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/* 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) 1996-2015 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) 1996-2015 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: */
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