vue3-yuanma/packages/runtime-core/src/scheduler.ts

97 lines
2.1 KiB
TypeScript

import { ErrorCodes, callWithErrorHandling } from './errorHandling'
import { isArray } from '@vue/shared'
const queue: Function[] = []
const postFlushCbs: Function[] = []
const p = Promise.resolve()
let isFlushing = false
let isFlushPending = false
const RECURSION_LIMIT = 100
type CountMap = Map<Function, number>
export function nextTick(fn?: () => void): Promise<void> {
return fn ? p.then(fn) : p
}
export function queueJob(job: () => void) {
if (!queue.includes(job)) {
queue.push(job)
queueFlush()
}
}
export function queuePostFlushCb(cb: Function | Function[]) {
if (!isArray(cb)) {
postFlushCbs.push(cb)
} else {
postFlushCbs.push(...cb)
}
queueFlush()
}
function queueFlush() {
if (!isFlushing && !isFlushPending) {
isFlushPending = true
nextTick(flushJobs)
}
}
const dedupe = (cbs: Function[]): Function[] => [...new Set(cbs)]
export function flushPostFlushCbs(seen?: CountMap) {
if (postFlushCbs.length) {
const cbs = dedupe(postFlushCbs)
postFlushCbs.length = 0
if (__DEV__) {
seen = seen || new Map()
}
for (let i = 0; i < cbs.length; i++) {
if (__DEV__) {
checkRecursiveUpdates(seen!, cbs[i])
}
cbs[i]()
}
}
}
function flushJobs(seen?: CountMap) {
isFlushPending = false
isFlushing = true
let job
if (__DEV__) {
seen = seen || new Map()
}
while ((job = queue.shift())) {
if (__DEV__) {
checkRecursiveUpdates(seen!, job)
}
callWithErrorHandling(job, null, ErrorCodes.SCHEDULER)
}
flushPostFlushCbs(seen)
isFlushing = false
// some postFlushCb queued jobs!
// keep flushing until it drains.
if (queue.length || postFlushCbs.length) {
flushJobs(seen)
}
}
function checkRecursiveUpdates(seen: CountMap, fn: Function) {
if (!seen.has(fn)) {
seen.set(fn, 1)
} else {
const count = seen.get(fn)!
if (count > RECURSION_LIMIT) {
throw new Error(
'Maximum recursive updates exceeded. ' +
"You may have code that is mutating state in your component's " +
'render function or updated hook or watcher source function.'
)
} else {
seen.set(fn, count + 1)
}
}
}