EEA Cache

Introduction

This package combines the features from lovely.memcached and plone.memoize.ram. It provides a decorator and utility for Memcaches at EEA. The decorator allows you set dependencies known by eea.cache

Contents

Main features

1. Extends and overrides plone.memoize cache adapters to work with memcache
2. Provides an extended @cache decorator that supports:
   • cache lifetime override per method
   • dependencies string in order to bulk invalidate cache
   • auto-invalidation of cache when ObjectModifiedEvent is triggered
3. Possibility to manually invalidate cache via URL.

Install

• Add eea.cache to your eggs and zcml section in your buildout and re-run buildout:

  eggs =
    ...
    eea.cache
  
  zcml =
    ...
    eea.cache
    eea.cache-overrides
  

• You can download a sample buildout from

• Install eea.cache within Site Setup > Add-ons

• Start memcache:

  $ bin/memcached start
  

Dependencies

• python-memcached
• pylibmc (optional, for better performance)
• plone.memoize
• plone.uuid

Source code

Latest source code (Zope 2 compatible):

• Plone Collective on Github
• EEA on Github

Cache decorator

>>> def key(method, self):
...     return method.__name__

>>> from eea.cache import cache
>>> @cache(key, dependencies=["frontpage"])
... def myMethod(num):
...     return num*num

Lets clear any running memcache:

>>> from eea.cache.event import InvalidateMemCacheEvent
>>> from zope.event import notify
>>> notify(InvalidateMemCacheEvent(raw=True, dependencies=['frontpage']))

Our myMethod will now be cached with the key returned from the method 'key' and with dependency 'frontpage':

>>> myMethod(2)
4
>>> myMethod(3)
4

>>> notify(InvalidateMemCacheEvent(raw=True, dependencies=['frontpage']))
>>> myMethod(3)
9

Cache lifetime

By default your content is cached in memcache for one hour (3600 seconds). You can change this by adding an int property within: ZMI > portal_properties > site_properties called memcached_defaultLifetime and set it's value to 86400 (one day) for example.

Cache lifetime override per key

Starting with eea.cache 5.1 you can also pass a lifetime key with the duration in seconds which will override the defaultLifetime either given from the portal property or the default one from lovely.memcached of 3600 seconds:

ex: in order to cache the result only for 4 minutes
>>> @cache(key, dependencies=["frontpage"], lifetime=240)
... def myMethod(num):
...     return num*num

Invalidate cache

If you use cache decorator for BrowserView methods or directly on Zope objects methods cache will be automatically invalidated when object is modified (ObjectModifiedEvent is triggered):

>>> from Products.Five.browser import BrowserView

>>> class XXX(BrowserView):
...     @cache(key)
...     def title(self):
...         return self.context.title_or_id()

You can disable auto invalidation by providing the auto_invalidate param to @cache decorator:

>>> @cache(key, auto_invalidate=False)
... def title(self):
...     return self.context.title_or_id()

memcache.invalidate

In order to manually invalidate memcached cache per object this package provides a browser view called memcache.invalidate. It will invalidate all memcached methods associated with current object's UID:

http://localhost:2020/Plone/front-page/memcache.invalidate

You can also manually invalidate related items and back references:

http://localhost:2020/Plone/front-page/memcache.invalidate/relatedItems

http://localhost:2020/Plone/front-page/memcache.invalidate/backRefs

By default this method can be called by users with these roles:

• Editor
• CommonEditor
• Owner
• Manager

varnish.invalidate

In order to manually invalidate memcached cache per object this package provides a browser view called varnish.invalidate. It will invalidate all memcached methods associated with current object's UID:

http://localhost:2020/Plone/front-page/varnish.invalidate

You can also manually invalidate related items and back references:

http://localhost:2020/Plone/front-page/varnish.invalidate/relatedItems

http://localhost:2020/Plone/front-page/varnish.invalidate/backRefs

By default this method can be called by users with these roles:

• Editor
• CommonEditor
• Owner
• Manager

cache.invalidate

In order to manually invalidate cache (memcached and varnish) per object this package provides a browser view called cache.invalidate. It will call memcache.invalidate and varnish.invalidate:

http://localhost:2020/Plone/front-page/cache.invalidate

You can also manually invalidate related items and back references:

http://localhost:2020/Plone/front-page/cache.invalidate/relatedItems

http://localhost:2020/Plone/front-page/cache.invalidate/backRefs

By default this method can be called by users with these roles:

• Editor
• CommonEditor
• Owner
• Manager

cache.settings

There is also a Cache Tab per object where you can manually select which cache to invalidate. By default, you can invalidate memcache and varnish. You also have the possibility to invalidate memcache and/or varnish for related items and also fo back references.

