Function get

cherrypy/lib/caching.py:264–377

Try to obtain cached output. If fresh enough, raise HTTPError(304). If POST, PUT, or DELETE: * invalidates (deletes) any cached response for this resource * sets request.cached = False * sets request.cacheable = False else if a cached copy exists: * sets req

(invalid_methods=('POST', 'PUT', 'DELETE'), debug=False, **kwargs)

def get(invalid_methods=('POST', 'PUT', 'DELETE'), debug=False, **kwargs):
    """Try to obtain cached output. If fresh enough, raise HTTPError(304).

    If POST, PUT, or DELETE:
        * invalidates (deletes) any cached response for this resource
        * sets request.cached = False
        * sets request.cacheable = False

    else if a cached copy exists:
        * sets request.cached = True
        * sets request.cacheable = False
        * sets response.headers to the cached values
        * checks the cached Last-Modified response header against the
          current If-(Un)Modified-Since request headers; raises 304
          if necessary.
        * sets response.status and response.body to the cached values
        * returns True

    otherwise:
        * sets request.cached = False
        * sets request.cacheable = True
        * returns False
    """
    request = cherrypy.serving.request
    response = cherrypy.serving.response

    if not hasattr(cherrypy, '_cache'):
        # Make a process-wide Cache object.
        cherrypy._cache = kwargs.pop('cache_class', MemoryCache)()

        # Take all remaining kwargs and set them on the Cache object.
        for k, v in kwargs.items():
            setattr(cherrypy._cache, k, v)
        cherrypy._cache.debug = debug

    # POST, PUT, DELETE should invalidate (delete) the cached copy.
    # See http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.10.
    if request.method in invalid_methods:
        if debug:
            cherrypy.log('request.method %r in invalid_methods %r' %
                         (request.method, invalid_methods), 'TOOLS.CACHING')
        cherrypy._cache.delete()
        request.cached = False
        request.cacheable = False
        return False

    if 'no-cache' in [e.value for e in request.headers.elements('Pragma')]:
        request.cached = False
        request.cacheable = True
        return False

    cache_data = cherrypy._cache.get()
    request.cached = bool(cache_data)
    request.cacheable = not request.cached
    if request.cached:
        # Serve the cached copy.
        max_age = cherrypy._cache.delay
        for v in [e.value for e in request.headers.elements('Cache-Control')]: