arel 0.0.7

arel: a sql orm
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54

use std::future::Future;
use once_cell::sync::OnceCell;

// use sqlx::sqlite::{SqlitePool};
use sqlx::any::{AnyPool};

#[derive(Debug)]
pub struct DbState {
    #[allow(dead_code)]
    name: &'static str,
    pool: AnyPool
}

impl DbState {
    pub fn pool(&self) -> &AnyPool {
        &self.pool
    }
    // eg:
    // db_state.exec(async move |db_state: &DbState| {
    //     Ok(())
    // }).await?;
    // pub async fn exec<'a: 'b, 'b, Fut>(&'a self, f: impl FnOnce(&'b DbState) -> Fut) -> anyhow::Result<()>
    //     where Fut: Future<Output = anyhow::Result<()>> {
    //     f(&self).await?;
    //     Ok(())
    // }
}

pub static DB_STATE_CELL: OnceCell<DbState>  = OnceCell::new();
pub async fn get_or_init_db_state<Fut>(f: impl FnOnce() -> Fut) -> anyhow::Result<&'static DbState>
    where Fut: Future<Output = Result<AnyPool, sqlx::Error>>
{
    if DB_STATE_CELL.get().is_none() {
        let pool = f().await?;
        if let Err(_) = DB_STATE_CELL.set(DbState {
            name: "default",
            pool,
        }) {
            return Err(anyhow::anyhow!("Set DB_STATE_CELL Failed"));
        }
    }
    if let Some(db_state) = DB_STATE_CELL.get() {
        Ok(db_state)
    } else {
        Err(anyhow::anyhow!("Get DB_STATE_CELL Failed"))
    }
}
pub fn get_db_state() -> anyhow::Result<&'static DbState> {
    if let Some(db_state) = DB_STATE_CELL.get() {
        Ok(db_state)
    } else {
        Err(anyhow::anyhow!("No DB State"))
    }
}