ringbuf/traits/
ring_buffer.rs

1use super::{
2    consumer::{Consumer, DelegateConsumer},
3    producer::{DelegateProducer, Producer},
4    Observer,
5};
6
7/// An abstract ring buffer that exclusively owns its data.
8pub trait RingBuffer: Observer + Consumer + Producer {
9    /// Tell whether read end of the ring buffer is held by consumer or not.
10    ///
11    /// Returns old value.
12    ///
13    /// # Safety
14    ///
15    /// Must not be set to `false` while consumer exists.
16    unsafe fn hold_read(&self, flag: bool) -> bool;
17    /// Tell whether write end of the ring buffer is held by producer or not.
18    ///
19    /// Returns old value.
20    ///
21    /// # Safety
22    ///
23    /// Must not be set to `false` while producer exists.
24    unsafe fn hold_write(&self, flag: bool) -> bool;
25
26    /// Pushes an item to the ring buffer overwriting the latest item if the buffer is full.
27    ///
28    /// Returns overwritten item if overwriting took place.
29    fn push_overwrite(&mut self, elem: Self::Item) -> Option<Self::Item> {
30        let ret = if self.is_full() { self.try_pop() } else { None };
31        let _ = self.try_push(elem);
32        ret
33    }
34
35    /// Appends items from an iterator to the ring buffer.
36    ///
37    /// *This method consumes iterator until its end.*
38    /// Exactly last `min(iter.len(), capacity)` items from the iterator will be stored in the ring buffer.
39    fn push_iter_overwrite<I: Iterator<Item = Self::Item>>(&mut self, iter: I) {
40        for elem in iter {
41            self.push_overwrite(elem);
42        }
43    }
44
45    /// Appends items from slice to the ring buffer overwriting existing items in the ring buffer.
46    ///
47    /// If the slice length is greater than ring buffer capacity then only last `capacity` items from slice will be stored in the buffer.
48    fn push_slice_overwrite(&mut self, elems: &[Self::Item])
49    where
50        Self::Item: Copy,
51    {
52        if elems.len() > self.vacant_len() {
53            self.skip(usize::min(elems.len() - self.vacant_len(), self.occupied_len()));
54        }
55        self.push_slice(if elems.len() > self.vacant_len() {
56            &elems[(elems.len() - self.vacant_len())..]
57        } else {
58            elems
59        });
60    }
61}
62
63/// Trait used for delegating owning ring buffer methods.
64pub trait DelegateRingBuffer: DelegateProducer + DelegateConsumer
65where
66    Self::Base: RingBuffer,
67{
68}
69
70impl<D: DelegateRingBuffer> RingBuffer for D
71where
72    D::Base: RingBuffer,
73{
74    unsafe fn hold_read(&self, flag: bool) -> bool {
75        self.base().hold_read(flag)
76    }
77    unsafe fn hold_write(&self, flag: bool) -> bool {
78        self.base().hold_write(flag)
79    }
80
81    #[inline]
82    fn push_overwrite(&mut self, elem: Self::Item) -> Option<Self::Item> {
83        self.base_mut().push_overwrite(elem)
84    }
85
86    #[inline]
87    fn push_iter_overwrite<I: Iterator<Item = Self::Item>>(&mut self, iter: I) {
88        self.base_mut().push_iter_overwrite(iter)
89    }
90
91    #[inline]
92    fn push_slice_overwrite(&mut self, elems: &[Self::Item])
93    where
94        Self::Item: Copy,
95    {
96        self.base_mut().push_slice_overwrite(elems)
97    }
98}
ringbuf/traits/ring_buffer.rs

ringbuf/traits/
ring_buffer.rs
