xemacs-beta: lisp/gnus/nnvirtual.el comparison

comparison lisp/gnus/nnvirtual.el @ 16:0293115a14e9 r19-15b91

Import from CVS: tag r19-15b91

author	cvs
date	Mon, 13 Aug 2007 08:49:20 +0200
parents	376386a54a3c
children	d95e72db5c07

comparison

equal deleted inserted replaced

-:ad457d5f7d04
+:0293115a14e9
 ;;; nnvirtual.el --- virtual newsgroups access for Gnus
-;; Copyright (C) 1994,95,96 Free Software Foundation, Inc.
+;; Copyright (C) 1994,95,96,97 Free Software Foundation, Inc.
-;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
+;; Author: David Moore <dmoore@ucsd.edu>
+;;	Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
 ;; 	Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
 ;; Keywords: news
 ;; This file is part of GNU Emacs.
 ;; Boston, MA 02111-1307, USA.
 ;;; Commentary:
 ;; The other access methods (nntp, nnspool, etc) are general news
-;; access methods. This module relies on Gnus and can not be used
+;; access methods.  This module relies on Gnus and can not be used
 ;; separately.
 ;;; Code:
 (require 'nntp)
 (require 'nnheader)
 (require 'gnus)
 (require 'nnoo)
+(require 'gnus-util)
+(require 'gnus-start)
+(require 'gnus-sum)
 (eval-when-compile (require 'cl))
 (nnoo-declare nnvirtual)
 (defvoo nnvirtual-always-rescan nil
 virtual group.")
 (defvoo nnvirtual-component-regexp nil
 "*Regexp to match component groups.")
+(defvoo nnvirtual-component-groups nil
+"Component group in this nnvirtual group.")
-(defconst nnvirtual-version "nnvirtual 1.0")
+(defconst nnvirtual-version "nnvirtual 1.1")
 (defvoo nnvirtual-current-group nil)
-(defvoo nnvirtual-component-groups nil)
-(defvoo nnvirtual-mapping nil)
+(defvoo nnvirtual-mapping-table nil
+"Table of rules on how to map between component group and article number
+to virtual article number.")
+(defvoo nnvirtual-mapping-offsets nil
+"Table indexed by component group to an offset to be applied to article numbers in that group.")
+(defvoo nnvirtual-mapping-len 0
+"Number of articles in this virtual group.")
+(defvoo nnvirtual-mapping-reads nil
+"Compressed sequence of read articles on the virtual group as computed from the unread status of individual component groups.")
+(defvoo nnvirtual-mapping-marks nil
+"Compressed marks alist for the virtual group as computed from the marks of individual component groups.")
+(defvoo nnvirtual-info-installed nil
+"T if we have already installed the group info for this group, and shouldn't blast over it again.")
 (defvoo nnvirtual-status-string "")
 (eval-and-compile
 (autoload 'gnus-cache-articles-in-group "gnus-cache"))
 ;;; Interface functions.
 (nnoo-define-basics nnvirtual)
 (deffoo nnvirtual-retrieve-headers (articles &optional newsgroup
 					     server fetch-old)
 (when (nnvirtual-possibly-change-server server)
 (save-excursion
 (erase-buffer)
 (if (stringp (car articles))
 	  'headers
 	(let ((vbuf (nnheader-set-temp-buffer
 		     (get-buffer-create " *virtual headers*")))
-	      (unfetched (mapcar (lambda (g) (list g))
+	      (carticles (nnvirtual-partition-sequence articles))
-				 nnvirtual-component-groups))
 	      (system-name (system-name))
-	      cgroup article result prefix)
+	      cgroup carticle article result prefix)
-	  (while articles
+	  (while carticles
-	    (setq article (assq (pop articles) nnvirtual-mapping))
+	    (setq cgroup (caar carticles))
-	    (when (and (setq cgroup (cadr article))
+	    (setq articles (cdar carticles))
+	    (pop carticles)
+	    (when (and articles
 		       (gnus-check-server
 			(gnus-find-method-for-group cgroup) t)
-		       (gnus-request-group cgroup t))
+		       (gnus-request-group cgroup t)
-	      (setq prefix (gnus-group-real-prefix cgroup))
+		       (setq prefix (gnus-group-real-prefix cgroup))
-	      (when (setq result (gnus-retrieve-headers
+		       ;; FIX FIX FIX we want to check the cache!
-				  (list (caddr article)) cgroup nil))
+		       ;; This is probably evil if people have set
-		(set-buffer nntp-server-buffer)
+		       ;; gnus-use-cache to nil themselves, but I
-		(if (zerop (buffer-size))
+		       ;; have no way of finding the true value of it.
