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oopt-gnpy/gnpy/topology/request.py
Jan Kundrát 9faf6430a5 reorganization: gnpy/{core => tools}/service_sheet.py 
Change-Id: I88559cc718536f222b8ea9829bcc72a425c062ca
2020-05-23 15:23:27 +02:00

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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
gnpy.topology.request
=====================
This module contains path request functionality.
This functionality allows the user to provide a JSON request
file in accordance with a Yang model for requesting path
computations and returns path results in terms of path
and feasibility
See: draft-ietf-teas-yang-path-computation-01.txt
"""
from collections import namedtuple, OrderedDict
from logging import getLogger
from networkx import (dijkstra_path, NetworkXNoPath, all_simple_paths)
from networkx.utils import pairwise
from numpy import mean
from gnpy.core.elements import Transceiver, Roadm
from gnpy.core.utils import lin2db
from gnpy.core.info import create_input_spectral_information
from gnpy.core.exceptions import ServiceError, DisjunctionError
import gnpy.core.ansi_escapes as ansi_escapes
from gnpy.tools.service_sheet import Element
from copy import deepcopy
from csv import writer
from math import ceil
LOGGER = getLogger(__name__)
RequestParams = namedtuple('RequestParams', 'request_id source destination bidir trx_type' +
' trx_mode nodes_list loose_list spacing power nb_channel f_min' +
' f_max format baud_rate OSNR bit_rate roll_off tx_osnr' +
' min_spacing cost path_bandwidth')
DisjunctionParams = namedtuple('DisjunctionParams', 'disjunction_id relaxable link' +
'_diverse node_diverse disjunctions_req')
class PathRequest:
""" the class that contains all attributes related to a request
"""
def __init__(self, *args, **params):
params = RequestParams(**params)
self.request_id = params.request_id
self.source = params.source
self.destination = params.destination
self.bidir = params.bidir
self.tsp = params.trx_type
self.tsp_mode = params.trx_mode
self.baud_rate = params.baud_rate
self.nodes_list = params.nodes_list
self.loose_list = params.loose_list
self.spacing = params.spacing
self.power = params.power
self.nb_channel = params.nb_channel
self.f_min = params.f_min
self.f_max = params.f_max
self.format = params.format
self.OSNR = params.OSNR
self.bit_rate = params.bit_rate
self.roll_off = params.roll_off
self.tx_osnr = params.tx_osnr
self.min_spacing = params.min_spacing
self.cost = params.cost
self.path_bandwidth = params.path_bandwidth
def __str__(self):
return '\n\t'.join([f'{type(self).__name__} {self.request_id}',
f'source: {self.source}',
f'destination: {self.destination}'])
def __repr__(self):
if self.baud_rate is not None:
temp = self.baud_rate * 1e-9
temp2 = self.bit_rate * 1e-9
else:
temp = self.baud_rate
temp2 = self.bit_rate
return '\n\t'.join([f'{type(self).__name__} {self.request_id}',
f'source: \t{self.source}',
f'destination:\t{self.destination}',
f'trx type:\t{self.tsp}',
f'trx mode:\t{self.tsp_mode}',
f'baud_rate:\t{temp} Gbaud',
f'bit_rate:\t{temp2} Gb/s',
f'spacing:\t{self.spacing * 1e-9} GHz',
f'power: \t{round(lin2db(self.power)+30, 2)} dBm',
f'nb channels: \t{self.nb_channel}',
f'path_bandwidth: \t{round(self.path_bandwidth * 1e-9, 2)} Gbit/s',
f'nodes-list:\t{self.nodes_list}',
f'loose-list:\t{self.loose_list}'
'\n'])
class Disjunction:
""" the class that contains all attributes related to disjunction constraints
"""
def __init__(self, *args, **params):
params = DisjunctionParams(**params)
self.disjunction_id = params.disjunction_id
self.relaxable = params.relaxable
self.link_diverse = params.link_diverse
self.node_diverse = params.node_diverse
self.disjunctions_req = params.disjunctions_req
def __str__(self):
return '\n\t'.join([f'relaxable: {self.relaxable}',
f'link-diverse: {self.link_diverse}',
f'node-diverse: {self.node_diverse}',
f'request-id-numbers: {self.disjunctions_req}'])
def __repr__(self):
return '\n\t'.join([f'{type(self).__name__} {self.disjunction_id}',
f'relaxable: {self.relaxable}',
f'link-diverse: {self.link_diverse}',
f'node-diverse: {self.node_diverse}',
f'request-id-numbers: {self.disjunctions_req}'
'\n'])
BLOCKING_NOPATH = ['NO_PATH', 'NO_PATH_WITH_CONSTRAINT',
'NO_FEASIBLE_BAUDRATE_WITH_SPACING',
'NO_COMPUTED_SNR']
BLOCKING_NOMODE = ['NO_FEASIBLE_MODE', 'MODE_NOT_FEASIBLE']
BLOCKING_NOSPECTRUM = 'NO_SPECTRUM'
class ResultElement(Element):
def __init__(self, path_request, computed_path, reversed_computed_path=None):
self.path_id = path_request.request_id
self.path_request = path_request
self.computed_path = computed_path
# starting implementing reversed properties in case of bidir demand
if reversed_computed_path is not None:
self.reversed_computed_path = reversed_computed_path
uid = property(lambda self: repr(self))
@property
def detailed_path_json(self):
""" a function that builds path object for normal and blocking cases
"""
index = 0
pro_list = []
for element in self.computed_path:
temp = {
'path-route-object': {
'index': index,
'num-unnum-hop': {
'node-id': element.uid,
'link-tp-id': element.uid,
# TODO change index in order to insert transponder attribute
}
}
}
pro_list.append(temp)
index += 1
if self.path_request.M > 0:
temp = {
'path-route-object': {
'index': index,
"label-hop": {
"N": self.path_request.N,
"M": self.path_request.M
},
}
}
pro_list.append(temp)
index += 1
elif self.path_request.M == 0 and hasattr(self.path_request, 'blocking_reason'):
