ref: c116550e6a41572796e4db65e4f6acbcb3d9d6f8
dir: /appl/collab/servers/chatsrv.b/
implement Service; # # simple text-based chat service # include "sys.m"; sys: Sys; Qid: import Sys; include "styx.m"; styx: Styx; Tmsg, Rmsg: import Styx; include "styxservers.m"; styxservers: Styxservers; Styxserver, Navigator: import styxservers; nametree: Nametree; Tree: import nametree; include "../service.m"; Qdir, Qusers, Qmsgs: con iota; tc: chan of ref Tmsg; srv: ref Styxserver; user := "inferno"; dir(name: string, perm: int, path: int): Sys->Dir { d := sys->zerodir; d.name = name; d.uid = user; d.gid = user; d.qid.path = big path; if(perm & Sys->DMDIR) d.qid.qtype = Sys->QTDIR; else d.qid.qtype = Sys->QTFILE; d.mode = perm; return d; } init(nil: list of string): (string, string, ref Sys->FD) { sys = load Sys Sys->PATH; styx = load Styx Styx->PATH; if(styx == nil) return (sys->sprint("can't load %s: %r", Styx->PATH), nil, nil); styxservers = load Styxservers Styxservers->PATH; if(styxservers == nil) return (sys->sprint("can't load %s: %r", Styxservers->PATH), nil, nil); nametree = load Nametree Nametree->PATH; if(nametree == nil) return (sys->sprint("can't load %s: %r", Nametree->PATH), nil, nil); styx->init(); styxservers->init(styx); nametree->init(); (tree, treeop) := nametree->start(); tree.create(big Qdir, dir(".", Sys->DMDIR|8r555, Qdir)); tree.create(big Qdir, dir("users", 8r444, Qusers)); tree.create(big Qdir, dir("msgs", 8r666, Qmsgs)); p := array [2] of ref Sys->FD; if (sys->pipe(p) < 0){ tree.quit(); return (sys->sprint("cannot create pipe: %r"), nil, nil); } nextmsg = ref Msg (0, nil, nil, nil); (tc, srv) = Styxserver.new(p[1], Navigator.new(treeop), big Qdir); spawn chatsrv(tree); return (nil, "/", p[0]); } chatsrv(tree: ref Tree) { while((tmsg := <-tc) != nil){ pick tm := tmsg { Readerror => break; Flush => cancelpending(tm.tag); srv.reply(ref Rmsg.Flush(tm.tag)); Open => c := srv.open(tm); if (c == nil) break; if (int c.path == Qmsgs){ newmsgclient(tm.fid, c.uname); #root[0].qid.vers++; # TO DO } Read => c := srv.getfid(tm.fid); if (c == nil || !c.isopen) { srv.reply(ref Rmsg.Error(tm.tag, Styxservers->Ebadfid)); break; } case int c.path { Qdir => srv.read(tm); Qmsgs => mc := getmsgclient(tm.fid); if (mc == nil) { srv.reply(ref Rmsg.Error(tm.tag, "internal error -- lost client")); continue; } tm.offset = big 0; msg := getnextmsg(mc); if (msg == nil) { if(mc.pending != nil) srv.reply(ref Rmsg.Error(tm.tag, "read already pending")); else mc.pending = tm; continue; } srv.reply(styxservers->readstr(tm, msg)); Qusers => srv.reply(styxservers->readstr(tm, usernames())); * => srv.reply(ref Rmsg.Error(tm.tag, "phase error -- bad path")); } Write => c := srv.getfid(tm.fid); if (c == nil || !c.isopen) { srv.reply(ref Rmsg.Error(tm.tag, Styxservers->Ebadfid)); continue; } if (int c.path != Qmsgs) { srv.reply(ref Rmsg.Error(tm.tag, Styxservers->Eperm)); continue; } writemsgclients(tm.fid, c.uname, string tm.data); srv.reply(ref Rmsg.Write(tm.tag, len tm.data)); Clunk => c := srv.clunk(tm); if (c != nil && int c.path == Qmsgs){ closemsgclient(tm.fid); # root[0].qid.vers++; # TO DO } * => srv.default(tmsg); } } tree.quit(); sys->print("chatsrv exit\n"); } Msg: adt { fromfid: int; from: string; msg: string; next: cyclic ref Msg; }; Msgclient: adt { fid: int; name: string; nextmsg: ref Msg; pending: ref Tmsg.Read; next: cyclic ref Msgclient; }; nextmsg: ref Msg; msgclients: ref Msgclient; usernames(): string { s := ""; for (c := msgclients; c != nil; c = c.next) s += c.name+"\n"; return s; } newmsgclient(fid: int, name: string) { writemsgclients(fid, nil, "+++ " + name + " has arrived"); msgclients = ref Msgclient(fid, name, nextmsg, nil, msgclients); } getmsgclient(fid: int): ref Msgclient { for (c := msgclients; c != nil; c = c.next) if (c.fid == fid) return c; return nil; } cancelpending(tag: int) { for (c := msgclients; c != nil; c = c.next) if((tm := c.pending) != nil && tm.tag == tag){ c.pending = nil; break; } } closemsgclient(fid: int) { prev: ref Msgclient; s := ""; for (c := msgclients; c != nil; c = c.next) { if (c.fid == fid) { if (prev == nil) msgclients = c.next; else prev.next = c.next; s = "--- " + c.name + " has left"; break; } prev = c; } if (s != nil) writemsgclients(fid, nil, s); } writemsgclients(fromfid: int, from: string, msg: string) { nm := ref Msg(0, nil, nil, nil); nextmsg.fromfid = fromfid; nextmsg.from = from; nextmsg.msg = msg; nextmsg.next = nm; for (c := msgclients; c != nil; c = c.next) { if (c.pending != nil) { s := msgtext(c, nextmsg); srv.reply(styxservers->readstr(c.pending, s)); c.pending = nil; c.nextmsg = nm; } } nextmsg = nm; } getnextmsg(mc: ref Msgclient): string { # uncomment next two lines to eliminate queued messages to self # while(mc.nextmsg.next != nil && mc.nextmsg.fromfid == mc.fid) # mc.nextmsg = mc.nextmsg.next; if ((m := mc.nextmsg).next != nil){ mc.nextmsg = m.next; return msgtext(mc, m); } return nil; } msgtext(mc: ref Msgclient, m: ref Msg): string { prefix := ""; if (m.from != nil) { # not a system message if (mc.fid == m.fromfid) prefix = "<you>: "; else prefix = m.from + ": "; } return prefix + m.msg; }