def __init__(self): self.marker = Marker() self.constraints = [] self.variables = [] self.forced_constraint = None self.check_constraints = False self.unenforced_constraints = set() self.redetermined_variables = set() self.exec_roots = [] self.mark = None self.plan = None self._cycle = None
from unittest import TestCase
try:
from unittest.mock import MagicMock as Mock
except ImportError as e:
from mock import Mock
from skypyblue.models import *
from skypyblue.core import Mvine, Marker, ConstraintSystem
marker = Marker()
new_mark = marker.new_mark
class MVineTests(TestCase):
def setUp(self):
self.marker = marker
self.mvine = Mvine(self.marker)
self.constraint_system = ConstraintSystem()
def test_build_mvine(self):
v1, v2, v3 = self.constraint_system.create_variables(["v1", "v2", "v3"], [3, 4, 5])
method1 = Method(
[v1, v2],
[v3],
lambda v1, v2: (v1 + v2) / 2)
method2 = Method(
[v3, v2],
[v1],
lambda v3, v2: 2 * v3 - v2)
class ConstraintSystem:
def __init__(self):
self.marker = Marker()
self.constraints = []
self.variables = []
self.forced_constraint = None
self.check_constraints = False
self.unenforced_constraints = set()
self.redetermined_vars = set()
self.exec_roots = []
self.mark = None
self._cycle = None
def create_variables(self, names, initialValues):
assert len(names) == len(initialValues)
res = []
for i in range(len(names)):
res.append(Variable(names[i], initialValues[i], self))
return res
def change_variable_values(self, variables, values):
if len(variables) == 1:
values = values[0]
m = Method([], variables,
lambda: values)
cn = Constraint(
lambda x: True,
InternalStrength.FORCED,
variables,
[m], "set")
if self.forced_constraint is not None:
# logger.DEBUG("removed %s" %(self.forced_constraint))
self.remove_constraint(self.forced_constraint, skip = True)
# logger.DEBUG(", ".join([str(var.determined_by) for var in self.variables]))
self.forced_constraint = cn
self.add_constraint(cn)
def variable_changed(self, var):
self.change_variable_values([var], [var.get_value()])
def _check_constraints(self):
if self.check_constraints == False:
return
for constraint in self.constraints:
if not constraint.is_enforced():
continue
check = constraint.check_function(*[var.get_value() for var in constraint.variables])
if not check:
raise Exception("Constraint %s is not satisfied" % constraint)
def add_stay_constraint(self, variable, strength):
m = Method([], [variable], lambda: variable.get_value())
stay_constraint = Constraint(
lambda x: True,
strength,
[variable],
[m], "stay")
self.add_constraint(stay_constraint)
return stay_constraint
@fail_on_cycle
def add_constraint(self, constraint):
constraint.selected_method = None
constraint.mark = None
for variable in constraint.variables:
variable.add_constraint(constraint)
self.unenforced_constraints = set([constraint])
self.exec_roots = []
self.update_method_graph()
self.exec_from_roots()
self.constraints.append(constraint)
self._check_constraints()
@fail_on_cycle
def remove_constraint(self, constraint, skip = False):
for variable in constraint.variables:
variable.remove_constraint(constraint)
self.constraints.remove(constraint)
if constraint.is_enforced():
old_outputs = set(constraint.selected_method.outputs)
constraint.selected_method = None
self.exec_roots = []
for variable in old_outputs:
variable.determined_by = None
variable.walk_strength = Strength.WEAKEST
self.exec_roots.append(variable)
if skip:
return
self.propagate_walk_strength(old_outputs)
self.unenforced_constraints = set()
self.collect_unenforced(constraint.strength, True)
self.update_method_graph()
self.exec_from_roots()
self._check_constraints()
def update_method_graph(self):
while self.unenforced_constraints:
constraint = self.remove_strongest_constraint()
self.redetermined_vars.clear()
if not Mvine(self.marker).build(constraint, self.redetermined_vars):
continue
self.propagate_walk_strength(self.redetermined_vars.union([constraint]))
