Files
pyMC_Repeater/tests/test_packet_router.py

329 lines
10 KiB
Python

"""
Tests for PacketRouter in-flight cap and shutdown behaviour.
Addresses the three concerns raised in PR 191 review:
1. Cap enforcement: packets beyond _max_in_flight are dropped, not queued.
2. Drop counter: _cap_drop_count increments on each cap-drop so operators
have visibility into how often the safety valve fires.
3. Shutdown drain: stop() waits for in-flight tasks to finish (up to 5 s),
then cancels any that remain — tasks are never silently abandoned.
Run with:
python -m pytest tests/test_packet_router.py -v
or:
python -m unittest tests.test_packet_router -v
"""
import asyncio
import time
import unittest
from unittest.mock import AsyncMock, MagicMock, patch
from pymc_core.node.handlers.trace import TraceHandler
from repeater.packet_router import PacketRouter
# ---------------------------------------------------------------------------
# Minimal daemon stub
# ---------------------------------------------------------------------------
def _make_daemon():
"""Minimal daemon that satisfies PacketRouter without touching hardware."""
daemon = MagicMock()
daemon.repeater_handler = AsyncMock(return_value=None)
daemon.trace_helper = None
daemon.discovery_helper = None
daemon.advert_helper = None
daemon.companion_bridges = {}
daemon.login_helper = None
daemon.text_helper = None
daemon.path_helper = None
daemon.protocol_request_helper = None
return daemon
def _make_packet(payload_type: int = 0xFF):
"""Minimal packet stub."""
pkt = MagicMock()
pkt.get_payload_type.return_value = payload_type
pkt.payload = b"\xff"
pkt.header = 0x00
pkt.rssi = -80
pkt.snr = 5.0
pkt.timestamp = time.time()
pkt._injected_for_tx = False
pkt.path = bytearray()
return pkt
# ---------------------------------------------------------------------------
# Tests
# ---------------------------------------------------------------------------
class TestInFlightCap(unittest.IsolatedAsyncioTestCase):
# ── 1. Cap enforcement ──────────────────────────────────────────────────
async def test_cap_drops_packets_when_full(self):
"""
When _in_flight reaches _max_in_flight, new packets from the queue
must be dropped (not passed to _route_packet).
"""
router = PacketRouter(_make_daemon())
router._max_in_flight = 3
# Manually occupy all slots with long-sleeping tasks
barrier = asyncio.Event()
async def slow_route(pkt):
await barrier.wait() # blocks until we release
routed = []
async def counting_route(pkt):
routed.append(pkt)
await barrier.wait()
router._route_packet = counting_route
await router.start()
# Fill the cap
for _ in range(3):
await router.enqueue(_make_packet())
await asyncio.sleep(0.05) # let queue drain into tasks
self.assertEqual(router._in_flight, 3)
# These should be dropped
for _ in range(5):
await router.enqueue(_make_packet())
await asyncio.sleep(0.05)
self.assertEqual(router._in_flight, 3,
"In-flight count exceeded cap")
self.assertEqual(router._cap_drop_count, 5,
"Expected 5 cap-drops, got different count")
barrier.set() # release blocked tasks
await router.stop()
# ── 2. Drop counter ─────────────────────────────────────────────────────
async def test_cap_drop_count_increments(self):
"""_cap_drop_count must increment by exactly 1 for each dropped packet."""
router = PacketRouter(_make_daemon())
router._max_in_flight = 1
barrier = asyncio.Event()
async def blocking_route(pkt):
await barrier.wait()
router._route_packet = blocking_route
await router.start()
# Fill the single slot
await router.enqueue(_make_packet())
await asyncio.sleep(0.05)
self.assertEqual(router._in_flight, 1)
# Drop three packets
for _ in range(3):
await router.enqueue(_make_packet())
await asyncio.sleep(0.05)
self.assertEqual(router._cap_drop_count, 3)
barrier.set()
await router.stop()
async def test_cap_drop_count_zero_when_cap_not_reached(self):
"""_cap_drop_count must stay 0 when the cap is never reached."""
router = PacketRouter(_make_daemon())
router._max_in_flight = 30
completed = []
async def fast_route(pkt):
completed.append(pkt)
router._route_packet = fast_route
await router.start()
for _ in range(10):
await router.enqueue(_make_packet())
await asyncio.sleep(0.1)
self.assertEqual(router._cap_drop_count, 0)
await router.stop()
async def test_injected_trace_packet_skips_inbound_trace_processing(self):
"""Locally injected TRACE packets must not be re-parsed as inbound trace responses."""
