sentinel_driver/connection/
portal_impl.rs

1use super::Connection;
2use crate::error::Result;
3use crate::portal::{self, Portal};
4use crate::row::Row;
5use crate::types::ToSql;
6
7impl Connection {
8    /// Create a server-side portal (cursor) for incremental row fetching.
9    ///
10    /// Portals only work inside transactions. The portal borrows the
11    /// connection state, so no concurrent queries while a portal is open.
12    ///
13    /// # Example
14    ///
15    /// ```rust,no_run
16    /// # async fn example(conn: &mut sentinel_driver::Connection) -> sentinel_driver::Result<()> {
17    /// conn.begin().await?;
18    /// let portal = conn.bind_portal("SELECT * FROM big_table", &[]).await?;
19    /// let batch = conn.query_portal(&portal, 100).await?;
20    /// conn.close_portal(portal).await?;
21    /// conn.commit().await?;
22    /// # Ok(())
23    /// # }
24    /// ```
25    pub async fn bind_portal(
26        &mut self,
27        sql: &str,
28        params: &[&(dyn ToSql + Sync)],
29    ) -> Result<Portal> {
30        portal::create_portal(&mut self.conn, sql, params).await
31    }
32
33    /// Fetch up to `max_rows` rows from a portal.
34    ///
35    /// Returns an empty `Vec` when the cursor is exhausted.
36    /// Use `max_rows = 0` to fetch all remaining rows.
37    pub async fn query_portal(&mut self, portal: &Portal, max_rows: i32) -> Result<Vec<Row>> {
38        let mut portal_mut = Portal {
39            name: portal.name.clone(),
40            description: portal.description.clone(),
41            exhausted: portal.exhausted,
42        };
43        let rows = portal::fetch_portal(&mut self.conn, &mut portal_mut, max_rows).await?;
44        Ok(rows)
45    }
46
47    /// Close a portal on the server, freeing resources.
48    pub async fn close_portal(&mut self, portal: Portal) -> Result<()> {
49        portal::close_portal(&mut self.conn, portal).await
50    }
51}
sentinel_driver/connection/portal_impl.rs

sentinel_driver/connection/
portal_impl.rs
