def items_to_bytes(self, items, descriptors=None, max_packet_size=1500):
if descriptors is None:
descriptors = items
heap = send.Heap(self)
for descriptor in descriptors:
heap.add_descriptor(descriptor)
for item in items:
heap.add_item(item)
gen = send.PacketGenerator(heap, 0x123456, max_packet_size)
return list(gen)
def test_lifetime(self):
"""Heap must hold references to item values"""
item = spead2.Item(id=0x2345, name='name', description='description',
shape=(2, 3), dtype=np.uint16)
item.value = np.array([[6, 7, 8], [10, 11, 12000]], dtype=np.uint16)
weak = weakref.ref(item.value)
heap = send.Heap(self.flavour)
heap.add_item(item)
del item
packets = list(send.PacketGenerator(heap, 0x123456, 1472)) # noqa: F841
assert weak() is not None
del heap
# pypy needs multiple gc passes to wind it all up
for i in range(10):
gc.collect()
assert weak() is None
def test_lifetime(self):
"""Heap must hold references to item values"""
item = spead2.Item(id=0x2345,
name='name',
description='description',
shape=(2, 3),
dtype=np.uint16)
item.value = np.array([[6, 7, 8], [10, 11, 12000]], dtype=np.uint16)
weak = weakref.ref(item.value)
heap = send.Heap(self.flavour)
heap.add_item(item)
del item
packets = list(send.PacketGenerator(heap, 0x123456, 1472))
assert_is_not_none(weak())
del heap
assert_is_none(weak())
def test_end(self):
"""Tests sending an end-of-stream marker."""
expected = [
b''.join([
self.flavour.make_header(6),
self.flavour.make_immediate(spead2.HEAP_CNT_ID, 0x123456),
self.flavour.make_immediate(spead2.HEAP_LENGTH_ID, 1),
self.flavour.make_immediate(spead2.PAYLOAD_OFFSET_ID, 0),
self.flavour.make_immediate(spead2.PAYLOAD_LENGTH_ID, 1),
self.flavour.make_immediate(spead2.STREAM_CTRL_ID, spead2.CTRL_STREAM_STOP),
self.flavour.make_address(spead2.NULL_ID, 0),
struct.pack('B', 0)
])
]
heap = send.Heap(self.flavour)
heap.add_end()
packet = list(send.PacketGenerator(heap, 0x123456, 1500))
assert hexlify(packet) == hexlify(expected)
def test_zero_copy(self):
"""Test that heaps can reference original data.
This allows heaps to be updated by just changing the data.
"""
id = 0x2345
data = np.arange(8, dtype=np.uint8)
imm = np.zeros((), dtype='>u8')
item1 = spead2.Item(id=id, name='item1', description='addressed item',
shape=data.shape, dtype=data.dtype, value=data)
item2 = spead2.Item(id=id + 1, name='item2', description='inline item',
shape=(), format=[('u', self.flavour.heap_address_bits)],
value=imm)
heap = spead2.send.Heap(self.flavour)
heap.add_item(item1)
heap.add_item(item2)
# Now change the values after they've been added to the heap.
data *= 2
imm[()] = 0xdeadbeef
expected = [
b''.join([
self.flavour.make_header(6),
self.flavour.make_immediate(spead2.HEAP_CNT_ID, 0x123456),
self.flavour.make_immediate(spead2.HEAP_LENGTH_ID, 8),
self.flavour.make_immediate(spead2.PAYLOAD_OFFSET_ID, 0),
self.flavour.make_immediate(spead2.PAYLOAD_LENGTH_ID, 8),
self.flavour.make_address(id, 0),
self.flavour.make_immediate(id + 1, 0xdeadbeef),
data.tobytes()
])
]
gen = send.PacketGenerator(heap, 0x123456, 1500)
packets = list(gen)
assert hexlify(packets) == hexlify(expected)