daemon = _make_daemon()
daemon.trace_helper = MagicMock()
daemon.trace_helper.process_trace_packet = AsyncMock()
router = PacketRouter(daemon)
pkt = _make_packet(payload_type=TraceHandler.payload_type())
await router.start()
try:
injected = await router.inject_packet(pkt)
self.assertTrue(injected)
await asyncio.sleep(0.05)
daemon.repeater_handler.assert_awaited_once()
daemon.trace_helper.process_trace_packet.assert_not_awaited()
finally:
await router.stop()
# ── 3. Shutdown: in-flight tasks drained ────────────────────────────────
async def test_stop_waits_for_in_flight_tasks(self):
"""
stop() must wait for in-flight tasks to complete before returning.
Tasks that finish within the 5-second timeout must complete normally,
not be cancelled.
"""
router = PacketRouter(_make_daemon())
completed = []
started = asyncio.Event()
async def slow_route(pkt):
started.set()
await asyncio.sleep(0.2) # finishes well within 5 s timeout
completed.append(pkt)
router._route_packet = slow_route
await router.start()
pkt = _make_packet()
await router.enqueue(pkt)
# Wait until the task has actually started
await asyncio.wait_for(started.wait(), timeout=1.0)
await router.stop()
# Task should have completed, not been cancelled
self.assertEqual(len(completed), 1,
"In-flight task was cancelled instead of drained")
async def test_stop_cancels_tasks_that_exceed_timeout(self):
"""
Tasks that don't finish within the 5-second timeout must be cancelled,
not left running indefinitely.
"""
router = PacketRouter(_make_daemon())
router._max_in_flight = 5
cancelled = []
started = asyncio.Event()
async def hanging_route(pkt):
started.set()
try:
await asyncio.sleep(999) # will not finish within 5 s
except asyncio.CancelledError:
cancelled.append(pkt)
raise
router._route_packet = hanging_route
# Patch the timeout to 0.1 s so the test runs fast
original_stop = router.stop
async def fast_stop():
router.running = False
if router.router_task:
router.router_task.cancel()
try:
await router.router_task
except asyncio.CancelledError:
pass
if router._route_tasks:
snapshot = set(router._route_tasks)
_, still_pending = await asyncio.wait(snapshot, timeout=0.1)
for task in still_pending:
task.cancel()
await asyncio.gather(*still_pending, return_exceptions=True)
router.stop = fast_stop
await router.start()
await router.enqueue(_make_packet())
await asyncio.wait_for(started.wait(), timeout=1.0)
await router.stop()
self.assertEqual(len(cancelled), 1,
"Hanging task was not cancelled on shutdown")
# ── 4. Route-tasks set stays in sync with counter ───────────────────────
async def test_route_tasks_set_cleaned_up_on_completion(self):
"""
_route_tasks must be empty after all tasks complete — the done-callback
must discard each task so the set doesn't grow unboundedly.
"""
router = PacketRouter(_make_daemon())
async def fast_route(pkt):
await asyncio.sleep(0) # yield, then done
router._route_packet = fast_route
await router.start()
for _ in range(10):
await router.enqueue(_make_packet())
# Give tasks time to complete
await asyncio.sleep(0.1)
self.assertEqual(len(router._route_tasks), 0,
"_route_tasks not cleaned up after task completion")
self.assertEqual(router._in_flight, 0,
"_in_flight counter not back to 0 after completion")
await router.stop()
# ── 5. Counter and set always agree ─────────────────────────────────────
async def test_counter_matches_set_size_under_load(self):
"""
_in_flight must always equal len(_route_tasks) while tasks are running.
Checked at steady state when the cap is saturated.
"""
router = PacketRouter(_make_daemon())
router._max_in_flight = 5
barrier = asyncio.Event()
async def blocking_route(pkt):
await barrier.wait()
router._route_packet = blocking_route
await router.start()
for _ in range(5):
await router.enqueue(_make_packet())
await asyncio.sleep(0.05)
self.assertEqual(
router._in_flight, len(router._route_tasks),
f"Counter ({router._in_flight}) != set size ({len(router._route_tasks)})"
)
barrier.set()
await router.stop()
if __name__ == "__main__":
unittest.main()