def test_refusal_to_create_expensive_feed(self):
facets = Facets.default()
pagination = Pagination.default()
lane = Lane(self._db, "My Lane", languages=['eng', 'chi'])
args = (self._db, lane, CachedFeed.PAGE_TYPE, facets, pagination, None)
# If we ask for a group feed that will be cached forever, and it's
# not around, we'll get a page feed instead.
feed, fresh = CachedFeed.fetch(*args,
max_age=Configuration.CACHE_FOREVER)
eq_(CachedFeed.PAGE_TYPE, feed.type)
# If we ask for the same feed, but we don't say it must be cached
# forever, it'll be created.
feed, fresh = CachedFeed.fetch(*args, max_age=0)
# Or if we explicitly demand that the feed be created, it will
# be created.
feed, fresh = CachedFeed.fetch(*args,
force_refresh=True,
max_age=Configuration.CACHE_FOREVER)
feed.update("Cache this forever!")
# Once the feed has content associated with it, we can ask for
# it in cached-forever mode and no longer get the exception.
feed, fresh = CachedFeed.fetch(*args,
max_age=Configuration.CACHE_FOREVER)
eq_("Cache this forever!", feed.content)
def test_lifecycle(self):
facets = Facets.default()
pagination = Pagination.default()
lane = Lane(self._db, "My Lane", languages=['eng', 'chi'])
# Fetch a cached feed from the database--it's empty.
args = (self._db, lane, CachedFeed.PAGE_TYPE, facets, pagination, None)
feed, fresh = CachedFeed.fetch(*args, max_age=0)
eq_(False, fresh)
eq_(None, feed.content)
eq_(pagination.query_string, feed.pagination)
eq_(facets.query_string, feed.facets)
eq_(lane.name, feed.lane_name)
eq_('eng,chi', feed.languages)
# Update the content
feed.update("The content")
self._db.commit()
# Fetch it again.
feed, fresh = CachedFeed.fetch(*args, max_age=0)
# Now it's cached! But not fresh, because max_age is zero
eq_("The content", feed.content)
eq_(False, fresh)
# Lower our standards, and it's fresh!
feed, fresh = CachedFeed.fetch(*args, max_age=1000)
eq_("The content", feed.content)
eq_(True, fresh)
def test_lifecycle_with_worklist(self):
facets = Facets.default(self._default_library)
pagination = Pagination.default()
lane = WorkList()
lane.initialize(self._default_library)
# Fetch a cached feed from the database--it's empty.
args = (self._db, lane, CachedFeed.PAGE_TYPE, facets, pagination, None)
feed, fresh = CachedFeed.fetch(*args, max_age=0)
eq_(False, fresh)
eq_(None, feed.content)
eq_(pagination.query_string, feed.pagination)
eq_(facets.query_string, feed.facets)
eq_(None, feed.lane_id)
# Update the content
feed.update(self._db, u"The content")
self._db.commit()
# Fetch it again.
feed, fresh = CachedFeed.fetch(*args, max_age=0)
# Now it's cached! But not fresh, because max_age is zero
eq_("The content", feed.content)
eq_(False, fresh)
# Lower our standards, and it's fresh!
feed, fresh = CachedFeed.fetch(*args, max_age=1000)
eq_("The content", feed.content)
eq_(True, fresh)
def test_fetch_ignores_feeds_without_content(self):
facets = Facets.default(self._default_library)
pagination = Pagination.default()
lane = self._lane(u"My Lane", languages=['eng', 'chi'])
# Create a feed without content (i.e. don't update it)
contentless_feed = get_one_or_create(
self._db,
CachedFeed,
lane_id=lane.id,
type=CachedFeed.PAGE_TYPE,
facets=unicode(facets.query_string),
pagination=unicode(pagination.query_string))[0]
# It's not returned because it hasn't been updated.
args = (self._db, lane, CachedFeed.PAGE_TYPE, facets, pagination, None)
feed, fresh = CachedFeed.fetch(*args)
eq_(True, feed != contentless_feed)
eq_(False, fresh)
# But if the feed is updated, we get it back.
feed.update(self._db, u"Just feedy things")
result, fresh = CachedFeed.fetch(*args)
eq_(True, fresh)
eq_(feed, result)
def page(cls, _db, title, url, lane, annotator=None,
facets=None, pagination=None,
cache_type=None, force_refresh=False,
use_materialized_works=True
):
"""Create a feed representing one page of works from a given lane."""
facets = facets or Facets.default()
pagination = pagination or Pagination.default()
cache_type = cache_type or CachedFeed.PAGE_TYPE
# Find or create a CachedFeed.
cached, usable = CachedFeed.fetch(
_db,
lane=lane,
type=cache_type,
facets=facets,
pagination=pagination,
annotator=annotator,
force_refresh=force_refresh
)
if usable:
return cached
if use_materialized_works:
works_q = lane.materialized_works(facets, pagination)
else:
works_q = lane.works(facets, pagination)
if not works_q:
works = []
else:
works = works_q.all()
feed = cls(_db, title, url, works, annotator)
# Add URLs to change faceted views of the collection.
for args in cls.facet_links(annotator, facets):
OPDSFeed.add_link_to_feed(feed=feed.feed, **args)
if len(works) > 0:
# There are works in this list. Add a 'next' link.
OPDSFeed.add_link_to_feed(feed=feed.feed, rel="next", href=annotator.feed_url(lane, facets, pagination.next_page))
if pagination.offset > 0:
OPDSFeed.add_link_to_feed(feed=feed.feed, rel="first", href=annotator.feed_url(lane, facets, pagination.first_page))
previous_page = pagination.previous_page
if previous_page:
OPDSFeed.add_link_to_feed(feed=feed.feed, rel="previous", href=annotator.feed_url(lane, facets, previous_page))
# Add "up" link and breadcrumbs
top_level_title = annotator.top_level_title() or "Collection Home"
visible_parent = lane.visible_parent()
if isinstance(visible_parent, Lane):
title = visible_parent.display_name
else:
title = top_level_title
if visible_parent:
up_uri = annotator.lane_url(visible_parent)
OPDSFeed.add_link_to_feed(feed=feed.feed, href=up_uri, rel="up", title=title)
feed.add_breadcrumbs(lane, annotator)
OPDSFeed.add_link_to_feed(feed=feed.feed, rel='start', href=annotator.default_lane_url(), title=top_level_title)
annotator.annotate_feed(feed, lane)
content = unicode(feed)
cached.update(content)
return cached
