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implement Trfs;
include "sys.m";
sys: Sys;
include "draw.m";
include "styx.m";
styx: Styx;
Rmsg, Tmsg: import styx;
Trfs: module
{
init: fn(nil: ref Draw->Context, nil: list of string);
};
Fid: adt {
fid: int;
isdir: int;
aux: int;
};
Table: adt[T] {
items: array of list of (int, T);
nilval: T;
new: fn(nslots: int, nilval: T): ref Table[T];
add: fn(t: self ref Table, id: int, x: T): int;
del: fn(t: self ref Table, id: int): T;
find: fn(t: self ref Table, id: int): T;
};
NBspace: con 16r00A0; # Unicode `no-break' space (looks like a faint box in some fonts)
NBspacelen: con 2; # length of it in utf-8
msize: int;
lock: chan of int;
fids: ref Table[ref Fid];
tfids: ref Table[ref Fid];
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
styx = load Styx Styx->PATH;
if(len args != 3){
sys->fprint(sys->fildes(2), "usage: trfs dir mountpoint\n");
raise "fail:usage";
}
dir := hd tl args;
mntpt := hd tl tl args;
p := array[2] of ref Sys->FD;
q := array[2] of ref Sys->FD;
fids = Table[ref Fid].new(11, nil);
tfids = Table[ref Fid].new(11, nil);
lock = chan[1] of int;
styx->init();
sys->pipe(p);
sys->pipe(q);
if(sys->export(q[0], dir, Sys->EXPASYNC) < 0)
fatal("can't export " + dir);
spawn trfsin(p[1], q[1]);
spawn trfsout(p[1], q[1]);
if(sys->mount(p[0], nil, mntpt, Sys->MREPL|Sys->MCREATE, nil) < 0)
fatal("can't mount on " + mntpt);
}
trfsin(cfd, sfd: ref Sys->FD)
{
while((t:=Tmsg.read(cfd, msize)) != nil){
pick m := t {
Clunk or
Remove =>
fids.del(m.fid);
Create =>
fid := ref Fid(m.fid, 0, 0);
fids.add(m.fid, fid);
addtfid(m.tag, fid);
m.name = tr(m.name, NBspace, ' ');
Open =>
fid := ref Fid(m.fid, 0, 0);
fids.add(m.fid, fid);
addtfid(m.tag, fid);
Read =>
fid := fids.find(m.fid);
addtfid(m.tag, fid);
if(fid.isdir){
m.count /= NBspacelen; # translated strings might grow by this much
if(m.offset == big 0)
fid.aux = 0;
m.offset -= big fid.aux;
}
Walk =>
for(i:=0; i<len m.names; i++)
m.names[i] = tr(m.names[i], NBspace, ' ');
Wstat =>
m.stat.name = tr(m.stat.name, NBspace, ' ');
}
sys->write(sfd, t.pack(), t.packedsize());
}
}
trfsout(cfd, sfd: ref Sys->FD)
{
b := array[Styx->MAXFDATA] of byte;
while((r := Rmsg.read(sfd, msize)) != nil){
pick m := r {
Version =>
msize = m.msize;
if(msize > len b)
b = array[msize] of byte; # a bit more than needed but doesn't matter
Create or
Open =>
fid := deltfid(m.tag);
fid.isdir = m.qid.qtype & Sys->QTDIR;
Read =>
fid := deltfid(m.tag);
if(fid.isdir){
bs := 0;
for(n := 0; n < len m.data; ){
(ds, d) := styx->unpackdir(m.data[n:]);
if(ds <= 0)
break;
d.name = tr(d.name, ' ', NBspace);
b[bs:] = styx->packdir(d);
bs += styx->packdirsize(d);
n += ds;
}
fid.aux += bs-n;
m.data = b[0:bs];
}
Stat =>
m.stat.name = tr(m.stat.name, ' ', NBspace);
}
sys->write(cfd, r.pack(), r.packedsize());
}
}
tr(name: string, c1, c2: int): string
{
for(i:=0; i<len name; i++)
if(name[i] == c1)
name[i] = c2;
return name;
}
Table[T].new(nslots: int, nilval: T): ref Table[T]
{
if(nslots == 0)
nslots = 13;
return ref Table[T](array[nslots] of list of (int, T), nilval);
}
Table[T].add(t: self ref Table[T], id: int, x: T): int
{
slot := id % len t.items;
for(q := t.items[slot]; q != nil; q = tl q)
if((hd q).t0 == id)
return 0;
t.items[slot] = (id, x) :: t.items[slot];
return 1;
}
Table[T].del(t: self ref Table[T], id: int): T
{
p: list of (int, T);
slot := id % len t.items;
for(q := t.items[slot]; q != nil; q = tl q){
if((hd q).t0 == id){
t.items[slot] = join(p, tl q);
return (hd q).t1;
}
p = hd q :: p;
}
return t.nilval;
}
Table[T].find(t: self ref Table[T], id: int): T
{
for(p := t.items[id % len t.items]; p != nil; p = tl p)
if((hd p).t0 == id)
return (hd p).t1;
return t.nilval;
}
join[T](x, y: list of (int, T)): list of (int, T)
{
for(; x != nil; x = tl x)
y = hd x :: y;
return y;
}
addtfid(t: int, fid: ref Fid)
{
lock <-= 1;
tfids.add(t, fid);
<- lock;
}
deltfid(t: int): ref Fid
{
lock <-= 1;
r := tfids.del(t);
<- lock;
return r;
}
fatal(s: string)
{
sys->fprint(sys->fildes(2), "trfs: %s: %r\n", s);
raise "fail:error";
}
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