aboutsummaryrefslogtreecommitdiff
path: root/engines/tony/mpal/lzo.cpp
blob: 1bb54af1f07ab618491b008fba7685478b301472 (plain)
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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
/* minilzo.c -- mini subset of the LZO real-time data compression library

   This file is part of the LZO real-time data compression library.

   Copyright (C) 2011 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
   Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
   All Rights Reserved.

   The LZO library is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of
   the License, or (at your option) any later version.

   The LZO library 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with the LZO library; see the file COPYING.
   If not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

   Markus F.X.J. Oberhumer
   <markus@oberhumer.com>
   http://www.oberhumer.com/opensource/lzo/
 */

#include "lzo.h"
#include "common/textconsole.h"

namespace Tony {

namespace MPAL {

#define pd(a, b)       ((uint32) ((a) - (b)))
#define TEST_IP        (ip < ip_end)

#define M2_MAX_OFFSET 0x0800

/**
 * Decompresses an LZO compressed resource
 */
int lzo1x_decompress(const byte *in, uint32 in_len, byte *out, uint32 *out_len) {
	byte *op;
	const byte *ip;
	uint32 t = 0;
	const byte *m_pos;

	const byte * const ip_end = in + in_len;

	*out_len = 0;

	op = out;
	ip = in;

	if (*ip > 17) {
		t = *ip++ - 17;
		if (t < 4)
			goto match_next;
		assert(t > 0);
		do {
			*op++ = *ip++;
		} while (--t > 0);
		goto first_literal_run;
	}

	while (TEST_IP) {
		t = *ip++;
		if (t >= 16)
			goto match;
		if (t == 0) {
			while (*ip == 0) {
				t += 255;
				ip++;
			}
			t += 15 + *ip++;
		}
		assert(t > 0);

		*op++ = *ip++;
		*op++ = *ip++;
		*op++ = *ip++;
		do {
			*op++ = *ip++;
		} while (--t > 0);

first_literal_run:
		t = *ip++;
		if (t >= 16)
			goto match;

		m_pos = op - (1 + M2_MAX_OFFSET);
		m_pos -= t >> 2;
		m_pos -= *ip++ << 2;

		*op++ = *m_pos++;
		*op++ = *m_pos++;
		*op++ = *m_pos;

		goto match_done;

		do {
match:
			if (t >= 64) {
				m_pos = op - 1;
				m_pos -= (t >> 2) & 7;
				m_pos -= *ip++ << 3;
				t = (t >> 5) - 1;
				assert(t > 0);
				goto copy_match;
			} else if (t >= 32) {
				t &= 31;
				if (t == 0) {
					while (*ip == 0) {
						t += 255;
						ip++;
					}
					t += 31 + *ip++;
				}
				m_pos = op - 1;
				m_pos -= (ip[0] >> 2) + (ip[1] << 6);
				ip += 2;
			} else if (t >= 16) {
				m_pos = op;
				m_pos -= (t & 8) << 11;
				t &= 7;
				if (t == 0) {
					while (*ip == 0) {
						t += 255;
						ip++;
					}
					t += 7 + *ip++;
				}
				m_pos -= (ip[0] >> 2) + (ip[1] << 6);
				ip += 2;
				if (m_pos == op)
					goto eof_found;
				m_pos -= 0x4000;
			} else {
				m_pos = op - 1;
				m_pos -= t >> 2;
				m_pos -= *ip++ << 2;
				*op++ = *m_pos++;
				*op++ = *m_pos;
				goto match_done;
			}

			assert(t > 0);
			{
copy_match:
				*op++ = *m_pos++;
				*op++ = *m_pos++;
				do {
					*op++ = *m_pos++;
				} while (--t > 0);
			}

match_done:
			t = ip[-2] & 3;
			if (t == 0)
				break;

match_next:
			assert(t > 0);
			assert(t < 4);
			*op++ = *ip++;
			if (t > 1) {
				*op++ = *ip++;
				if (t > 2)
					*op++ = *ip++;
			}
			t = *ip++;
		} while (TEST_IP);
	}

eof_found:
	assert(t == 1);
	*out_len = pd(op, out);
	return (ip == ip_end ? LZO_E_OK :
	        (ip < ip_end  ? LZO_E_INPUT_NOT_CONSUMED : LZO_E_INPUT_OVERRUN));

}

} // end of namespace MPAL
} // end of namespace Tony