lisp/gnus/gnus-logic.el

   1 ;;; gnus-logic.el --- advanced scoring code for Gnus
   2
   3 ;; Copyright (C) 1996-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
   6 ;; Keywords: news
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28
  29 (require 'gnus)
  30 (require 'gnus-score)
  31 (require 'gnus-util)
  32
  33 ;;; Internal variables.
  34
  35 (defvar gnus-advanced-headers nil)
  36
  37 ;; To avoid having 8-bit characters in the source file.
  38 (defvar gnus-advanced-not (intern (format "%c" 172)))
  39
  40 (defconst gnus-advanced-index
  41   ;; Name to index alist.
  42   '(("number" 0 gnus-advanced-integer)
  43     ("subject" 1 gnus-advanced-string)
  44     ("from" 2 gnus-advanced-string)
  45     ("date" 3 gnus-advanced-date)
  46     ("message-id" 4 gnus-advanced-string)
  47     ("references" 5 gnus-advanced-string)
  48     ("chars" 6 gnus-advanced-integer)
  49     ("lines" 7 gnus-advanced-integer)
  50     ("xref" 8 gnus-advanced-string)
  51     ("head" nil gnus-advanced-body)
  52     ("body" nil gnus-advanced-body)
  53     ("all" nil gnus-advanced-body)))
  54
  55 (autoload 'parse-time-string "parse-time")
  56
  57 (defun gnus-score-advanced (rule &optional trace)
  58   "Apply advanced scoring RULE to all the articles in the current group."
  59   (let (new-score score multiple)
  60     (dolist (gnus-advanced-headers gnus-newsgroup-headers)
  61       (when (setq multiple (gnus-advanced-score-rule (car rule)))
  62         (setq new-score (or (nth 1 rule)
  63                             gnus-score-interactive-default-score))
  64         (when (numberp multiple)
  65           (setq new-score (* multiple new-score)))
  66         ;; This rule was successful, so we add the score to this
  67         ;; article.
  68         (if (setq score (assq (mail-header-number gnus-advanced-headers)
  69                               gnus-newsgroup-scored))
  70             (setcdr score
  71                     (+ (cdr score) new-score))
  72           (push (cons (mail-header-number gnus-advanced-headers)
  73                       new-score)
  74                 gnus-newsgroup-scored)
  75           (when trace
  76             (push (cons "A file" rule)
  77                   ;; Must be synced with `gnus-score-edit-file-at-point'.
  78                   gnus-score-trace)))))))
  79
  80 (defun gnus-advanced-score-rule (rule)
  81   "Apply RULE to `gnus-advanced-headers'."
  82   (let ((type (car rule)))
  83     (cond
  84      ;; "And" rule.
  85      ((or (eq type '&) (eq type 'and))
  86       (pop rule)
  87       (if (not rule)
  88           t                             ; Empty rule is true.
  89         (while (and rule
  90                     (gnus-advanced-score-rule (car rule)))
  91           (pop rule))
  92         ;; If all the rules were true, then `rule' should be nil.
  93         (not rule)))
  94      ;; "Or" rule.
  95      ((or (eq type '|) (eq type 'or))
  96       (pop rule)
  97       (if (not rule)
  98           nil
  99         (while (and rule
 100                     (not (gnus-advanced-score-rule (car rule))))
 101           (pop rule))
 102         ;; If one of the rules returned true, then `rule' should be non-nil.
 103         rule))
 104      ;; "Not" rule.
 105      ((or (eq type '!) (eq type 'not) (eq type gnus-advanced-not))
 106       (not (gnus-advanced-score-rule (nth 1 rule))))
 107      ;; This is a `1-'-type redirection rule.
 108      ((and (symbolp type)
 109            (string-match "^[0-9]+-$\\|^\\^+$" (symbol-name type)))
 110       (let ((gnus-advanced-headers
 111              (gnus-parent-headers
 112               gnus-advanced-headers
 113               (if (string-match "^\\([0-9]+\\)-$" (symbol-name type))
 114                   ;; 1- type redirection.
 115                   (string-to-number
 116                    (substring (symbol-name type)
 117                               (match-beginning 1) (match-end 1)))
 118                 ;; ^^^ type redirection.
 119                 (length (symbol-name type))))))
 120         (when gnus-advanced-headers
 121           (gnus-advanced-score-rule (nth 1 rule)))))
 122      ;; Plain scoring rule.
 123      ((stringp type)
 124       (gnus-advanced-score-article rule))
 125      ;; Bug-out time!
