ref: 1335a57865c1a966a58437779d15aa63a775d64e
dir: /sys/src/cmd/acme/xfid.c/
#include <u.h>
#include <libc.h>
#include <draw.h>
#include <thread.h>
#include <cursor.h>
#include <mouse.h>
#include <keyboard.h>
#include <frame.h>
#include <fcall.h>
#include <plumb.h>
#include "dat.h"
#include "fns.h"
enum
{
Ctlsize = 5*12
};
char Edel[] = "deleted window";
char Ebadctl[] = "ill-formed control message";
char Ebadaddr[] = "bad address syntax";
char Eaddr[] = "address out of range";
char Einuse[] = "already in use";
char Ebadevent[] = "bad event syntax";
extern char Eperm[];
static
void
clampaddr(Window *w)
{
if(w->addr.q0 < 0)
w->addr.q0 = 0;
if(w->addr.q1 < 0)
w->addr.q1 = 0;
if(w->addr.q0 > w->body.file->nc)
w->addr.q0 = w->body.file->nc;
if(w->addr.q1 > w->body.file->nc)
w->addr.q1 = w->body.file->nc;
}
void
xfidctl(void *arg)
{
Xfid *x;
void (*f)(Xfid*);
threadsetname("xfidctlthread");
x = arg;
for(;;){
f = recvp(x->c);
(*f)(x);
flushimage(display, 1);
sendp(cxfidfree, x);
}
}
void
xfidflush(Xfid *x)
{
Fcall fc;
int i, j;
Window *w;
Column *c;
Xfid *wx;
/* search windows for matching tag */
qlock(&row);
for(j=0; j<row.ncol; j++){
c = row.col[j];
for(i=0; i<c->nw; i++){
w = c->w[i];
winlock(w, 'E');
wx = w->eventx;
if(wx!=nil && wx->tag==x->oldtag){
w->eventx = nil;
wx->flushed = TRUE;
sendp(wx->c, nil);
winunlock(w);
goto out;
}
winunlock(w);
}
}
out:
qunlock(&row);
respond(x, &fc, nil);
}
void
xfidopen(Xfid *x)
{
Fcall fc;
Window *w;
Text *t;
char *s;
Rune *r;
int m, n, q, q0, q1;
w = x->f->w;
t = &w->body;
if(w){
winlock(w, 'E');
q = FILE(x->f->qid);
switch(q){
case QWaddr:
if(w->nopen[q]++ == 0){
w->addr = (Range){0,0};
w->limit = (Range){-1,-1};
}
break;
case QWdata:
case QWxdata:
w->nopen[q]++;
break;
case QWevent:
if(w->nopen[q]++ == 0){
if(!w->isdir && w->col!=nil){
w->filemenu = FALSE;
winsettag(w);
}
}
break;
case QWrdsel:
/*
* Use a temporary file.
* A pipe would be the obvious, but we can't afford the
* broken pipe notification. Using the code to read QWbody
* is n², which should probably also be fixed. Even then,
* though, we'd need to squirrel away the data in case it's
* modified during the operation, e.g. by |sort
*/
if(w->rdselfd >= 0){
winunlock(w);
respond(x, &fc, Einuse);
return;
}
w->rdselfd = tempfile();
if(w->rdselfd < 0){
winunlock(w);
respond(x, &fc, "can't create temp file");
return;
}
w->nopen[q]++;
q0 = t->q0;
q1 = t->q1;
r = fbufalloc();
s = fbufalloc();
while(q0 < q1){
n = q1 - q0;
if(n > (BUFSIZE-1)/UTFmax)
n = (BUFSIZE-1)/UTFmax;
bufread(t->file, q0, r, n);
m = snprint(s, BUFSIZE, "%.*S", n, r);
if(write(w->rdselfd, s, m) != m){
warning(nil, "can't write temp file for pipe command %r\n");
break;
}
q0 += n;
}
fbuffree(s);
fbuffree(r);
break;
case QWwrsel:
w->nopen[q]++;
seq++;
filemark(t->file);
cut(t, t, nil, FALSE, TRUE, nil, 0);
w->wrselrange = (Range){t->q1, t->q1};
w->nomark = TRUE;
break;
case QWeditout:
if(editing == FALSE){
winunlock(w);
respond(x, &fc, Eperm);
return;
}
w->wrselrange = (Range){t->q1, t->q1};
break;
}
winunlock(w);
}
fc.qid = x->f->qid;
fc.iounit = messagesize-IOHDRSZ;
x->f->open = TRUE;
respond(x, &fc, nil);
}
void
xfidclose(Xfid *x)
{
Fcall fc;
Window *w;
int q;
Text *t;
w = x->f->w;
x->f->busy = FALSE;
if(x->f->open == FALSE){
