From: Matt S Trout <mst@shadowcat.co.uk>
Date: Thu, 19 Jul 2012 18:56:13 +0000 (+0000)
Subject: create ReadChannel object to allow moving Shere logic into connect
X-Git-Tag: v0.002002~6
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=12fb4a80d68ad14c18a35f60cc6d8a671f728ac9;p=scpubgit%2FObject-Remote.git

create ReadChannel object to allow moving Shere logic into connect
---

diff --git a/lib/Object/Remote/Connection.pm b/lib/Object/Remote/Connection.pm
index 556a4c2..21bcec4 100644
--- a/lib/Object/Remote/Connection.pm
+++ b/lib/Object/Remote/Connection.pm
@@ -21,29 +21,29 @@ has send_to_fh => (
   trigger => sub { $_[1]->autoflush(1) },
 );
 
-has receive_from_fh => (
+has read_channel => (
   is => 'ro', required => 1,
   trigger => sub {
-    my ($self, $fh) = @_;
+    my ($self, $ch) = @_;
     weaken($self);
-    Object::Remote->current_loop
-                  ->watch_io(
-                      handle => $fh,
-                      on_read_ready => sub { $self->_receive_data_from($fh) }
-                    );
+    $ch->on_line_call(sub { $self->_receive(@_) });
+    $ch->on_close_call(sub { $self->on_close->done(@_) });
   },
 );
 
-has on_close => (is => 'rw', default => sub { CPS::Future->new });
+has on_close => (
+  is => 'ro', default => sub { CPS::Future->new },
+  trigger => sub { 
+    my ($self, $f) = @_;
+    weaken($self);
+    $f->on_done(sub {
+      $self->_fail_outstanding("Connection lost: ".($f->get)[0]);
+    });
+  }
+);
 
 has child_pid => (is => 'ro');
 
-has ready_future => (is => 'lazy');
-
-sub _build_ready_future { CPS::Future->new }
-
-has _receive_data_buffer => (is => 'ro', default => sub { my $x = ''; \$x });
-
 has local_objects_by_id => (
   is => 'ro', default => sub { {} },
   coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
@@ -56,6 +56,14 @@ has remote_objects_by_id => (
 
 has outstanding_futures => (is => 'ro', default => sub { {} });
 
+sub _fail_outstanding {
+  my ($self, $error) = @_;
+  my $outstanding = $self->outstanding_futures;
+  $_->fail($error) for values %$outstanding;
+  %$outstanding = ();
+  return;
+}
+
 has _json => (
   is => 'lazy',
   handles => {
@@ -165,11 +173,6 @@ sub register_remote {
   return $remote;
 }
 
-sub await_ready {
-  my ($self) = @_;
-  await_future($self->ready_future);
-}
-
 sub send_free {
   my ($self, $id) = @_;
   delete $self->remote_objects_by_id->{$id};
@@ -207,8 +210,6 @@ sub send_discard {
 sub _send {
   my ($self, $to_send) = @_;
 
-  $self->await_ready;
-
   print { $self->send_to_fh } $self->_serialize($to_send)."\n";
 }
 
@@ -264,36 +265,6 @@ sub _deobjectify {
   return $data; # plain scalar
 }
 
-sub _receive_data_from {
-  my ($self, $fh) = @_;
-  my $rb = $self->_receive_data_buffer;
-  my $ready = $self->ready_future->is_ready;
-  my $len = sysread($fh, $$rb, 1024, length($$rb));
-  my $err = defined($len) ? '' : ": $!";
-  if (defined($len) and $len > 0) {
-    while ($$rb =~ s/^(.*)\n//) {
-      if ($ready) {
-        $self->_receive($1);
-      } else {
-        my $line = $1;
-        die "New remote container did not send Shere - got ${line}"
-          unless $line eq "Shere";
-        $self->ready_future->done;
-      }
-    }
-  } else {
-    Object::Remote->current_loop
-                  ->unwatch_io(
-                      handle => $self->receive_from_fh,
-                      on_read_ready => 1
-                    );
-    my $outstanding = $self->outstanding_futures;
-    $_->fail("Connection lost${err}") for values %$outstanding;
-    %$outstanding = ();
-    $self->on_close->done();
-  }
-}
-
 sub _receive {
   my ($self, $flat) = @_;
   warn "$$ <<< $flat\n" if $DEBUG;
@@ -347,16 +318,6 @@ sub _invoke {
   return;
 }
 
-sub DEMOLISH {
-  my ($self, $gd) = @_;
-  return if $gd;
-  Object::Remote->current_loop
-                ->unwatch_io(
-                    handle => $self->receive_from_fh,
-                    on_read_ready => 1
-                  );
-}
-
 1;
 
