/* * cf. cmp <{dd -if data -bs 64k -count 20000} <{dd -if ../sda1/data -bs 64k -count 20000} * copyright © 2009 erik quanstrom */#include <u.h>#include <libc.h>#include <bio.h>#include <thread.h>#include <libsec.h> enum {	Stack	= 64*1024,	Block	= 64*1024,	Buffer	= 3, 	Memcmp= 1<<0,	Sha1	= 1<<1, 	Ferror	= 1<<1,	Fcmp	= 1<<2,	Fend	= 1<<3,}; typedef struct Ddargs Ddargs;struct Ddargs {	int	fd;	Channel	*c;	ulong	bs;	uvlong	start;	uvlong	end;}; typedef struct Bargs Bargs;struct Bargs {	uvlong	nblocks;	ulong	bs;	int	nend;}; typedef struct Msgbuf Msgbuf;struct Msgbuf {	uint	flags;	uvlong	lba;	char	status[ERRMAX];	uchar	data[Block];}; Channel	*blockfree;Channel	*blockalloc;Biobuf	out; voidblockproc(void *a){	uint h, t, f, e, c, m;	uvlong i;	Bargs *args;	Msgbuf *s, *r, **tab;	static Alt alts[3]; 	threadsetname("blockproc"); 	alts[0].c = blockalloc;	alts[0].v = &s;	alts[0].op = CHANSND;	alts[1].c = blockfree;	alts[1].v = &r;	alts[1].op = CHANRCV;	alts[2].op = CHANEND; 	args = (Bargs*)a;	tab = malloc(args->nblocks * sizeof tab[0]);	m = args->nblocks - 1;	if(tab == nil)		sysfatal("malloc: %r");	for(i = 0; i < args->nblocks; i++){		tab[i] = malloc(sizeof(Msgbuf));		if(tab[i] == nil)			sysfatal("malloc: %r");	}	h = t = 0;	e = c = 0;	s = nil;	for(f = args->nend; f > 0;){		if(s == nil){			s = tab[h % m];			if(s != nil){				tab[h++ % m] = nil;				alts[0].op = CHANSND;			}else				alts[0].op = CHANNOP;		}		switch(alt(alts)){		case 0:			s = nil;			break;		case 1:			assert(r != nil && tab[t % m] == nil);			tab[t++ % m] = r;			if(r->flags & Fend)				f--;			if(r->flags & Fcmp)				c++;			if(r->flags & Ferror)				e++;			r = nil;			break;		}	}	for(i = 0; i < args->nblocks; i++)		free(tab[i]);	free(tab);	if(e > 0)		threadexitsall("errors");	if(c > 0)		threadexitsall("cmp");	threadexitsall("");} Msgbuf*bufalloc(void){	Msgbuf *b; 	b = recvp(blockalloc);	if(b == nil)		sysfatal("recvp: %r");	b->flags = 0;	b->lba = 0;	b->status[0] = 0;	return b;} static intpreadn(int fd, void *av, long n, vlong o){	char *a;	long m, t; 	a = av;	t = 0;	while(t < n){		m = pread(fd, a+t, n-t, o+t);		if(m <= 0){			if(t == 0)				return m;			break;		}		t += m;	}	return t;} voidddproc(void *a){	int rv;	uvlong i;	Ddargs *d;	Msgbuf *b; 	threadsetname("ddproc");	d = (Ddargs*)a;	for(i = d->start; i < d->end; i++){		b = bufalloc();		b->lba = i;		rv = preadn(d->fd, b->data, d->bs, b->lba * d->bs);		if(rv != d->bs){			errstr(b->status, sizeof b->status);			b->flags |= Ferror;		}		sendp(d->c, b);	}	close(d->fd); 	b = bufalloc();	b->flags |= Fend;	sendp(d->c, b);	threadexits("");} static intAfmt(Fmt *f){	char buf[SHA1dlen*2 + 1];	uchar *u, i; 	u = va_arg(f->args, uchar*);	if(u == 0 && f->flags & FmtSharp)		return fmtstrcpy(f, "-");	if(u == 0)		return fmtstrcpy(f, "<nildigest>");	for(i = 0; i < SHA1dlen; i++)		sprint(buf + 2*i, "%2.2ux", u[i]);	return fmtstrcpy(f, buf);}#pragma	varargck	type	"A"	uchar* uint	bs		= Block;uint	cmptype		= Memcmp;Channel *dev[2];QLock	cmplock;int	pflag; intdocmp(Msgbuf **b){	uchar suma[SHA1dlen], sumb[SHA1dlen], *x, *y;	uint i;	uvlong lba; 	x = b[0]->data;	y = b[1]->data; 	switch(cmptype){	case Memcmp:		if(memcmp(x, y, bs) != 0){			lba = b[0]->lba;			for(i = 0; i < bs; i++)				if(x[i] != y[i])					break;			Bprint(&out, "%llud + %ud\n", lba, i);			return 1;		}		return 0;	case Sha1:fprint(2, "sha1\n");abort();fprint(2, "  sha1\n");		sha1(x, bs, suma, nil);fprint(2, "b\n");		sha1(y, bs, sumb, nil);fprint(2, "sha1\n");		if(memcmp(suma, sumb, sizeof suma) != 0){fprint(2, "cmp! %A %A\n", suma, sumb);			Bprint(&out, "%A %A\n", suma, sumb);			return 1;		}fprint(2, "cmp %A %A\n", suma, sumb);		return 0;	default:		abort();		return -1;	}} voidcmpproc(void*){	int i, end;	Msgbuf *b[2]; 	threadsetname("cmpproc");	for(;;){		qlock(&cmplock);		for(i = 0; i < 2; i++)			b[i] = recvp(dev[i]);		qunlock(&cmplock);		assert(b[0] != nil && b[1] != nil);		assert(b[0]->lba == b[1]->lba);		end = b[0]->flags & Fend; 		if(b[0]->flags & Ferror)			fprint(2, "cmp error: %llud: device 0 error: %s\n",				b[0]->lba, b[0]->status);		else if(b[0]->flags & Ferror)			fprint(2, "cmp error: %llud: device 1 error: %s\n",				b[1]->lba, b[1]->status);		else if(!end && docmp(b))			b[0]->flags |= Fcmp;		sendp(blockfree, b[0]);		sendp(blockfree, b[1]);		if(end)			break;	}	threadexits("");} voidusage(void){	fprint(2, "usage: disk/cmp [-n nblocks] [-b blocksz] dev0 dev1\n");	threadexitsall("usage");} Ddargs d[2];Bargs a; voidthreadmain(int argc, char **argv){	int i;	uvlong nblocks;	Dir *e; 	nblocks = 0;	ARGBEGIN{	case 'n':		nblocks = atoi(EARGF(usage()));		break;	case 'b':		bs = atoi(EARGF(usage()));		break;	case 's':		cmptype = Sha1;		break;	case 'p':		pflag = 1;		break;	default:		usage();	}ARGEND	if(argc != 2)		usage();	fmtinstall('A', Afmt);	Binit(&out, 1, OWRITE); 	for(i = 0; i < 2; i++){		d[i].fd = open(argv[i], OREAD);		if(d[i].fd == -1)			sysfatal("open: %r");		d[i].bs = bs;		d[i].start = 0;		if(nblocks != 0)			d[i].end = nblocks;		else{			e = dirfstat(d[i].fd);			if(e == nil)				sysfatal("dirfstat: %r");			d[i].end = e->length / d[i].bs;			free(e);		}		d[i].c = dev[i] = chancreate(sizeof(Msgbuf*), Buffer);		if(d[i].c == nil)			sysfatal("chancreate: %r");	}	blockfree = chancreate(sizeof(Msgbuf*), 1);	blockalloc = chancreate(sizeof(Msgbuf*), 1);	if(blockalloc == nil || blockfree == nil)		sysfatal("chancreate: %r");	a.nblocks = 2*Buffer;	a.bs = bs;	a.nend = 2;	proccreate(ddproc, d + 0, Stack);	proccreate(ddproc, d + 1, Stack);	for(i = 0; i < 4; i++)		proccreate(cmpproc, nil, Stack);	blockproc(&a);	threadexitsall("");}