misc/fuel/fuel-connection.el

   1 ;;; fuel-connection.el -- asynchronous comms with the fuel listener
   2
   3 ;; Copyright (C) 2008, 2009 Jose Antonio Ortega Ruiz
   4 ;; See http://factorcode.org/license.txt for BSD license.
   5
   6 ;; Author: Jose Antonio Ortega Ruiz <jao@gnu.org>
   7 ;; Keywords: languages, fuel, factor
   8 ;; Start date: Thu Dec 11, 2008 03:10
   9
  10 ;;; Comentary:
  11
  12 ;; Handling communications via a comint buffer running a factor
  13 ;; listener.
  14
  15 ;;; Code:
  16
  17 (require 'fuel-log)
  18 (require 'fuel-base)
  19
  20 (require 'comint)
  21 (require 'advice)
  22
  23 \f
  24 ;;; Default connection:
  25
  26 (make-variable-buffer-local
  27  (defvar fuel-con--connection nil))
  28
  29 (defun fuel-con--get-connection (buffer/proc)
  30   (if (processp buffer/proc)
  31       (fuel-con--get-connection (process-buffer buffer/proc))
  32     (with-current-buffer buffer/proc fuel-con--connection)))
  33
  34 \f
  35 ;;; Request and connection datatypes:
  36
  37 (defun fuel-con--connection-queue-request (c r)
  38   (let ((reqs (assoc :requests c)))
  39     (setcdr reqs (append (cdr reqs) (list r)))))
  40
  41 (defun fuel-con--make-request (str cont &optional sender-buffer)
  42   (list :fuel-connection-request
  43         (cons :id (random))
  44         (cons :string str)
  45         (cons :continuation cont)
  46         (cons :buffer (or sender-buffer (current-buffer)))))
  47
  48 (defsubst fuel-con--request-p (req)
  49   (and (listp req) (eq (car req) :fuel-connection-request)))
  50
  51 (defsubst fuel-con--request-id (req)
  52   (cdr (assoc :id req)))
  53
  54 (defsubst fuel-con--request-string (req)
  55   (cdr (assoc :string req)))
  56
  57 (defsubst fuel-con--request-continuation (req)
  58   (cdr (assoc :continuation req)))
  59
  60 (defsubst fuel-con--request-buffer (req)
  61   (cdr (assoc :buffer req)))
  62
  63 (defsubst fuel-con--request-deactivate (req)
  64   (setcdr (assoc :continuation req) nil))
  65
  66 (defsubst fuel-con--request-deactivated-p (req)
  67   (null (cdr (assoc :continuation req))))
  68
  69 (defsubst fuel-con--make-connection (buffer)
  70   (list :fuel-connection
  71         (cons :requests (list))
  72         (cons :current nil)
  73         (cons :completed (make-hash-table :weakness 'value))
  74         (cons :buffer buffer)
  75         (cons :timer nil)))
  76
  77 (defsubst fuel-con--connection-p (c)
  78   (and (listp c) (eq (car c) :fuel-connection)))
  79
  80 (defsubst fuel-con--connection-requests (c)
  81   (cdr (assoc :requests c)))
  82
  83 (defsubst fuel-con--connection-current-request (c)
  84   (cdr (assoc :current c)))
  85
  86 (defun fuel-con--connection-clean-current-request (c)
  87   (let* ((cell (assoc :current c))
  88          (req (cdr cell)))
  89     (when req
  90       (puthash (fuel-con--request-id req) req (cdr (assoc :completed c)))
  91       (setcdr cell nil))))
  92
  93 (defsubst fuel-con--connection-completed-p (c id)
  94   (gethash id (cdr (assoc :completed c))))
  95
  96 (defsubst fuel-con--connection-buffer (c)
  97   (cdr (assoc :buffer c)))
  98
  99 (defun fuel-con--connection-pop-request (c)
 100   (let ((reqs (assoc :requests c))
 101         (current (assoc :current c)))
