state post get

src/state/mod.rs

@@ -1,7 +1,10 @@
 use super::*;
 use std::collections::{HashMap, HashSet};
 use std::sync::Arc;
-use tokio::sync::RwLock;
+use tokio::sync::{
+    RwLock,
+    RwLockReadGuard,
+};
 
 use user::{User, UserID};
 use post::Post;
@@ -16,6 +19,10 @@ struct Posts
     posts: HashMap<UserID, MaybeVec<RwLock<Post>>>,
 }
 
+/// A read lock over all posts and users
+#[derive(Debug)]
+pub struct PostsLock<'a>(RwLockReadGuard<'a, Posts>);
+
 #[derive(Debug)]
 struct Inner
 {
@@ -25,3 +32,50 @@ struct Inner
 /// Contains all posts and users
 #[derive(Debug, Clone)]
 pub struct State(Arc<Inner>);
+
+impl State
+{
+    /// Create a new empty state
+    pub fn new() -> Self
+    {
+	Self(Arc::new(
+	    Inner {
+		posts: RwLock::new(Posts {
+		    users: HashMap::new(),
+		    posts: HashMap::new(),
+		})
+	    }
+	))
+    }
+
+    /// Read lock over all posts and users
+    pub async fn posts(&self) -> PostsLock<'_>
+    {
+	PostsLock(self.0.posts.read().await)
+    }
+}
+
+impl<'a> PostsLock<'a>
+{
+    /// An iterator over all users in this state
+    pub fn users<'b>(&'b self) -> impl Iterator<Item = &'b RwLock<User>> + ExactSizeIterator + 'b
+    {
+	self.0.users.iter().map(|(_, u)| u)
+    }
+    
+    /// An iterator over all posts for this user
+    ///
+    /// # Notes
+    /// If this user does not exist, the returned iterator will yield 0 items.
+    pub fn posts_for<'b>(&'b self, user: &UserID) -> impl Iterator<Item= &'b RwLock<Post>> + ExactSizeIterator + 'b
+    where 'a: 'b
+    {
+	MaybeIter::from(self.0.posts.get(user).map(|x| x.iter()))
+    }
+    /// An iterator over all posts in the state
+    pub fn all_posts<'b>(&'b self) -> impl Iterator<Item= &'b RwLock<Post>> + 'b
+	where 'a: 'b
+    {
+	self.0.posts.iter().map(|(_, p)| p.iter()).flatten()
+    }
+}