/*
   Copyright (C) 2006-2011 Con Kolivas
   Copyright (C) 2008, 2011 Peter Hyman
   Copyright (C) 1998 Andrew Tridgell

   This program 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 2 of the License, or
   (at your option) any later version.

   This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/

/*
  Utilities used in rzip

  tridge, June 1996
  */

/*
 * Realloc removed
 * Functions added
 *    read_config()
 * Peter Hyman, December 2008
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdarg.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#ifdef _SC_PAGE_SIZE
# define PAGE_SIZE (sysconf(_SC_PAGE_SIZE))
#else
# define PAGE_SIZE (4096)
#endif

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "lrzip_private.h"
#include "liblrzip.h"

static const char *infile = NULL;
static char delete_infile = 0;
static const char *outfile = NULL;
static char delete_outfile = 0;
static FILE *outputfile = NULL;

void register_infile(const char *name, char delete)
{
	infile = name;
	delete_infile = delete;
}

void register_outfile(const char *name, char delete)
{
	outfile = name;
	delete_outfile = delete;
}

void register_outputfile(FILE *f)
{
	outputfile = f;
}

void unlink_files(void)
{
	/* Delete temporary files generated for testing or faking stdio */
	if (outfile && delete_outfile)
		unlink(outfile);

	if (infile && delete_infile)
		unlink(infile);
}

static void fatal_exit(void)
{
	unlink_files();
	fprintf(outputfile, "Fatal error - exiting\n");
	fflush(outputfile);
	exit(1);
}

/* Failure when there is likely to be a meaningful error in perror */
void fatal(const char *format, ...)
{
	va_list ap;

	if (format) {
		va_start(ap, format);
		vfprintf(stderr, format, ap);
		va_end(ap);
	}

	perror(NULL);
	fatal_exit();
}

void failure(const char *format, ...)
{
	va_list ap;

	if (format) {
		va_start(ap, format);
		vfprintf(stderr, format, ap);
		va_end(ap);
	}

	fatal_exit();
}

void round_to_page(i64 *size)
{
	*size -= *size % PAGE_SIZE;
	if (unlikely(!*size))
		*size = PAGE_SIZE;
}

void get_rand(uchar *buf, int len)
{
	int fd, i;

	fd = open("/dev/urandom", O_RDONLY);
	if (fd == -1) {
		for (i = 0; i < len; i++)
			buf[i] = (uchar)random();
	} else {
		if (unlikely(read(fd, buf, len) != len))
			fatal("Failed to read fd in get_rand\n");
		if (unlikely(close(fd)))
			fatal("Failed to close fd in get_rand\n");
	}
}