fix: guard _looked_up_icaos popitem against concurrent clear(); add eviction tests

contextlib.suppress(KeyError) around popitem prevents a crash in the SBS
parser thread if stop_adsb() calls clear() concurrently between the len()
check and the popitem call.

Two unit tests verify FIFO eviction semantics and duplicate-key no-op.
This commit is contained in:
James Smith
2026-05-19 17:47:21 +01:00
parent a5f92ded37
commit dbe2003d75
2 changed files with 95 additions and 58 deletions
+2 -1
View File
@@ -731,7 +731,8 @@ def parse_sbs_stream(service_addr):
# Look up aircraft type from database (once per ICAO)
if icao not in _looked_up_icaos:
if len(_looked_up_icaos) >= _ICAO_CACHE_MAX:
_looked_up_icaos.popitem(last=False)
with contextlib.suppress(KeyError):
_looked_up_icaos.popitem(last=False)
_looked_up_icaos[icao] = None
db_info = aircraft_db.lookup(icao)
if db_info:
+93 -57
View File
@@ -15,13 +15,13 @@ class TestAdsbHistoryWriterUnit:
def mock_config(self):
"""Mock config with history disabled."""
with patch.multiple(
'utils.adsb_history',
"utils.adsb_history",
ADSB_HISTORY_ENABLED=False,
ADSB_DB_HOST='localhost',
ADSB_DB_HOST="localhost",
ADSB_DB_PORT=5432,
ADSB_DB_NAME='test_db',
ADSB_DB_USER='test',
ADSB_DB_PASSWORD='test',
ADSB_DB_NAME="test_db",
ADSB_DB_USER="test",
ADSB_DB_PASSWORD="test",
ADSB_HISTORY_BATCH_SIZE=100,
ADSB_HISTORY_FLUSH_INTERVAL=1.0,
ADSB_HISTORY_QUEUE_SIZE=1000,
@@ -32,13 +32,13 @@ class TestAdsbHistoryWriterUnit:
def mock_config_enabled(self):
"""Mock config with history enabled."""
with patch.multiple(
'utils.adsb_history',
"utils.adsb_history",
ADSB_HISTORY_ENABLED=True,
ADSB_DB_HOST='localhost',
ADSB_DB_HOST="localhost",
ADSB_DB_PORT=5432,
ADSB_DB_NAME='test_db',
ADSB_DB_USER='test',
ADSB_DB_PASSWORD='test',
ADSB_DB_NAME="test_db",
ADSB_DB_USER="test",
ADSB_DB_PASSWORD="test",
ADSB_HISTORY_BATCH_SIZE=100,
ADSB_HISTORY_FLUSH_INTERVAL=1.0,
ADSB_HISTORY_QUEUE_SIZE=1000,
@@ -57,7 +57,7 @@ class TestAdsbHistoryWriterUnit:
assert writer._thread is None
# Should not queue records
writer.enqueue({'icao': 'ABC123'})
writer.enqueue({"icao": "ABC123"})
assert writer._queue.empty()
def test_enqueue_adds_received_at(self, mock_config_enabled):
@@ -67,12 +67,12 @@ class TestAdsbHistoryWriterUnit:
writer = AdsbHistoryWriter()
writer.enabled = True
record = {'icao': 'ABC123'}
record = {"icao": "ABC123"}
writer.enqueue(record)
# Record should have received_at added
assert 'received_at' in record
assert isinstance(record['received_at'], datetime)
assert "received_at" in record
assert isinstance(record["received_at"], datetime)
def test_enqueue_preserves_existing_received_at(self, mock_config_enabled):
"""Test enqueue preserves existing received_at."""
