lisp/gnus/nnweb.el

   1 ;;; nnweb.el --- retrieving articles via web search engines
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   4 ;;   2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
   5
   6 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   7 ;; Keywords: news
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Note: You need to have `w3' installed for some functions to work.
  27
  28 ;;; Code:
  29
  30 (eval-when-compile (require 'cl))
  31
  32 (require 'nnoo)
  33 (require 'message)
  34 (require 'gnus-util)
  35 (require 'gnus)
  36 (require 'nnmail)
  37 (require 'mm-util)
  38 (require 'mm-url)
  39 (eval-and-compile
  40   (ignore-errors
  41     (require 'url)))
  42 (autoload 'w3-parse-buffer "w3-parse")
  43
  44 (nnoo-declare nnweb)
  45
  46 (defvoo nnweb-directory (nnheader-concat gnus-directory "nnweb/")
  47   "Where nnweb will save its files.")
  48
  49 (defvoo nnweb-type 'google
  50   "What search engine type is being used.
  51 Valid types include `google', `dejanews', and `gmane'.")
  52
  53 (defvar nnweb-type-definition
  54   '((google
  55      (id . "http://www.google.com/groups?as_umsgid=%s&hl=en&dmode=source")
  56      (result . "http://groups.google.com/group/%s/msg/%s?dmode=source")
  57      (article . nnweb-google-wash-article)
  58      (reference . identity)
  59      (map . nnweb-google-create-mapping)
  60      (search . nnweb-google-search)
  61      (address . "http://groups.google.com/groups")
  62      (base    . "http://groups.google.com")
  63      (identifier . nnweb-google-identity))
  64     (dejanews ;; alias of google
  65      (id . "http://www.google.com/groups?as_umsgid=%s&hl=en&dmode=source")
  66      (result . "http://groups.google.com/group/%s/msg/%s?dmode=source")
  67      (article . nnweb-google-wash-article)
  68      (reference . identity)
  69      (map . nnweb-google-create-mapping)
  70      (search . nnweb-google-search)
  71      (address . "http://groups.google.com/groups")
  72      (base    . "http://groups.google.com")
  73      (identifier . nnweb-google-identity))
  74     (gmane
  75      (article . nnweb-gmane-wash-article)
  76      (id . "http://gmane.org/view.php?group=%s")
  77      (reference . identity)
  78      (map . nnweb-gmane-create-mapping)
  79      (search . nnweb-gmane-search)
  80      (address . "http://search.gmane.org/nov.php")
  81      (identifier . nnweb-gmane-identity)))
  82   "Type-definition alist.")
  83
  84 (defvoo nnweb-search nil
  85   "Search string to feed to Google.")
  86
  87 (defvoo nnweb-max-hits 999
  88   "Maximum number of hits to display.")
  89
  90 (defvoo nnweb-ephemeral-p nil
  91   "Whether this nnweb server is ephemeral.")
