--- a/lisp/gnus/nnvirtual.el	Mon Aug 13 09:00:04 2007 +0200
+++ b/lisp/gnus/nnvirtual.el	Mon Aug 13 09:02:59 2007 +0200
@@ -1,8 +1,7 @@
 ;;; nnvirtual.el --- virtual newsgroups access for Gnus
-;; Copyright (C) 1994,95,96,97 Free Software Foundation, Inc.
+;; Copyright (C) 1994,95,96 Free Software Foundation, Inc.
 
-;; Author: David Moore <dmoore@ucsd.edu>
-;;	Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
+;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
 ;; 	Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
 ;; Keywords: news
 
@@ -26,7 +25,7 @@
 ;;; 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:
@@ -35,9 +34,6 @@
 (require 'nnheader)
 (require 'gnus)
 (require 'nnoo)
-(require 'gnus-util)
-(require 'gnus-start)
-(require 'gnus-sum)
 (eval-when-compile (require 'cl))
 
 (nnoo-declare nnvirtual)
@@ -52,33 +48,13 @@
 (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 1.1")
+(defconst nnvirtual-version "nnvirtual 1.0")
 
 (defvoo nnvirtual-current-group 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-component-groups nil)
+(defvoo nnvirtual-mapping nil)
 
 (defvoo nnvirtual-status-string "")
 
@@ -91,7 +67,6 @@
 
 (nnoo-define-basics nnvirtual)
 
-
 (deffoo nnvirtual-retrieve-headers (articles &optional newsgroup
 					     server fetch-old)
   (when (nnvirtual-possibly-change-server server)
@@ -100,73 +75,80 @@
       (erase-buffer)
       (if (stringp (car articles))
 	  'headers
-	(let ((vbuf (nnheader-set-temp-buffer
+	(let ((vbuf (nnheader-set-temp-buffer 
 		     (get-buffer-create " *virtual headers*")))
-	      (carticles (nnvirtual-partition-sequence articles))
+	      (unfetched (mapcar (lambda (g) (list g))
+				 nnvirtual-component-groups))
 	      (system-name (system-name))
-	      cgroup carticle article result prefix)
-	  (while carticles
-	    (setq cgroup (caar carticles))
-	    (setq articles (cdar carticles))
-	    (pop carticles)
-	    (when (and articles
+	      cgroup article result prefix)
+	  (while articles
+	    (setq article (assq (pop articles) nnvirtual-mapping))
+	    (when (and (setq cgroup (cadr article))
 		       (gnus-check-server
 			(gnus-find-method-for-group cgroup) t)
-		       (gnus-request-group cgroup t)
-		       (setq prefix (gnus-group-real-prefix cgroup))
-		       ;; FIX FIX FIX we want to check the cache!
-		       ;; This is probably evil if people have set
-		       ;; gnus-use-cache to nil themselves, but I
-		       ;; have no way of finding the true value of it.
-		       (let ((gnus-use-cache t))
-			 (setq result (gnus-retrieve-headers
-				       articles cgroup nil))))
-	    (set-buffer nntp-server-buffer)
-	    ;; If we got HEAD headers, we convert them into NOV
-	    ;; headers.  This is slow, inefficient and, come to think
-	    ;; of it, downright evil.  So sue me.  I couldn't be
-	    ;; bothered to write a header parse routine that could
-	    ;; parse a mixed HEAD/NOV buffer.
-	    (when (eq result 'headers)
-	      (nnvirtual-convert-headers))
-	    (goto-char (point-min))
-	    (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
+		       (gnus-request-group cgroup t))
+	      (setq prefix (gnus-group-real-prefix cgroup))
+	      (when (setq result (gnus-retrieve-headers 
+				  (list (caddr article)) cgroup nil))
+		(set-buffer nntp-server-buffer)
+		(if (zerop (buffer-size))
+		    (nconc (assq cgroup unfetched) (list (caddr article)))
+		  ;; If we got HEAD headers, we convert them into NOV
+		  ;; headers.  This is slow, inefficient and, come to think
+		  ;; of it, downright evil.  So sue me.  I couldn't be
+		  ;; bothered to write a header parse routine that could
+		  ;; parse a mixed HEAD/NOV buffer.
+		  (when (eq result 'headers)
+		    (nnvirtual-convert-headers))
+		  (goto-char (point-min))
+		  (while (not (eobp))
+		    (delete-region 
+		     (point) (progn (read nntp-server-buffer) (point)))
+		    (princ (car article) (current-buffer))
 		    (beginning-of-line)
-		    (delete-region (point) (progn (forward-line 1) (point))))
-		;; Otherwise insert the virtual article number,
-		;; and clean up the xrefs.
-		(princ article nntp-server-buffer)
-		(nnvirtual-update-xref-header cgroup carticle
-					      prefix system-name)
-		(forward-line 1))
-	      )
-
-	    (set-buffer vbuf)
-	    (goto-char (point-max))
-	    (insert-buffer-substring nntp-server-buffer))
-	    ;; Anything left in articles is expired or canceled.
-	    ;; Could be smart and not tell it about articles already known?
-	    (when articles
-	      (gnus-group-make-articles-read cgroup articles))
-	    )
+		    (looking-at 
+		     "[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t[^\t]*\t")
+		    (goto-char (match-end 0))
+		    (or (search-forward 
+			 "\t" (save-excursion (end-of-line) (point)) t)
+			(end-of-line))
+		    (while (= (char-after (1- (point))) ? )
+		      (forward-char -1)
+		      (delete-char 1))
+		    (if (eolp)
+			(progn
+			  (end-of-line)
+			  (or (= (char-after (1- (point))) ?\t)
+			      (insert ?\t))
+			  (insert "Xref: " system-name " " cgroup ":")
+			  (princ (caddr article) (current-buffer))
+			  (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
@@ -176,51 +158,28 @@
 		(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)))))))
 