if(w != nil)
winclose(w);
respond(x, &fc, nil);
return;
}
x->f->open = FALSE;
if(w){
winlock(w, 'E');
q = FILE(x->f->qid);
switch(q){
case QWctl:
if(w->ctlfid!=~0 && w->ctlfid==x->f->fid){
w->ctlfid = ~0;
qunlock(&w->ctllock);
}
break;
case QWdata:
case QWxdata:
w->nomark = FALSE;
/* fall through */
case QWaddr:
case QWevent: /* BUG: do we need to shut down Xfid? */
if(--w->nopen[q] == 0){
if(q == QWdata || q == QWxdata)
w->nomark = FALSE;
if(q==QWevent && !w->isdir && w->col!=nil){
w->filemenu = TRUE;
winsettag(w);
}
if(q == QWevent){
free(w->dumpstr);
free(w->dumpdir);
w->dumpstr = nil;
w->dumpdir = nil;
}
}
break;
case QWrdsel:
close(w->rdselfd);
w->rdselfd = -1;
break;
case QWwrsel:
w->nomark = FALSE;
t = &w->body;
/* before: only did this if !w->noscroll, but that didn't seem right in practice */
textshow(t, min(w->wrselrange.q0, t->file->nc),
min(w->wrselrange.q1, t->file->nc), 1);
textscrdraw(t);
break;
}
winunlock(w);
winclose(w);
}
respond(x, &fc, nil);
}
void
xfidread(Xfid *x)
{
Fcall fc;
int n, q;
uint off;
char *b;
char buf[256];
Window *w;
q = FILE(x->f->qid);
w = x->f->w;
if(w == nil){
fc.count = 0;
switch(q){
case Qcons:
case Qlabel:
break;
case Qindex:
xfidindexread(x);
return;
default:
warning(nil, "unknown qid %d\n", q);
break;
}
respond(x, &fc, nil);
return;
}
winlock(w, 'F');
if(w->col == nil){
winunlock(w);
respond(x, &fc, Edel);
return;
}
off = x->offset;
switch(q){
case QWaddr:
textcommit(&w->body, TRUE);
clampaddr(w);
sprint(buf, "%11d %11d ", w->addr.q0, w->addr.q1);
goto Readbuf;
case QWbody:
xfidutfread(x, &w->body, w->body.file->nc, QWbody);
break;
case QWctl:
b = winctlprint(w, buf, 1);
goto Readb;
Readbuf:
b = buf;
Readb:
n = strlen(b);
if(off > n)
off = n;
if(off+x->count > n)
x->count = n-off;
fc.count = x->count;
fc.data = b+off;
respond(x, &fc, nil);
if(b != buf)
free(b);
break;
case QWevent:
xfideventread(x, w);
break;
case QWdata:
/* BUG: what should happen if q1 > q0? */
if(w->addr.q0 > w->body.file->nc){
respond(x, &fc, Eaddr);
break;
}
w->addr.q0 += xfidruneread(x, &w->body, w->addr.q0, w->body.file->nc);
w->addr.q1 = w->addr.q0;
break;
case QWxdata:
/* BUG: what should happen if q1 > q0? */
if(w->addr.q0 > w->body.file->nc){
respond(x, &fc, Eaddr);
break;
}
w->addr.q0 += xfidruneread(x, &w->body, w->addr.q0, w->addr.q1);
break;
case QWtag:
xfidutfread(x, &w->tag, w->tag.file->nc, QWtag);
break;
case QWrdsel:
seek(w->rdselfd, off, 0);
n = x->count;
if(n > BUFSIZE)
n = BUFSIZE;
b = fbufalloc();
n = read(w->rdselfd, b, n);
if(n < 0){
respond(x, &fc, "I/O error in temp file");
break;
}
fc.count = n;
fc.data = b;
respond(x, &fc, nil);
fbuffree(b);
break;
default:
sprint(buf, "unknown qid %d in read", q);
respond(x, &fc, nil);
}
winunlock(w);
}
static Rune*
fullrunewrite(Xfid *x, int *inr)
{
int q, cnt, c, nb, nr;
Rune *r;
q = x->f->nrpart;
cnt = x->count;
if(q > 0){
memmove(x->data+q, x->data, cnt); /* there's room; see fsysproc */
memmove(x->data, x->f->rpart, q);
cnt += q;
x->f->nrpart = 0;
}
r = runemalloc(cnt);
cvttorunes(x->data, cnt-UTFmax, r, &nb, &nr, nil);
/* approach end of buffer */
while(fullrune(x->data+nb, cnt-nb)){
c = nb;
nb += chartorune(&r[nr], x->data+c);
if(r[nr])
nr++;
}
if(nb < cnt){
memmove(x->f->rpart, x->data+nb, cnt-nb);
