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#include	<u.h>
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#include	<libc.h>
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int	ulcmp(void*, void*);
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void	swapem(ulong*, long);
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enum
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{
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	Wormsize	= 157933,
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};
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int	wflag;
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void
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main(int argc, char *argv[])
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{
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	long i, l, x, lobits, hibits, tot;
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	int f, j;
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	char *file;
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	ulong *b, a, lo, hi;
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	ARGBEGIN {
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	default:
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		print("usage: disk/exsort [-w] [file]\n");
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		exits("usage");
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	case 'w':
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		wflag++;
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		break;
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	} ARGEND;
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	file = "/adm/cache";
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	if(argc > 0)
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		file = argv[0];
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	if(wflag)
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		f = open(file, ORDWR);
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	else
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		f = open(file, OREAD);
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	if(f < 0) {
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		print("cant open %s: %r\n", file);
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		exits("open");
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	}
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	l = seek(f, 0, 2) / sizeof(long);
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	b = malloc(l*sizeof(long));
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	if(b == 0) {
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		print("cant malloc %s: %r\n", file);
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		exits("malloc");
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	}
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	seek(f, 0, 0);
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	if(read(f, b, l*sizeof(long)) != l*sizeof(long)) {
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		print("short read %s: %r\n", file);
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		exits("read");
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	}
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	lobits = 0;
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	hibits = 0;
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	for(i=0; i<l; i++) {
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		a = b[i];
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		if(a & (1L<<7))
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			lobits++;
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		if(a & (1L<<31))
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			hibits++;
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	}
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	print("lobits = %6ld\n", lobits);
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	print("hibits = %6ld\n", hibits);
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	if(hibits > lobits) {
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		print("swapping\n");
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		swapem(b, l);
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	}
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	qsort(b, l, sizeof(ulong), ulcmp);
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	tot = 0;
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	for(j=0; j<100; j++) {
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		lo = j*Wormsize;
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		hi = lo + Wormsize;
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		x = 0;
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		for(i=0; i<l; i++) {
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			a = b[i];
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			if(a >= lo && a < hi)
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				x++;
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		}
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		if(x) {
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			print("disk %2d %6ld blocks\n", j, x);
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			tot += x;
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		}
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	}
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	print("total   %6ld blocks\n", tot);
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	if(wflag) {
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		if(hibits > lobits)
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			swapem(b, l);
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		seek(f, 0, 0);
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		if(write(f, b, l*sizeof(long)) != l*sizeof(long)) {
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			print("short write %s\n", file);
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			exits("write");
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		}
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	}
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	exits(0);
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}
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int
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ulcmp(void *va, void *vb)
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{
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	ulong *a, *b;
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	a = va;
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	b = vb;
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	if(*a > *b)
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		return 1;
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	if(*a < *b)
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		return -1;
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	return 0;
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}
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void
123 
swapem(ulong *b, long l)
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{
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	long i;
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	ulong x, a;
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128 
	for(i=0; i<l; i++, b++) {
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		a = *b;
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		x = (((a>>0) & 0xff) << 24) |
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			(((a>>8) & 0xff) << 16) |
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			(((a>>16) & 0xff) << 8) |
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			(((a>>24) & 0xff) << 0);
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		*b = x;
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	}
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}