allow callback-able objects to share callbacks

lib/httpx/callbacks.rb

@@ -17,9 +17,14 @@ module HTTPX
       callbacks(type).delete_if { |pr| pr[*args] == :delete }
     end
 
-    private
+    protected
 
-    def callbacks(type)
+    def inherit_callbacks(callbackable)
+      @callbacks = callbackable.callbacks
+    end
+
+    def callbacks(type=nil)
+      return @callbacks unless type
       @callbacks ||= Hash.new { |h, k| h[k] = [] }
       @callbacks[type]
     end

lib/httpx/channel.rb

@@ -32,6 +32,7 @@ module HTTPX
     extend Forwardable
     include Registry
     include Loggable
+    include Callbacks
 
     require "httpx/channel/http2"
     require "httpx/channel/http1"
@@ -39,7 +40,7 @@ module HTTPX
     BUFFER_SIZE = 1 << 14
 
     class << self
-      def by(uri, options, &blk)
+      def by(uri, options)
         io = case uri.scheme
         when "http"
           IO.registry("tcp").new(uri.host, uri.port, options)
@@ -48,7 +49,7 @@ module HTTPX
         else
           raise Error, "#{uri.scheme}: unrecognized channel"
         end
-        new(io, options, &blk)
+        new(io, options)
       end
     end
 
@@ -56,14 +57,13 @@ module HTTPX
 
     def_delegator :@write_buffer, :empty?
 
-    def initialize(io, options, &on_response)
+    def initialize(io, options)
       @io = io
       @options = Options.new(options)
       @window_size = @options.window_size
       @read_buffer = "".b
       @write_buffer = Buffer.new(BUFFER_SIZE)
       @pending = []
-      @on_response = on_response
     end
 
     def match?(uri)
@@ -161,7 +161,7 @@ module HTTPX
 
     def build_parser(protocol=@io.protocol)
       parser = registry(protocol).new(@write_buffer, @options)
-      parser.on(:response, &@on_response)
+      parser.inherit_callbacks(self)
       parser.on(:close) { throw(:close, self) }
       parser
     end

lib/httpx/connection.rb

@@ -38,8 +38,8 @@ module HTTPX
       end
     end
 
-    def build_channel(uri, &on_response)
-      channel = Channel.by(uri, @options, &on_response)
+    def build_channel(uri)
+      channel = Channel.by(uri, @options)
       register_channel(channel)
       channel
     end

lib/httpx/plugins/proxy/http.rb

@@ -44,7 +44,7 @@ module HTTPX
                 @parser = nil
               when :idle
                 @parser = ProxyParser.new(@write_buffer, @options)
-                @parser.on(:response, &@on_response)
+                @parser.inherit_callbacks(self)
                 @parser.on(:close) { throw(:close, self) }
               else
                 return