x->f->nrpart = cnt-nb;
}
*inr = nr;
return r;
}
void
xfidwrite(Xfid *x)
{
Fcall fc;
int c, qid, nb, nr, eval;
char buf[64], *err;
Window *w;
Rune *r;
Range a;
Text *t;
uint q0, tq0, tq1;
qid = FILE(x->f->qid);
w = x->f->w;
if(w){
c = 'F';
if(qid==QWtag || qid==QWbody)
c = 'E';
winlock(w, c);
if(w->col == nil){
winunlock(w);
respond(x, &fc, Edel);
return;
}
}
x->data[x->count] = 0;
switch(qid){
case Qcons:
w = errorwin(x->f->mntdir, 'X');
t=&w->body;
goto BodyTag;
case Qlabel:
fc.count = x->count;
respond(x, &fc, nil);
break;
case QWaddr:
x->data[x->count] = 0;
r = bytetorune(x->data, &nr);
t = &w->body;
wincommit(w, t);
eval = TRUE;
a = address(x->f->mntdir, t, w->limit, w->addr, r, 0, nr, rgetc, &eval, (uint*)&nb);
free(r);
if(nb < nr){
respond(x, &fc, Ebadaddr);
break;
}
if(!eval){
respond(x, &fc, Eaddr);
break;
}
w->addr = a;
fc.count = x->count;
respond(x, &fc, nil);
break;
case Qeditout:
case QWeditout:
r = fullrunewrite(x, &nr);
if(w)
err = edittext(w, w->wrselrange.q1, r, nr);
else
err = edittext(nil, 0, r, nr);
free(r);
if(err != nil){
respond(x, &fc, err);
break;
}
fc.count = x->count;
respond(x, &fc, nil);
break;
case QWerrors:
w = errorwinforwin(w);
t = &w->body;
goto BodyTag;
case QWbody:
case QWwrsel:
t = &w->body;
goto BodyTag;
case QWctl:
xfidctlwrite(x, w);
break;
case QWdata:
a = w->addr;
t = &w->body;
wincommit(w, t);
if(a.q0>t->file->nc || a.q1>t->file->nc){
respond(x, &fc, Eaddr);
break;
}
r = runemalloc(x->count);
cvttorunes(x->data, x->count, r, &nb, &nr, nil);
if(w->nomark == FALSE){
seq++;
filemark(t->file);
}
q0 = a.q0;
if(a.q1 > q0){
textdelete(t, q0, a.q1, TRUE);
w->addr.q1 = q0;
}
tq0 = t->q0;
tq1 = t->q1;
textinsert(t, q0, r, nr, TRUE);
if(tq0 >= q0)
tq0 += nr;
if(tq1 >= q0)
tq1 += nr;
textsetselect(t, tq0, tq1);
if(!t->w->noscroll)
textshow(t, q0, q0+nr, 0);
textscrdraw(t);
winsettag(w);
free(r);
w->addr.q0 += nr;
w->addr.q1 = w->addr.q0;
fc.count = x->count;
respond(x, &fc, nil);
break;
case QWevent:
xfideventwrite(x, w);
break;
case QWtag:
t = &w->tag;
goto BodyTag;
BodyTag:
r = fullrunewrite(x, &nr);
if(nr > 0){
wincommit(w, t);
if(qid == QWwrsel){
q0 = w->wrselrange.q1;
if(q0 > t->file->nc)
q0 = t->file->nc;
}else
q0 = t->file->nc;
if(qid == QWtag)
textinsert(t, q0, r, nr, TRUE);
else{
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 scrdraw, settag;
Text *t;
err = nil;
e = x->data+x->count;
scrdraw = FALSE;
settag = 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++;
}
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;
Text *t;
int c;
uint q0, q1;
err = nil;
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:
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 = emalloc(x->count);
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-1)/UTFmax)
nr = (BUFSIZE-1)/UTFmax;
bufread(t->file, q, r, nr);
nb = snprint(b, BUFSIZE, "%.*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);
free(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 = emalloc(x->count);
n = 0;
q = q0;
boff = 0;
while(q<q1 && n<x->count){
nr = q1-q;
if(nr > (BUFSIZE-1)/UTFmax)
nr = (BUFSIZE-1)/UTFmax;
bufread(t->file, q, r, nr);
nb = snprint(b, BUFSIZE, "%.*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);
free(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);
}