#---------------------------------------------------------------------- # Copyright (c) 2008 Board of Trustees, Princeton University # # Permission is hereby granted, free of charge, to any person obtaining # a copy of this software and/or hardware specification (the "Work") to # deal in the Work without restriction, including without limitation the # rights to use, copy, modify, merge, publish, distribute, sublicense, # and/or sell copies of the Work, and to permit persons to whom the Work # is furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be # included in all copies or substantial portions of the Work. # # THE WORK IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT # HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE WORK OR THE USE OR OTHER DEALINGS # IN THE WORK. #---------------------------------------------------------------------- import re import sys from sfa.util.faults import SfaAPIError # for convenience and smoother translation - we should get rid of these functions eventually def get_leaf(hrn): return Xrn(hrn).get_leaf() def get_authority(hrn): return Xrn(hrn).get_authority_hrn() def urn_to_hrn(urn): xrn=Xrn(urn); return (xrn.hrn, xrn.type) def hrn_to_urn(hrn,type): return Xrn(hrn, type=type).urn def hrn_authfor_hrn(parenthrn, hrn): return Xrn.hrn_is_auth_for_hrn(parenthrn, hrn) def urn_to_sliver_id(urn, slice_id, node_id, index=0): return Xrn(urn).get_sliver_id(slice_id, node_id, index) class Xrn: ########## basic tools on HRNs # split a HRN-like string into pieces # this is like split('.') except for escaped (backslashed) dots # e.g. hrn_split ('a\.b.c.d') -> [ 'a\.b','c','d'] @staticmethod def hrn_split(hrn): return [ x.replace('--sep--','\\.') for x in hrn.replace('\\.','--sep--').split('.') ] # e.g. hrn_leaf ('a\.b.c.d') -> 'd' @staticmethod def hrn_leaf(hrn): return Xrn.hrn_split(hrn)[-1] # e.g. hrn_auth_list ('a\.b.c.d') -> ['a\.b', 'c'] @staticmethod def hrn_auth_list(hrn): return Xrn.hrn_split(hrn)[0:-1] # e.g. hrn_auth ('a\.b.c.d') -> 'a\.b.c' @staticmethod def hrn_auth(hrn): return '.'.join(Xrn.hrn_auth_list(hrn)) # e.g. escape ('a.b') -> 'a\.b' @staticmethod def escape(token): return re.sub(r'([^\\])\.', r'\1\.', token) # e.g. unescape ('a\.b') -> 'a.b' @staticmethod def unescape(token): return token.replace('\\.','.') # Return the HRN authority chain from top to bottom. # e.g. hrn_auth_chain('a\.b.c.d') -> ['a\.b', 'a\.b.c'] @staticmethod def hrn_auth_chain(hrn): parts = Xrn.hrn_auth_list(hrn) chain = [] for i in range(len(parts)): chain.append('.'.join(parts[:i+1])) # Include the HRN itself? #chain.append(hrn) return chain # Is the given HRN a true authority over the namespace of the other # child HRN? # A better alternative than childHRN.startswith(parentHRN) # e.g. hrn_is_auth_for_hrn('a\.b', 'a\.b.c.d') -> True, # but hrn_is_auth_for_hrn('a', 'a\.b.c.d') -> False # Also hrn_is_uauth_for_hrn('a\.b.c.d', 'a\.b.c.d') -> True @staticmethod def hrn_is_auth_for_hrn(parenthrn, hrn): if parenthrn == hrn: return True for auth in Xrn.hrn_auth_chain(hrn): if parenthrn == auth: return True return False URN_PREFIX = "urn:publicid:IDN" ########## basic tools on URNs @staticmethod def urn_full (urn): if urn.startswith(Xrn.URN_PREFIX): return urn else: return Xrn.URN_PREFIX+urn @staticmethod def urn_meaningful (urn): if urn.startswith(Xrn.URN_PREFIX): return urn[len(Xrn.URN_PREFIX):] else: return urn @staticmethod def urn_split (urn): return Xrn.urn_meaningful(urn).split('+') #################### # the local fields