import { avalon, config } from '../seed/core'
avalon.pendingActions = []
avalon.uniqActions = {}
avalon.inTransaction = 0
config.trackDeps = false
avalon.track = function() {
Iif (config.trackDeps) {
avalon.log.apply(avalon, arguments)
}
}
/**
* Batch is a pseudotransaction, just for purposes of memoizing ComputedValues when nothing else does.
* During a batch `onBecomeUnobserved` will be called at most once per observable.
* Avoids unnecessary recalculations.
*/
export function runActions() {
if (avalon.isRunningActions === true || avalon.inTransaction > 0)
return
avalon.isRunningActions = true
var tasks = avalon.pendingActions.splice(0, avalon.pendingActions.length)
for (var i = 0, task; task = tasks[i++];) {
task.update()
delete avalon.uniqActions[task.uuid]
}
avalon.isRunningActions = false
}
export function propagateChanged(target) {
var list = target.observers
for (var i = 0, el; el = list[i++];) {
el.schedule(); //通知action, computed做它们该做的事
}
}
//将自己抛到市场上卖
export function reportObserved(target) {
var action = avalon.trackingAction || null
if (action !== null) {
avalon.track('征收到', target.expr)
action.mapIDs[target.uuid] = target;
}
}
var targetStack = []
export function collectDeps(action, getter) {
if (!action.observers)
return
var preAction = avalon.trackingAction
Iif (preAction) {
targetStack.push(preAction)
}
avalon.trackingAction = action
avalon.track('【action】', action.type, action.expr, '开始征收依赖项')
//多个observe持有同一个action
action.mapIDs = {} //重新收集依赖
var hasError = true,
result
try {
result = getter.call(action)
hasError = false
} finally {
Iif (hasError) {
avalon.warn('collectDeps fail', getter + '')
action.mapIDs = {}
avalon.trackingAction = preAction
} else {
// 确保它总是为null
avalon.trackingAction = targetStack.pop()
try {
resetDeps(action)
} catch (e) {
avalon.warn(e)
}
}
return result
}
}
function resetDeps(action) {
var prev = action.observers,
curr = [],
checked = {},
ids = []
for (let i in action.mapIDs) {
let dep = action.mapIDs[i]
Eif (!dep.isAction) {
Iif (!dep.observers) { //如果它已经被销毁
delete action.mapIDs[i]
continue
}
ids.push(dep.uuid)
curr.push(dep)
checked[dep.uuid] = 1
if (dep.lastAccessedBy === action.uuid) {
continue
}
dep.lastAccessedBy = action.uuid
avalon.Array.ensure(dep.observers, action)
}
}
var ids = ids.sort().join(',')
if (ids === action.ids) {
return
}
action.ids = ids
if (!action.isComputed) {
action.observers = curr
} else {
action.depsCount = curr.length
action.deps = avalon.mix({}, action.mapIDs)
action.depsVersion = {};
for (let i in action.mapIDs) {
let dep = action.mapIDs[i]
action.depsVersion[dep.uuid] = dep.version
}
}
for (let i = 0, dep; dep = prev[i++];) {
if (!checked[dep.uuid]) {
avalon.Array.remove(dep.observers, action)
}
}
}
function transaction(action, thisArg, args) {
args = args || []
var name = 'transaction ' + (action.name || action.displayName || 'noop')
transactionStart(name)
var res = action.apply(thisArg, args)
transactionEnd(name)
return res
}
avalon.transaction = transaction
export function transactionStart(name) {
avalon.inTransaction += 1;
}
export function transactionEnd(name) {
if (--avalon.inTransaction === 0) {
avalon.isRunningActions = false
runActions()
}
} |