;;; spam-stat.el --- detecting spam based on statistics
-;; Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+;; Copyright (C) 2002-2011 Free Software Foundation, Inc.
;; Author: Alex Schroeder <alex@gnu.org>
;; Keywords: network
;; This file is part of GNU Emacs.
-;; This is free software; you can redistribute it and/or modify it
-;; under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
-;; any later version.
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
-;; This is distributed in the hope that it will be useful, but WITHOUT
-;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-;; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
-;; License for more details.
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
\f
;;; Code:
+(require 'mail-parse)
+
+(defvar gnus-original-article-buffer)
(defgroup spam-stat nil
"Statistical spam detection for Emacs.
Use the functions to build a dictionary of words and their statistical
distribution in spam and non-spam mails. Then use a function to determine
whether a buffer contains spam or not."
+ :version "22.1"
:group 'gnus)
(defcustom spam-stat-file "~/.spam-stat.el"
:group 'spam-stat)
(defcustom spam-stat-split-fancy-spam-group "mail.spam"
- "Name of the group where spam should be stored, if
-`spam-stat-split-fancy' is used in fancy splitting rules. Has no
-effect when spam-stat is invoked through spam.el."
+ "Name of the group where spam should be stored.
+If `spam-stat-split-fancy' is used in fancy splitting rules. Has
+no effect when spam-stat is invoked through spam.el."
:type 'string
:group 'spam-stat)
-(defcustom spam-stat-split-fancy-spam-threshhold 0.9
- "Spam score threshhold in spam-stat-split-fancy."
+(defcustom spam-stat-split-fancy-spam-threshold 0.9
+ "Spam score threshold in spam-stat-split-fancy."
+ :type 'number
+ :group 'spam-stat)
+
+(defcustom spam-stat-washing-hook nil
+ "Hook applied to each message before analysis."
+ :type 'hook
+ :group 'spam-stat)
+
+(defcustom spam-stat-score-buffer-user-functions nil
+ "List of additional scoring functions.
+Called one by one on the buffer.
+
+If all of these functions return non-nil answers, these numerical
+answers are added to the computed spam stat score on the buffer. If
+you defun such functions, make sure they don't return the buffer in a
+narrowed state or such: use, for example, `save-excursion'. Each of
+your functions is also passed the initial spam-stat score which might
+aid in your scoring.
+
+Also be careful when defining such functions. If they take a long
+time, they will slow down your mail splitting. Thus, if the buffer is
+large, don't forget to use smaller regions, by wrapping your work in,
+say, `with-spam-stat-max-buffer-size'."
+ :type '(repeat sexp)
+ :group 'spam-stat)
+
+(defcustom spam-stat-process-directory-age 90
+ "Max. age of files to be processed in directory, in days.
+When using `spam-stat-process-spam-directory' or
+`spam-stat-process-non-spam-directory', only files that have
+been touched in this many days will be considered. Without
+this filter, re-training spam-stat with several thousand messages
+will start to take a very long time."
:type 'number
:group 'spam-stat)
+(defvar spam-stat-last-saved-at nil
+ "Time stamp of last change of spam-stat-file on this run")
+
(defvar spam-stat-syntax-table
(let ((table (copy-syntax-table text-mode-syntax-table)))
(modify-syntax-entry ?- "w" table)
"Syntax table used when processing mails for statistical analysis.
The important part is which characters are word constituents.")
+(defvar spam-stat-dirty nil
+ "Whether the spam-stat database needs saving.")
+
(defvar spam-stat-buffer nil
"Buffer to use for scoring while splitting.
This is set by hooking into Gnus.")
(defvar spam-stat-buffer-name " *spam stat buffer*"
"Name of the `spam-stat-buffer'.")
-;; Functions missing in Emacs 20
-
-(when (memq nil (mapcar 'fboundp
- '(gethash hash-table-count make-hash-table
- mapc puthash)))
- (require 'cl)
- (unless (fboundp 'puthash)
- ;; alias puthash is missing from Emacs 20 cl-extra.el
- (defalias 'puthash 'cl-puthash)))
-
-(eval-when-compile
- (unless (fboundp 'with-syntax-table)
- ;; Imported from Emacs 21.2
- (defmacro with-syntax-table (table &rest body) "\
-Evaluate BODY with syntax table of current buffer set to a copy of TABLE.
