1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
use std::{
cell::RefCell,
collections::HashMap,
fmt::Debug,
hash::BuildHasherDefault,
num::NonZeroU64,
sync::atomic::{AtomicU64, Ordering},
};
use super::{
hash::U64Hasher,
storage::{archetype::ArchetypeIndex, ComponentIndex},
};
#[derive(Debug, Copy, PartialEq, Eq, Hash)]
#[repr(transparent)]
pub struct Entity(NonZeroU64);
thread_local! {
pub static ID_CLONE_MAPPINGS: RefCell<HashMap<Entity, Entity, EntityHasher>> = RefCell::new(HashMap::default());
}
impl Clone for Entity {
fn clone(&self) -> Self {
ID_CLONE_MAPPINGS.with(|cell| {
let map = cell.borrow();
*map.get(self).unwrap_or(self)
})
}
}
const BLOCK_SIZE: u64 = 16;
const BLOCK_SIZE_USIZE: usize = BLOCK_SIZE as usize;
static NEXT_ENTITY: AtomicU64 = AtomicU64::new(BLOCK_SIZE);
#[derive(Debug)]
pub struct Allocate {
next: u64,
}
impl Allocate {
pub fn new() -> Self {
Self { next: 0 }
}
}
impl Default for Allocate {
fn default() -> Self {
Self::new()
}
}
impl<'a> Iterator for Allocate {
type Item = Entity;
#[inline(always)]
fn next(&mut self) -> Option<Self::Item> {
if self.next % BLOCK_SIZE == 0 {
self.next = NEXT_ENTITY.fetch_add(BLOCK_SIZE, Ordering::Relaxed);
debug_assert_eq!(self.next % BLOCK_SIZE, 0);
}
let entity = unsafe {
debug_assert_ne!(self.next, 0);
Entity(NonZeroU64::new_unchecked(self.next))
};
self.next += 1;
Some(entity)
}
}
#[derive(Debug, Copy, Clone)]
pub struct EntityLocation(pub(crate) ArchetypeIndex, pub(crate) ComponentIndex);
impl EntityLocation {
pub fn new(archetype: ArchetypeIndex, component: ComponentIndex) -> Self {
EntityLocation(archetype, component)
}
pub fn archetype(&self) -> ArchetypeIndex {
self.0
}
pub fn component(&self) -> ComponentIndex {
self.1
}
}
pub type EntityHasher = BuildHasherDefault<U64Hasher>;
#[derive(Clone, Default)]
pub struct LocationMap {
len: usize,
blocks: HashMap<u64, Box<[Option<EntityLocation>; BLOCK_SIZE_USIZE]>, EntityHasher>,
}
impl Debug for LocationMap {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let entries = self.blocks.iter().flat_map(|(base, locs)| {
locs.iter().enumerate().filter_map(move |(i, loc)| {
let entity = unsafe {
let id = *base + i as u64;
debug_assert_ne!(id, 0);
Entity(NonZeroU64::new_unchecked(id))
};
loc.map(|loc| (entity, loc))
})
});
f.debug_map().entries(entries).finish()
}
}
impl LocationMap {
pub fn len(&self) -> usize {
self.len
}
pub fn is_empty(&self) -> bool {
self.len() == 0
}
pub fn contains(&self, entity: Entity) -> bool {
self.get(entity).is_some()
}
pub fn insert(
&mut self,
ids: &[Entity],
arch: ArchetypeIndex,
ComponentIndex(base): ComponentIndex,
) -> Vec<EntityLocation> {
let mut current_block = u64::MAX;
let mut block_vec = None;
let mut removed = Vec::new();
for (i, entity) in ids.iter().enumerate() {
let block = entity.0.get() / BLOCK_SIZE;
if current_block != block {
block_vec = Some(
self.blocks
.entry(block)
.or_insert_with(|| Box::new([None; BLOCK_SIZE_USIZE])),
);
current_block = block;
}
if let Some(ref mut vec) = block_vec {
let idx = (entity.0.get() % BLOCK_SIZE) as usize;
let loc = EntityLocation(arch, ComponentIndex(base + i));
if let Some(previous) = vec[idx].replace(loc) {
removed.push(previous);
}
}
}
self.len += ids.len() - removed.len();
removed
}
pub fn set(&mut self, entity: Entity, location: EntityLocation) {
self.insert(&[entity], location.archetype(), location.component());
}
pub fn get(&self, entity: Entity) -> Option<EntityLocation> {
let block = entity.0.get() / BLOCK_SIZE;
let idx = (entity.0.get() % BLOCK_SIZE) as usize;
if let Some(&result) = self.blocks.get(&block).and_then(|v| v.get(idx)) {
result
} else {
None
}
}
pub fn remove(&mut self, entity: Entity) -> Option<EntityLocation> {
let block = entity.0.get() / BLOCK_SIZE;
let idx = (entity.0.get() % BLOCK_SIZE) as usize;
if let Some(loc) = self.blocks.get_mut(&block).and_then(|v| v.get_mut(idx)) {
let original = loc.take();
if original.is_some() {
self.len -= 1;
}
original
} else {
None
}
}
}