/*
 * $Id: stdio_fread.c,v 1.7 2006-01-08 12:04:24 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */

/****************************************************************************/

#ifndef _STDIO_HEADERS_H
#include "stdio_headers.h"
#endif /* _STDIO_HEADERS_H */

/****************************************************************************/

size_t
fread(void *ptr,size_t element_size,size_t count,FILE *stream)
{
	struct iob * file = (struct iob *)stream;
	size_t result = 0;

	ENTER();

	SHOWPOINTER(ptr);
	SHOWVALUE(element_size);
	SHOWVALUE(count);
	SHOWPOINTER(stream);

	assert( ptr != NULL && stream != NULL );
	assert( (int)element_size >= 0 && (int)count >= 0 );

	if(__check_abort_enabled)
		__check_abort();

	flockfile(stream);

	#if defined(CHECK_FOR_NULL_POINTERS)
	{
		if(ptr == NULL || stream == NULL)
		{
			SHOWMSG("invalid parameters");

			__set_errno(EFAULT);
			goto out;
		}
	}
	#endif /* CHECK_FOR_NULL_POINTERS */

	assert( __is_valid_iob(file) );
	assert( FLAG_IS_SET(file->iob_Flags,IOBF_IN_USE) );
	assert( file->iob_BufferSize > 0 );

	if(FLAG_IS_CLEAR(file->iob_Flags,IOBF_IN_USE))
	{
		SHOWMSG("this file is not even in use");

		SET_FLAG(file->iob_Flags,IOBF_ERROR);

		__set_errno(EBADF);

		goto out;
	}

	if(FLAG_IS_CLEAR(file->iob_Flags,IOBF_READ))
	{
		SHOWMSG("this file is not read-enabled");

		SET_FLAG(file->iob_Flags,IOBF_ERROR);

		__set_errno(EBADF);

		goto out;
	}

	if(element_size > 0 && count > 0)
	{
		size_t total_bytes_read = 0;
		size_t total_size;
		unsigned char * data = ptr;
		int c;

		if(__fgetc_check((FILE *)file) < 0)
			goto out;

		total_size = element_size * count;

		SHOWVALUE(total_size);

		while(total_size-- > 0)
		{
			c = __getc(file);
			if(c == EOF)
				break;

			(*data++) = c;

			total_bytes_read++;
		}

		SHOWVALUE(total_bytes_read);

		result = total_bytes_read / element_size;
	}
	else
	{
		SHOWVALUE(element_size);
		SHOWVALUE(count);

		SHOWMSG("either element size or count is zero");

		/* Don't let this appear like an EOF or error. */
		clearerr((FILE *)file);
	}

	D(("total number of elements read = %ld",result));

 out:

	funlockfile(stream);

	RETURN(result);
	return(result);
}