This form can be extended with more options. For a more detailed example see eea.pdf

configure.zcml:

behavior.py:

# Model
class IExtraSettings(model.Schema):
    """ Extra settings
    """
    pdf = schema.Bool(
        title=_(u"PDF"),
        description=_(u"Invalidate latest generated PDF file"),
        required=False,
        default=False
    )


# Behaviour
class ExtraBehavior(object):
    implements(IExtraSettings)
    adapts(IPDFAware)

    def __init__(self, context):
        self.context = context

    @property
    def pdf(self):
        """ PDF
        """
        return False

    @pdf.setter
    def pdf(self, value):
        """ Invalidate last generated PDF?
        """
        if not value:
            return

        removePdfFiles()

# Form
class ExtraSettings(extensible.FormExtender):
    adapts(IPDFAware, ILayer, SettingsForm)

    def __init__(self, context, request, form):
        self.context = context
        self.request = request
        self.form = form

    def update(self):
        """ Extend form
        """
        self.add(IExtraSettings, prefix="extra")
        self.move('pdf', after='varnish', prefix='extra')

Copyright and license

The Initial Owner of the Original Code is European Environment Agency (EEA). All Rights Reserved.

The eea.cache (the Original Code) is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

More details under docs/License.txt

Funding and project management

EEA - European Environment Agency (EU)

Changelog

9.5 - (2021-12-16)

• Change: Plone 6 / pip install ready. Drop includeDependencies [avoinea]

9.4 - (2020-03-10)

• Bug fix: avoid error when cache key contains utf-8 characters [ichim-dvaid refs #113458]

9.3 - (2020-03-04)

• Bug fix: Removed hard dependency on plone.app.caching: missing VARNISH.__name__ [avoinea]

9.2 - (2019-12-13)

• Bug fix: Fix the uninstall profile [avoinea]

9.1 - (2019-11-21)

• Feature: Made all Dexterity content cache aware [avoinea refs #110155]
• Feature: Added support for Python 3 and Plone 5.2 [alecghica refs #110155]

9.0 - (2019-06-06)

• Change: Cache decorator no longer caches empty results [ichim-david refs #104467]
• Feature: Cache decorator now has cache_empty parameter if it's set will still cache empty results [ichim-david refs #104467]

8.5 - (2019-01-28)

• Jenkins: Add sonarqube step [avoinea refs #101552]
• Change: updated URLs pointing to eea.europa.eu with [alecghica refs #95849]

8.4 - (2018-06-13)

• Bug fix: lambda takes no arguments (1 given) [avoinea]

8.3 - (2018-06-06)

• Bug fix: Fix relatedItems cache invalidation [avoinea refs #95891]

8.2 - (2018-05-24)

• Bug fix: Speed-up cache invalidation for backward-references [avoinea refs #95020]
• Feature: replaced invalidate_cache method with a method that use eea.cache [alecghica refs #95020]
• Feature: "Refresh this page" method redirect you back to the original context [alecghica refs #95020]
• Feature: cache.settings if called in a context of a default view it will also invalidate its parent [alecghica refs #95020]
• Bug fix: fixed case under all invalidate methods when a broken relations is present and None is found instead of an object [alecghica refs #95020]

8.1 - (2017-12-12)

• Change: Replace eeacms/zptlint with eeacms/plone-test:4 zptlint [avoinea refs #90415]

8.0 - (2017-11-07)

• Change: Remove Sphinx generated documentation [petchesi-iulian refs #88212]

7.9 - (2017-05-22)

