def test_oh_tail_large(tag, key, data):
"""Compare OH compression for the last block, when it has enough data
to fully contain the last 16-byte chunk."""
expected = oh_compress_one_block(key, split_block(data), tag << 64)
n_bytes = len(data)
# Copy to exactly-sized malloced buffers to help ASan.
block = FFI.new("char[]", n_bytes)
FFI.memmove(block, data, n_bytes)
params = FFI.new("struct umash_params[1]")
for i, param in enumerate(key):
params[0].oh[i] = param
actual = C.oh_last_block(params[0].oh, tag, block, n_bytes)
assert expected == actual.bits[0] + (actual.bits[1] << 64), (
actual.bits[0],
actual.bits[1],
)
def test_oh_tail_short(tag, key, prefix, data):
"""Compare OH compression for the last block, when we must steal some
data from the previous chunk."""
expected = oh_compress_one_block(
key, split_block(prefix * (C.UMASH_OH_PARAM_COUNT // 2) + data),
tag << 64)
offset = len(prefix)
n_bytes = len(data)
# Copy to exactly-sized malloced buffers to help ASan.
block = FFI.new("char[]", offset + n_bytes)
FFI.memmove(block, prefix + data, offset + n_bytes)
params = FFI.new("struct umash_params[1]")
for i, param in enumerate(key):
params[0].oh[i] = param
actual = C.oh_last_block(params[0].oh, tag, block + offset, n_bytes)
assert expected == actual.bits[0] + (actual.bits[1] << 64), (
actual.bits[0],
actual.bits[1],
)
