+  return false
+}