;;; gnus-async.el --- asynchronous support for Gnus
-;; Copyright (C) 1996 Free Software Foundation, Inc.
-;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
+;; Copyright (C) 1996-2015 Free Software Foundation, Inc.
+
+;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: news
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs 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 2, or (at your option)
-;; any later version.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
;; GNU Emacs 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
+;; 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 GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
-(require 'gnus-load)
+(eval-when-compile (require 'cl))
+
+(require 'gnus)
(require 'gnus-sum)
(require 'nntp)
-(defvar gnus-use-article-prefetch 30
+(defgroup gnus-asynchronous nil
+ "Support for asynchronous operations."
+ :group 'gnus)
+
+(defcustom gnus-use-article-prefetch 30
"*If non-nil, prefetch articles in groups that allow this.
If a number, prefetch only that many articles forward;
-if t, prefetch as many articles as possible.")
+if t, prefetch as many articles as possible."
+ :group 'gnus-asynchronous
+ :type '(choice (const :tag "off" nil)
+ (const :tag "all" t)
+ (integer :tag "some" 0)))
+
+(defcustom gnus-asynchronous nil
+ "*If nil, inhibit all Gnus asynchronicity.
+If non-nil, let the other asynch variables be heeded."
+ :group 'gnus-asynchronous
+ :type 'boolean)
-(defvar gnus-prefetched-article-deletion-strategy '(read exit)
+(defcustom gnus-prefetched-article-deletion-strategy '(read exit)
"List of symbols that say when to remove articles from the prefetch buffer.
-Possible values in this list are `read', which means that
+Possible values in this list are `read', which means that
articles are removed as they are read, and `exit', which means
that all articles belonging to a group are removed on exit
-from that group.")
+from that group."
+ :group 'gnus-asynchronous
+ :type '(set (const read) (const exit)))
-(defvar gnus-use-header-prefetch nil
- "*If non-nil, prefetch the headers to the next group.")
+(defcustom gnus-use-header-prefetch nil
+ "*If non-nil, prefetch the headers to the next group."
+ :group 'gnus-asynchronous
+ :type 'boolean)
+
+(defcustom gnus-async-prefetch-article-p 'gnus-async-unread-p
+ "Function called to say whether an article should be prefetched or not.
+The function is called with one parameter -- the article data.
+It should return non-nil if the article is to be prefetched."
+ :group 'gnus-asynchronous
+ :type 'function)
+
+(defcustom gnus-async-post-fetch-function nil
+ "Function called after an article has been prefetched.
+The function will be called narrowed to the region of the article
+that was fetched."
+ :version "24.1"
+ :group 'gnus-asynchronous
+ :type '(choice (const nil) function))
;;; Internal variables.
(defvar gnus-async-prefetch-article-buffer " *Async Prefetch Article*")
(defvar gnus-async-article-alist nil)
+(defvar gnus-async-article-semaphore '(nil))
+(defvar gnus-async-fetch-list nil)
+(defvar gnus-async-hashtb nil)
+(defvar gnus-async-current-prefetch-group nil)
+(defvar gnus-async-current-prefetch-article nil)
+(defvar gnus-async-timer nil)
(defvar gnus-async-prefetch-headers-buffer " *Async Prefetch Headers*")
-(defvar gnus-asynch-header-prefetched nil)
+(defvar gnus-async-header-prefetched nil)
;;; Utility functions.
(defun gnus-group-asynchronous-p (group)
- "Say whether GROUP is fetched from a server that supports asynchronocity."
+ "Say whether GROUP is fetched from a server that supports asynchronicity."
(gnus-asynchronous-p (gnus-find-method-for-group group)))
+;;; Somewhat bogus semaphores.
+
+(defun gnus-async-get-semaphore (semaphore)
+ "Wait until SEMAPHORE is released."
+ (while (/= (length (nconc (symbol-value semaphore) (list nil))) 2)
+ (sleep-for 1)))
+
+(defun gnus-async-release-semaphore (semaphore)
+ "Release SEMAPHORE."
+ (setcdr (symbol-value semaphore) nil))
+
+(defmacro gnus-async-with-semaphore (&rest forms)
+ `(unwind-protect
+ (progn
+ (gnus-async-get-semaphore 'gnus-async-article-semaphore)
+ ,@forms)
+ (gnus-async-release-semaphore 'gnus-async-article-semaphore)))
+
+(put 'gnus-async-with-semaphore 'lisp-indent-function 0)
+(put 'gnus-async-with-semaphore 'edebug-form-spec '(body))
+
;;;
;;; Article prefetch
;;;
(defun gnus-async-close ()
(gnus-kill-buffer gnus-async-prefetch-article-buffer)
(gnus-kill-buffer gnus-async-prefetch-headers-buffer)
- (setq gnus-async-article-alist nil
- gnus-asynch-header-prefetched nil))
+ (setq gnus-async-hashtb nil
+ gnus-async-article-alist nil
+ gnus-async-header-prefetched nil))
+
+(defun gnus-async-set-buffer ()
+ (nnheader-set-temp-buffer gnus-async-prefetch-article-buffer t)
+ (unless gnus-async-hashtb
+ (setq gnus-async-hashtb (gnus-make-hashtable 1023))))
+
+(defun gnus-async-halt-prefetch ()
+ "Stop prefetching."
