Simplify notifier registration and collection replication #6513
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| @@ -48,9 +48,8 @@ struct ListChangeInfo { | |||
| }; | |||
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| struct TransactionChangeInfo { | |||
| std::vector<ListChangeInfo> lists; | |||
| std::vector<ListChangeInfo> collections; | |||
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Consider changing the type to be called "CollectionChangeInfo"
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Good call. I took a look at all of the places related to this which were using the word "list" and changed a bunch to "collection". The two remaining exceptions are ListNotifier, which runs into the problem that we already have something named CollectionNotifier (and more broadly the problem that SDKs consider Results a collection but core kinda doesn't), and the KVO stuff which on the core side could work with all collections, but is NSArray-specific in obj-c.
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Notifications treat all collection types identically, so non-sync replication doesn't need to emit different instructions for each collection type. Parsing the old instructions is still supported to avoid having to bump the lockfile version.
When the notification code was originally written, opening a new SharedGroup was a very expensive operation and it was important to minimize the number of them used. This lead to some complicated logic to handle multiple source versions for notifiers where the single SharedGroup was incrementally advanced between the versions. This is now all obsolete; newly registered notifiers hold their own Transaction and can just be advanced separately.
This was used by the global notifier and has been unused ever since that was deleted.
We don't actually need TransactReverser for anything other than KVO these days, and the KVO parser can trivially do the required reversing itself. Sending schema change notifications from a rolled back write transaction was actually just incorrect to begin with, but was harmless other than being suboptimal.
…e actually used now
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Notifications treat all collection types identically, so non-sync replication doesn't need to emit different instructions for each collection type. This eliminates some duplicated code. Parsing the old instructions is still supported to avoid having to bump the lockfile version.
When the notification code was originally written, opening a new SharedGroup was a very expensive operation and it was important to minimize the number of them used. This lead to some complicated logic to handle multiple source versions for notifiers where the single SharedGroup was incrementally advanced between the versions. This is now all obsolete; newly registered notifiers hold their own Transaction and can just be advanced separately.
TransactionChangeInfo::track_all was part of the global notifier and has been unused ever since that was deleted.
We don't actually need TransactReverser for anything other than KVO these days, and the KVO parser can trivially do the required reversing itself. Sending schema change notifications from a rolled back write transaction was actually just incorrect to begin with, but was harmless other than being suboptimal.