1 files changed, 118 insertions, 0 deletions
diff --git a/lib/plum/server.rb b/lib/plum/server.rb
new file mode 100644
index 0000000..1551985
--- /dev/null
+++ b/lib/plum/server.rb
@@ -0,0 +1,118 @@
+module Plum
+  class Server
+    CLIENT_CONNECTION_PREFACE = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
+    
+    attr_reader :hpack_encoder, :hpack_decoder
+    attr_accessor :on_stream, :on_frame, :on_send_frame
+
+    def initialize(socket, settings = nil)
+      @socket = socket
+      @settings = nil
+      @buffer = ""
+      @streams = {}
+      @state = :waiting_for_connetion_preface
+      @last_stream_id = 0
+      @hpack_decoder = HPACK::Decoder.new(65536)
+      @hpack_encoder = HPACK::Encoder.new(65536)
+    end
+
+    def send(frame)
+      on(:send_frame, frame)
+      @socket.write(frame.assemble)
+    end
+
+    def start
+      settings_payload = @settings
+      settings_frame = Frame.new(type: :settings,
+                                 stream_id: 0,
+                                 payload: settings_payload)
+      send(settings_frame)
+
+      until @socket.eof?
+        @buffer << @socket.readpartial(1024)
+        process
+      end
+    rescue Plum::ConnectionError => e
+      on(:connection_error, e)
+      data = [@last_stream_id & ~(1 << 31)].pack("N")
+      data << [e.http2_error_code].pack("N")
+      data << ""
+      error = Frame.new(type: :goaway,
+                        stream_id: 0,
+                        payload: data)
+      send(error)
+    end
+
+    def on(name, *args)
+      cb = instance_variable_get("@on_#{name}")
+      cb.call(*args) if cb
+    end
+
+    private
+    def process
+      if @state == :waiting_for_connetion_preface
+        return if @buffer.size < 24
+        if @buffer.slice!(0, 24) != CLIENT_CONNECTION_PREFACE
+          raise Plum::ConnectionError.new(:protocol_error) # (MAY) send GOAWAY. sending.
+        else
+          @state = :waiting_for_settings
+          # continue
+        end
+      end
+
+      while frame = Frame.parse!(@buffer)
+        on(:frame, frame)
+
+        if @state == :waiting_for_settings && frame.type != :settings
+          raise Plum::ConnectionError.new(:protocol_error)
+        end
+
+        if frame.stream_id == 0
+          process_control_frame(frame)
+        else
+          stream = @streams[frame.stream_id]
+          if stream
+            stream.on_frame(frame)
+          else
+            new_client_stream(frame)
+          end
+          @last_stream_id = frame.stream_id
+        end
+      end
+    end
+
+    def process_control_frame(frame)
+      case frame.type
+      when :settings
+        @state = :initialized if @state == :waiting_for_settings
+        process_settings(frame)
+      when :window_update
+      else
+        # TODO
+      end
+    end
+
+    def process_settings(frame)
+      # apply settings (MUST)
+      settings_ack = Frame.new(type: :settings, stream_id: 0x00, flags: [:ack])
+      send(settings_ack)
+    end
+    
+    def new_client_stream(frame)
+      if (frame.stream_id % 2 == 0) ||
+          (@streams.size > 0 && @streams.keys.last >= frame.stream_id)
+        raise Plum::ConnectionError.new(:protocol_error)
+      end
+
+      unless [:headers, :push_stream].include?(frame.type)
+        raise Plum::ConnectionError.new(:protocol_error)
+      end
+
+      @streams.select {|id, s| s.state == :idle }.each {|id, s| s.close }
+      stream = Stream.new(self, frame.stream_id)
+      @streams[frame.stream_id] = stream
+      on(:stream, stream)
+      stream.on_frame(frame)
+    end
+  end
+end