-The syntax table of the current buffer is saved, BODY is evaluated, and the
-saved table is restored, even in case of an abnormal exit.
-Value is what BODY returns."
- (let ((old-table (make-symbol "table"))
- (old-buffer (make-symbol "buffer")))
- `(let ((,old-table (syntax-table))
- (,old-buffer (current-buffer)))
- (unwind-protect
- (progn
- (set-syntax-table (copy-syntax-table ,table))
- ,@body)
- (save-current-buffer
- (set-buffer ,old-buffer)
- (set-syntax-table ,old-table))))))))
+(defvar spam-stat-coding-system
+ (if (mm-coding-system-p 'emacs-mule) 'emacs-mule 'raw-text)
+ "Coding system used for `spam-stat-file'.")
;; Hooking into Gnus
(defun spam-stat-store-current-buffer ()
"Store a copy of the current buffer in `spam-stat-buffer'."
- (save-excursion
- (let ((str (buffer-string)))
- (set-buffer (get-buffer-create spam-stat-buffer-name))
+ (let ((buf (current-buffer)))
+ (with-current-buffer (get-buffer-create spam-stat-buffer-name)
(erase-buffer)
- (insert str)
+ (insert-buffer-substring buf)
(setq spam-stat-buffer (current-buffer)))))
(defun spam-stat-store-gnus-article-buffer ()
"Store a copy of the current article in `spam-stat-buffer'.
This uses `gnus-article-buffer'."
- (save-excursion
- (set-buffer gnus-original-article-buffer)
+ (with-current-buffer gnus-original-article-buffer
(spam-stat-store-current-buffer)))
-(when spam-stat-install-hooks
- (add-hook 'nnmail-prepare-incoming-message-hook
- 'spam-stat-store-current-buffer)
- (add-hook 'gnus-select-article-hook
- 'spam-stat-store-gnus-article-buffer))
-
;; Data -- not using defstruct in order to save space and time
(defvar spam-stat (make-hash-table :test 'equal)
(defvar spam-stat-nbad 0
"The number of bad mails in the dictionary.")
+(defvar spam-stat-error-holder nil
+ "A holder for condition-case errors while scoring buffers.")
+
(defsubst spam-stat-good (entry)
"Return the number of times this word belongs to good mails."
(aref entry 0))
;; Parsing
(defmacro with-spam-stat-max-buffer-size (&rest body)
- "Narrows the buffer down to the first 4k characters, then evaluates BODY."
+ "Narrow the buffer down to the first 4k characters, then evaluate BODY."
`(save-restriction
(when (> (- (point-max)
(point-min))
,@body))
(defun spam-stat-buffer-words ()
- "Return a hash table of words and number of occurences in the buffer."
+ "Return a hash table of words and number of occurrences in the buffer."
+ (run-hooks 'spam-stat-washing-hook)
(with-spam-stat-max-buffer-size
(with-syntax-table spam-stat-syntax-table
(goto-char (point-min))
(setq entry (spam-stat-make-entry 0 count)))
(spam-stat-set-score entry (spam-stat-compute-score entry))
(puthash word entry spam-stat)))
- (spam-stat-buffer-words)))
+ (spam-stat-buffer-words))
+ (setq spam-stat-dirty t))
(defun spam-stat-buffer-is-non-spam ()
"Consider current buffer to be a new non-spam mail."
(setq entry (spam-stat-make-entry count 0)))
(spam-stat-set-score entry (spam-stat-compute-score entry))
(puthash word entry spam-stat)))
- (spam-stat-buffer-words)))
+ (spam-stat-buffer-words))
+ (setq spam-stat-dirty t))
+
+(autoload 'gnus-message "gnus-util")
(defun spam-stat-buffer-change-to-spam ()
"Consider current buffer no longer normal mail but spam."
