henesyinit from p9fd787fda5 years agoHistory
136 lines · 1.9 KB · C
RawDownload
#include	<u.h>#include	<libc.h> int	ulcmp(void*, void*);void	swapem(ulong*, long); enum{	Wormsize	= 157933,};int	wflag; voidmain(int argc, char *argv[]){	long i, l, x, lobits, hibits, tot;	int f, j;	char *file;	ulong *b, a, lo, hi; 	ARGBEGIN {	default:		print("usage: disk/exsort [-w] [file]\n");		exits("usage");	case 'w':		wflag++;		break;	} ARGEND; 	file = "/adm/cache";	if(argc > 0)		file = argv[0]; 	if(wflag)		f = open(file, ORDWR);	else		f = open(file, OREAD);	if(f < 0) {		print("cant open %s: %r\n", file);		exits("open");	}	l = seek(f, 0, 2) / sizeof(long); 	b = malloc(l*sizeof(long));	if(b == 0) {		print("cant malloc %s: %r\n", file);		exits("malloc");	}	seek(f, 0, 0);	if(read(f, b, l*sizeof(long)) != l*sizeof(long)) {		print("short read %s: %r\n", file);		exits("read");	} 	lobits = 0;	hibits = 0;	for(i=0; i<l; i++) {		a = b[i];		if(a & (1L<<7))			lobits++;		if(a & (1L<<31))			hibits++;	} 	print("lobits = %6ld\n", lobits);	print("hibits = %6ld\n", hibits); 	if(hibits > lobits) {		print("swapping\n");		swapem(b, l);	} 	qsort(b, l, sizeof(ulong), ulcmp); 	tot = 0;	for(j=0; j<100; j++) {		lo = j*Wormsize;		hi = lo + Wormsize; 		x = 0;		for(i=0; i<l; i++) {			a = b[i];			if(a >= lo && a < hi)				x++;		}		if(x) {			print("disk %2d %6ld blocks\n", j, x);			tot += x;		}	}	print("total   %6ld blocks\n", tot);  	if(wflag) {		if(hibits > lobits)			swapem(b, l);		seek(f, 0, 0);		if(write(f, b, l*sizeof(long)) != l*sizeof(long)) {			print("short write %s\n", file);			exits("write");		}	} 	exits(0);} intulcmp(void *va, void *vb){	ulong *a, *b; 	a = va;	b = vb; 	if(*a > *b)		return 1;	if(*a < *b)		return -1;	return 0;} voidswapem(ulong *b, long l){	long i;	ulong x, a; 	for(i=0; i<l; i++, b++) {		a = *b;		x = (((a>>0) & 0xff) << 24) |			(((a>>8) & 0xff) << 16) |			(((a>>16) & 0xff) << 8) |			(((a>>24) & 0xff) << 0);		*b = x;	}}