82 lines
2.1 KiB
C++
82 lines
2.1 KiB
C++
#ifndef RINGBUFFER_H
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#define RINGBUFFER_H
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#include <cstddef>
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#include <iostream>
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#include <vector>
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#include <atomic>
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#include <algorithm>
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#include <cstdint>
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#include <type_traits>
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template<typename T>
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class RingBuffer {
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public:
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explicit RingBuffer(size_t capacity, T initValue = T{})
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: m_capacity(capacity)
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, m_data(capacity, initValue) {}
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inline void push(const T& v) {
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const uint64_t w = m_write.fetch_add(1, std::memory_order_relaxed);
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m_data[w % m_capacity] = v;
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const uint64_t newSize = std::min<uint64_t>(w + 1, m_capacity);
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m_size.store(newSize, std::memory_order_release);
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}
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inline uint64_t size() const {
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return m_size.load(std::memory_order_acquire);
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}
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inline uint64_t capacity() const {
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return m_capacity;
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}
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inline uint64_t oldestGlobalIndex() const {
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const uint64_t w = m_write.load(std::memory_order_acquire);
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const uint64_t s = size();
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return (w >= s) ? (w - s) : 0;
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}
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inline uint64_t newestGlobalIndex() const {
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const uint64_t w = m_write.load(std::memory_order_acquire);
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return (w > 0) ? (w - 1) : 0;
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}
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inline bool readByGlobalIndex(uint64_t gidx, T& out) const {
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const uint64_t oldest = oldestGlobalIndex();
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const uint64_t newest = newestGlobalIndex();
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if (gidx < oldest || gidx > newest)
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return false;
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out = m_data[gidx % m_capacity];
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return true;
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}
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inline void reset() {
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m_write.store(0, std::memory_order_release);
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m_size.store(0, std::memory_order_release);
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}
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inline void readRange(uint64_t gidx, uint64_t count, std::vector<T>& out) const {
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out.clear();
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out.reserve(count);
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for (size_t i = 0; i < count; i++) {
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T v{};
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if (readByGlobalIndex(gidx, v)) {
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out.push_back(v);
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}
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else {
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}
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}
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}
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private:
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uint64_t m_capacity;
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std::vector<T> m_data;
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std::atomic<uint64_t> m_write{0};
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std::atomic<uint64_t> m_size{0};
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};
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#endif |