Kernel/library/cbuf.cpp

/*
	This file is part of Fennix Kernel.

	Fennix Kernel is free software: you can redistribute it and/or
	modify it under the terms of the GNU General Public License as
	published by the Free Software Foundation, either version 3 of
	the License, or (at your option) any later version.

	Fennix Kernel is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#include <cbuf.hpp>

CircularBuffer::CircularBuffer(size_t Size)
	: Buffer(new uint8_t[Size]),
	  BufferSize(Size),
	  BufferCount(0),
	  Head(0),
	  Tail(0) {}

CircularBuffer::~CircularBuffer() { delete[] Buffer; }

size_t CircularBuffer::Write(const uint8_t *Data, size_t Size)
{
	sl_guard(Lock);

	size_t written = 0;
	while (Size > 0)
	{
		if (BufferCount == BufferSize)
			break;

		Buffer[Head] = *Data++;
		Head = (Head + 1) % BufferSize;
		BufferCount++;
		written++;
		Size--;
	}

	return written;
}

size_t CircularBuffer::Read(uint8_t *Data, size_t Size)
{
	sl_guard(Lock);

	size_t read = 0;
	while (Size > 0)
	{
		if (BufferCount == 0)
			break;

		*Data++ = Buffer[Tail];
		Tail = (Tail + 1) % BufferSize;
		BufferCount--;
		read++;
		Size--;
	}

	return read;
}

size_t CircularBuffer::Peek(uint8_t *Data, size_t Size)
{
	sl_guard(Lock);

	size_t read = 0;
	size_t tail = Tail;
	while (Size > 0)
	{
		if (read == BufferCount)
			break;

		*Data++ = Buffer[tail];
		tail = (tail + 1) % BufferSize;
		read++;
		Size--;
	}

	return read;
}

size_t CircularBuffer::Count()
{
	sl_guard(Lock);
	return BufferCount;
}

size_t CircularBuffer::Free()
{
	sl_guard(Lock);
	return BufferSize - BufferCount;
}