serwus 0.2.3

Helpers for building actix-web/diesel based services
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

use diesel::r2d2::ConnectionManager;
use log::{error, info};
use std::env;

use crate::threads::num_threads;

use super::DbConnection;

pub type Pool = diesel::r2d2::Pool<ConnectionManager<DbConnection>>;

/// Init pool of N connections to single database, where N is number of threads (but not less than 2).
///
/// Database URL is taken from `DATABASE` env variable.
/// If `TEST` env variable is defined then size is capped to 2.
pub fn init_default_pool() -> Result<Pool, r2d2::Error> {
    let nthreads = num_threads();
    init_pool(if nthreads > 1 { nthreads } else { 2 })
}

/// Init pool of `size` connections to single database
///
/// Database URL is taken from `DATABASE` env variable.
/// If `TEST` env variable is defined then size is capped to 2.
pub fn init_pool(size: usize) -> Result<Pool, r2d2::Error> {
    info!("Connecting to database");

    let manager = ConnectionManager::<DbConnection>::new(default_database_url());

    let max_size = if env::var("TEST").is_ok() && size > 2 {
        2
    } else {
        size
    };

    // #[allow(clippy::cast_possible_truncation)]
    Pool::builder()
        .max_size(max_size as u32)
        .build(manager)
        .map_err(|err| {
            error!("Can't connect to database: {err}");
            err
        })
}

pub(super) fn database_url(env_name: &str) -> String {
    env::var(env_name).unwrap_or_else(|_| format!("{env_name} must be set"))
}

fn default_database_url() -> String {
    database_url("DATABASE_URL")
}