Expand description

Asynchronous handle for rusqlite library.

Guide

This library provides Connection struct. Connection struct is a handle to call functions in background thread and can be cloned cheaply. Connection::call method calls provided function in the background thread and returns its result asynchronously.

Design

A thread is spawned for each opened connection handle. When call method is called: provided function is boxed, sent to the thread through mpsc channel and executed. Return value is then sent by oneshot channel from the thread and then returned from function.

Example

use rusqlite::{params, Result};
use tokio_rusqlite::Connection;

#[derive(Debug)]
struct Person {
    id: i32,
    name: String,
    data: Option<Vec<u8>>,
}

#[tokio::main]
async fn main() -> Result<()> {
    let conn = Connection::open_in_memory().await?;

    let people = conn
        .call(|conn| {
            conn.execute(
                "CREATE TABLE person (
                    id    INTEGER PRIMARY KEY,
                    name  TEXT NOT NULL,
                    data  BLOB
                )",
                [],
            )?;

            let steven = Person {
                id: 1,
                name: "Steven".to_string(),
                data: None,
            };

            conn.execute(
                "INSERT INTO person (name, data) VALUES (?1, ?2)",
                params![steven.name, steven.data],
            )?;

            let mut stmt = conn.prepare("SELECT id, name, data FROM person")?;
            let people = stmt
                .query_map([], |row| {
                    Ok(Person {
                        id: row.get(0)?,
                        name: row.get(1)?,
                        data: row.get(2)?,
                    })
                })?
                .collect::<Result<Vec<Person>, rusqlite::Error>>()?;

            Ok::<_, rusqlite::Error>(people)
        })
        .await?;

    for person in people {
        println!("Found person {:?}", person);
    }

    Ok(())
}

Structs

A handle to call functions in background thread.