import time import random from zope.interface import implements from zope.interface import classProvides from zope.interface import Interface from zope.component import adapts from zope.component import getMultiAdapter from zope.publisher.interfaces.http import IHTTPRequest from plone.caching.interfaces import ICachingOperation from plone.caching.interfaces import ICachingOperationType from plone.caching.utils import lookupOptions from plone.app.caching.operations.utils import setCacheHeaders from plone.app.caching.operations.utils import doNotCache from plone.app.caching.operations.utils import cacheInRAM from plone.app.caching.operations.utils import cacheStop from plone.app.caching.operations.utils import cachedResponse from plone.app.caching.operations.utils import notModified from plone.app.caching.operations.utils import getETagAnnotation from plone.app.caching.operations.utils import getContext from plone.app.caching.operations.utils import getLastModifiedAnnotation from plone.app.caching.operations.utils import fetchFromRAMCache from plone.app.caching.operations.utils import isModified from plone.app.caching.operations.utils import visibleToRole from plone.app.caching.interfaces import _ try: from Products.ResourceRegistries.interfaces import ICookedFile from Products.ResourceRegistries.interfaces import IResourceRegistry HAVE_RESOURCE_REGISTRIES = True except ImportError: HAVE_RESOURCE_REGISTRIES = False class BaseCaching(object): """A generic caching operation class that can do pretty much all the usual caching operations based on options settings. For UI simplicity, it might be easier to subclass this in your custom operations to set a few default operations. Generic options (Default value for each is None): ``maxage`` is the maximum age of the cached item, in seconds.. ``smaxage`` is the maximum age of the cached item in proxies, in seconds. ``etags'' is a list of etag components to use when constructing an etag. ``lastModified`` is a boolean indicating whether to set a Last-Modified header and turn on 304 responses. ``ramCache`` is a boolean indicating whether to turn on RAM caching for this item. Etags are only required if the URL is not specific enough to ensure uniqueness. ``vary`` is a string to add as a Vary header value in the response. """ implements(ICachingOperation) adapts(Interface, IHTTPRequest) # Type metadata classProvides(ICachingOperationType) title = _(u"Generic caching") description = _(u"Through this operation, all standard caching functions " u"can be performed via various combinations of the optional " u"parameter settings. For most cases, it's probably easier " u"to use one of the other simpler operations (Strong caching, " u"Moderate caching, Weak caching, or No caching).") prefix = 'plone.app.caching.baseCaching' options = ('maxage','smaxage','etags','lastModified','ramCache', 'vary', 'anonOnly') # Default option values maxage = smaxage = etags = vary = None lastModified = ramCache = anonOnly = False def __init__(self, published, request): self.published = published self.request = request def interceptResponse(self, rulename, response, class_=None): options = lookupOptions(class_ or self.__class__, rulename) etags = options.get('etags') or self.etags anonOnly = options.get('anonOnly', self.anonOnly) ramCache = options.get('ramCache', self.ramCache) lastModified = options.get('lastModified', self.lastModified) # Add the ``anonymousOrRandom`` etag if we are anonymous only if anonOnly: if etags is None: etags = ['anonymousOrRandom'] elif 'anonymousOrRandom' not in etags: etags = tuple(etags) + ('anonymousOrRandom',) etag = getETagAnnotation(self.published, self.request, keys=etags) lastModified = getLastModifiedAnnotation(self.published, self.request, lastModified=lastModified) # Check for cache stop request variables if cacheStop(self.request, rulename): return None # Check if this should be a 304 response if not isModified(self.request, etag=etag, lastModified=lastModified): return notModified(self.published, self.request, response, etag=etag, lastModified=lastModified) # Check if this is in the ram cache if ramCache: context = getContext(self.published) portal_state = getMultiAdapter((context, self.request), name=u'plone_portal_state') if portal_state.anonymous(): cached = fetchFromRAMCache(self.request, etag=etag, lastModified=lastModified) if cached is not None: return cachedResponse(self.published, self.request, response, *cached) return None def modifyResponse(self, rulename, response, class_=None): options = lookupOptions(class_ or self.