Trait ProcedurePlugin 

pub trait ProcedurePlugin: Send + Sync {
    // Required methods
    fn signature(&self) -> &ProcedureSignature;
    fn invoke(
        &self,
        ctx: ProcedureContext<'_>,
        args: &[ColumnarValue],
    ) -> Result<SendableRecordBatchStream, FnError>;
}

A Cypher procedure plugin — CALL uni.foo.bar(args) YIELD ....

Procedures return a stream of RecordBatches; the host attaches the stream to the surrounding query plan via a ProcedureCallExec node.

Required Methods

fn signature(&self) -> &ProcedureSignature

Static signature.

fn invoke( &self, ctx: ProcedureContext<'_>, args: &[ColumnarValue], ) -> Result<SendableRecordBatchStream, FnError>

Invoke the procedure with the given arguments and execution context.

The returned stream is consumed lazily by downstream YIELD. The procedure is responsible for cooperatively yielding to the executor (no long blocking calls; use tokio::task::yield_now between batches).

Errors

Returns FnError if the procedure cannot start (validation failure, capability check). Errors raised during stream production are signaled via Err items in the stream.

Dyn Compatibility

This trait is dyn compatible.

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

Implementors