/**
 * Compile command : gcc gfal_testrw.c `pkg-config --libs --cflags gfal2`
 */


#include <fcntl.h>
#include <stdio.h>
#include <gfal_api.h>
#include <stdlib.h>
#define BLKLEN 65536

main(int argc, char **argv)
{
   int fd;
   int i;
   char ibuf[BLKLEN];
   char obuf[BLKLEN];
   int rc;

   // gfal_set_verbose(GFAL_VERBOSE_TRACE | GFAL_VERBOSE_VERBOSE);	// switch Gfal in verbose mode
   if (argc != 2) {
	   fprintf (stderr, "usage: %s filename\n", argv[0]);
	   exit (1);
   }

   for (i = 0; i < BLKLEN; i++)
	   obuf[i] = i;

   printf ("creating file %s\n", argv[1]);
   if ((fd = gfal_open (argv[1], O_WRONLY|O_CREAT, 0644)) < 0) {
		gfal_posix_check_error();
		exit (1);
   }
   
	printf ("open successful, fd = %d\n", fd);

	if ((rc = gfal_write (fd, obuf, BLKLEN)) != BLKLEN) {
		gfal_posix_check_error();
		(void) gfal_close (fd);
		exit (1);
	}
	printf ("write successful\n");

	if ((rc = gfal_close (fd)) < 0) {
		gfal_posix_check_error();
		exit (1);
	}
	printf ("close successful\n");


	printf ("reading back %s\n", argv[1]);
	if ((fd = gfal_open (argv[1], O_RDONLY, 0)) < 0) {
		gfal_posix_check_error();
		exit (1);
	}
	printf ("open successful, fd = %d\n", fd);

	if ((rc = gfal_read (fd, ibuf, BLKLEN)) != BLKLEN) {
			gfal_posix_check_error();
			(void) gfal_close (fd);
			exit (1);
	   }
	   printf ("read successful\n");

	   if ((rc = gfal_close (fd)) < 0) {
			gfal_posix_check_error();
			exit (1);
	   }
	   printf ("close successful\n");

	   for (i = 0; i < BLKLEN; i++) {
		   if (ibuf[i] != obuf[i]) {
				fprintf (stderr, "compare failed at offset %d\n", i);
				exit (1);
		   }
	   }
	   printf ("compare successful\n");
	   exit (0);
}