Files
intrusion-detection/app/scan/scan_state.py
T

34 lines
1.1 KiB
Python

#!/usr/bin/env python3
"""Persistent state for incremental log scanning.
Tracks the last processed byte offset per absolute log file path so a scan
only reads new entries instead of re-reading the whole file. The state file
is written atomically (temp file + rename) to avoid corruption.
"""
from __future__ import annotations
import json
import os
from ..utils.constants import SCAN_STATE_PATH
def load_state() -> dict[str, int]:
"""Return ``{absolute log path: byte offset}`` from the scan-state file."""
try:
with open(SCAN_STATE_PATH, "r", encoding="utf-8") as f:
data = json.load(f)
return {k: int(v) for k, v in data.items()}
except (OSError, ValueError, TypeError):
return {}
def save_state(state: dict[str, int]) -> None:
"""Write the scan-state file atomically (temp file + rename)."""
os.makedirs(os.path.dirname(SCAN_STATE_PATH), exist_ok=True)
tmp = SCAN_STATE_PATH + ".tmp"
with open(tmp, "w", encoding="utf-8") as f:
json.dump(state, f, indent=2, sort_keys=True)
os.replace(tmp, SCAN_STATE_PATH)