cinderblock_core/data_layer/
in_memory.rs

1use std::{
2    any::{Any, TypeId},
3    collections::HashMap,
4    sync::{Arc, LazyLock},
5};
6
7use tokio::sync::RwLock;
8
9use crate::{PerformRead, ReadAction, Resource, data_layer::DataLayer};
10
11type State =
12    LazyLock<Arc<RwLock<HashMap<TypeId, HashMap<String, Box<dyn Any + Send + Sync + 'static>>>>>>;
13
14static STATE: State = LazyLock::new(Arc::default);
15
16#[derive(Debug)]
17pub struct InMemoryDataLayer {}
18impl InMemoryDataLayer {
19    pub(crate) fn new() -> Self {
20        Self {}
21    }
22}
23
24impl<R: Resource + 'static> DataLayer<R> for InMemoryDataLayer {
25    async fn create(&self, resource: R) -> crate::Result<()> {
26        let state = STATE.clone();
27        let mut state = state.write().await;
28
29        let map = state.entry(TypeId::of::<R>()).or_default();
30        map.insert(
31            resource.primary_key().to_string(),
32            Box::new(resource.clone()),
33        );
34
35        Ok(())
36    }
37
38    async fn read(&self, primary_key: &R::PrimaryKey) -> crate::Result<R> {
39        let state = STATE.clone();
40        let state = state.read().await;
41
42        let key = primary_key.to_string();
43
44        state
45            .get(&TypeId::of::<R>())
46            .and_then(|map| map.get(&key))
47            .and_then(|boxed| boxed.downcast_ref::<R>())
48            .cloned()
49            .ok_or_else(|| format!("resource not found for primary key `{key}`").into())
50    }
51
52    async fn update(&self, resource: R) -> crate::Result<()> {
53        let state = STATE.clone();
54        let mut state = state.write().await;
55
56        let key = resource.primary_key().to_string();
57
58        let map = state
59            .get_mut(&TypeId::of::<R>())
60            .ok_or_else(|| format!("resource not found for primary key `{key}`"))?;
61
62        if !map.contains_key(&key) {
63            return Err(format!("resource not found for primary key `{key}`").into());
64        }
65
66        map.insert(key, Box::new(resource.clone()));
67
68        Ok(())
69    }
70
71    async fn destroy(&self, primary_key: &R::PrimaryKey) -> crate::Result<R> {
72        let state = STATE.clone();
73        let mut state = state.write().await;
74
75        let key = primary_key.to_string();
76
77        let map = state
78            .get_mut(&TypeId::of::<R>())
79            .ok_or_else(|| format!("resource not found for primary key `{key}`"))?;
80
81        let boxed = map
82            .remove(&key)
83            .ok_or_else(|| format!("resource not found for primary key `{key}`"))?;
84
85        boxed
86            .downcast::<R>()
87            .map(|r| *r)
88            .map_err(|_| "failed to downcast destroyed resource".into())
89    }
90}
91
92pub trait InMemoryReadAction: ReadAction {
93    fn filter(row: &Self::Output, args: &Self::Arguments) -> bool;
94}
95
96impl<R, A> PerformRead<A> for InMemoryDataLayer
97where
98    R: Resource + 'static,
99    A: ReadAction<Output = R> + InMemoryReadAction + 'static,
100{
101    async fn read(&self, args: &A::Arguments) -> crate::Result<Vec<A::Output>> {
102        let state = STATE.clone();
103        let state = state.read().await;
104
105        Ok(state
106            .get(&TypeId::of::<R>())
107            .iter()
108            .flat_map(|map| map.values())
109            .filter_map(|boxed| boxed.downcast_ref::<R>())
110            .filter(|row| A::filter(row, args))
111            .cloned()
112            .collect())
113    }
114}
cinderblock_core/data_layer/in_memory.rs

cinderblock_core/data_layer/
in_memory.rs
