#include	"sftest.h"

/*	Test for /dev/null and hole-preserving code */

MAIN()
{
	Sfio_t*	null;
	Sfio_t*	f;
	char	buf[256*1024], b[256*1024];
	int	k, n;

	if(!(null = sfopen(NIL(Sfio_t*),"/dev/null","w")) )
		terror("Opening /dev/null");

	sfsetbuf(null,NIL(char*),(size_t)SF_UNBOUND);

	if(!(f = sfopen(NIL(Sfio_t*), tstfile(0), "w+")) )
		terror("Creating %s", tstfile(0));
	sfwrite(f,"1234",4);
	sfseek(f,(Sfoff_t)1,0);
	sfsync(f);

	sfsetfd(null,-1);
	sfsetfd(null,sffileno(f));
	sfsync(null);

	sfseek(f,(Sfoff_t)0,0);
	if(sfread(f,buf,4) != 4 || strncmp(buf,"1234",4) != 0)
		terror("Bad data");

	for(k = 0; k < sizeof(buf); ++k)
		buf[k] = 1;
	for(k = sizeof(buf)/4; k < sizeof(buf)/2; ++k) /* make a big hole */
		buf[k] = 0;

	if(!(f = sfopen(f, tstfile(0), "w+")) )
		terror("Creating %s", tstfile(0));
	n = sizeof(buf)-127;
	if(sfwrite(f,buf,n) != n)
		terror("Writing large buffer");
	sfseek(f,(Sfoff_t)0,0);
	if(sfread(f,b,n) != n)
		terror("Reading large buffer");
	for(k = 0; k < n; ++k)
		if(b[k] != buf[k])
			terror("Bad data");

	TSTRETURN(0);
}