Merge changes from emacs-23 branch

[bpt/emacs.git] / lisp / url / url-cache.el

diff --git a/lisp/url/url-cache.el b/lisp/url/url-cache.el
index 44aa027..53222cb 100644 (file)
--- a/lisp/url/url-cache.el
+++ b/lisp/url/url-cache.el
@@ -1,7 +1,7 @@
 ;;; url-cache.el --- Uniform Resource Locator retrieval tool
 
-;; Copyright (C) 1996, 1997, 1998, 1999, 2004,
-;;   2005, 2006, 2007, 2008  Free Software Foundation, Inc.
+;; Copyright (C) 1996, 1997, 1998, 1999, 2004, 2005, 2006, 2007, 2008,
+;;   2009, 2010  Free Software Foundation, Inc.
 
 ;; Keywords: comm, data, processes, hypermedia
 
@@ -28,10 +28,17 @@
 
 (defcustom url-cache-directory
   (expand-file-name "cache" url-configuration-directory)
-  "*The directory where cache files should be stored."
+  "The directory where cache files should be stored."
   :type 'directory
   :group 'url-file)
 
+(defcustom url-cache-expire-time 3600
+  "Default maximum time in seconds before cache files expire.
+Used by the function `url-cache-expired'."
+  :version "24.1"
+  :type 'integer
+  :group 'url-cache)
+
 ;; Cache manager
 (defun url-cache-file-writable-p (file)
   "Follows the documentation of `file-writable-p', unlike `file-writable-p'."
@@ -62,18 +69,22 @@ FILE can be created or overwritten."
 ;;;###autoload
 (defun url-store-in-cache (&optional buff)
   "Store buffer BUFF in the cache."
-  (if (not (and buff (get-buffer buff)))
-      nil
-    (save-current-buffer
-      (and buff (set-buffer buff))
-      (let* ((fname (url-cache-create-filename (url-view-url t))))
-       (if (url-cache-prepare fname)
-           (let ((coding-system-for-write 'binary))
-             (write-region (point-min) (point-max) fname nil 5)))))))
+    (with-current-buffer (get-buffer (or buff (current-buffer)))
+      (let ((fname (url-cache-create-filename (url-view-url t))))
+        (if (url-cache-prepare fname)
+            (let ((coding-system-for-write 'binary))
+              (write-region (point-min) (point-max) fname nil 5))))))
+
+(defun url-fetch-from-cache (url)
+  "Fetch URL from cache and return a buffer with the content."
+  (with-current-buffer (generate-new-buffer " *temp*")
+    (url-cache-extract (url-cache-create-filename url))
+    (current-buffer)))
 
 ;;;###autoload
 (defun url-is-cached (url)
-  "Return non-nil if the URL is cached."
+  "Return non-nil if the URL is cached.
+The actual return value is the last modification time of the cache file."
   (let* ((fname (url-cache-create-filename url))
         (attribs (file-attributes fname)))
     (and fname                         ; got a filename
@@ -165,7 +176,7 @@ Very fast if you have an `md5' primitive function, suitably fast otherwise."
                                url-cache-directory))))))
 
 (defcustom url-cache-creation-function 'url-cache-create-filename-using-md5
-  "*What function to use to create a cached filename."
+  "What function to use to create a cached filename."
   :type '(choice (const :tag "MD5 of filename (low collision rate)"
                        :value url-cache-create-filename-using-md5)
                 (const :tag "Human readable filenames (higher collision rate)"
@@ -182,22 +193,19 @@ Very fast if you have an `md5' primitive function, suitably fast otherwise."
   (erase-buffer)
   (insert-file-contents-literally fnam))
 
-;;;###autoload
-(defun url-cache-expired (url mod)
-  "Return t if a cached file has expired."
-  (let* ((urlobj (if (vectorp url) url (url-generic-parse-url url)))
-        (type (url-type urlobj)))
-    (cond
-     (url-standalone-mode
-      (not (file-exists-p (url-cache-create-filename url))))
-     ((string= type "http")
-      t)
-     ((member type '("file" "ftp"))
-      (if (or (equal mod '(0 0)) (not mod))
-         t
-       (or (> (nth 0 mod) (nth 0 (current-time)))
-           (> (nth 1 mod) (nth 1 (current-time))))))
-     (t nil))))
+(defun url-cache-expired (url &optional expire-time)
+  "Return non-nil if a cached URL is older than EXPIRE-TIME seconds.
+The default value of EXPIRE-TIME is `url-cache-expire-time'.
+If `url-standalone-mode' is non-nil, cached items never expire."
+  (if url-standalone-mode
+      (not (file-exists-p (url-cache-create-filename url)))
+    (let ((cache-time (url-is-cached url)))
+      (or (not cache-time)
+         (time-less-p
+          (time-add
+           cache-time
+           (seconds-to-time (or expire-time url-cache-expire-time)))
+          (current-time))))))
 
 (provide 'url-cache)