lisp/url/url-history.el

   1 ;;; url-history.el --- Global history tracking for URL package
   2
   3 ;; Copyright (C) 1996-1999, 2004-2017 Free Software Foundation, Inc.
   4
   5 ;; Keywords: comm, data, processes, hypermedia
   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 3 of the License, or
  12 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 ;;; Commentary:
  23
  24 ;;; Code:
  25
  26 ;; This can get a recursive require.
  27 ;;(require 'url)
  28 (require 'url-parse)
  29 (autoload 'url-do-setup "url")
  30
  31 (defgroup url-history nil
  32   "History variables in the URL package."
  33   :prefix "url-history"
  34   :group 'url)
  35
  36 (defcustom url-history-track nil
  37   "Controls whether to keep a list of all the URLs being visited.
  38 If non-nil, the URL package will keep track of all the URLs visited.
  39 If set to t, then the list is saved to disk at the end of each Emacs
  40 session."
  41   :set #'(lambda (var val)
  42            (set-default var val)
  43            (and (bound-and-true-p url-setup-done)
  44                 (url-history-setup-save-timer)))
  45   :type '(choice (const :tag "off" nil)
  46                  (const :tag "on" t)
  47                  (other :tag "within session" session))
  48   :group 'url-history)
  49
  50 (defcustom url-history-file nil
  51   "The global history file for the URL package.
  52 This file contains a list of all the URLs you have visited.  This file
  53 is parsed at startup and used to provide URL completion."
  54   :type '(choice (const :tag "Default" :value nil) file)
  55   :group 'url-history)
  56
  57 (defcustom url-history-save-interval 3600
  58   "The number of seconds between automatic saves of the history list.
  59 Default is 1 hour.  Note that if you change this variable outside of
  60 the `customize' interface after `url-do-setup' has been run, you need
  61 to run the `url-history-setup-save-timer' function manually."
  62   :set #'(lambda (var val)
  63            (set-default var val)
  64            (if (bound-and-true-p url-setup-done)
  65                (url-history-setup-save-timer)))
  66   :type 'integer
  67   :group 'url-history)
  68
  69 (defvar url-history-timer nil)
  70
  71 (defvar url-history-changed-since-last-save nil
  72   "Whether the history list has changed since the last save operation.")
  73
  74 (defvar url-history-hash-table (make-hash-table :size 31 :test 'equal)
  75   "Hash table for global history completion.")
  76
  77 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  78
  79 (defun url-history-setup-save-timer ()
  80   "Reset the history list timer."
  81   (interactive)
  82   (condition-case nil
  83       (cancel-timer url-history-timer)
  84     (error nil))
  85   (setq url-history-timer nil)
  86   (if (and (eq url-history-track t) url-history-save-interval)
  87       (setq url-history-timer (run-at-time url-history-save-interval
  88                                            url-history-save-interval
  89                                            'url-history-save-history))))
  90
  91 (defun url-history-parse-history (&optional fname)
  92   "Parse a history file stored in FNAME."
  93   ;; Parse out the mosaic global history file for completions, etc.
  94   (or fname (setq fname (expand-file-name url-history-file)))
  95   (cond
  96    ((not (file-exists-p fname))
  97     ;; It's completely normal for this file not to exist, so don't complain.
  98     ;; (message "%s does not exist." fname)
  99     )
 100    ((not (file-readable-p fname))
 101     (message "%s is unreadable." fname))
 102    (t
 103     (condition-case nil
 104         (load fname nil t)
 105       (error (message "Could not load %s" fname))))))
 106
 107 (defun url-history-update-url (url time)
 108   (setq url-history-changed-since-last-save t)
 109   (puthash (if (vectorp url) (url-recreate-url url) url) time
 110            url-history-hash-table))
 111
 112 (autoload 'url-make-private-file "url-util")
 113
 114 (defun url-history-save-history (&optional fname)
 115   "Write the global history file into `url-history-file'.
 116 The type of data written is determined by what is in the file to begin
 117 with.  If the type of storage cannot be determined, then prompt the
 118 user for what type to save as."
 119   (interactive)
 120   (when url-history-changed-since-last-save
 121     (or fname (setq fname (expand-file-name url-history-file)))
 122     (if (condition-case nil
 123             (progn
 124               (url-make-private-file fname)
 125               nil)
 126           (error t))
 127         (message "Error accessing history file `%s'" fname)
 128       (let ((make-backup-files nil)
 129             (version-control nil)
 130             (require-final-newline t)
 131             (count 0))
 132         (with-temp-buffer
 133           (maphash (lambda (key value)
 134                      (while (string-match "[\r\n]+" key)
 135                        (setq key (concat (substring key 0 (match-beginning 0))
 136                                          (substring key (match-end 0) nil))))
 137                      (setq count (1+ count))
 138                      (insert "(puthash \"" key "\""
 139                              (if (not (stringp value)) " '" "")
 140                              (prin1-to-string value)
 141                              " url-history-hash-table)\n"))
 142                    url-history-hash-table)
 143           ;; We used to add this in the file, but it just makes the code
 144           ;; more complex with no benefit.  Worse: it makes it harder to
 145           ;; preserve preexisting history when loading the history file.
 146           ;; (goto-char (point-min))
 147           ;; (insert (format
 148           ;;          "(setq url-history-hash-table (make-hash-table :size %d :test 'equal))\n"
 149           ;;          (/ count 4)))
 150           ;; (goto-char (point-max))
 151           (insert "\n")
 152           (write-file fname)))
 153       (setq url-history-changed-since-last-save nil))))
 154
 155 (defun url-have-visited-url (url)
 156   (url-do-setup)
 157   (gethash url url-history-hash-table nil))
 158
 159 (defun url-completion-function (string predicate function)
 160   ;; Completion function to complete urls from the history.
 161   ;; This is obsolete since we can now pass the hash-table directly as a
 162   ;; completion table.
 163   (url-do-setup)
 164   (cond
 165    ((eq function nil)
 166     (let ((list nil))
 167       (maphash (lambda (key val) (push key list))
 168                url-history-hash-table)
 169       ;; Not sure why we bother reversing the list.  --Stef
 170       (try-completion string (nreverse list) predicate)))
 171    ((eq function t)
 172     (let ((stub (concat "\\`" (regexp-quote string)))
 173           (retval nil))
 174       (maphash
 175        (lambda (url time)
 176          (if (string-match stub url) (push url retval)))
 177        url-history-hash-table)
 178       retval))
 179    ((eq function 'lambda)
 180     (and (gethash string url-history-hash-table) t))
 181    (t
 182     (error "url-completion-function very confused"))))
 183
 184 (provide 'url-history)
 185
 186 ;;; url-history.el ends here