contact_list apdex: research and development cycle 1

[michaelkohn]

One week time-box to do all of the following 👇 (1-4) as many times as necessary to get to 0.94 for contact_list.

1. Research
2. Plan
3. Develop
4. Evaluate

If 0.94 not achieved in 1 week, we will evaluate at the end of the week if we want to allocate an additional 1 week time-box for more work.

[Benmuiruri]

I have reviewed the contactsComponent, searchService and the search library and these are the findings of my research.

contactsComponent

• For the most part, I did not find any outright inefficiencies. Therefore, I focused on looking for possible refactoring that might improve performance.
  1. We can mark ngOnInit as async to simplify the asynchronous operations, using await and improve error handling
  2. We can extract the subscription logic into a separate manageChangesSubscription method to separate subscription logic from initialization logic.

searchService

1. I did not find any possible improvements to make to improve performance.

search library

1. Stefan left a comment to consider rewriting to not support skip and limit because they might not be fast. An issue was created but closed without the code being refactored.
2. There are multiple and nested iterations in the getIntersection method. Refactoring the method to use a single pass approach to calculate the intersection might improve performance. Also using _.intersection() involves creating several temporary arrays and then comparing all elements across these arrays to find common elements, which can be inefficient.

[Benmuiruri]

Hi @michaelkohn

After further review of the getIntersection method the refactor would add more complexity to the search service without offering any significant consistent performance improvements.

Therefore for this research and development cycle 1:

• I refactored the ngOnInit method in contactsComponent which might have a tiny performance improvement but not significant.

I would suggest marking cycle 1 as done and opening cycle 2 which will include:

1. Seeing whether it is possible to avoid mapping twice in the search lib
2. Investigate how we query for contacts_by_last_visited (code) in the searchService and in the contactsComponent
3. How we calculate getLastVisitedDates
4. Conduct a performance comparison of fetching 50 contacts (default) and fetching feww35
5. Review the query method in the contacts-component

[michaelkohn]

Sounds good, thanks @Benmuiruri.