sabi

Trait DataAcc

Source 
pub trait DataAcc {
    // Required method
    fn get_data_conn<C: DataConn + 'static>(
        &mut self,
        name: &str,
    ) -> Result<&mut C, Err>;
}
Expand description

The trait that aggregates data access operations to external data services into logical units, with methods providing default implementations.

The organization of these units is flexible; it can be per data service, per functional area, or any other meaningful grouping. Implementations of this trait use the get_data_conn method to obtain a DataConn object by the name specified during data source registration (via the global uses function or DataHub::uses method). This DataConn then facilitates data access operations to the associated data service.

Methods declared in DataAcc traits can be overridden by Data traits which will be passed to logic functions as their arguments using the override_macro crate. This design allows for the separation of data input/output logic into specific DataAcc implementations, while DataHub aggregates all these methods. Logic functions, however, only see the methods declared in the Data trait, enabling a clear separation and aggregation of data input/output methods.

Required Methods§

Source

fn get_data_conn<C: DataConn + 'static>( &mut self, name: &str, ) -> Result<&mut C, Err>

Retrieves a mutable reference to a DataConn object associated with the given name.

This method is used in default method implementations of DataAcc to obtain connections to specific external data services to perform data access operations.

§Parameters
  • name: The name of the data source, as registered with uses (global or DataHub’s method).
§Returns
  • Result<&mut C, Err>: A mutable reference to the DataConn if found and castable to the requested type C, or an Err if the data source is not found, or the DataConn cannot be cast to the specified type.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§