# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2023 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
import datetime
import sqlalchemy as sa
from lvestats.orm import bursting_events_table
class TableDoesNotExistError(Exception):
def __init__(self, table_name):
self.message = f'Table "{table_name}" does not exist in the database'
super().__init__(self.message)
class HistoryShowBursting:
def __init__(self,
dbengine: sa.engine.base.Engine,
period_from: datetime.datetime,
period_to: datetime.datetime,
uid: int | None = None,
server_id: str = 'localhost') -> None:
self.dbengine = dbengine
self.period_from = period_from
self.period_to = period_to
self.uid = uid
self.server_id = server_id
def get(self) -> list[sa.engine.RowProxy]:
"""
Get history from the 'bursting_events' table.
Retrieving records within the required time frame,
along with one record preceding this time frame
to detect the bursting status at the start of the time frame.
"""
# Since bursting limits functionality isn't enabled by default,
# we need to check if the table exists first
inspector = sa.inspect(self.dbengine)
if bursting_events_table.name not in inspector.get_table_names():
raise TableDoesNotExistError(bursting_events_table.name)
ts_from = self.period_from.timestamp()
ts_to = self.period_to.timestamp()
# Get the rows with timestamp between ts_from and ts_to
stmt1 = sa.select([
bursting_events_table.c.lve_id,
bursting_events_table.c.timestamp,
bursting_events_table.c.event_type,
]).where(
sa.and_(
bursting_events_table.c.server_id == self.server_id,
bursting_events_table.c.timestamp >= ts_from,
bursting_events_table.c.timestamp <= ts_to,
# Add lve_id condition if it's specified
(bursting_events_table.c.lve_id == self.uid) if self.uid is not None else True,
)
)
# Subquery to get the maximum timestamp for each lve_id where timestamp < ts_from
subquery = sa.select([
bursting_events_table.c.lve_id,
sa.func.max(bursting_events_table.c.timestamp).label('max_timestamp'),
]).where(
sa.and_(
bursting_events_table.c.server_id == self.server_id,
bursting_events_table.c.timestamp < ts_from,
# Add lve_id condition if it's specified
(bursting_events_table.c.lve_id == self.uid) if self.uid is not None else True,
)
).group_by(
bursting_events_table.c.lve_id,
).alias('subquery')
# Get the row with the maximum timestamp less than ts_from
stmt2 = sa.select([
bursting_events_table.c.lve_id,
bursting_events_table.c.timestamp,
bursting_events_table.c.event_type,
]).select_from(
bursting_events_table.join(
subquery,
sa.and_(
bursting_events_table.c.lve_id == subquery.c.lve_id,
bursting_events_table.c.timestamp == subquery.c.max_timestamp,
)
)
)
stmt = sa.union(
stmt1,
stmt2,
)
stmt = stmt.order_by(
stmt.c.lve_id,
stmt.c.timestamp,
)
with self.dbengine.connect() as connection:
result = connection.execute(stmt).fetchall()
return result
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