def __compress_and_pack(self, data: bytes):
lz77_codec = LZ77Codec(256)
huffman_codec = HuffmanCodec()
checksum = huffman_codec.count_checksum(data)
codewords = lz77_codec.encode(data)
codewords_bytes = bytearray()
for codeword in codewords:
codewords_bytes.append(codeword.offset)
codewords_bytes.append(codeword.length)
codewords_bytes.append(codeword.char)
encoded_data, codes_table = \
huffman_codec.encode(bytes(codewords_bytes))
packed_data = self._pack_data(encoded_data, checksum, codes_table)
return packed_data
def test_decode(data, expected):
lz77_codec = LZ77Codec(len(data))
decoded = lz77_codec.decode(data)
assert decoded == expected
def test_decode_length_over_512():
lz77_codec = LZ77Codec(256)
data_to_encode = [Codeword(0, 0, 0), Codeword(1, 255, 0),
Codeword(2, 255, 0), Codeword(3, 41, 0)]
decoded = lz77_codec.decode(data_to_encode)
assert decoded == bytes(555)
def test_encode_length_over_512():
lz77_codec = LZ77Codec(256)
data = bytes(555)
encoded = lz77_codec.encode(data)
assert encoded == [Codeword(0, 0, 0), Codeword(1, 255, 0),
Codeword(2, 255, 0), Codeword(3, 41, 0)]
def test_encode_length_over_255():
lz77_codec = LZ77Codec(256)
data = bytes(261)
encoded = lz77_codec.encode(data)
assert encoded == [Codeword(0, 0, 0), Codeword(1, 255, 0),
Codeword(2, 3, 0)]
def test_encode(data, expected):
lz77_codec = LZ77Codec(len(data))
encoded = lz77_codec.encode(data)
assert encoded == expected