playlist: Refactor run_if_locking and add tests

hlsclient/workers/playlist.py

@@ -106,17 +106,15 @@ def worker_id(self):
         return hashlib.md5(self.playlist).hexdigest()
 
     def run_if_locking(self):
-        if self.can_run():
-            self.lock.update_lock()
-            self.run()
-
-    def can_run(self):
         if self.other_is_running():
             logging.warning("Someone else acquired the lock")
             self.stop()
-        elif not self.lock.is_locked():
+            return
+        if not self.lock.is_locked():
             self.lock.acquire(timeout=self.lock_timeout)
-        return self.lock.i_am_locking()
+        if self.lock.i_am_locking():
+            self.lock.update_lock()
+            self.run()
 
     def other_is_running(self):
         other = self.lock.is_locked() and not self.lock.i_am_locking()

tests/test_worker.py

@@ -0,0 +1,66 @@
+import random
+
+from hlsclient.workers.playlist import PlaylistWorker
+
+def test_second_worker_should_see_that_other_is_running(monkeypatch):
+    stream_name = "%0x" % random.randint(0, 2**64)
+    run_calls = []
+    def fake_run(*args):
+        run_calls.append(args)
+    def fake_stop(*args):
+        pass
+
+    first = PlaylistWorker(stream_name)
+    monkeypatch.setattr(first, 'run', fake_run)
+    monkeypatch.setattr(first, 'stop', fake_stop)
+
+    first.run_if_locking()
+    assert 1 == len(run_calls)
+
+    second = PlaylistWorker(stream_name)
+    assert True == second.other_is_running()
+
+def test_lock_should_be_updated_when_run(monkeypatch):
+    stream_name = "%0x" % random.randint(0, 2**64)
+    run_calls = []
+    lock_update_calls = []
+    def fake_run(*args):
+        run_calls.append(args)
+    def fake_lock_update(*args):
+        lock_update_calls.append(args)
+    def fake_stop(*args):
+        pass
+
+    worker = PlaylistWorker(stream_name)
+    monkeypatch.setattr(worker, 'run', fake_run)
+    monkeypatch.setattr(worker, 'stop', fake_stop)
+    monkeypatch.setattr(worker.lock, 'update_lock', fake_lock_update)
+
+    worker.run_if_locking()
+    assert 1 == len(run_calls)
+    assert 1 == len(lock_update_calls)
+
+def test_worker_should_stop_if_someone_else_acquires_lock(monkeypatch):
+    stream_name = "%0x" % random.randint(0, 2**64)
+    run_calls = []
+    stop_calls = []
+    def fake_run(*args):
+        run_calls.append(args)
+    def fake_stop(*args):
+        stop_calls.append(args)
+
+    first = PlaylistWorker(stream_name)
+    monkeypatch.setattr(first, 'run', fake_run)
+    monkeypatch.setattr(first, 'stop', fake_stop)
+    first.run_if_locking()
+
+    assert 1 == len(run_calls)
+    assert 0 == len(stop_calls)
+
+    run_calls = []
+    second = PlaylistWorker(stream_name)
+    monkeypatch.setattr(second, 'run', fake_run)
+    monkeypatch.setattr(second, 'stop', fake_stop)
+    second.run_if_locking()
+    assert 0 == len(run_calls)
+    assert 1 == len(stop_calls)