Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
Fetching contributors…

Octocat-spinner-32-eaf2f5

Cannot retrieve contributors at this time

file 849 lines (736 sloc) 26.669 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
;;; rudel-obby-server.el --- Server component of the Rudel obby backend
;;
;; Copyright (C) 2008, 2009, 2010 Jan Moringen
;;
;; Author: Jan Moringen <scymtym@users.sourceforge.net>
;; Keywords: Rudel, obby, backend, server
;; X-RCS: $Id:$
;;
;; This file is part of Rudel.
;;
;; Rudel is free software: you can redistribute it and/or modify it
;; under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;;
;; Rudel is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with Rudel. If not, see <http://www.gnu.org/licenses>.


;;; Commentary:
;;
;; This file contains the server part of the obby backend for Rudel.
;;
;; It is implemented using one state machine (class
;; `rudel-obby-client') for each client connection. These state
;; machines have the following states:
;;
;; + new `rudel-obby-server-state-new'
;; + encryption-negotiate `rudel-obby-server-state-encryption-negotiate'
;; + before-join `rudel-obby-server-state-before-join'
;; + idle `rudel-obby-server-state-idle'


;;; History:
;;
;; 0.3 - Support for transports
;;
;; 0.2 - State machine
;;
;; 0.1 - Initial version


;;; Code:
;;

(eval-when-compile
  (require 'cl))

(require 'warnings)

(require 'eieio)

(require 'jupiter)

(require 'rudel-state-machine)

(require 'rudel-obby) ;; to silence the byte-compiler
(require 'rudel-obby-errors)
(require 'rudel-obby-util)
(require 'rudel-obby-state)
(require 'rudel-obby) ;; for `rudel-obby-user' and `rudel-obby-document'


;;; Class rudel-obby-server-state-new
;;

(defclass rudel-obby-server-state-new
  (rudel-obby-server-connection-state)
  ()
  "State in which new connections start out."
  :method-invocation-order :c3)

(defmethod rudel-enter ((this rudel-obby-server-state-new))
  "Sends welcome messages to the client and starts the session
timeout timer."
  ;; Send greeting sequence to the client.
  (rudel-send this
"obby_welcome"
(number-to-string rudel-obby-protocol-version))

  ;; Switch to encryption negotiation state.
  'encryption-negotiate)


;;; Class rudel-obby-server-state-encryption-negotiate
;;

(defclass rudel-obby-server-state-encryption-negotiate
  (rudel-obby-server-connection-state)
  ()
  "Encryption negotiation state."
  :method-invocation-order :c3)

(defmethod rudel-enter ((this rudel-obby-server-state-encryption-negotiate))
  "Send net6 'encryption' message requesting to not enable encryption."
  (rudel-send this "net6_encryption" "0")
  nil)

(defmethod rudel-obby/net6_encryption_ok
  ((this rudel-obby-server-state-encryption-negotiate))
  "Handle net6 'encryption_ok' message.
Even if the client requests an encrypted connection, we cancel
the negotiation."
  (rudel-send this "net6_encryption_failed")
  'before-join)

(defmethod rudel-obby/net6_encryption_failed
  ((this rudel-obby-server-state-encryption-negotiate))
  "Handle net6 'encryption_failed' message.
No action has to be taken, since the client simply proceeds after
failed encryption negotiation."
  'before-join)


;;; Class rudel-obby-server-state-before-join
;;

(defclass rudel-obby-server-state-before-join
  (rudel-obby-server-connection-state)
  ()
  "Waiting for client request joining the session."
  :method-invocation-order :c3)

(defmethod rudel-obby/net6_client_login
  ((this rudel-obby-server-state-before-join) username color
   &optional global-password user-password)
  "Handle net6 'client_login' message."
  (with-parsed-arguments ((color color))
    (with-slots (server
(client-id :id)
user
encryption) (oref this :connection)
      ;; Make sure USERNAME and COLOR are valid.
      (let ((error (rudel-check-username-and-color
server username color)))
(if error
;; If USERNAME or COLOR are invalid, send the error code
;; to the client and stay in the current state.
(progn
(rudel-send this
"net6_login_failed"
(format "%x" error))
nil)

