From 4313b5b0bfa79f4eaed25b65c5a7154c16074208 Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Sun, 28 Jul 2024 19:46:01 +0200
Subject: refactor(ecs): move ArchetypeComponentsHash to archetype::Id

---
 ecs/src/archetype.rs         | 27 +++++++++++++++++++++++++++
 ecs/src/component/storage.rs | 39 +++++++++------------------------------
 ecs/src/lib.rs               |  2 ++
 3 files changed, 38 insertions(+), 30 deletions(-)
 create mode 100644 ecs/src/archetype.rs

(limited to 'ecs/src')

diff --git a/ecs/src/archetype.rs b/ecs/src/archetype.rs
new file mode 100644
index 0000000..a33de66
--- /dev/null
+++ b/ecs/src/archetype.rs
@@ -0,0 +1,27 @@
+use std::hash::{DefaultHasher, Hash, Hasher};
+
+use crate::component::Id as ComponentId;
+
+/// Archetype ID.
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Id
+{
+    hash: u64,
+}
+
+impl Id
+{
+    /// Returns the ID of a archetype with the given components.
+    pub fn new(component_ids: impl IntoIterator<Item = ComponentId>) -> Self
+    {
+        let mut hasher = DefaultHasher::new();
+
+        for component_id in component_ids {
+            component_id.hash(&mut hasher);
+        }
+
+        let hash = hasher.finish();
+
+        Self { hash }
+    }
+}
diff --git a/ecs/src/component/storage.rs b/ecs/src/component/storage.rs
index cff50cf..1db9227 100644
--- a/ecs/src/component/storage.rs
+++ b/ecs/src/component/storage.rs
@@ -1,8 +1,8 @@
 use std::any::type_name;
 use std::collections::{HashMap, HashSet};
-use std::hash::{DefaultHasher, Hash, Hasher};
 use std::slice::Iter as SliceIter;
 
+use crate::archetype::Id as ArchetypeId;
 use crate::component::{Component, Id as ComponentId, IsOptional as ComponentIsOptional};
 use crate::lock::Lock;
 use crate::type_name::TypeName;
@@ -12,7 +12,7 @@ use crate::EntityComponent;
 pub struct Storage
 {
     archetypes: Vec<Archetype>,
-    archetype_lookup: HashMap<ArchetypeComponentsHash, Vec<usize>>,
+    archetype_lookup: HashMap<ArchetypeId, Vec<usize>>,
     pending_archetype_lookup_entries: Vec<Vec<ComponentId>>,
 }
 
@@ -34,7 +34,7 @@ impl Storage
             });
 
         self.archetype_lookup
-            .get(&ArchetypeComponentsHash::new(ids))
+            .get(&ArchetypeId::new(ids))
             .map_or_else(ArchetypeRefIter::new_empty, |archetypes_indices| {
                 ArchetypeRefIter {
                     inner: archetypes_indices.iter(),
@@ -58,7 +58,7 @@ impl Storage
 
         let archetype_indices = self
             .archetype_lookup
-            .entry(ArchetypeComponentsHash::new(
+            .entry(ArchetypeId::new(
                 components
                     .iter()
                     .filter(|component| !component.is_optional())
@@ -131,7 +131,7 @@ impl Storage
 
             let archetype_indices = self
                 .archetype_lookup
-                .entry(ArchetypeComponentsHash::new(pending_entry.into_iter()))
+                .entry(ArchetypeId::new(pending_entry.into_iter()))
                 .or_default();
 
             archetype_indices.extend(matching_archetype_indices);
@@ -185,28 +185,6 @@ impl<'component_storage> Iterator for ArchetypeRefIter<'component_storage>
     }
 }
 
-#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
-struct ArchetypeComponentsHash
-{
-    hash: u64,
-}
-
-impl ArchetypeComponentsHash
-{
-    fn new(component_ids: impl IntoIterator<Item = ComponentId>) -> Self
-    {
-        let mut hasher = DefaultHasher::new();
-
-        for component_id in component_ids {
-            component_id.hash(&mut hasher);
-        }
-
-        let hash = hasher.finish();
-
-        Self { hash }
-    }
-}
-
 #[cfg(test)]
 mod tests
 {
@@ -214,7 +192,8 @@ mod tests
 
     use ecs_macros::Component;
 
-    use super::{Archetype, ArchetypeComponentsHash, Storage};
+    use super::{Archetype, Storage};
+    use crate::archetype::Id as ArchetypeId;
     use crate::component::Id as ComponentId;
     use crate::lock::Lock;
     use crate::{self as ecs, EntityComponent};
@@ -279,7 +258,7 @@ mod tests
 
         let lookup = component_storage
             .archetype_lookup
-            .get(&ArchetypeComponentsHash::new([
+            .get(&ArchetypeId::new([
                 ComponentId::of::<HealthPotion>(),
                 ComponentId::of::<Hookshot>(),
             ]))
@@ -366,7 +345,7 @@ mod tests
 
         let archetypes = component_storage
             .archetype_lookup
-            .get(&ArchetypeComponentsHash::new([
+            .get(&ArchetypeId::new([
                 ComponentId::of::<IronBoots>(),
                 ComponentId::of::<Hookshot>(),
             ]))
diff --git a/ecs/src/lib.rs b/ecs/src/lib.rs
index a33d72e..95519c9 100644
--- a/ecs/src/lib.rs
+++ b/ecs/src/lib.rs
@@ -31,6 +31,8 @@ pub mod system;
 pub mod tuple;
 pub mod type_name;
 
+mod archetype;
+
 pub use ecs_macros::{Component, Sole};
 
 pub use crate::query::Query;
-- 
cgit v1.2.3-18-g5258