WIP - Scroll performance fixes for when there are many read posts already #66
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mikedg1
commented
Nov 18, 2024
| @@ -61,9 +63,7 @@ struct SubredditFeedView: View { | |||
| ThemedList(appTheme: appTheme, textSizePreference: textSizePreference, stripStyling: true) { | |||
| if !posts.isEmpty && searchTerm.isEmpty { | |||
| ForEach(posts, id: \.id) { post in | |||
| var isRead: Bool { | |||
| readPosts.contains(where: { $0.readPostId == post.id }) | |||
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This seemed to be the bottleneck.
mikedg1
commented
Nov 18, 2024
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| var newReadIds: Set<String> = [] | ||
| newPosts.forEach { post in | ||
| let isRead = readPosts.contains(where: { $0.readPostId == post.id }) |
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We do the "slow" check on load, off the main thread.
mikedg1
changed the title
|
Evaluating some alternatives to this that don't require a separate data structure. |
mikedg1
changed the title
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Evaluating some alternatives to this that don't require a separate data structure.
Description:
After adding the "mark read on scroll" feature, it seemed like scrolling performance took a hit. With some of my limited Instruments experience, it seemed like this was related to looking through the read posts FetchedResults to determine isRead when it gets to be several hundred items large. If I made the incorrect determination, then this PR is likely focused on a poor fix.
Altertnatives looked into: Adding an index. This didn't seem to help.
Changes:
Moved lookup to work off the main thread. This is at the expense of a slightly longer initial load for each page of content.
Removed an unused private function.
Keep track of read posts in memory for the current list.