69 lines
1.4 KiB
C
69 lines
1.4 KiB
C
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// SPDX-License-Identifier: MIT
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/**
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Copyright (c) 2015 - 2022 Beckhoff Automation GmbH & Co. KG
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*/
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#pragma once
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#include <cassert>
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#include <cstdint>
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#include <memory>
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struct RingBuffer {
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RingBuffer(size_t N)
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: dataSize(N + 1),
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data(new uint8_t[N + 1]),
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write(data.get()),
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read(data.get())
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{}
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size_t BytesFree() const
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{
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return (write < read) ? read - write - 1 : dataSize - 1 - (write - read);
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}
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size_t BytesAvailable() const
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{
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return dataSize - BytesFree() - 1;
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}
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size_t WriteChunk() const
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{
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return (write < read) ? read - write - 1 : data.get() + dataSize - write - (data.get() == read);
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}
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void Write(size_t n)
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{
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assert(n <= BytesFree());
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write = Increment(write, n);
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}
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template<class T> T ReadFromLittleEndian()
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{
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T result = 0;
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for (size_t i = 0; i < sizeof(T); ++i) {
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result += (((T)(*read)) << (8 * i));
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read = Increment(read, 1);
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}
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return result;
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}
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void Read(size_t n)
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{
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assert(n <= BytesAvailable());
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read = Increment(read, n);
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}
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private:
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const size_t dataSize;
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const std::unique_ptr<uint8_t[]> data;
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inline uint8_t* Increment(const uint8_t* ptr, size_t n)
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{
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return data.get() + ((ptr - data.get() + n) % dataSize);
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}
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public:
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uint8_t* write;
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const uint8_t* read;
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};
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