webrender/prim_store/
storage.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
4
5use std::{ops, marker::PhantomData, u32};
6use crate::util::Recycler;
7
8#[derive(Debug, Hash)]
9#[cfg_attr(feature = "capture", derive(Serialize))]
10#[cfg_attr(feature = "replay", derive(Deserialize))]
11pub struct Index<T>(u32, PhantomData<T>);
12
13// We explicitly implement Copy + Clone instead of using #[derive(Copy, Clone)]
14// because we don't want to require that T implements Clone + Copy.
15impl<T> Clone for Index<T> {
16    fn clone(&self) -> Self { *self }
17}
18
19impl<T> Copy for Index<T> {}
20
21impl<T> PartialEq for Index<T> {
22    fn eq(&self, other: &Self) -> bool {
23        self.0 == other.0
24    }
25}
26
27impl<T> Index<T> {
28    fn new(idx: usize) -> Self {
29        debug_assert!(idx < u32::max_value() as usize);
30        Index(idx as u32, PhantomData)
31    }
32
33    pub const INVALID: Index<T> = Index(u32::MAX, PhantomData);
34    pub const UNUSED: Index<T> = Index(u32::MAX-1, PhantomData);
35}
36
37#[derive(Debug)]
38pub struct OpenRange<T> {
39    start: Index<T>,
40}
41
42#[derive(Debug)]
43#[cfg_attr(feature = "capture", derive(Serialize))]
44pub struct Range<T> {
45    pub start: Index<T>,
46    pub end: Index<T>,
47}
48
49// We explicitly implement Copy + Clone instead of using #[derive(Copy, Clone)]
50// because we don't want to require that T implements Clone + Copy.
51impl<T> Clone for Range<T> {
52    fn clone(&self) -> Self {
53        Range { start: self.start, end: self.end }
54    }
55}
56impl<T> Copy for Range<T> {}
57
58impl<T> Range<T> {
59    /// Create an empty `Range`
60    pub fn empty() -> Self {
61        Range {
62            start: Index::new(0),
63            end: Index::new(0),
64        }
65    }
66
67    /// Check for an empty `Range`
68    pub fn is_empty(self) -> bool {
69        self.start.0 >= self.end.0
70    }
71}
72
73#[cfg_attr(feature = "capture", derive(Serialize))]
74pub struct Storage<T> {
75    data: Vec<T>,
76}
77
78impl<T> Storage<T> {
79    pub fn new(initial_capacity: usize) -> Self {
80        Storage {
81            data: Vec::with_capacity(initial_capacity),
82        }
83    }
84
85    pub fn len(&self) -> usize {
86        self.data.len()
87    }
88
89    pub fn clear(&mut self) {
90        self.data.clear();
91    }
92
93    pub fn push(&mut self, t: T) -> Index<T> {
94        let index = self.data.len();
95        self.data.push(t);
96        Index(index as u32, PhantomData)
97    }
98
99    pub fn reserve(&mut self, count: usize) {
100        self.data.reserve(count);
101    }
102
103    pub fn recycle(&mut self, recycler: &mut Recycler) {
104        recycler.recycle_vec(&mut self.data);
105    }
106
107    pub fn extend<II: IntoIterator<Item=T>>(&mut self, iter: II) -> Range<T> {
108        let range = self.open_range();
109        self.data.extend(iter);
110
111        self.close_range(range)
112    }
113
114    pub fn open_range(&self) -> OpenRange<T> {
115        OpenRange {
116            start: Index::new(self.data.len())
117        }
118    }
119
120    pub fn close_range(&self, range: OpenRange<T>) -> Range<T> {
121        Range {
122            start: range.start,
123            end: Index::new(self.data.len()),
124        }
125    }
126}
127
128impl<T> ops::Index<Index<T>> for Storage<T> {
129    type Output = T;
130    fn index(&self, index: Index<T>) -> &Self::Output {
131        &self.data[index.0 as usize]
132    }
133}
134
135impl<T> ops::IndexMut<Index<T>> for Storage<T> {
136    fn index_mut(&mut self, index: Index<T>) -> &mut Self::Output {
137        &mut self.data[index.0 as usize]
138    }
139}
140
141impl<T> ops::Index<Range<T>> for Storage<T> {
142    type Output = [T];
143    fn index(&self, index: Range<T>) -> &Self::Output {
144        let start = index.start.0 as _;
145        let end = index.end.0 as _;
146        &self.data[start..end]
147    }
148}
149
150impl<T> ops::IndexMut<Range<T>> for Storage<T> {
151    fn index_mut(&mut self, index: Range<T>) -> &mut Self::Output {
152        let start = index.start.0 as _;
153        let end = index.end.0 as _;
154        &mut self.data[start..end]
155    }
156}
webrender/prim_store/storage.rs

webrender/prim_store/
storage.rs