-		    (nconc (assq cgroup unfetched) (list (caddr article)))
+		       (let ((gnus-use-cache t))
-		  ;; If we got HEAD headers, we convert them into NOV
+			 (setq result (gnus-retrieve-headers
-		  ;; headers.  This is slow, inefficient and, come to think
+				       articles cgroup nil))))
-		  ;; of it, downright evil.  So sue me.  I couldn't be
+	    (set-buffer nntp-server-buffer)
-		  ;; bothered to write a header parse routine that could
+	    ;; If we got HEAD headers, we convert them into NOV
-		  ;; parse a mixed HEAD/NOV buffer.
+	    ;; headers.  This is slow, inefficient and, come to think
-		  (when (eq result 'headers)
+	    ;; of it, downright evil.  So sue me.  I couldn't be
-		    (nnvirtual-convert-headers))
+	    ;; bothered to write a header parse routine that could
-		  (goto-char (point-min))
+	    ;; parse a mixed HEAD/NOV buffer.
-		  (while (not (eobp))
+	    (when (eq result 'headers)
-		    (delete-region
+	      (nnvirtual-convert-headers))
-		     (point) (progn (read nntp-server-buffer) (point)))
+	    (goto-char (point-min))
-		    (princ (car article) (current-buffer))
+	    (while (not (eobp))
+	      (delete-region (point)
+			     (progn
+			       (setq carticle (read nntp-server-buffer))
+			       (point)))
+	      ;; We remove this article from the articles list, if
+	      ;; anything is left in the articles list after going through
+	      ;; the entire buffer, then those articles have been
+	      ;; expired or canceled, so we appropriately update the
+	      ;; component group below.  They should be coming up
+	      ;; generally in order, so this shouldn't be slow.
+	      (setq articles (delq carticle articles))
+	      (setq article (nnvirtual-reverse-map-article cgroup carticle))
+	      (if (null article)
+		  ;; This line has no reverse mapping, that means it
+		  ;; was an extra article reference returned by nntp.
+		  (progn
 		    (beginning-of-line)
-		    (looking-at
+		    (delete-region (point) (progn (forward-line 1) (point))))
-		     "[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t")
+		;; Otherwise insert the virtual article number,
-		    (goto-char (match-end 0))
+		;; and clean up the xrefs.
-		    (or (search-forward
+		(princ article nntp-server-buffer)
-			 "\t" (save-excursion (end-of-line) (point)) t)
+		(nnvirtual-update-xref-header cgroup carticle
-			(end-of-line))
+					      prefix system-name)
-		    (while (= (char-after (1- (point))) ? )
+		(forward-line 1))
-		      (forward-char -1)
+	      )
-		      (delete-char 1))
-		    (if (eolp)
+	    (set-buffer vbuf)
-			(progn
+	    (goto-char (point-max))
-			  (end-of-line)
+	    (insert-buffer-substring nntp-server-buffer))
-			  (or (= (char-after (1- (point))) ?\t)
+	    ;; Anything left in articles is expired or canceled.
-			      (insert ?\t))
+	    ;; Could be smart and not tell it about articles already known?
-			  (insert "Xref: " system-name " " cgroup ":")
+	    (when articles
-			  (princ (caddr article) (current-buffer))
+	      (gnus-group-make-articles-read cgroup articles))
-			  (insert "\t"))
+	    )
-		      (insert "Xref: " system-name " " cgroup ":")
-		      (princ (caddr article) (current-buffer))
-		      (insert " ")
-		      (if (not (string= "" prefix))
-			  (while (re-search-forward
-				  "[^ ]+:[0-9]+"
-				  (save-excursion (end-of-line) (point)) t)
-			    (save-excursion
-			      (goto-char (match-beginning 0))
-			      (insert prefix))))
-		      (end-of-line)
-		      (or (= (char-after (1- (point))) ?\t)
-			  (insert ?\t)))
-		    (forward-line 1))
-		  (set-buffer vbuf)
-		  (goto-char (point-max))
-		  (insert-buffer-substring nntp-server-buffer)))))
-	  ;; In case some of the articles have expired or been
-	  ;; cancelled, we have to mark them as read in the
-	  ;; component group.
-	  (while unfetched
-	    (when (cdar unfetched)
-	      (gnus-group-make-articles-read
-	       (caar unfetched) (sort (cdar unfetched) '<)))
-	    (setq unfetched (cdr unfetched)))
 	  ;; The headers are ready for reading, so they are inserted into
 	  ;; the nntp-server-buffer, which is where Gnus expects to find
 	  ;; them.