# if the path is blocked due to spectrum, no label object is created, but
# the json response includes a detailed path for user infromation.
pass
else:
raise ServiceError('request {self.path_id} should have positive path bandwidth value.')
if isinstance(element, Transceiver):
temp = {
'path-route-object': {
'index': index,
'transponder': {
'transponder-type': self.path_request.tsp,
'transponder-mode': self.path_request.tsp_mode
}
}
}
pro_list.append(temp)
index += 1
return pro_list
@property
def path_properties(self):
""" a function that returns the path properties (metrics, crossed elements) into a dict
"""
def path_metric(pth, req):
""" creates the metrics dictionary
"""
return [
{
'metric-type': 'SNR-bandwidth',
'accumulative-value': round(mean(pth[-1].snr), 2)
},
{
'metric-type': 'SNR-0.1nm',
'accumulative-value': round(mean(pth[-1].snr + lin2db(req.baud_rate / 12.5e9)), 2)
},
{
'metric-type': 'OSNR-bandwidth',
'accumulative-value': round(mean(pth[-1].osnr_ase), 2)
},
{
'metric-type': 'OSNR-0.1nm',
'accumulative-value': round(mean(pth[-1].osnr_ase_01nm), 2)
},
{
'metric-type': 'reference_power',
'accumulative-value': req.power
},
{
'metric-type': 'path_bandwidth',
'accumulative-value': req.path_bandwidth
}
]
if self.path_request.bidir:
path_properties = {
'path-metric': path_metric(self.computed_path, self.path_request),
'z-a-path-metric': path_metric(self.reversed_computed_path, self.path_request),
'path-route-objects': self.detailed_path_json
}
else:
path_properties = {
'path-metric': path_metric(self.computed_path, self.path_request),
'path-route-objects': self.detailed_path_json
}
return path_properties
@property
def pathresult(self):
""" create the result dictionnary (response for a request)
"""
try:
if self.path_request.blocking_reason in BLOCKING_NOPATH:
response = {
'response-id': self.path_id,
'no-path': {
'no-path': self.path_request.blocking_reason
}
}
return response
else:
response = {
'response-id': self.path_id,
'no-path': {
'no-path': self.path_request.blocking_reason,
'path-properties': self.path_properties
}
}
return response
except AttributeError:
response = {
'response-id': self.path_id,
'path-properties': self.path_properties
}
return response
@property
def json(self):
return self.pathresult
def compute_constrained_path(network, req):
trx = [n for n in network.nodes() if isinstance(n, Transceiver)]
anytypenode = [n for n in network.nodes()]
source = next(el for el in trx if el.uid == req.source)
# This method ensures that the constraint can be satisfied without loops
# except when it is not possible: eg if constraints makes a loop
# It requires that the source, dest and nodes are correct (no error in the names)
destination = next(el for el in trx if el.uid == req.destination)
nodes_list = []
for n_elem in req.nodes_list:
# for debug excel print(n)
nodes_list.append(next(el for el in anytypenode if el.uid == n_elem))
# nodes_list contains at least the destination
if nodes_list is None:
# only arrive here if there is a bug in the program because route lists have
# been corrected and harmonized before
msg = f'Request {req.request_id} problem in the constitution of nodes_list: ' +\
'should at least include destination'
LOGGER.critical(msg)
raise ValueError(msg)
if req.nodes_list[-1] != req.destination:
# only arrive here if there is a bug in the program because route lists have
# been corrected and harmonized before
msg = f'Request {req.request_id} malformed list of nodes: last node should ' +\
'be destination trx'
LOGGER.critical(msg)
raise ValueError()
try:
total_path = dijkstra_path(network, source, destination, weight='weight')
# print('checking edges length is correct')
# print(shortest_path_length(network,source,destination))
# print(shortest_path_length(network,source,destination,weight ='weight'))
# s = total_path[0]
# for e in total_path[1:]:
# print(s.uid)
# print(network.get_edge_data(s,e))
# s = e
except NetworkXNoPath:
msg = f'{ansi_escapes.yellow}Request {req.request_id} could not find a path from' +\
f' {source.uid} to node: {destination.uid} in network topology{ansi_escapes.reset}'
