X-Git-Url: http://cgit.sxemacs.org/?a=blobdiff_plain;f=lisp%2Fgnus-registry.el;h=879b6708920abcb9293c32cbeace7e1be7bc1112;hb=5add7111f986a9fb399b27ef7eff350eb7ce420a;hp=6c116310307622c108a99a6b2e68565dd8dd5779;hpb=3e382bbff0d64f497fd99a88a3882e3c83b7a225;p=gnus

diff --git a/lisp/gnus-registry.el b/lisp/gnus-registry.el
index 6c1163103..879b67089 100644
--- a/lisp/gnus-registry.el
+++ b/lisp/gnus-registry.el
@@ -1,5 +1,5 @@
 ;;; gnus-registry.el --- article registry for Gnus
-;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
+;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
 ;;        Free Software Foundation, Inc.
 
 ;; Author: Ted Zlatanov <tzz@lifelogs.com>
@@ -24,6 +24,34 @@
 
 ;;; Commentary:
 
+;; This is the gnus-registry.el package, which works with all
+;; backends, not just nnmail (e.g. NNTP).  The major issue is that it
+;; doesn't go across backends, so for instance if an article is in
+;; nnml:sys and you see a reference to it in nnimap splitting, the
+;; article will end up in nnimap:sys
+
+;; gnus-registry.el intercepts article respooling, moving, deleting,
+;; and copying for all backends.  If it doesn't work correctly for
+;; you, submit a bug report and I'll be glad to fix it.  It needs
+;; documentation in the manual (also on my to-do list).
+
+;; Put this in your startup file (~/.gnus.el for instance)
+
+;; (setq gnus-registry-max-entries 2500
+;;       gnus-registry-use-long-group-names t)
+
+;; (gnus-registry-initialize)
+
+;; Then use this in your fancy-split:
+
+;; (: gnus-registry-split-fancy-with-parent)
+
+;; TODO:
+
+;; - get the correct group on spool actions
+
+;; - articles that are spooled to a different backend should be handled
+
 ;;; Code:
 
 (eval-when-compile (require 'cl))
@@ -33,54 +61,665 @@
 (require 'gnus-sum)
 (require 'nnmail)
 
-(defvar gnus-registry-hashtb nil
+(defvar gnus-registry-dirty t
+ "Boolean set to t when the registry is modified")
+
+(defgroup gnus-registry nil
+  "The Gnus registry."
+  :version "22.1"
+  :group 'gnus)
+
+(defvar gnus-registry-hashtb (make-hash-table 			    
+			      :size 256
+			      :test 'equal)
   "*The article registry by Message ID.")
-(setq gnus-registry-hashtb (make-hash-table 
-			    :size 4096
-			    :test 'equal)) ; we test message ID strings equality
 
-;; sample data-header
-;; (defvar tzz-header '(49 "Re[2]: good news" "\"Jonathan Pryor\" <offerlm@aol.com>" "Mon, 17 Feb 2003 10:41:46 +-0800" "<88288020@dytqq>" "" 896 18 "lockgroove.bwh.harvard.edu spam.asian:49" nil))
+(defcustom gnus-registry-unfollowed-groups '("delayed" "drafts" "queue")
+  "List of groups that gnus-registry-split-fancy-with-parent won't follow.
+The group names are matched, they don't have to be fully qualified."
+  :group 'gnus-registry
+  :type '(repeat string))
+
+(defcustom gnus-registry-install nil
+  "Whether the registry should be installed."
+  :group 'gnus-registry
+  :type 'boolean)
+
+(defcustom gnus-registry-clean-empty t
+  "Whether the empty registry entries should be deleted.
+Registry entries are considered empty when they have no groups
+and no extra data."
+  :group 'gnus-registry
+  :type 'boolean)
+
+(defcustom gnus-registry-use-long-group-names nil
+  "Whether the registry should use long group names (BUGGY)."