 	  (prog1
 	      (save-excursion
 		(set-buffer nntp-server-buffer)
 		(erase-buffer)
 		(insert-buffer-substring vbuf)
+		;; FIX FIX FIX, we should be able to sort faster than
+		;; this if needed, since each cgroup is sorted, we just
+		;; need to merge
+		(sort-numeric-fields 1 (point-min) (point-max))
 		'nov)
 	    (kill-buffer vbuf)))))))
 (deffoo nnvirtual-request-article (article &optional group server buffer)
 (when (and (nnvirtual-possibly-change-server server)
 	     (numberp article))
-(let* ((amap (assq article nnvirtual-mapping))
+(let* ((amap (nnvirtual-map-article article))
-	   (cgroup (cadr amap)))
+	   (cgroup (car amap)))
 (cond
 ((not amap)
 	(nnheader-report 'nnvirtual "No such article: %s" article))
 ((not (gnus-check-group cgroup))
 	(nnheader-report
 	(nnheader-report 'nnvirtual "Can't open component group %s" cgroup))
 (t
 	(if buffer
 	    (save-excursion
 	      (set-buffer buffer)
-	      (gnus-request-article-this-buffer (caddr amap) cgroup))
+	      (gnus-request-article-this-buffer (cdr amap) cgroup))
-	  (gnus-request-article (caddr amap) cgroup)))))))
+	  (gnus-request-article (cdr amap) cgroup)))))))
 (deffoo nnvirtual-open-server (server &optional defs)
 (unless (assq 'nnvirtual-component-regexp defs)
 (push `(nnvirtual-component-regexp ,server)
 	  defs))
 (nnoo-change-server 'nnvirtual server defs)
 (if nnvirtual-component-groups
 t
-(setq nnvirtual-mapping nil)
+(setq nnvirtual-mapping-table nil
-;; Go through the newsrc alist and find all component groups.
+	  nnvirtual-mapping-offsets nil
-(let ((newsrc (cdr gnus-newsrc-alist))
+	  nnvirtual-mapping-len 0
-	  group)
+	  nnvirtual-mapping-reads nil
-(while (setq group (car (pop newsrc)))
+	  nnvirtual-mapping-marks nil
-	(when (string-match nnvirtual-component-regexp group) ; Match
+	  nnvirtual-info-installed nil)
-	  ;; Add this group to the list of component groups.
+(when nnvirtual-component-regexp
-	  (setq nnvirtual-component-groups
+;; Go through the newsrc alist and find all component groups.
-		(cons group (delete group nnvirtual-component-groups))))))
+(let ((newsrc (cdr gnus-newsrc-alist))
+	    group)
+	(while (setq group (car (pop newsrc)))
+	  (when (string-match nnvirtual-component-regexp group) ; Match
+	    ;; Add this group to the list of component groups.
+	    (setq nnvirtual-component-groups
+		  (cons group (delete group nnvirtual-component-groups)))))))
 (if (not nnvirtual-component-groups)
 	(nnheader-report 'nnvirtual "No component groups: %s" server)
 t)))
 (deffoo nnvirtual-request-group (group &optional server dont-check)
 (nnvirtual-possibly-change-server server)
 (setq nnvirtual-component-groups
 	(delete (nnvirtual-current-group) nnvirtual-component-groups))
 (cond
 ((null nnvirtual-component-groups)
 (setq nnvirtual-current-group nil)
 (nnheader-report 'nnvirtual "No component groups in %s" group))
 (t
-(unless dont-check
+(when (or (not dont-check)
+	      nnvirtual-always-rescan)
 (nnvirtual-create-mapping))
 (setq nnvirtual-current-group group)
-(let ((len (length nnvirtual-mapping)))
+(nnheader-insert "211 %d 1 %d %s\n"
-(nnheader-insert "211 %d 1 %d %s\n" len len group)))))
+		     nnvirtual-mapping-len nnvirtual-mapping-len group))))
 (deffoo nnvirtual-request-type (group &optional article)
 (if (not article)
 'unknown
-(let ((mart (assq article nnvirtual-mapping)))
+(let ((mart (nnvirtual-map-article article)))
 (when mart
-	(gnus-request-type (cadr mart) (car mart))))))
+	(gnus-request-type (car mart) (cdr mart))))))
 (deffoo nnvirtual-request-update-mark (group article mark)
-(let* ((nart (assq article nnvirtual-mapping))
+(let* ((nart (nnvirtual-map-article article))
-	 (cgroup (cadr nart))
+	 (cgroup (car nart))
 	 ;; The component group might be a virtual group.
-	 (nmark (gnus-request-update-mark cgroup (caddr nart) mark)))
+	 (nmark (gnus-request-update-mark cgroup (cdr nart) mark)))
 (when (and nart
 	       (= mark nmark)
 	       (gnus-group-auto-expirable-p cgroup))
 (setq mark gnus-expirable-mark)))
 mark)
 (deffoo nnvirtual-close-group (group &optional server)
-(when (nnvirtual-possibly-change-server server)
+(when (and (nnvirtual-possibly-change-server server)
-;; Copy (un)read articles.
