update functions

* introduce async handling
* use r2d2 as connection handler

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>

src/functions/config.rs

@@ -1,18 +1,21 @@
 /*
  * advotracker - Hotline tackingtool for Advocats
  *
- * Copyright 2019 Ralf Zerres <ralf.zerres@networkx.de>
+ * Copyright 2021 Ralf Zerres <ralf.zerres@networkx.de>
  * SPDX-License-Identifier: (0BSD or MIT)
  */
 
 //use diesel::debug_query;
-use diesel::prelude::*;
+use diesel::{
+    prelude::*,
+    r2d2::{Builder, ConnectionManager, Pool},
+};
 use diesel::sqlite::SqliteConnection;
 use diesel::sqlite::Sqlite;
 use dotenv::dotenv;
 use std::env;
 
-/// establish a sqlite connection
+/// establish a  connection
 pub fn establish_connection() -> SqliteConnection {
     // load our .env file
     dotenv().ok();
@@ -22,7 +25,8 @@ pub fn establish_connection() -> SqliteConnection {
 
     // establish a new SQLite connection (taking the reference from database_url)
     SqliteConnection::establish(&database_url)
-        .unwrap_or_else(|_| panic!("Error connecting to {}", &database_url))
+        .unwrap_or_else(|_| panic!("Error connecting to {}", &database_url));
+
     /*
      * WIP: integrate tracing!
     trace!(
@@ -33,6 +37,31 @@ pub fn establish_connection() -> SqliteConnection {
      */
 }
 
+/// establish a connection to a db pool
+pub fn build() -> Result<Pool<M>, Error> {
+    // TODO: consume database_url
+    // precedence in decreasing order:
+    // 1: commandline
+    // 2: env
+    // 3: user_config
+    // 4: system_config
+
+    // load .env file
+    dotenv().ok();
+
+    let database_url = env::var("DATABASE_URL").expect("DATABASE_URL must be set");
+
+    // establish a new SQLite connection (taking the reference from database_url)
+    // SqliteConnection::establish(&database_url)
+    //     .unwrap_or_else(|_| panic!("Error connecting to {}", &database_url))
+
+    // establish a new connection
+    let manager = ConnectionManager::<SqliteConnection>::new(&database_url);
+    let pool = Pool::builder.build(manager)?;
+
+    Ok(pool)
+}
+
 /// show the sql query
 pub fn show_query<T>(query: &T)
 where

src/functions/mod.rs

@@ -5,9 +5,8 @@
  * SPDX-License-Identifier: (0BSD or MIT)
  */
 
-// table specific functions
-/// module handling database connections
-pub mod db_connection;
+/// module handling configuratio of database
+pub mod config;
 
 /// module handling harms
 pub mod harms;

src/functions/roles.rs

@@ -7,9 +7,14 @@
 
 //#[cfg(test)]
 
+use async_std::*;
+use async_diesel::*;
 use chrono::Local;
 use diesel::debug_query;
-use diesel::prelude::*;
+use diesel::{
+    prelude::*,
+    r2d2::Pool,
+};
 use diesel::sqlite::{Sqlite, SqliteConnection};
 use diesel::{QueryDsl, RunQueryDsl};
 use std::error::Error;
@@ -22,17 +27,17 @@ use crate::schema::roles::dsl::*;
 use crate::schema::roles::*;
 
 impl Role {
-    // implement CRUD-Functions for our trait
+    // implement CRUD-Functions
     // new-    -> Create
     // show-   -> Read
     // update- -> Update
     // delete- -> Delete
 
     /// create a new role record
-    pub fn new(
+    pub async fn new(
         param_role_name: &str,
         param_id_user_changed: i32,
-        connection: &SqliteConnection,
+        pool: &Pool,
     ) -> Result<(), Box<dyn Error>> {
         //let row = Self::get(param_role_name, param_user_id_changed, &connection);
         //if row.len() == 0 {
@@ -45,12 +50,8 @@ impl Role {
         };
         diesel::insert_into(roles::table)
             .values(struct_role)
-            .execute(connection)?;
-
-        Ok(())
-        //else {
-        //    Err(("row already exists!"))
-        //}
+            .execute_async(&pool)
+            .await?;
     }
 
     /*

src/functions/tests.rs

@@ -6,11 +6,12 @@
  */
 
 #[cfg(test)]
-use diesel::debug_query;
+use async_std::*;
+//use diesel::debug_query;
 use diesel::dsl::*;
 use diesel::prelude::*;
-#[cfg(test)]
-use diesel::sqlite::Sqlite;
+//#[cfg(test)]
+//use diesel::sqlite::Sqlite;
 #[cfg(test)]
 use diesel::sqlite::SqliteConnection;
 
@@ -34,10 +35,10 @@ fn examine_set_users_default_values() {
 }
 
 /// set user defaults
-pub fn set_roles_default_values(connection: &SqliteConnection) -> QueryResult<usize> {
+pub async fn set_roles_default_values(pool: &pool) -> QueryResult<usize> {
     use schema::roles::dsl::*;
 
-    insert_into(roles).default_values().execute(connection)
+    insert_into(roles).default_values().execute_async(&pool).await?;
 }
 
 #[test]