+  :group 'gnus-registry
+  :type 'boolean)
+
+(defcustom gnus-registry-track-extra nil
+  "Whether the registry should track extra data about a message.
+The Subject and Sender (From:) headers are currently tracked this
+way."
+  :group 'gnus-registry
+  :type
+  '(set :tag "Tracking choices"
+    (const :tag "Track by subject (Subject: header)" subject)
+    (const :tag "Track by sender (From: header)"  sender)))
+
+(defcustom gnus-registry-entry-caching t
+  "Whether the registry should cache extra information."
+  :group 'gnus-registry
+  :type 'boolean)
+
+(defcustom gnus-registry-minimum-subject-length 5
+  "The minimum length of a subject before it's considered trackable."
+  :group 'gnus-registry
+  :type 'integer)
+
+(defcustom gnus-registry-trim-articles-without-groups t
+  "Whether the registry should clean out message IDs without groups."
+  :group 'gnus-registry
+  :type 'boolean)
+
+(defcustom gnus-registry-cache-file 
+  (nnheader-concat 
+   (or gnus-dribble-directory gnus-home-directory "~/") 
+   ".gnus.registry.eld")
+  "File where the Gnus registry will be stored."
+  :group 'gnus-registry
+  :type 'file)
 
-;; (maphash (lambda (key value) (message "key: %s value: %s" key value)) gnus-registry-hashtb)
-;; (clrhash gnus-registry-hashtb)
+(defcustom gnus-registry-max-entries nil
+  "Maximum number of entries in the registry, nil for unlimited."
+  :group 'gnus-registry
+  :type '(radio (const :format "Unlimited " nil)
+		(integer :format "Maximum number: %v")))
 
-;; Function(s) missing in Emacs 20
-(when (memq nil (mapcar 'fboundp '(puthash)))
-  (require 'cl)
-  (unless (fboundp 'puthash)
-    ;; alias puthash is missing from Emacs 20 cl-extra.el
-    (defalias 'puthash 'cl-puthash)))
+(defun gnus-registry-track-subject-p ()
+  (memq 'subject gnus-registry-track-extra))
 
-(defun gnus-register-action (action data-header from &optional to method)
+(defun gnus-registry-track-sender-p ()
+  (memq 'sender gnus-registry-track-extra))
+
+(defun gnus-registry-cache-read ()
+  "Read the registry cache file."
+  (interactive)
+  (let ((file gnus-registry-cache-file))
+    (when (file-exists-p file)
+      (gnus-message 5 "Reading %s..." file)
+      (gnus-load file)
+      (gnus-message 5 "Reading %s...done" file))))
+
+(defun gnus-registry-cache-save ()
+  "Save the registry cache file."
+  (interactive)
+  (let ((file gnus-registry-cache-file))
+    (save-excursion
+      (set-buffer (gnus-get-buffer-create " *Gnus-registry-cache*"))
+      (make-local-variable 'version-control)
+    (setq version-control gnus-backup-startup-file)
+    (setq buffer-file-name file)
+    (setq default-directory (file-name-directory buffer-file-name))
+    (buffer-disable-undo)
+    (erase-buffer)
+    (gnus-message 5 "Saving %s..." file)
+    (if gnus-save-startup-file-via-temp-buffer
+	(let ((coding-system-for-write gnus-ding-file-coding-system)
+	      (standard-output (current-buffer)))
+	  (gnus-gnus-to-quick-newsrc-format t "gnus registry startup file" 'gnus-registry-alist)
+	  (gnus-registry-cache-whitespace file)
+	  (save-buffer))
+      (let ((coding-system-for-write gnus-ding-file-coding-system)
+	    (version-control gnus-backup-startup-file)
+	    (startup-file file)
+	    (working-dir (file-name-directory file))
+	    working-file
+	    (i -1))
+	;; Generate the name of a non-existent file.