  92
  93 ;;; Internal variables
  94
  95 (defvoo nnweb-articles nil)
  96 (defvoo nnweb-buffer nil)
  97 (defvoo nnweb-group-alist nil)
  98 (defvoo nnweb-group nil)
  99 (defvoo nnweb-hashtb nil)
 100
 101 ;;; Interface functions
 102
 103 (nnoo-define-basics nnweb)
 104
 105 (deffoo nnweb-retrieve-headers (articles &optional group server fetch-old)
 106   (nnweb-possibly-change-server group server)
 107   (save-excursion
 108     (set-buffer nntp-server-buffer)
 109     (erase-buffer)
 110     (let (article header)
 111       (mm-with-unibyte-current-buffer
 112         (while (setq article (pop articles))
 113           (when (setq header (cadr (assq article nnweb-articles)))
 114             (nnheader-insert-nov header))))
 115       'nov)))
 116
 117 (deffoo nnweb-request-scan (&optional group server)
 118   (nnweb-possibly-change-server group server)
 119   (if nnweb-ephemeral-p
 120       (setq nnweb-hashtb (gnus-make-hashtable 4095))
 121     (unless nnweb-articles
 122       (nnweb-read-overview group)))
 123   (funcall (nnweb-definition 'map))
 124   (unless nnweb-ephemeral-p
 125     (nnweb-write-active)
 126     (nnweb-write-overview group)))
 127
 128 (deffoo nnweb-request-group (group &optional server dont-check)
 129   (nnweb-possibly-change-server group server)
 130   (unless (or nnweb-ephemeral-p
 131               dont-check
 132               nnweb-articles)
 133     (nnweb-read-overview group))
 134   (cond
 135    ((not nnweb-articles)
 136     (nnheader-report 'nnweb "No matching articles"))
 137    (t
 138     (let ((active (if nnweb-ephemeral-p
 139                       (cons (caar nnweb-articles)
 140                             (caar (last nnweb-articles)))
 141                     (cadr (assoc group nnweb-group-alist)))))
 142       (nnheader-report 'nnweb "Opened group %s" group)
 143       (nnheader-insert
 144        "211 %d %d %d %s\n" (length nnweb-articles)
 145        (car active) (cdr active) group)))))
 146
 147 (deffoo nnweb-close-group (group &optional server)
 148   (nnweb-possibly-change-server group server)
 149   (when (gnus-buffer-live-p nnweb-buffer)
 150     (save-excursion
 151       (set-buffer nnweb-buffer)
 152       (set-buffer-modified-p nil)
 153       (kill-buffer nnweb-buffer)))
 154   t)
 155
 156 (deffoo nnweb-request-article (article &optional group server buffer)
 157   (nnweb-possibly-change-server group server)
 158   (save-excursion
 159     (set-buffer (or buffer nntp-server-buffer))
 160     (let* ((header (cadr (assq article nnweb-articles)))
 161            (url (and header (mail-header-xref header))))
 162       (when (or (and url
 163                      (mm-with-unibyte-current-buffer
 164                        (mm-url-insert url)))
 165                 (and (stringp article)
 166                      (nnweb-definition 'id t)
 167                      (let ((fetch (nnweb-definition 'id))
 168                            art active)
 169                        (when (string-match "^<\\(.*\\)>$" article)
 170                          (setq art (match-string 1 article)))
 171                        (when (and fetch art)
 172                          (setq url (format fetch
 173                                            (mm-url-form-encode-xwfu art)))
 174                          (mm-with-unibyte-current-buffer
 175                            (mm-url-insert url))
 176                          (if (nnweb-definition 'reference t)
 177                              (setq article
 178                                    (funcall (nnweb-definition
 179                                              'reference) article)))))))
 180         (unless nnheader-callback-function
 181           (funcall (nnweb-definition 'article)))
 182         (nnheader-report 'nnweb "Fetched article %s" article)
 183         (cons group (and (numberp article) article))))))
 184
 185 (deffoo nnweb-close-server (&optional server)
 186   (when (and (nnweb-server-opened server)
 187              (gnus-buffer-live-p nnweb-buffer))
 188     (save-excursion
 189       (set-buffer nnweb-buffer)
 190       (set-buffer-modified-p nil)
 191       (kill-buffer nnweb-buffer)))
 192   (nnoo-close-server 'nnweb server))
 193
 194 (deffoo nnweb-request-list (&optional server)
 195   (nnweb-possibly-change-server nil server)
 196   (save-excursion
 197     (set-buffer nntp-server-buffer)
 198     (nnmail-generate-active (list (assoc server nnweb-group-alist)))
 199     t))
 200
 201 (deffoo nnweb-request-update-info (group info &optional server)
 202   (nnweb-possibly-change-server group server))
 203
 204 (deffoo nnweb-asynchronous-p ()
 205   nil)
 206
 207 (deffoo nnweb-request-create-group (group &optional server args)
 208   (nnweb-possibly-change-server nil server)
 209   (nnweb-request-delete-group group)
 210   (push `(,group ,(cons 1 0)) nnweb-group-alist)
 211   (nnweb-write-active)
 212   t)
 213
 214 (deffoo nnweb-request-delete-group (group &optional force server)
 215   (nnweb-possibly-change-server group server)
 216   (gnus-pull group nnweb-group-alist t)
 217   (nnweb-write-active)
 218   (gnus-delete-file (nnweb-overview-file group))
 219   t)
 220
 221 (nnoo-define-skeleton nnweb)
 222
 223 ;;; Internal functions
 224
 225 (defun nnweb-read-overview (group)
 226   "Read the overview of GROUP and build the map."
 227   (when (file-exists-p (nnweb-overview-file group))
 228     (mm-with-unibyte-buffer
 229       (nnheader-insert-file-contents (nnweb-overview-file group))
 230       (goto-char (point-min))
 231       (let (header)
 232         (while (not (eobp))
 233           (setq header (nnheader-parse-nov))
 234           (forward-line 1)
 235           (push (list (mail-header-number header)
 236                       header (mail-header-xref header))
 237                 nnweb-articles)
 238           (nnweb-set-hashtb header (car nnweb-articles)))))))
 239
 240 (defun nnweb-write-overview (group)
 241   "Write the overview file for GROUP."
 242   (with-temp-file (nnweb-overview-file group)
 243     (let ((articles nnweb-articles))
 244       (while articles
 245         (nnheader-insert-nov (cadr (pop articles)))))))
 246
 247 (defun nnweb-set-hashtb (header data)
 248   (gnus-sethash (nnweb-identifier (mail-header-xref header))
 249                 data nnweb-hashtb))
 250
 251 (defun nnweb-get-hashtb (url)
 252   (gnus-gethash (nnweb-identifier url) nnweb-hashtb))
 253
 254 (defun nnweb-identifier (ident)
 255   (funcall (nnweb-definition 'identifier) ident))
 256
 257 (defun nnweb-overview-file (group)
 258   "Return the name of the overview file of GROUP."
 259   (nnheader-concat nnweb-directory group ".overview"))
 260
 261 (defun nnweb-write-active ()
 262   "Save the active file."
 263   (gnus-make-directory nnweb-directory)
 264   (with-temp-file (nnheader-concat nnweb-directory "active")
 265     (prin1 `(setq nnweb-group-alist ',nnweb-group-alist) (current-buffer))))
 266
 267 (defun nnweb-read-active ()
 268   "Read the active file."
 269   (load (nnheader-concat nnweb-directory "active") t t t))
 270
 271 (defun nnweb-definition (type &optional noerror)
 272   "Return the definition of TYPE."
 273   (let ((def (cdr (assq type (assq nnweb-type nnweb-type-definition)))))
 274     (when (and (not def)
 275                (not noerror))
 276       (error "Undefined definition %s" type))
 277     def))
 278
 279 (defun nnweb-possibly-change-server (&optional group server)
 280   (when server
 281     (unless (nnweb-server-opened server)
 282       (nnweb-open-server server))
 283     (nnweb-init server))
 284   (unless nnweb-group-alist
 285     (nnweb-read-active))
 286   (unless nnweb-hashtb
 287     (setq nnweb-hashtb (gnus-make-hashtable 4095)))
 288   (when group
 289     (setq nnweb-group group)))
 290
 291 (defun nnweb-init (server)
 292   "Initialize buffers and such."
 293   (unless (gnus-buffer-live-p nnweb-buffer)
 294     (setq nnweb-buffer
 295           (save-current-buffer
 296             (nnheader-set-temp-buffer
 297              (format " *nnweb %s %s %s*"
 298                      nnweb-type nnweb-search server))
 299             (mm-disable-multibyte)
 300             (current-buffer)))))
 301
 302 ;;;
 303 ;;; groups.google.com
 304 ;;;
 305
 306 (defun nnweb-google-wash-article ()
 307   ;; We have Google's masked e-mail addresses here.  :-/
 308   (let ((case-fold-search t)
 309         (start-re "<pre>[\r\n ]*")
 310         (end-re "[\r\n ]*</pre>"))
 311     (goto-char (point-min))
 312     (if (save-excursion
 313           (or (re-search-forward "The requested message.*could not be found."
 314                                  nil t)
 315               (not (and (re-search-forward start-re nil t)
 316                         (re-search-forward end-re nil t)))))
 317         ;; FIXME: Don't know how to indicate "not found".
