712476cd28
This implements some helper functions that allow sending key reports to an SPI based Bluetooth Low Energy module, such as the Adafruit Feather 32u4 Bluefruit LE. There is some plumbing required in lufa.c to enable this; that is in a follow-on commit.
67 lines
1.2 KiB
C++
67 lines
1.2 KiB
C++
#pragma once
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// A simple ringbuffer holding Size elements of type T
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template <typename T, uint8_t Size>
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class RingBuffer {
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protected:
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T buf_[Size];
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uint8_t head_{0}, tail_{0};
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public:
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inline uint8_t nextPosition(uint8_t position) {
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return (position + 1) % Size;
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}
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inline uint8_t prevPosition(uint8_t position) {
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if (position == 0) {
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return Size - 1;
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}
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return position - 1;
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}
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inline bool enqueue(const T &item) {
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static_assert(Size > 1, "RingBuffer size must be > 1");
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uint8_t next = nextPosition(head_);
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if (next == tail_) {
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// Full
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return false;
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}
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buf_[head_] = item;
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head_ = next;
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return true;
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}
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inline bool get(T &dest, bool commit = true) {
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auto tail = tail_;
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if (tail == head_) {
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// No more data
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return false;
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}
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dest = buf_[tail];
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tail = nextPosition(tail);
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if (commit) {
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tail_ = tail;
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}
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return true;
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}
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inline bool empty() const { return head_ == tail_; }
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inline uint8_t size() const {
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int diff = head_ - tail_;
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if (diff >= 0) {
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return diff;
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}
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return Size + diff;
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}
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inline T& front() {
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return buf_[tail_];
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}
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inline bool peek(T &item) {
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return get(item, false);
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}
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};
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