Extremely poor performance in certain cases

[nealoke]

Hi, I've come across an issue in my application where I use this project to batch around 160 actions at once, but for some reason it is causing my UI to freeze as it takes around 1.5s to dispatch it.

Things I checked as best as i can that are not causing the UI freezing:

• react-redux's connect() method on the components
• unwanted render()s of all components involved
• Tested the reducer with performance.now() and it takes exactly 0.0001s to run it (times 160 is 0.0160s)

Pseudo code

const actions = [
    {
        type: 'RECEIVE_ACCOUNT_DAY_STAT',
        payload: { ... }
    },

    // x 160
];

dispatch(actions); // This takes around 1.5s

[arcanis]

I don't see any reason why redux-batch would have such a perf impact by itself. It doesn't do anything crazy other than a map (or some recursion in case you have arrays within arrays, but that's probably quite rare) :/

[arcanis]

If you want to debug this on your side, dispatchRecurse is the only part of the code with a non-constant complexity. I suggest adding performance.now() calls here and see what happens.

[linonetwo]

I think the problem may be the cost of the UI rerender. I used to update a huge table, and in a single rerender, it freezes. Using immutable solves it.