Remove 'reply' argument + added return-path functionality

The 'reply' thing is more typing overhead than it is worth. Especially
since the return-path functionality uses Perl's GC to automatically
close the return-path when no sessions have a reference to the object
anymore. A session can simply not read the second argument of the
tuple-callback to close the return path. (This does mean that the path
will stay open for as long as the function is running, but that doesn't
matter anyway in a single-threaded application.)

1 files changed, 41 insertions, 11 deletions

diff --git a/Tanja.pm b/Tanja.pm
index 1062cda..d62a30d 100644
--- a/Tanja.pm
+++ b/Tanja.pm
@@ -47,24 +47,25 @@ sub link {
 
 
 # Send a tuple to the network.
-# Arguments: [ tuple ], $return_cb
+# Arguments: [ tuple ], $return_cb->([tuple] or ())
+# TODO: Some way to indicate that the session isn't interested in replies anymore?
 sub send {
 	my($s, $t, $cb) = @_;
-	# TODO: fix return path
+	my $ret = Tanja::ReturnPath->_new($cb);
 	for my $reg (grep Tanja::match($_->[0], $t), values %{$s->{pat}}) {
 		AnyEvent::postpone {
-			$reg->[2]->($t, undef);
+			$reg->[1]->($t, $ret);
 		}
 	}
 }
 
 
 sub _register {
-	my($s, $pat, $reply, $cb) = @_;
+	my($s, $pat, $cb) = @_;
 	my $id = $s->{lastid};
 	# Explicitely wrap around long before 2^31, to avoid having Perl turn the ID into a float.
 	++$id >= 1<<30 and $id = 1 while $s->{pat}{$id};
-	$s->{pat}{$id} = [ $pat, $reply, $cb ];
+	$s->{pat}{$id} = [ $pat, $cb ];
 	$s->{lastid} = $id;
 	return $id;
 }
@@ -94,15 +95,14 @@ sub new {
 
 
 # Register for a pattern
-#   Args: [ pattern ], willreply, callback
+#   Args: [ pattern ], callback
 #   Returns: $id, for use with unreg()
 # Callback:
 #   Args: [ tuple ], $return_path
-#   Returns: (ignored)
 sub reg {
-	my($s, $pat, $reply, $cb) = @_;
+	my($s, $pat, $cb) = @_;
 	my $id;
-	$id = $s->{server}->_register($pat, $reply, sub { $s->{pat}{$id} && $cb->(@_) });
+	$id = $s->{server}->_register($pat, sub { $s->{pat}{$id} && $cb->(@_) });
 	$s->{pat}{$id} = 1;
 	return $id;
 }
@@ -118,9 +118,9 @@ sub unreg {
 
 # For convenience. Same as ->reg(), but unregisters automatically after one call.
 sub reg_once {
-	my($s, $pat, $reply, $cb) = @_;
+	my($s, $pat, $cb) = @_;
 	my $id;
-	$id = $s->reg($pat, $reply, sub { $s->unreg($id); $cb->(@_) });
+	$id = $s->reg($pat, sub { $s->unreg($id); $cb->(@_) });
 	return $id;
 }
 
@@ -138,6 +138,36 @@ sub close {
 	$s->{pat} = {};
 }
 
+
+package Tanja::ReturnPath;
+
+use strict;
+use warnings;
+use AnyEvent;
+
+sub _new {
+	my($own, $cb) = @_;
+	return bless \$cb, $own;
+}
+
+sub null {
+	my $cb = shift;
+	return !$$cb;
+}
+
+sub reply {
+	my($cb, $t) = @_;
+	$$cb && AnyEvent::postpone { $$cb->($t); };
+}
+
+sub DESTROY {
+	my $cb = shift;
+	my $c = $$cb;
+	$c && AnyEvent::postpone { $c->() };
+	undef $$cb;
+}
+
 1;
+
 # vim:noet:sw=4:ts=4