 102     (setcdr current (prog1 (cadr reqs) (setcdr reqs (cddr reqs))))
 103     (if (and (cdr current)
 104              (fuel-con--request-deactivated-p (cdr current)))
 105         (fuel-con--connection-pop-request c)
 106       (cdr current))))
 107
 108 (defun fuel-con--connection-start-timer (c)
 109   (let ((cell (assoc :timer c)))
 110     (when (cdr cell) (cancel-timer (cdr cell)))
 111     (setcdr cell (run-at-time t 0.5 'fuel-con--process-next c))))
 112
 113 (defun fuel-con--connection-cancel-timer (c)
 114   (let ((cell (assoc :timer c)))
 115     (when (cdr cell) (cancel-timer (cdr cell)))))
 116
 117 \f
 118 ;;; Connection setup:
 119
 120 (defun fuel-con--cleanup-connection (c)
 121   (fuel-con--connection-cancel-timer c))
 122
 123 (defun fuel-con--setup-connection (buffer)
 124   (set-buffer buffer)
 125   (fuel-con--cleanup-connection fuel-con--connection)
 126   (setq fuel-con--connection nil)
 127   (let ((conn (fuel-con--make-connection buffer)))
 128     (fuel-con--setup-comint)
 129     (fuel-con--establish-connection conn buffer)))
 130
 131 (defconst fuel-con--prompt-regex "( .+ ) ")
 132 (defconst fuel-con--eot-marker "<~FUEL~>")
 133 (defconst fuel-con--init-stanza "USE: fuel fuel-retort")
 134
 135 (defconst fuel-con--comint-finished-regex-connected
 136   (format "^%s$" fuel-con--eot-marker))
 137
 138 (defvar fuel-con--comint-finished-regex fuel-con--prompt-regex)
 139
 140 (defun fuel-con--setup-comint ()
 141   (set (make-local-variable 'comint-redirect-insert-matching-regexp) t)
 142   (add-hook 'comint-redirect-filter-functions
 143             'fuel-con--comint-preoutput-filter nil t)
 144   (add-hook 'comint-redirect-hook
 145             'fuel-con--comint-redirect-hook nil t))
 146
 147 (defadvice comint-redirect-setup (after fuel-con--advice activate)
 148   (setq comint-redirect-finished-regexp fuel-con--comint-finished-regex))
 149
 150 (defun fuel-con--comint-preoutput-filter (str)
 151   (when (string-match fuel-con--comint-finished-regex str)
 152     (setq comint-redirect-finished-regexp fuel-con--prompt-regex))
 153   str)
 154
 155 (defun fuel-con--establish-connection (conn buffer)
 156   (with-current-buffer (fuel-con--comint-buffer) (erase-buffer))
 157   (with-current-buffer buffer
 158     (setq fuel-con--connection conn)
 159     (setq fuel-con--comint-finished-regex fuel-con--prompt-regex)
 160     (fuel-con--send-string/wait buffer
 161                                 fuel-con--init-stanza
 162                                 'fuel-con--establish-connection-cont
 163                                 60000)
 164     conn))
 165
 166 (defun fuel-con--establish-connection-cont (ignore)
 167   (let ((str (with-current-buffer (fuel-con--comint-buffer) (buffer-string))))
 168     (if (string-match fuel-con--eot-marker str)
 169         (progn
 170           (setq fuel-con--comint-finished-regex
 171                 fuel-con--comint-finished-regex-connected)
 172           (fuel-con--connection-start-timer conn)
 173           (message "FUEL listener up and running!"))
 174       (fuel-con--connection-clean-current-request fuel-con--connection)
 175       (setq fuel-con--connection nil)
 176       (message "An error occurred initialising FUEL's Factor library!")