LOGGER.critical(msg)
print(msg)
req.blocking_reason = 'NO_PATH'
return []
if len(nodes_list) > 1:
# len(nodes_list) is 2 or more (includes at least one include node apart from destination)
cutoff = max(int(len(total_path) * 1.2), 150)
all_simp_pths = list(all_simple_paths(network, source=source, target=destination, cutoff=cutoff))
candidate = []
for pth in all_simp_pths:
if ispart(nodes_list, pth):
# print(f'selection{[el.uid for el in p if el in roadm]}')
candidate.append(pth)
# select the shortest path (in nb of hops) -> changed to shortest path in km length
if len(candidate) > 0:
# candidate.sort(key=lambda x: len(x))
candidate.sort(key=lambda x: sum(network.get_edge_data(x[i], x[i + 1])['weight']
for i in range(len(x) - 2)))
total_path = candidate[0]
else:
# TODO: better account for individual loose and strict node
# to ease: suppose that one strict makes the whole liste strict (except for the
# last node which is the transceiver)
# if all nodes i n node_list are LOOSE constraint, skip the constraints and find
# a path w/o constraints, else there is no possible path
# no candidate can be found with the constraints
print(f'{ansi_escapes.yellow}Request {req.request_id} could not find a path crossing ' +
f'{[el.uid for el in nodes_list[:-1]]} in network topology{ansi_escapes.reset}')
if 'STRICT' not in req.loose_list[:-1]:
msg = f'{ansi_escapes.yellow}Request {req.request_id} could not find a path with user_' +\
f'include node constraints{ansi_escapes.reset}'
LOGGER.info(msg)
print(f'constraint ignored')
else:
# one STRICT makes the whole list STRICT
msg = f'{ansi_escapes.yellow}Request {req.request_id} could not find a path with user ' +\
f'include node constraints.\nNo path computed{ansi_escapes.reset}'
LOGGER.critical(msg)
print(msg)
req.blocking_reason = 'NO_PATH_WITH_CONSTRAINT'
total_path = []
# the following method was initially used but abandonned: compute per segment:
# this does not guaranty to avoid loops or correct results
# Here is the demonstration:
# 1 1
# eg a----b-----c
# |1 |0.5 |1
# e----f--h--g
# 1 0.5 0.5
# if I have to compute a to g with constraint f-c
# result will be a concatenation of: a-b-f and f-b-c and c-g
# which means a loop.
# if to avoid loops I iteratively suppress edges of the segments in the topo
# segment 1 = a-b-f
# 1
# eg a b-----c
# |1 |1
# e----f--h--g
# 1 0.5 0.5
# then
# segment 2 = f-h-g-c
# 1
# eg a b-----c
# |1
# e----f h g
# 1
# then there is no more path to g destination
return total_path
def propagate(path, req, equipment):
si = create_input_spectral_information(
req.f_min, req.f_max, req.roll_off, req.baud_rate,
req.power, req.spacing)
for el in path:
si = el(si)
path[-1].update_snr(req.tx_osnr, equipment['Roadm']['default'].add_drop_osnr)
return path
def propagate2(path, req, equipment):
si = create_input_spectral_information(
req.f_min, req.f_max, req.roll_off, req.baud_rate,
req.power, req.spacing)
infos = {}
for el in path:
before_si = si
after_si = si = el(si)
infos[el] = before_si, after_si
path[-1].update_snr(req.tx_osnr, equipment['Roadm']['default'].add_drop_osnr)
return infos
def propagate_and_optimize_mode(path, req, equipment):
# if mode is unknown : loops on the modes starting from the highest baudrate fiting in the
# step 1: create an ordered list of modes based on baudrate
baudrate_to_explore = list(set([this_mode['baud_rate']
for this_mode in equipment['Transceiver'][req.tsp].mode
if float(this_mode['min_spacing']) <= req.spacing]))
# TODO be carefull on limits cases if spacing very close to req spacing eg 50.001 50.000
baudrate_to_explore = sorted(baudrate_to_explore, reverse=True)
if baudrate_to_explore:
# at least 1 baudrate can be tested wrt spacing
for this_br in baudrate_to_explore:
modes_to_explore = [this_mode for this_mode in equipment['Transceiver'][req.tsp].mode
if this_mode['baud_rate'] == this_br and
float(this_mode['min_spacing']) <= req.spacing]
modes_to_explore = sorted(modes_to_explore,
key=lambda x: x['bit_rate'], reverse=True)