+	(while (progn (setq working-file
+			    (format
+			     (if (and (eq system-type 'ms-dos)
+				      (not (gnus-long-file-names)))
+				 "%s#%d.tm#" ; MSDOS limits files to 8+3
+			       (if (memq system-type '(vax-vms axp-vms))
+				   "%s$tmp$%d"
+				 "%s#tmp#%d"))
+			     working-dir (setq i (1+ i))))
+		      (file-exists-p working-file)))
+
+	(unwind-protect
+	    (progn
+	      (gnus-with-output-to-file working-file
+		(gnus-gnus-to-quick-newsrc-format t "gnus registry startup file" 'gnus-registry-alist))
+
+	      ;; These bindings will mislead the current buffer
+	      ;; into thinking that it is visiting the startup
+	      ;; file.
+	      (let ((buffer-backed-up nil)
+		    (buffer-file-name startup-file)
+		    (file-precious-flag t)
+		    (setmodes (file-modes startup-file)))
+		;; Backup the current version of the startup file.
+		(backup-buffer)
+
+		;; Replace the existing startup file with the temp file.
+		(rename-file working-file startup-file t)
+		(gnus-set-file-modes startup-file setmodes)))
+	  (condition-case nil
+	      (delete-file working-file)
+	    (file-error nil)))))
+
+    (gnus-kill-buffer (current-buffer))
+    (gnus-message 5 "Saving %s...done" file))))
+
+;; Idea from Dan Christensen <jdc@chow.mat.jhu.edu>
+;; Save the gnus-registry file with extra line breaks.
+(defun gnus-registry-cache-whitespace (filename)
+  (gnus-message 7 "Adding whitespace to %s" filename)
+  (save-excursion
+    (goto-char (point-min))
+    (while (re-search-forward "^(\\|(\\\"" nil t)
+      (replace-match "\n\\&" t))
+    (goto-char (point-min))
+    (while (re-search-forward " $" nil t)
+      (replace-match "" t t))))
+
+(defun gnus-registry-save (&optional force)
+  (when (or gnus-registry-dirty force)
+    (let ((caching gnus-registry-entry-caching))
+      ;; turn off entry caching, so mtime doesn't get recorded
+      (setq gnus-registry-entry-caching nil)
+      ;; remove entry caches
+      (maphash
+       (lambda (key value)
+	 (if (hash-table-p value)
+	     (remhash key gnus-registry-hashtb)))
+       gnus-registry-hashtb)
+      ;; remove empty entries
+      (when gnus-registry-clean-empty
+	(gnus-registry-clean-empty-function))
+      ;; now trim the registry appropriately
+      (setq gnus-registry-alist (gnus-registry-trim
+				 (hashtable-to-alist gnus-registry-hashtb)))
+      ;; really save
+      (gnus-registry-cache-save)
+      (setq gnus-registry-entry-caching caching)
+      (setq gnus-registry-dirty nil))))
+
+(defun gnus-registry-clean-empty-function ()
+  "Remove all empty entries from the registry.  Returns count thereof."
+  (let ((count 0))
+    (maphash
+     (lambda (key value)
+       (unless (or
+		(gnus-registry-fetch-group key)
+		;; TODO: look for specific extra data here!
+		;; in this example, we look for 'label
+		(gnus-registry-fetch-extra key 'label)) 
+	 (incf count)
+	 (remhash key gnus-registry-hashtb)))
+     gnus-registry-hashtb)
+    count))
+
+(defun gnus-registry-read ()
+  (gnus-registry-cache-read)
+  (setq gnus-registry-hashtb (alist-to-hashtable gnus-registry-alist))
+  (setq gnus-registry-dirty nil))
+
+(defun gnus-registry-trim (alist)
+  "Trim alist to size, using gnus-registry-max-entries."
