1 files changed, 190 insertions, 0 deletions
diff --git a/appl/lib/plumbmsg.b b/appl/lib/plumbmsg.b
new file mode 100644
index 00000000..ef9928e1
--- /dev/null
+++ b/appl/lib/plumbmsg.b
@@ -0,0 +1,190 @@
+implement Plumbmsg;
+
+include "sys.m";
+	sys: Sys;
+
+include "plumbmsg.m";
+
+input: ref Sys->FD;
+port: ref Sys->FD;
+portname: string;
+maxdatasize: int;
+
+init(doinput: int, rcvport: string, maxdata: int): int
+{
+	sys = load Sys Sys->PATH;
+
+	if(!doinput && rcvport == nil)	# server, not client
+		return 1;
+	input = sys->open("/chan/plumb.input", Sys->OWRITE);
+	if(input == nil)
+		return -1;
+	if(rcvport == nil)	# sending messages but never receiving them
+		return 1;
+	port = sys->open("/chan/plumb."+rcvport, Sys->OREAD);
+	if(port == nil){
+		input = nil;
+		return -1;
+	}
+	maxdatasize = maxdata;
+	portname = rcvport;
+	msg := ref Msg;
+	msg.src = portname;
+	msg.dst = "plumb";
+	msg.kind = "text";
+	msg.data = array of byte "start";
+	if(msg.send() < 0){
+		port = nil;
+		input = nil;
+		return -1;
+	}
+	return 1;
+}
+
+shutdown()
+{
+	msg := ref Msg;
+	msg.src = portname;
+	msg.dst = "plumb";
+	msg.kind = "text";
+	msg.data = array of byte "stop";
+	msg.send();
+}
+
+Msg.send(msg: self ref Msg): int
+{
+	hdr :=
+		msg.src+"\n"+
+		msg.dst+"\n"+
+		msg.dir+"\n"+
+		msg.kind+"\n"+
+		msg.attr+"\n"+
+		string len msg.data+"\n";
+	ahdr := array of byte hdr;
+	b := array[len ahdr+len msg.data] of byte;
+	b[0:] = ahdr;
+	b[len ahdr:] = msg.data;
+	return sys->write(input, b, len b);
+}
+
+Msg.recv(): ref Msg
+{
+	b := array[maxdatasize+1000] of byte;
+	n := sys->read(port, b, len b);
+	if(n <= 0)
+		return nil;
+	return Msg.unpack(b[0:n]);
+}
+
+Msg.unpack(b: array of byte): ref Msg
+{
+	(hdr, data) := unpack(b, 6);
+	if(hdr == nil)
+		return nil;
+
+	msg := ref Msg;
+	msg.src = hdr[0];
+	msg.dst = hdr[1];
+	msg.dir = hdr[2];
+	msg.kind = hdr[3];
+	msg.attr = hdr[4];
+	msg.data = data;
+
+	return msg;
+}
+
+Msg.pack(msg: self ref Msg): array of byte
+{
+	hdr :=
+		msg.src+"\n"+
+		msg.dst+"\n"+
+		msg.dir+"\n"+
+		msg.kind+"\n"+
+		msg.attr+"\n"+
+		string len msg.data+"\n";
+	ahdr := array of byte hdr;
+	b := array[len ahdr+len msg.data] of byte;
+	b[0:] = ahdr;
+	b[len ahdr:] = msg.data;
+	return b;
+}
+
+# unpack message from array of bytes.  last string in message
+# is number of bytes in data portion of message
+unpack(b: array of byte, ns: int): (array of string, array of byte)
+{
+	i := 0;
+	a := array[ns] of string;
+	for(n:=0; n<ns; n++){
+		(i, a[n]) = unpackstring(b, i);
+		if(i < 0)
+			return (nil, nil);
+	}
+	nb := int a[ns-1];
+	if((len b)-i != nb){
+		sys->print("unpack: bad message format: wrong nbytes\n");
+		return (nil, nil);
+	}
+	# copy data so b can be reused or freed
+	data := array[nb] of byte;
+	data[0:] = b[i:];
+	return (a, data);
+}
+
+unpackstring(b: array of byte, i: int): (int, string)
+{
+	starti := i;
+	while(i < len b){
+		if(b[i] == byte '\n')
+			return (i+1, string b[starti:i]);
+		i++;
+	}
+	return (-1, nil);
+}
+
+string2attrs(s: string): list of ref Attr
+{
+	(nil, pairs) := sys->tokenize(s, "\t");
+	if(pairs == nil)
+		return nil;
+	attrs: list of ref Attr;
+	while(pairs != nil){
+		pair := hd pairs;
+		pairs = tl pairs;
+		a := ref Attr;
+		for(i:=0; i<len pair; i++)
+			if(pair[i] == '='){
+				a.name = pair[0:i];
+				if(++i < len pair)
+					a.val = pair[i:];
+				break;
+			}
+		attrs = a :: attrs;
+	}
+	return attrs;
+}
+
+attrs2string(l: list of ref Attr): string
+{
+	s := "";
+	while(l != nil){
+		a := hd l;
+		l = tl l;
+		if(s == "")
+			s = a.name + "=" + a.val;
+		else
+			s += "\t" + a.name + "=" + a.val;
+	}
+	return s;
+}
+
+lookup(attrs: list of ref Attr, name: string): (int, string)
+{
+	while(attrs != nil){
+		a := hd attrs;
+		attrs = tl attrs;
+		if(a.name == name)
+			return (1, a.val);
+	}
+	return (0, nil);
+}