# print(modes_to_explore)
# step2: computes propagation for each baudrate: stop and select the first that passes
# TODO: the case of roll of is not included: for now use SI one
# TODO: if the loop in mode optimization does not have a feasible path, then bugs
spc_info = create_input_spectral_information(req.f_min, req.f_max,
equipment['SI']['default'].roll_off,
this_br, req.power, req.spacing)
for el in path:
spc_info = el(spc_info)
for this_mode in modes_to_explore:
if path[-1].snr is not None:
path[-1].update_snr(this_mode['tx_osnr'], equipment['Roadm']['default'].add_drop_osnr)
if round(min(path[-1].snr + lin2db(this_br / (12.5e9))), 2) > this_mode['OSNR']:
return path, this_mode
else:
last_explored_mode = this_mode
else:
req.blocking_reason = 'NO_COMPUTED_SNR'
return path, None
# only get to this point if no baudrate/mode satisfies OSNR requirement
# returns the last propagated path and mode
msg = f'\tWarning! Request {req.request_id}: no mode satisfies path SNR requirement.\n'
print(msg)
LOGGER.info(msg)
req.blocking_reason = 'NO_FEASIBLE_MODE'
return path, last_explored_mode
else:
# no baudrate satisfying spacing
msg = f'\tWarning! Request {req.request_id}: no baudrate satisfies spacing requirement.\n'
print(msg)
LOGGER.info(msg)
req.blocking_reason = 'NO_FEASIBLE_BAUDRATE_WITH_SPACING'
return [], None
def jsontopath_metric(path_metric):
""" a functions that reads resulting metric from json string
"""
output_snr = next(e['accumulative-value']
for e in path_metric if e['metric-type'] == 'SNR-0.1nm')
output_snrbandwidth = next(e['accumulative-value']
for e in path_metric if e['metric-type'] == 'SNR-bandwidth')
output_osnr = next(e['accumulative-value']
for e in path_metric if e['metric-type'] == 'OSNR-0.1nm')
# ouput osnr@bandwidth is not used
# output_osnrbandwidth = next(e['accumulative-value']
# for e in path_metric if e['metric-type'] == 'OSNR-bandwidth')
power = next(e['accumulative-value']
for e in path_metric if e['metric-type'] == 'reference_power')
path_bandwidth = next(e['accumulative-value']
for e in path_metric if e['metric-type'] == 'path_bandwidth')
return output_snr, output_snrbandwidth, output_osnr, power, path_bandwidth
def jsontoparams(my_p, tsp, mode, equipment):
""" a function that derives optical params from transponder type and mode
supports the no mode case
"""
temp = []
for elem in my_p['path-properties']['path-route-objects']:
if 'num-unnum-hop' in elem['path-route-object']:
temp.append(elem['path-route-object']['num-unnum-hop']['node-id'])
pth = ' | '.join(temp)
temp2 = []
for elem in my_p['path-properties']['path-route-objects']:
if 'label-hop' in elem['path-route-object'].keys():
temp2.append(f'{elem["path-route-object"]["label-hop"]["N"]}, ' +
f'{elem["path-route-object"]["label-hop"]["M"]}')
# OrderedDict.fromkeys returns the unique set of strings.
# TODO: if spectrum changes along the path, we should be able to give the segments
# eg for regeneration case
temp2 = list(OrderedDict.fromkeys(temp2))
sptrm = ' | '.join(temp2)
# find the tsp minOSNR, baud rate... from the eqpt library based
# on tsp (type) and mode (format).
# loading equipment already tests the existence of tsp type and mode:
if mode is not None:
[minosnr, baud_rate, bit_rate, cost] = \
next([m['OSNR'], m['baud_rate'], m['bit_rate'], m['cost']]
for m in equipment['Transceiver'][tsp].mode if m['format'] == mode)
else:
[minosnr, baud_rate, bit_rate, cost] = ['', '', '', '']
output_snr, output_snrbandwidth, output_osnr, power, path_bandwidth = \
jsontopath_metric(my_p['path-properties']['path-metric'])
return pth, minosnr, baud_rate, bit_rate, cost, output_snr, \
output_snrbandwidth, output_osnr, power, path_bandwidth, sptrm
def jsontocsv(json_data, equipment, fileout):
""" reads json path result file in accordance with:
Yang model for requesting Path Computation
draft-ietf-teas-yang-path-computation-01.txt.
and write results in an CSV file
"""
mywriter = writer(fileout)
mywriter.writerow(('response-id', 'source', 'destination', 'path_bandwidth', 'Pass?',
'nb of tsp pairs', 'total cost', 'transponder-type', 'transponder-mode',
