Trait Trigger 

pub trait Trigger: Send + Sync {
    // Required methods
    fn name(&self) -> &str;
    fn put(
        &self,
        txn_id: Option<u64>,
        key: &[u8],
        old_data: Option<&[u8]>,
        new_data: &[u8],
    );
    fn delete(&self, txn_id: Option<u64>, key: &[u8], old_data: &[u8]);

    // Provided methods
    fn commit(&self, _txn_id: u64) { ... }
    fn abort(&self, _txn_id: u64) { ... }
    fn add_trigger(&self, _txn_id: Option<u64>) { ... }
    fn remove_trigger(&self, _txn_id: Option<u64>) { ... }
}

A user-supplied database / transaction trigger.

Register one or more triggers on a crate::DatabaseConfig; the engine fires the record-operation methods (put / delete) within the transaction after each change, and the transaction-lifecycle methods (commit / abort) when the transaction resolves.

JE com.sleepycat.je.trigger.Trigger + TransactionTrigger.

Required Methods

fn name(&self) -> &str

The trigger’s name. All triggers on one database must have unique names. JE Trigger.getName.

fn put( &self, txn_id: Option<u64>, key: &[u8], old_data: Option<&[u8]>, new_data: &[u8], )

The trigger method invoked after a successful put, i.e. one that actually modified the database.

For a new insert, old_data is None; for an update of an existing record, old_data is Some(previous). new_data is always present. Fired within the transaction, after the change is applied.

JE Trigger.put(Transaction, DatabaseEntry key, DatabaseEntry oldData, DatabaseEntry newData).

• txn_id — the transaction id, or None if non-transactional.
• key — the (non-null) primary key.
• old_data — the data before the change, or None if the record did not previously exist.
• new_data — the (non-null) data after the change.

fn delete(&self, txn_id: Option<u64>, key: &[u8], old_data: &[u8])

The trigger method invoked after a successful delete, i.e. one that actually removed a key/data pair. Fired within the transaction, after the change is applied.

JE Trigger.delete(Transaction, DatabaseEntry key, DatabaseEntry oldData).

• txn_id — the transaction id, or None if non-transactional.
• key — the (non-null) primary key.
• old_data — the (non-null) data that was associated with the deleted key.

Provided Methods

fn commit(&self, _txn_id: u64)

The trigger method invoked after the transaction that modified this trigger’s database has committed. Only invoked if the database was modified during the transaction. Default: no-op (JE: trigger does not implement TransactionTrigger).

JE TransactionTrigger.commit(Transaction).

fn abort(&self, _txn_id: u64)

The trigger method invoked after the transaction that modified this trigger’s database has aborted. Only invoked if the database was modified during the transaction. Default: no-op.

JE TransactionTrigger.abort(Transaction).

fn add_trigger(&self, _txn_id: Option<u64>)

Lifecycle hook invoked when the trigger is added to the database (the first trigger method invoked, exactly once). Default: no-op.

JE Trigger.addTrigger(Transaction).

fn remove_trigger(&self, _txn_id: Option<u64>)

Lifecycle hook invoked when the trigger is removed from the database (e.g. on close). Default: no-op.

JE Trigger.removeTrigger(Transaction).

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors