lisp/gnus-cache.el

   1 ;;; gnus-cache.el --- cache interface for Gnus
   2 ;; Copyright (C) 1995,96 Free Software Foundation, Inc.
   3
   4 ;; Author: Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
   5 ;; Keywords: news
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;;; Code:
  27
  28 (require 'gnus)
  29 (eval-when-compile (require 'cl))
  30
  31 (defvar gnus-cache-directory
  32   (nnheader-concat gnus-directory "cache/")
  33   "*The directory where cached articles will be stored.")
  34
  35 (defvar gnus-cache-active-file
  36   (concat (file-name-as-directory gnus-cache-directory) "active")
  37   "*The cache active file.")
  38
  39 (defvar gnus-cache-enter-articles '(ticked dormant)
  40   "*Classes of articles to enter into the cache.")
  41
  42 (defvar gnus-cache-remove-articles '(read)
  43   "*Classes of articles to remove from the cache.")
  44
  45 (defvar gnus-uncacheable-groups nil
  46   "*Groups that match this regexp will not be cached.
  47
  48 If you want to avoid caching your nnml groups, you could set this
  49 variable to \"^nnml\".")
  50
  51 \f
  52
  53 ;;; Internal variables.
  54
  55 (defvar gnus-cache-buffer nil)
  56 (defvar gnus-cache-active-hashtb nil)
  57 (defvar gnus-cache-active-altered nil)
  58
  59 (eval-and-compile
  60   (autoload 'nnml-generate-nov-databases-1 "nnml")
  61   (autoload 'nnvirtual-find-group-art "nnvirtual"))
  62
  63 \f
  64
  65 ;;; Functions called from Gnus.
  66
  67 (defun gnus-cache-open ()
  68   "Initialize the cache."
  69   (when (or (file-exists-p gnus-cache-directory)
  70             (and gnus-use-cache
  71                  (not (eq gnus-use-cache 'passive))))
  72     (gnus-cache-read-active)))
  73
  74 (condition-case ()
  75     (gnus-add-shutdown 'gnus-cache-close 'gnus)
  76   ;; Complexities of byte-compiling makes this kludge necessary.  Eeek.
  77   (error nil))
  78
  79 (defun gnus-cache-close ()
  80   "Shut down the cache."
  81   (gnus-cache-write-active)
  82   (gnus-cache-save-buffers)
  83   (setq gnus-cache-active-hashtb nil))
  84
  85 (defun gnus-cache-save-buffers ()
  86   ;; save the overview buffer if it exists and has been modified
  87   ;; delete empty cache subdirectories
  88   (if (null gnus-cache-buffer)
  89       ()
  90     (let ((buffer (cdr gnus-cache-buffer))
  91           (overview-file (gnus-cache-file-name
  92                           (car gnus-cache-buffer) ".overview")))
  93       ;; write the overview only if it was modified
  94       (if (buffer-modified-p buffer)
  95           (save-excursion
  96             (set-buffer buffer)
  97             (if (> (buffer-size) 0)
  98                 ;; non-empty overview, write it out
  99                 (progn
 100                   (gnus-make-directory (file-name-directory overview-file))
 101                   (write-region (point-min) (point-max)
 102                                 overview-file nil 'quietly))
 103               ;; empty overview file, remove it
 104               (and (file-exists-p overview-file)
 105                    (delete-file overview-file))
 106               ;; if possible, remove group's cache subdirectory
 107               (condition-case nil
 108                   ;; FIXME: we can detect the error type and warn the user
 109                   ;; of any inconsistencies (articles w/o nov entries?).
 110                   ;; for now, just be conservative...delete only if safe -- sj
 111                   (delete-directory (file-name-directory overview-file))
 112                 (error nil)))))
 113       ;; kill the buffer, it's either unmodified or saved
 114       (gnus-kill-buffer buffer)
 115       (setq gnus-cache-buffer nil))))
 116
 117 (defun gnus-cache-possibly-enter-article
 118   (group article headers ticked dormant unread &optional force)
 119   (when (and (or force (not (eq gnus-use-cache 'passive)))
 120              (numberp article)
 121              (> article 0)
 122              (vectorp headers)) ; This might be a dummy article.
 123     ;; If this is a virtual group, we find the real group.
