mirrors
/
vt-social
mirror of https://github.com/nullptr-live/vt-social.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Fix possible duplicate statuses in timelines in some edge cases (#17971) 

In some rare cases, when receiving statuses out of order from the streaming
API then polling from the REST API, it was possible for the
`expandNormalizedTimeline` function to insert duplicates in the timeline,
which would then result in several bugs.

This commits ensures that there are no duplicates inserted in the
timeline.
main
Claire 2022-04-06 21:01:41 +02:00 committed by GitHub
parent 8f91e304a5
commit dd4c156f33
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 32 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
app/javascript/mastodon/reducers/timelines.js
View File

@ -16,7 +16,7 @@ import {
ACCOUNT_MUTE_SUCCESS,
ACCOUNT_UNFOLLOW_SUCCESS,
} from '../actions/accounts';
import { Map as ImmutableMap, List as ImmutableList, fromJS } from 'immutable';
import { Map as ImmutableMap, List as ImmutableList, OrderedSet as ImmutableOrderedSet, fromJS } from 'immutable';
import compareId from '../compare_id';
const initialState = ImmutableMap();
@ -32,6 +32,13 @@ const initialTimeline = ImmutableMap({
});
const expandNormalizedTimeline = (state, timeline, statuses, next, isPartial, isLoadingRecent, usePendingItems) => {
// This method is pretty tricky because:
// - existing items in the timeline might be out of order
// - the existing timeline may have gaps, most often explicitly noted with a `null` item
// - ideally, we don't want it to reorder existing items of the timeline
// - `statuses` may include items that are already included in the timeline
// - this function can be called either to fill in a gap, or load newer items
return state.update(timeline, initialTimeline, map => map.withMutations(mMap => {
mMap.set('isLoading', false);
mMap.set('isPartial', isPartial);
@ -46,15 +53,33 @@ const expandNormalizedTimeline = (state, timeline, statuses, next, isPartial, is
mMap.update(usePendingItems ? 'pendingItems' : 'items', ImmutableList(), oldIds => {
const newIds = statuses.map(status => status.get('id'));
const lastIndex = oldIds.findLastIndex(id => id !== null && compareId(id, newIds.last()) >= 0) + 1;
const firstIndex = oldIds.take(lastIndex).findLastIndex(id => id !== null && compareId(id, newIds.first()) > 0);
// Now this gets tricky, as we don't necessarily know for sure where the gap to fill is
// and some items in the timeline may not be properly ordered.
if (firstIndex < 0) {
return (isPartial ? newIds.unshift(null) : newIds).concat(oldIds.skip(lastIndex));
// However, we know that `newIds.last()` is the oldest item that was requested and that
// there is no “hole” between `newIds.last()` and `newIds.first()`.
// First, find the furthest (if properly sorted, oldest) item in the timeline that is
// newer than the oldest fetched one, as it's most likely that it delimits the gap.
// Start the gap *after* that item.
const lastIndex = oldIds.findLastIndex(id => id !== null && compareId(id, newIds.last()) >= 0) + 1;
// Then, try to find the furthest (if properly sorted, oldest) item in the timeline that
// is newer than the most recent fetched one, as it delimits a section comprised of only
// items present in `newIds` (or that were deleted from the server, so should be removed
// anyway).
// Stop the gap *after* that item.
const firstIndex = oldIds.take(lastIndex).findLastIndex(id => id !== null && compareId(id, newIds.first()) > 0) + 1;
// Make sure we aren't inserting duplicates
let insertedIds = ImmutableOrderedSet(newIds).subtract(oldIds.take(firstIndex), oldIds.skip(lastIndex)).toList();
// Finally, insert a gap marker if the data is marked as partial by the server
if (isPartial && (firstIndex === 0 || oldIds.get(firstIndex - 1) !== null)) {
insertedIds = insertedIds.unshift(null);
}
return oldIds.take(firstIndex + 1).concat(
isPartial && oldIds.get(firstIndex) !== null ? newIds.unshift(null) : newIds,
return oldIds.take(firstIndex).concat(
insertedIds,
oldIds.skip(lastIndex),
);
});