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
|
/* simple.c -- the annotated simple example program for the LZO library
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2017 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/
*/
/*************************************************************************
// This program shows the basic usage of the LZO library.
// We will compress a block of data and decompress again.
//
// See also LZO.FAQ
**************************************************************************/
/* We will be using the LZO1X-1 algorithm, so we have
* to include <lzo/lzo1x.h>
*/
#include <lzo/lzoconf.h>
#include <lzo/lzo1x.h>
/* portability layer */
static const char *progname = NULL;
#define WANT_LZO_MALLOC 1
#define WANT_XMALLOC 1
#include "examples/portab.h"
/* We want to compress the data block at 'in' with length 'IN_LEN' to
* the block at 'out'. Because the input block may be incompressible,
* we must provide a little more output space in case that compression
* is not possible.
*/
#ifndef IN_LEN
#define IN_LEN (128*1024L)
#endif
#define OUT_LEN (IN_LEN + IN_LEN / 16 + 64 + 3)
/*************************************************************************
//
**************************************************************************/
int __lzo_cdecl_main main(int argc, char *argv[])
{
int r;
lzo_bytep in;
lzo_bytep out;
lzo_voidp wrkmem;
lzo_uint in_len;
lzo_uint out_len;
lzo_uint new_len;
if (argc < 0 && argv == NULL) /* avoid warning about unused args */
return 0;
printf("\nLZO real-time data compression library (v%s, %s).\n",
lzo_version_string(), lzo_version_date());
printf("Copyright (C) 1996-2017 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n");
/*
* Step 1: initialize the LZO library
*/
if (lzo_init() != LZO_E_OK)
{
printf("internal error - lzo_init() failed !!!\n");
printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable '-DLZO_DEBUG' for diagnostics)\n");
return 4;
}
/*
* Step 2: allocate blocks and the work-memory
*/
in = (lzo_bytep) xmalloc(IN_LEN);
out = (lzo_bytep) xmalloc(OUT_LEN);
wrkmem = (lzo_voidp) xmalloc(LZO1X_1_MEM_COMPRESS);
if (in == NULL || out == NULL || wrkmem == NULL)
{
printf("out of memory\n");
return 3;
}
/*
* Step 3: prepare the input block that will get compressed.
* We just fill it with zeros in this example program,
* but you would use your real-world data here.
*/
in_len = IN_LEN;
lzo_memset(in,0,in_len);
/*
* Step 4: compress from 'in' to 'out' with LZO1X-1
*/
r = lzo1x_1_compress(in, in_len, out, &out_len, wrkmem);
if (r == LZO_E_OK)
printf("compressed %lu bytes into %lu bytes\n",
(unsigned long) in_len, (unsigned long) out_len);
else
{
/* this should NEVER happen */
printf("internal error - compression failed: %d\n", r);
return 2;
}
/* check for an incompressible block */
if (out_len >= in_len)
{
printf("This block contains incompressible data.\n");
return 0;
}
/*
* Step 5: decompress again, now going from 'out' to 'in'
*/
new_len = in_len;
r = lzo1x_decompress(out, out_len, in, &new_len, NULL);
if (r == LZO_E_OK && new_len == in_len)
printf("decompressed %lu bytes back into %lu bytes\n",
(unsigned long) out_len, (unsigned long) in_len);
else
{
/* this should NEVER happen */
printf("internal error - decompression failed: %d\n", r);
return 1;
}
lzo_free(wrkmem);
lzo_free(out);
lzo_free(in);
printf("Simple compression test passed.\n");
return 0;
}
/* vim:set ts=4 sw=4 et: */
|