;; Create a user object for this client and add it to the
;; server.
(setq user (rudel-make-user
server
username client-id color encryption))
(rudel-add-user server user)

;; Broadcast the join event to all clients (including the
;; new one).
(with-slots ((name :object-name) color (user-id :user-id)) user
(rudel-broadcast this (list 'exclude (oref this :connection))
"net6_client_join"
(format "%x" client-id)
name
"0"
(format "%x" user-id)
(rudel-obby-format-color color)))

;; Get the new client up to date:
;; - transmit user list
;; - connected users
;; - disconnected users
;; - transmit document list
(with-slots (users clients documents) server
;; Send number of synchronization items: sum of numbers of
;; offline users and documents.
(let ((number-of-items (+ (length users) (length documents))))
(rudel-send this
"obby_sync_init"
(format "%x" number-of-items)))

;; Transmit list of connected users.
(dolist (client clients)
(with-slots ((client-id :id) user) client
(when user
(with-slots ((name :object-name)
color
(user-id :user-id)) user
(rudel-send this
"net6_client_join"
(format "%x" client-id)
name
"0"
(format "%x" user-id)
(rudel-obby-format-color color))))))

;; Transmit list of disconnected users.
(let ((offline-users (remove-if #'rudel-connected users)))
(dolist (user offline-users)
(with-slots ((name :object-name) user-id color) user
(rudel-send this
"obby_sync_usertable_user"
(format "%x" user-id)
name
(rudel-obby-format-color color)))))

;; Transmit document list
(dolist (document documents)
(with-slots ((name :object-name)
(doc-id :id)
owner-id
suffix
subscribed) document
(apply #'rudel-send
this
"obby_sync_doclist_document"
(format "%x" owner-id)
(format "%x" doc-id)
name
(format "%x" suffix)
"UTF-8"
(mapcar
(lambda (user1) ;; TODO we could use `user' here, but there is a bug in cl
(format "%x" (rudel-id user1)))
subscribed)))))

(rudel-send this "obby_sync_final")
'idle))))
  )


;;; Class rudel-obby-server-state-idle
;;

(defclass rudel-obby-server-state-idle
  (rudel-obby-server-connection-state
   rudel-obby-document-handler)
  ((document-container-slot :initform 'server))
  "Idle state of a server connection.

The connection enters this state when all setup work is finished,
the client has joined the session and no operation is in
progress. In this state, the connection waits for new messages
from the client that initiate operations. Simple (which means
stateless in this case) operations are performed without leaving
the idle state."
  :method-invocation-order :c3)

(defmethod rudel-obby/obby_user_colour
  ((this rudel-obby-server-state-idle) color-)
  "Handle obby 'user_colour' message.
This method is called when the connected user requests a change
of her color to COLOR."
  (with-parsed-arguments ((color- color))
    (with-slots (user) (oref this :connection)
      (with-slots (color (user-id :user-id)) user

;; Set color slot value and notify the user object.
(setq color color-)
(rudel-change-notify user)

;; Broadcast to other clients.
(rudel-broadcast this (list 'exclude (oref this :connection))
"obby_user_colour"
(format "%x" user-id)
(rudel-obby-format-color color)))))
  nil)

(defmethod rudel-obby/obby_document_create
  ((this rudel-obby-server-state-idle)
   doc-id name encoding content)
  "Handle obby 'document_create' message."
  (with-parsed-arguments ((doc-id number)
(encoding coding-system))
    (with-slots (user server) (oref this :connection)
      (with-slots ((user-id :user-id)) user
;; Create a (hidden) buffer for the new document.
(let* ((buffer (get-buffer-create
(generate-new-buffer-name
(concat " *" name "*"))))
;; Create the new document object
(document (rudel-obby-document
name
:buffer buffer
:subscribed (list user)
:id doc-id
:owner-id user-id
:suffix 1)))

;; Initialize the buffer's content
(with-current-buffer buffer
(insert content))

(with-slots (suffix) document
;; Determine an appropriate suffix to provide an unique
;; name for the new document.
(while (rudel-find-document server
(if (= suffix 1)
name
(format "%s<%d>" name suffix))
#'string= #'rudel-unique-name)
(incf suffix))

