Files
sentiment-engine/MALKHUT/malkhut/clock/staleness.py
Codex 316d01079b malkhut(T7): UV Clock — event-driven reactor + staleness watchdog
UVClock (clock/host.py): T19 event-driven reactor, asyncio dispatch.
Events (clock/events.py): Scan, Tick, Timer, BarFire, Stale.
Staleness watchdog (clock/staleness.py): T19 Staleness Law enforcement.
DeadNode reaper (clock/deadnode.py): iox2 orphan sweep on startup.
2026-07-11 10:36:30 +02:00

108 lines
3.2 KiB
Python

"""
T19 Staleness Watchdog — freshness monitor for event sources.
Per T19 ANNEX A Staleness Law:
1. BarFire is EDGE-TRIGGERED on scan_number monotonic advance — NEVER timer-synthesized.
2. Every event carries provenance: scan_number, scan_ts, ingest_ts, AGE at dispatch.
3. Freshness watchdog TimerEvent (now - last_scan_ts > 1.5x cadence) emits StaleInput.
This is the June-22 scan-freeze / silent-scanner-death detector, native.
Fixes BLUE's oldest observability hole as a side effect.
"""
from __future__ import annotations
import time
from typing import Callable, Optional
from malkhut.clock.events import EventProvenance, StaleInput, TimerEvent
class StalenessWatchdog:
"""
Monitors event source freshness. Emits StaleInput when stale.
Usage:
watchdog = StalenessWatchdog(cadence_ns=5_850_000_000)
# On each event:
watchdog.heartbeat(provenance)
# Periodically (via TimerEvent):
stale = watchdog.check()
if stale:
# TUI red + posture response
"""
def __init__(
self,
cadence_ns: int = 5_850_000_000, # 5.85s default
stale_factor: float = 1.5,
on_stale: Optional[Callable[[StaleInput], None]] = None,
) -> None:
self._cadence_ns = cadence_ns
self._stale_factor = stale_factor
self._stale_threshold_ns = int(cadence_ns * stale_factor)
self._on_stale = on_stale
self._last_scan_ts: int = 0
self._last_scan_number: int = -1
self._is_stale: bool = False
self._stale_count: int = 0
def heartbeat(self, provenance: EventProvenance) -> None:
"""Record a fresh event. Resets staleness."""
now = time.time_ns()
self._last_scan_ts = provenance.scan_ts
self._last_scan_number = provenance.scan_number
if self._is_stale:
# Recovery from stale state
self._is_stale = False
def check(self) -> Optional[StaleInput]:
"""
Check if source is stale. Returns StaleInput if stale, None if fresh.
Call this from a TimerEvent handler at the watchdog cadence.
"""
now = time.time_ns()
age = now - self._last_scan_ts if self._last_scan_ts > 0 else now
if age > self._stale_threshold_ns and not self._is_stale:
self._is_stale = True
self._stale_count += 1
stale = StaleInput(
source="scan_source",
last_scan_ts=self._last_scan_ts,
current_ts=now,
stale_duration_ns=age - self._stale_threshold_ns,
)
if self._on_stale:
self._on_stale(stale)
return stale
return None
@property
def is_stale(self) -> bool:
return self._is_stale
@property
def stale_count(self) -> int:
return self._stale_count
@property
def last_scan_ts(self) -> int:
return self._last_scan_ts
@property
def last_scan_number(self) -> int:
return self._last_scan_number
@property
def age_ns(self) -> int:
if self._last_scan_ts == 0:
return time.time_ns()
return time.time_ns() - self._last_scan_ts