xfid.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

				if(w->nomark == FALSE){
					seq++;
					filemark(t->file);
				}
				q0 = textbsinsert(t, q0, r, nr, TRUE, &nr);
				textsetselect(t, t->q0, t->q1);	/* insert could leave it somewhere else */
				if(qid!=QWwrsel && !t->w->noscroll)
					textshow(t, q0+nr, q0+nr, 1);
				textscrdraw(t);
			}
			winsettag(w);
			if(qid == QWwrsel)
				w->wrselrange.q1 += nr;
			free(r);
		}
		fc.count = x->count;
		respond(x, &fc, nil);
		break;

	default:
		sprint(buf, "unknown qid %d in write", qid);
		respond(x, &fc, buf);
		break;
	}
	if(w)
		winunlock(w);
}

void
xfidctlwrite(Xfid *x, Window *w)
{
	Fcall fc;
	int i, m, n, nb, nr, nulls;
	Rune *r;
	char *err, *p, *pp, *q, *e;
	int isfbuf, scrdraw, settag;
	Text *t;

	err = nil;
	e = x->data+x->count;
	scrdraw = FALSE;
	settag = FALSE;
	isfbuf = TRUE;
	if(x->count < RBUFSIZE)
		r = fbufalloc();
	else{
		isfbuf = FALSE;
		r = emalloc(x->count*UTFmax+1);
	}
	x->data[x->count] = 0;
	textcommit(&w->tag, TRUE);
	for(n=0; n<x->count; n+=m){
		p = x->data+n;
		if(strncmp(p, "lock", 4) == 0){	/* make window exclusive use */
			qlock(&w->ctllock);
			w->ctlfid = x->f->fid;
			m = 4;
		}else
		if(strncmp(p, "unlock", 6) == 0){	/* release exclusive use */
			w->ctlfid = ~0;
			qunlock(&w->ctllock);
			m = 6;
		}else
		if(strncmp(p, "clean", 5) == 0){	/* mark window 'clean', seq=0 */
			t = &w->body;
			t->eq0 = ~0;
			filereset(t->file);
			t->file->mod = FALSE;
			w->dirty = FALSE;
			settag = TRUE;
			m = 5;
		}else
		if(strncmp(p, "dirty", 5) == 0){	/* mark window 'dirty' */
			t = &w->body;
			/* doesn't change sequence number, so "Put" won't appear.  it shouldn't. */
			t->file->mod = TRUE;
			w->dirty = TRUE;
			settag = TRUE;
			m = 5;
		}else
		if(strncmp(p, "show", 4) == 0){	/* show dot */
			t = &w->body;
			textshow(t, t->q0, t->q1, 1);
			m = 4;
		}else
		if(strncmp(p, "name ", 5) == 0){	/* set file name */
			pp = p+5;
			m = 5;
			q = memchr(pp, '\n', e-pp);
			if(q==nil || q==pp){
				err = Ebadctl;
				break;
			}
			*q = 0;
			nulls = FALSE;
			cvttorunes(pp, q-pp, r, &nb, &nr, &nulls);
			if(nulls){
				err = "nulls in file name";
				break;
			}
			for(i=0; i<nr; i++)
				if(r[i] <= ' '){
					err = "bad character in file name";
					goto out;
				}
out:
			seq++;
			filemark(w->body.file);
			winsetname(w, r, nr);
			m += (q+1) - pp;
		}else
		if(strncmp(p, "dump ", 5) == 0){	/* set dump string */
			pp = p+5;
			m = 5;
			q = memchr(pp, '\n', e-pp);
			if(q==nil || q==pp){
				err = Ebadctl;
				break;
			}
			*q = 0;
			nulls = FALSE;
			cvttorunes(pp, q-pp, r, &nb, &nr, &nulls);
			if(nulls){
				err = "nulls in dump string";
				break;
			}
			w->dumpstr = runetobyte(r, nr);
			m += (q+1) - pp;
		}else
		if(strncmp(p, "dumpdir ", 8) == 0){	/* set dump directory */
			pp = p+8;
			m = 8;
			q = memchr(pp, '\n', e-pp);
			if(q==nil || q==pp){
				err = Ebadctl;
				break;
			}
			*q = 0;
			nulls = FALSE;
			cvttorunes(pp, q-pp, r, &nb, &nr, &nulls);
			if(nulls){
				err = "nulls in dump directory string";
				break;
			}
			w->dumpdir = runetobyte(r, nr);
			m += (q+1) - pp;
		}else
		if(strncmp(p, "delete", 6) == 0){	/* delete for sure */
			colclose(w->col, w, TRUE);
			m = 6;
		}else
		if(strncmp(p, "del", 3) == 0){	/* delete, but check dirty */
			if(!winclean(w, TRUE)){
				err = "file dirty";
				break;
			}
			colclose(w->col, w, TRUE);
			m = 3;
		}else
		if(strncmp(p, "get", 3) == 0){	/* get file */
			get(&w->body, nil, nil, FALSE, XXX, nil, 0);
			m = 3;
		}else
		if(strncmp(p, "put", 3) == 0){	/* put file */
			put(&w->body, nil, nil, XXX, XXX, nil, 0);
			m = 3;
		}else
		if(strncmp(p, "dot=addr", 8) == 0){	/* set dot */
			textcommit(&w->body, TRUE);
			clampaddr(w);
			w->body.q0 = w->addr.q0;
			w->body.q1 = w->addr.q1;
			textsetselect(&w->body, w->body.q0, w->body.q1);
			settag = TRUE;
			m = 8;
		}else
		if(strncmp(p, "addr=dot", 8) == 0){	/* set addr */
			w->addr.q0 = w->body.q0;
			w->addr.q1 = w->body.q1;
			m = 8;
		}else
		if(strncmp(p, "limit=addr", 10) == 0){	/* set limit */
			textcommit(&w->body, TRUE);
			clampaddr(w);
			w->limit.q0 = w->addr.q0;
			w->limit.q1 = w->addr.q1;
			m = 10;
		}else
		if(strncmp(p, "nomark", 6) == 0){	/* turn off automatic marking */
			w->nomark = TRUE;
			m = 6;
		}else
		if(strncmp(p, "mark", 4) == 0){	/* mark file */
			seq++;
			filemark(w->body.file);
			settag = TRUE;
			m = 4;
		}else
		if(strncmp(p, "nomenu", 6) == 0){	/* turn off automatic menu */
			w->filemenu = FALSE;
			m = 6;
		}else
		if(strncmp(p, "menu", 4) == 0){	/* enable automatic menu */
			w->filemenu = TRUE;
			m = 4;
		}else
		if(strncmp(p, "noscroll", 8) == 0){	/* turn off automatic scrolling */
			w->noscroll = TRUE;
			m = 8;
		}else
		if(strncmp(p, "cleartag", 8) == 0){	/* wipe tag right of bar */
			wincleartag(w);
			settag = TRUE;
			m = 8;
		}else
		if(strncmp(p, "scroll", 6) == 0){	/* turn on automatic scrolling (writes to body only) */
			w->noscroll = FALSE;
			m = 6;
		}else{
			err = Ebadctl;
			break;
		}
		while(p[m] == '\n')
			m++;
	}

