channel for untagged server response: add optional error data (#28)

Github Issue: #28 Add optional error data to inspect the status of the running server.
y10k · Nov 21, 2019 · 771881e · 771881e
1 parent 3c6d5d5
commit 771881e
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Showing 2 changed files with 30 additions and 5 deletions.
diff --git a/lib/rims/channel.rb b/lib/rims/channel.rb
@@ -1,6 +1,18 @@
 # -*- coding: utf-8 -*-
 
 module RIMS
+  class ServerResponseChannelError < Error
+  end
+
+  class ServerResponseChannelAttachError < ServerResponseChannelError
+  end
+
+  class ServerResponseChannelDetachError < ServerResponseChannelError
+  end
+
+  class ServerResponseChannelPublishError < ServerResponseChannelError
+  end
+
   class ServerResponseChannel
     def initialize
       @mutex = Thread::Mutex.new
@@ -16,7 +28,9 @@ def make_pub_sub_pair(mbox_id)
     def attach(sub)
       @mutex.synchronize{
         @channel[sub.mbox_id] ||= {}
-        (@channel[sub.mbox_id].key? sub.pub_sub_pair_key) and raise ArgumentError, 'conflicted subscriber.'
+        if (@channel[sub.mbox_id].key? sub.pub_sub_pair_key) then
+          raise ServerResponseChannelAttachError.new('conflicted subscriber.', channel: self, subscriber: sub)
+        end
         @channel[sub.mbox_id][sub.pub_sub_pair_key] = sub
       }
 
@@ -30,8 +44,13 @@ def attach(sub)
     #   - ServerResponseSubscriber#detach
     def detach(sub)
       @mutex.synchronize{
-        ((@channel.key? sub.mbox_id) && (@channel[sub.mbox_id].key? sub.pub_sub_pair_key)) or raise ArgumentError, 'unregistered pub-sub pair.'
-        (@channel[sub.mbox_id][sub.pub_sub_pair_key] == sub) or raise 'internal error: mismatched subscriber.'
+        unless ((@channel.key? sub.mbox_id) && (@channel[sub.mbox_id].key? sub.pub_sub_pair_key)) then
+          raise ServerResponseChannelDetachError.new('unregistered pub-sub pair.', channel: self, subscriber: sub)
+        end
+
+        unless (@channel[sub.mbox_id][sub.pub_sub_pair_key] == sub) then
+          raise ServerResponseChannelDetachError.new('internal error: mismatched subscriber.', channel: self, subscribe: sub)
+        end
 
         @channel[sub.mbox_id].delete(sub.pub_sub_pair_key)
         if (@channel[sub.mbox_id].empty?) then
@@ -74,7 +93,12 @@ def pub_sub_pair_key
     end
 
     def publish(response_message)
-      @channel or raise 'detached publisher.'
+      unless (@channel) then
+        raise ServerResponseChannelPublishError.new('detached publisher.',
+                                                    publisher: self,
+                                                    pub_sub_pair_key: pub_sub_pair_key,
+                                                    message: response_message)
+      end
       @channel.publish(@mbox_id, pub_sub_pair_key, response_message)
       nil
     end

diff --git a/test/test_channel.rb b/test/test_channel.rb
@@ -55,7 +55,8 @@ def test_pub_sub_detach
       pub1.publish('msg1')
       pub2.publish('msg2')
 
-      error = assert_raise(RuntimeError) { pub3.publish('msg3') }
+      error = assert_raise(RIMS::ServerResponseChannelPublishError) { pub3.publish('msg3') }
+      pp error, error.optional_data if $DEBUG
       assert_match(/detached/, error.message)
 
       assert_equal(%w[ msg2 ], sub1.enum_for(:fetch).to_a)