100 lines
2.1 KiB
C++
100 lines
2.1 KiB
C++
#pragma once
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#include <array>
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/**
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* A simple ring buffer structure
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*/
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template<typename T, int Size>
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struct Ringbuf {
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Ringbuf() : m_head(0), m_tail(0) {}
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/**
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* Clears the buffer's contents
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*/
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void clear() {
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m_head = 0;
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m_tail = 0;
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}
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/**
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* Returns the value of the next available item, if available
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*/
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T peek(int offset) const {
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const int nextHead = (m_head + offset) % Size;
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return m_items[nextHead];
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}
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/**
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* Removes and returns the next available item, if any.
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*
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* @return false if no data is available, true otherwise
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*/
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bool take(T& dest) {
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if (m_head == m_tail) {
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return false;
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}
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const int cur = m_head;
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const int nextHead = (m_head + 1) % Size;
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m_head = nextHead;
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dest = m_items[cur];
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return true;
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}
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/**
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* Inserts an item into the buffer. If the buffer is full, the oldest item
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* is overwritten.
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*/
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void insert(const T& src) {
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const int cur = m_tail;
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const int nextTail = (m_tail + 1) % Size;
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if (nextTail == m_head) {
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return;
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} else {
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m_tail = nextTail;
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}
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m_items[cur] = src;
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}
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/**
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* Consumes the entire buffer and writes it to the given array.
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*/
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size_t write(T(&dest)[Size]) {
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int i = 0;
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size_t ret = 0;
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while(take(dest[i])) {
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i++;
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ret += sizeof(T);
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}
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return ret;
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}
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/**
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* Consumes the entire buffer and writes it to the given output
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*/
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size_t write(Print& stream) {
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T val;
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size_t ret = 0;
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while(take(val)) {
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stream.write(val);
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}
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return ret;
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}
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/**
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* Returns how many items are available in the buffer
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*/
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size_t size() {
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if (m_tail > m_head) {
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return m_tail - m_head;
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} else if (m_tail == m_head) {
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return 0;
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}
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return m_tail + (Size - m_head);
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}
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private:
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int m_head = 0;
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int m_tail = 0;
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std::array<T, Size> m_items;
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};
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