[BE] Use single connections instead of a Pool

backend/src/controller/person/mod.rs

@@ -2,6 +2,7 @@ use log::{error, info};
 use reqwest::Client;
 use rocket::http::Status;
 use rocket::serde::json::Json;
+use sqlx::Connection;
 
 use crate::json_result::JsonResult;
 use crate::model::person::{PersonCreate, PersonLink};
@@ -11,7 +12,7 @@ use crate::{db, model::person::Person};
 
 #[get("/person/<dni>")]
 pub async fn get_by_dni(dni: i32) -> (Status, Json<JsonResult<Person>>) {
-    let db = match db().await {
+    let mut db = match db().await {
         Ok(db) => db,
         Err(reason) => {
             return (Status::InternalServerError, JsonResult::err(reason));

backend/src/controller/scans/mod.rs

@@ -12,7 +12,7 @@ use std::{
 // TODO: Move to ENV
 const SCAN_PATH: &str = "/srv/srv/shares/eegsac/ESCANEOS/";
 
-/// Represents the result of parsing a QR code, and look for an eegsac URL.
+/// Represents the result of parsing a QR code, and looking for an eegsac URL.
 ///
 /// When the frontend requests the list of files available for conversion, this
 /// is sent. It contains essentially a unix timestamp

backend/src/main.rs

@@ -1,8 +1,9 @@
 use cors::Cors;
 use once_cell::sync::OnceCell;
 use sqlx::mysql::MySqlPoolOptions;
-use sqlx::{MySql, Pool};
+use sqlx::{MySql, Pool, MySqlConnection};
 use std::env;
+use sqlx::Connection;
 
 #[macro_use]
 extern crate rocket;
@@ -14,32 +15,12 @@ mod online_classroom;
 
 pub mod json_result;
 
-static DB: OnceCell<Pool<MySql>> = OnceCell::new();
+/// Opens & returns a connection to the database
-
-/// Returns a global reference to the database pool
 ///
-/// If the database pool has not been initialized, this function will attempt to initialize it
+/// We don't use a connection pool because it often times out,
-/// up to 3 times
+/// we don't have a lot of traffic and reiniting the pool would
-///
+/// require to change a lot of code in multiple places.
-/// If the database pool fails to initialize, this function will panic.
+pub async fn db() -> Result<MySqlConnection, String> {
-pub async fn db() -> Result<&'static Pool<MySql>, String> {
-    let attempts = 3;
-
-    for _ in 0..attempts {
-        match DB.get() {
-            Some(db) => return Ok(db),
-            None => {
-                log::info!("DB not initialized, initializing from db()");
-                let _ = init_db().await;
-            }
-        }
-    }
-
-    log::error!("Failed to initialize DB after {} attempts", attempts);
-    Err("Failed to initialize DB".to_string())
-}
-
-pub async fn init_db() -> Result<(), String> {
     /*
        Init DB and set it as a global variable
     */
@@ -48,21 +29,12 @@ pub async fn init_db() -> Result<(), String> {
         Err(_) => return Err("env DATABASE_URL not found".to_string()),
     };
 
-    let pool = MySqlPoolOptions::new()
+    let conn = sqlx::MySqlConnection::connect(db_url.as_str()).await;
-        .max_connections(5)
-        .connect(db_url.as_str())
-        .await;
 
-    match pool {
+    match conn {
-        Ok(pool) => match DB.set(pool) {
+        Ok(connection) => Ok(connection),
-            Ok(_) => Ok(()),
+        Err(reason) => {
-            Err(_) => {
+            log::error!("Error connecting to DB: {}", reason);
-                log::error!("Failed to set DB global variable");
-                Err("Failed to set DB".to_string())
-            }
-        },
-        Err(e) => {
-            log::error!("Error connecting to DB: {}", e);
             Err("Error connecting to DB".to_string())
         }
     }
@@ -73,7 +45,7 @@ async fn rocket() -> _ {
     dotenvy::dotenv().expect("Failed to load .env file");
     env_logger::init();
 
-    init_db().await;
+    // init_db().await;
 
     /* Init Rocket */
     rocket::build().attach(Cors {}).mount(

backend/src/model/course.rs

@@ -28,14 +28,14 @@ pub struct Course {
 
 impl Course {
     pub async fn get_all() -> Result<Vec<Course>, String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => {
                 return Err(reason);
             }
         };
 
-        let results = sqlx::query!("SELECT * FROM course").fetch_all(db).await;
+        let results = sqlx::query!("SELECT * FROM course").fetch_all(&mut db).await;
 
         let results = match results {
             Ok(res) => res,
@@ -60,7 +60,7 @@ impl Course {
     }
 
     pub async fn get_course_name(course_id: i32) -> Result<String, String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => {
                 return Err(reason);
@@ -71,7 +71,7 @@ impl Course {
             "SELECT course_name FROM course WHERE course_id = ?",
             course_id
         )
-        .fetch_one(db)
+        .fetch_one(&mut db)
         .await;
 
         match res {

backend/src/model/custom_label.rs

@@ -9,7 +9,7 @@ pub struct CustomLabel {
 
 impl CustomLabel {
     pub async fn get_all() -> Result<Vec<CustomLabel>, String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(reason),
         };
@@ -20,7 +20,7 @@ impl CustomLabel {
             FROM custom_label
             "#,
         )
-        .fetch_all(db)
+        .fetch_all(&mut db)
         .await;
 