(lambda (word count)
(let ((entry (gethash word spam-stat)))
(if (not entry)
- (error "This buffer has unknown words in it.")
+ (gnus-message 8 "This buffer has unknown words in it")
(spam-stat-set-good entry (- (spam-stat-good entry) count))
(spam-stat-set-bad entry (+ (spam-stat-bad entry) count))
(spam-stat-set-score entry (spam-stat-compute-score entry))
(puthash word entry spam-stat))))
- (spam-stat-buffer-words)))
+ (spam-stat-buffer-words))
+ (setq spam-stat-dirty t))
(defun spam-stat-buffer-change-to-non-spam ()
"Consider current buffer no longer spam but normal mail."
(lambda (word count)
(let ((entry (gethash word spam-stat)))
(if (not entry)
- (error "This buffer has unknown words in it.")
+ (gnus-message 8 "This buffer has unknown words in it")
(spam-stat-set-good entry (+ (spam-stat-good entry) count))
(spam-stat-set-bad entry (- (spam-stat-bad entry) count))
(spam-stat-set-score entry (spam-stat-compute-score entry))
(puthash word entry spam-stat))))
- (spam-stat-buffer-words)))
+ (spam-stat-buffer-words))
+ (setq spam-stat-dirty t))
;; Saving and Loading
-(defun spam-stat-save ()
- "Save the `spam-stat' hash table as lisp file."
- (interactive)
- (with-temp-buffer
- (let ((standard-output (current-buffer))
- (font-lock-maximum-size 0))
- (insert "(setq spam-stat-ngood "
- (number-to-string spam-stat-ngood)
- " spam-stat-nbad "
- (number-to-string spam-stat-nbad)
- " spam-stat (spam-stat-to-hash-table '(")
- (maphash (lambda (word entry)
- (prin1 (list word
- (spam-stat-good entry)
- (spam-stat-bad entry))))
- spam-stat)
- (insert ")))")
- (write-file spam-stat-file))))
+(defun spam-stat-save (&optional force)
+ "Save the `spam-stat' hash table as lisp file.
+With a prefix argument save unconditionally."
+ (interactive "P")
+ (when (or force spam-stat-dirty)
+ (let ((coding-system-for-write spam-stat-coding-system))
+ (with-temp-file spam-stat-file
+ (let ((standard-output (current-buffer))
+ (font-lock-maximum-size 0))
+ (insert (format ";-*- coding: %s; -*-\n" spam-stat-coding-system))
+ (insert (format "(setq spam-stat-ngood %d spam-stat-nbad %d
+spam-stat (spam-stat-to-hash-table '(" spam-stat-ngood spam-stat-nbad))
+ (maphash (lambda (word entry)
+ (prin1 (list word
+ (spam-stat-good entry)
+ (spam-stat-bad entry))))
+ spam-stat)
+ (insert ")))"))))
+ (message "Saved %s." spam-stat-file)
+ (setq spam-stat-dirty nil
+ spam-stat-last-saved-at (nth 5 (file-attributes spam-stat-file)))))
(defun spam-stat-load ()
"Read the `spam-stat' hash table from disk."
- (load-file spam-stat-file))
+ ;; TODO: maybe we should warn the user if spam-stat-dirty is t?
+ (let ((coding-system-for-read spam-stat-coding-system))
+ (cond (spam-stat-dirty (message "Spam stat not loaded: spam-stat-dirty t"))
+ ((or (not (boundp 'spam-stat-last-saved-at))
+ (null spam-stat-last-saved-at)
+ (not (equal spam-stat-last-saved-at
+ (nth 5 (file-attributes spam-stat-file)))))
+ (progn
+ (load-file spam-stat-file)
+ (setq spam-stat-dirty nil
+ spam-stat-last-saved-at
+ (nth 5 (file-attributes spam-stat-file)))))
+ (t (message "Spam stat file not loaded: no change in disk.")))))
(defun spam-stat-to-hash-table (entries)
"Turn list ENTRIES into a hash table and store as `spam-stat'.