 318         ;; Should this function throw an error?  --rsteib
 319         (progn
 320           (gnus-message 3 "Requested article not found")
 321           (erase-buffer))
 322       (delete-region (point-min)
 323                      (re-search-forward start-re))
 324       (goto-char (point-min))
 325       (delete-region (progn
 326                        (re-search-forward end-re)
 327                        (match-beginning 0))
 328                      (point-max))
 329       (mm-url-decode-entities))))
 330
 331 (defun nnweb-google-parse-1 (&optional Message-ID)
 332   "Parse search result in current buffer."
 333   (let ((i 0)
 334         (case-fold-search t)
 335         (active (cadr (assoc nnweb-group nnweb-group-alist)))
 336         Subject Score Date Newsgroups From
 337         map url mid)
 338     (unless active
 339       (push (list nnweb-group (setq active (cons 1 0)))
 340             nnweb-group-alist))
 341     ;; Go through all the article hits on this page.
 342     (goto-char (point-min))
 343     (while
 344         (re-search-forward
 345          "a +href=\"/group/\\([^>\"]+\\)/browse_thread/[^>]+#\\([0-9a-f]+\\)"
 346          nil t)
 347       (setq Newsgroups (match-string-no-properties 1)
 348             ;; Note: Starting with Google Groups 2, `mid' is a Google-internal
 349             ;; ID, not a proper Message-ID.
 350             mid (match-string-no-properties 2)
 351             url (format
 352                  (nnweb-definition 'result) Newsgroups mid))
 353       (narrow-to-region (search-forward ">" nil t)
 354                         (search-forward "</a>" nil t))
 355       (mm-url-remove-markup)
 356       (mm-url-decode-entities)
 357       (setq Subject (buffer-string))
 358       (goto-char (point-max))
 359       (widen)
 360       (narrow-to-region (point)
 361                         (search-forward "</table" nil t))
 362
 363       (mm-url-remove-markup)
 364       (mm-url-decode-entities)
 365       (goto-char (point-max))
 366       (when
 367           (re-search-backward
 368            "^\\(?:\\(\\w+\\) \\([0-9]+\\)\\|\\S-+\\)\\(?: \\([0-9]\\{4\\}\\)\\)? by ?\\(.*\\)"
 369            nil t)
 370         (setq Date (if (match-string 1)
 371                        (format "%s %s 00:00:00 %s"
 372                                (match-string 1)
 373                                (match-string 2)
 374                                (or (match-string 3)
 375                                    (substring (current-time-string) -4)))
 376                      (current-time-string)))
 377         (setq From (match-string 4)))
 378       (widen)
 379       (incf i)
 380       (unless (nnweb-get-hashtb url)
 381         (push
 382          (list
 383           (incf (cdr active))
 384           (make-full-mail-header
 385            (cdr active) (if Newsgroups
 386                             (concat  "(" Newsgroups ") " Subject)
 387                           Subject)
 388            From Date (or Message-ID mid)
 389            nil 0 0 url))
 390          map)
 391         (nnweb-set-hashtb (cadar map) (car map))))
 392     map))
 393
 394 (defun nnweb-google-reference (id)
 395   (let ((map (nnweb-google-parse-1 id)) header)
 396     (setq nnweb-articles
 397           (nconc nnweb-articles map))
 398     (when (setq header (cadar map))
 399       (mm-with-unibyte-current-buffer
 400         (mm-url-insert (mail-header-xref header)))
 401       (caar map))))
 402
 403 (defun nnweb-google-create-mapping ()
 404   "Perform the search and create a number-to-url alist."
 405   (save-excursion
 406     (set-buffer nnweb-buffer)
 407     (erase-buffer)
 408     (nnheader-message 7 "Searching google...")
