60 lines
2.5 KiB
Python
60 lines
2.5 KiB
Python
import time
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from server.trackdirect.repositories.PacketRepository import PacketRepository
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from server.trackdirect.websocket.queries.MissingPacketsQuery import MissingPacketsQuery
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class MostRecentPacketsQuery:
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"""This query class returns the latest packet for moving stations and the latest packet for every unique position for stationary stations.
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Note:
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If no packets are found, they will be simulated.
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"""
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def __init__(self, state, db):
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"""Initialize the MostRecentPacketsQuery.
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Args:
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state (WebsocketConnectionState): The current state for a websocket connection.
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db (psycopg2.Connection): Database connection.
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"""
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self.state = state
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self.db = db
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self.packet_repository = PacketRepository(db)
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self.simulate_empty_station = False
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def enable_simulate_empty_station(self):
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"""Enable simulation even if no packets are available from the station."""
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self.simulate_empty_station = True
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def get_packets(self, station_ids):
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"""Fetch the most recent packets for the specified stations.
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Returns the latest packet for moving stations and the latest packet for every unique position for stationary stations.
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Args:
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station_ids (list): A list of station IDs for which packets are needed.
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Returns:
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list: A list of packets.
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"""
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if self.state.latest_time_travel_request is not None:
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timestamp = int(self.state.latest_time_travel_request) - (int(self.state.latest_minutes_request) * 60)
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packets = self.packet_repository.get_most_recent_confirmed_object_list_by_station_id_list_and_time_interval(
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station_ids, timestamp, self.state.latest_time_travel_request
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)
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else:
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timestamp = int(time.time()) - (int(self.state.latest_minutes_request) * 60)
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packets = self.packet_repository.get_most_recent_confirmed_object_list_by_station_id_list(
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station_ids, timestamp
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)
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if len(packets) < len(station_ids):
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# If we have no recent markers, we just send the latest that we have
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query = MissingPacketsQuery(self.state, self.db)
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if self.simulate_empty_station:
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query.enable_simulate_empty_station()
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missing_packets = query.get_missing_packets(station_ids, packets)
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if missing_packets:
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packets.extend(missing_packets)
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return packets |