+ (setq gnus-async-fetch-list nil))
(defun gnus-async-prefetch-next (group article summary)
"Possibly prefetch several articles starting with the article after ARTICLE."
- (let ((next (caadr (gnus-data-find-list article))))
- (when next
- (gnus-async-prefetch-article group next summary))))
+ (when (and (gnus-buffer-live-p summary)
+ gnus-asynchronous
+ (gnus-group-asynchronous-p group))
+ (with-current-buffer gnus-summary-buffer
+ (let ((next (caadr (gnus-data-find-list article))))
+ (when next
+ (if (not (fboundp 'run-with-idle-timer))
+ ;; This is either an older Emacs or XEmacs, so we
+ ;; do this, which leads to slightly slower article
+ ;; buffer display.
+ (gnus-async-prefetch-article group next summary)
+ (when gnus-async-timer
+ (ignore-errors
+ (nnheader-cancel-timer 'gnus-async-timer)))
+ (setq gnus-async-timer
+ (run-with-idle-timer
+ 0.1 nil 'gnus-async-prefetch-article
+ group next summary))))))))
-(defun gnus-async-prefetch-article (group article summary &optional number)
+(defun gnus-async-prefetch-article (group article summary &optional next)
"Possibly prefetch several articles starting with ARTICLE."
- (unless number
- (setq number gnus-use-article-prefetch))
- (when (and number
- (or (not (numberp number))
- (> number 0))
- (gnus-group-asynchronous-p group)
- (gnus-buffer-live-p summary))
- (when (numberp number)
- (decf number))
- (while (and article (gnus-async-prefetched-article-entry group article))
- (setq article (caadr (gnus-data-find-list article)))
- (when (numberp number)
- (decf number)))
- (when article
- ;; We want to fetch some more articles.
+ (if (not (gnus-buffer-live-p summary))
+ (gnus-async-with-semaphore
+ (setq gnus-async-fetch-list nil))
+ (when (and gnus-asynchronous
+ (gnus-alive-p))
+ (when next
+ (gnus-async-with-semaphore
+ (pop gnus-async-fetch-list)))
+ (let ((do-fetch next)
+ (do-message t)) ;(eq major-mode 'gnus-summary-mode)))
+ (when (and (gnus-group-asynchronous-p group)
+ (gnus-buffer-live-p summary)
+ (or (not next)
+ gnus-async-fetch-list))
+ (gnus-async-with-semaphore
+ (unless next
+ (setq do-fetch (not gnus-async-fetch-list))
+ ;; Nix out any outstanding requests.
+ (setq gnus-async-fetch-list nil)
+ ;; Fill in the new list.
+ (let ((n gnus-use-article-prefetch)
+ (data (gnus-data-find-list article))
+ d)
+ (while (and (setq d (pop data))
+ (if (numberp n)
+ (natnump (decf n))
+ n))
+ (unless (or (gnus-async-prefetched-article-entry
+ group (setq article (gnus-data-number d)))
+ (not (natnump article))
+ (not (funcall gnus-async-prefetch-article-p d)))
+ ;; Not already fetched -- so we add it to the list.
+ (push article gnus-async-fetch-list)))
+ (setq gnus-async-fetch-list
+ (nreverse gnus-async-fetch-list))))
+
+ (when do-fetch
+ (setq article (car gnus-async-fetch-list))))
+
+ (when (and do-fetch article)
+ ;; We want to fetch some more articles.
+ (with-current-buffer summary
+ (let (mark)
+ (gnus-async-set-buffer)
+ (goto-char (point-max))
+ (setq mark (point-marker))
+ (let ((nnheader-callback-function
+ (gnus-make-async-article-function
+ group article mark summary next))
+ (nntp-server-buffer
+ (get-buffer gnus-async-prefetch-article-buffer)))
+ (when do-message
+ (gnus-message 9 "Prefetching article %d in group %s"
+ article group))
+ (setq gnus-async-current-prefetch-group group)
+ (setq gnus-async-current-prefetch-article article)
+ (gnus-request-article article group))))))))))
+
+(defun gnus-make-async-article-function (group article mark summary next)
+ "Return a callback function."