	if(isfbuf)
		fbuffree(r);
	else
		free(r);
	if(err)
		n = 0;
	fc.count = n;
	respond(x, &fc, err);
	if(settag)
		winsettag(w);
	if(scrdraw)
		textscrdraw(&w->body);
}

void
xfideventwrite(Xfid *x, Window *w)
{
	Fcall fc;
	int m, n;
	Rune *r;
	char *err, *p, *q;
	int isfbuf;
	Text *t;
	int c;
	uint q0, q1;

	err = nil;
	isfbuf = TRUE;
	if(x->count < RBUFSIZE)
		r = fbufalloc();
	else{
		isfbuf = FALSE;
		r = emalloc(x->count*UTFmax+1);
	}
	for(n=0; n<x->count; n+=m){
		p = x->data+n;
		w->owner = *p++;	/* disgusting */
		c = *p++;
		while(*p == ' ')
			p++;
		q0 = strtoul(p, &q, 10);
		if(q == p)
			goto Rescue;
		p = q;
		while(*p == ' ')
			p++;
		q1 = strtoul(p, &q, 10);
		if(q == p)
			goto Rescue;
		p = q;
		while(*p == ' ')
			p++;
		if(*p++ != '\n')
			goto Rescue;
		m = p-(x->data+n);
		if('a'<=c && c<='z')
			t = &w->tag;
		else if('A'<=c && c<='Z')
			t = &w->body;
		else
			goto Rescue;
		if(q0>t->file->nc || q1>t->file->nc || q0>q1)
			goto Rescue;

		qlock(&row);	/* just like mousethread */
		switch(c){
		case 'x':
		case 'X':
			execute(t, q0, q1, TRUE, nil);
			break;
		case 'l':
		case 'L':
			look3(t, q0, q1, TRUE);
			break;
		default:
			qunlock(&row);
			goto Rescue;
		}
		qunlock(&row);

	}

    Out:
	if(isfbuf)
		fbuffree(r);
	else
		free(r);
	if(err)
		n = 0;
	fc.count = n;
	respond(x, &fc, err);
	return;