 177       (pop-to-buffer (fuel-con--comint-buffer)))))
 178
 179 \f
 180 ;;; Requests handling:
 181
 182 (defsubst fuel-con--comint-buffer ()
 183   (get-buffer-create " *fuel connection retort*"))
 184
 185 (defun fuel-con--comint-buffer-form ()
 186   (with-current-buffer (fuel-con--comint-buffer)
 187     (goto-char (point-min))
 188     (condition-case nil
 189         (let ((form (read (current-buffer))))
 190           (if (listp form) form
 191             (list 'fuel-con-error (buffer-string))))
 192       (error (list 'fuel-con-error (buffer-string))))))
 193
 194 (defun fuel-con--process-next (con)
 195   (when (not (fuel-con--connection-current-request con))
 196     (let* ((buffer (fuel-con--connection-buffer con))
 197            (req (fuel-con--connection-pop-request con))
 198            (str (and req (fuel-con--request-string req)))
 199            (cbuf (with-current-buffer (fuel-con--comint-buffer)
 200                    (erase-buffer)
 201                    (current-buffer))))
 202       (if (not (buffer-live-p buffer))
 203           (fuel-con--connection-cancel-timer con)
 204         (when (and buffer req str)
 205           (set-buffer buffer)
 206           (fuel-log--info "<%s>: %s" (fuel-con--request-id req) str)
 207           (comint-redirect-send-command (format "%s" str) cbuf nil t))))))
 208
 209 (defun fuel-con--process-completed-request (req)
 210   (let ((cont (fuel-con--request-continuation req))
 211         (id (fuel-con--request-id req))
 212         (rstr (fuel-con--request-string req))
 213         (buffer (fuel-con--request-buffer req)))
 214     (if (not cont)
 215         (fuel-log--warn "<%s> Droping result for request %S (%s)"
 216                             id rstr req)
 217       (condition-case cerr
 218           (with-current-buffer (or buffer (current-buffer))
 219             (funcall cont (fuel-con--comint-buffer-form))
 220             (fuel-log--info "<%s>: processed" id))
 221         (error (fuel-log--error
 222                 "<%s>: continuation failed %S \n\t%s" id rstr cerr))))))
 223
 224 (defun fuel-con--comint-redirect-hook ()
 225   (if (not fuel-con--connection)
 226       (fuel-log--error "No connection in buffer")
 227     (let ((req (fuel-con--connection-current-request fuel-con--connection)))
 228       (if (not req) (fuel-log--error "No current request")
 229         (fuel-con--process-completed-request req)
 230         (fuel-con--connection-clean-current-request fuel-con--connection)))))
 231
 232 \f
 233 ;;; Message sending interface:
 234
 235 (defconst fuel-con--error-message "FUEL connection not active")
 236
 237 (defun fuel-con--send-string (buffer/proc str cont &optional sender-buffer)
 238   (save-current-buffer
 239     (let ((con (fuel-con--get-connection buffer/proc)))
 240       (unless con (error fuel-con--error-message))
 241       (let ((req (fuel-con--make-request str cont sender-buffer)))
 242         (fuel-con--connection-queue-request con req)
 243         (fuel-con--process-next con)
 244         req))))
 245
 246 (defvar fuel-connection-timeout 30000
 247   "Time limit, in msecs, blocking on synchronous evaluation requests")
 248
 249 (defun fuel-con--send-string/wait (buffer/proc str cont &optional timeout sbuf)
 250   (save-current-buffer
 251     (let ((con (fuel-con--get-connection buffer/proc)))
 252       (unless con (error fuel-con--error-message))
 253       (let* ((req (fuel-con--send-string buffer/proc str cont sbuf))
 254              (id (and req (fuel-con--request-id req)))
 255              (time (or timeout fuel-connection-timeout))
 256              (step 100)
 257              (waitsecs (/ step 1000.0)))
 258         (when id
 259           (condition-case nil
 260               (while (and (> time 0)
 261                           (not (fuel-con--connection-completed-p con id)))
 262                 (accept-process-output nil waitsecs)
 263                 (setq time (- time step)))
 264             (error (setq time 0)))
 265           (or (> time 0)
 266               (fuel-con--request-deactivate req)
 267               nil))))))
 268
 269 \f
 270 (provide 'fuel-connection)
 271 ;;; fuel-connection.el ends here