1/* simple.c -- the annotated simple example program for the LZO library
2
3   This file is part of the LZO real-time data compression library.
4
5   Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
6   Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
7   Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
8   Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
9   Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
10   Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
11   Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
12   Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
13   Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
14   Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
15   Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
16   Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
17   Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
18   All Rights Reserved.
19
20   The LZO library is free software; you can redistribute it and/or
21   modify it under the terms of the GNU General Public License as
22   published by the Free Software Foundation; either version 2 of
23   the License, or (at your option) any later version.
24
25   The LZO library is distributed in the hope that it will be useful,
26   but WITHOUT ANY WARRANTY; without even the implied warranty of
27   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
28   GNU General Public License for more details.
29
30   You should have received a copy of the GNU General Public License
31   along with the LZO library; see the file COPYING.
32   If not, write to the Free Software Foundation, Inc.,
33   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
34
35   Markus F.X.J. Oberhumer
36   <markus@oberhumer.com>
37   http://www.oberhumer.com/opensource/lzo/
38 */
39
40
41/*************************************************************************
42// This program shows the basic usage of the LZO library.
43// We will compress a block of data and decompress again.
44//
45// See also LZO.FAQ
46**************************************************************************/
47
48/* We will be using the LZO1X-1 algorithm, so we have
49 * to include <lzo1x.h>
50 */
51
52#include "lzo/lzoconf.h"
53#include "lzo/lzo1x.h"
54
55/* portability layer */
56#define WANT_LZO_MALLOC 1
57#include "examples/portab.h"
58
59
60/* We want to compress the data block at `in' with length `IN_LEN' to
61 * the block at `out'. Because the input block may be incompressible,
62 * we must provide a little more output space in case that compression
63 * is not possible.
64 */
65
66#ifndef IN_LEN
67#define IN_LEN      (128*1024L)
68#endif
69#define OUT_LEN     (IN_LEN + IN_LEN / 16 + 64 + 3)
70
71
72/*************************************************************************
73//
74**************************************************************************/
75
76int __lzo_cdecl_main main(int argc, char *argv[])
77{
78    int r;
79    lzo_bytep in;
80    lzo_bytep out;
81    lzo_bytep wrkmem;
82    lzo_uint in_len;
83    lzo_uint out_len;
84    lzo_uint new_len;
85
86    if (argc < 0 && argv == NULL)   /* avoid warning about unused args */
87        return 0;
88
89    printf("\nLZO real-time data compression library (v%s, %s).\n",
90           lzo_version_string(), lzo_version_date());
91    printf("Copyright (C) 1996-2008 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n");
92
93/*
94 * Step 1: initialize the LZO library
95 */
96    if (lzo_init() != LZO_E_OK)
97    {
98        printf("internal error - lzo_init() failed !!!\n");
99        printf("(this usually indicates a compiler bug - try recompiling\nwithout optimizations, and enable `-DLZO_DEBUG' for diagnostics)\n");
100        return 4;
101    }
102
103/*
104 * Step 2: allocate blocks and the work-memory
105 */
106    in = (lzo_bytep) lzo_malloc(IN_LEN);
107    out = (lzo_bytep) lzo_malloc(OUT_LEN);
108    wrkmem = (lzo_bytep) lzo_malloc(LZO1X_1_MEM_COMPRESS);
109    if (in == NULL || out == NULL || wrkmem == NULL)
110    {
111        printf("out of memory\n");
112        return 3;
113    }
114
115/*
116 * Step 3: prepare the input block that will get compressed.
117 *         We just fill it with zeros in this example program,
118 *         but you would use your real-world data here.
119 */
120    in_len = IN_LEN;
121    lzo_memset(in,0,in_len);
122
123/*
124 * Step 4: compress from `in' to `out' with LZO1X-1
125 */
126    r = lzo1x_1_compress(in,in_len,out,&out_len,wrkmem);
127    if (r == LZO_E_OK)
128        printf("compressed %lu bytes into %lu bytes\n",
129            (unsigned long) in_len, (unsigned long) out_len);
130    else
131    {
132        /* this should NEVER happen */
133        printf("internal error - compression failed: %d\n", r);
134        return 2;
135    }
136    /* check for an incompressible block */
137    if (out_len >= in_len)
138    {
139        printf("This block contains incompressible data.\n");
140        return 0;
141    }
142
143/*
144 * Step 5: decompress again, now going from `out' to `in'
145 */
146    new_len = in_len;
147    r = lzo1x_decompress(out,out_len,in,&new_len,NULL);
148    if (r == LZO_E_OK && new_len == in_len)
149        printf("decompressed %lu bytes back into %lu bytes\n",
150            (unsigned long) out_len, (unsigned long) in_len);
151    else
152    {
153        /* this should NEVER happen */
154        printf("internal error - decompression failed: %d\n", r);
155        return 1;
156    }
157
158    lzo_free(wrkmem);
159    lzo_free(out);
160    lzo_free(in);
161    printf("Simple compression test passed.\n");
162    return 0;
163}
164
165/*
166vi:ts=4:et
167*/
168
169