;; Add the document to the server's document list
(rudel-add-document server document)

;; Maybe notify the creating client of the changed suffix.
(unless (= suffix 1)
(rudel-send this
"obby_document"
(format "%x %x" user-id doc-id)
"rename"
(format "%x" user-id)
name
(format "%x" suffix)))

;; Notify other clients of the new document
(rudel-broadcast this (list 'exclude (oref this :connection))
"obby_document_create"
(format "%x" user-id)
(format "%x" doc-id)
name
(format "%x" suffix)
(upcase (symbol-name encoding))))

;; Add a jupiter context for (THIS DOCUMENT).
(rudel-add-context server (oref this :connection) document))))
    nil)
  )

(defmethod rudel-obby/obby_document/subscribe
  ((this rudel-obby-server-state-idle) document user-id)
  "Handle 'subscribe' submessage of obby 'document' message."
  (with-parsed-arguments ((user-id number))
    (let ((user (with-slots (server) (oref this :connection)
(rudel-find-user server user-id
#'= #'rudel-id))))
      (with-slots (owner-id (doc-id :id) subscribed buffer) document

;; Track subscription, handle duplicate subscription requests.
(when (memq user subscribed)
(error "User `%s' already subscribed to document `%s'"
(object-name user) (object-name document)))
(rudel-add-user document user)

;; Synchronize the buffer content to the client.
(with-current-buffer buffer
;; Send overall buffer size
(rudel-send this
"obby_document"
(format "%x %x" owner-id doc-id)
"sync_init"
(format "%x" (1- (position-bytes (point-max)))))

;; Send buffer chunks with author ids
(dolist (chunk (rudel-chunks document))
(multiple-value-bind (from to author) chunk
(let ((string (buffer-substring (+ from 1) (+ to 1))))
(rudel-send this
"obby_document"
(format "%x %x" owner-id doc-id)
"sync_chunk"
string
(format "%x"
(if author
(oref author :user-id)
0)))))))

;; Notify clients of the new subscription (including our own
;; client, who requested the subscription).
(with-slots ((user-id :user-id)) user
(rudel-broadcast this nil
"obby_document"
(format "%x %x" owner-id doc-id)
"subscribe"
(format "%x" user-id)))))

    ;; Add a jupiter context for (THIS document).
    (with-slots (server) (oref this :connection)
      (rudel-add-context server (oref this :connection) document))
    nil)
  )

(defmethod rudel-obby/obby_document/unsubscribe
  ((this rudel-obby-server-state-idle) document user-id)
  "Handle 'unsubscribe' submessage of 'obby_document' message."
  (with-parsed-arguments ((user-id number))
    (let ((user (with-slots (server) (oref this :connection)
(rudel-find-user server user-id
#'= #'rudel-id))))
      (with-slots (owner-id (doc-id :id) subscribed) document

;; Track subscription, handle invalid unsubscribe requests
(unless (memq user subscribed)
(error "User `%s' not subscribed to document `%s'"
(object-name user) (object-name document)))
(rudel-remove-user document user)

;; Notify clients of the canceled subscription (including our
;; own client, who requested being unsubscribed).
(with-slots ((user-id :user-id)) user
(rudel-broadcast this nil
"obby_document"
(format "%x %x" owner-id doc-id)
"unsubscribe"
(format "%x" user-id))))

      ;; Remove jupiter context for (THIS DOCUMENT).
      (with-slots (server) (oref this :connection)
(rudel-remove-context server (oref this :connection) document)))
    nil)
  )

(defmethod rudel-obby/obby_document/record
  ((this rudel-obby-server-state-idle)
   document local-revision remote-revision action &rest arguments)
  "Handle 'record' submessages of 'obby_document' message."
  (with-parsed-arguments ((local-revision number)
(remote-revision number))
    ;; Dispatch to specialized operation handlers.
    (rudel-dispatch
     this "rudel-obby/obby_document/record/" action
     (append (list document local-revision remote-revision)
arguments)))
  )

