Source code for sts.headerspace.headerspace.slice

'''
Created on Jan 26, 2011

@author: peymankazemian
'''

from sts.headerspace.headerspace.tf import TF

class Slice(object):
  '''
  classdocs
  '''
  def __init__(self, length):
    '''
    Constructor
    '''
    self.length = length
    self.reservations = []
    self.port_to_reservation = {}

  def get_port_reservation(self,port):
    if "%s"%port in self.port_to_reservation:
      return self.port_to_reservation["%s"%port]
    else:
      return []

  def set_hs_reservation(self, ports, hs):
    '''
    set hs reservation on @port to new_hs
    NOTE: hs.hs_list MUST have only one wildcard expression
    '''
    if hs.length != self.length:
      return None
    hs_copy = hs.copy()
    port_list = list(ports)
    self.reservations.append((port_list,hs_copy))
    for port in ports:
      if "%s"%port not in self.port_to_reservation.keys():
        self.port_to_reservation["%s"%port] = []
      self.port_to_reservation["%s"%port].append(hs)

  def intersect(self,other_slice):
    result = Slice(self.length)
    for (port_list1,hs1) in other_slice.reservations:
      for (port_list2,hs2) in self.reservations:
        port_isect = [p for p in port_list1 if p in port_list2]
        if len(port_isect) > 0:
          ihs = hs1.copy_intersect(hs2)
          if ihs.count() > 0:
            result.set_hs_reservation(port_isect, ihs)

    return result

  def __str__(self):
    result = ""
    for (p, hs) in self.reservations:
      result = result + "Port: %s - Header Space:\n %s\n"%(p,hs)
    return result