qmk_firmware/drivers/bluetooth/ringbuffer.hpp
2021-09-21 19:58:46 +10:00

67 lines
1.2 KiB
C++

#pragma once
// A simple ringbuffer holding Size elements of type T
template <typename T, uint8_t Size>
class RingBuffer {
protected:
T buf_[Size];
uint8_t head_{0}, tail_{0};
public:
inline uint8_t nextPosition(uint8_t position) {
return (position + 1) % Size;
}
inline uint8_t prevPosition(uint8_t position) {
if (position == 0) {
return Size - 1;
}
return position - 1;
}
inline bool enqueue(const T &item) {
static_assert(Size > 1, "RingBuffer size must be > 1");
uint8_t next = nextPosition(head_);
if (next == tail_) {
// Full
return false;
}
buf_[head_] = item;
head_ = next;
return true;
}
inline bool get(T &dest, bool commit = true) {
auto tail = tail_;
if (tail == head_) {
// No more data
return false;
}
dest = buf_[tail];
tail = nextPosition(tail);
if (commit) {
tail_ = tail;
}
return true;
}
inline bool empty() const { return head_ == tail_; }
inline uint8_t size() const {
int diff = head_ - tail_;
if (diff >= 0) {
return diff;
}
return Size + diff;
}
inline T& front() {
return buf_[tail_];
}
inline bool peek(T &item) {
return get(item, false);
}
};