trackdirect2/server/trackdirect/database/PacketOgnTableCreator.py

85 lines
3.2 KiB
Python

import logging
import psycopg2
import psycopg2.extras
import datetime
import time
from server.trackdirect.database.DatabaseObjectFinder import DatabaseObjectFinder
from server.trackdirect.exceptions.TrackDirectMissingTableError import TrackDirectMissingTableError
class PacketOgnTableCreator:
"""The PacketOgnTableCreator class handles packet OGN table name logic
Note:
Packets are stored in different tables depending on what day they are received,
new packet tables are created by this class.
"""
def __init__(self, db):
"""The __init__ method.
Args:
db (psycopg2.Connection): Database connection
"""
self.db = db
self.dbObjectFinder = DatabaseObjectFinder(db)
self.logger = logging.getLogger('trackdirect')
self.createIfMissing = True
def disable_create_if_missing(self):
"""Disable feature that creates new tables if missing
"""
self.createIfMissing = False
def get_table(self, packet_timestamp):
"""Returns the name of the OGN packet table
Args:
packet_timestamp (int): Unix timestamp that we need the table for
Returns:
the name of the OGN packet table as a string
"""
date = datetime.datetime.utcfromtimestamp(packet_timestamp).strftime('%Y%m%d')
packet_ogn_table = f'packet{date}_ogn'
if not self.dbObjectFinder.check_table_exists(packet_ogn_table):
if self.createIfMissing:
min_timestamp = packet_timestamp // (24 * 60 * 60) * (24 * 60 * 60)
max_timestamp = min_timestamp + (24 * 60 * 60)
self._create_table(packet_ogn_table, min_timestamp, max_timestamp)
self.dbObjectFinder.set_table_exists(packet_ogn_table)
else:
raise TrackDirectMissingTableError('Database table does not exist')
return packet_ogn_table
def _create_table(self, table_name, min_timestamp, max_timestamp):
"""Create a packet OGN table with the specified name
Args:
table_name (str): Name of the packet OGN table to create
min_timestamp (int): Min Unix timestamp for this table
max_timestamp (int): Max Unix timestamp for this table
"""
try:
cur = self.db.cursor()
sql_statements = [
f"CREATE TABLE {table_name} () INHERITS (packet_ogn)",
f"ALTER TABLE {table_name} ADD CONSTRAINT timestamp_range_check CHECK (timestamp >= {min_timestamp} AND timestamp < {max_timestamp})",
f"CREATE INDEX {table_name}_pkey ON {table_name} USING btree (id)",
f"CREATE INDEX {table_name}_packet_id_idx ON {table_name} (packet_id)",
f"CREATE INDEX {table_name}_station_id_idx ON {table_name} (station_id, timestamp)"
]
for sql in sql_statements:
cur.execute(sql)
cur.close()
except (psycopg2.IntegrityError, psycopg2.ProgrammingError) as e:
if 'already exists' not in str(e):
self.logger.error(e, exc_info=1)
time.sleep(10)
except Exception as e:
self.logger.error(e, exc_info=1)
time.sleep(10)