+  (if (null gnus-registry-max-entries)
+      alist                             ; just return the alist
+    ;; else, when given max-entries, trim the alist
+    (let* ((timehash (make-hash-table
+		      :size 4096
+		      :test 'equal))
+	   (trim-length (- (length alist) gnus-registry-max-entries))
+	   (trim-length (if (natnump trim-length) trim-length 0)))
+      (maphash
+       (lambda (key value)
+         (puthash key (gnus-registry-fetch-extra key 'mtime) timehash))
+       gnus-registry-hashtb)
+
+      ;; we use the return value of this setq, which is the trimmed alist
+      (setq alist
+	    (nthcdr
+	     trim-length
+	     (sort alist 
+		   (lambda (a b)
+		     (time-less-p 
+		      (cdr (gethash (car a) timehash))
+		      (cdr (gethash (car b) timehash))))))))))
+
+(defun alist-to-hashtable (alist)
+  "Build a hashtable from the values in ALIST."
+  (let ((ht (make-hash-table
+	     :size 4096
+	     :test 'equal)))
+    (mapc
+     (lambda (kv-pair)
+       (puthash (car kv-pair) (cdr kv-pair) ht))
+     alist)
+     ht))
+
+(defun hashtable-to-alist (hash)
+  "Build an alist from the values in HASH."
+  (let ((list nil))
+    (maphash
+     (lambda (key value)
+       (setq list (cons (cons key value) list)))
+     hash)
+    list))
+
+(defun gnus-registry-action (action data-header from &optional to method)
   (let* ((id (mail-header-id data-header))
-	(hash-entry (gethash id gnus-registry-hashtb)))
-    (gnus-message 5 "Registry: article %s %s from %s to %s"
+	 (subject (gnus-registry-simplify-subject
+		   (mail-header-subject data-header)))
+	 (sender (mail-header-from data-header))
+	 (from (gnus-group-guess-full-name-from-command-method from))
+	 (to (if to (gnus-group-guess-full-name-from-command-method to) nil))
+	 (to-name (if to to "the Bit Bucket"))
+	 (old-entry (gethash id gnus-registry-hashtb)))
+    (gnus-message 7 "Registry: article %s %s from %s to %s"
+		  id
+		  (if method "respooling" "going")
+		  from
+		  to)
+
+    ;; All except copy will need a delete
+    (gnus-registry-delete-group id from)
+
+    (when (equal 'copy action)
+      (gnus-registry-add-group id from subject sender)) ; undo the delete
+
+    (gnus-registry-add-group id to subject sender)))
+
+(defun gnus-registry-spool-action (id group &optional subject sender)
+  (let ((group (gnus-group-guess-full-name-from-command-method group)))
+    (when (and (stringp id) (string-match "\r$" id))
+      (setq id (substring id 0 -1)))
+    (gnus-message 7 "Registry: article %s spooled to %s"
+		  id
+		  group)
+    (gnus-registry-add-group id group subject sender)))
+
+;; Function for nn{mail|imap}-split-fancy: look up all references in
+;; the cache and if a match is found, return that group.
+(defun gnus-registry-split-fancy-with-parent ()
+  "Split this message into the same group as its parent.  The parent
+is obtained from the registry.  This function can be used as an entry
+in `nnmail-split-fancy' or `nnimap-split-fancy', for example like
+this: (: gnus-registry-split-fancy-with-parent)
+
+This function tracks ALL backends, unlike
+`nnmail-split-fancy-with-parent' which tracks only nnmail
+messages.
+
+For a message to be split, it looks for the parent message in the
+References or In-Reply-To header and then looks in the registry to
+see which group that message was put in.  This group is returned.
+
+See the Info node `(gnus)Fancy Mail Splitting' for more details."