NBAD is the number of bad mails it has appeared in, GOOD is the number
of times it appeared in good mails, and BAD is the number of times it
has appeared in bad mails."
- (let ((table (make-hash-table :test 'equal)))
+ (let ((table (make-hash-table :size (length entries)
+ :test 'equal)))
(mapc (lambda (l)
(puthash (car l)
(spam-stat-make-entry (nth 1 l) (nth 2 l))
(interactive)
(setq spam-stat (make-hash-table :test 'equal)
spam-stat-ngood 0
- spam-stat-nbad 0))
+ spam-stat-nbad 0)
+ (setq spam-stat-dirty t))
;; Scoring buffers
These are the words whose spam-stat differs the most from 0.5.
The list returned contains elements of the form \(WORD SCORE DIFF),
where DIFF is the difference between SCORE and 0.5."
- (with-spam-stat-max-buffer-size
- (with-syntax-table spam-stat-syntax-table
- (let (result word score)
- (maphash (lambda (word ignore)
- (setq score (spam-stat-score-word word)
- result (cons (list word score (abs (- score 0.5)))
- result)))
- (spam-stat-buffer-words))
- (setq result (sort result (lambda (a b) (< (nth 2 b) (nth 2 a)))))
- (setcdr (nthcdr 14 result) nil)
- result))))
+ (let (result word score)
+ (maphash (lambda (word ignore)
+ (setq score (spam-stat-score-word word)
+ result (cons (list word score (abs (- score 0.5)))
+ result)))
+ (spam-stat-buffer-words))
+ (setq result (sort result (lambda (a b) (< (nth 2 b) (nth 2 a)))))
+ (setcdr (nthcdr 14 result) nil)
+ result))
(defun spam-stat-score-buffer ()
- "Return a score describing the spam-probability for this buffer."
+ "Return a score describing the spam-probability for this buffer.
+Add user supplied modifications if supplied."
+ (interactive) ; helps in debugging.
(setq spam-stat-score-data (spam-stat-buffer-words-with-scores))
- (let* ((probs (mapcar (lambda (e) (cadr e)) spam-stat-score-data))
- (prod (apply #'* probs)))
- (/ prod (+ prod (apply #'* (mapcar #'(lambda (x) (- 1 x))
- probs))))))
+ (let* ((probs (mapcar 'cadr spam-stat-score-data))
+ (prod (apply #'* probs))
+ (score0
+ (/ prod (+ prod (apply #'* (mapcar #'(lambda (x) (- 1 x))
+ probs)))))
+ (score1s
+ (condition-case
+ spam-stat-error-holder
+ (spam-stat-score-buffer-user score0)
+ (error nil)))
+ (ans
+ (if score1s (+ score0 score1s) score0)))
+ (when (interactive-p)
+ (message "%S" ans))
+ ans))
+
+(defun spam-stat-score-buffer-user (&rest args)
+ (let* ((scores
+ (mapcar
+ (lambda (fn)
+ (apply fn args))
+ spam-stat-score-buffer-user-functions)))
+ (if (memq nil scores) nil
+ (apply #'+ scores))))
(defun spam-stat-split-fancy ()
"Return the name of the spam group if the current mail is spam.
Use this function on `nnmail-split-fancy'. If you are interested in
the raw data used for the last run of `spam-stat-score-buffer',
check the variable `spam-stat-score-data'."
- (condition-case var
+ (condition-case spam-stat-error-holder
(progn
(set-buffer spam-stat-buffer)
(goto-char (point-min))
- (when (> (spam-stat-score-buffer) spam-stat-split-fancy-spam-threshhold)
+ (when (> (spam-stat-score-buffer) spam-stat-split-fancy-spam-threshold)
(when (boundp 'nnmail-split-trace)
(mapc (lambda (entry)
(push entry nnmail-split-trace))
spam-stat-score-data))
spam-stat-split-fancy-spam-group))
- (error (message "Error in spam-stat-split-fancy: %S" var)
+ (error (message "Error in spam-stat-split-fancy: %S" spam-stat-error-holder)
nil)))
;; Testing
+(defun spam-stat-strip-xref ()
+ "Strip the Xref header."