-
-(defvoo nnvirtual-last-accessed-component-group nil)
-
 (deffoo nnvirtual-request-article (article &optional group server buffer)
-  (when (nnvirtual-possibly-change-server server)
-    (if (stringp article)
-	;; This is a fetch by Message-ID.
-	(cond
-	 ((not nnvirtual-last-accessed-component-group)
-	  (nnheader-report
-	   'nnvirtual "Don't know what server to request from"))
-	 (t
-	  (save-excursion
-	    (when buffer
-	      (set-buffer buffer))
-	    (let ((method (gnus-find-method-for-group
-			   nnvirtual-last-accessed-component-group)))
-	      (funcall (gnus-get-function method 'request-article)
-		       article nil (nth 1 method) buffer)))))
-      ;; This is a fetch by number.
-      (let* ((amap (nnvirtual-map-article article))
-	     (cgroup (car amap)))
-	(cond
-	 ((not amap)
-	  (nnheader-report 'nnvirtual "No such article: %s" article))
-	 ((not (gnus-check-group cgroup))
-	  (nnheader-report
-	   'nnvirtual "Can't open server where %s exists" cgroup))
-	 ((not (gnus-request-group cgroup t))
-	  (nnheader-report 'nnvirtual "Can't open component group %s" cgroup))
-	 (t
-	  (setq nnvirtual-last-accessed-component-group cgroup)
-	  (if buffer
-	      (save-excursion
-		(set-buffer buffer)
-		(gnus-request-article-this-buffer (cdr amap) cgroup))
-	    (gnus-request-article (cdr amap) cgroup))))))))
-
+  (when (and (nnvirtual-possibly-change-server server)
+	     (numberp article))
+    (let* ((amap (assq article nnvirtual-mapping))
+	   (cgroup (cadr amap)))
+      (cond
+       ((not amap)
+	(nnheader-report 'nnvirtual "No such article: %s" article))
+       ((not (gnus-check-group cgroup))
+	(nnheader-report
+	 'nnvirtual "Can't open server where %s exists" cgroup))
+       ((not (gnus-request-group cgroup t))
+	(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 (caddr amap) cgroup)))))))
 