+  (let* ((refstr (or (message-fetch-field "references") "")) ; guarantee string
+	 (reply-to (message-fetch-field "in-reply-to"))	     ; grab reply-to
+	 ;; now, if reply-to is valid, append it to the References
+	 (refstr (if reply-to 
+		     (concat refstr " " reply-to)
+		   refstr))
+	(nnmail-split-fancy-with-parent-ignore-groups
+	 (if (listp nnmail-split-fancy-with-parent-ignore-groups)
+	     nnmail-split-fancy-with-parent-ignore-groups
+	   (list nnmail-split-fancy-with-parent-ignore-groups)))
+	references res)
+    ;; the references string must be valid and parse to valid references
+    (if (and refstr (gnus-extract-references refstr))
+	(progn
+	  (setq references (nreverse (gnus-extract-references refstr)))
+	  (mapcar (lambda (x)
+		    (setq res (or (gnus-registry-fetch-group x) res))
+		    (when (or (gnus-registry-grep-in-list
+			       res
+			       gnus-registry-unfollowed-groups)
+			      (gnus-registry-grep-in-list
+			       res
+			       nnmail-split-fancy-with-parent-ignore-groups))
+		      (setq res nil)))
+		  references))
+
+      ;; else: there were no references, now try the extra tracking
+      (let ((sender (message-fetch-field "from"))
+	    (subject (gnus-registry-simplify-subject
+		      (message-fetch-field "subject")))
+	    (single-match t))
+	(when (and single-match
+		   (gnus-registry-track-sender-p)
+		   sender)
+	  (maphash
+	   (lambda (key value)
+	     (let ((this-sender (cdr
+				 (gnus-registry-fetch-extra key 'sender))))
+	       (when (and single-match
+			  this-sender
+			  (equal sender this-sender))
+		 ;; too many matches, bail
+		 (unless (equal res (gnus-registry-fetch-group key))
+		   (setq single-match nil))
+		 (setq res (gnus-registry-fetch-group key))
+		 (when (and sender res)
+		   (gnus-message
+		    ;; raise level of messaging if gnus-registry-track-extra
+		    (if gnus-registry-track-extra 7 9)
+		    "%s (extra tracking) traced sender %s to group %s"
+		    "gnus-registry-split-fancy-with-parent"
+		    sender
+		    res)))))
+	   gnus-registry-hashtb))
+	(when (and single-match
+		   (gnus-registry-track-subject-p)
+		   subject
+		   (< gnus-registry-minimum-subject-length (length subject)))
+	  (maphash
+	   (lambda (key value)
+	     (let ((this-subject (cdr
+				  (gnus-registry-fetch-extra key 'subject))))
+	       (when (and single-match
+			  this-subject
+			  (equal subject this-subject))
+		 ;; too many matches, bail
+		 (unless (equal res (gnus-registry-fetch-group key))
+		   (setq single-match nil))
+		 (setq res (gnus-registry-fetch-group key))
+		 (when (and subject res)
+		   (gnus-message
+		    ;; raise level of messaging if gnus-registry-track-extra
+		    (if gnus-registry-track-extra 7 9)
+		    "%s (extra tracking) traced subject %s to group %s"
+		    "gnus-registry-split-fancy-with-parent"
+		    subject
+		    res)))))
+	   gnus-registry-hashtb))
+	(unless single-match
+	  (gnus-message
+	   3
+	   "gnus-registry-split-fancy-with-parent: too many extra matches for %s"
+	   refstr)
+	  (setq res nil))))
+    (when (and refstr res)
+      (gnus-message
+       5
+       "gnus-registry-split-fancy-with-parent traced %s to group %s"
+       refstr res))
+
+    (when (and res gnus-registry-use-long-group-names)
+      (let ((m1 (gnus-find-method-for-group res))
+	    (m2 (or gnus-command-method
+		    (gnus-find-method-for-group gnus-newsgroup-name)))
+	    (short-res (gnus-group-short-name res)))
+      (if (gnus-methods-equal-p m1 m2)
+	  (progn
+	    (gnus-message
+	     9
+	     "gnus-registry-split-fancy-with-parent stripped group %s to %s"
+	     res
+	     short-res)
+	    (setq res short-res))
+	;; else...
