def make_demand_func(query):
func = N.get_query_demand_func_name(query.name)
uset = N.get_query_demand_set_name(query.name)
maxsize = query.demand_set_maxsize
if maxsize is None:
code = L.Parser.ps('''
def _FUNC(_elem):
if _elem not in _U:
_U.reladd(_elem)
''',
subst={
'_FUNC': func,
'_U': uset
})
elif maxsize == 1:
code = L.Parser.ps('''
def _FUNC(_elem):
if _elem not in _U:
_U.relclear()
_U.reladd(_elem)
''',
subst={
'_FUNC': func,
'_U': uset
})
elif not isinstance(maxsize, int) or maxsize <= 0:
raise L.ProgramError('Invalid value for demand_set_maxsize')
else:
code = L.Parser.ps('''
def _FUNC(_elem):
if _elem not in _U:
while len(_U) >= _MAXSIZE:
_stale = _U.peek()
_U.relremove(_stale)
_U.reladd(_elem)
''',
subst={
'_FUNC': func,
'_U': uset,
'_MAXSIZE': L.Num(maxsize)
})
return code
def visit_RelUpdate(self, node):
if isinstance(node.op, L.SetAdd):
is_add = True
elif isinstance(node.op, L.SetRemove):
is_add = False
else:
return
rel = node.rel
elem = L.Name(node.elem)
if N.is_M(rel):
set_ = L.Subscript(elem, L.Num(0))
value = L.Subscript(elem, L.Num(1))
code = (L.SetUpdate(set_, node.op, value),)
elif N.is_F(rel):
attr = N.get_F(rel)
obj = L.Subscript(elem, L.Num(0))
value = L.Subscript(elem, L.Num(1))
if is_add:
code = (L.AttrAssign(obj, attr, value),)
else:
code = (L.AttrDelete(obj, attr),)
elif N.is_MAP(rel):
map = L.Subscript(elem, L.Num(0))
key = L.Subscript(elem, L.Num(1))
value = L.Subscript(elem, L.Num(2))
if is_add:
code = (L.DictAssign(map, key, value),)
else:
code = (L.DictDelete(map, key),)
else:
code = node
return code
def make_projection_expr(self, state):
return L.Subscript(state, L.Num(0))
def make_update_state_code(self, prefix, state, op, value):
opcls = {L.SetAdd: L.Add, L.SetRemove: L.Sub}[op.__class__]
by = {'count': L.Num(1), 'sum': L.Name(value)}[self.kind]
return (L.Assign(state, L.BinOp(L.Name(state), opcls(), by)), )
