We still need the AxolotlKit model classes to migrate old sessions,
but we don't need any of the actual protocol support. This also
means we can drop HKDFKit.
Additionally, we do still use some utilities from AxolotlKit:
- AxolotlExceptions.h: NSException names, should eventually be
replaced by NSErrors everywhere
- NSData+keyVersionByte.h: prepend/remove public key type byte,
should eventually be replaced by strong types (ECPublicKey)
- SPKProtocolContext.h: defines the SPKProtocol{Read,Write}Context
marker protocols, should be replaced by direct use of
SDSAny{Read,Write}Transaction
OWSAccountIdFinder is no longer used for dependency injection in
SignalMetadataKit, so there's no need to allocate empty NSObjects just
to call the methods.
No functionality change.
The generic observer delete was broken for GRDB, because we can't fetch the
uniqueId's of rowIds if the corresponding row was deleted. So instead, we
split the logic: Yap uses uniqueIds, GRDB uses row ids.
UIDatabaseObserver orchestrates notifying views when a transaction commits.
We back UIDatabaseObserver with a DatabaseRegionObserver
DatabaseRegionObservers are not notified if the transaction contains no changes:
https://github.com/groue/GRDB.swift/blob/af0ac15/GRDB/Core/DatabaseRegionObservation.swift#L119
However the more general TransactionObservers *are* notified even if the
transaction contains no changes. Nicely, GRDB does some work to ensure this is
true even in the event of a deferred transaction. See this comment on `databaseDidCommitEmptyDeferredTransaction`
da459386a0/GRDB/Core/TransactionObserver.swift (L444)