 (deffoo nnvirtual-open-server (server &optional defs)
   (unless (assq 'nnvirtual-component-regexp defs)
@@ -229,26 +188,19 @@
   (nnoo-change-server 'nnvirtual server defs)
   (if nnvirtual-component-groups
       t
-    (setq nnvirtual-mapping-table nil
-	  nnvirtual-mapping-offsets nil
-	  nnvirtual-mapping-len 0
-	  nnvirtual-mapping-reads nil
-	  nnvirtual-mapping-marks nil
-	  nnvirtual-info-installed nil)
-    (when nnvirtual-component-regexp
-      ;; Go through the newsrc alist and find all 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)))))))
+    (setq nnvirtual-mapping nil)
+    ;; Go through the newsrc alist and find all 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
@@ -258,89 +210,103 @@
     (setq nnvirtual-current-group nil)
     (nnheader-report 'nnvirtual "No component groups in %s" group))
    (t
-    (when (or (not dont-check)
-	      nnvirtual-always-rescan)
+    (unless dont-check
       (nnvirtual-create-mapping))
     (setq nnvirtual-current-group group)
-    (nnheader-insert "211 %d 1 %d %s\n"
-		     nnvirtual-mapping-len nnvirtual-mapping-len group))))
-
+    (let ((len (length nnvirtual-mapping)))
+      (nnheader-insert "211 %d 1 %d %s\n" len len group)))))
 
 (deffoo nnvirtual-request-type (group &optional article)
   (if (not article)
       'unknown
-    (let ((mart (nnvirtual-map-article article)))
+    (let ((mart (assq article nnvirtual-mapping)))
       (when mart
-	(gnus-request-type (car mart) (cdr mart))))))
+	(gnus-request-type (cadr mart) (car mart))))))
 
 (deffoo nnvirtual-request-update-mark (group article mark)
-  (let* ((nart (nnvirtual-map-article article))
-	 (cgroup (car nart))
+  (let* ((nart (assq article nnvirtual-mapping))
+	 (cgroup (cadr nart))
 	 ;; The component group might be a virtual group.
-	 (nmark (gnus-request-update-mark cgroup (cdr nart) mark)))
+	 (nmark (gnus-request-update-mark cgroup (caddr 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 (and (nnvirtual-possibly-change-server server)
-	     (not (gnus-ephemeral-group-p (nnvirtual-current-group))))
-    (nnvirtual-update-read-and-marked t t))
+  (when (nnvirtual-possibly-change-server server)
+    ;; Copy (un)read articles.
+    (nnvirtual-update-reads)
+    ;; 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)
+    (let ((map nnvirtual-mapping)
+	  (marks (mapcar (lambda (m) (list (cdr m))) gnus-article-mark-lists))
+	  reads mr m op)
+      ;; Go through the mapping.
+      (while map
+	(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))))
 
-(deffoo nnvirtual-request-update-info (group info &optional server)
-  (when (and (nnvirtual-possibly-change-server server)
-	     (not nnvirtual-info-installed))
-    ;; Install the precomputed lists atomically, so the virtual group
-    ;; is not left in a half-way state in case of C-g.
-    (gnus-atomic-progn
-      (setcar (cddr info) nnvirtual-mapping-reads)
+      ;; Enter these new marks into the info of the group.
       (if (nthcdr 3 info)
-	  (setcar (nthcdr 3 info) nnvirtual-mapping-marks)
-	(when nnvirtual-mapping-marks
-	  (setcdr (nthcdr 2 info) (list nnvirtual-mapping-marks))))
-      (setq nnvirtual-info-installed t))
-    t))
-
+	  (setcar (nthcdr 3 info) marks)
+	;; Add the marks lists to the end of the info.
+	(when marks
+	  (setcdr (nthcdr 2 info) (list marks))))
+      t)))
 
