Add minimal example, some formatting, bump parking_lot version

Cargo.toml

@@ -18,4 +18,4 @@ categories = [
 [dependencies]
 rand = "0.8"
 rocket = "0.5.0-rc.2"
-parking_lot = "0.11"
+parking_lot = "0.12"

README.md

@@ -13,6 +13,8 @@ The implementation is generic to support any type as session data: a custom stru
 The session lifetime, cookie name, and other parameters can be configured by calling chained 
 methods on the fairing. When a session expires, the data associated with it is dropped.
 
+Example: `Session::fairing().with_lifetime(Duration::from_secs(15))`
+
 ## Usage
 
 To use session in a route, first make sure you have the fairing attached by calling
@@ -31,7 +33,7 @@ the session list does not waste memory.
 
 ## Examples
 
-(More examples are in the examples folder)
+More examples are in the "examples" folder - run with `cargo run --example=NAME`
 
 ### Basic Example
 
@@ -39,19 +41,16 @@ This simple example uses u64 as the session variable; note that it can be a stru
 it just needs to implement `Send + Sync + Default`. 
 
 ```rust
-#![feature(proc_macro_hygiene, decl_macro)]
-#[macro_use] extern crate rocket;
-
-use std::time::Duration;
+#[macro_use]
+extern crate rocket;
 
-// It's convenient to define a type alias:
-pub type Session<'a> = rocket_session::Session<'a, u64>;
+type Session<'a> = rocket_session::Session<'a, u64>;
 
-fn main() {
-    rocket::ignite()
+#[launch]
+fn rocket() -> _ {
+    rocket::build()
         .attach(Session::fairing())
         .mount("/", routes![index])
-        .launch();
 }
 
 #[get("/")]
@@ -67,6 +66,7 @@ fn index(session: Session) -> String {
 
     format!("{} visits", count)
 }
+
 ```
 
 ## Extending Session by a Trait
@@ -76,8 +76,8 @@ The `.tap()` method is powerful, but sometimes you may wish for something more c
 Here is an example of using a custom trait and the `json_dotpath` crate to implement
 a polymorphic store based on serde serialization. 
 
-Note that this approach is prone to data races, since every method contains its own `.tap()`.
-It may be safer to simply call the `.dot_*()` methods manually in one shared closure.
+Note that this approach is prone to data races if you're accessing the session object multiple times per request, 
+since every method contains its own `.tap()`. It may be safer to simply call the `.dot_*()` methods manually in one shared closure.
 
 ```rust
 use serde_json::Value;

examples/minimal/main.rs

@@ -0,0 +1,28 @@
+#[macro_use]
+extern crate rocket;
+
+use std::time::Duration;
+
+type Session<'a> = rocket_session::Session<'a, u64>;
+
+#[launch]
+fn rocket() -> _ {
+    // This session expires in 15 seconds as a demonstration of session configuration
+    rocket::build()
+        .attach(Session::fairing().with_lifetime(Duration::from_secs(15)))
+        .mount("/", routes![index])
+}
+
+#[get("/")]
+fn index(session: Session) -> String {
+    let count = session.tap(|n| {
+        // Change the stored value (it is &mut)
+        *n += 1;
+
+        // Return something to the caller.
+        // This can be any type, 'tap' is generic.
+        *n
+    });
+
+    format!("{} visits", count)
+}

src/lib.rs

@@ -1,6 +1,12 @@
+use std::borrow::Cow;
+use std::collections::HashMap;
+use std::fmt::{self, Display, Formatter};
+use std::marker::PhantomData;
+use std::ops::Add;
+use std::time::{Duration, Instant};
+
 use parking_lot::{Mutex, RwLock, RwLockUpgradableReadGuard};
 use rand::{rngs::OsRng, Rng};
-
 use rocket::{
     fairing::{self, Fairing, Info},
     http::{Cookie, Status},
@@ -9,13 +15,6 @@ use rocket::{
     Build, Request, Response, Rocket, State,
 };
 
-use std::borrow::Cow;
-use std::collections::HashMap;
-use std::fmt::{self, Display, Formatter};
-use std::marker::PhantomData;
-use std::ops::Add;
-use std::time::{Duration, Instant};
-
 /// Session store (shared state)
 #[derive(Debug)]
 pub struct SessionStore<D>
@@ -134,11 +133,10 @@ where
                 let store_ug = store.inner.upgradable_read();
 
                 // Resolve session ID
-                let id = if let Some(cookie) = request.cookies().get(&store.config.cookie_name) {
-                    Some(SessionID(cookie.value().to_string()))
-                } else {
-                    None
-                };
+                let id = request
+                    .cookies()
+                    .get(&store.config.cookie_name)
+                    .map(|cookie| SessionID(cookie.value().to_string()));
 
                 let expires = Instant::now().add(store.config.lifespan);
 
@@ -200,7 +198,7 @@ where
                     new_id
                 }
             }),
-            store: store,
+            store,
         })
     }
 }