 124     (when (gnus-virtual-group-p group)
 125       (let ((result (nnvirtual-find-group-art
 126                      (gnus-group-real-name group) article)))
 127         (setq group (car result)
 128               headers (copy-sequence headers))
 129         (mail-header-set-number headers (cdr result))))
 130     (let ((number (mail-header-number headers))
 131           file dir)
 132       (when (and (> number 0)           ; Reffed article.
 133                  (or (not gnus-uncacheable-groups)
 134                      (not (string-match gnus-uncacheable-groups group)))
 135                  (or force
 136                      (gnus-cache-member-of-class
 137                       gnus-cache-enter-articles ticked dormant unread))
 138                  (not (file-exists-p (setq file (gnus-cache-file-name
 139                                                  group number)))))
 140         ;; Possibly create the cache directory.
 141         (or (file-exists-p (setq dir (file-name-directory file)))
 142             (gnus-make-directory dir))
 143         ;; Save the article in the cache.
 144         (if (file-exists-p file)
 145             t                           ; The article already is saved.
 146           (save-excursion
 147             (set-buffer nntp-server-buffer)
 148             (let ((gnus-use-cache nil))
 149               (gnus-request-article-this-buffer number group))
 150             (when (> (buffer-size) 0)
 151               (write-region (point-min) (point-max) file nil 'quiet)
 152               (gnus-cache-change-buffer group)
 153               (set-buffer (cdr gnus-cache-buffer))
 154               (goto-char (point-max))
 155               (forward-line -1)
 156               (while (condition-case ()
 157                          (and (not (bobp))
 158                               (> (read (current-buffer)) number))
 159                        (error
 160                         ;; The line was malformed, so we just remove it!!
 161                         (gnus-delete-line)
 162                         t))
 163                 (forward-line -1))
 164               (if (bobp)
 165                   (if (not (eobp))
 166                       (progn
 167                         (beginning-of-line)
 168                         (if (< (read (current-buffer)) number)
 169                             (forward-line 1)))
 170                     (beginning-of-line))
 171                 (forward-line 1))
 172               (beginning-of-line)
 173               ;; [number subject from date id references chars lines xref]
 174               (insert (format "%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\t\n"
 175                               (mail-header-number headers)
 176                               (mail-header-subject headers)
 177                               (mail-header-from headers)
 178                               (mail-header-date headers)
 179                               (mail-header-id headers)
 180                               (or (mail-header-references headers) "")
 181                               (or (mail-header-chars headers) "")
 182                               (or (mail-header-lines headers) "")
 183                               (or (mail-header-xref headers) "")))
 184               ;; Update the active info.
 185               (set-buffer gnus-summary-buffer)
 186               (gnus-cache-update-active group number)
 187               (push article gnus-newsgroup-cached)
 188               (gnus-summary-update-secondary-mark article))
 189             t))))))
 190
 191 (defun gnus-cache-enter-remove-article (article)
 192   "Mark ARTICLE for later possible removal."
 193   (when article
 194     (push article gnus-cache-removable-articles)))
 195
 196 (defun gnus-cache-possibly-remove-articles ()
 197   "Possibly remove some of the removable articles."
 198   (if (not (gnus-virtual-group-p gnus-newsgroup-name))
 199       (gnus-cache-possibly-remove-articles-1)
 200     (let ((arts gnus-cache-removable-articles)
 201           ga)
 202       (while arts
 203         (when (setq ga (nnvirtual-find-group-art
 204                         (gnus-group-real-name gnus-newsgroup-name) (pop arts)))
 205           (let ((gnus-cache-removable-articles (list (cdr ga)))
 206                 (gnus-newsgroup-name (car ga)))
 207             (gnus-cache-possibly-remove-articles-1)))))
 208     (setq gnus-cache-removable-articles nil)))
 209
 210 (defun gnus-cache-possibly-remove-articles-1 ()
 211   "Possibly remove some of the removable articles."
 212   (unless (eq gnus-use-cache 'passive)
 213     (let ((articles gnus-cache-removable-articles)
 214           (cache-articles gnus-newsgroup-cached)
 215           article)
 216       (gnus-cache-change-buffer gnus-newsgroup-name)
 217       (while articles
 218         (if (memq (setq article (pop articles)) cache-articles)
 219             ;; The article was in the cache, so we see whether we are
 220             ;; supposed to remove it from the cache.
 221             (gnus-cache-possibly-remove-article
 222              article (memq article gnus-newsgroup-marked)
 223              (memq article gnus-newsgroup-dormant)
 224              (or (memq article gnus-newsgroup-unreads)
 225                  (memq article gnus-newsgroup-unselected))))))
 226     ;; The overview file might have been modified, save it
 227     ;; safe because we're only called at group exit anyway.
 228     (gnus-cache-save-buffers)))
 229
 230 (defun gnus-cache-request-article (article group)
 231   "Retrieve ARTICLE in GROUP from the cache."
 232   (let ((file (gnus-cache-file-name group article))
 233         (buffer-read-only nil))
 234     (when (file-exists-p file)
 235       (erase-buffer)
 236       (gnus-kill-all-overlays)
 237       (insert-file-contents file)
 238       t)))
 239
 240 (defun gnus-cache-possibly-alter-active (group active)
 241   "Alter the ACTIVE info for GROUP to reflect the articles in the cache."
 242   (when gnus-cache-active-hashtb
 243     (let ((cache-active (gnus-gethash group gnus-cache-active-hashtb)))
 244       (and cache-active
 245            (< (car cache-active) (car active))
 246            (setcar active (car cache-active)))
 247       (and cache-active
 248            (> (cdr cache-active) (cdr active))
 249            (setcdr active (cdr cache-active))))))
 250
 251 (defun gnus-cache-retrieve-headers (articles group &optional fetch-old)
 252   "Retrieve the headers for ARTICLES in GROUP."
 253   (let ((cached
 254          (setq gnus-newsgroup-cached (gnus-cache-articles-in-group group))))
 255     (if (not cached)
 256         ;; No cached articles here, so we just retrieve them
 257         ;; the normal way.
 258         (let ((gnus-use-cache nil))
 259           (gnus-retrieve-headers articles group fetch-old))
 260       (let ((uncached-articles (gnus-sorted-intersection
 261                                 (gnus-sorted-complement articles cached)
 262                                 articles))
 263             (cache-file (gnus-cache-file-name group ".overview"))
 264             type)
 265         ;; We first retrieve all the headers that we don't have in
 266         ;; the cache.
 267         (let ((gnus-use-cache nil))
 268           (when uncached-articles
 269             (setq type (and articles
 270                             (gnus-retrieve-headers
 271                              uncached-articles group fetch-old)))))
 272         (gnus-cache-save-buffers)
 273         ;; Then we insert the cached headers.
 274         (save-excursion
 275           (cond
 276            ((not (file-exists-p cache-file))
 277             ;; There are no cached headers.
 278             type)
 279            ((null type)
 280             ;; There were no uncached headers (or retrieval was
 281             ;; unsuccessful), so we use the cached headers exclusively.
 282             (set-buffer nntp-server-buffer)
 283             (erase-buffer)
 284             (insert-file-contents cache-file)
 285             'nov)
 286            ((eq type 'nov)
 287             ;; We have both cached and uncached NOV headers, so we
 288             ;; braid them.
 289             (gnus-cache-braid-nov group cached)
 290             type)
 291            (t
 292             ;; We braid HEADs.
 293             (gnus-cache-braid-heads group (gnus-sorted-intersection
 294                                            cached articles))
 295             type)))))))
 296
 297 (defun gnus-cache-enter-article (&optional n)
 298   "Enter the next N articles into the cache.
 299 If not given a prefix, use the process marked articles instead.
 300 Returns the list of articles entered."
 301   (interactive "P")
 302   (gnus-set-global-variables)
 303   (let ((articles (gnus-summary-work-articles n))
 304         article out)
 305     (while articles
 306       (setq article (pop articles))
 307       (when (gnus-cache-possibly-enter-article
 308              gnus-newsgroup-name article (gnus-summary-article-header article)
 309              nil nil nil t)
 310         (push article out))
 311       (gnus-summary-remove-process-mark article)
 312       (gnus-summary-update-secondary-mark article))
 313     (gnus-summary-next-subject 1)
 314     (gnus-summary-position-point)
 315     (nreverse out)))
 316
 317 (defun gnus-cache-remove-article (n)
 318   "Remove the next N articles from the cache.
 319 If not given a prefix, use the process marked articles instead.
 320 Returns the list of articles removed."
 321   (interactive "P")
 322   (gnus-set-global-variables)
 323   (gnus-cache-change-buffer gnus-newsgroup-name)
 324   (let ((articles (gnus-summary-work-articles n))
 325         article out)
 326     (while articles
 327       (setq article (pop articles))
 328       (when (gnus-cache-possibly-remove-article article nil nil nil t)
 329         (push article out))
 330       (gnus-summary-remove-process-mark article)
 331       (gnus-summary-update-secondary-mark article))
 332     (gnus-summary-next-subject 1)
 333     (gnus-summary-position-point)
 334     (nreverse out)))
 335
 336 (defun gnus-cached-article-p (article)
 337   "Say whether ARTICLE is cached in the current group."
 338   (memq article gnus-newsgroup-cached))
 339
 340 ;;; Internal functions.
 341
 342 (defun gnus-cache-change-buffer (group)
 343   (and gnus-cache-buffer
 344        ;; See if the current group's overview cache has been loaded.
 345        (or (string= group (car gnus-cache-buffer))
 346            ;; Another overview cache is current, save it.
 347            (gnus-cache-save-buffers)))
 348   ;; if gnus-cache buffer is nil, create it
 349   (or gnus-cache-buffer
 350       ;; Create cache buffer
 351       (save-excursion
 352         (setq gnus-cache-buffer
 353               (cons group
 354                     (set-buffer (get-buffer-create " *gnus-cache-overview*"))))
 355         (buffer-disable-undo (current-buffer))
 356         ;; Insert the contents of this group's cache overview.
 357         (erase-buffer)
 358         (let ((file (gnus-cache-file-name group ".overview")))
 359           (and (file-exists-p file)
 360                (insert-file-contents file)))
 361         ;; We have a fresh (empty/just loaded) buffer,
 362         ;; mark it as unmodified to save a redundant write later.
 363         (set-buffer-modified-p nil))))
 364
 365 ;; Return whether an article is a member of a class.
 366 (defun gnus-cache-member-of-class (class ticked dormant unread)
 367   (or (and ticked (memq 'ticked class))
 368       (and dormant (memq 'dormant class))
 369       (and unread (memq 'unread class))
 370       (and (not unread) (not ticked) (not dormant) (memq 'read class))))
 371
 372 (defun gnus-cache-file-name (group article)
 373   (concat (file-name-as-directory gnus-cache-directory)
 374           (file-name-as-directory
 375            (if (gnus-use-long-file-name 'not-cache)
 376                group
 377              (let ((group (concat group "")))
 378                (if (string-match ":" group)
 379                    (aset group (match-beginning 0) ?/))
 380                (nnheader-replace-chars-in-string group ?. ?/))))
 381           (if (stringp article) article (int-to-string article))))
 382
 383 (defun gnus-cache-update-article (group article)
 384   "If ARTICLE is in the cache, remove it and re-enter it."
 385   (when (gnus-cache-possibly-remove-article article nil nil nil t)
 386     (let ((gnus-use-cache nil))
 387       (gnus-cache-possibly-enter-article
 388        gnus-newsgroup-name article (gnus-summary-article-header article)
 389        nil nil nil t))))
 390
 391 (defun gnus-cache-possibly-remove-article (article ticked dormant unread
 392                                                    &optional force)
 393   "Possibly remove ARTICLE from the cache."
 394   (let ((group gnus-newsgroup-name)
 395         (number article)
 396         file)
 397     ;; If this is a virtual group, we find the real group.
 398     (when (gnus-virtual-group-p group)
 399       (let ((result (nnvirtual-find-group-art
 400                      (gnus-group-real-name group) article)))
 401         (setq group (car result)
 402               number (cdr result))))
 403     (setq file (gnus-cache-file-name group number))
 404     (when (and (file-exists-p file)
 405                (or force
 406                    (gnus-cache-member-of-class
 407                     gnus-cache-remove-articles ticked dormant unread)))
 408       (save-excursion
 409         (delete-file file)
 410         (set-buffer (cdr gnus-cache-buffer))
 411         (goto-char (point-min))
 412         (if (or (looking-at (concat (int-to-string number) "\t"))
 413                 (search-forward (concat "\n" (int-to-string number) "\t")
 414                                 (point-max) t))
 415             (delete-region (progn (beginning-of-line) (point))
 416                            (progn (forward-line 1) (point)))))
 417       (setq gnus-newsgroup-cached
 418             (delq article gnus-newsgroup-cached))
 419       (gnus-summary-update-secondary-mark article)
 420       t)))
 421
 422 (defun gnus-cache-articles-in-group (group)
 423   "Return a sorted list of cached articles in GROUP."
