class ARule(Composer):
"""
Applies the transformation on one match.
"""
def __init__(self, LHS, RHS):
"""
Applies the transformation on one match.
@param LHS: The pre-condition pattern (LHS + NACs).
@param RHS: The post-condition pattern (RHS).
"""
super(ARule, self).__init__()
self.M = Matcher(condition=LHS, max=1)
self.I = Iterator(max_iterations=1)
self.W = Rewriter(condition=RHS)
def packet_in(self, packet):
self.exception = None
self.is_success = False
# Match
packet = self.M.packet_in(packet)
if not self.M.is_success:
self.exception = self.M.exception
return packet
# Choose the only match
packet = self.I.packet_in(packet)
if not self.I.is_success:
self.exception = self.I.exception
return packet
# Rewrite
packet = self.W.packet_in(packet)
if not self.W.is_success:
self.exception = self.W.exception
return packet
# Output success packet
self.is_success = True
return packet
class LFRule(LRule):
"""
Applies an inner rule for each application of the outer rule.
"""
def __init__(self, LHS, RHS, inner_rule, outer_first, max_iterations=INFINITY):
"""
Applies an inner rule for each application of the outer rule.
@param LHS: The pre-condition pattern (LHS + NACs).
@param RHS: The post-condition pattern (RHS).
@param inner_rule: The rule to apply in the loop.
@param outer_first: Whether the outer rule should be applied before the inner rule.
@param max_iterations: The maximum number of matches of the LHS.
"""
super(LFRule, self).__init__(LHS, inner_rule, max_iterations)
self.W = Rewriter(condition=RHS)
self.outer_first = outer_first
self.inner_rule = inner_rule
def packet_in(self, packet):
self.exception = None
self.is_success = False
# Match
packet = self.M.packet_in(packet)
if not self.M.is_success:
self.exception = self.M.exception
return packet
# Choose the first match
packet = self.I.packet_in(packet)
if not self.I.is_success:
self.exception = self.I.exception
return packet
while True:
if self.outer_first:
# Rewrite
packet = self.W.packet_in(packet)
if not self.W.is_success:
self.exception = self.W.exception
return packet
if not self.ignore_resolver:
# Resolve any conflicts if necessary
packet = self.R.packet_in(packet)
if not self.R.is_success:
self.exception = self.R.exception
return packet
# Apply the inner rule
packet = self.inner_rule.packet_in(packet)
if not self.inner_rule.is_success:
self.exception = self.inner_rule.exception
return packet
if not self.outer_first:
# Rewrite
packet = self.W.packet_in(packet)
if not self.W.is_success:
self.exception = self.W.exception
return packet
if not self.ignore_resolver:
# Resolve any conflicts if necessary
packet = self.R.packet_in(packet)
if not self.R.is_success:
self.exception = self.R.exception
return packet
# Choose another match
packet = self.I.next_in(packet)
# No more iterations are left
if not self.I.is_success:
if self.I.exception:
self.exception = self.I.exception
else:
# Output success packet
self.is_success = True
return packet
class LSRule(LRule):
'''
Applies an inner rule for each application of the outer rule as long as matches can be found.
'''
def __init__(self, LHS, RHS, inner_rule, outer_first, max_iterations=INFINITY):
'''
Applies an inner rule for each application of the outer rule as long as matches can be found.
@param LHS: The pre-condition pattern (LHS + NACs).
@param RHS: The post-condition pattern (RHS).
@param inner_rule: The rule to apply in the loop.
@param outer_first: Whether the outer rule should be applied before the inner rule.
@param max_iterations: The maximum number of matches of the LHS.
'''
super(LSRule, self).__init__(LHS, inner_rule, max_iterations)
self.W = Rewriter(condition=RHS)
self.outer_first = outer_first
def packet_in(self, packet):
self.exception = None
self.is_success = False
# Match
packet = self.M.packet_in(packet)
if not self.M.is_success:
self.exception = self.M.exception
return packet
# Choose the first match
packet = self.I.packet_in(packet)
if not self.I.is_success:
self.exception = self.I.exception
return packet
while True:
if self.outer_first:
# Rewrite
packet = self.W.packet_in(packet)
if not self.W.is_success:
self.exception = self.W.exception
return packet
# Apply the inner rule
packet = self.inner_rule.packet_in(packet)
if not self.inner_rule.is_success:
self.exception = self.inner_rule.exception
return packet
if not self.outer_first:
# Rewrite
packet = self.W.packet_in(packet)
if not self.W.is_success:
self.exception = self.W.exception
return packet
# Rule has been applied once, so it's a success anyway
self.is_success = True
if self.I.iterations == self.I.max_iterations:
return packet
# Re-Match
packet = self.M.packet_in(packet)
if not self.M.is_success:
self.exception = self.M.exception
return packet
# Choose another match
packet = self.I.next_in(packet)
# No more iterations are left
if not self.I.is_success:
if self.I.exception:
self.exception = self.I.exception
return packet