 409     (when (funcall (nnweb-definition 'search) nnweb-search)
 410         (let ((more t)
 411               (i 0))
 412           (while more
 413             (setq nnweb-articles
 414                   (nconc nnweb-articles (nnweb-google-parse-1)))
 415             ;; Check if there are more articles to fetch
 416             (goto-char (point-min))
 417             (incf i 100)
 418             (if (or (not (re-search-forward
 419                           "<a [^>]+href=\"\n?\\([^>\" \n\t]+\\)[^<]*<img[^>]+src=[^>]+next"
 420                           nil t))
 421                     (>= i nnweb-max-hits))
 422                 (setq more nil)
 423               ;; Yup, there are more articles
 424               (setq more (concat (nnweb-definition 'base) (match-string 1)))
 425             (when more
 426               (erase-buffer)
 427               (nnheader-message 7 "Searching google...(%d)" i)
 428               (mm-url-insert more))))
 429           ;; Return the articles in the right order.
 430           (nnheader-message 7 "Searching google...done")
 431           (setq nnweb-articles
 432                 (sort nnweb-articles 'car-less-than-car))))))
 433
 434 (defun nnweb-google-search (search)
 435   (mm-url-insert
 436    (concat
 437     (nnweb-definition 'address)
 438     "?"
 439     (mm-url-encode-www-form-urlencoded
 440      `(("q" . ,search)
 441        ("num" . ,(number-to-string
 442                   (min 100 nnweb-max-hits)))
 443        ("hq" . "")
 444        ("hl" . "en")
 445        ("lr" . "")
 446        ("safe" . "off")
 447        ("sites" . "groups")
 448        ("filter" . "0")))))
 449   t)
 450
 451 (defun nnweb-google-identity (url)
 452   "Return an unique identifier based on URL."
 453   (if (string-match "selm=\\([^ &>]+\\)" url)
 454       (match-string 1 url)
 455     url))
 456
 457 ;;;
 458 ;;; gmane.org
 459 ;;;
 460 (defun nnweb-gmane-create-mapping ()
 461   "Perform the search and create a number-to-url alist."
 462   (save-excursion
 463     (set-buffer nnweb-buffer)
 464     (let ((case-fold-search t)
 465           (active (or (cadr (assoc nnweb-group nnweb-group-alist))
 466                       (cons 1 0)))
 467           map)
 468       (erase-buffer)
 469       (nnheader-message 7 "Searching Gmane..." )
 470       (when (funcall (nnweb-definition 'search) nnweb-search)
 471         (goto-char (point-min))
 472         ;; Skip the status line
 473         (forward-line 1)
 474         ;; Thanks to Olly Betts we now have NOV lines in our buffer!
 475         (while (not (eobp))
 476           (unless (or (eolp) (looking-at "\x0d"))
 477             (let ((header (nnheader-parse-nov)))
 478               (let ((xref (mail-header-xref header))
 479                     (from (mail-header-from header))
 480                     (subject (mail-header-subject header))
 481                     (rfc2047-encoding-type 'mime))
 482                 (when (string-match " \\([^:]+\\)[:/]\\([0-9]+\\)" xref)
 483                   (mail-header-set-xref
 484                    header
 485                    (format "http://article.gmane.org/%s/%s/raw"
 486                            (match-string 1 xref)
 487                            (match-string 2 xref))))
 488
 489                 ;; Add host part to gmane-encrypted addresses
 490                 (when (string-match "@$" from)
 491                   (mail-header-set-from header
 492                                         (concat from "public.gmane.org")))
 493
 494                 (mail-header-set-subject header
 495                                          (rfc2047-encode-string subject))
 496
 497                 (unless (nnweb-get-hashtb (mail-header-xref header))
 498                   (mail-header-set-number header (incf (cdr active)))
 499                   (push (list (mail-header-number header) header) map)
 500                   (nnweb-set-hashtb (cadar map) (car map))))))
 501           (forward-line 1)))
 502       (nnheader-message 7 "Searching Gmane...done")
 503       (setq nnweb-articles
 504             (sort (nconc nnweb-articles map) 'car-less-than-car)))))
 505
 506 (defun nnweb-gmane-wash-article ()
 507   (let ((case-fold-search t))
 508     (goto-char (point-min))
 509     (when (search-forward "<!--X-Head-of-Message-->" nil t)
 510       (delete-region (point-min) (point))
 511       (goto-char (point-min))
 512       (while (looking-at "^<li><em>\\([^ ]+\\)</em>.*</li>")
 513         (replace-match "\\1\\2" t)
 514         (forward-line 1))
 515       (mm-url-remove-markup))))
 516
 517 (defun nnweb-gmane-search (search)
 518   (mm-url-insert
 519    (concat
 520     (nnweb-definition 'address)
 521     "?"
