[BE] Fixes #39: Spawn a connection on every request rather than having a db pool

backend/.gitignore

@@ -4,3 +4,4 @@ aulavirtual
 scraps
 request-logs
 .idea
+.directory

backend/src/controller/classroom/mod.rs

@@ -12,8 +12,8 @@ use rocket::{http::Status, serde::json::Json};
 
 mod courses;
 
-pub use courses::disenroll_user_options;
 pub use courses::disenroll_user;
+pub use courses::disenroll_user_options;
 
 #[options("/classroom/user")]
 pub fn create_user_options() -> Status {

backend/src/controller/person/mod.rs

@@ -4,6 +4,7 @@ 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};

backend/src/main.rs

@@ -1,7 +1,8 @@
 use cors::Cors;
 use once_cell::sync::OnceCell;
-use sqlx::mysql::MySqlPoolOptions;
+use sqlx::Connection;
 use sqlx::MySql;
+use sqlx::MySqlConnection;
 use sqlx::Pool;
 use std::env;
 use std::time::Instant;
@@ -20,13 +21,13 @@ static DB: OnceCell<Pool<MySql>> = OnceCell::new();
 
 /// Opens & returns a connection to the database
 ///
-/// We don't use a connection pool because it often times out,
+/// We don't use a connection pool because on some days, on the afternoon,
-/// we don't have a lot of traffic and reiniting the pool would
+/// the connections die and the user has to wait for all 5 connections
-/// require to change a lot of code in multiple places.
+/// in the pool to die and then wait for the new connections to be created.
-pub async fn db() -> Result<&'static Pool<MySql>, String> {
+pub async fn db() -> Result<MySqlConnection, String> {
     /*
        Init DB and set it as a global variable
-    * /
+    */
     let db_url = match env::var("DATABASE_URL") {
         Ok(url) => url,
         Err(_) => return Err("env DATABASE_URL not found".to_string()),
@@ -43,73 +44,6 @@ pub async fn db() -> Result<&'static Pool<MySql>, String> {
             Err("Error connecting to DB".to_string())
         }
     }
-    // */
-
-    let attempts = 3;
-
-    for _ in 0..attempts {
-        match DB.get() {
-            Some(db) => {
-                log::info!("DB active connections: {}", db.size());
-                log::info!("DB num_idle connections: {}", db.num_idle());
-
-                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
-    */
-    let db_url = match env::var("DATABASE_URL") {
-        Ok(url) => url,
-        Err(_) => return Err("env DATABASE_URL not found".to_string()),
-    };
-
-    let start = Instant::now();
-    let pool = MySqlPoolOptions::new()
-        .max_connections(5)
-        /*
-        On some afternoons for some god forsaken reason the idle connections
-        to the db stay alive, but stop responding.
-        When this happens, we must restart the server, or wait for all
-        the active connections to timeout.
-        Here are some measures to circumvent that:
-        */
-        // Set the maximum wait time for connections to 10 seconds
-        // In practice, the slowest connections take 1.5 seconds to connect
-        .acquire_timeout(std::time::Duration::from_secs(10))
-        // Set the maximum idle time for connections to 10 minutes
-        .idle_timeout(std::time::Duration::from_secs(10 * 60))
-        .connect(db_url.as_str())
-        .await;
-    log::info!(
-        "DB Pool connection took: {:?} ms",
-        start.elapsed().as_millis()
-    );
-
-    match pool {
-        Ok(pool) => match DB.set(pool) {
-            Ok(_) => Ok(()),
-            Err(_) => {
-                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())
-        }
-    }
 }
 
 #[launch]

backend/src/model/course.rs

@@ -35,7 +35,7 @@ impl Course {
             }
         };
 
-        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,
@@ -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

@@ -20,7 +20,7 @@ impl CustomLabel {
             FROM custom_label
             "#,
         )
-        .fetch_all(db)
+        .fetch_all(&mut db)
         .await;
 
         match result {
@@ -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 {
@@ -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

@@ -36,14 +36,14 @@ 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 start = Instant::now();
         let result = sqlx::query_as!(Person, "SELECT * FROM person WHERE person_dni = ?", dni)
-            .fetch_one(db)
+            .fetch_one(&mut db)
             .await;
         log::info!(
             "DB query (person by dni) took: {:?} ms",
@@ -82,7 +82,7 @@ impl PersonCreate {
             self.person_paternal_surname,
             self.person_maternal_surname,
         )
-            .execute(db)
+            .execute(&mut db)
             .await;
 
         match result {
@@ -116,7 +116,7 @@ impl PersonLink {
             self.person_classroom_username,
             self.person_id,
         )
-        .execute(db)
+        .execute(&mut db)
         .await;
 
         match res {

backend/src/model/register.rs

@@ -83,7 +83,7 @@ impl RegisterCreate {
             self.person_id,
             self.course_id
         )
-        .execute(db)
+        .execute(&mut db)
         .await;
 
         match result {
@@ -107,7 +107,7 @@ 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 {
@@ -126,7 +126,7 @@ impl RegisterCreate {
                 WHERE register_course_id=?",
                 course_id
             )
-            .fetch_one(db)
+            .fetch_one(&mut db)
             .await;
 
             match res {
@@ -345,7 +345,7 @@ impl Register {
                 WHERE register_person_id = (SELECT person_id FROM person WHERE person_dni = ?)",
             dni
         )
-        .fetch_all(db)
+        .fetch_all(&mut db)
         .await;
         log::info!(
             "DB (get register by id) took: {:?} ms",
@@ -381,7 +381,7 @@ impl Register {
         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 {

frontend/src/index.css

@@ -32,20 +32,22 @@ body {
 
 .progress {
     animation: progress 1s infinite linear;
-  }
+}
 
-  .left-right {
+.left-right {
     transform-origin: 0% 50%;
-  }
+}
-      @keyframes progress {
+
+@keyframes progress {
     0% {
         transform: translateX(0) scaleX(0);
     }
+
     40% {
         transform: translateX(0) scaleX(0.4);
     }
+
     100% {
         transform: translateX(100%) scaleX(0.5);
     }
-  }
+}
-