 424   (let ((dir (file-name-directory (gnus-cache-file-name group 1)))
 425         articles)
 426     (when (file-exists-p dir)
 427       (sort (mapcar (lambda (name) (string-to-int name))
 428                     (directory-files dir nil "^[0-9]+$" t))
 429             '<))))
 430
 431 (defun gnus-cache-braid-nov (group cached)
 432   (let ((cache-buf (get-buffer-create " *gnus-cache*"))
 433         beg end)
 434     (gnus-cache-save-buffers)
 435     (save-excursion
 436       (set-buffer cache-buf)
 437       (buffer-disable-undo (current-buffer))
 438       (erase-buffer)
 439       (insert-file-contents (gnus-cache-file-name group ".overview"))
 440       (goto-char (point-min))
 441       (insert "\n")
 442       (goto-char (point-min)))
 443     (set-buffer nntp-server-buffer)
 444     (goto-char (point-min))
 445     (while cached
 446       (while (and (not (eobp))
 447                   (< (read (current-buffer)) (car cached)))
 448         (forward-line 1))
 449       (beginning-of-line)
 450       (save-excursion
 451         (set-buffer cache-buf)
 452         (if (search-forward (concat "\n" (int-to-string (car cached)) "\t")
 453                             nil t)
 454             (setq beg (progn (beginning-of-line) (point))
 455                   end (progn (end-of-line) (point)))
 456           (setq beg nil)))
 457       (if beg (progn (insert-buffer-substring cache-buf beg end)
 458                      (insert "\n")))
 459       (setq cached (cdr cached)))
 460     (kill-buffer cache-buf)))
 461
 462 (defun gnus-cache-braid-heads (group cached)
 463   (let ((cache-buf (get-buffer-create " *gnus-cache*")))
 464     (save-excursion
 465       (set-buffer cache-buf)
 466       (buffer-disable-undo (current-buffer))
 467       (erase-buffer))
 468     (set-buffer nntp-server-buffer)
 469     (goto-char (point-min))
 470     (while cached
 471       (while (and (not (eobp))
 472                   (looking-at "2.. +\\([0-9]+\\) ")
 473                   (< (progn (goto-char (match-beginning 1))
 474                             (read (current-buffer)))
 475                      (car cached)))
 476         (search-forward "\n.\n" nil 'move))
 477       (beginning-of-line)
 478       (save-excursion
 479         (set-buffer cache-buf)
 480         (erase-buffer)
 481         (insert-file-contents (gnus-cache-file-name group (car cached)))
 482         (goto-char (point-min))
 483         (insert "220 ")
 484         (princ (car cached) (current-buffer))
 485         (insert " Article retrieved.\n")
 486         (search-forward "\n\n" nil 'move)
 487         (delete-region (point) (point-max))
 488         (forward-char -1)
 489         (insert "."))
 490       (insert-buffer-substring cache-buf)
 491       (setq cached (cdr cached)))
 492     (kill-buffer cache-buf)))
 493
 494 ;;;###autoload
 495 (defun gnus-jog-cache ()
 496   "Go through all groups and put the articles into the cache."
 497   (interactive)
 498   (let ((gnus-mark-article-hook nil)
 499         (gnus-expert-user t)
 500         (nnmail-spool-file nil)
 501         (gnus-use-dribble-file nil)
 502         (gnus-novice-user nil)
 503         (gnus-large-newsgroup nil))
 504     ;; Start Gnus.
 505     (gnus)
 506     ;; Go through all groups...
 507     (gnus-group-mark-buffer)
 508     (gnus-group-universal-argument
 509      nil nil
 510      (lambda ()
 511        (gnus-summary-read-group nil nil t)
 512        ;; ... and enter the articles into the cache.
 513        (when (eq major-mode 'gnus-summary-mode)
 514          (gnus-uu-mark-buffer)
 515          (gnus-cache-enter-article)
 516          (kill-buffer (current-buffer)))))))
 517
 518 (defun gnus-cache-read-active (&optional force)
 519   "Read the cache active file."
 520   (unless (file-exists-p gnus-cache-directory)
 521     (make-directory gnus-cache-directory t))
 522   (if (not (and (file-exists-p gnus-cache-active-file)
 523                 (or force (not gnus-cache-active-hashtb))))
 524       ;; There is no active file, so we generate one.