+	(gnus-message
+	 7
+	 "gnus-registry-split-fancy-with-parent ignored foreign group %s"
+	 res)
+	(setq res nil))))
+    res))
+
+(defun gnus-registry-register-message-ids ()
+  "Register the Message-ID of every article in the group"
+  (unless (gnus-parameter-registry-ignore gnus-newsgroup-name)
+    (dolist (article gnus-newsgroup-articles)
+      (let ((id (gnus-registry-fetch-message-id-fast article)))
+	(unless (gnus-registry-fetch-group id)
+	  (gnus-message 9 "Registry: Registering article %d with group %s"
+			article gnus-newsgroup-name)
+	  (gnus-registry-add-group
+	   (gnus-registry-fetch-message-id-fast article)
+	   gnus-newsgroup-name
+	   (gnus-registry-fetch-simplified-message-subject-fast article)
+	   (gnus-registry-fetch-sender-fast article)))))))
+
+(defun gnus-registry-fetch-message-id-fast (article)
+  "Fetch the Message-ID quickly, using the internal gnus-data-list function"
+  (if (and (numberp article)
+	   (assoc article (gnus-data-list nil)))
+      (mail-header-id (gnus-data-header (assoc article (gnus-data-list nil))))
+    nil))
+
+(defun gnus-registry-simplify-subject (subject)
+  (if (stringp subject)
+      (gnus-simplify-subject subject)
+    nil))
+
+(defun gnus-registry-fetch-simplified-message-subject-fast (article)
+  "Fetch the Subject quickly, using the internal gnus-data-list function"
+  (if (and (numberp article)
+	   (assoc article (gnus-data-list nil)))
+      (gnus-registry-simplify-subject
+       (mail-header-subject (gnus-data-header
+			     (assoc article (gnus-data-list nil)))))
+    nil))
+
+(defun gnus-registry-fetch-sender-fast (article)
+  "Fetch the Sender quickly, using the internal gnus-data-list function"
+  (if (and (numberp article)
+	   (assoc article (gnus-data-list nil)))
+      (mail-header-from (gnus-data-header
+			 (assoc article (gnus-data-list nil))))
+    nil))
+
+(defun gnus-registry-grep-in-list (word list)
+  (when word
+    (memq nil
+	  (mapcar 'not
+		  (mapcar
+		   (lambda (x)
+		     (string-match x word))
+		   list)))))
+
+(defun gnus-registry-fetch-extra (id &optional entry)
+  "Get the extra data of a message, based on the message ID.
+Returns the first place where the trail finds a nonstring."
+  (let ((entry-cache (gethash entry gnus-registry-hashtb)))
+    (if (and entry
+	     (hash-table-p entry-cache)
+	     (gethash id entry-cache))
+	(gethash id entry-cache)
+      ;; else, if there is no caching possible...
+      (let ((trail (gethash id gnus-registry-hashtb)))
+	(when (listp trail)
+	  (dolist (crumb trail)
+	    (unless (stringp crumb)
+	      (return (gnus-registry-fetch-extra-entry crumb entry id)))))))))
+
+(defun gnus-registry-fetch-extra-entry (alist &optional entry id)
+  "Get the extra data of a message, or a specific entry in it.
+Update the entry cache if needed."
+  (if (and entry id)
+      (let ((entry-cache (gethash entry gnus-registry-hashtb))
+	    entree)
+	(when gnus-registry-entry-caching
+	  ;; create the hash table
+	  (unless (hash-table-p entry-cache)
+	    (setq entry-cache (make-hash-table
+			       :size 4096
+			       :test 'equal))
+	    (puthash entry entry-cache gnus-registry-hashtb))
+
+	  ;; get the entree from the hash table or from the alist
+	  (setq entree (gethash id entry-cache)))
+
+	(unless entree
+	  (setq entree (assq entry alist))
+	  (when gnus-registry-entry-caching
+	    (puthash id entree entry-cache)))
+	entree)
+    alist))
+
+(defun gnus-registry-store-extra (id extra)
+  "Store the extra data of a message, based on the message ID.
