Struct StateTx 

pub struct StateTx<'a, T> { /* private fields */ }

A capability created only after an immediate write transaction starts.

Keep network requests and callbacks outside this capability. A group is loaded for one synchronous operation and is dropped before the transaction ends. A retry must enter a new transaction and load the group again.

Implementations

impl<T> StateTx<'_, T>

where T: TransactionalKeyStore,

pub fn with_group<R, E>( &mut self, group_id: GroupId, operation: impl FnOnce(&mut MlsGroup, &<T as TransactionalKeyStore>::Store<'_>) -> Result<R, E>, ) -> Result<R, E>

where E: From<StorageError> + From<SqlKeyStoreError>,

Load current state after the database writer has been acquired.

The operation borrows the group. It cannot return the mutable group or a future that borrows it. All storage access uses this transaction.

pub fn storage(&mut self) -> <T as TransactionalKeyStore>::Store<'_>

Access keys and records for a state operation that does not load a group.

pub fn savepoint<R, E>( &mut self, operation: impl FnOnce(&mut StateTx<'_, <<T as TransactionalKeyStore>::Store<'_> as XmtpMlsStorageProvider>::TxQuery>) -> Result<TransactionOutcome<R>, E>, ) -> Result<TransactionOutcome<R>, E>

where E: From<Error> + From<ConnectionError> + Error,

Roll back a failed attempt while retaining the outer writer lock.

The failed attempt’s group is dropped before the caller can load state to record a rejection. This also discards OpenMLS ratchet caches.