def get_equijoin_key_values(condition):
# condition must be a *leaf* condition.
if getattr(condition, 'op', None) != Condition.Op.EQ:
return None
# Get properties being accessed by left and right side of the
# conditional.
left_properties = get_properties_accessed_by_value(condition.left)
right_properties = get_properties_accessed_by_value(
condition.right)
if not (left_properties and right_properties):
return None
# Only return getters if both sides of the conditional read from different
# sources. You can't use this optimization say if the condition is
# (left.x + right.y = 10)
# XXX: This isn't kosher for non-deterministic functions.
if (all(p.startswith('%s.' % left_alias) for p in left_properties)
and all(
p.startswith('%s.' % right_alias)
for p in right_properties)):
return {'left': condition.left, 'right': condition.right}
if (all(
p.startswith('%s.' % right_alias) for p in left_properties)
and all(
p.startswith('%s.' % left_alias)
for p in right_properties)):
return {'left': condition.right, 'right': condition.left}
return None
def get_equijoin_key_values(condition):
# condition must be a *leaf* condition.
if getattr(condition, 'op', None) != Condition.Op.EQ:
return None
# Get properties being accessed by left and right side of the
# conditional.
left_properties = get_properties_accessed_by_value(condition.left)
right_properties = get_properties_accessed_by_value(condition.right)
if not (left_properties and right_properties):
return None
# Only return getters if both sides of the conditional read from different
# streams. You can't use this optimization say if the condition is
# (left.x + right.y = 10)
# XXX: This isn't kosher for non-deterministic functions.
if (all(p.startswith('%s.' % left_alias) for p in left_properties) and
all(p.startswith('%s.' % right_alias) for p in right_properties)):
return {'left': condition.left, 'right': condition.right}
if (all(p.startswith('%s.' % right_alias) for p in left_properties) and
all(p.startswith('%s.' % left_alias) for p in right_properties)):
return {'left': condition.right, 'right': condition.left}
return None
def test_get_properties_accessed_by_value(self):
self.assertEqual(get_properties_accessed_by_value(Property('lolcat')),
['lolcat'])
self.assertEqual(get_properties_accessed_by_value(Constant(0)), [])
self.assertEqual(
get_properties_accessed_by_value(
Add([
Property('lolcat'),
Constant(1),
Add([Property('hello'), Constant(2)])
])), ['lolcat', 'hello'])
def test_get_properties_accessed_by_value(self):
self.assertEqual(
get_properties_accessed_by_value(Property('lolcat')),
['lolcat'])
self.assertEqual(get_properties_accessed_by_value(Constant(0)),
[])
self.assertEqual(
get_properties_accessed_by_value(
Add([Property('lolcat'),
Constant(1),
Add([Property('hello'), Constant(2)])])
),
['lolcat', 'hello'])