 522     (mm-url-encode-www-form-urlencoded
 523      `(("query" . ,search)
 524        ("HITSPERPAGE" . ,(number-to-string nnweb-max-hits))
 525        ;;("TOPDOC" . "1000")
 526        ))))
 527   (setq buffer-file-name nil)
 528   (set-buffer-multibyte t)
 529   (mm-decode-coding-region (point-min) (point-max) 'utf-8)
 530   t)
 531
 532 (defun nnweb-gmane-identity (url)
 533   "Return a unique identifier based on URL."
 534   (if (string-match "group=\\(.+\\)" url)
 535       (match-string 1 url)
 536     url))
 537
 538 ;;;
 539 ;;; General web/w3 interface utility functions
 540 ;;;
 541
 542 (defun nnweb-insert-html (parse)
 543   "Insert HTML based on a w3 parse tree."
 544   (if (stringp parse)
 545       ;; We used to call nnheader-string-as-multibyte here, but it cannot
 546       ;; be right, so I removed it.  If a bug shows up because of this change,
 547       ;; please do not blindly revert the change, but help me find the real
 548       ;; cause of the bug instead.  --Stef
 549       (insert parse)
 550     (insert "<" (symbol-name (car parse)) " ")
 551     (insert (mapconcat
 552              (lambda (param)
 553                (concat (symbol-name (car param)) "="
 554                        (prin1-to-string
 555                         (if (consp (cdr param))
 556                             (cadr param)
 557                           (cdr param)))))
 558              (nth 1 parse)
 559              " "))
 560     (insert ">\n")
 561     (mapc 'nnweb-insert-html (nth 2 parse))
 562     (insert "</" (symbol-name (car parse)) ">\n")))
 563
 564 (defun nnweb-parse-find (type parse &optional maxdepth)
 565   "Find the element of TYPE in PARSE."
 566   (catch 'found
 567     (nnweb-parse-find-1 type parse maxdepth)))
 568
 569 (defun nnweb-parse-find-1 (type contents maxdepth)
 570   (when (or (null maxdepth)
 571             (not (zerop maxdepth)))
 572     (when (consp contents)
 573       (when (eq (car contents) type)
 574         (throw 'found contents))
 575       (when (listp (cdr contents))
 576         (dolist (element contents)
 577           (when (consp element)
 578             (nnweb-parse-find-1 type element
 579                                 (and maxdepth (1- maxdepth)))))))))
 580
 581 (defun nnweb-parse-find-all (type parse)
 582   "Find all elements of TYPE in PARSE."
 583   (catch 'found
 584     (nnweb-parse-find-all-1 type parse)))
 585
 586 (defun nnweb-parse-find-all-1 (type contents)
 587   (let (result)
 588     (when (consp contents)
 589       (if (eq (car contents) type)
 590           (push contents result)
 591         (when (listp (cdr contents))
 592           (dolist (element contents)
 593             (when (consp element)
 594               (setq result
 595                     (nconc result (nnweb-parse-find-all-1 type element))))))))
 596     result))
 597
 598 (defvar nnweb-text)
 599 (defun nnweb-text (parse)
 600   "Return a list of text contents in PARSE."
 601   (let ((nnweb-text nil))
 602     (nnweb-text-1 parse)
 603     (nreverse nnweb-text)))
 604
 605 (defun nnweb-text-1 (contents)
 606   (dolist (element contents)
 607     (if (stringp element)
 608         (push element nnweb-text)
 609       (when (and (consp element)
 610                  (listp (cdr element)))
 611         (nnweb-text-1 element)))))
 612
 613 (provide 'nnweb)
 614
 615 ;; arch-tag: f59307eb-c90f-479f-b7d2-dbd8bf51b697
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