+	     (not (gnus-ephemeral-group-p (nnvirtual-current-group))))
-(nnvirtual-update-reads)
+(nnvirtual-update-read-and-marked t t))
-;; We copy the marks from this group to the component
-;; groups here.
-(nnvirtual-update-marked))
 t)
-(deffoo nnvirtual-request-list (&optional server)
+(deffoo nnvirtual-request-list (&optional server)
 (nnheader-report 'nnvirtual "LIST is not implemented."))
 (deffoo nnvirtual-request-newgroups (date &optional server)
 (nnheader-report 'nnvirtual "NEWGROUPS is not supported."))
 (deffoo nnvirtual-request-list-newsgroups (&optional server)
 (nnheader-report 'nnvirtual "LIST NEWSGROUPS is not implemented."))
 (deffoo nnvirtual-request-update-info (group info &optional server)
-(when (nnvirtual-possibly-change-server server)
+(when (and (nnvirtual-possibly-change-server server)
-(let ((map nnvirtual-mapping)
+	     (not nnvirtual-info-installed))
-	  (marks (mapcar (lambda (m) (list (cdr m))) gnus-article-mark-lists))
+;; Install the precomputed lists atomically, so the virtual group
-	  reads mr m op)
+;; is not left in a half-way state in case of C-g.
-;; Go through the mapping.
+(gnus-atomic-progn
-(while map
+(setcar (cddr info) nnvirtual-mapping-reads)
-	(unless (nth 3 (setq m (pop map)))
-	  ;; Read article.
-	  (push (car m) reads))
-	;; Copy marks.
-	(when (setq mr (nth 4 m))
-	  (while mr
-	    (setcdr (setq op (assq (pop mr) marks)) (cons (car m) (cdr op))))))
-;; Compress the marks and the reads.
-(setq mr marks)
-(while mr
-	(setcdr (car mr) (gnus-compress-sequence (sort (cdr (pop mr)) '<))))
-(setcar (cddr info) (gnus-compress-sequence (nreverse reads)))
-;; Remove empty marks lists.
-(while (and marks (not (cdar marks)))
-	(setq marks (cdr marks)))
-(setq mr marks)
-(while (cdr mr)
-	(if (cdadr mr)
-	    (setq mr (cdr mr))
-	  (setcdr mr (cddr mr))))
-;; Enter these new marks into the info of the group.
 (if (nthcdr 3 info)
-	  (setcar (nthcdr 3 info) marks)
+	  (setcar (nthcdr 3 info) nnvirtual-mapping-marks)
-	;; Add the marks lists to the end of the info.
+	(when nnvirtual-mapping-marks
-	(when marks
+	  (setcdr (nthcdr 2 info) (list nnvirtual-mapping-marks))))
-	  (setcdr (nthcdr 2 info) (list marks))))
+(setq nnvirtual-info-installed t))
-t)))
+t))
 (deffoo nnvirtual-catchup-group (group &optional server all)
-(nnvirtual-possibly-change-server server)
+(when (and (nnvirtual-possibly-change-server server)
-(let ((gnus-group-marked (copy-sequence nnvirtual-component-groups))
+	     (not (gnus-ephemeral-group-p (nnvirtual-current-group))))
-	(gnus-expert-user t))
+;; copy over existing marks first, in case they set anything
-;; Make sure all groups are activated.
+(nnvirtual-update-read-and-marked nil nil)
-(mapcar
+;; do a catchup on all component groups
-(lambda (g)
+(let ((gnus-group-marked (copy-sequence nnvirtual-component-groups))
-(when (not (numberp (car (gnus-gethash g gnus-newsrc-hashtb))))
+	  (gnus-expert-user t))
-	 (gnus-activate-group g)))
+;; Make sure all groups are activated.
-nnvirtual-component-groups)
+(mapcar
-(save-excursion
+(lambda (g)
-(set-buffer gnus-group-buffer)
+	 (when (not (numberp (car (gnus-gethash g gnus-newsrc-hashtb))))
-(gnus-group-catchup-current nil all))))
+	   (gnus-activate-group g)))
+nnvirtual-component-groups)
+(save-excursion
+	(set-buffer gnus-group-buffer)
+	(gnus-group-catchup-current nil all)))))
 (deffoo nnvirtual-find-group-art (group article)
 "Return the real group and article for virtual GROUP and ARTICLE."
-(let ((mart (assq article nnvirtual-mapping)))
+(nnvirtual-map-article article))
-(when mart
-(cons (cadr mart) (caddr mart)))))
 ;;; Internal functions.