+The message must have at least one group name."
+  (when (gnus-registry-group-count id)
+    ;; we now know the trail has at least 1 group name, so it's not empty
+    (let ((trail (gethash id gnus-registry-hashtb))
+	  (old-extra (gnus-registry-fetch-extra id))
+	  entry-cache)
+      (dolist (crumb trail)
+	(unless (stringp crumb)
+	  (dolist (entry crumb)
+	    (setq entry-cache (gethash (car entry) gnus-registry-hashtb))
+	  (when entry-cache
+	    (remhash id entry-cache))))
+      (puthash id (cons extra (delete old-extra trail))
+	       gnus-registry-hashtb)
+      (setq gnus-registry-dirty t)))))
+
+(defun gnus-registry-store-extra-entry (id key value)
+  "Put a specific entry in the extras field of the registry entry for id."
+  (let* ((extra (gnus-registry-fetch-extra id))
+	 (alist (cons (cons key value)
+		 (gnus-assq-delete-all key (gnus-registry-fetch-extra id)))))
+    (gnus-registry-store-extra id alist)))
+
+(defun gnus-registry-fetch-group (id)
+  "Get the group of a message, based on the message ID.
+Returns the first place where the trail finds a group name."
+  (when (gnus-registry-group-count id)
+    ;; we now know the trail has at least 1 group name
+    (let ((trail (gethash id gnus-registry-hashtb)))
+      (dolist (crumb trail)
+	(when (stringp crumb)
+	  (return (if gnus-registry-use-long-group-names
+		       crumb
+		     (gnus-group-short-name crumb))))))))
+
+(defun gnus-registry-group-count (id)
+  "Get the number of groups of a message, based on the message ID."
+  (let ((trail (gethash id gnus-registry-hashtb)))
+    (if (and trail (listp trail))
+	(apply '+ (mapcar (lambda (x) (if (stringp x) 1 0)) trail))
+      0)))
+
+(defun gnus-registry-delete-group (id group)
+  "Delete a group for a message, based on the message ID."
+  (when group
+    (when id
+      (let ((trail (gethash id gnus-registry-hashtb))
+	    (group (gnus-group-short-name group)))
+	(puthash id (if trail
+			(delete group trail)
+		      nil)
+		 gnus-registry-hashtb))
+      ;; now, clear the entry if there are no more groups
+      (when gnus-registry-trim-articles-without-groups
+	(unless (gnus-registry-group-count id)
+	  (gnus-registry-delete-id id)))
+      ;; is this ID still in the registry?
+      (when (gethash id gnus-registry-hashtb)
+	(gnus-registry-store-extra-entry id 'mtime (current-time))))))
+
+(defun gnus-registry-delete-id (id)
+  "Delete a message ID from the registry."
+  (when (stringp id)
+    (remhash id gnus-registry-hashtb)
+    (maphash
+     (lambda (key value)
+       (when (hash-table-p value)
+	 (remhash id value)))
+     gnus-registry-hashtb)))
+
+(defun gnus-registry-add-group (id group &optional subject sender)
+  "Add a group for a message, based on the message ID."
