Query partial code

src/data/repositories.rs

@@ -5,6 +5,8 @@ use parking_lot::{Mutex, RwLock};
 use rusqlite::Connection;
 use std::marker::PhantomData;
 use std::ops::Deref;
+use std::rc::Weak;
+use std::slice::Iter;
 use std::sync::Arc;
 
 pub trait Repository<T, D>
@@ -20,6 +22,32 @@ where
     fn delete(&mut self, handle: EntityHandle<T>) -> MaybeError;
     fn init(&mut self) -> MaybeError;
     fn reload(&mut self) -> MaybeError;
+    fn query(&mut self, rule: fn(&T) -> bool) -> Query<T, Self, D> where Self: Sized;
+}
+
+struct QueryManger<T, R, D>
+where
+    R: Repository<T, D>,
+    D: DbLayer<T>,
+{
+    queries: Mutex<Vec<Weak<Query<T, R, D>>>>,
+}
+
+pub struct Query<T, R, D>
+where
+    R: Repository<T, D>, D: DbLayer<T>
+{
+    cache: Vec<EntityHandle<T>>,
+    rule: fn(&T) -> bool,
+    repo: Arc<R>,
+    _marker: PhantomData<D>,
+}
+
+impl<T, R: Repository<T, D>, D: DbLayer<T>> Query<T, R, D>
+{
+    fn iter<'a>(&mut self, data_repository_inner: &'a R) -> Iter<'_, &'a T> {
+        self.cache.iter_mut().filter_map(|e| data_repository_inner.get_ref(e))
+    }
 }
 
 pub trait BatchedRepository<T, D>
@@ -47,19 +75,20 @@ where
 }
 
 #[derive(Clone)]
-pub struct DataRepository<T, D> {
+pub struct DataRepository<T: std::clone::Clone + EntityData, D: DbLayer<T>> {
     inner: Arc<RwLock<DataRepositoryInner<T, D>>>,
 }
 
-pub struct DataRepositoryInner<T, D> {
+pub struct DataRepositoryInner<T: std::clone::Clone + EntityData, D: DbLayer<T>> {
     cache: Vec<T>,
     temporal: Vec<T>,
     next_temporal: u32,
     connection: Arc<Mutex<Connection>>,
     data_layer: D,
+    query_manger: QueryManger<T, Self, D>
 }
 
-impl<T, D> Deref for DataRepository<T, D> {
+impl<T: std::clone::Clone + EntityData, D: DbLayer<T>> Deref for DataRepository<T, D> {
     type Target = Arc<RwLock<DataRepositoryInner<T, D>>>;
 
     fn deref(&self) -> &Self::Target {
@@ -196,9 +225,13 @@ impl<T: EntityData + Clone, D: DbLayer<T>> Repository<T, D> for DataRepositoryIn
         self.init()?;
         Ok(())
     }
+
+    fn query(&mut self, rule: fn(&T) -> bool) -> Query<T, Self, D> {
+        todo!()
+    }
 }
 impl<T: EntityData + Clone, D: BatchedDbLayer<T> + DbLayer<T>> BatchedRepository<T, D>
-for DataRepositoryInner<T, D>
+    for DataRepositoryInner<T, D>
 {
     fn save_many(&mut self, handles: &mut [EntityHandle<T>]) -> MaybeError {
         let mut temp = Vec::with_capacity(handles.len() / 2);