Merge pull request #4 from arindas/develop

feat: improves documentation and tests on arena

Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT"
 keywords = ["cache", "lru-cache", "generational-arena", "no-std"]
 categories = ["algorithms", "caching"]
 exclude = [".github/"]
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

README.md

@@ -27,7 +27,7 @@ Generational Arena based cache impls. in 100% safe, [no_std] compatible Rust.
 
 ```toml
 [dependencies]
-generational-cache = "0.1.0"
+generational-cache = "0.1.1"
 ```
 
 Refer to latest git [API Documentation](https://arindas.github.io/generational-cache/docs/generational_cache/)
@@ -98,4 +98,6 @@ match cache.insert(0, 0) {
 (… we plan on adding more cache implementations in the future).
 
 ## License
-This repository is licensed under the MIT License. See [LICENSE](./LICENSE) for more details.
+This repository is licensed under the MIT License. See
+[License](https://raw.githubusercontent.com/arindas/generational-cache/main/LICENSE)
+for more details.

src/arena/mod.rs

@@ -54,12 +54,34 @@ impl<T> Default for Entry<T> {
 ///
 /// This is inspired from the crate
 /// ["generational-arena"](https://docs.rs/generational-arena)
+///
+/// ## Usage
+/// ```
+/// #[no_std]
+///
+/// use generational_cache::prelude::*;
+///
+/// const CAPACITY: usize = 5;
+///
+/// let mut arena = Arena::<_, i32>::with_vector(Array::<_, CAPACITY>::new());
+/// let index = arena.insert(78).unwrap(); // allocate new element in arena
+/// let i_ref = arena.get(&index);
+/// assert_eq!(i_ref, Some(&78));
+/// let i_m_ref = arena.get_mut(&index).unwrap();
+/// *i_m_ref = -68418;
+/// assert_eq!(arena.get(&index), Some(&-68418));
+///
+/// arena.remove(&index).unwrap();
+///
+/// assert!(arena.get(&index).is_none());
+/// ```
 pub struct Arena<V, T> {
     entries_vec: V,
     generation: u64,
     free_list_head: Option<usize>,
 
     len: usize,
+    capacity: usize,
 
     _phantom_type: PhantomData<T>,
 }
@@ -92,7 +114,7 @@ where
 
         self.entries_vec.clear();
 
-        let capacity = self.entries_vec.capacity();
+        let capacity = self.capacity();
 
         for i in 0..capacity {
             let next_free_idx = i + 1;
@@ -112,11 +134,14 @@ where
     }
 
     pub fn with_vector(vector: V) -> Self {
+        let capacity = vector.capacity();
+
         let mut arena = Self {
             entries_vec: vector,
             generation: 0,
             free_list_head: Some(0),
             len: 0,
+            capacity,
             _phantom_type: PhantomData,
         };
 
@@ -207,7 +232,7 @@ where
     }
 
     pub fn capacity(&self) -> usize {
-        self.entries_vec.capacity()
+        self.capacity
     }
 
     pub fn is_empty(&self) -> bool {

src/vector/mod.rs

@@ -43,11 +43,18 @@ pub mod tests {
         if cap_0 == cap_1 {
             assert!(res.is_err());
         } else {
+            assert!(cap_1 > cap_0, "Capacity decreased on push().");
             assert!(res.is_ok());
         }
 
+        let cap_0 = vector.capacity();
+
         vector.clear();
 
+        let cap_1 = vector.capacity();
+
+        assert!(cap_0 == cap_1, "Capacity changed on clear().");
+
         assert!(vector.is_empty());
     }
 }