/**
 * \file
 * <!--
 * This file is part of BeRTOS.
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 * it under the terms of the GNU General Public License as published by
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 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
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 * Copyright 2009 Develer S.r.l. (http://www.develer.com/)
 *
 * -->
 *
 * \brief KFile interface over a memory buffer.
 *
 * \author Francesco Sacchi <batt@develer.com>
 */

#include "kfile_mem.h"

#include <io/kfile.h>

#include <string.h>

static size_t kfilemem_read(struct KFile *_fd, void *buf, size_t size)
{
	KFileMem *fd = KFILEMEM_CAST(_fd);

	size = MIN((kfile_off_t)size, fd->fd.size - fd->fd.seek_pos);
	uint8_t *mem = (uint8_t *)fd->mem;
	memcpy(buf, mem + fd->fd.seek_pos, size);
	fd->fd.seek_pos += size;

	return size;
}

static size_t kfilemem_write(struct KFile *_fd, const void *buf, size_t size)
{
	KFileMem *fd = KFILEMEM_CAST(_fd);

	size = MIN((kfile_off_t)size, fd->fd.size - fd->fd.seek_pos);
	uint8_t *mem = (uint8_t *)fd->mem;
	memcpy(mem + fd->fd.seek_pos, buf, size);
	fd->fd.seek_pos += size;

	return size;
}

void kfilemem_init(KFileMem *km, void *mem, size_t len)
{
	ASSERT(km);
	ASSERT(mem);
	ASSERT(len);

	memset(km, 0, sizeof(*km));

	km->mem = mem;
	kfile_init(&km->fd);
	km->fd.read = kfilemem_read;
	km->fd.write = kfilemem_write;
	km->fd.size = len;
	DB(km->fd._type = KFT_KFILEMEM);
}