'OSNR-0.1nm', 'SNR-0.1nm', 'SNR-bandwidth', 'baud rate (Gbaud)',
'input power (dBm)', 'path', 'spectrum (N,M)', 'reversed path OSNR-0.1nm',
'reversed path SNR-0.1nm', 'reversed path SNR-bandwidth'))
for pth_el in json_data['response']:
path_id = pth_el['response-id']
if 'no-path' in pth_el.keys():
total_cost = ''
nb_tsp = ''
sptrm = ''
if pth_el['no-path']['no-path'] in BLOCKING_NOPATH:
source = ''
destination = ''
pthbdbw = ''
isok = pth_el['no-path']['no-path']
tsp = ''
mode = ''
rosnr = ''
rsnr = ''
rsnrb = ''
brate = ''
pwr = ''
pth = ''
revosnr = ''
revsnr = ''
revsnrb = ''
else:
# the objects are listed with this order:
# - id of hop
# - label (N,M)
# - transponder for source and destination only
# as spectrum assignment is not performed for blocked demands: there is no label object in the answer
# so the hop_attribute with tsp and mode is second object or last object, while id of hop is first and
# penultimate
source = pth_el['no-path']['path-properties']['path-route-objects'][0]['path-route-object']['num-unnum-hop']['node-id']
destination = pth_el['no-path']['path-properties']['path-route-objects'][-2]['path-route-object']['num-unnum-hop']['node-id']
temp_tsp = pth_el['no-path']['path-properties']['path-route-objects'][1]['path-route-object']['transponder']
tsp = temp_tsp['transponder-type']
mode = temp_tsp['transponder-mode']
isok = pth_el['no-path']['no-path']
if pth_el['no-path']['no-path'] in BLOCKING_NOMODE or \
pth_el['no-path']['no-path'] in BLOCKING_NOSPECTRUM:
pth, minosnr, baud_rate, bit_rate, cost, output_snr, output_snrbandwidth, \
output_osnr, power, path_bandwidth, sptrm = \
jsontoparams(pth_el['no-path'], tsp, mode, equipment)
pthbdbw = ''
rosnr = round(output_osnr, 2)
rsnr = round(output_snr, 2)
rsnrb = round(output_snrbandwidth, 2)
brate = round(baud_rate * 1e-9, 2)
pwr = round(lin2db(power) + 30, 2)
if 'z-a-path-metric' in pth_el['no-path']['path-properties'].keys():
output_snr, output_snrbandwidth, output_osnr, power, path_bandwidth = \
jsontopath_metric(pth_el['no-path']['path-properties']['z-a-path-metric'])
revosnr = round(output_osnr, 2)
revsnr = round(output_snr, 2)
revsnrb = round(output_snrbandwidth, 2)
else:
revosnr = ''
revsnr = ''
revsnrb = ''
else:
# when label will be assigned destination will be with index -3, and transponder with index 2
source = pth_el['path-properties']['path-route-objects'][0]['path-route-object']['num-unnum-hop']['node-id']
destination = pth_el['path-properties']['path-route-objects'][-3]['path-route-object']['num-unnum-hop']['node-id']
# selects only roadm nodes
temp_tsp = pth_el['path-properties']['path-route-objects'][2]['path-route-object']['transponder']
tsp = temp_tsp['transponder-type']
mode = temp_tsp['transponder-mode']
# find the min acceptable OSNR, baud rate from the eqpt library based
# on tsp (type) and mode (format).
# loading equipment already tests the existence of tsp type and mode:
pth, minosnr, baud_rate, bit_rate, cost, output_snr, output_snrbandwidth, \
output_osnr, power, path_bandwidth, sptrm = \
jsontoparams(pth_el, tsp, mode, equipment)
# this part only works if the request has a blocking_reason atribute, ie if it could not be satisfied
isok = output_snr >= minosnr
nb_tsp = ceil(path_bandwidth / bit_rate)
pthbdbw = round(path_bandwidth * 1e-9, 2)
rosnr = round(output_osnr, 2)
rsnr = round(output_snr, 2)
rsnrb = round(output_snrbandwidth, 2)
brate = round(baud_rate * 1e-9, 2)
pwr = round(lin2db(power) + 30, 2)
total_cost = nb_tsp * cost
if 'z-a-path-metric' in pth_el['path-properties'].keys():
output_snr, output_snrbandwidth, output_osnr, power, path_bandwidth = \
jsontopath_metric(pth_el['path-properties']['z-a-path-metric'])
revosnr = round(output_osnr, 2)
revsnr = round(output_snr, 2)
revsnrb = round(output_snrbandwidth, 2)
else:
revosnr = ''
revsnr = ''
revsnrb = ''
mywriter.writerow((path_id,
source,
destination,
pthbdbw,
isok,
nb_tsp,
total_cost,
tsp,
mode,
rosnr,
rsnr,
rsnrb,
brate,
pwr,
pth,
sptrm,
revosnr,
revsnr,
revsnrb
))
def compute_path_dsjctn(network, equipment, pathreqlist, disjunctions_list):
