element-hq / element-hq/element-ios

RRs loading freezes the UI

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#4,839 0 comments 0 reactions 0 assignees View on GitHub
performance X-Regression
Dominant language
Swift
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Description

Since 1.5.2 and the lazy loading of RRs, the UI can freeze.
It is mainly visible just before the grey spinner disappears (while we are processing the /sync response) but it can happen afterwards while using the app:

Those freezes are reported by the logs
```
⚠️ [MXFileStore] Loaded read receipts of room: !xxxmatrix.org in 170ms, in main thread
⚠️ [MXFileStore] Loaded read receipts of room: !yyy:matrix.org in 62ms, in main thread

Contributor guide

Open the contributing guide

Research direction

Start by tracing MXFileStore's read-receipt loading during /sync and observing the logged main-thread timings. Reproduce the freeze around spinner dismissal and during normal app use; done means read-receipt processing no longer blocks the UI.

Written by the indexing model from the issue text.

Assessment

Tech stack
swift
Domain
mobile-dev, performance
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

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