1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
# gzip-like LZSS compressor
# Copyright (C) 2018 Pacien TRAN-GIRARD
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
import unittest, streams
import bitio/bitwriter, bitio/bitreader
import lzss/lzssnode
import huffman/huffmantree, huffman/huffmandecoder
import lzsshuffman/lzsshuffmansymbol, lzsshuffman/lzsshuffmandecoder
suite "lzsshuffmandecoder":
test "readChain (empty)":
let symbolTree = huffmanLeaf(endSymbol.uint16)
let positionTree = huffmanLeaf(0'u16)
let stream = newStringStream()
defer: stream.close()
stream.write(0'u8) # eof
stream.setPosition(0)
let bitReader = stream.bitReader()
let result = readChain(bitReader, symbolTree.decoder(), positionTree.decoder(), 32_000)
check result.len == 0
test "readChain (minimal)":
let symbolTree = huffmanBranch(
huffmanBranch(
huffmanLeaf(0'u16),
huffmanLeaf(1'u16)),
huffmanBranch(
huffmanLeaf(257'u16),
huffmanBranch(
huffmanLeaf(2'u16),
huffmanLeaf(256'u16))))
let positionTree = huffmanBranch(
huffmanLeaf(3'u16),
huffmanLeaf(4'u16))
let stream = newStringStream()
defer: stream.close()
let bitWriter = stream.bitWriter()
bitWriter.writeBits(2, 0b00'u8)
bitWriter.writeBits(2, 0b10'u8)
bitWriter.writeBits(3, 0b011'u8)
bitWriter.writeBits(2, 0b01'u8)
bitWriter.writeBits(1, 0b0'u8)
bitWriter.writeBits(2, 0b01'u8)
bitWriter.writeBits(1, 0b1'u8)
bitWriter.writeBits(3, 0b111'u8)
bitWriter.flush()
stream.setPosition(0)
let bitReader = stream.bitReader()
let result = readChain(bitReader, symbolTree.decoder(), positionTree.decoder(), 32_000)
check result == [
lzssCharacter(0), lzssCharacter(1), lzssCharacter(2),
lzssReference(3, 3), lzssReference(3, 4)]
|