self.collect_unenforced(constraint.strength, False)
self.exec_roots.append(constraint)
for var in self.redetermined_vars:
if var.determined_by is None:
self.exec_roots.append(var)
# logger.DEBUG("exec_roots: %s" %self.exec_roots)
def remove_strongest_constraint(self):
cn = sorted(self.unenforced_constraints, key = lambda cn: cn.strength, reverse = True)[0]
self.unenforced_constraints.remove(cn)
return cn
# not used yet
# def weakest_constraint(self, constraints):
# return sorted(constraints, key = lambda cn: cn.strength)[0]
def propagate_walk_strength(self, roots):
self._new_mark()
for cn in self.pplan_add(roots):
for var in cn.selected_method.inputs:
if var.determined_by is not None and var.determined_by.mark == self.mark:
var.walk_strength = Strength.WEAKEST
self.compute_walkabout_strengths(cn)
cn.mark = None
def compute_walkabout_strengths(self, cn):
outs = cn.selected_method.outputs
for out_var in outs:
max_strengths = [self.max_out(mt, outs) for mt in cn.methods if out_var not in mt.outputs]
max_strengths.append(cn.strength)
out_var.walk_strength = min(max_strengths)
def max_out(self, mt, current_outputs):
return max([var.walk_strength for var in mt.outputs if var not in current_outputs])
def collect_unenforced(self, collection_strength, collect_equal_strength):
self._new_mark()
for var in self.redetermined_vars:
stack = [var]
while stack:
cur_var = stack.pop()
for cn in cur_var.constraints:
if cn == cur_var.determined_by or cn.mark == self.mark:
continue
cn.mark = self.mark
if cn.is_enforced():
stack.extend(cn.selected_method.outputs)
elif Strength.weaker(cn.strength, collection_strength) or \
(collect_equal_strength and (cn.strength == collection_strength)):
self.unenforced_constraints.add(cn)
def any_immediate_upstream_marked(self, cn):
for var in cn.selected_method.inputs:
if var.determined_by is not None and var.determined_by.mark == self.mark:
return True
return False
def immediate_marked_upstream(self, cn):
return [var.determined_by for var in cn.selected_method.inputs if var.determined_by is not None and var.determined_by.mark == self.mark]
def exec_pplan_create(self):
cn_pplan = []
var_pplan = []
for cn_or_var in self.exec_roots:
if isinstance(cn_or_var, Constraint):
cn = cn_or_var
cn.add_to_pplan(cn_pplan, self.mark)
elif isinstance(cn_or_var, Variable):
var = cn_or_var
if var.determined_by is None and not var.valid:
var.add_to_pplan(var_pplan, self.mark)
var.valid = True
pplan = cn_pplan + var_pplan
# logger.DEBUG("pplan:\t%s" %", ".join([str(cn) for cn in reversed(pplan)]))
# logger.DEBUG("marks:\t%s" %", ".join([str(cn.mark) for cn in reversed(pplan)]))
return pplan
def exec_from_roots(self):
self._new_mark()
for cn in reversed(self.exec_pplan_create()):
if cn.mark == self.mark:
if self.any_immediate_upstream_marked(cn):
self.exec_from_cycle(cn)
else:
cn.mark = None
self.execute_propagate_valid(cn)
def execute_propagate_valid(self, cn):
inputs_valid = not cn.selected_method.has_invalid_vars()
if inputs_valid:
cn.selected_method.execute()
for var in cn.selected_method.outputs:
var.valid = inputs_valid
def exec_from_cycle(self, cn):
if self._cycle is None: self._cycle = set()
self._cycle.add(cn)
# logger.DEBUG("%s -> %s" %(cn, self.immediate_marked_upstream(cn)))
# logger.DEBUG(", ".join([str([var.determined_by, var.determined_by.mark]) for var in self.variables if var.determined_by]))
if cn.mark == self.mark:
cn.mark = None
for var in cn.selected_method.outputs:
var.valid = False
for consuming_cn in var.constraints:
if consuming_cn != cn and consuming_cn.is_enforced:
self.exec_from_cycle(consuming_cn)
def pplan_add(self, objs):
pplan = []
if not isinstance(objs, set):
raise Exception("accepting only set of objs! Got %s of type %s" %(objs, type(objs)))
for el in objs:
el.add_to_pplan(pplan, self.mark)
return pplan
def _new_mark(self):
self.marker.new_mark()
self.mark = self.marker.mark
class ConstraintSystem(object):
"""This class encapsulates a set of constraints.
Usage:
>>> cs = ConstraintSystem()
>>> v1 = Variable("v1", 1, cs)
>>> v2 = Variable("v2", 2, cs)
>>> m1 = Method([v1], [v2], lambda v1: v1)
>>> m2 = Method([v2], [v2], lambda v2: v2)
>>> constraint = Constraint(
>>> lambda v1, v2: v1 == v2,
>>> Strength.STRONG,
>>> [v1, v2], [m1, m2])
>>> cs.add_constraint(constraint)
>>> v1.get_value() # => 1
>>> v2.get_value() # => 1
"""
def __init__(self):
self.marker = Marker()
self.constraints = []
self.variables = []
self.forced_constraint = None
self.check_constraints = False
self.unenforced_constraints = set()
self.redetermined_variables = set()
self.exec_roots = []
self.mark = None
self.plan = None
self._cycle = None
def create_variables(self, names, initialValues):
"""
Creates several variables at once.
>>> v1, v2, v3 = constraint_system.create_variables(["v1", "v2", "v3"], [4, 5, 3])
"""
assert len(names) == len(initialValues)
variables = []
for i in range(len(names)):
variables.append(Variable(names[i], initialValues[i], self))
return variables
def change_variable_values(self, variables, values):
"""Allows to change several variables at once.
>>> constraint_system.change_variable_values(
>>> [self.v1, self.v2],
>>> [10, 20]
>>> )
"""
assert len(variables) == len(values)
if len(variables) == 1:
values = values[0]
method = Method([], variables,
lambda: values)
constraint = Constraint(
lambda x: True,
InternalStrength.FORCED,
variables,
[method],
"set")
if self.forced_constraint is not None:
self.remove_constraint(self.forced_constraint, skip = True)
self.forced_constraint = constraint
self.add_constraint(constraint)
def _variable_changed(self, variable):
self.change_variable_values([variable], [variable.get_value()])
def _check_constraints(self):
if self.check_constraints == False:
return
for constraint in self.constraints:
if not constraint.is_enforced():
continue
check = constraint.check_function(*[var.get_value() for var in constraint.variables])
if not check:
raise Exception("Constraint %s is not satisfied" % constraint)
def _add_stay_constraint(self, variable, strength):
method = Method([], [variable], lambda: variable.get_value())
stay_constraint = Constraint(
lambda x: True,
strength,
[variable],
[method], "stay")
self.add_constraint(stay_constraint)
return stay_constraint
@fail_on_cycle
def add_constraint(self, constraint):
constraint.selected_method = None
constraint.mark = None
for variable in constraint.variables:
variable.add_constraint(constraint)
self.unenforced_constraints = set([constraint])
self.exec_roots = []
self._update_method_graph()
self._extract_plan()
self._execute_plan()
self.constraints.append(constraint)
self._check_constraints()
@fail_on_cycle
def remove_constraint(self, constraint, skip = False):
for variable in constraint.variables:
variable.remove_constraint(constraint)
self.constraints.remove(constraint)
if constraint.is_enforced():
old_outputs = set(constraint.selected_method.outputs)
constraint.selected_method = None
self.exec_roots = []
for variable in old_outputs:
variable.determined_by = None
variable.walk_strength = Strength.WEAKEST
for var_constraint in variable.constraints:
if var_constraint.is_enforced():
self.exec_roots.append(var_constraint)
if skip:
return
self._propagate_walk_strength(old_outputs)
self.unenforced_constraints = set()
self._collect_unenforced(constraint.strength, True)
self._update_method_graph()
self._extract_plan()
self._execute_plan()
self._check_constraints()
def _update_method_graph(self):
while self.unenforced_constraints:
constraint = self._remove_strongest_constraint()
self.redetermined_variables.clear()
if not Mvine(self.marker).build(constraint, self.redetermined_variables):
continue
self._propagate_walk_strength(self.redetermined_variables.union([constraint]))
self._collect_unenforced(constraint.strength, False)
self.exec_roots.append(constraint)
self.exec_roots.extend([var_constraint \
for var in self.redetermined_variables \
for var_constraint in var.constraints \
if var.determined_by is None and \
var_constraint.is_enforced()])
def _remove_strongest_constraint(self):
sorted_constraints = sorted(self.unenforced_constraints, key = lambda constraint: constraint.strength, reverse = True)
strongest_constraint = sorted_constraints[0]
self.unenforced_constraints.remove(strongest_constraint)
return strongest_constraint
def _propagate_walk_strength(self, roots):
self._new_mark()
for constraint in self._pplan_add(roots):
for var in constraint.selected_method.inputs:
if var.determined_by is not None and var.determined_by.mark == self.mark:
var.walk_strength = Strength.WEAKEST
self._compute_walkabout_strengths(constraint)
constraint.mark = None
def _compute_walkabout_strengths(self, constraint):
outs = constraint.selected_method.outputs
for out_var in outs:
max_strengths = [self._max_out(method, outs) for method in constraint.methods if out_var not in method.outputs]
max_strengths.append(constraint.strength)
out_var.walk_strength = min(max_strengths)
def _max_out(self, method, current_outputs):
return max([variable.walk_strength for variable in method.outputs if variable not in current_outputs])
def _collect_unenforced(self, collection_strength, collect_equal_strength):
self._new_mark()
for variable in self.redetermined_variables:
stack = [variable]
while stack:
cur_var = stack.pop()
for constraint in cur_var.constraints:
if constraint == cur_var.determined_by or constraint.mark == self.mark:
continue
constraint.mark = self.mark
if constraint.is_enforced():
stack.extend(constraint.selected_method.outputs)
elif Strength.weaker(constraint.strength, collection_strength) or \
(collect_equal_strength and (constraint.strength == collection_strength)):
self.unenforced_constraints.add(constraint)
def _any_immediate_upstream_marked(self, constraint):
for variable in constraint.selected_method.inputs:
if variable.determined_by is not None and variable.determined_by.mark == self.mark:
return True
return False
def _execute_propagate_valid(self, constraint):
inputs_valid = not constraint.selected_method.has_invalid_vars()
if inputs_valid:
constraint.selected_method.execute()
for variable in constraint.selected_method.outputs:
variable.valid = inputs_valid
def _pplan_add(self, objs):
pplan = []
if not isinstance(objs, set) and not isinstance(objs, list):
raise Exception("accepting only set of objs! Got %s of type %s" %(objs, type(objs)))
for el in objs:
el.add_to_pplan(pplan, self.mark)
return pplan
def _new_mark(self):
self.marker.new_mark()
self.mark = self.marker.mark
def _extract_plan(self):
good_constraints = []
bad_constraints = []
self._new_mark()
for constraint in reversed(self._pplan_add(self.exec_roots)):
if constraint.mark != self.mark:
continue
elif self._any_immediate_upstream_marked(constraint):
bad_constraints.append(constraint)
else:
constraint.mark = None
good_constraints.append(constraint)
self.plan = Plan(self.exec_roots, good_constraints, bad_constraints, True)
def _execute_plan(self):
if self.plan.valid:
for constraint in self.plan.good_constraints:
self._execute_propagate_valid(constraint)
else:
raise ValueError("trying to execute invalid plan")
from unittest import TestCase
try:
from unittest.mock import MagicMock as Mock
except ImportError as e:
from mock import Mock
from skypyblue.core import ConstraintSystem, Marker
from skypyblue.models import *
new_mark = Marker().new_mark
class HelperTests(TestCase):
def test_max_out(self):
cs = ConstraintSystem()
v1 = Variable("v1", 13, cs)
v2 = Variable("v2", 12, cs)
method = Method(v1, v2, lambda v1: v1 - 1)
self.assertEqual(Strength.WEAKEST, cs._max_out(method, [v1]))
def test_new_mark_are_numbers(self):
used_marks = set()
for i in range(100):
mark = new_mark()
self.assertTrue(mark not in used_marks)
used_marks.add(mark)