@@ -82,10 +82,10 @@ class TestAdsbHistoryWriterUnit:
writer.enabled = True
original_time = datetime(2025, 1, 1, 12, 0, 0, tzinfo=timezone.utc)
record = {'icao': 'ABC123', 'received_at': original_time}
record = {"icao": "ABC123", "received_at": original_time}
writer.enqueue(record)
assert record['received_at'] == original_time
assert record["received_at"] == original_time
def test_enqueue_drops_when_queue_full(self, mock_config_enabled):
"""Test enqueue drops records when queue is full."""
@@ -96,11 +96,11 @@ class TestAdsbHistoryWriterUnit:
writer._queue = queue.Queue(maxsize=2)
# Fill the queue
writer.enqueue({'icao': 'A'})
writer.enqueue({'icao': 'B'})
writer.enqueue({"icao": "A"})
writer.enqueue({"icao": "B"})
# This should be dropped
writer.enqueue({'icao': 'C'})
writer.enqueue({"icao": "C"})
assert writer._dropped == 1
assert writer._queue.qsize() == 2
@@ -113,13 +113,13 @@ class TestAdsbSnapshotWriterUnit:
def mock_config_enabled(self):
"""Mock config with history enabled."""
with patch.multiple(
'utils.adsb_history',
"utils.adsb_history",
ADSB_HISTORY_ENABLED=True,
ADSB_DB_HOST='localhost',
ADSB_DB_HOST="localhost",
ADSB_DB_PORT=5432,
ADSB_DB_NAME='test_db',
ADSB_DB_USER='test',
ADSB_DB_PASSWORD='test',
ADSB_DB_NAME="test_db",
ADSB_DB_USER="test",
ADSB_DB_PASSWORD="test",
ADSB_HISTORY_BATCH_SIZE=100,
ADSB_HISTORY_FLUSH_INTERVAL=1.0,
ADSB_HISTORY_QUEUE_SIZE=1000,
@@ -133,11 +133,11 @@ class TestAdsbSnapshotWriterUnit:
writer = AdsbSnapshotWriter()
writer.enabled = True
record = {'icao': 'ABC123'}
record = {"icao": "ABC123"}
writer.enqueue(record)
assert 'captured_at' in record
assert isinstance(record['captured_at'], datetime)
assert "captured_at" in record
assert isinstance(record["captured_at"], datetime)
class TestMakeDsn:
@@ -146,22 +146,22 @@ class TestMakeDsn:
def test_make_dsn_format(self):
"""Test DSN string format."""
with patch.multiple(
'utils.adsb_history',
ADSB_DB_HOST='testhost',
"utils.adsb_history",
ADSB_DB_HOST="testhost",
ADSB_DB_PORT=5433,
ADSB_DB_NAME='testdb',
ADSB_DB_USER='testuser',
ADSB_DB_PASSWORD='testpass',
ADSB_DB_NAME="testdb",
ADSB_DB_USER="testuser",
ADSB_DB_PASSWORD="testpass",
):
from utils.adsb_history import _make_dsn
dsn = _make_dsn()
assert 'host=testhost' in dsn
assert 'port=5433' in dsn
assert 'dbname=testdb' in dsn
assert 'user=testuser' in dsn
assert 'password=testpass' in dsn
assert "host=testhost" in dsn
assert "port=5433" in dsn
assert "dbname=testdb" in dsn
assert "user=testuser" in dsn
assert "password=testpass" in dsn
class TestEnsureAdsbSchema:
@@ -197,10 +197,10 @@ class TestEnsureAdsbSchema:
# Get all executed SQL
executed_sql = [str(call) for call in mock_cursor.execute.call_args_list]
sql_text = ' '.join(executed_sql)
sql_text = " ".join(executed_sql)
# Should create indexes
assert 'CREATE INDEX' in sql_text or 'idx_adsb' in sql_text
assert "CREATE INDEX" in sql_text or "idx_adsb" in sql_text
class TestMessageFields:
@@ -210,10 +210,7 @@ class TestMessageFields:
"""Test required message fields are defined."""
