implement ButtonServer; include "sys.m";sys : Sys;include "draw.m";include "styx.m";styx: Styx;Rmsg, Tmsg: import styx;include "styxservers.m";styxservers: Styxservers;Styxserver, Navigator: import styxservers;nametree: Nametree;Tree: import nametree;include "cfg.m";cfg: Cfg;include "arg.m";arg : Arg; cfgfile := "/etc/buttonserver.cfg";mntflg := Sys->MBEFORE;mntpt := "/dev";Qroot, Qbuttons : con big iota; ButtonServer: module {	init: fn(nil: ref Draw->Context, args: list of string);}; Reader: adt {	msgs: chan of ref Tmsg.Read;	fid: ref Styxservers->Fid;	data: chan of string;}; MAX_READERS : con 1024; readers := array [MAX_READERS] of Reader; init(nil: ref Draw->Context, args: list of string){	sys = load Sys Sys->PATH;	styx = load Styx Styx->PATH;	styx->init();	styxservers = load Styxservers Styxservers->PATH;	styxservers->init(styx);	nametree = load Nametree Nametree->PATH;	nametree->init();	arg = load Arg Arg->PATH;	arg->init(args);	while((c := arg->opt()) != 0) {		case c {		'c' => cfgfile = arg->arg();		* => sys->print("unrecognized option %c\n", c);		}	}	cfg = load Cfg Cfg->PATH;	if(cfg->init(cfgfile) != "") {		raise sys->sprint("could not access configuration file %s", cfgfile);	} 	for(i := 0; i < MAX_READERS; i++) {		readers[i].fid = nil;	} 	spawn read_events(); 	styxpipe := array [2] of ref Sys->FD;	sys->pipe(styxpipe);	(tree, treeop) := nametree->start();	tree.create(Qroot, dir(".", 8r555|Sys->DMDIR, Qroot));	tree.create(Qroot, dir("buttons", 8r666, Qbuttons));	(tchan, srv) := Styxserver.new(styxpipe[0], Navigator.new(treeop), Qroot);	# sys->mount will never return if we call it directly here	spawn mounter(styxpipe[1]); 	while((gm := <- tchan) != nil) {		pick m := gm {			Read =>				(fid, err) := srv.canread(m);				if(fid == nil) {					sys->print("error getting fid: %s\n", err);				}				if(fid.path == Qbuttons) {					reader := get_reader(fid, srv);					deliver_msg(reader, m);				} else {					srv.default(gm);				}			Clunk =>				fid := srv.clunk(m);				if(fid != nil && fid.path == Qbuttons) {					free_reader(fid);				}											* =>						srv.default(gm);		}	}	tree.quit();} read_events(){	fd := sys->open("/dev/events", sys->OREAD);	for(;;) {		newstr : string;		buf := array[64] of byte;		n := sys->read(fd, buf, len buf);		buf = buf[:n];		str := string buf;		for(i := 0; i < MAX_READERS; i++) {			if(readers[i].fid != nil) {				reader := readers[i];				reader.data <-= str;			}		}	}} mounter(styxfd : ref Sys->FD){	if(sys->mount(styxfd, nil, mntpt, mntflg, nil) < 0) {		sys->print("fail: ButtonServer mount failed: %r\n");	}} dir(name: string, perm: int, qid: big): Sys->Dir{	d := sys->zerodir;	d.name = name;	d.uid = "me";	d.gid = "me";	d.qid.path = qid;	if (perm & Sys->DMDIR)		d.qid.qtype = Sys->QTDIR;	else		d.qid.qtype = Sys->QTFILE;	d.mode = perm;	return d;} get_reader(fid: ref Styxservers->Fid, srv: ref Styxserver) : Reader{	for(i := 0; i < MAX_READERS; i++) {		if(readers[i].fid == fid) {			return readers[i];		}	} 	# reader was not found, create new entry	for(i = 0; i < MAX_READERS; i++) {		if(readers[i].fid == nil) {			readers[i].fid = fid;			readers[i].msgs = chan of ref Tmsg.Read;			readers[i].data = chan of string;			spawn read_msgs(readers[i], srv);			return readers[i];		}	}	raise(sys->sprint("not enough space for new reader"));	return readers[0];} deliver_msg(reader: Reader, msg: ref Tmsg.Read){	reader.msgs <-= msg;} read_msgs(reader: Reader, srv: ref Styxserver){	for(;;) {		str: string;		msg := <- reader.msgs;		while(1) {			str = <- reader.data;			str = interpret(str);			if(str != "") {				reply := ref Rmsg.Read(msg.tag, nil);				reply.data = array of byte str;				srv.reply(reply);				break;			}		}	}} interpret(event : string) : string{	str: string;	a: ref Cfg->Record;	lst := cfg->lookup(event[:len event - 1]);	if(lst == nil) return "";	(str, a) = hd lst;	if(str == nil) str = "";	return str + "\n";} free_reader(fid: ref Styxservers->Fid){	for(i := 0; i < MAX_READERS; i++) {		if(readers[i].fid == fid) {			readers[i].fid = nil;		}	}}