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-rw-r--r--embassy-sync/src/ring_buffer.rs46
1 files changed, 19 insertions, 27 deletions
diff --git a/embassy-sync/src/ring_buffer.rs b/embassy-sync/src/ring_buffer.rs
index 521084024..d95ffa7c9 100644
--- a/embassy-sync/src/ring_buffer.rs
+++ b/embassy-sync/src/ring_buffer.rs
@@ -1,5 +1,6 @@
1use core::ops::Range;
2
1pub struct RingBuffer<const N: usize> { 3pub struct RingBuffer<const N: usize> {
2 buf: [u8; N],
3 start: usize, 4 start: usize,
4 end: usize, 5 end: usize,
5 empty: bool, 6 empty: bool,
@@ -8,27 +9,26 @@ pub struct RingBuffer<const N: usize> {
8impl<const N: usize> RingBuffer<N> { 9impl<const N: usize> RingBuffer<N> {
9 pub const fn new() -> Self { 10 pub const fn new() -> Self {
10 Self { 11 Self {
11 buf: [0; N],
12 start: 0, 12 start: 0,
13 end: 0, 13 end: 0,
14 empty: true, 14 empty: true,
15 } 15 }
16 } 16 }
17 17
18 pub fn push_buf(&mut self) -> &mut [u8] { 18 pub fn push_buf(&mut self) -> Range<usize> {
19 if self.start == self.end && !self.empty { 19 if self.start == self.end && !self.empty {
20 trace!(" ringbuf: push_buf empty"); 20 trace!(" ringbuf: push_buf empty");
21 return &mut self.buf[..0]; 21 return 0..0;
22 } 22 }
23 23
24 let n = if self.start <= self.end { 24 let n = if self.start <= self.end {
25 self.buf.len() - self.end 25 N - self.end
26 } else { 26 } else {
27 self.start - self.end 27 self.start - self.end
28 }; 28 };
29 29
30 trace!(" ringbuf: push_buf {:?}..{:?}", self.end, self.end + n); 30 trace!(" ringbuf: push_buf {:?}..{:?}", self.end, self.end + n);
31 &mut self.buf[self.end..self.end + n] 31 self.end..self.end + n
32 } 32 }
33 33
34 pub fn push(&mut self, n: usize) { 34 pub fn push(&mut self, n: usize) {
@@ -41,20 +41,20 @@ impl<const N: usize> RingBuffer<N> {
41 self.empty = false; 41 self.empty = false;
42 } 42 }
43 43
44 pub fn pop_buf(&mut self) -> &mut [u8] { 44 pub fn pop_buf(&mut self) -> Range<usize> {
45 if self.empty { 45 if self.empty {
46 trace!(" ringbuf: pop_buf empty"); 46 trace!(" ringbuf: pop_buf empty");
47 return &mut self.buf[..0]; 47 return 0..0;
48 } 48 }
49 49
50 let n = if self.end <= self.start { 50 let n = if self.end <= self.start {
51 self.buf.len() - self.start 51 N - self.start
52 } else { 52 } else {
53 self.end - self.start 53 self.end - self.start
54 }; 54 };
55 55
56 trace!(" ringbuf: pop_buf {:?}..{:?}", self.start, self.start + n); 56 trace!(" ringbuf: pop_buf {:?}..{:?}", self.start, self.start + n);
57 &mut self.buf[self.start..self.start + n] 57 self.start..self.start + n
58 } 58 }
59 59
60 pub fn pop(&mut self, n: usize) { 60 pub fn pop(&mut self, n: usize) {
@@ -93,8 +93,8 @@ impl<const N: usize> RingBuffer<N> {
93 } 93 }
94 94
95 fn wrap(&self, n: usize) -> usize { 95 fn wrap(&self, n: usize) -> usize {
96 assert!(n <= self.buf.len()); 96 assert!(n <= N);
97 if n == self.buf.len() { 97 if n == N {
98 0 98 0
99 } else { 99 } else {
100 n 100 n
@@ -110,37 +110,29 @@ mod tests {
110 fn push_pop() { 110 fn push_pop() {
111 let mut rb: RingBuffer<4> = RingBuffer::new(); 111 let mut rb: RingBuffer<4> = RingBuffer::new();
112 let buf = rb.push_buf(); 112 let buf = rb.push_buf();
113 assert_eq!(4, buf.len()); 113 assert_eq!(0..4, buf);
114 buf[0] = 1;
115 buf[1] = 2;
116 buf[2] = 3;
117 buf[3] = 4;
118 rb.push(4); 114 rb.push(4);
119 115
120 let buf = rb.pop_buf(); 116 let buf = rb.pop_buf();
121 assert_eq!(4, buf.len()); 117 assert_eq!(0..4, buf);
122 assert_eq!(1, buf[0]);
123 rb.pop(1); 118 rb.pop(1);
124 119
125 let buf = rb.pop_buf(); 120 let buf = rb.pop_buf();
126 assert_eq!(3, buf.len()); 121 assert_eq!(1..4, buf);
127 assert_eq!(2, buf[0]);
128 rb.pop(1); 122 rb.pop(1);
129 123
130 let buf = rb.pop_buf(); 124 let buf = rb.pop_buf();
131 assert_eq!(2, buf.len()); 125 assert_eq!(2..4, buf);
132 assert_eq!(3, buf[0]);
133 rb.pop(1); 126 rb.pop(1);
134 127
135 let buf = rb.pop_buf(); 128 let buf = rb.pop_buf();
136 assert_eq!(1, buf.len()); 129 assert_eq!(3..4, buf);
137 assert_eq!(4, buf[0]);
138 rb.pop(1); 130 rb.pop(1);
139 131
140 let buf = rb.pop_buf(); 132 let buf = rb.pop_buf();
141 assert_eq!(0, buf.len()); 133 assert_eq!(0..0, buf);
142 134
143 let buf = rb.push_buf(); 135 let buf = rb.push_buf();
144 assert_eq!(4, buf.len()); 136 assert_eq!(0..4, buf);
145 } 137 }
146} 138}