(defmethod rudel-obby/obby_document/record/ins
  ((this rudel-obby-server-state-idle)
   document local-revision remote-revision position data)
  "Handle 'ins' submessage of 'record' submessages of 'obby_document' message."
  (with-parsed-arguments ((position number))
    ;; Construct the operation object and process it.
    (rudel-remote-operation
     (oref this :connection) document
     remote-revision local-revision
     (jupiter-insert
      (format "insert-%d-%d"
remote-revision local-revision)
      :from position
      :data data))
    nil)
  )

(defmethod rudel-obby/obby_document/record/del
  ((this rudel-obby-server-state-idle)
   document local-revision remote-revision position length)
  "Handle 'del' submessage of 'record' submessages of 'obby_document' message."
  (with-parsed-arguments ((position number)
(length number))
    ;; Construct the operation object and process it.
    (rudel-remote-operation
     (oref this :connection) document
     remote-revision local-revision
     (jupiter-delete
      (format "delete-%d-%d"
remote-revision local-revision)
      :from position
      :to (+ position length)))
    nil)
  )


;;; Client connection states.
;;

(defvar rudel-obby-server-connection-states
  '((new . rudel-obby-server-state-new)
    (encryption-negotiate . rudel-obby-server-state-encryption-negotiate)
    (before-join . rudel-obby-server-state-before-join)
    (idle . rudel-obby-server-state-idle))
  "Name symbols and classes of connection states.")


;;; Class rudel-obby-client
;;

(defclass rudel-obby-client (rudel-state-machine)
  ((transport :initarg :transport
:type rudel-transport
:documentation
"The transport object through which this
connection sends and receives its data.")
   (server :initarg :server
:type rudel-obby-server
:documentation
"")
   (id :initarg :id
:type integer
:accessor rudel-id
:documentation
"")
   (user :initarg :user
:type (or rudel-obby-user null)
:initform nil
:documentation
"")
   (encryption :initarg :encryption
:type boolean
:documentation
""))
  "Each object of this class represents one client, that is
connected to the server. This object handles all direct
communication with the client, while broadcast messages are
handled by the server.")

(defmethod initialize-instance ((this rudel-obby-client) slots)
  "Initialize slots of THIS, register states and install filter."
  ;; Initialize slots of THIS
  (when (next-method-p)
    (call-next-method))

  ;; Register states.
  (rudel-register-states this rudel-obby-server-connection-states)

  ;; Set up the transport.
  (with-slots (transport) this

    ;; Build the following transport filter stack:
    ;; + `rudel-parsing-transport-filter'
    ;; + `rudel-assembling-transport-filter'
    ;; + TRANSPORT
    (setq transport (rudel-obby-make-transport-filter-stack transport))

    ;; Install process filter and sentinel.
    (lexical-let ((this1 this))
      ;; Install `rudel-accept' as filter to dispatch messages to the
      ;; current state machine state.
      (rudel-set-filter transport
(lambda (data)
(rudel-accept this1 data)))

      ;; Install a sentinel that calls `rudel-close' on THIS upon
      ;; receiving a 'close' event.
      (rudel-set-sentinel transport
(lambda (event)
(case event
(close
(rudel-close this1)))))))
  )

(defmethod rudel-register-state ((this rudel-obby-client) symbol state)
  "Register SYMBOL and STATE and set connection slot of STATE."
  ;; Associate THIS connection to STATE.
  (oset state :connection this)

  ;; Register STATE.
  (call-next-method))

(defmethod rudel-end ((this rudel-obby-client))
  ""
  (rudel-disconnect this))

(defmethod rudel-close ((this rudel-obby-client))
  ""
  (with-slots (server) this
    (rudel-remove-client server this)))

(defmethod rudel-send ((this rudel-obby-client) &rest args)
  "Send ARGS through the transport of THIS."
  (with-slots (transport) this
    (rudel-send transport args)))

(defmethod rudel-broadcast ((this rudel-obby-client)
receivers name &rest args)
  "Broadcast message NAME with arguments ARGS to RECEIVERS."
  (with-slots (server) this
    (apply #'rudel-broadcast server receivers name args)))

(defmethod rudel-remote-operation ((this rudel-obby-client)
document
local-revision remote-revision
operation)
  "Execute and relay OPERATION on DOCUMENT."
  (with-slots (server user) this
    ;; Transform OPERATION and find clients that need to receive
    ;; notifications.
    (let* ((context (rudel-find-context server this document))
(transformed (jupiter-remote-operation
context
local-revision remote-revision
operation))
(receivers (rudel-subscribed-clients-not-self
this document)))

