Commit 4b687d01 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

[1.0.X] Fixed #6748 -- When printing the repr() of querysets, don't load or 

display more than 20 objects.

This means that accidentally executing HugeStoryArchive.objects.all() at the
interactive prompt (or in the debug template) won't try to load all 4,233,010
stories into memory and print them out. That would previously cause resource
starvation and other "interesting" crashes.

If you really, really want the previous behaviour (e.g. in a doctest that
prints more than 20 items), display "list(qs)" instead of just "qs".

Backport of r9202 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9205 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent 09d84c4d

django/db/models/query.py

+7 −1
Original line number Diff line number Diff line
@@ -15,6 +15,9 @@ from django.utils.datastructures import SortedDict 
CHUNK_SIZE = 100

ITER_CHUNK_SIZE = CHUNK_SIZE



# The maximum number of items to display in a QuerySet.__repr__

REPR_OUTPUT_SIZE = 20



# Pull into this namespace for backwards compatibility.

EmptyResultSet = sql.EmptyResultSet
@@ -141,7 +144,10 @@ class QuerySet(object): 
        return obj_dict



    def __repr__(self):

        return repr(list(self))

        data = list(self[:REPR_OUTPUT_SIZE + 1])

        if len(data) > REPR_OUTPUT_SIZE:

            data[-1] = "...(remaining elements truncated)..."

        return repr(data)



    def __len__(self):

        # Since __len__ is called quite frequently (for example, as part of

tests/regressiontests/queries/models.py

+1 −1
Original line number Diff line number Diff line
@@ -556,7 +556,7 @@ Bug #2076 
# automatically. Item normally requires a join with Note to do the default

# ordering, but that isn't needed here.

>>> qs = Item.objects.order_by('name')

>>> qs

>>> list(qs)

[<Item: four>, <Item: one>, <Item: three>, <Item: two>]

>>> len(qs.query.tables)

1