    Rescue:
	err = Ebadevent;
	goto Out;
}

void
xfidutfread(Xfid *x, Text *t, uint q1, int qid)
{
	Fcall fc;
	Window *w;
	Rune *r;
	char *b, *b1;
	uint q, off, boff;
	int m, n, nr, nb;

	w = t->w;
	wincommit(w, t);
	off = x->offset;
	r = fbufalloc();
	b = fbufalloc();
	b1 = fbufalloc();
	n = 0;
	if(qid==w->utflastqid && off>=w->utflastboff && w->utflastq<=q1){
		boff = w->utflastboff;
		q = w->utflastq;
	}else{
		/* BUG: stupid code: scan from beginning */
		boff = 0;
		q = 0;
	}
	w->utflastqid = qid;
	while(q<q1 && n<x->count){
		/*
		 * Updating here avoids partial rune problem: we're always on a
		 * char boundary. The cost is we will usually do one more read
		 * than we really need, but that's better than being n^2.
		 */
		w->utflastboff = boff;
		w->utflastq = q;
		nr = q1-q;
		if(nr > BUFSIZE/UTFmax)
			nr = BUFSIZE/UTFmax;
		bufread(t->file, q, r, nr);
		nb = snprint(b, BUFSIZE+1, "%.*S", nr, r);
		if(boff >= off){
			m = nb;
			if(boff+m > off+x->count)
				m = off+x->count - boff;
			memmove(b1+n, b, m);
			n += m;
		}else if(boff+nb > off){
			if(n != 0)
				error("bad count in utfrune");
			m = nb - (off-boff);
			if(m > x->count)
				m = x->count;
			memmove(b1, b+(off-boff), m);
			n += m;
		}
		boff += nb;
		q += nr;
	}
	fbuffree(r);
	fbuffree(b);
	fc.count = n;
	fc.data = b1;
	respond(x, &fc, nil);
	fbuffree(b1);
}

int
xfidruneread(Xfid *x, Text *t, uint q0, uint q1)
{
	Fcall fc;
	Window *w;
	Rune *r, junk;
	char *b, *b1;
	uint q, boff;
	int i, rw, m, n, nr, nb;

	w = t->w;
	wincommit(w, t);
	r = fbufalloc();
	b = fbufalloc();
	b1 = fbufalloc();
	n = 0;
	q = q0;
	boff = 0;
	while(q<q1 && n<x->count){
		nr = q1-q;
		if(nr > BUFSIZE/UTFmax)
			nr = BUFSIZE/UTFmax;
		bufread(t->file, q, r, nr);
		nb = snprint(b, BUFSIZE+1, "%.*S", nr, r);
		m = nb;
		if(boff+m > x->count){
			i = x->count - boff;
			/* copy whole runes only */
			m = 0;
			nr = 0;
			while(m < i){
				rw = chartorune(&junk, b+m);
				if(m+rw > i)
					break;
				m += rw;
				nr++;
			}
			if(m == 0)
				break;
		}
		memmove(b1+n, b, m);
		n += m;
		boff += nb;
		q += nr;
	}
	fbuffree(r);
	fbuffree(b);
	fc.count = n;
	fc.data = b1;
	respond(x, &fc, nil);
	fbuffree(b1);
	return q-q0;
}

void
xfideventread(Xfid *x, Window *w)
{
	Fcall fc;
	char *b;
	int i, n;

	i = 0;
	x->flushed = FALSE;
	while(w->nevents == 0){
		if(i){
			if(!x->flushed)
				respond(x, &fc, "window shut down");
			return;
		}
		w->eventx = x;
		winunlock(w);
		recvp(x->c);
		winlock(w, 'F');
		i++;
	}

	n = w->nevents;
	if(n > x->count)
		n = x->count;
	fc.count = n;
	fc.data = w->events;
	respond(x, &fc, nil);
	b = w->events;
	w->events = estrdup(w->events+n);
	free(b);
	w->nevents -= n;
}

void
xfidindexread(Xfid *x)
{
	Fcall fc;
	int i, j, m, n, nmax, isbuf, cnt, off;
	Window *w;
	char *b;
	Rune *r;
	Column *c;

	qlock(&row);
	nmax = 0;
	for(j=0; j<row.ncol; j++){
		c = row.col[j];
		for(i=0; i<c->nw; i++){
			w = c->w[i];
			nmax += Ctlsize + w->tag.file->nc*UTFmax + 1;
		}
	}
	nmax++;
	isbuf = (nmax<=RBUFSIZE);
	if(isbuf)
		b = (char*)x->buf;
	else
		b = emalloc(nmax);
	r = fbufalloc();
	n = 0;
	for(j=0; j<row.ncol; j++){
		c = row.col[j];
		for(i=0; i<c->nw; i++){
			w = c->w[i];
			/* only show the currently active window of a set */
			if(w->body.file->curtext != &w->body)
				continue;
			winctlprint(w, b+n, 0);
			n += Ctlsize;
			m = min(RBUFSIZE, w->tag.file->nc);
			bufread(w->tag.file, 0, r, m);
			m = n + snprint(b+n, nmax-n-1, "%.*S", m, r);
			while(n<m && b[n]!='\n')
				n++;
			b[n++] = '\n';
		}
	}
	qunlock(&row);
	off = x->offset;
	cnt = x->count;
	if(off > n)
		off = n;
	if(off+cnt > n)
		cnt = n-off;
	fc.count = cnt;
	memmove(r, b+off, cnt);
	fc.data = (char*)r;
	if(!isbuf)
		free(b);
	respond(x, &fc, nil);
	fbuffree(r);
}