      ;; Relay change notification to other clients. We use
      ;; TRANSFORMED before the byte -> char conversion which is what
      ;; the receivers expect.
      (with-slots (user-id) user
(with-slots (owner-id (doc-id :id)) document
;; Construct and send messages to all receivers individually
;; since the contents of the messages depends on the state
;; of the jupiter context associated the respective
;; receiver.
(dolist (receiver receivers)

;; Find the jupiter context for RECEIVER and use its
;; revision information.
(let ((context (rudel-find-context server receiver document)))
;; Construct and send one message.
(with-slots (local-revision remote-revision) context
(apply #'rudel-send
receiver
"obby_document"
(format "%x %x" owner-id doc-id)
"record"
(format "%x" user-id)
(format "%x" local-revision)
(format "%x" remote-revision)
(rudel-operation->message transformed)))

;; Submit the operation to the jupiter context.
(jupiter-local-operation context transformed)))))

      ;; Incorporate change into DOCUMENT (the server-side
      ;; document). We have to convert bytes -> chars before we can do
      ;; this.
      (with-slots (buffer) document
(rudel-obby-byte->char transformed buffer))

      (rudel-remote-operation document user transformed)))
  )

(defmethod rudel-subscribed-clients-not-self ((this rudel-obby-client)
document)
  "Return a list of clients subscribed to DOCUMENT excluding THIS."
  (with-slots (clients) (oref this :server)
    (with-slots (subscribed) document
      (remove-if
       (lambda (client)
(with-slots (user) client
(or (eq client this)
(not (memq user subscribed)))))
       clients)))
  )


;;; Class rudel-obby-server
;;

(defclass rudel-obby-server (rudel-server-session)
  ((listener :initarg :listener
:type rudel-listener
:documentation
"The listener object that dispatches incoming
connections to this server.")
   (clients :initarg :clients
:type list
:initform nil
:documentation
"List of objects representing clients
connected to the server.")
   (next-client-id :initarg :next-client-id
:type (integer 1)
:initform 1
:documentation
"An id that will be assigned to the next
client that connects to the server.")
   (next-user-id :initarg :next-user-id
:type (integer 1)
:initform 1
:documentation
"An id that will be assigned to the next user
that joins the associated session.")
   (contexts :initarg :contexts
:type hash-table
:documentation
"A hash table associating documents to jupiter
transformation context objects."))
  "Class rudel-obby-server ")

(defmethod initialize-instance ((this rudel-obby-server) slots)
  "Initialize slots of THIS and install a dispatch function."
  ;; Initialize slots of THIS.
  (when (next-method-p)
    (call-next-method))

  ;; Create a hash-table to store the contexts.
  (with-slots (contexts) this
    (setq contexts (make-hash-table :test 'equal)))

  ;; Dispatch incoming connections to our `rudel-add-client' method.
  (with-slots (listener) this
    (lexical-let ((this1 this))
      (rudel-set-dispatcher
       listener
       (lambda (client-transport)
(rudel-add-client this1 client-transport)))))
  )

(defmethod rudel-end ((this rudel-obby-server))
  ""
  (rudel-disconnect this))

(defmethod rudel-broadcast ((this rudel-obby-server)
receivers name &rest arguments)
  "Send a message of type NAME with arguments ARGUMENTS to RECEIVERS.

RECEIVERS can be a object derived from rudel-obby-client, a list
of such objects or a list with car 'exclude and cdr a list of
such objects derived from rudel-obby-client."
  ;; Construct list of receivers.
  (let ((receiver-list
(cond
;; If RECEIVERS is nil, the message should be broadcast to
;; all clients.
((null receivers) (oref this :clients))
;; If RECEIVERS is a (non-empty) list of rudel-obby-client
;; (or derived) objects, treat it as a list of receivers.
((and (listp receivers)
(rudel-obby-client-child-p (car receivers)))
receivers)
;; If RECEIVERS is a (non-empty) list with cdr equal to
;; 'exclude treat it as a list of receivers to exclude.
((and (listp receivers)
(eq (car receivers) 'exclude))
(with-slots (clients) this
(set-difference clients (cdr receivers)
:key #'rudel-id)))
;; If RECEIVERS is a single rudel-obby-client (or derived)
;; object, send the message to that client.
((rudel-obby-client-child-p receivers)
(list receivers))
;;
(t (signal 'wrong-type-argument (type-of receivers))))))