 (defun nnvirtual-convert-headers ()
 	   header)
 (erase-buffer)
 (while (setq header (pop headers))
 	(nnheader-insert-nov header)))))
+(defun nnvirtual-update-xref-header (group article prefix system-name)
+"Edit current NOV header in current buffer to have an xref to the component group, and also server prefix any existing xref lines."
+;; Move to beginning of Xref field, creating a slot if needed.
+(beginning-of-line)
+(looking-at
+"[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t")
+(goto-char (match-end 0))
+(unless (search-forward "\t" (point-at-eol) 'move)
+(insert "\t"))
+;; Remove any spaces at the beginning of the Xref field.
+(while (= (char-after (1- (point))) ? )
+(forward-char -1)
+(delete-char 1))
+(insert "Xref: " system-name " " group ":")
+(princ article (current-buffer))
+;; If there were existing xref lines, clean them up to have the correct
+;; component server prefix.
+(let ((xref-end (save-excursion
+		    (search-forward "\t" (point-at-eol) 'move)
+		    (point)))
+	(len (length prefix)))
+(unless (= (point) xref-end)
+(insert " ")
+(when (not (string= "" prefix))
+	(while (re-search-forward "[^ ]+:[0-9]+" xref-end t)
+	  (save-excursion
+	    (goto-char (match-beginning 0))
+	    (insert prefix))
+	  (setq xref-end (+ xref-end len)))
+	)))
+;; Ensure a trailing \t.
+(end-of-line)
+(or (= (char-after (1- (point))) ?\t)
+(insert ?\t)))
 (defun nnvirtual-possibly-change-server (server)
 (or (not server)
 (nnoo-current-server-p 'nnvirtual server)
 (nnvirtual-open-server server)))
-(defun nnvirtual-update-marked ()
-"Copy marks from the virtual group to the component groups."
+(defun nnvirtual-update-read-and-marked (read-p update-p)
-(let ((mark-lists gnus-article-mark-lists)
+"Copy marks from the virtual group to the component groups.
-	(marks (gnus-info-marks (gnus-get-info (nnvirtual-current-group))))
+If READ-P is not nil, update the (un)read status of the components.
-	type list mart cgroups)
+If UPDATE-P is not nil, call gnus-group-update-group on the components."
-(while (setq type (cdr (pop mark-lists)))
+(let ((unreads (and read-p
-(setq list (gnus-uncompress-range (cdr (assq type marks))))
+		      (nnvirtual-partition-sequence
-(setq cgroups
+		       (gnus-list-of-unread-articles
-	    (mapcar (lambda (g) (list g)) nnvirtual-component-groups))
+			(nnvirtual-current-group)))))
-(while list
+	(type-marks (mapcar (lambda (ml)
-	(nconc (assoc (cadr (setq mart (assq (pop list) nnvirtual-mapping)))
+			      (cons (car ml)
-		      cgroups)
+				    (nnvirtual-partition-sequence (cdr ml))))
-	       (list (caddr mart))))
+			    (gnus-info-marks (gnus-get-info
-(while cgroups
+					      (nnvirtual-current-group)))))
-	(gnus-add-marked-articles
+	mark type groups carticles info entry)
-	 (caar cgroups) type (cdar cgroups) nil t)
-	(gnus-group-update-group (car (pop cgroups)) t)))))
+;; Ok, atomically move all of the (un)read info, clear any old
+;; marks, and move all of the current marks.  This way if someone
-(defun nnvirtual-update-reads ()
+;; hits C-g, you won't leave the component groups in a half-way state.
-"Copy (un)reads from the current group to the component groups."
+(gnus-atomic-progn
-(let ((groups (mapcar (lambda (g) (list g)) nnvirtual-component-groups))
+;; move (un)read
-	(articles (gnus-list-of-unread-articles
+(let ((gnus-newsgroup-active nil)) ;workaround guns-update-read-articles
-		   (nnvirtual-current-group)))
+	(while (setq entry (pop unreads))
-	m)
+	  (gnus-update-read-articles (car entry) (cdr entry))))
-(while articles
-(setq m (assq (pop articles) nnvirtual-mapping))
+;; clear all existing marks on the component groups
-(nconc (assoc (nth 1 m) groups) (list (nth 2 m))))
+(setq groups nnvirtual-component-groups)
 (while groups
-(gnus-update-read-articles (caar groups) (cdr (pop groups))))))
+	(when (and (setq info (gnus-get-info (pop groups)))
+		   (gnus-info-marks info))
+	  (gnus-info-set-marks info nil)))
+;; Ok, currently type-marks is an assq list with keys of a mark type,
+;; with data of an assq list with keys of component group names
+;; and the articles which correspond to that key/group pair.
