Restructure folders (#411)

database_interactions/r2d2/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "r2d2-example"
+version = "1.0.0"
+authors = ["Nikolay Kim <fafhrd91@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+actix-web = "3"
+
+env_logger = "0.8"
+uuid = { version = "0.8", features = ["v4"] }
+
+r2d2 = "0.8"
+r2d2_sqlite = "0.14"
+rusqlite = "0.21"

database_interactions/r2d2/src/main.rs

@@ -0,0 +1,53 @@
+//! Actix web r2d2 example
+use std::io;
+
+use actix_web::{middleware, web, App, Error, HttpResponse, HttpServer};
+use r2d2::Pool;
+use r2d2_sqlite::SqliteConnectionManager;
+
+/// Async request handler. Ddb pool is stored in application state.
+async fn index(
+    path: web::Path<String>,
+    db: web::Data<Pool<SqliteConnectionManager>>,
+) -> Result<HttpResponse, Error> {
+    // execute sync code in threadpool
+    let res = web::block(move || {
+        let conn = db.get().unwrap();
+
+        let uuid = format!("{}", uuid::Uuid::new_v4());
+        conn.execute(
+            "INSERT INTO users (id, name) VALUES ($1, $2)",
+            &[&uuid, &path.into_inner()],
+        )
+        .unwrap();
+
+        conn.query_row("SELECT name FROM users WHERE id=$1", &[&uuid], |row| {
+            row.get::<_, String>(0)
+        })
+    })
+    .await
+    .map(|user| HttpResponse::Ok().json(user))
+    .map_err(|_| HttpResponse::InternalServerError())?;
+    Ok(res)
+}
+
+#[actix_web::main]
+async fn main() -> io::Result<()> {
+    std::env::set_var("RUST_LOG", "actix_web=debug");
+    env_logger::init();
+
+    // r2d2 pool
+    let manager = SqliteConnectionManager::file("test.db");
+    let pool = r2d2::Pool::new(manager).unwrap();
+
+    // start http server
+    HttpServer::new(move || {
+        App::new()
+            .data(pool.clone()) // <- store db pool in app state
+            .wrap(middleware::Logger::default())
+            .route("/{name}", web::get().to(index))
+    })
+    .bind("127.0.0.1:8080")?
+    .run()
+    .await
+}