Add pastebin example.

Cargo.toml

@@ -27,4 +27,5 @@ members = [
   "examples/config",
   "examples/hello_alt_methods",
   "examples/raw_upload",
+  "examples/pastebin",
 ]

examples/pastebin/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "pastebin"
+version = "0.0.1"
+authors = ["Sergio Benitez <sb@sergio.bz>"]
+workspace = "../../"
+
+[dependencies]
+rocket = { path = "../../lib" }
+rocket_codegen = { path = "../../codegen" }
+rand = "0.3"

examples/pastebin/src/main.rs

@@ -0,0 +1,58 @@
+#![feature(plugin)]
+#![plugin(rocket_codegen)]
+
+extern crate rocket;
+extern crate rand;
+
+mod paste_id;
+
+use std::io;
+use std::fs::File;
+use std::path::Path;
+
+use rocket::Data;
+use rocket::response::{content, Failure};
+use rocket::http::StatusCode::NotFound;
+
+use paste_id::PasteID;
+
+const HOST: &'static str = "http://localhost:8000";
+const ID_LENGTH: usize = 3;
+
+#[post("/", data = "<paste>")]
+fn upload(paste: Data) -> io::Result<content::Plain<String>> {
+    let id = PasteID::new(ID_LENGTH);
+    let filename = format!("upload/{id}", id = id);
+    let url = format!("{host}/{id}\n", host = HOST, id = id);
+
+    paste.stream_to_file(Path::new(&filename))?;
+    Ok(content::Plain(url))
+}
+
+#[get("/<id>")]
+fn retrieve(id: PasteID) -> Result<content::Plain<File>, Failure> {
+    let filename = format!("upload/{id}", id = id);
+    File::open(&filename).map(|f| content::Plain(f)).map_err(|_| Failure(NotFound))
+}
+
+#[get("/")]
+fn index() -> &'static str {
+    "
+    USAGE
+
+      POST /
+
+          accepts raw data in the body of the request and responds with a URL of
+          a page containing the body's content
+
+          EXMAPLE: curl --data-binary @file.txt http://localhost:8000
+
+      GET /<id>
+
+          retrieves the content for the paste with id `<id>`
+    "
+}
+
+fn main() {
+    rocket::ignite().mount("/", routes![index, upload, retrieve]).launch()
+}

examples/pastebin/src/paste_id.rs

@@ -0,0 +1,47 @@
+use std::fmt;
+use std::borrow::Cow;
+
+use rocket::request::FromParam;
+use rand::{self, Rng};
+
+const BASE62: &'static [u8] = b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
+fn valid_id(id: &str) -> bool {
+    id.chars().all(|c| {
+        (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9')
+    })
+}
+
+pub struct PasteID<'a>(Cow<'a, str>);
+
+impl<'a> PasteID<'a> {
+    /// Here's how this works: get `size` random 8-bit integers, convert them
+    /// into base-62 characters, and concat them to get the ID.
+    pub fn new(size: usize) -> PasteID<'static> {
+        let mut id = String::with_capacity(size);
+        let mut rng = rand::thread_rng();
+        for _ in 0..size {
+            id.push(BASE62[rng.gen::<usize>() % 62] as char);
+        }
+
+        PasteID(Cow::Owned(id))
+    }
+}
+
+impl<'a> FromParam<'a> for PasteID<'a> {
+    type Error = &'a str;
+
+    fn from_param(param: &'a str) -> Result<PasteID<'a>, &'a str> {
+        match valid_id(param) {
+            true => Ok(PasteID(Cow::Borrowed(param))),
+            false => Err(param)
+        }
+    }
+}
+
+impl<'a> fmt::Display for PasteID<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+