# pathreqlist is a list of PathRequest objects
# disjunctions_list a list of Disjunction objects
# given a network, a list of requests with the set of disjunction features between
# request, the function computes the set of path satisfying: first the disjunction
# constraint and second the routing constraint if the request include an explicit
# set of elements to pass through.
# the algorithm used allows to specify disjunction for demands not sharing source or
# destination.
# a request might be declared as disjoint from several requests
# it is a iterative process:
# first computes a list of all shortest path (this may add computation time)
# second elaborate the set of path solution for each synchronization vector
# third select only the candidates that satisfy all synchronization vectors they belong to
# fourth apply route constraints: remove candidate path that do not satisfy the constraint
# fifth select the first candidate among the set of candidates.
# the example network used in comments has been added to the set of data tests files
# define the list to be returned
path_res_list = []
# all disjctn must be computed at once together to avoid blocking
# 1 1
# eg a----b-----c
# |1 |0.5 |1
# e----f--h--g
# 1 0.5 0.5
# if I have to compute a to g and a to h
# I must not compute a-b-f-h-g, otherwise there is no disjoint path remaining for a to h
# instead I should list all most disjoint path and select the one that have the less
# number of commonalities
# \ path abfh aefh abcgh
# \___cost 2 2.5 3.5
# path| cost
# abfhg| 2.5 x x
# abcg | 3 x x
# aefhg| 3 x x x
# from this table abcg and aefh have no common links and should be preferred
# even they are not the shortest paths
# build the list of pathreqlist elements not concerned by disjunction
global_disjunctions_list = [e for d in disjunctions_list for e in d.disjunctions_req]
pathreqlist_simple = [e for e in pathreqlist if e.request_id not in global_disjunctions_list]
pathreqlist_disjt = [e for e in pathreqlist if e.request_id in global_disjunctions_list]
# use a mirror class to record path and the corresponding requests
class Pth:
def __init__(self, req, pth, simplepth):
self.req = req
self.pth = pth
self.simplepth = simplepth
# step 1
# for each remaining request compute a set of simple path
allpaths = {}
rqs = {}
simple_rqs = {}
simple_rqs_reversed = {}
for pathreq in pathreqlist_disjt:
all_simp_pths = list(all_simple_paths(network,
source=next(el for el in network.nodes() if el.uid == pathreq.source),
target=next(el for el in network.nodes()
if el.uid == pathreq.destination),
cutoff=80))
# sort them in km length instead of hop
# all_simp_pths = sorted(all_simp_pths, key=lambda path: len(path))
all_simp_pths = sorted(all_simp_pths, key=lambda
x: sum(network.get_edge_data(x[i], x[i + 1])['weight'] for i in range(len(x) - 2)))
# reversed direction paths required to check disjunction on both direction
all_simp_pths_reversed = []
for pth in all_simp_pths:
all_simp_pths_reversed.append(find_reversed_path(pth))
rqs[pathreq.request_id] = all_simp_pths
temp = []
for pth in all_simp_pths:
# build a short list representing each roadm+direction with the first item
# start enumeration at 1 to avoid Trx in the list
short_list = [e.uid for i, e in enumerate(pth[1:-1])
if isinstance(e, Roadm) | (isinstance(pth[i], Roadm))]
temp.append(short_list)
# id(short_list) is unique even if path is the same: two objects with same
# path have two different ids
allpaths[id(short_list)] = Pth(pathreq, pth, short_list)
simple_rqs[pathreq.request_id] = temp
temp = []
for pth in all_simp_pths_reversed:
# build a short list representing each roadm+direction with the first item
# start enumeration at 1 to avoid Trx in the list
temp.append([e.uid for i, e in enumerate(pth[1:-1])
if isinstance(e, Roadm) | (isinstance(pth[i], Roadm))])
simple_rqs_reversed[pathreq.request_id] = temp
# step 2
# for each set of requests that need to be disjoint
# select the disjoint path combination
candidates = {}
for dis in disjunctions_list:
dlist = dis.disjunctions_req.copy()
# each line of dpath is one combination of path that satisfies disjunction
dpath = []
for i, pth in enumerate(simple_rqs[dlist[0]]):
dpath.append([pth])
# in each loop, dpath is updated with a path for rq that satisfies
# disjunction with each path in dpath
# for example, assume set of requests in the vector (disjunction_list) is {rq1,rq2, rq3}
# rq1 p1: abfhg
# p2: aefhg
# p3: abcg
# rq2 p8: bf
# rq3 p4: abcgh
# p6: aefh
# p7: abfh
# initiate with rq1
# dpath = [[p1]
# [p2]
# [p3]]
# after first loop:
# dpath = [[p1 p8]
# [p3 p8]]
# since p2 and p8 are not disjoint
# after second loop:
# dpath = [ p3 p8 p6 ]
# since p1 and p4 are not disjoint
# p1 and p7 are not disjoint
# p3 and p4 are not disjoint
# p3 and p7 are not disjoint
for elem1 in dlist[1:]:
temp = []
for j, pth1 in enumerate(simple_rqs[elem1]):
# can use index j in simple_rqs_reversed because index
# of direct and reversed paths have been kept identical
pth1_reversed = simple_rqs_reversed[elem1][j]
# print(pth1_reversed)
# print('\n\n')
for cndt in dpath:
# print(f' c: \t{c}')
temp2 = cndt.copy()
all_disjoint = 0
for pth in cndt:
all_disjoint += isdisjoint(pth1, pth) + isdisjoint(pth1_reversed, pth)
if all_disjoint == 0:
temp2.append(pth1)
temp.append(temp2)
# print(f' coucou {elem1}: \t{temp}')
dpath = temp
# print(dpath)
candidates[dis.disjunction_id] = dpath
