veloren/server/src/persistence/mod.rs

pub mod character;
mod models;

mod schema;

extern crate diesel;

use diesel::prelude::*;
use diesel_migrations::embed_migrations;
use std::{env, fmt, fs, path::Path};

#[derive(Debug)]
pub enum Error {
    // The player has alredy reached the max character limit
    CharacterLimitReached,
    // An error occured when performing a database action
    DatabaseError(diesel::result::Error),
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", match self {
            Self::DatabaseError(diesel_error) => diesel_error.to_string(),
            Self::CharacterLimitReached => String::from("Character limit exceeded"),
        })
    }
}

impl From<diesel::result::Error> for Error {
    fn from(error: diesel::result::Error) -> Error { Error::DatabaseError(error) }
}

// See: https://docs.rs/diesel_migrations/1.4.0/diesel_migrations/macro.embed_migrations.html
// This macro is called at build-time, and produces the necessary migration info
// for the `embedded_migrations` call below.
embed_migrations!();

pub fn run_migrations() -> Result<(), diesel_migrations::RunMigrationsError> {
    let _ = fs::create_dir(format!("{}/saves/", binary_absolute_path()));
    embedded_migrations::run_with_output(&establish_connection(), &mut std::io::stdout())
}

fn establish_connection() -> SqliteConnection {
    let database_url = format!("{}/saves/db.sqlite", binary_absolute_path());
    SqliteConnection::establish(&database_url)
        .unwrap_or_else(|_| panic!("Error connecting to {}", database_url))
}

// Get the absolute path of the binary so that the database is always stored
// beside it, no matter where the binary is run from
fn binary_absolute_path() -> String {
    let binary_path;
    match env::current_exe() {
        Ok(exe_path) => binary_path = exe_path,
        Err(e) => panic!("Failed to get current exe path: {}", e),
    };

    match Path::new(&binary_path.display().to_string()).parent() {
        Some(path) => return path.display().to_string(),
        None => panic!("Failed to get current exe parent path"),
    };
}