+ `(lambda (arg)
+ (gnus-async-article-callback arg ,group ,article ,mark ,summary ,next)))
+
+(defun gnus-async-article-callback (arg group article mark summary next)
+ "Function called when an async article is done being fetched."
+ (save-excursion
+ (setq gnus-async-current-prefetch-article nil)
+ (when arg
+ (gnus-async-set-buffer)
(save-excursion
- (set-buffer summary)
- (let ((next (caadr (gnus-data-find-list article)))
- mark)
- (nnheader-set-temp-buffer gnus-async-prefetch-article-buffer t)
- (goto-char (point-max))
- (setq mark (point-marker))
- (let ((nnheader-callback-function
- `(lambda (arg)
- (save-excursion
- (nnheader-set-temp-buffer
- gnus-async-prefetch-article-buffer t)
- (push (list ',(intern (format "%s-%d" group article))
- ,mark (set-marker (make-marker) (point-max))
- ,group ,article)
- gnus-async-article-alist)
- (when (gnus-buffer-live-p ,summary)
- ,(when next
- `(gnus-async-prefetch-article
- ,group ,next ,summary ,number))))))
- (nntp-server-buffer (get-buffer
- gnus-async-prefetch-article-buffer)))
- (gnus-message 7 "Prefetching article %d in group %s"
- article group)
- (gnus-request-article article group)))))))
+ (save-restriction
+ (narrow-to-region mark (point-max))
+ ;; Put the articles into the agent, if they aren't already.
+ (when (and gnus-agent
+ (gnus-agent-group-covered-p group))
+ (save-restriction
+ (narrow-to-region mark (point-max))
+ (gnus-agent-store-article article group)))
+ ;; Prefetch images for the groups that want that.
+ (when (fboundp 'gnus-html-prefetch-images)
+ (gnus-html-prefetch-images summary))
+ (when gnus-async-post-fetch-function
+ (funcall gnus-async-post-fetch-function summary))))
+ (gnus-async-with-semaphore
+ (setq
+ gnus-async-article-alist
+ (cons (list (intern (format "%s-%d" group article)
+ gnus-async-hashtb)
+ mark (point-max-marker)
+ group article)
+ gnus-async-article-alist))))
+ (if (not (gnus-buffer-live-p summary))
+ (gnus-async-with-semaphore
+ (setq gnus-async-fetch-list nil))
+ (gnus-async-prefetch-article group next summary t))))
+
+(defun gnus-async-unread-p (data)
+ "Return non-nil if DATA represents an unread article."
+ (gnus-data-unread-p data))
(defun gnus-async-request-fetched-article (group article buffer)
"See whether we have ARTICLE from GROUP and put it in BUFFER."
(when (numberp article)
+ (when (and (equal group gnus-async-current-prefetch-group)
+ (eq article gnus-async-current-prefetch-article))
+ (gnus-async-wait-for-article article))
(let ((entry (gnus-async-prefetched-article-entry group article)))
(when entry
(save-excursion
- (nnheader-set-temp-buffer gnus-async-prefetch-article-buffer t)
+ (gnus-async-set-buffer)
(copy-to-buffer buffer (cadr entry) (caddr entry))
;; Remove the read article from the prefetch buffer.
(when (memq 'read gnus-prefetched-article-deletion-strategy)
- (gnus-asynch-delete-prefected-entry entry))
- ;; Decode the article. Perhaps this shouldn't be done
- ;; here?
- (set-buffer buffer)
- (nntp-decode-text)
- (goto-char (point-min))
- (gnus-delete-line)
+ (gnus-async-delete-prefetched-entry entry))
t)))))
-(defun gnus-asynch-delete-prefected-entry (entry)
+(defun gnus-async-wait-for-article (article)
+ "Wait until ARTICLE is no longer the currently-being-fetched article."
+ (save-excursion
+ (gnus-async-set-buffer)
+ (let ((proc (nntp-find-connection (current-buffer)))
+ (nntp-server-buffer (current-buffer))
+ (nntp-have-messaged nil)
+ (tries 0))
+ (when proc
+ (condition-case nil
+ ;; FIXME: we could stop waiting after some
+ ;; timeout, but this is the wrong place to do it.
+ ;; rather than checking time-spent-waiting, we
+ ;; should check time-since-last-output, which
+ ;; needs to be done in nntp.el.
+ (while (eq article gnus-async-current-prefetch-article)
+ (incf tries)
+ (when (nntp-accept-process-output proc)
+ (setq tries 0))
+ (when (and (not nntp-have-messaged)
+ (= tries 3))
+ (gnus-message 5 "Waiting for async article...")