 (deffoo nnvirtual-catchup-group (group &optional server all)
-  (when (and (nnvirtual-possibly-change-server server)
-	     (not (gnus-ephemeral-group-p (nnvirtual-current-group))))
-    ;; copy over existing marks first, in case they set anything
-    (nnvirtual-update-read-and-marked nil nil)
-    ;; do a catchup on all component groups
-    (let ((gnus-group-marked (copy-sequence nnvirtual-component-groups))
-	  (gnus-expert-user t))
-      ;; Make sure all groups are activated.
-      (mapcar
-       (lambda (g)
-	 (when (not (numberp (car (gnus-gethash g gnus-newsrc-hashtb))))
-	   (gnus-activate-group g)))
-       nnvirtual-component-groups)
-      (save-excursion
-	(set-buffer gnus-group-buffer)
-	(gnus-group-catchup-current nil all)))))
-
+  (nnvirtual-possibly-change-server server)
+  (let ((gnus-group-marked (copy-sequence nnvirtual-component-groups))
+	(gnus-expert-user t))
+    ;; Make sure all groups are activated.
+    (mapcar
+     (lambda (g)
+       (when (not (numberp (car (gnus-gethash g gnus-newsrc-hashtb))))
+	 (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."
-  (nnvirtual-map-article article))
+  (let ((mart (assq article nnvirtual-mapping)))
+    (when mart
+      (cons (cadr mart) (caddr mart)))))
 
 
 ;;; Internal functions.
@@ -356,410 +322,87 @@
       (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" (gnus-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" (gnus-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-read-and-marked (read-p update-p)
-  "Copy marks from the virtual group to the component groups.
-If READ-P is not nil, update the (un)read status of the components.
-If UPDATE-P is not nil, call gnus-group-update-group on the components."
-  (when nnvirtual-current-group
-    (let ((unreads (and read-p
-			(nnvirtual-partition-sequence
-			 (gnus-list-of-unread-articles
-			  (nnvirtual-current-group)))))
-	  (type-marks (mapcar (lambda (ml)
-				(cons (car ml)
-				      (nnvirtual-partition-sequence (cdr ml))))
-			      (gnus-info-marks (gnus-get-info
-						(nnvirtual-current-group)))))
-	  mark type groups carticles info entry)
+(defun nnvirtual-update-marked ()
+  "Copy marks from the virtual group to the component groups."
+  (let ((mark-lists gnus-article-mark-lists)
+	(marks (gnus-info-marks (gnus-get-info (nnvirtual-current-group))))
+	type list mart cgroups)
+    (while (setq type (cdr (pop mark-lists)))
+      (setq list (gnus-uncompress-range (cdr (assq type marks))))
+      (setq cgroups 
+	    (mapcar (lambda (g) (list g)) nnvirtual-component-groups))
+      (while list
+	(nconc (assoc (cadr (setq mart (assq (pop list) nnvirtual-mapping)))
+		      cgroups)
+	       (list (caddr mart))))
+      (while cgroups
+	(gnus-add-marked-articles 
+	 (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
-      ;; hits C-g, you won't leave the component groups in a half-way state.
-      (gnus-atomic-progn
-	;; move (un)read
-	(let ((gnus-newsgroup-active nil)) ;workaround guns-update-read-articles
-	  (while (setq entry (pop unreads))
-	    (gnus-update-read-articles (car entry) (cdr entry))))
-
-	;; clear all existing marks on the component groups
-	(setq groups nnvirtual-component-groups)
-	(while 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-update-reads ()
+  "Copy (un)reads from the current group to the component groups."
+  (let ((groups (mapcar (lambda (g) (list g)) nnvirtual-component-groups))
+	(articles (gnus-list-of-unread-articles
+		   (nnvirtual-current-group)))
+	m)
+    (while articles
+      (setq m (assq (pop articles) nnvirtual-mapping))
+      (nconc (assoc (nth 1 m) groups) (list (nth 2 m))))
+    (while groups
+      (gnus-update-read-articles (caar groups) (cdr (pop groups))))))
 
