Method reduce_expression

src/sql/src/plan.rs:1600–1631

Attempt to reduce the internal [`MirScalarExpr`] into a simpler expression. The reduction happens on a separate thread, we also only wait for `WebhookValidation::MAX_REDUCE_TIME` before timing out and returning an error.

(&mut self)

    /// The reduction happens on a separate thread, we also only wait for
    /// `WebhookValidation::MAX_REDUCE_TIME` before timing out and returning an error.
    pub async fn reduce_expression(&mut self) -> Result<(), &'static str> {
        let WebhookValidation {
            expression,
            relation_desc,
            ..
        } = self;

        // On a different thread, attempt to reduce the expression.
        let mut expression_ = expression.clone();
        let desc_ = relation_desc.clone();
        let reduce_task = mz_ore::task::spawn_blocking(
            || "webhook-validation-reduce",
            move || {
                let repr_col_types: Vec<ReprColumnType> = desc_
                    .typ()
                    .column_types
                    .iter()
                    .map(ReprColumnType::from)
                    .collect();
                expression_.reduce(&repr_col_types);
                expression_
            },
        );

        match tokio::time::timeout(Self::MAX_REDUCE_TIME, reduce_task).await {
            Ok(reduced_expr) => {
                *expression = reduced_expr;
                Ok(())
            }
            Err(_) => Err("timeout"),
        }
    }
}

#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize)]