 =head1 NAME
diff --git a/lib/Object/Remote/Connector/STDIO.pm b/lib/Object/Remote/Connector/STDIO.pm
index ee34319..69ba95d 100644
--- a/lib/Object/Remote/Connector/STDIO.pm
+++ b/lib/Object/Remote/Connector/STDIO.pm
@@ -3,6 +3,7 @@ package Object::Remote::Connector::STDIO;
 use File::Spec;
 use IO::Handle;
 use Object::Remote::Connection;
+use Object::Remote::ReadChannel;
 use Moo;
 
 sub connect {
@@ -18,7 +19,7 @@ sub connect {
   open STDOUT, '>', File::Spec->devnull or die "Re-opening stdout: $!";
   return Object::Remote::Connection->new(
     send_to_fh => $stdout,
-    receive_from_fh => $stdin
+    read_channel => Object::Remote::ReadChannel->new(fh => $stdin)
   );
 }
 
diff --git a/lib/Object/Remote/Node.pm b/lib/Object/Remote/Node.pm
index 7190359..dc2563c 100644
--- a/lib/Object/Remote/Node.pm
+++ b/lib/Object/Remote/Node.pm
@@ -6,20 +6,13 @@ use Object::Remote;
 use CPS::Future;
 
 sub run {
-
   my $c = Object::Remote::Connector::STDIO->new->connect;
 
   $c->register_class_call_handler;
 
-  $c->ready_future->done;
-
   my $loop = Object::Remote->current_loop;
 
-  my $f = CPS::Future->new;
-
-  $f->on_ready(sub { $loop->want_stop });
-
-  $c->on_close($f);
+  $c->on_close->on_ready(sub { $loop->want_stop });
 
   print { $c->send_to_fh } "Shere\n";
 
diff --git a/lib/Object/Remote/ReadChannel.pm b/lib/Object/Remote/ReadChannel.pm
new file mode 100644
index 0000000..84b3270
--- /dev/null
+++ b/lib/Object/Remote/ReadChannel.pm
@@ -0,0 +1,57 @@
+package Object::Remote::ReadChannel;
+
+use CPS::Future;
+use Scalar::Util qw(weaken);
+use Moo;
+
+has fh => (
+  is => 'ro', required => 1,
+  trigger => sub {
+    my ($self, $fh) = @_;
+    weaken($self);
+    Object::Remote->current_loop
+                  ->watch_io(
+                      handle => $fh,
+                      on_read_ready => sub { $self->_receive_data_from($fh) }
+                    );
+  },
+);
+
+has on_close_call => (
+  is => 'rw', default => sub { sub {} },
+);
+
+has on_line_call => (is => 'rw');
+
+has _receive_data_buffer => (is => 'ro', default => sub { my $x = ''; \$x });
+
+sub _receive_data_from {
+  my ($self, $fh) = @_;
+  my $rb = $self->_receive_data_buffer;
+  my $len = sysread($fh, $$rb, 1024, length($$rb));
+  my $err = defined($len) ? '' : ": $!";
+  if (defined($len) and $len > 0) {
+    while (my $cb = $self->on_line_call and $$rb =~ s/^(.*)\n//) {
+      $cb->(my $line = $1);
+    }
+  } else {
+    Object::Remote->current_loop
+                  ->unwatch_io(
+                      handle => $self->fh,
+                      on_read_ready => 1
+                    );
+    $self->on_close_call->($err);
+  }
+}
+
+sub DEMOLISH {
+  my ($self, $gd) = @_;
+  return if $gd;
+  Object::Remote->current_loop
+                ->unwatch_io(
+                    handle => $self->fh,
+                    on_read_ready => 1
+                  );
+}
+
+1;
diff --git a/lib/Object/Remote/Role/Connector.pm b/lib/Object/Remote/Role/Connector.pm
index 16f0d52..cc8684b 100644
--- a/lib/Object/Remote/Role/Connector.pm
+++ b/lib/Object/Remote/Role/Connector.pm
@@ -1,15 +1,47 @@
 package Object::Remote::Role::Connector;
 
 use Module::Runtime qw(use_module);
+use Object::Remote::Future;
 use Moo::Role;
 
 requires '_open2_for';
 
 sub connect {
   my $self = shift;
-  my %args;
-  @args{qw(send_to_fh receive_from_fh child_pid)} = $self->_open2_for(@_);
-  return use_module('Object::Remote::Connection')->new(\%args);
+  my ($send_to_fh, $receive_from_fh, $child_pid) = $self->_open2_for(@_);
+  my $channel = use_module('Object::Remote::ReadChannel')->new(
+    fh => $receive_from_fh
+  );
+  return future {
+    my $f = shift;
+    $channel->on_line_call(sub {
+      if ($_[0] eq "Shere") {
+        $f->done(
+          use_module('Object::Remote::Connection')->new(
+            send_to_fh => $send_to_fh,
+            read_channel => $channel,
+            child_pid => $child_pid,
+          )
+        );
+      } else {
+        $f->fail("Expected Shere from remote but received: $_[0]");
+      }
+      undef($channel);
+    });
+    $channel->on_close_call(sub {
+      $f->fail("Channel closed without seeing Shere: $_[0]");
+      undef($channel);
+    });
+    Object::Remote->current_loop
+                  ->watch_time(
+                      after => 5,
+                      code => sub {
+                        $f->fail("Connection timed out") unless $f->is_ready;
+                        undef($channel);
+                      }
+                    );
+    $f;
+  }
 }
 
 1;