Info Catalog url: General Facilities url: Proxies

url: Disk Caching

 
 5.1 Disk Caching
 ================
 
 The disk cache stores retrieved documents locally, whence they can be
 retrieved more quickly.  When requesting a URL that is in the cache, the
 library checks to see if the page has changed since it was last
 retrieved from the remote machine.  If not, the local copy is used,
 saving the transmission over the network.  Currently the cache isn’t
 cleared automatically.
 
  -- User Option: url-automatic-caching
      Setting this variable non-‘nil’ causes documents to be cached
      automatically.
 
  -- User Option: url-cache-directory
      This variable specifies the directory to store the cache files.  It
      defaults to sub-directory ‘cache’ of ‘url-configuration-directory’.
 
  -- User Option: url-cache-creation-function
      The cache relies on a scheme for mapping URLs to files in the
      cache.  This variable names a function which sets the type of cache
      to use.  It takes a URL as argument and returns the absolute file
      name of the corresponding cache file.  The two supplied
      possibilities are ‘url-cache-create-filename-using-md5’ and
      ‘url-cache-create-filename-human-readable’.
 
  -- Function: url-cache-create-filename-using-md5 url
      Creates a cache file name from URL using MD5 hashing.  This is
      creates entries with very few cache collisions and is fast.
           (url-cache-create-filename-using-md5 "http://www.example.com/foo/bar")
             ⇒ "/home/fx/.url/cache/fx/http/com/example/www/b8a35774ad20db71c7c3409a5410e74f"
 
  -- Function: url-cache-create-filename-human-readable url
      Creates a cache file name from URL more obviously connected to URL
      than for ‘url-cache-create-filename-using-md5’, but more likely to
      conflict with other files.
           (url-cache-create-filename-human-readable "http://www.example.com/foo/bar")
             ⇒ "/home/fx/.url/cache/fx/http/com/example/www/foo/bar"
 
  -- Function: url-cache-expired
      This function returns non-‘nil’ if a cache entry has expired (or is
      absent).  The arguments are a URL and optional expiration delay in
      seconds (default URL-CACHE-EXPIRE-TIME).
 
  -- User Option: url-cache-expire-time
      This variable is the default number of seconds to use for the
      expire-time argument of the function ‘url-cache-expired’.
 
  -- Function: url-fetch-from-cache
      This function takes a URL as its argument and returns a buffer
      containing the data cached for that URL.
 

Info Catalog url: General Facilities url: Proxies