如何在O（1）的redux / vuex存储中更新元素？

Question

How do you usually update an element(hash) in a list in the store (redux, vuex) in O(1)?

I need the order of the elements, it's important (I can add/remove elements from the list). I will update elements on each millisecond, so a lot of updates will be made.

My question is, it's very bad to save the index of the element as a property of the element? Or if the list has 500-1000 elements, it's ok to use .find by Id for example?

Answer 1

Normalize your store shape with two properties

• Map of id to entity

• List of ids in the required order.

  { byId : { "post1" : { id : "post1", author : "user1", body : "......", comments : ["comment1", "comment2"] }, "post2" : { id : "post2", author : "user2", body : "......", comments : ["comment3", "comment4", "comment5"] } }, allIds : ["post1", "post2"] }

With this structure, you can update a particular entity in O(1) complexity, and also retrieve the entities in the order of insertion by iterating allIds .

More information can be found here