Trait Engine 

pub trait Engine:
    WithEventBus
    + Send
    + Sync
    + Clone
    + 'static {
    type Command: CommandTransaction;
    type Query: QueryTransaction;

    // Required methods
    fn begin_command<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = Result<Self::Command>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
    fn begin_query<'life0, 'async_trait>(
        &'life0 self,
    ) -> Pin<Box<dyn Future<Output = Result<Self::Query>> + Send + 'async_trait>>
       where Self: 'async_trait,
             'life0: 'async_trait;
    fn command_as(
        &self,
        identity: &Identity,
        rql: &str,
        params: Params,
    ) -> SendableFrameStream;
    fn query_as(
        &self,
        identity: &Identity,
        rql: &str,
        params: Params,
    ) -> SendableFrameStream;
}

Async database engine trait.

This trait defines the core interface for database engines. The command_as and query_as methods return async streams for non-blocking execution.

All methods create Send futures to work with tokio’s multi-threaded runtime.

Required Associated Types

type Command: CommandTransaction

type Query: QueryTransaction

Required Methods

fn begin_command<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Self::Command>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Begin a new command (write) transaction.

fn begin_query<'life0, 'async_trait>( &'life0 self, ) -> Pin<Box<dyn Future<Output = Result<Self::Query>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

Begin a new query (read) transaction.

fn command_as( &self, identity: &Identity, rql: &str, params: Params, ) -> SendableFrameStream

Execute a command and return a stream of result frames.

Commands are write operations (INSERT, UPDATE, DELETE, DDL) that modify the database state. The command runs in a transaction that is automatically committed on success or rolled back on error.

fn query_as( &self, identity: &Identity, rql: &str, params: Params, ) -> SendableFrameStream

Execute a query and return a stream of result frames.

Queries are read operations (SELECT) that do not modify the database. Results are streamed as they become available, providing backpressure if the consumer is slow.

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