 (defun nnvirtual-current-group ()
   "Return the prefixed name of the current nnvirtual group."
   (concat "nnvirtual:" nnvirtual-current-group))
 
-
-
-;;; This is currently O(kn^2) to merge n lists of length k.
-;;; You could do it in O(knlogn), but we have a small n, and the
-;;; overhead of the other approach is probably greater.
-(defun nnvirtual-merge-sorted-lists (&rest lists)
-  "Merge many sorted lists of numbers."
-  (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))
-    ))
-
-
-(defsubst 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))
-
+(defsubst nnvirtual-marks (article marks)
+  "Return a list of mark types for ARTICLE."
+  (let (out)
+    (while marks
+      (when (memq article (cdar marks))
+	(push (caar marks) out))
+      (setq marks (cdr marks)))
+    out))
 
 (defun nnvirtual-create-mapping ()
-  "Build the tables necessary to map between component (group, article) to virtual article.
-Generate the set of read messages and marks for the virtual group
-based on the marks on the component groups."
-  (let ((cnt 0)
-	(tot 0)
-	(M 0)
-	(i 0)
-	actives all-unreads all-marks
-	active min max size unreads marks
-	next-M next-tot
-	reads beg)
-    ;; Ok, we loop over all component groups and collect a lot of
-    ;; information:
-    ;; Into actives we place (g size max), where size is max-min+1.
-    ;; Into all-unreads we put (g unreads).
-    ;; Into all-marks we put (g marks).
-    ;; We also increment cnt and tot here, and compute M (max of sizes).
-    (mapc (lambda (g)
-	    (setq active (gnus-activate-group g)
-		  min (car active)
-		  max (cdr active))
-	    (when (and active (>= max min) (not (zerop max)))
-	      ;; store active information
-	      (push (list g (- max min -1) max) actives)
-	      ;; collect unread/mark info for later
-	      (setq unreads (gnus-list-of-unread-articles g))
-	      (setq marks (gnus-info-marks (gnus-get-info g)))
-	      (when gnus-use-cache
-		(push (cons 'cache
-			    (gnus-cache-articles-in-group g))
-		      marks))
-	      (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)
-    ))
+  "Create an article mapping for the current group."
+  (let* ((div nil)
+	 m marks list article unreads marks active
+	 (map (sort
+	       (apply 
+		'nconc
+		(mapcar
+		 (lambda (g)
+		   (when (and (setq active (gnus-activate-group g))
+			      (> (cdr active) (car active)))
+		     (setq unreads (gnus-list-of-unread-articles g)
+			   marks (gnus-uncompress-marks
+				  (gnus-info-marks (gnus-get-info g))))
+		     (when gnus-use-cache
+		       (push (cons 'cache (gnus-cache-articles-in-group g))
+			     marks))
+		     (setq div (/ (float (car active)) 
+				  (if (zerop (cdr active))
+				      1 (cdr active))))
+		     (mapcar (lambda (n) 
+			       (list (* div (- n (car active)))
+				     g n (and (memq n unreads) t)
+				     (inline (nnvirtual-marks n marks))))
+			     (gnus-uncompress-range active))))
+		 nnvirtual-component-groups))
+	       (lambda (m1 m2)
+		 (< (car m1) (car m2)))))
+	 (i 0))
+    (setq nnvirtual-mapping map)
+    ;; Set the virtual article numbers.
+    (while (setq m (pop map))
+      (setcar m (setq article (incf i))))))
 
 (provide 'nnvirtual)