# for i in disjunctions_list:
# print(f'\n{candidates[i.disjunction_id]}')
# step 3
# now for each request, select the path that satisfies all disjunctions
# path must be in candidates[id] for all concerned ids
# for example, assume set of sync vectors (disjunction groups) is
# s1 = {rq1 rq2} s2 = {rq1 rq3}
# candidate[s1] = [[p1 p8]
# [p3 p8]]
# candidate[s2] = [[p3 p6]]
# for rq1 p3 should be preferred
for pathreq in pathreqlist_disjt:
concerned_d_id = [d.disjunction_id for d in disjunctions_list
if pathreq.request_id in d.disjunctions_req]
# for each set of solution, verify that the same path is used for the same request
candidate_paths = simple_rqs[pathreq.request_id]
# print('coucou')
# print(pathreq.request_id)
for pth in candidate_paths:
iscandidate = 0
for sol in concerned_d_id:
test = 1
# for each solution test if pth is part of the solution
# if yes, then pth can remain a candidate
for cndt in candidates[sol]:
if pth in cndt:
if allpaths[id(cndt[cndt.index(pth)])].req.request_id == pathreq.request_id:
test = 0
break
iscandidate += test
if iscandidate != 0:
for this_id in concerned_d_id:
for cndt in candidates[this_id]:
if pth in cndt:
candidates[this_id].remove(cndt)
# for i in disjunctions_list:
# print(i.disjunction_id)
# print(f'\n{candidates[i.disjunction_id]}')
# step 4 apply route constraints: remove candidate path that do not satisfy
# the constraint only in the case of disjounction: the simple path is processed in
# request.compute_constrained_path
# TODO: keep a version without the loose constraint
for this_d in disjunctions_list:
temp = []
for j, sol in enumerate(candidates[this_d.disjunction_id]):
testispartok = True
for pth in sol:
# print(f'test {allpaths[id(pth)].req.request_id}')
# print(f'length of route {len(allpaths[id(pth)].req.nodes_list)}')
if allpaths[id(pth)].req.nodes_list:
# if pth does not containt the ordered list node, remove sol from the candidate
# except if this was the last solution: then check if the constraint is loose
# or not
if not ispart(allpaths[id(pth)].req.nodes_list, pth):
# print(f'nb of solutions {len(temp)}')
if j < len(candidates[this_d.disjunction_id]) - 1:
msg = f'removing {sol}'
LOGGER.info(msg)
testispartok = False
# break
else:
if 'LOOSE' in allpaths[id(pth)].req.loose_list:
LOGGER.info(f'Could not apply route constraint' +
f'{allpaths[id(pth)].req.nodes_list} on request' +
f' {allpaths[id(pth)].req.request_id}')
else:
LOGGER.info(f'removing last solution from candidate paths\n{sol}')
testispartok = False
if testispartok:
temp.append(sol)
candidates[this_d.disjunction_id] = temp
# step 5 select the first combination that works
pathreslist_disjoint = {}
for dis in disjunctions_list:
test_sol = True
while test_sol:
# print('coucou')
if candidates[dis.disjunction_id]:
for pth in candidates[dis.disjunction_id][0]:
if allpaths[id(pth)].req in pathreqlist_disjt:
# print(f'selected path:{pth} for req {allpaths[id(pth)].req.request_id}')
pathreslist_disjoint[allpaths[id(pth)].req] = allpaths[id(pth)].pth
pathreqlist_disjt.remove(allpaths[id(pth)].req)
candidates = remove_candidate(candidates, allpaths, allpaths[id(pth)].req, pth)
test_sol = False
else:
msg = f'No disjoint path found with added constraint'
LOGGER.critical(msg)
print(f'{msg}\nComputation stopped.')
# TODO in this case: replay step 5 with the candidate without constraints
raise DisjunctionError(msg)
# for i in disjunctions_list:
# print(i.disjunction_id)
# print(f'\n{candidates[i.disjunction_id]}')
# list the results in the same order as initial pathreqlist
for req in pathreqlist:
req.nodes_list.append(req.destination)
# we assume that the destination is a strict constraint
req.loose_list.append('STRICT')
if req in pathreqlist_simple:
path_res_list.append(compute_constrained_path(network, req))
else:
path_res_list.append(pathreslist_disjoint[req])
return path_res_list
def isdisjoint(pth1, pth2):
""" returns 0 if disjoint
"""
edge1 = list(pairwise(pth1))
edge2 = list(pairwise(pth2))
for edge in edge1:
if edge in edge2:
return 1
return 0
def find_reversed_path(pth):
""" select of intermediate roadms and find the path between them
note that this function may not give an exact result in case of multiple
links between two adjacent nodes.
"""
# TODO add some indication on elements to indicate from which other they
# are the reversed direction. This is partly done with oms indication
# we want the list of crossed oms and each item must be unique in the list:
# since a succession of elements of the path can be in the same oms, a 'unique'
# function is needed
# the OrderedDict.fromkeys function does this. eg
# pth = [el1_oms1 el2_oms1 el3_oms1 el1_oms2 el2_oms2 el3_oms2]
# p_oms should be = [oms1 oms2]
p_oms = list(OrderedDict.fromkeys(reversed([el.oms.reversed_oms for el in pth
if not isinstance(el, Transceiver) and not isinstance(el, Roadm)])))
reversed_path = [pth[-1]]
for oms in p_oms:
if oms is not None:
reversed_path.extend(oms.el_list)
# similarly each oms starts and ends with a roadm so roadm may be repeated
# if we don't use the OrderedDict.fromkeys function. eg:
# if oms1 = [roadma el1 el2 roadmb] and oms2 = [roadmb el3 el4 roadmc]
# concatenation should be [roadma el1 el2 roadmb el3 el4 roadmc]
reversed_path = list(OrderedDict.fromkeys(reversed_path))
else:
msg = f'Error while handling reversed path {pth[-1].uid} to {pth[0].uid}:' +\
' can not handle unidir topology. TO DO.'