+ (setq nntp-have-messaged t)))
+ (quit
+ ;; if the user interrupted on a slow/hung connection,
+ ;; do something friendly.
+ (when (> tries 3)
+ (setq gnus-async-current-prefetch-article nil))
+ (signal 'quit nil)))
+ (when nntp-have-messaged
+ (gnus-message 5 ""))))))
+
+(defun gnus-async-delete-prefetched-entry (entry)
"Delete ENTRY from buffer and alist."
- (delete-region (cadr entry) (caddr entry))
- (set-marker (cadr entry) nil)
- (set-marker (caddr entry) nil)
- (setq gnus-async-article-alist
- (delq entry gnus-async-article-alist)))
+ (ignore-errors
+ (delete-region (cadr entry) (caddr entry))
+ (set-marker (cadr entry) nil)
+ (set-marker (caddr entry) nil))
+ (gnus-async-with-semaphore
+ (setq gnus-async-article-alist
+ (delq entry gnus-async-article-alist))
+ (unintern (car entry) gnus-async-hashtb)))
(defun gnus-async-prefetch-remove-group (group)
"Remove all articles belonging to GROUP from the prefetch buffer."
(when (and (gnus-group-asynchronous-p group)
(memq 'exit gnus-prefetched-article-deletion-strategy))
- (let ((alist gnus-async-article-alist))
- (save-excursion
- (nnheader-set-temp-buffer gnus-async-prefetch-article-buffer t)
- (while alist
- (when (equal group (nth 3 (car alist)))
- (gnus-asynch-delete-prefected-entry (car alist)))
- (pop alist))))))
-
+ (save-excursion
+ (gnus-async-set-buffer)
+ (dolist (entry gnus-async-article-alist)
+ (when (equal group (nth 3 entry))
+ (gnus-async-delete-prefetched-entry entry))))))
+
(defun gnus-async-prefetched-article-entry (group article)
- "Return the entry for ARTICLE in GROUP iff it has been prefetched."
- (assq (intern (format "%s-%d" group article))
- gnus-async-article-alist))
+ "Return the entry for ARTICLE in GROUP if it has been prefetched."
+ (let ((entry (save-excursion
+ (gnus-async-set-buffer)
+ (assq (intern-soft (format "%s-%d" group article)
+ gnus-async-hashtb)
+ gnus-async-article-alist))))
+ ;; Perhaps something has emptied the buffer?
+ (if (and entry
+ (= (cadr entry) (caddr entry)))
+ (progn
+ (ignore-errors
+ (set-marker (cadr entry) nil)
+ (set-marker (caddr entry) nil))
+ (setq gnus-async-article-alist
+ (delq entry gnus-async-article-alist))
+ nil)
+ entry)))
;;;
;;; Header prefetch
(save-excursion
(let (unread)
(when (and gnus-use-header-prefetch
+ gnus-asynchronous
(gnus-group-asynchronous-p group)
- (listp gnus-asynch-header-prefetched)
+ (listp gnus-async-header-prefetched)
(setq unread (gnus-list-of-unread-articles group)))
;; Mark that a fetch is in progress.
- (setq gnus-asynch-header-prefetched t)
+ (setq gnus-async-header-prefetched t)
(nnheader-set-temp-buffer gnus-async-prefetch-headers-buffer t)
(erase-buffer)
(let ((nntp-server-buffer (current-buffer))
(nnheader-callback-function
`(lambda (arg)
- (setq gnus-asynch-header-prefetched
+ (setq gnus-async-header-prefetched
,(cons group unread)))))
(gnus-retrieve-headers unread group gnus-fetch-old-headers))))))
-(defun gnus-asynch-retrieve-fetched-headers (articles group)
+(defun gnus-async-retrieve-fetched-headers (articles group)
"See whether we have prefetched headers."
(when (and gnus-use-header-prefetch
(gnus-group-asynchronous-p group)
- (listp gnus-asynch-header-prefetched)
- (equal group (car gnus-asynch-header-prefetched))
- (equal articles (cdr gnus-asynch-header-prefetched)))
+ (listp gnus-async-header-prefetched)
+ (equal group (car gnus-async-header-prefetched))
+ (equal articles (cdr gnus-async-header-prefetched)))
(save-excursion
(nnheader-set-temp-buffer gnus-async-prefetch-headers-buffer t)
(nntp-decode-text)
(copy-to-buffer nntp-server-buffer (point-min) (point-max))
(erase-buffer)
- (setq gnus-asynch-header-prefetched nil)
+ (setq gnus-async-header-prefetched nil)
t)))
-
+
(provide 'gnus-async)
;;; gnus-async.el ends here
projects / gnus / blobdiff