• Change: fixed PyLint warnings and errors [valipod refs #84949]

7.8 - (2017-05-15)

• Change: fixed PyLint warnings and errors [eduard-fironda refs #84949]

7.7 - (2017-04-24)

• Change: updated package information [eduard-fironda]

7.6 - (2016-05-19)

• Bug fix: Fix pylint warnings [chiridra refs #71940]

7.5 - (2015-08-18)

• Change: Auto-include zcml within plone context in order to make this package work without having to add it within buildout zcml directive. [avoinea]
• Feature: Implemented support for pylibmc [razvanchitu refs #27571]

7.4 - (2015-03-17)

• Change: Switched to curl in the jenkins build install script [olimpiurob refs #22402]
• Change: Changed fetch url for jenkins build install script to the install script from the main EEA CPB repository [olimpiurob refs #22402]

7.3 - (2014-12-23)

• Bug fix: fixed libevent download made by the buildout [ghicaale refs #21453]

7.2 - (2014-11-20)

• Change: Added InvalidateEverything event to be able to invalidate memcache and varnish instead of adding subscribers on ObjectModifiedEvent [voineali refs #21852, #21850, #21851]
• Change: Migrate cache invalidation form to plone.z3cform in order to easily extend it outside this package [voineali refs #21630]

7.1 - (2014-10-01)

• Feature: invalidate Memcache now appear on cache form as one of the options. [ghicaale refs #21143]
• Feature: created handler to invalidate only Varnish. [ghicaale refs #21143]
• Feature: improved result messages. [ghicaale refs #21143]

7.0 - (2014-08-27)

• Upgrade step: Within "Plone > Site setup > Add-ons" install EEA Cache [voineali refs #20678]
• Pre-upgrade step: Also add eea.cache within buildout zcml directive before eea.cache-overrides [voineali refs #20678]
• Feature: Added a browser view called cache.invalidate that allows editors to manually invalidate cache (including varnish and memcache). It also supports invalidation for related-items and back-references [voineali refs #20678]
• Feature: Added a browser view called memcache.invalidate that allows users to manually invalidate memcache. It also supports invalidation of relatedItems and back-references memcache [voineali refs #20678]
• Change: Auto-invalidate all cache associated with current object's UID when ObjectModifiedEvent is triggered [voineali refs #20678]

6.3 - (2014-01-21)

• Bug fix: removed wrongly added blockquotes within README.rst [ichim-david refs #18064]
• Feature: adding Sphinx-generated documentation in Page Template format [batradav refs #9502]

6.2 - (2013-10-04)

• Change: updated zope imports with the versions that require minimum Plone 4.1 for eea.cache [ichimdav refs #15651]

6.1 - (2013-06-17)

• Cleanup: Use logger.debug instead of logger.info for debug messages [avoinea]

6.0 - (2013-05-20)

• Feature: Removed lovely.memcached dependency [voineali refs #14343]

5.1 - (2013-02-04)

• Feature: added information for contributors [ciobabog refs #13892]
• Feature: added ability to pass a lifetime key to the cache decorator in order to cache it for a determined period different from the default lifetime [ichimdav #13677]
• Upgrade step: (optional) Within ZMI > portal_properties > site_properties add an int property called memcached_defaultLifetime and set it's value to 86400 (one day) or any value that fits your needs.
• Feature: Ability to set memcached default lifetime, which by now was hardcoded to one hour (3600 seconds) [voineali refs #13677]

5.0 - (2012-10-08)

• Change: Updated README and egg's metadata [voineali refs #5434]

4.3 - (2012-07-13)

• Bug fix: fixed markup of HISTORY.txt file [ciobabog refs #5231]

4.2 - (2012-02-06)

> - no changes

4.0 - (2011-11-07)

• Feature: Plone 4.x compatible release [ghicaale #4309]

0.3 - (2010-11-22)

• Bug fix: fixed tests namespace in order to be used within hudson [voineali #3821]

0.2 - (2010-11-10)

• Bug fix: added fake memcache client in order to fix broken doctests [voineali]

0.1 - (2009-11-10)

• Initial release