+(while (setq mark (pop type-marks))
+	(setq type (car mark))
+	(setq groups (cdr mark))
+	(while (setq carticles (pop groups))
+	  (gnus-add-marked-articles (car carticles) type (cdr carticles)
+				    nil t))))
+;; possibly update the display, it is really slow
+(when update-p
+(setq groups nnvirtual-component-groups)
+(while groups
+	(gnus-group-update-group (pop groups) t)))
+))
 (defun nnvirtual-current-group ()
 "Return the prefixed name of the current nnvirtual group."
 (concat "nnvirtual:" nnvirtual-current-group))
-(defsubst nnvirtual-marks (article marks)
-"Return a list of mark types for ARTICLE."
-(let (out)
+;;; This is currently O(kn^2) to merge n lists of length k.
-(while marks
+;;; You could do it in O(knlogn), but we have a small n, and the
-(when (memq article (cdar marks))
+;;; overhead of the other approach is probably greater.
-	(push (caar marks) out))
+(defun nnvirtual-merge-sorted-lists (&rest lists)
-(setq marks (cdr marks)))
+"Merge many sorted lists of numbers."
-out))
+(if (null (cdr lists))
+(car lists)
+(apply 'nnvirtual-merge-sorted-lists
+	   (merge 'list (car lists) (cadr lists) '<)
+	   (cddr lists))))
+;;; We map between virtual articles and real articles in a manner
+;;; which keeps the size of the virtual active list the same as
+;;; the sum of the component active lists.
+;;; To achieve fair mixing of the groups, the last article in
+;;; each of N component groups will be in the the last N articles
+;;; in the virtual group.
+;;; If you have 3 components A, B and C, with articles 1-8, 1-5, and 6-7
+;;; resprectively, then the virtual article numbers look like:
+;;;
+;;;  1  2  3  4  5  6  7  8  9  10 11 12 13 14 15
+;;;  A1 A2 A3 A4 B1 A5 B2 A6 B3 A7 B4 C6 A8 B5 C7
+;;; To compute these mappings we generate a couple tables and then
+;;; do some fast operations on them.  Tables for the example above:
+;;;
+;;; Offsets - [(A 0) (B -3) (C -1)]
+;;;
+;;;               a  b  c  d  e
+;;; Mapping - ([  3  0  1  3  0 ]
+;;;            [  6  3  2  9  3 ]
+;;;            [  8  6  3 15  9 ])
+;;;
+;;; (note column 'e' is different in real algorithm, which is slightly
+;;;  different than described here, but this gives you the methodology.)
+;;;
+;;; The basic idea is this, when going from component->virtual, apply
+;;; the appropriate offset to the article number.  Then search the first
+;;; column of the table for a row where 'a' is less than or equal to the
+;;; modified number.  You can see that only group A can therefore go to
+;;; the first row, groups A and B to the second, and all to the last.
+;;; The third column of the table is telling us the number of groups
+;;; which might be able to reach that row (it might increase by more than
+;;; 1 if several groups have the same size).
+;;; Then column 'b' provides an additional offset you apply when you have
+;;; found the correct row.  You then multiply by 'c' and add on the groups
+;;; _position_ in the offset table.  The basic idea here is that on
+;;; any given row we are going to map back and forth using X'=X*c+Y and
+;;; X=(X'/c), Y=(X' mod c).  Then once you've done this transformation,
+;;; you apply a final offset from column 'e' to give the virtual article.
+;;;
+;;; Going the other direction, you instead search on column 'd' instead
+;;; of 'a', and apply everything in reverse order.
+;;; Convert component -> virtual:
+;;; set num = num - Offset(group)
+;;; find first row in Mapping where num <= 'a'
+;;; num = (num-'b')*c + Position(group) + 'e'
+;;; Convert virtual -> component:
+;;; find first row in Mapping where num <= 'd'
+;;; num = num - 'e'
+;;; group_pos = num mod 'c'
+;;; num = (num / 'c') + 'b' + Offset(group_pos)
+;;; Easy no? :)
+;;;
+;;; Well actually, you need to keep column e offset smaller by the 'c'
+;;; column for that line, and always add 1 more when going from
+;;; component -> virtual.  Otherwise you run into a problem with
+;;; unique reverse mapping.
+(defun nnvirtual-map-article (article)
+"Return a cons of the component group and article corresponding to the given virtual ARTICLE."
+(let ((table nnvirtual-mapping-table)
+	entry group-pos)
+(while (and table
+		(> article (aref (car table) 3)))
+(setq table (cdr table)))
+(when (and table
+	       (> article 0))
+(setq entry (car table))
+(setq article (- article (aref entry 4) 1))
+(setq group-pos (mod article (aref entry 2)))
+(cons (car (aref nnvirtual-mapping-offsets group-pos))
+	    (+ (/ article (aref entry 2))
+	       (aref entry 1)
+	       (cdr (aref nnvirtual-mapping-offsets group-pos)))
+	    ))
+))
+(defun nnvirtual-reverse-map-article (group article)
+"Return the virtual article number corresponding to the given component GROUP and ARTICLE."
+(let ((table nnvirtual-mapping-table)
+	(group-pos 0)
+	entry)
+(while (not (string= group (car (aref nnvirtual-mapping-offsets
+					  group-pos))))
+(setq group-pos (1+ group-pos)))
+(setq article (- article (cdr (aref nnvirtual-mapping-offsets
+					group-pos))))
+(while (and table
+		(> article (aref (car table) 0)))
+(setq table (cdr table)))
+(setq entry (car table))
+(when (and entry
+	       (> article 0)
+	       (< group-pos (aref entry 2))) ; article not out of range below
+(+ (aref entry 4)
+	 group-pos
+	 (* (- article (aref entry 1))
+	    (aref entry 2))
+	 1))
+))
+(defun nnvirtual-reverse-map-sequence (group articles)
+"Return list of virtual article numbers for all ARTICLES in GROUP.
+The ARTICLES should be sorted, and can be a compressed sequence.
+If any of the article numbers has no corresponding virtual article,
+then it is left out of the result."
+(when (numberp (cdr-safe articles))
+(setq articles (list articles)))
+(let (result a i j new-a)
+(while (setq a (pop articles))
+(if (atom a)
+	  (setq i a
+		j a)
+	(setq i (car a)
+	      j (cdr a)))
+(while (<= i j)
+	;; If this is slow, you can optimize by moving article checking
+	;; into here.  You don't have to recompute the group-pos,
+	;; nor scan the table every time.
+	(when (setq new-a (nnvirtual-reverse-map-article group i))
+	  (push new-a result))
+	(setq i (1+ i))))
+(nreverse result)))
+(defun nnvirtual-partition-sequence (articles)
+"Return an association list of component article numbers.
+These are indexed by elements of nnvirtual-component-groups, based on
+the sequence ARTICLES of virtual article numbers.  ARTICLES should be
+sorted, and can be a compressed sequence. If any of the article
+numbers has no corresponding component article, then it is left out of
+the result."
+(when (numberp (cdr-safe articles))
+(setq articles (list articles)))
+(let ((carticles (mapcar (lambda (g) (list g))
+			   nnvirtual-component-groups))
+	a i j article entry)
+(while (setq a (pop articles))
+(if (atom a)
+	  (setq i a
+		j a)
+	(setq i (car a)
+	      j (cdr a)))
+(while (<= i j)
+	(when (setq article (nnvirtual-map-article i))
+	  (setq entry (assoc (car article) carticles))
+	  (setcdr entry (cons (cdr article) (cdr entry))))
+	(setq i (1+ i))))
+(mapc '(lambda (x) (setcdr x (nreverse (cdr x))))
+	  carticles)
+carticles))
 (defun nnvirtual-create-mapping ()
-"Create an article mapping for the current group."
+"Build the tables necessary to map between component (group, article) to virtual article.
-(let* ((div nil)
+Generate the set of read messages and marks for the virtual group
-	 m marks list article unreads marks active
+based on the marks on the component groups."
-	 (map (sort
+(let ((cnt 0)
-	       (apply
+	(tot 0)
-		'nconc
+	(M 0)
-		(mapcar
+	(i 0)
-		 (lambda (g)
+	actives all-unreads all-marks
-		   (when (and (setq active (gnus-activate-group g))
+	active min max size unreads marks
-			      (> (cdr active) (car active)))
+	next-M next-tot
-		     (setq unreads (gnus-list-of-unread-articles g)
+	reads beg)
-			   marks (gnus-uncompress-marks
+;; Ok, we loop over all component groups and collect a lot of
-				  (gnus-info-marks (gnus-get-info g))))
+;; information:
-		     (when gnus-use-cache
+;; Into actives we place (g size max), where size is max-min+1.
-		       (push (cons 'cache (gnus-cache-articles-in-group g))
+;; Into all-unreads we put (g unreads).
-			     marks))
+;; Into all-marks we put (g marks).
-		     (setq div (/ (float (car active))
+;; We also increment cnt and tot here, and compute M (max of sizes).