 126      (t
 127       (error "Unknown advanced score type: %s" rule)))))
 128
 129 (defun gnus-advanced-score-article (rule)
 130   ;; `rule' is a semi-normal score rule, so we find out what function
 131   ;; that's supposed to do the actual processing.
 132   (let* ((header (car rule))
 133          (func (assoc (downcase header) gnus-advanced-index)))
 134     (if (not func)
 135         (error "No such header: %s" rule)
 136       ;; Call the score function.
 137       (funcall (caddr func) (or (cadr func) header)
 138                (cadr rule) (caddr rule)))))
 139
 140 (defun gnus-advanced-string (index match type)
 141   "See whether string MATCH of TYPE matches `gnus-advanced-headers' in INDEX."
 142   (let* ((type (or type 's))
 143          (case-fold-search (not (eq (downcase (symbol-name type))
 144                                     (symbol-name type))))
 145          (header (or (aref gnus-advanced-headers index) "")))
 146     (cond
 147      ((memq type '(r R regexp Regexp))
 148       (string-match match header))
 149      ((memq type '(s S string String))
 150       (string-match (regexp-quote match) header))
 151      ((memq type '(e E exact Exact))
 152       (string= match header))
 153      ((memq type '(f F fuzzy Fuzzy))
 154       (string-match (regexp-quote (gnus-simplify-subject-fuzzy match))
 155                     header))
 156      (t
 157       (error "No such string match type: %s" type)))))
 158
 159 (defun gnus-advanced-integer (index match type)
 160   (if (not (memq type '(< > <= >= =)))
 161       (error "No such integer score type: %s" type)
 162     (funcall type (or (aref gnus-advanced-headers index) 0) match)))
 163
 164 (defun gnus-advanced-date (index match type)
 165   (let ((date (apply 'encode-time (parse-time-string
 166                                    (aref gnus-advanced-headers index))))
 167         (match (apply 'encode-time (parse-time-string match))))
 168     (cond
 169      ((eq type 'at)
 170       (equal date match))
 171      ((eq type 'before)
 172       (time-less-p match date))
 173      ((eq type 'after)
 174       (time-less-p date match))
 175      (t
 176       (error "No such date score type: %s" type)))))
 177
 178 (defun gnus-advanced-body (header match type)
 179   (when (string= header "all")
 180     (setq header "article"))
 181   (with-current-buffer nntp-server-buffer
 182     (let* ((request-func (cond ((string= "head" header)
 183                                 'gnus-request-head)
 184                                ((string= "body" header)
 185                                 'gnus-request-body)
 186                                (t 'gnus-request-article)))
 187            ofunc article handles)
 188       ;; Not all backends support partial fetching.  In that case, we
 189       ;; just fetch the entire article.
 190       ;; When scoring by body, we need to peek at the headers to detect the
 191       ;; content encoding
 192       (unless (or (gnus-check-backend-function
 193                    (intern (concat "request-" header))
 194                    gnus-newsgroup-name)
 195                   (string= "body" header))
 196         (setq ofunc request-func)
 197         (setq request-func 'gnus-request-article))
 198       (setq article (mail-header-number gnus-advanced-headers))
 199       (gnus-message 7 "Scoring article %s..." article)
 200       (when (funcall request-func article gnus-newsgroup-name)
 201         (when (string= "body" header)
 202           (setq handles (gnus-score-decode-text-parts)))
 203         (goto-char (point-min))
 204         ;; If just parts of the article is to be searched and the
 205         ;; backend didn't support partial fetching, we just narrow to
 206         ;; the relevant parts.
 207         (when ofunc
 208           (if (eq ofunc 'gnus-request-head)
 209               (narrow-to-region
 210                (point)
 211                (or (search-forward "\n\n" nil t) (point-max)))
 212             (narrow-to-region
 213              (or (search-forward "\n\n" nil t) (point))
 214              (point-max))))
 215         (let* ((case-fold-search (not (eq (downcase (symbol-name type))
 216                                           (symbol-name type))))
 217                (search-func
 218                 (cond ((memq type '(r R regexp Regexp))
 219                        're-search-forward)
 220                       ((memq type '(s S string String))
 221                        'search-forward)
 222                       (t
 223                        (error "Invalid match type: %s" type)))))
 224           (goto-char (point-min))
 225           (prog1
 226               (funcall search-func match nil t)
 227             (widen)))
 228         (when handles (mm-destroy-parts handles))))))
 229
 230 (provide 'gnus-logic)
 231
 232 ;;; gnus-logic.el ends here