From 48976fff88b05c2eda807337f0d6a8b0aaf8fa39 Mon Sep 17 00:00:00 2001
From: Henrik Stickann <4376396-Mithradir@users.noreply.gitlab.com>
Date: Wed, 27 Apr 2022 18:34:42 +0200
Subject: [PATCH] Add FIFO buffer type

---
 include/sta/fifo_buffer.hpp |  97 +++++++++++++++++++++++++++++++++
 include/sta/fifo_buffer.tpp | 103 ++++++++++++++++++++++++++++++++++++
 2 files changed, 200 insertions(+)
 create mode 100644 include/sta/fifo_buffer.hpp
 create mode 100644 include/sta/fifo_buffer.tpp

diff --git a/include/sta/fifo_buffer.hpp b/include/sta/fifo_buffer.hpp
new file mode 100644
index 0000000..b0db3a8
--- /dev/null
+++ b/include/sta/fifo_buffer.hpp
@@ -0,0 +1,97 @@
+#ifndef STA_FIFO_BUFFER_HPP
+#define STA_FIFO_BUFFER_HPP
+
+
+namespace sta
+{
+	/**
+	 * @brief FIFO buffer.
+	 *
+	 * @tparam Size     Size type
+	 * @tparam N        Buffer size
+	 */
+	template <typename Size, Size N>
+	class FifoBuffer
+	{
+	public:
+		using size_type = Size;
+		static constexpr size_type MAX_SIZE = N;
+
+	public:
+		FifoBuffer();
+		FifoBuffer(const uint8_t * buffer, Size size);
+
+		/**
+		 * @brief Clear buffer content.
+		 */
+		void clear();
+
+		/**
+		 * @brief Set data in buffer.
+		 *
+		 * @param buffer    Source buffer
+		 * @param size      Number of bytes to write
+		 */
+		void set(const uint8_t * buffer, size_type size);
+
+		/**
+		 * @brief Append value to end of buffer.
+		 *
+		 * @param value     Value
+		 */
+		void pushBack(uint8_t value);
+		/**
+		 * @brief Append data to end of buffer.
+		 *
+		 * @param buffer    Source buffer
+		 * @param size      Number of bytes to write
+		 */
+		void pushBack(const uint8_t * buffer, size_type size);
+		/**
+		 * @brief Append value repeatedly to end of buffer.
+		 *
+		 * @param value     Fill value
+		 * @param count     Repeat count
+		 */
+		void pushBack(uint8_t value, size_type count);
+
+		/**
+		 * @brief Take data from start of buffer.
+		 *
+		 * @param buffer    Destination buffer
+		 * @param size      Number of bytes to read
+		 */
+		void popFront(uint8_t * buffer, size_type size);
+
+		/**
+		 * @brief Get size of data in buffer.
+		 *
+		 * @return  Data size
+		 */
+		size_type size() const;
+
+		/**
+		 * @brief Check if buffer is full.
+		 *
+		 * @return  True if buffer is full
+		 */
+		bool isFull() const;
+		/**
+		 * @brief Check if buffer is empty.
+		 *
+		 * @return  True if buffer is empty
+		 */
+		bool isEmpty() const;
+
+	private:
+		uint8_t * head_;        /**< Read position */
+		uint8_t * tail_;        /**< Write position */
+		uint8_t   buffer_[N];   /**< Buffer data */
+	};
+} // namespace sta
+
+
+#include <sta/fifo_buffer.tpp>
+
+
+#endif // STA_FIFO_BUFFER_HPP
diff --git a/include/sta/fifo_buffer.tpp b/include/sta/fifo_buffer.tpp
new file mode 100644
index 0000000..b593d53
--- /dev/null
+++ b/include/sta/fifo_buffer.tpp
@@ -0,0 +1,103 @@
+#ifndef STA_FIFO_BUFFER_TPP
+#define STA_FIFO_BUFFER_TPP
+
+#ifndef STA_FIFO_BUFFER_HPP
+#  error "Internal header. Include <sta/fifo_buffer.hpp> instead"
+#endif // !STA_FIFO_BUFFER_HPP
+
+#include <cstring>
+
+
+namespace sta
+{
+	template <typename Size, Size N>
+	FifoBuffer<Size, N>::FifoBuffer()
+		: head_{buffer_}, tail_{buffer_}
+	{}
+
+	template <typename Size, Size N>
+	FifoBuffer<Size, N>::FifoBuffer(const uint8_t * buffer, size_type size)
+	{
+		set(buffer, size);
+	}
+
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::set(const uint8_t * buffer, size_type bsize)
+	{
+		STA_ASSERT(bsize <= sizeof(buffer_));
+		STA_ASSERT(buffer != nullptr);
+
+		head_ = buffer_;
+		tail_ = buffer_ + bsize;
+		memcpy(buffer_, buffer, bsize);
+	}
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::clear()
+	{
+		head_ = tail_ = buffer_;
+	}
+
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::pushBack(uint8_t value)
+	{
+		STA_ASSERT_MSG(tail_ < buffer_ + sizeof(buffer_), "Buffer overflow");
+
+		*tail_++ = value;
+	}
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::pushBack(const uint8_t * buffer, size_type bsize)
+	{
+		STA_ASSERT_MSG(size() + bsize <= sizeof(buffer_), "Buffer overflow");
+		STA_ASSERT(buffer != nullptr);
+
+		memcpy(tail_, buffer, bsize);
+		tail_ += bsize;
+	}
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::pushBack(uint8_t value, size_type count)
+	{
+		STA_ASSERT_MSG(size() + count <= sizeof(buffer_), "Buffer overflow");
+
+		memset(tail_, value, count);
+		tail_ += count;
+	}
+
+
+	template <typename Size, Size N>
+	void FifoBuffer<Size, N>::popFront(uint8_t * buffer, size_type bsize)
+	{
+		STA_ASSERT_MSG(size() >= bsize, "Not enough data");
+		STA_ASSERT(buffer != nullptr);
+
+		memcpy(buffer, head_, bsize);
+		head_ += bsize;
+	}
+
+
+	template <typename Size, Size N>
+	typename FifoBuffer<Size, N>::size_type FifoBuffer<Size, N>::size() const
+	{
+		return (tail_ - head_);
+	}
+
+
+	template <typename Size, Size N>
+	bool FifoBuffer<Size, N>::isFull() const
+	{
+		return (tail_ == buffer_ + sizeof(buffer_));
+	}
+
+	template <typename Size, Size N>
+	bool FifoBuffer<Size, N>::isEmpty() const
+	{
+		return (head_ == tail_);
+	}
+} // namespace sta
+
+
+#endif // STA_FIFO_BUFFER_TPP