Move business logic out of main, use askama and bound the ENTRIES

src/io.rs

@@ -0,0 +1,45 @@
+extern crate gpw;
+extern crate linked_hash_map;
+
+use linked_hash_map::LinkedHashMap;
+
+use std::sync::RwLock;
+use std::env;
+use std::cell::RefCell;
+
+lazy_static! {
+    static ref ENTRIES: RwLock<LinkedHashMap<String, String>> = RwLock::new(LinkedHashMap::new());
+}
+
+/// Ensures `ENTRIES` is less than the size of `BIN_BUFFER_SIZE`. If it isn't then
+/// `ENTRIES.len() - BIN_BUFFER_SIZE` elements will be popped off the front of the map.
+fn purge_old() {
+    let entries_len = ENTRIES.read().unwrap().len();
+    let buffer_size = env::var("BIN_BUFFER_SIZE").map(|f| f.parse::<usize>().unwrap()).unwrap_or(1000usize);
+
+    if entries_len > buffer_size {
+        let to_remove = entries_len - buffer_size;
+
+        let mut entries = ENTRIES.write().unwrap();
+
+        for _ in 0..to_remove {
+            entries.pop_front();
+        }
+    }
+}
+
+/// Generates a randomly generated id, stores the given paste under that id and then returns the id.
+pub fn store_paste(content: String) -> String {
+    thread_local!(static KEYGEN: RefCell<gpw::PasswordGenerator> = RefCell::new(gpw::PasswordGenerator::default()));
+    let id = KEYGEN.with(|k| k.borrow_mut().next().unwrap());
+
+    purge_old();
+    ENTRIES.write().unwrap().insert(id.clone(), content);
+
+    id
+}
+
+/// Get a paste by id. Returns `None` if the paste doesn't exist.
+pub fn get_paste<'a>(id: &str) -> Option<String> {
+    ENTRIES.read().unwrap().get(id).map(|f| f.clone())
+}