Files
full-stack-fastapi/backend/app/mqtt/parser_worker.py

73 lines
2.1 KiB
Python

from __future__ import annotations
import logging
import time
from datetime import timedelta
from sqlmodel import Session
from app.core.config import settings
from app.core.db import engine
from app.models import TerminalMessageRaw, get_datetime_utc
from app.mqtt.parsers.mixed import parse_mixed_payload
from app.mqtt.repository import (
fetch_pending_rows_for_update,
mark_failed,
mark_processing,
mark_succeeded,
write_events_and_update_state,
)
logger = logging.getLogger(__name__)
def _next_retry_delay_seconds(attempts: int) -> int:
# Bounded exponential backoff: 30s, 60s, 120s, ... capped to 15m.
return int(min(30 * (2 ** max(attempts - 1, 0)), 900))
def _process_one_row(*, session: Session, row: TerminalMessageRaw) -> None:
mark_processing(session=session, row=row)
session.commit()
try:
events = parse_mixed_payload(row.payload_bytes)
write_events_and_update_state(session=session, row=row, events=events)
mark_succeeded(session=session, row=row)
except Exception as exc: # pragma: no cover - safety net path
delay = _next_retry_delay_seconds(row.parse_attempts)
mark_failed(
session=session,
row=row,
parse_error=str(exc),
next_retry_at=get_datetime_utc() + timedelta(seconds=delay),
)
session.commit()
def process_pending_batch(*, session: Session, batch_size: int) -> int:
rows = fetch_pending_rows_for_update(session=session, batch_size=batch_size)
for row in rows:
_process_one_row(session=session, row=row)
return len(rows)
def run() -> None:
logging.basicConfig(level=logging.INFO)
sleep_seconds = max(settings.PARSER_POLL_INTERVAL_MS, 50) / 1000.0
while True:
with Session(engine) as session:
processed = process_pending_batch(
session=session, batch_size=settings.PARSER_BATCH_SIZE
)
if processed == 0:
time.sleep(sleep_seconds)
else:
logger.info("Processed %s pending MQTT raw messages", processed)
if __name__ == "__main__":
run()