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
|
/// Wrapper around Vec which supports fast indexing and rotation
///
/// The rotation implemented by grid::Storage is a simple integer addition.
/// Compare with standard library rotation which requires rearranging items in
/// memory.
///
/// As a consequence, the indexing operators need to be reimplemented for this
/// type to account for the 0th element not always being at the start of the
/// allocation.
///
/// Because certain Vec operations are no longer valid on this type, no Deref
/// implementation is provided. Anything from Vec that should be exposed must be
/// done so manually.
use std::ops::{Index, IndexMut};
use index::{IndexRange, Line};
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct Storage<T> {
inner: Vec<T>,
zero: usize,
visible_lines: Line,
}
impl<T: PartialEq> ::std::cmp::PartialEq for Storage<T> {
fn eq(&self, other: &Self) -> bool {
let mut equal = true;
for i in IndexRange(Line(0) .. self.visible_lines) {
equal = equal && (self[i] == other[i])
}
equal
}
}
impl<T> Storage<T> {
#[inline]
pub fn with_capacity(cap: usize, lines: Line) -> Storage<T> {
Storage {
inner: Vec::with_capacity(cap),
zero: 0,
visible_lines: lines - 1,
}
}
#[inline]
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
pub fn set_visible_lines(&mut self, next: Line) {
self.visible_lines = next - 1;
}
#[inline]
pub fn push(&mut self, item: T) {
self.inner.push(item)
}
#[inline]
pub fn pop(&mut self) -> Option<T> {
self.inner.pop()
}
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Compute actual index in underlying storage given the requested index.
#[inline]
fn compute_index(&self, requested: usize) -> usize {
(requested + self.zero) % self.len()
}
fn compute_line_index(&self, requested: Line) -> usize {
((self.len() + self.zero + *self.visible_lines) - *requested) % self.len()
}
pub fn swap(&mut self, a: usize, b: usize) {
let a = self.compute_index(a);
let b = self.compute_index(b);
self.inner.swap(a, b);
}
pub fn swap_lines(&mut self, a: Line, b: Line) {
let a = self.compute_line_index(a);
let b = self.compute_line_index(b);
self.inner.swap(a, b);
}
pub fn iter_mut(&mut self) -> IterMut<T> {
IterMut { storage: self, index: 0 }
}
pub fn rotate(&mut self, count: isize) {
let len = self.len();
assert!(count.abs() as usize <= len);
self.zero += (count + len as isize) as usize % len;
}
// Fast path
pub fn rotate_up(&mut self, count: usize) {
self.zero = (self.zero + count) % self.len();
}
}
impl<T> Index<usize> for Storage<T> {
type Output = T;
#[inline]
fn index(&self, index: usize) -> &T {
let index = self.compute_index(index); // borrowck
&self.inner[index]
}
}
impl<T> IndexMut<usize> for Storage<T> {
#[inline]
fn index_mut(&mut self, index: usize) -> &mut T {
let index = self.compute_index(index); // borrowck
&mut self.inner[index]
}
}
impl<T> Index<Line> for Storage<T> {
type Output = T;
#[inline]
fn index(&self, index: Line) -> &T {
let index = self.visible_lines - index;
&self[*index]
}
}
impl<T> IndexMut<Line> for Storage<T> {
#[inline]
fn index_mut(&mut self, index: Line) -> &mut T {
let index = self.visible_lines - index;
&mut self[*index]
}
}
pub struct IterMut<'a, T: 'a> {
storage: &'a mut Storage<T>,
index: usize,
}
impl<'a, T: 'a> Iterator for IterMut<'a, T> {
type Item = &'a mut T;
fn next(&mut self) -> Option<Self::Item> {
if self.index == self.storage.len() {
None
} else {
let index = self.index;
self.index += 1;
unsafe {
Some(&mut *(&mut self.storage[index] as *mut _))
}
}
}
}
|
