io.event/protocol.lisp

   1 ;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Indent-tabs-mode: NIL -*-
   2 ;;;
   3 ;;; protocol.lisp --- Protocol classes and generic functions.
   4 ;;;
   5 ;;; Copyright (C) 2007, Stelian Ionescu  <sionescu@common-lisp.net>
   6 ;;; Copyright (C) 2007, Luis Oliveira  <loliveira@common-lisp.net>
   7 ;;;
   8 ;;; This code is free software; you can redistribute it and/or
   9 ;;; modify it under the terms of the version 2.1 of
  10 ;;; the GNU Lesser General Public License as published by
  11 ;;; the Free Software Foundation, as clarified by the
  12 ;;; preamble found here:
  13 ;;;     http://opensource.franz.com/preamble.html
  14 ;;;
  15 ;;; This program is distributed in the hope that it will be useful,
  16 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;;; GNU General Public License for more details.
  19 ;;;
  20 ;;; You should have received a copy of the GNU Lesser General
  21 ;;; Public License along with this library; if not, write to the
  22 ;;; Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  23 ;;; Boston, MA 02110-1301, USA
  24
  25 (in-package :io.event)
  26
  27 ;;;; Base Protocol Class
  28
  29 ;;; Calling it IO-PROTOCOL in order to avoid clashing with
  30 ;;; the SOCKETS:PROTOCOL class.
  31 (defclass io-protocol ()
  32   ((transport :initarg :transport :accessor transport-of))
  33   (:documentation ""))
  34
  35 ;;; What would the semantics for these GFs be?  Namely, how would
  36 ;;; ON-PROTOCOL-START differ from INITIALIZE-INSTANCE?
  37
  38 ;; (defgeneric on-protocol-start (protocol))
  39 ;; (defgeneric on-protocol-stop (protocol))
  40
  41 ;;;; Stream Protocol
  42
  43 (defclass stream-protocol (io-protocol)
  44   ()
  45   (:documentation ""))
  46
  47 ;;; These generic functions all take a TRANSPORT argument because a
  48 ;;; PROTOCOL may need to deal with multiple TRANSPORTS (per
  49 ;;; connection).  FTP would be an example of such a PROTOCOL.
  50
  51 (defgeneric on-connection-made (protocol transport)
  52   (:documentation "")
  53   ;; default empty method
  54   (:method ((sp stream-protocol) transport)
  55     (declare (ignore transport))
  56     (values)))
  57
  58 (defgeneric on-connection-lost (protocol transport reason)
  59   (:documentation "")
  60   ;; default empty method
  61   (:method ((sp stream-protocol) transport reason)
  62     (declare (ignore transport reason))
  63     (values)))
  64
  65 (defgeneric on-connection-end (protocol transport)
  66   (:documentation "")
  67   ;; default empty method
  68   (:method ((sp stream-protocol) transport)
  69     (declare (ignore transport))
  70     (values)))
  71
  72 (defgeneric on-data-received (protocol transport data)
  73   (:documentation "")
  74   ;; default empty method, though perhaps we should make it issue a
  75   ;; warning, since it's probably a good bet that we want to do
  76   ;; something with the data we receive.
  77   (:method ((sp stream-protocol) transport data)
  78     (declare (ignore transport data))
  79     (values)))
  80
  81 ;;;; Datagram Protocol
  82
  83 (defclass datagram-protocol (io-protocol)
  84   ()
  85   (:documentation ""))
  86
  87 (defgeneric on-datagram-received (protocol transport datagram address port)
  88   (:documentation "")
  89   ;; default empty method.  Again, same issue as with ON-DATA-RECEIVED.
  90   (:method ((dp datagram-protocol) transport datagram address port)
  91     (declare (ignore transport datagram address port))
  92     (values)))
  93
  94 ;;;; Debug Mixins
  95
  96 ;;; This seemed like a good idea at first but so far it's less useful
  97 ;;; than plain TRACE.
  98
  99 (defclass protocol-debug-mixin ()
 100   ()
 101   (:documentation ""))
 102
 103 (defmethod on-connection-made :before ((p protocol-debug-mixin) protocol)
 104   (declare (ignore protocol))
 105   (format *debug-io* "~&Connection made: ~S~%" p))
 106
 107 (defmethod on-connection-end :after ((p protocol-debug-mixin) protocol)
 108   (declare (ignore protocol))
 109   (format *debug-io* "~&Connection end: ~S~%" p))
 110
 111 (defmethod on-data-received :before ((p protocol-debug-mixin) protocol data)
 112   (declare (ignore protocol))
 113   (format *debug-io* "~&Data received: ~A bytes~%" (length data)))
 114
 115 #-(and)
 116 (defun debug-protocols ()
 117   (trace on-data-received
 118          on-transport-writable
 119          on-transport-readable
 120          on-transport-error
 121          on-connection-made
 122          on-connection-end))