add r2d2 example

examples/r2d2/src/db.rs

@@ -0,0 +1,41 @@
+//! Db executor actor
+use std::io;
+use uuid;
+use actix_web::*;
+use actix::prelude::*;
+use r2d2::Pool;
+use r2d2_sqlite::SqliteConnectionManager;
+
+
+/// This is db executor actor. We are going to run 3 of them in parallel.
+pub struct DbExecutor(pub Pool<SqliteConnectionManager>);
+
+/// This is only message that this actor can handle, but it is easy to extend number of
+/// messages.
+pub struct CreateUser {
+    pub name: String,
+}
+
+impl Message for CreateUser {
+    type Result = Result<String, io::Error>;
+}
+
+impl Actor for DbExecutor {
+    type Context = SyncContext<Self>;
+}
+
+impl Handler<CreateUser> for DbExecutor {
+    type Result = Result<String, io::Error>;
+
+    fn handle(&mut self, msg: CreateUser, _: &mut Self::Context) -> Self::Result {
+        let conn = self.0.get().unwrap();
+
+        let uuid = format!("{}", uuid::Uuid::new_v4());
+        conn.execute("INSERT INTO users (id, name) VALUES ($1, $2)",
+                     &[&uuid, &msg.name]).unwrap();
+
+        Ok(conn.query_row("SELECT name FROM users WHERE id=$1", &[&uuid], |row| {
+            row.get(0)
+        }).map_err(|_| io::Error::new(io::ErrorKind::Other, "db error"))?)
+    }
+}

examples/r2d2/src/main.rs

@@ -0,0 +1,63 @@
+//! Actix web r2d2 example
+extern crate serde;
+extern crate serde_json;
+extern crate uuid;
+extern crate futures;
+extern crate actix;
+extern crate actix_web;
+extern crate env_logger;
+extern crate r2d2;
+extern crate r2d2_sqlite;
+extern crate rusqlite;
+
+use actix::*;
+use actix_web::*;
+use futures::future::Future;
+use r2d2_sqlite::SqliteConnectionManager;
+
+mod db;
+use db::{CreateUser, DbExecutor};
+
+
+/// State with DbExecutor address
+struct State {
+    db: Addr<Syn, DbExecutor>,
+}
+
+/// Async request handler
+fn index(req: HttpRequest<State>) -> Box<Future<Item=HttpResponse, Error=Error>> {
+    let name = &req.match_info()["name"];
+
+    req.state().db.send(CreateUser{name: name.to_owned()})
+        .from_err()
+        .and_then(|res| {
+            match res {
+                Ok(user) => Ok(httpcodes::HTTPOk.build().json(user)?),
+                Err(_) => Ok(httpcodes::HTTPInternalServerError.into())
+            }
+        })
+        .responder()
+}
+
+fn main() {
+    ::std::env::set_var("RUST_LOG", "actix_web=debug");
+    let _ = env_logger::init();
+    let sys = actix::System::new("r2d2-example");
+
+    let manager = SqliteConnectionManager::file("test.db");
+    let pool = r2d2::Pool::new(manager).unwrap();
+
+    // Start db executor actors
+    let addr = SyncArbiter::start(3, move || DbExecutor(pool.clone()));
+
+    // Start http server
+    let _addr = HttpServer::new(move || {
+        Application::with_state(State{db: addr.clone()})
+            // enable logger
+            .middleware(middleware::Logger::default())
+            .resource("/{name}", |r| r.method(Method::GET).a(index))})
+        .bind("127.0.0.1:8080").unwrap()
+        .start();
+
+    let _ = sys.run();
+}