def test_direct_entries_access(ctx):
from melkman.db.bucket import NewsBucket, NewsItemRef
# if you add something to bucket.entries directly rather than going
# through the interface, make sure it's there after saving (i.e. NewsBucket
# is properly observing changes to the underlying nldict)
bucket = NewsBucket.create(ctx)
assert len(bucket.entries) == 0
item1 = NewsItemRef.create_from_info(ctx, bucket.id, item_id=random_id())
item2 = NewsItemRef.create_from_info(ctx, bucket.id, item_id=random_id())
bucket.entries[item1.item_id] = item1
bucket.entries[item2.item_id] = item2
assert len(bucket.entries) == 2
assert bucket.has_news_item(item1)
assert bucket.has_news_item(item2)
bucket.save()
bucket.reload()
assert len(bucket.entries) == 2
assert bucket.has_news_item(item1)
assert bucket.has_news_item(item2)
# directly changing the maxlen of the underlying nldict instead of using
# NewsBucket.set_maxlen is *not* supported:
bucket.entries.maxlen = 1 # causes items to be deleted in memory:
assert len(bucket.entries) == 1
# but the document's maxlen field is not updated:
assert bucket.maxlen is None
# so after re-retrieving the document the nldict's maxlen is the old value
bucket.reload()
assert bucket.entries.maxlen is None
assert len(bucket.entries) == 2 # and the bucket still has two items
# if we save after changing the nldict's maxlen...
bucket.entries.maxlen = 1 # items deleted in memory
assert len(bucket.entries) == 1
bucket.save()
# ...items are now deleted from persistent storage too
bucket.reload()
assert len(bucket.entries) == 1
# but the maxlen field on the document was still never set
assert bucket.maxlen == None
# add back both items since one of them was discarded
bucket.entries.update({item1.item_id: item1, item2.item_id: item2})
bucket.save()
bucket.reload()
assert len(bucket.entries) == 2
# if we set the maxlen field on the bucket rather than using set_maxlen...
bucket.maxlen = 1
# maxlen changes in the document but the underlying nldict is not updated:
assert len(bucket.entries) == 2
# ...until *after* saving:
bucket.save()
bucket.reload()
assert len(bucket.entries) == 1
def test_bucket_maxlen(ctx):
"""
Test that bucket with maxlen behaves as expected
"""
from melkman.db.bucket import NewsBucket, NewsItemRef, SORTKEY
from datetime import datetime, timedelta
from operator import attrgetter
# add 10 items spaced an hour apart to a bucket of max-length 3:
maxlen = 3
sortkey = SORTKEY # for now this is hardcoded in melkman.db.bucket
bucket = NewsBucket.create(ctx, maxlen=maxlen)
assert bucket.maxlen == maxlen
items = []
timestamp = datetime.utcnow()
for i in xrange(10):
item = NewsItemRef.create_from_info(ctx, bucket.id,
item_id=random_id(),
timestamp=timestamp - timedelta(hours=i),
)
items.append(item)
bucket.add_news_item(item)
# make sure the bucket has only the maxlen latest items
# before and after saving:
idgetter = attrgetter('item_id')
sorteditemsids = map(idgetter, sorted(items, key=sortkey))
def ids_by_timestamp(entries):
return map(idgetter, sorted(entries.values(), key=sortkey))
def check_before_and_after_save(bucket):
bucketlen = len(bucket.entries)
if bucket.maxlen is not None:
assert bucketlen <= bucket.maxlen
assert ids_by_timestamp(bucket.entries) == sorteditemsids[-bucketlen:]
bucket.save()
bucket.reload()
assert ids_by_timestamp(bucket.entries) == sorteditemsids[-bucketlen:]
return bucket
bucket = check_before_and_after_save(bucket)
# decrease maxlen and make sure bucket.entries remains consistent:
maxlen -= 1
bucket.set_maxlen(maxlen)
bucket = check_before_and_after_save(bucket)
# now increase maxlen so that the bucket is under capacity and check consistency:
maxlen += 2
bucket.set_maxlen(maxlen)
bucket = check_before_and_after_save(bucket)
# fill to capacity and check that the new maxlen is maintained:
for i in items:
bucket.add_news_item(i)
bucket = check_before_and_after_save(bucket)
# now set the maxlen to None and make sure it becomes an unbounded bucket:
maxlen = None
bucket.set_maxlen(maxlen)
for i in items:
bucket.add_news_item(i)
bucket = check_before_and_after_save(bucket)