         match result {
@@ -33,7 +33,7 @@ impl CustomLabel {
     }
 
     pub async fn get_id_by_value(value: &String) -> Result<i32, String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(reason),
         };
@@ -42,7 +42,7 @@ impl CustomLabel {
             "SELECT custom_label_id FROM custom_label WHERE custom_label_value = ?",
             value
         )
-        .fetch_all(db)
+        .fetch_all(&mut db)
         .await;
 
         let result = match result {
@@ -63,7 +63,7 @@ impl CustomLabel {
     }
 
     pub async fn create(value: &String) -> Result<i32, String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(reason),
         };
@@ -72,7 +72,7 @@ impl CustomLabel {
             "INSERT INTO custom_label (custom_label_value) VALUES (?)",
             value
         )
-        .execute(db)
+        .execute(&mut db)
         .await;
 
         if let Err(err) = result {

backend/src/model/person.rs

@@ -34,13 +34,13 @@ pub struct Person {
 
 impl Person {
     pub async fn get_by_dni(dni: i32) -> Result<Person, DBError> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(DBError::Str(reason)),
         };
 
         let result = sqlx::query_as!(Person, "SELECT * FROM person WHERE person_dni = ?", dni)
-            .fetch_one(db)
+            .fetch_one(&mut db)
             .await;
 
         match result {
@@ -63,7 +63,7 @@ pub struct PersonCreate {
 
 impl PersonCreate {
     pub async fn create(&self) -> Result<(), String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(err) => return Err(err),
         };
@@ -75,7 +75,7 @@ impl PersonCreate {
             self.person_paternal_surname,
             self.person_maternal_surname,
         )
-            .execute(db)
+            .execute(&mut db)
             .await;
 
         match result {
@@ -98,7 +98,7 @@ pub struct PersonLink {
 impl PersonLink {
     /// Links a person to a user in the online classroom
     pub async fn insert(&self) -> Result<(), String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(reason),
         };
@@ -109,7 +109,7 @@ impl PersonLink {
             self.person_classroom_username,
             self.person_id,
         )
-        .execute(db)
+        .execute(&mut db)
         .await;
 
         match res {

backend/src/model/register.rs

@@ -32,7 +32,7 @@ pub struct RegisterCreate {
 impl RegisterCreate {
     /// Registers a new certificate
     pub async fn create(&self) -> Result<(), String> {
-        let db = match db().await {
+        let mut db = match db().await {
             Ok(db) => db,
             Err(reason) => return Err(reason),
         };
@@ -78,7 +78,7 @@ impl RegisterCreate {
             self.person_id,
             self.course_id
         )
-        .execute(db)
+        .execute(&mut db)
         .await;
 
         match result {
@@ -91,7 +91,7 @@ impl RegisterCreate {
     }
 
     async fn get_next_register_code(course_id: i32) -> Result<i32, String> {
-        let db = db().await?;
+        let mut db = db().await?;
 
         let course_name = Course::get_course_name(course_id).await?;
 
@@ -102,7 +102,7 @@ impl RegisterCreate {
                 WHERE register_course_id IN 
                 (SELECT course_id FROM course WHERE course_name LIKE 'Matpel%')",
             )
-            .fetch_one(db)
+            .fetch_one(&mut db)
             .await;
 
             match res {
@@ -121,7 +121,7 @@ impl RegisterCreate {
                 WHERE register_course_id=?",
                 course_id
             )
-            .fetch_one(db)
+            .fetch_one(&mut db)
             .await;
 
             match res {
@@ -165,14 +165,14 @@ pub struct Register {
 
 impl Register {
     pub async fn get_by_dni(dni: String) -> Result<Vec<Register>, String> {
-        let db = db().await?;
+        let mut db = db().await?;
 
         let res = sqlx::query!(
             "SELECT * FROM register 
                 WHERE register_person_id = (SELECT person_id FROM person WHERE person_dni = ?)",
             dni
         )
-        .fetch_all(db)
+        .fetch_all(&mut db)
         .await;
 
         let res = match res {
@@ -201,10 +201,10 @@ impl Register {
     }
 
     pub async fn delete(register_id: i32) -> Result<(), String> {
-        let db = db().await?;
+        let mut db = db().await?;
 
         let res = sqlx::query!("DELETE FROM register WHERE register_id = ?", register_id)
-            .execute(db)
+            .execute(&mut db)
             .await;
 
         match res {
@@ -220,7 +220,7 @@ impl Register {
         register_id_list: String,
         person_dni_list: String,
     ) -> Result<Vec<ScanData>, String> {
-        let db = db().await?;
+        let mut db = db().await?;
  
         let sql = format!(
             "
@@ -253,6 +253,7 @@ impl Register {
         let result = match db.fetch_all(sql.as_str()).await {
             Ok(res) => res,
             Err(err) => {
+                drop(sqlx::Error::PoolTimedOut);
                 log::error!("Error fetching course & person: {:?}", err);
                 return Err("Error fetching course & person".into());
             }

frontend/src/OnlineClassroom/ClassroomUserCreation.tsx

@@ -17,7 +17,7 @@ export function ClassroomUserCreation(props: {
     person: Person,
     onCreate: (classroom_id: number, classroom_username: string) => void,
 }) {
-    const [email, setEmail] = createSignal("yuli.palo.apaza@gmail.com");
+    const [email, setEmail] = createSignal("alumno@eegsac.com");
     const [username, setUsername] = createSignal("USERNAME");
     const {setError, status, setStatus} = useLoading();
     const [names, setNames] = createSignal(props.person.person_names);

rs-front/.gitignore

@@ -2,4 +2,5 @@ dist
 .directory
 target
 public/tailwind.css
+.vscode