LOGGER.critical(msg)
raise ValueError(msg)
reversed_path.append(pth[0])
return reversed_path
def ispart(ptha, pthb):
""" the functions takes two paths a and b and retrns True
if all a elements are part of b and in the same order
"""
j = 0
for elem in ptha:
if elem in pthb:
if pthb.index(elem) >= j:
j = pthb.index(elem)
else:
return False
else:
return False
return True
def remove_candidate(candidates, allpaths, rqst, pth):
""" filter duplicate candidates
"""
# print(f'coucou {rqst.request_id}')
for key, candidate in candidates.items():
temp = candidate.copy()
for sol in candidate:
for this_p in sol:
if allpaths[id(this_p)].req.request_id == rqst.request_id:
if id(this_p) != id(pth):
temp.remove(sol)
break
candidates[key] = temp
return candidates
def compare_reqs(req1, req2, disjlist):
""" compare two requests: returns True or False
"""
dis1 = [d for d in disjlist if req1.request_id in d.disjunctions_req]
dis2 = [d for d in disjlist if req2.request_id in d.disjunctions_req]
same_disj = False
if dis1 and dis2:
temp1 = []
for this_d in dis1:
temp1.extend(this_d.disjunctions_req)
temp1.remove(req1.request_id)
temp2 = []
for this_d in dis2:
temp2.extend(this_d.disjunctions_req)
temp2.remove(req2.request_id)
if set(temp1) == set(temp2):
same_disj = True
elif not dis2 and not dis1:
same_disj = True
if req1.source == req2.source and \
req1.destination == req2.destination and \
req1.tsp == req2.tsp and \
req1.tsp_mode == req2.tsp_mode and \
req1.baud_rate == req2.baud_rate and \
req1.nodes_list == req2.nodes_list and \
req1.loose_list == req2.loose_list and \
req1.spacing == req2.spacing and \
req1.power == req2.power and \
req1.nb_channel == req2.nb_channel and \
req1.f_min == req2.f_min and \
req1.f_max == req2.f_max and \
req1.format == req2.format and \
req1.OSNR == req2.OSNR and \
req1.roll_off == req2.roll_off and \
same_disj:
return True
else:
return False
def requests_aggregation(pathreqlist, disjlist):
""" this function aggregates requests so that if several requests
exist between same source and destination and with same transponder type
"""
# todo maybe add conditions on mode ??, spacing ...
# currently if undefined takes the default values
local_list = pathreqlist.copy()
for req in pathreqlist:
for this_r in local_list:
if req.request_id != this_r.request_id and compare_reqs(req, this_r, disjlist):
# aggregate
this_r.path_bandwidth += req.path_bandwidth
temp_r_id = this_r.request_id
this_r.request_id = ' | '.join((this_r.request_id, req.request_id))
# remove request from list
local_list.remove(req)
# todo change also disjunction req with new demand
for this_d in disjlist:
if req.request_id in this_d.disjunctions_req:
this_d.disjunctions_req.remove(req.request_id)
this_d.disjunctions_req.append(this_r.request_id)
for this_d in disjlist:
if temp_r_id in this_d.disjunctions_req:
disjlist.remove(this_d)
break
return local_list, disjlist
def correct_json_route_list(network, pathreqlist):
""" all names in list should be exact name in the network, and there is no ambiguity
This function only checks that list is correct, warns user if the name is incorrect and
suppresses the constraint it it is loose or raises an error if it is strict
"""
all_uid = [n.uid for n in network.nodes()]
transponders = [n.uid for n in network.nodes() if isinstance(n, Transceiver)]
for pathreq in pathreqlist:
if pathreq.source not in transponders:
msg = f'{ansi_escapes.red}Request: {pathreq.request_id}: could not find transponder' +\
f' source : {pathreq.source}.{ansi_escapes.reset}'
LOGGER.critical(msg)
raise ServiceError(msg)
if pathreq.destination not in transponders:
msg = f'{ansi_escapes.red}Request: {pathreq.request_id}: could not find transponder' +\
f' destination : {pathreq.destination}.{ansi_escapes.reset}'
LOGGER.critical(msg)
raise ServiceError(msg)
# silently remove source and dest nodes from the list
if pathreq.nodes_list and pathreq.source == pathreq.nodes_list[0]:
pathreq.loose_list.pop(0)
pathreq.nodes_list.pop(0)
if pathreq.nodes_list and pathreq.destination == pathreq.nodes_list[-1]:
pathreq.loose_list.pop(-1)
pathreq.nodes_list.pop(-1)
temp = deepcopy(pathreq)
for i, n_id in enumerate(temp.nodes_list):
# a node within this list must be part of the topology and should not be a transceiver,
# because only source and dest are transceivers
if n_id not in all_uid or n_id in transponders:
if temp.loose_list[i] == 'LOOSE':
# if no matching can be found in the network just ignore this constraint
# if it is a loose constraint
# warns the user that this node is not part of the topology
msg = f'{ansi_escapes.yellow}invalid route node specified:\n\t\'{n_id}\',' +\
f' could not use it as constraint, skipped!{ansi_escapes.reset}'
print(msg)
LOGGER.info(msg)
pathreq.loose_list.pop(pathreq.nodes_list.index(n_id))
pathreq.nodes_list.remove(n_id)
else:
msg = f'{ansi_escapes.red}could not find node:\n\t \'{n_id}\' in network' +\
f' topology. Strict constraint can not be applied.{ansi_escapes.reset}'
LOGGER.critical(msg)
raise ServiceError(msg)
return pathreqlist
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