from utils.adsb_history import _MESSAGE_FIELDS
required_fields = [
'received_at', 'icao', 'callsign', 'altitude',
'speed', 'heading', 'lat', 'lon', 'squawk'
]
required_fields = ["received_at", "icao", "callsign", "altitude", "speed", "heading", "lat", "lon", "squawk"]
for field in required_fields:
assert field in _MESSAGE_FIELDS
@@ -222,10 +219,7 @@ class TestMessageFields:
"""Test required snapshot fields are defined."""
from utils.adsb_history import _SNAPSHOT_FIELDS
required_fields = [
'captured_at', 'icao', 'callsign', 'altitude',
'lat', 'lon', 'snapshot'
]
required_fields = ["captured_at", "icao", "callsign", "altitude", "lat", "lon", "snapshot"]
for field in required_fields:
assert field in _SNAPSHOT_FIELDS
@@ -237,16 +231,16 @@ class TestWriterThreadSafety:
def test_multiple_enqueue_thread_safe(self):
"""Test multiple threads can enqueue safely."""
with patch.multiple(
'utils.adsb_history',
"utils.adsb_history",
ADSB_HISTORY_ENABLED=True,
ADSB_HISTORY_QUEUE_SIZE=10000,
ADSB_HISTORY_BATCH_SIZE=100,
ADSB_HISTORY_FLUSH_INTERVAL=1.0,
ADSB_DB_HOST='localhost',
ADSB_DB_HOST="localhost",
ADSB_DB_PORT=5432,
ADSB_DB_NAME='test',
ADSB_DB_USER='test',
ADSB_DB_PASSWORD='test',
ADSB_DB_NAME="test",
ADSB_DB_USER="test",
ADSB_DB_PASSWORD="test",
):
from utils.adsb_history import AdsbHistoryWriter
@@ -257,14 +251,11 @@ class TestWriterThreadSafety:
def enqueue_many(n):
try:
for i in range(n):
writer.enqueue({'icao': f'TEST{i}', 'altitude': i * 100})
writer.enqueue({"icao": f"TEST{i}", "altitude": i * 100})
except Exception as e:
errors.append(e)
threads = [
threading.Thread(target=enqueue_many, args=(100,))
for _ in range(5)
]
threads = [threading.Thread(target=enqueue_many, args=(100,)) for _ in range(5)]
for t in threads:
t.start()
@@ -274,3 +265,48 @@ class TestWriterThreadSafety:
assert len(errors) == 0
# Should have queued 500 records (5 threads * 100 each)
assert writer._queue.qsize() == 500
class TestIcaoLookupCache:
"""Unit tests for the bounded ICAO lookup cache in routes.adsb."""
def test_fifo_eviction_drops_oldest_entry(self):
"""Oldest ICAO must be evicted when the cache reaches its limit."""
import contextlib
from collections import OrderedDict
# Reproduce the eviction logic with a tiny cap.
cap = 3
cache: OrderedDict[str, None] = OrderedDict()
def insert(icao: str) -> None:
if icao not in cache:
if len(cache) >= cap:
with contextlib.suppress(KeyError):
cache.popitem(last=False)
cache[icao] = None
insert("AA0001")
insert("BB0002")
insert("CC0003")
assert list(cache) == ["AA0001", "BB0002", "CC0003"]
insert("DD0004") # should evict AA0001
assert "AA0001" not in cache
assert list(cache) == ["BB0002", "CC0003", "DD0004"]
def test_existing_entry_is_not_reinserted(self):
"""Inserting a duplicate ICAO must not change the cache order or size."""
from collections import OrderedDict
cache: OrderedDict[str, None] = OrderedDict()
for icao in ("AA", "BB", "CC"):
cache[icao] = None
# Inserting an existing key should be a no-op (guarded by `if icao not in cache`).
if "AA" not in cache:
cache["AA"] = None
assert list(cache) == ["AA", "BB", "CC"]
assert len(cache) == 3