extract event emitter

4 files changed, 22 insertions, 24 deletions

diff --git a/lib/plum.rb b/lib/plum.rb
index d37a22c..59e6a9e 100644
--- a/lib/plum.rb
+++ b/lib/plum.rb
@@ -3,6 +3,7 @@ require "socket"
 require "plum/version"
 require "plum/error"
 require "plum/binary_string"
+require "plum/event_emitter"
 require "plum/hpack/constants"
 require "plum/hpack/huffman"
 require "plum/hpack/context"
diff --git a/lib/plum/event_emitter.rb b/lib/plum/event_emitter.rb
new file mode 100644
index 0000000..feebfa1
--- /dev/null
+++ b/lib/plum/event_emitter.rb
@@ -0,0 +1,19 @@
+module Plum
+  module EventEmitter
+    # Registers an event handler to specified event. An event can have multiple handlers.
+    # @param name [String] The name of event.
+    # @yield Gives event-specific parameters.
+    def on(name, &blk)
+      callbacks[name] << blk
+    end
+
+    private
+    def callback(name, *args)
+      callbacks[name].each {|cb| cb.call(*args) }
+    end
+
+    def callbacks
+      @callbacks ||= Hash.new {|hash, key| hash[key] = [] }
+    end
+  end
+end
diff --git a/lib/plum/server_connection.rb b/lib/plum/server_connection.rb
index 18df556..12bbe4f 100644
--- a/lib/plum/server_connection.rb
+++ b/lib/plum/server_connection.rb
@@ -2,6 +2,7 @@ using Plum::BinaryString
 
 module Plum
   class ServerConnection
+    include EventEmitter
     include FlowControl
     include ServerConnectionHelper
 
@@ -24,7 +25,6 @@ module Plum
       @socket = socket
       @local_settings = Hash.new {|hash, key| DEFAULT_SETTINGS[key] }.merge!(local_settings)
       @remote_settings = Hash.new {|hash, key| DEFAULT_SETTINGS[key] }
-      @callbacks = Hash.new {|hash, key| hash[key] = [] }
       @buffer = "".force_encoding(Encoding::BINARY)
       @streams = {}
       @state = :waiting_connetion_preface
@@ -34,13 +34,6 @@ module Plum
                               recv: @local_settings[:initial_window_size])
     end
 
-    # Registers an event handler to specified event. An event can have multiple handlers.
-    # @param name [String] The name of event.
-    # @yield Gives event-specific parameters.
-    def on(name, &blk)
-      @callbacks[name] << blk
-    end
-
     # Starts communication with the peer. It blocks until the socket is closed, or reaches EOF.
     def start
       settings(@local_settings)
@@ -107,10 +100,6 @@ module Plum
     end
 
     private
-    def callback(name, *args)
-      @callbacks[name].each {|cb| cb.call(*args) }
-    end
-
     def send_immediately(frame)
       callback(:send_frame, frame)
       @socket.write(frame.assemble)
diff --git a/lib/plum/stream.rb b/lib/plum/stream.rb
index ad0bfe6..67e2550 100644
--- a/lib/plum/stream.rb
+++ b/lib/plum/stream.rb
@@ -2,6 +2,7 @@ using Plum::BinaryString
 
 module Plum
   class Stream
+    include EventEmitter
     include FlowControl
     include StreamHelper
 
@@ -14,7 +15,6 @@ module Plum
       @id = id
       @state = state
       @continuation = []
-      @callbacks = Hash.new {|hash, key| hash[key] = [] }
 
       initialize_flow_control(send: @connection.remote_settings[:initial_window_size],
                               recv: @connection.local_settings[:initial_window_size])
@@ -69,18 +69,7 @@ module Plum
                                  payload: data)
     end
 
-    # Registers an event handler to specified event. An event can have multiple handlers.
-    # @param name [String] The name of event.
-    # @yield Gives event-specific parameters.
-    def on(name, &blk)
-      @callbacks[name] << blk
-    end
-
     private
-    def callback(name, *args)
-      @callbacks[name].each {|cb| cb.call(*args) }
-    end
-
     def send_immediately(frame)
       callback(:send_frame, frame)
       @connection.send(frame)