__class__, rulename) maxage = options.get('maxage', self.maxage) smaxage = options.get('smaxage', self.smaxage) etags = options.get('etags') or self.etags anonOnly = options.get('anonOnly', self.anonOnly) ramCache = options.get('ramCache', self.ramCache) vary = options.get('vary', self.vary) # Add the ``anonymousOrRandom`` etag if we are anonymous only if anonOnly: if etags is None: etags = ['anonymousOrRandom'] elif 'anonymousOrRandom' not in etags: etags = tuple(etags) + ('anonymousOrRandom',) etag = getETagAnnotation(self.published, self.request, etags) lastModified = getLastModifiedAnnotation(self.published, self.request, options['lastModified']) # Check for cache stop request variables if cacheStop(self.request, rulename): # only stop with etags if configured if etags: etag = "%s%d" % (time.time(), random.randint(0, 1000)) return setCacheHeaders(self.published, self.request, response, etag=etag) # XXX: should there be an else here? Last modified works without extra headers. # Are there other config options? # Do the maxage/smaxage settings allow for proxy caching? proxyCache = smaxage or (maxage and smaxage is None) # Check if the content can be cached in shared caches public = True if ramCache or proxyCache: if etags is not None: if 'userid' in etags or 'anonymousOrRandom' in etags or 'roles' in etags: context = getContext(self.published) portal_state = getMultiAdapter((context, self.request), name=u'plone_portal_state') public = portal_state.anonymous() public = public and visibleToRole(self.published, role='Anonymous') if proxyCache and not public: # This is private so keep it out of both shared and browser caches maxage = smaxage = 0 setCacheHeaders(self.published, self.request, response, maxage=maxage, smaxage=smaxage, etag=etag, lastModified=lastModified, vary=vary) if ramCache and public: cacheInRAM(self.published, self.request, response, etag=etag, lastModified=lastModified) class WeakCaching(BaseCaching): """Weak caching operation. A subclass of the generic BaseCaching operation to help make the UI approachable by mortals """ # Type metadata classProvides(ICachingOperationType) title = _(u"Weak caching") description = _(u"Cache in browser but expire immediately and enable 304 " u"responses on subsequent requests. 304's require configuration " u"of the 'Last-modified' and/or 'ETags' settings. If Last-Modified " u"header is insufficient to ensure freshness, turn on ETag " u"checking by listing each ETag components that should be used to " u"to construct the ETag header. " u"To also cache public responses in Zope memory, set 'RAM cache' to True. ") prefix = 'plone.app.caching.weakCaching' sort = 3 # Configurable options options = ('etags','lastModified','ramCache','vary', 'anonOnly') # Default option values maxage = 0 smaxage = etags = vary = None lastModified = ramCache = anonOnly = False class ModerateCaching(BaseCaching): """Moderate caching operation. A subclass of the generic BaseCaching operation to help make the UI approachable by mortals """ # Type metadata classProvides(ICachingOperationType) title = _(u"Moderate caching") description = _(u"Cache in browser but expire immediately (same as 'weak caching'), " u"and cache in proxy (default: 24 hrs). " u"Use a purgable caching reverse proxy for best results. " u"Caution: If proxy cannot be purged, or cannot be configured " u"to remove the 's-maxage' token from the response, then stale " u"responses might be seen until the cached entry expires. ") prefix = 'plone.app.caching.moderateCaching' sort = 2 # Configurable options options = ('smaxage','etags','lastModified','ramCache','vary', 'anonOnly') # Default option values maxage = 0 smaxage = 86400 etags = vary = None lastModified = ramCache = anonOnly = False class StrongCaching(BaseCaching): """Strong caching operation. A subclass of the generic BaseCaching operation to help make the UI approachable by mortals """ # Type metadata classProvides(ICachingOperationType) title = _(u"Strong caching") description = _(u"Cache in browser and proxy (default: 24 hrs). " u"Caution: Only use for stable resources " u"that never change without changing their URL, or resources " u"for which temporary staleness is not critical.") prefix = 'plone.app.caching.strongCaching' sort = 1 # Configurable options options = ('maxage','smaxage','etags','lastModified','ramCache','vary', 'anonOnly') # Default option values maxage = 86400 smaxage = etags = vary = None lastModified = ramCache = anonOnly = False if HAVE_RESOURCE_REGISTRIES: class ResourceRegistriesCaching(StrongCaching): """Override for StrongCaching which checks ResourceRegistries cacheability """ adapts(ICookedFile, IHTTPRequest) def interceptResponse(self, rulename, response): return super(ResourceRegistriesCaching, self).interceptResponse(rulename, response, class_=StrongCaching) def modifyResponse(self, rulename, response): registry = getContext(self.published, IResourceRegistry) if registry is not None: if registry.getDebugMode() or not registry.isCacheable(self.published.__name__): doNotCache(self.published, self.request, response) return super(ResourceRegistriesCaching, self).modifyResponse(rulename, response, class_=StrongCaching) class NoCaching(object): """A caching operation that tries to keep the response out of all caches. """ implements(ICachingOperation) adapts(Interface, IHTTPRequest) # Type metadata classProvides(ICachingOperationType) title = _(u"No caching") description = _(u"Use this operation to keep the response " u"out of all caches.") prefix = 'plone.app.caching.noCaching' sort = 4 options = () def __init__(self, published, request): self.published = published self.request = request def interceptResponse(self, rulename, response): return None def modifyResponse(self, rulename, response): doNotCache(self.published, self.request, response)