static void
gencurrent(Wcache *w, Qid *q, char *file, char *lock, uint32_t *t,
Whist **wp, int n)
{
Dir *d;
Whist *wh;
if(*wp && *t+Tcache >= time(0))
return;
wlock(w);
if(*wp && *t+Tcache >= time(0)){
wunlock(w);
return;
}
if(((d = wdirstat(file)) == nil) || (d->qid.path==q->path && d->qid.vers==q->vers)){
*t = time(0);
wunlock(w);
free(d);
return;
}
free(d);
if(wh = readwhist(file, lock, q)){
wh->n = n;
*t = time(0);
closewhist(*wp);
*wp = wh;
}
else fprint(2, "error file=%s lock=%s %r\n", file, lock);
wunlock(w);
}
void
voidcache(int n)
{
Wcache *c;
rlock(&cachelock);
if(c = findcache(n)){
wlock(c);
c->tcurrent = 0;
c->thist = 0;
/* aggressively free memory */
closewhist(c->hist);
c->hist = nil;
closewhist(c->current);
c->current = nil;
wunlock(c);
}
runlock(&cachelock);
}
static void
fsopen(Req *r)
{
int t;
uvlong path;
Aux *a;
Fid *fid;
Whist *wh;
fid = r->fid;
path = fid->qid.path;
t = qidtype(fid->qid.path);
if((r->ifcall.mode != OREAD && t != Fnew && t != Fmap)
|| (r->ifcall.mode&ORCLOSE)){
respond(r, "permission denied");
return;
}
a = fid->aux;
switch(t){
case Droot:
currentmap(0);
rlock(&maplock);
a->map = map;
incref(map);
runlock(&maplock);
respond(r, nil);
break;
case D1st:
if((wh = gethistory(qidnum(path))) == nil){
respond(r, "file does not exist");
return;
}
closewhist(a->w);
a->w = wh;
a->n = a->w->ndoc-1;
r->ofcall.qid.vers = wh->doc[a->n].time;
r->fid->qid = r->ofcall.qid;
respond(r, nil);
break;
case D2nd:
respond(r, nil);
break;
case Fnew:
a->s = s_copy("");
respond(r, nil);
break;
case Fmap:
case F1st:
case F2nd:
respond(r, nil);
break;
default:
respond(r, "programmer error");
break;
}
}
static char*
fswalk1(Fid *fid, char *name, Qid *qid)
{
char *q;
int i, isdotdot, n, t;
uvlong path;
Aux *a;
Whist *wh;
String *s;
isdotdot = strcmp(name, "..")==0;
n = strtoul(name, &q, 10);
path = fid->qid.path;
a = fid->aux;
switch(qidtype(path)){
case 0:
return "wikifs: bad path in server (bug)";
case Droot:
if(isdotdot){
*qid = fid->qid;
return nil;
}
if(strcmp(name, "new")==0){
*qid = (Qid){mkqid(Fnew, 0, 0, 0), 0, 0};
return nil;
}
if(strcmp(name, "map")==0){
*qid = (Qid){mkqid(Fmap, 0, 0, 0), 0, 0};
return nil;
}
if((*q!='\0' || (wh=getcurrent(n))==nil)
&& (wh=getcurrentbyname(name))==nil)
return "file does not exist";
*qid = (Qid){mkqid(D1st, wh->n, 0, 0), wh->doc->time, QTDIR};
a->w = wh;
return nil;
case D1st:
if(isdotdot){
*qid = (Qid){mkqid(Droot, 0, 0, 0), 0, QTDIR};
return nil;
}
/* handle history directories */
if(*q == '\0'){
if((wh = gethistory(qidnum(path))) == nil)
return "file does not exist";
for(i=0; i<wh->ndoc; i++)
if(wh->doc[i].time == n)
break;
if(i==wh->ndoc){
closewhist(wh);
return "file does not exist";
}
closewhist(a->w);
a->w = wh;
a->n = i;
*qid = (Qid){mkqid(D2nd, qidnum(path), i, 0), wh->doc[i].time, QTDIR};
return nil;
}
/* handle files other than index */
for(i=0; i<nelem(filelist); i++){
if(strcmp(name, filelist[i])==0){
if(needhist[i]){
if((wh = gethistory(qidnum(path))) == nil)
return "file does not exist";
closewhist(a->w);
a->w = wh;
}
*qid = (Qid){mkqid(F1st, qidnum(path), 0, i), a->w->doc->time, 0};
goto Gotfile;
}
}
return "file does not exist";
case D2nd:
if(isdotdot){
/*
* Can't use a->w[a->ndoc-1] because that
* might be a failed write rather than the real one.
*/
*qid = (Qid){mkqid(D1st, qidnum(path), 0, 0), 0, QTDIR};
if((wh = getcurrent(qidnum(path))) == nil)
return "file does not exist";
closewhist(a->w);
a->w = wh;
a->n = 0;
return nil;
}
for(i=0; i<=Qraw; i++){
if(strcmp(name, filelist[i])==0){
*qid = (Qid){mkqid(F2nd, qidnum(path), qidvers(path), i), a->w->doc->time, 0};
goto Gotfile;
}
}
return "file does not exist";
default:
return "bad programming";
}
/* not reached */
Gotfile:
t = qidtype(qid->path);
switch(qidfile(qid->path)){
case Qindexhtml:
s = tohtml(a->w, a->w->doc+a->n,
t==F1st? Tpage : Toldpage);
break;
case Qindextxt:
s = totext(a->w, a->w->doc+a->n,
t==F1st? Tpage : Toldpage);
break;
case Qraw:
s = s_copy(a->w->title);
s = s_append(s, "\n");
s = doctext(s, &a->w->doc[a->n]);
break;
case Qhistoryhtml:
s = tohtml(a->w, a->w->doc+a->n, Thistory);
break;
case Qhistorytxt:
s = totext(a->w, a->w->doc+a->n, Thistory);
break;
case Qdiffhtml:
s = tohtml(a->w, a->w->doc+a->n, Tdiff);
break;
case Qedithtml:
s = tohtml(a->w, a->w->doc+a->n, Tedit);
break;
case Qwerrorhtml:
s = tohtml(a->w, a->w->doc+a->n, Twerror);
break;
case Qwerrortxt:
s = totext(a->w, a->w->doc+a->n, Twerror);
break;
case Qhttplogin:
s = httplogin();
break;
default:
return "internal error";
}
a->s = s;
return nil;
}
static Whist*
getcache(int n, int hist)
{
int i, isw;
uint32_t t;
Wcache *c, **cp, **evict;
Whist *wh;
isw = 0;
rlock(&cachelock);
if(c = findcache(n)){
Found:
current(c);
if(hist)
currenthist(c);
rlock(c);
if(hist)
wh = c->hist;
else
wh = c->current;
if(wh)
incref(wh);
runlock(c);
if(isw)
wunlock(&cachelock);
else
runlock(&cachelock);
return wh;
}
runlock(&cachelock);
wlock(&cachelock);
if(c = findcache(n)){
isw = 1; /* better to downgrade lock but can't */
goto Found;
}
if(ncache < Mcache){
Alloc:
c = emalloc(sizeof *c);
ncache++;
}else{
/* find something to evict. */
t = ~0;
evict = nil;
for(i=0; i<Nhash; i++){
for(cp=&tab[i], c=*cp; c; cp=&c->hash, c=*cp){
if(c->use < t
&& (!c->hist || c->hist->ref==1)
&& (!c->current || c->current->ref==1)){
evict = cp;
t = c->use;
}
}
}
if(evict == nil){
fprint(2, "wikifs: nothing to evict\n");
goto Alloc;
}
c = *evict;
*evict = c->hash;
closewhist(c->current);
closewhist(c->hist);
memset(c, 0, sizeof *c);
}
c->n = n;
c->hash = tab[n%Nhash];
tab[n%Nhash] = c;
isw = 1;
goto Found;
}
