Is it possible to create a “weak reference” in javascript?

Question

Is there any way in javascript to create a \"weak reference\" to another object? Here is the wiki page describing what a weak reference is. Here is another article that desc

Answer 1

True weak references, no, not yet (but browser makers are looking at the subject). But here is an idea on how to simulate weak references.

You could build a cache which you drive your objects through. When an object is stored, the cache keeps a prediction of how much memory the object will take up. For some items, like storing images, this is straight forward to work out. For others this would be more difficult.

When you need an object, you then ask the cache for it. If the cache has the object, it is returned. If it is not there, then the item is generated, stored, and then returned.

The weak references are simulated by the cache removing items, when the total amount of predicted memory reaches a certain level. It will predict which items are least used based on how often they are retrieved, weighted by how long ago they were taken out. A 'calculation' cost could also be added, if the code that creates the item is passed into the cache as a closure. This would allow the cache to keep items which are very expensive to build or generate.

The deletion algorithm is key, because if you get this wrong then you could end up removing the most popular items. This would cause terrible performance.

As long as the cache is the only object with permanent references to the objects stored, then the above system should work pretty well as an alternative to true weak references.