+ (save-restriction
+ (mail-narrow-to-head)
+ (when (re-search-forward "^Xref:.*\n" nil t)
+ (delete-region (match-beginning 0) (match-end 0)))))
+
+(autoload 'time-to-number-of-days "time-date")
+
(defun spam-stat-process-directory (dir func)
"Process all the regular files in directory DIR using function FUNC."
(let* ((files (directory-files dir t "^[^.]"))
(dolist (f files)
(when (and (file-readable-p f)
(file-regular-p f)
- (> (nth 7 (file-attributes f)) 0))
+ (> (nth 7 (file-attributes f)) 0)
+ (< (time-to-number-of-days (time-since (nth 5 (file-attributes f))))
+ spam-stat-process-directory-age))
(setq count (1+ count))
(message "Reading %s: %.2f%%" dir (/ count max))
- (insert-file-contents f)
+ (insert-file-contents-literally f)
+ (spam-stat-strip-xref)
(funcall func)
(erase-buffer))))))
(interactive)
(hash-table-count spam-stat))
-(defun spam-stat-test-directory (dir)
+(defun spam-stat-test-directory (dir &optional verbose)
"Test all the regular files in directory DIR for spam.
If the result is 1.0, then all files are considered spam.
If the result is 0.0, non of the files is considered spam.
-You can use this to determine error rates."
- (interactive "D")
+You can use this to determine error rates.
+
+If VERBOSE is non-nil display names of files detected as spam or
+non-spam in a temporary buffer. If it is the symbol `ham',
+display non-spam files; otherwise display spam files."
+ (interactive "DDirectory: ")
(let* ((files (directory-files dir t "^[^.]"))
+ display-files
+ buffer-score
(total (length files))
(score 0.0); float
(max (/ total 100.0)); float
(dolist (f files)
(when (and (file-readable-p f)
(file-regular-p f)
- (> (nth 7 (file-attributes f))))
+ (> (nth 7 (file-attributes f)) 0))
(setq count (1+ count))
- (message "Reading %.2f%%, score %.2f%%"
- (/ count max) (/ score count))
- (insert-file-contents f)
- (when (> (spam-stat-score-buffer) 0.9)
+ (message "Reading %.2f%%, score %.2f"
+ (/ count max) (/ score count))
+ (insert-file-contents-literally f)
+ (setq buffer-score (spam-stat-score-buffer))
+ (when (> buffer-score 0.9)
(setq score (1+ score)))
+ (when verbose
+ (if (> buffer-score 0.9)
+ (unless (eq verbose 'ham) (push f display-files))
+ (when (eq verbose 'ham) (push f display-files))))
(erase-buffer))))
+ (when display-files
+ (with-output-to-temp-buffer "*spam-stat results*"
+ (dolist (file display-files)
+ (princ file)
+ (terpri))))
(message "Final score: %d / %d = %f" score total (/ score total))))
;; Shrinking the dictionary
(spam-stat-bad entry))
count)
(remhash key spam-stat)))
- spam-stat))
+ spam-stat)
+ (setq spam-stat-dirty t))
+
+(defun spam-stat-install-hooks-function ()
+ "Install the spam-stat function hooks."
+ (interactive)
+ (add-hook 'nnmail-prepare-incoming-message-hook
+ 'spam-stat-store-current-buffer)
+ (add-hook 'gnus-select-article-hook
+ 'spam-stat-store-gnus-article-buffer))
+
+(when spam-stat-install-hooks
+ (spam-stat-install-hooks-function))
+
+(defun spam-stat-unload-hook ()
+ "Uninstall the spam-stat function hooks."
+ (interactive)
+ (remove-hook 'nnmail-prepare-incoming-message-hook
+ 'spam-stat-store-current-buffer)
+ (remove-hook 'gnus-select-article-hook
+ 'spam-stat-store-gnus-article-buffer))
+
+(add-hook 'spam-stat-unload-hook 'spam-stat-unload-hook)
(provide 'spam-stat)
projects / gnus / blobdiff