 525       (gnus-cache-generate-active)
 526     ;; We simply read the active file.
 527     (save-excursion
 528       (gnus-set-work-buffer)
 529       (insert-file-contents gnus-cache-active-file)
 530       (gnus-active-to-gnus-format
 531        nil (setq gnus-cache-active-hashtb
 532                  (gnus-make-hashtable
 533                   (count-lines (point-min) (point-max)))))
 534       (setq gnus-cache-active-altered nil))))
 535
 536 (defun gnus-cache-write-active (&optional force)
 537   "Write the active hashtb to the active file."
 538   (when (or force
 539             (and gnus-cache-active-hashtb
 540                  gnus-cache-active-altered))
 541     (save-excursion
 542       (gnus-set-work-buffer)
 543       (mapatoms
 544        (lambda (sym)
 545          (when (and sym (boundp sym))
 546            (insert (format "%s %d %d y\n"
 547                            (symbol-name sym) (cdr (symbol-value sym))
 548                            (car (symbol-value sym))))))
 549        gnus-cache-active-hashtb)
 550       (gnus-make-directory (file-name-directory gnus-cache-active-file))
 551       (write-region
 552        (point-min) (point-max) gnus-cache-active-file nil 'silent))
 553     ;; Mark the active hashtb as unaltered.
 554     (setq gnus-cache-active-altered nil)))
 555
 556 (defun gnus-cache-update-active (group number &optional low)
 557   "Update the upper bound of the active info of GROUP to NUMBER.
 558 If LOW, update the lower bound instead."
 559   (let ((active (gnus-gethash group gnus-cache-active-hashtb)))
 560     (if (null active)
 561         ;; We just create a new active entry for this group.
 562         (gnus-sethash group (cons number number) gnus-cache-active-hashtb)
 563       ;; Update the lower or upper bound.
 564       (if low
 565           (setcar active number)
 566         (setcdr active number))
 567       ;; Mark the active hashtb as altered.
 568       (setq gnus-cache-active-altered t))))
 569
 570 ;;;###autoload
 571 (defun gnus-cache-generate-active (&optional directory)
 572   "Generate the cache active file."
 573   (interactive)
 574   (let* ((top (null directory))
 575          (directory (expand-file-name (or directory gnus-cache-directory)))
 576          (files (directory-files directory 'full))
 577          (group
 578           (if top
 579               ""
 580             (string-match
 581              (concat "^" (file-name-as-directory
 582                           (expand-file-name gnus-cache-directory)))
 583              (directory-file-name directory))
 584             (nnheader-replace-chars-in-string
 585              (substring (directory-file-name directory) (match-end 0))
 586              ?/ ?.)))
 587          nums alphs)
 588     (when top
 589       (gnus-message 5 "Generating the cache active file...")
 590       (setq gnus-cache-active-hashtb (gnus-make-hashtable 123)))
 591     ;; Separate articles from all other files and directories.
 592     (while files
 593       (if (string-match "^[0-9]+$" (file-name-nondirectory (car files)))
 594           (push (string-to-int (file-name-nondirectory (pop files))) nums)
 595         (push (pop files) alphs)))
 596     ;; If we have nums, then this is probably a valid group.
 597     (when (setq nums (sort nums '<))
 598       (gnus-sethash group (cons (car nums) (gnus-last-element nums))
 599                     gnus-cache-active-hashtb))
 600     ;; Go through all the other files.
 601     (while alphs
 602       (when (and (file-directory-p (car alphs))
 603                  (not (string-match "^\\.\\.?$"
 604                                     (file-name-nondirectory (car alphs)))))
 605         ;; We descend directories.
 606         (gnus-cache-generate-active (car alphs)))
 607       (setq alphs (cdr alphs)))
 608     ;; Write the new active file.
 609     (when top
 610       (gnus-cache-write-active t)
 611       (gnus-message 5 "Generating the cache active file...done"))))
 612
 613 ;;;###autoload
 614 (defun gnus-cache-generate-nov-databases (dir)
 615   "Generate NOV files recursively starting in DIR."
 616   (interactive (list gnus-cache-directory))
 617   (gnus-cache-close)
 618   (let ((nnml-generate-active-function 'identity))
 619     (nnml-generate-nov-databases-1 dir)))
 620
 621 (provide 'gnus-cache)
 622
 623 ;;; gnus-cache.el ends here