mixin _.pushAll

[spalger]

This simple mixin efficiently copies the elements of one array into another.

Why?

While testing a bug that we suspected was caused by massive mappings, I created a mapping with 60,000 fields that crashed Kibana. It didn't run out of memory, or become unresponsive, it exceeded the maximum call stack by doing:

arr.push.apply(arr, otherArray);

This takes advantage of the multiple argument syntax of array push to push all of the elements from one array into another. Unfortunately it requires that all of the array elements are passed as function arguments which fills up the stack when the otherArray contains too many items.

[trevan]

In Firefox nightly, the apply.push is fastest, then forEach, then the allocate/fill, and finally splice.

[w33ble]

Looks good to me. Was this case in segmented.js? I wanted to try testing it with larger objects.

[w33ble]

I ran this against 2 400k long arrays with deep objects full of random data, and while it took a really long time to run, it ran just fine. So, I'm merging this. 😋