that are kept consistent # self.urn # self.hrn # self.type # self.path # provide either urn, or (hrn + type) def __init__ (self, xrn, type=None): if not xrn: xrn = "" # user has specified xrn : guess if urn or hrn if xrn.startswith(Xrn.URN_PREFIX): self.hrn=None self.urn=xrn self.urn_to_hrn() #print>>sys.stderr, " \r\n \r\n \t XRN.PY init xrn.startswith(Xrn.URN_PREFIX) hrn %s urn %s type %s" %( self.hrn, self.urn, self.type) else: self.urn=None self.hrn=xrn self.type=type self.hrn_to_urn() #print>>sys.stderr, " \r\n \r\n \t XRN.PY init ELSE hrn %s urn %s type %s" %( self.hrn, self.urn, self.type) # happens all the time .. # if not type: # debug_logger.debug("type-less Xrn's are not safe") def __repr__ (self): result=">sys.stderr, " \r\n \r\n \t XRN.PY _normalize self.hrn %s ",self.hrn if self.hrn is None: raise SfaAPIError, "Xrn._normalize" if not hasattr(self,'leaf'): self.leaf=Xrn.hrn_split(self.hrn)[-1] # self.authority keeps a list if not hasattr(self,'authority'): self.authority=Xrn.hrn_auth_list(self.hrn) #print>>sys.stderr, " \r\n \r\n \t XRN.PY _normalize self.hrn %s leaf %s authority %s"%(self.hrn, self.leaf, self.authority) def get_leaf(self): self._normalize() return self.leaf def get_authority_hrn(self): self._normalize() return '.'.join( self.authority ) def get_authority_urn(self): self._normalize() return ':'.join( [Xrn.unescape(x) for x in self.authority] ) def get_sliver_id(self, slice_id, node_id, index=0): self._normalize() return ":".join(map(str, [self.get_urn(), slice_id, node_id, index])) def urn_to_hrn(self): """ compute tuple (hrn, type) from urn """ # if not self.urn or not self.urn.startswith(Xrn.URN_PREFIX): if not self.urn.startswith(Xrn.URN_PREFIX): raise SfaAPIError, "Xrn.urn_to_hrn" parts = Xrn.urn_split(self.urn) type=parts.pop(2) # Remove the authority name (e.g. '.sa') if type == 'authority': name = parts.pop() # Drop the sa. This is a bad hack, but its either this # or completely change how record types are generated/stored if name != 'sa': type = type + "+" + name name ="" else: name = parts.pop(len(parts)-1) # convert parts (list) into hrn (str) by doing the following # 1. remove blank parts # 2. escape dots inside parts # 3. replace ':' with '.' inside parts # 3. join parts using '.' hrn = '.'.join([Xrn.escape(part).replace(':','.') for part in parts if part]) # dont replace ':' in the name section if name: hrn += '.%s' % Xrn.escape(name) self.hrn=str(hrn) self.type=str(type) def hrn_to_urn(self): """ compute urn from (hrn, type) """ # if not self.hrn or self.hrn.startswith(Xrn.URN_PREFIX): if self.hrn.startswith(Xrn.URN_PREFIX): raise SfaAPIError, "Xrn.hrn_to_urn, hrn=%s"%self.hrn if self.type and self.type.startswith('authority'): self.authority = Xrn.hrn_split(self.hrn) type_parts = self.type.split("+") self.type = type_parts[0] name = 'sa' if len(type_parts) > 1: name = type_parts[1] else: self.authority = Xrn.hrn_auth_list(self.hrn) name = Xrn.hrn_leaf(self.hrn) authority_string = self.get_authority_urn() if self.type == None: urn = "+".join(['',authority_string,Xrn.unescape(name)]) else: urn = "+".join(['',authority_string,self.type,Xrn.unescape(name)]) self.urn = Xrn.URN_PREFIX + urn def dump_string(self): result="-------------------- XRN\n" result += "URN=%s\n"%self.urn result += "HRN=%s\n"%self.hrn result += "TYPE=%s\n"%self.type result += "LEAF=%s\n"%self.get_leaf() result += "AUTH(hrn format)=%s\n"%self.get_authority_hrn() result += "AUTH(urn format)=%s\n"%self.get_authority_urn() return result