-				  (if (zerop (cdr active))
+(mapc (lambda (g)
-				      1 (cdr active))))
+	    (setq active (gnus-activate-group g)
-		     (mapcar (lambda (n)
+		  min (car active)
-			       (list (* div (- n (car active)))
+		  max (cdr active))
-				     g n (and (memq n unreads) t)
+	    (when (and active (>= max min) (not (zerop max)))
-				     (inline (nnvirtual-marks n marks))))
+	      ;; store active information
-			     (gnus-uncompress-range active))))
+	      (push (list g (- max min -1) max) actives)
-		 nnvirtual-component-groups))
+	      ;; collect unread/mark info for later
-	       (lambda (m1 m2)
+	      (setq unreads (gnus-list-of-unread-articles g))
-		 (< (car m1) (car m2)))))
+	      (setq marks (gnus-info-marks (gnus-get-info g)))
-	 (i 0))
+	      (when gnus-use-cache
-(setq nnvirtual-mapping map)
+		(push (cons 'cache
-;; Set the virtual article numbers.
+			    (gnus-cache-articles-in-group g))
-(while (setq m (pop map))
+		      marks))
-(setcar m (setq article (incf i))))))
+	      (push (cons g unreads) all-unreads)
+	      (push (cons g marks) all-marks)
+	      ;; count groups, total #articles, and max size
+	      (setq size (- max min -1))
+	      (setq cnt (1+ cnt)
+		    tot (+ tot size)
+		    M (max M size))))
+	  nnvirtual-component-groups)
+;; Number of articles in the virtual group.
+(setq nnvirtual-mapping-len tot)
+;; We want the actives list sorted by size, to build the tables.
+(setq actives (sort actives (lambda (g1 g2) (< (nth 1 g1) (nth 1 g2)))))
+;; Build the offset table.  Largest sized groups are at the front.
+(setq nnvirtual-mapping-offsets
+	  (vconcat
+	   (nreverse
+	    (mapcar (lambda (entry)
+		      (cons (nth 0 entry)
+			    (- (nth 2 entry) M)))
+		    actives))))
+;; Build the mapping table.
+(setq nnvirtual-mapping-table nil)
+(setq actives (mapcar (lambda (entry) (nth 1 entry)) actives))
+(while actives
+(setq size (car actives))
+(setq next-M (- M size))
+(setq next-tot (- tot (* cnt size)))
+;; make current row in table
+(push (vector M next-M cnt tot (- next-tot cnt))
+	    nnvirtual-mapping-table)
+;; update M and tot
+(setq M next-M)
+(setq tot next-tot)
+;; subtract the current size from all entries.
+(setq actives (mapcar (lambda (x) (- x size)) actives))
+;; remove anything that went to 0.
+(while (and actives
+		  (= (car actives) 0))
+	(pop actives)
+	(setq cnt (- cnt 1))))
+;; Now that the mapping tables are generated, we can convert
+;; and combine the separate component unreads and marks lists
+;; into single lists of virtual article numbers.
+(setq unreads (apply 'nnvirtual-merge-sorted-lists
+			 (mapcar (lambda (x)
+				   (nnvirtual-reverse-map-sequence
+				    (car x) (cdr x)))
+				 all-unreads)))
+(setq marks (mapcar
+		 (lambda (type)
+		   (cons (cdr type)
+			 (gnus-compress-sequence
+			  (apply
+			   'nnvirtual-merge-sorted-lists
+			   (mapcar (lambda (x)
+				     (nnvirtual-reverse-map-sequence
+				      (car x)
+				      (cdr (assq (cdr type) (cdr x)))))
+				   all-marks)))))
+		 gnus-article-mark-lists))
+;; Remove any empty marks lists, and store.
+(setq nnvirtual-mapping-marks (delete-if-not 'cdr marks))
+;; We need to convert the unreads to reads.  We compress the
+;; sequence as we go, otherwise it could be huge.
+(while (and (<= (incf i) nnvirtual-mapping-len)
+		unreads)
+(if (= i (car unreads))
+	  (setq unreads (cdr unreads))
+	;; try to get a range.
+	(setq beg i)
+	(while (and (<= (incf i) nnvirtual-mapping-len)
+		    (not (= i (car unreads)))))
+	(setq i (- i 1))
+	(if (= i beg)
+	    (push i reads)
+	  (push (cons beg i) reads))
+	))
+(when (<= i nnvirtual-mapping-len)
+(if (= i nnvirtual-mapping-len)
+	  (push i reads)
+	(push (cons i nnvirtual-mapping-len) reads)))
+;; Store the reads list for later use.
+(setq nnvirtual-mapping-reads (nreverse reads))
+;; Throw flag to show we changed the info.
+(setq nnvirtual-info-installed nil)
+))
 (provide 'nnvirtual)
 ;;; nnvirtual.el ends here

Mercurial > hg > xemacs-beta

comparison lisp/gnus/nnvirtual.el @ 16:0293115a14e9 r19-15b91