def test_buffer_fill_size_return(self):
'''
Test that buffer fill size is
correctly returned under various
use scenarios
'''
# Test that buffer fill size is returned as
# 0 when buffer is empty
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
fill_size = buffer.get_buffer_fill()
self.assertEqual(fill_size, 0)
# Test that buffer fill size is returned as
# the number of elements pushed when the
# buffer is neither empty nor full
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
for i in range(0, int(random_size / 2)):
buffer.push(i)
fill_size = buffer.get_buffer_fill()
self.assertEqual(fill_size, int(random_size / 2))
# Test that buffer fill size is correctly
# returned when buffer is full
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
for i in range(0, random_size):
buffer.push(i)
fill_size = buffer.get_buffer_fill()
self.assertEqual(fill_size, random_size)
def run_consumer(name, delay):
buffer = RingBuffer(name=name, size=0, create=False)
shutdown = False
def terminate(signum, frame):
nonlocal shutdown
print(
"Received=",
signal.Signals(signum).name,
"Attempting graceful shutdown of consumer",
)
shutdown = True
signal.signal(signal.SIGTERM, terminate)
signal.signal(signal.SIGINT, terminate)
try:
while not shutdown:
b = buffer.get()
print(f"Message: {decode_message(b)}Reader: {buffer.reader_pos()} Writer: {buffer.writer_pos()}")
time.sleep(delay)
buffer.close()
print(f"Destroyed shared memory buffer {name}")
except Exception as ex:
buffer.close()
print(f"Error {str(ex)}. Destroying shared memory buffer and exiting")
traceback.print_exc(file=sys.stdout)
sys.exit(1)
def test_push(self):
'''
Test that buffer push works
'''
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
buffer.push(0)
def test_attach_with_existing_buffer(buffer):
new_buff = RingBuffer(name=buffer.name, size=0, create=False)
assert new_buff.data_buff.name == "test"
assert len(new_buff.data_buff.buf) == 100
assert new_buff.write_index_buff.name == "test-writer"
assert len(new_buff.write_index_buff.buf) == WRITE_INDEX_BUFFER_SIZE
assert new_buff.read_index_buff.name == "test-reader"
assert len(new_buff.read_index_buff.buf) == READ_INDEX_BUFFER_SIZE
def test_pop(self):
'''
Test that buffer pop returns pushed value
'''
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
buffer.push(0)
returned_element = buffer.pop()
self.assertEqual(returned_element, 0)
def test_reader_reads_data_and_moves_offset(buffer):
read_buff = RingBuffer(name=buffer.name, size=0, create=False)
messages = _messages(3)
expected = [_decode_message(m) for m in messages]
for m in messages:
buffer.put(m)
got = [_decode_message(read_buff.get()) for _ in range(3)]
assert got == expected
assert read_buff.reader_pos() == 48
def test_initialize_params(self):
'''
Test that buffer init params are returned
correctly
'''
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
self.assertEqual(buffer.get_capacity(), random_size)
self.assertFalse(buffer.is_full())
self.assertTrue(buffer.is_empty())
self.assertEqual(buffer.get_buffer_fill(), 0)
def test_pop_empty_fail(self):
'''
Test that popping from an empty buffer
results in RuntimeException being raised
along with "Buffer empty" exception message
'''
with pytest.raises(RuntimeError) as excinfo:
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
buffer.pop()
self.assertEqual(str(excinfo.value), 'Buffer is empty!')
def test_get_capacity(self):
'''
Test that get_capacity method
returns correct values
'''
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
for i in range(0, random.randrange(1, random_size)):
buffer.push(i)
buffer_capacity = buffer.get_capacity()
self.assertEqual(buffer_capacity, random_size)
def test_reader_does_not_go_past_writer(buffer):
read_buff = RingBuffer(name=buffer.name, size=0, create=False)
messages = _messages(3)
for m in messages:
buffer.put(m)
with pytest.raises(WriterCollisionError) as excinfo:
[read_buff.get() for _ in range(5)]
assert str(
excinfo.value
) == "Writer cursor at 48. Reader cursor attemping to read [48 :64]"
def test_push_full_fail(self):
'''
Test that pushing into a full
buffer raises Runtime Exception
and the "buffer full" message
'''
with pytest.raises(RuntimeError) as excinfo:
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
for i in range(0, random_size + 1):
buffer.push(i)
self.assertEqual(str(excinfo.value), 'Buffer is full!')
def test_clear(self):
'''
Test that clear() method clears
the buffer properly
'''
random_size = random.randrange(1, 100)
buffer = RingBuffer(random_size)
for i in range(0, random.randrange(1, random_size)):
buffer.push(i)
buffer.clear()
self.assertTrue(buffer.is_empty())
self.assertFalse(buffer.is_full())
self.assertEqual(buffer.get_capacity(), random_size)
self.assertEqual(buffer.get_buffer_fill(), 0)
def test_reader_reads_data_and_moves_offset_when_writer_wraps_around(buffer):
read_buff = RingBuffer(name=buffer.name, size=0, create=False)
messages = _messages(8)
for m in messages[:6]:
buffer.put(m)
[read_buff.get() for _ in range(6)]
for m in messages[6:]:
buffer.put(m)
got = [_decode_message(read_buff.get()) for _ in range(2)]
expected = [_decode_message(m) for m in messages[6:]]
assert got == expected
assert read_buff.reader_pos() == 32
def test_reader_does_not_go_past_writer_when_writer_wraps_around(buffer):
read_buff = RingBuffer(name=buffer.name, size=0, create=False)
messages = _messages(8)
for m in messages[:6]:
buffer.put(m)
[read_buff.get() for _ in range(6)]
for m in messages[6:7]:
buffer.put(m)
with pytest.raises(WriterCollisionError) as excinfo:
[read_buff.get() for _ in range(2)]
assert str(
excinfo.value
) == "Writer cursor at 16. Reader cursor attemping to read [16 :32]"
def setUp(self):
self.capacity = 5
self.buffer = RingBuffer(self.capacity)
def create_buffer():
buff = RingBuffer(name="test", size=100, create=True)
yield buff
buff.destroy()