jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020-2021, the SerenityOS developers.
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <LibTest/TestCase.h>
8
9#include <AK/Array.h>
10#include <AK/BitStream.h>
11#include <AK/MemoryStream.h>
12#include <AK/Random.h>
13#include <LibCompress/Deflate.h>
14#include <cstring>
15
16TEST_CASE(canonical_code_simple)
17{
18 Array<u8, 32> const code {
19 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
20 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
21 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05
22 };
23 Array<u8, 6> const input {
24 0x00, 0x42, 0x84, 0xa9, 0xb0, 0x15
25 };
26 Array<u32, 9> const output {
27 0x00, 0x01, 0x01, 0x02, 0x03, 0x05, 0x08, 0x0d, 0x15
28 };
29
30 auto const huffman = Compress::CanonicalCode::from_bytes(code).value();
31 auto memory_stream = MUST(try_make<FixedMemoryStream>(input));
32 LittleEndianInputBitStream bit_stream { move(memory_stream) };
33
34 for (size_t idx = 0; idx < 9; ++idx)
35 EXPECT_EQ(MUST(huffman.read_symbol(bit_stream)), output[idx]);
36}
37
38TEST_CASE(canonical_code_complex)
39{
40 Array<u8, 6> const code {
41 0x03, 0x02, 0x03, 0x03, 0x02, 0x03
42 };
43 Array<u8, 4> const input {
44 0xa1, 0xf3, 0xa1, 0xf3
45 };
46 Array<u32, 12> const output {
47 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05
48 };
49
50 auto const huffman = Compress::CanonicalCode::from_bytes(code).value();
51 auto memory_stream = MUST(try_make<FixedMemoryStream>(input));
52 LittleEndianInputBitStream bit_stream { move(memory_stream) };
53
54 for (size_t idx = 0; idx < 12; ++idx)
55 EXPECT_EQ(MUST(huffman.read_symbol(bit_stream)), output[idx]);
56}
57
58TEST_CASE(deflate_decompress_compressed_block)
59{
60 Array<u8, 28> const compressed {
61 0x0B, 0xC9, 0xC8, 0x2C, 0x56, 0x00, 0xA2, 0x44, 0x85, 0xE2, 0xCC, 0xDC,
62 0x82, 0x9C, 0x54, 0x85, 0x92, 0xD4, 0x8A, 0x12, 0x85, 0xB4, 0x4C, 0x20,
63 0xCB, 0x4A, 0x13, 0x00
64 };
65
66 const u8 uncompressed[] = "This is a simple text file :)";
67
68 auto const decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
69 EXPECT(decompressed.value().bytes() == ReadonlyBytes({ uncompressed, sizeof(uncompressed) - 1 }));
70}
71
72TEST_CASE(deflate_decompress_uncompressed_block)
73{
74 Array<u8, 18> const compressed {
75 0x01, 0x0d, 0x00, 0xf2, 0xff, 0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20,
76 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x21
77 };
78
79 const u8 uncompressed[] = "Hello, World!";
80
81 auto const decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
82 EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
83}
84
85TEST_CASE(deflate_decompress_multiple_blocks)
86{
87 Array<u8, 84> const compressed {
88 0x00, 0x1f, 0x00, 0xe0, 0xff, 0x54, 0x68, 0x65, 0x20, 0x66, 0x69, 0x72,
89 0x73, 0x74, 0x20, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x20, 0x69, 0x73, 0x20,
90 0x75, 0x6e, 0x63, 0x6f, 0x6d, 0x70, 0x72, 0x65, 0x73, 0x73, 0x65, 0x64,
91 0x53, 0x48, 0xcc, 0x4b, 0x51, 0x28, 0xc9, 0x48, 0x55, 0x28, 0x4e, 0x4d,
92 0xce, 0x07, 0x32, 0x93, 0x72, 0xf2, 0x93, 0xb3, 0x15, 0x32, 0x8b, 0x15,
93 0x92, 0xf3, 0x73, 0x0b, 0x8a, 0x52, 0x8b, 0x8b, 0x53, 0x53, 0xf4, 0x00
94 };
95
96 const u8 uncompressed[] = "The first block is uncompressed and the second block is compressed.";
97
98 auto const decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
99 EXPECT(decompressed.value().bytes() == (ReadonlyBytes { uncompressed, sizeof(uncompressed) - 1 }));
100}
101
102TEST_CASE(deflate_decompress_zeroes)
103{
104 Array<u8, 20> const compressed {
105 0xed, 0xc1, 0x01, 0x0d, 0x00, 0x00, 0x00, 0xc2, 0xa0, 0xf7, 0x4f, 0x6d,
106 0x0f, 0x07, 0x14, 0x00, 0x00, 0x00, 0xf0, 0x6e
107 };
108
109 Array<u8, 4096> const uncompressed { 0 };
110
111 auto const decompressed = Compress::DeflateDecompressor::decompress_all(compressed);
112 EXPECT(uncompressed == decompressed.value().bytes());
113}
114
115TEST_CASE(deflate_round_trip_store)
116{
117 auto original = ByteBuffer::create_uninitialized(1024).release_value();
118 fill_with_random(original.data(), 1024);
119 auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::STORE);
120 EXPECT(!compressed.is_error());
121 auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
122 EXPECT(!uncompressed.is_error());
123 EXPECT(uncompressed.value() == original);
124}
125
126TEST_CASE(deflate_round_trip_compress)
127{
128 auto original = ByteBuffer::create_zeroed(2048).release_value();
129 fill_with_random(original.data(), 1024); // we pre-filled the second half with 0s to make sure we test back references as well
130 // Since the different levels just change how much time is spent looking for better matches, just use fast here to reduce test time
131 auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::FAST);
132 EXPECT(!compressed.is_error());
133 auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
134 EXPECT(!uncompressed.is_error());
135 EXPECT(uncompressed.value() == original);
136}
137
138TEST_CASE(deflate_round_trip_compress_large)
139{
140 auto size = Compress::DeflateCompressor::block_size * 2;
141 auto original = ByteBuffer::create_uninitialized(size).release_value(); // Compress a buffer larger than the maximum block size to test the sliding window mechanism
142 fill_with_random(original.data(), size);
143 // Since the different levels just change how much time is spent looking for better matches, just use fast here to reduce test time
144 auto compressed = Compress::DeflateCompressor::compress_all(original, Compress::DeflateCompressor::CompressionLevel::FAST);
145 EXPECT(!compressed.is_error());
146 auto uncompressed = Compress::DeflateDecompressor::decompress_all(compressed.value());
147 EXPECT(!uncompressed.is_error());
148 EXPECT(uncompressed.value() == original);
149}
150
151TEST_CASE(deflate_compress_literals)
152{
153 // This byte array is known to not produce any back references with our lz77 implementation even at the highest compression settings
154 Array<u8, 0x13> test { 0, 0, 0, 0, 0x72, 0, 0, 0xee, 0, 0, 0, 0x26, 0, 0, 0, 0x28, 0, 0, 0x72 };
155 auto compressed = Compress::DeflateCompressor::compress_all(test, Compress::DeflateCompressor::CompressionLevel::GOOD);
156 EXPECT(!compressed.is_error());
157}