Prevent memoized values being used in dependency loops

This commit is contained in:
Stefan Zermatten
2015-06-29 09:41:01 +02:00
parent e0ce6275bf
commit 453d4365d3

View File

@@ -15,6 +15,7 @@ function CacheObject(func, address, args, cache, context){
var self = this;
self.currentValue = null;
self.dep = new Tracker.Dependency();
self.numRun = 0;
//spawn a new autorun that keeps the value up-to-date
Tracker.nonreactive(function() {
@@ -26,8 +27,22 @@ function CacheObject(func, address, args, cache, context){
delete cache[address];
return;
}
//if we haven't run this before this flush, reset the counter after the flush
if(self.numRun === 0){
Tracker.afterFlush(function(){
self.numRun = 0;
});
}
self.numRun++;
//call the expensive function
//even if we don't use its value, we need to track its dependencies
var newValue = func.apply(context, args);
//prevent dependency loops, the memoized function shouldn't re-run
//more than once per flush
if (self.numRun > 1){
newValue = NaN;
if(_.isNaN(self.currentValue)) return;
}
//if the value changed, store the new value
if (self.currentValue !== newValue){
self.currentValue = newValue;