    ;; Send message to receivers.
    (dolist (receiver receiver-list)
      (apply #'rudel-send receiver name arguments)))
  )

(defmethod rudel-make-user ((this rudel-obby-server)
name client-id color encryption)
  ""
  (with-slots (next-user-id) this
    (let ((user (rudel-obby-user name
                 :color color
:client-id client-id
:user-id next-user-id
:connected t
:encryption encryption)))
      (incf next-user-id)
      user))
  )

(defmethod rudel-check-username-and-color ((this rudel-obby-server)
username color)
  "Check whether USERNAME and COLOR are valid.
USERNAME must not be empty and must not be used by another
user. COLOR has to be sufficiently different from used colors."
  (cond
   ;; The empty user name is not allowed
   ((string= username "")
    rudel-obby-error-username-invalid)

   ;; Make sure the user name is not already in use.
   ((rudel-find-user this username
#'string= #'object-name-string)
    rudel-obby-error-username-in-use)

   ;; Make sure COLOR is a valid color.
   ((not (color-values color))
    rudel-obby-error-color-invalid)

   ;; Make sure the color is sufficiently dissimilar to all used
   ;; colors.
   ((rudel-find-user this color
(lambda (left right)
(< (color-distance left right) 20000)) ;; TODO constant
#'rudel-color)
    rudel-obby-error-color-in-use))
  )

(defmethod rudel-add-client ((this rudel-obby-server)
client-transport)
  ""
  (with-slots (next-client-id clients) this
    (let ((client (rudel-obby-client
(object-name client-transport)
:server this
:transport client-transport
:id next-client-id
:encryption nil)))
      (push client clients))
    (incf next-client-id))
  )

(defmethod rudel-remove-client ((this rudel-obby-server)
client)
  ""
  (with-slots ((client-id :id) user) client
    ;; Broadcast the part event to all remaining clients.
    (rudel-broadcast this (list 'exclude client)
"net6_client_part"
(format "%x" client-id))

    ;; If the client has an associated user object, set the status of
    ;; the user object to offline.
    (when user
      ;; Set slot value.
      (with-slots (connected) user
(setq connected nil))

      ;; Run change hook.
      (object-run-hook-with-args user 'change-hook)))

  (object-remove-from-list this :clients client)
  )

(defmethod rudel-find-context ((this rudel-obby-server) client document)
  "Return the jupiter context associated to (CLIENT DOCUMENT) in THIS."
  (with-slots (contexts) this
    (gethash (rudel-obby-context-key client document) contexts)))

(defmethod rudel-add-context ((this rudel-obby-server) client document)
  "Add a jupiter context for (CLIENT DOCUMENT) to THIS."
  (with-slots (contexts) this
    (with-slots ((client-id :id)) client
      (with-slots ((doc-name :object-name)) document
(puthash
(rudel-obby-context-key client document)
(jupiter-context (format "%d-%s" client-id doc-name))
contexts))))
  )

(defmethod rudel-remove-context ((this rudel-obby-server) client document)
  "Remove the jupiter context associated to (CLIENT DOCUMENT) from THIS."
  (with-slots (contexts) this
    (remhash
     (rudel-obby-context-key client document)
     contexts)))

(defun rudel-obby-context-key (client document)
  "Generate hash key based on CLIENT and DOCUMENT."
  (with-slots ((client-id :id)) client
    (with-slots ((doc-id :id)) document
      (list client-id doc-id))))

(defmethod object-print ((this rudel-obby-server) &rest strings)
  "Print THIS with number of clients."
  (with-slots (clients) this
    (apply #'call-next-method
this
(format " clients: %d"
(length clients))
strings))
  )

(provide 'rudel-obby-server)
;;; rudel-obby-server.el ends here
Something went wrong with that request. Please try again.