+  (when group
+    (when (and id
+	       (not (string-match "totally-fudged-out-message-id" id)))
+      (let ((full-group group)
+	    (group (if gnus-registry-use-long-group-names
+		       group
+		     (gnus-group-short-name group))))
+	(gnus-registry-delete-group id group)
+
+	(unless gnus-registry-use-long-group-names ;; unnecessary in this case
+	  (gnus-registry-delete-group id full-group))
+
+	(let ((trail (gethash id gnus-registry-hashtb)))
+	  (puthash id (if trail
+			  (cons group trail)
+			(list group))
+		   gnus-registry-hashtb)
+
+	  (when (and (gnus-registry-track-subject-p)
+		     subject)
+	    (gnus-registry-store-extra-entry
+	     id
+	     'subject
+	     (gnus-registry-simplify-subject subject)))
+	  (when (and (gnus-registry-track-sender-p)
+		     sender)
+	    (gnus-registry-store-extra-entry
 	     id
-	     (if method "respooling" "going")
-	     (gnus-group-guess-full-name from)
-	     (if to (gnus-group-guess-full-name to) "the Bit Bucket"))
-    (unless hash-entry 
-      (setq hash-entry (puthash id (list data-header) gnus-registry-hashtb)))
-    (puthash id (cons (list action from to method) 
-		      (gethash id gnus-registry-hashtb)) gnus-registry-hashtb)))
-
-(defun gnus-register-spool-action (id group)
-  (gnus-message 5 "Registry: article %s spooled to %s"
-	   id
-	   (gnus-group-prefixed-name 
-	    group 
-	    gnus-internal-registry-spool-current-method 
-	    t)))
-
-(add-hook 'gnus-summary-article-move-hook 'gnus-register-action) ; also does copy, respool, and crosspost
-(add-hook 'gnus-summary-article-delete-hook 'gnus-register-action)
-(add-hook 'gnus-summary-article-expire-hook 'gnus-register-action)
-(add-hook 'nnmail-spool-hook 'gnus-register-spool-action)
+	     'sender
+	     sender))
+
+	  (gnus-registry-store-extra-entry id 'mtime (current-time)))))))
+
+(defun gnus-registry-clear ()
+  "Clear the Gnus registry."
+  (interactive)
+  (setq gnus-registry-alist nil)
+  (setq gnus-registry-hashtb (alist-to-hashtable gnus-registry-alist))
+  (setq gnus-registry-dirty t))
+
+;;;###autoload
+(defun gnus-registry-initialize ()
+  (interactive)
+  (setq gnus-registry-install t)
+  (gnus-registry-install-hooks)
+  (gnus-registry-read))
+
+;;;###autoload
+(defun gnus-registry-install-hooks ()
+  "Install the registry hooks."
+  (interactive)
+  (add-hook 'gnus-summary-article-move-hook 'gnus-registry-action)
+  (add-hook 'gnus-summary-article-delete-hook 'gnus-registry-action)
+  (add-hook 'gnus-summary-article-expire-hook 'gnus-registry-action)
+  (add-hook 'nnmail-spool-hook 'gnus-registry-spool-action)
+
+  (add-hook 'gnus-save-newsrc-hook 'gnus-registry-save)
+  (add-hook 'gnus-read-newsrc-el-hook 'gnus-registry-read)
+
+  (add-hook 'gnus-summary-prepare-hook 'gnus-registry-register-message-ids))
+
+(defun gnus-registry-unload-hook ()
+  "Uninstall the registry hooks."
+  (interactive)
+  (remove-hook 'gnus-summary-article-move-hook 'gnus-registry-action)
+  (remove-hook 'gnus-summary-article-delete-hook 'gnus-registry-action)
+  (remove-hook 'gnus-summary-article-expire-hook 'gnus-registry-action)
+  (remove-hook 'nnmail-spool-hook 'gnus-registry-spool-action)
+
+  (remove-hook 'gnus-save-newsrc-hook 'gnus-registry-save)
+  (remove-hook 'gnus-read-newsrc-el-hook 'gnus-registry-read)
+
+  (remove-hook 'gnus-summary-prepare-hook 'gnus-registry-register-message-ids))
+
+(add-hook 'gnus-registry-unload-hook 'gnus-registry-unload-hook)
+
+(when gnus-registry-install
+  (gnus-registry-install-hooks)
+  (gnus-registry-read))
 
 ;; TODO: a lot of things
-;; TODO: we have to load and save the registry through gnus-save-newsrc-file
 
 (provide 'gnus-registry)
 
+;;; arch-tag: 5cba0a32-718a-4a97-8c91-0a15af21da94
 ;;; gnus-registry.el ends here