/* precomp.c -- example program: how to generate pre-compressed data
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2014 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 how to generate pre-compressed data.
//
// Please study LZO.FAQ and simple.c first.
//
// We will be trying both LZO1X-999 and LZO1Y-999 and choose
// the algorithm that achieves the best compression ratio.
**************************************************************************/
#include "lzo/lzoconf.h"
#include "lzo/lzo1x.h"
#include "lzo/lzo1y.h"
#define USE_LZO1X 1
#define USE_LZO1Y 1
#define PARANOID 1
/* portability layer */
static const char *progname = NULL;
#define WANT_LZO_MALLOC 1
#define WANT_LZO_FREAD 1
#define WANT_LZO_WILDARGV 1
#define WANT_XMALLOC 1
#include "examples/portab.h"
/*************************************************************************
//
**************************************************************************/
int __lzo_cdecl_main main(int argc, char *argv[])
{
int r;
lzo_bytep in;
lzo_uint in_len;
lzo_bytep out;
lzo_uint out_bufsize;
lzo_uint out_len = 0;
lzo_voidp wrkmem;
lzo_uint wrkmem_size;
lzo_uint best_len;
int best_compress = -1;
lzo_uint orig_len;
lzo_uint32_t uncompressed_checksum;
lzo_uint32_t compressed_checksum;
FILE *fp;
const char *in_name = NULL;
const char *out_name = NULL;
long l;
lzo_wildargv(&argc, &argv);
printf("\nLZO real-time data compression library (v%s, %s).\n",
lzo_version_string(), lzo_version_date());
printf("Copyright (C) 1996-2014 Markus Franz Xaver Johannes Oberhumer\nAll Rights Reserved.\n\n");
progname = argv[0];
if (argc < 2 || argc > 3)
{
printf("usage: %s file [output-file]\n", progname);
exit(1);
}
in_name = argv[1];
if (argc > 2) out_name = argv[2];
/*
* 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");
exit(1);
}
/*
* Step 2: allocate the work-memory
*/
wrkmem_size = 1;
#ifdef USE_LZO1X
wrkmem_size = (LZO1X_999_MEM_COMPRESS > wrkmem_size) ? LZO1X_999_MEM_COMPRESS : wrkmem_size;
#endif
#ifdef USE_LZO1Y
wrkmem_size = (LZO1Y_999_MEM_COMPRESS > wrkmem_size) ? LZO1Y_999_MEM_COMPRESS : wrkmem_size;
#endif
wrkmem = (lzo_voidp) xmalloc(wrkmem_size);
if (wrkmem == NULL)
{
printf("%s: out of memory\n", progname);
exit(1);
}
/*
* Step 3: open the input file
*/
fp = fopen(in_name,"rb");
if (fp == NULL)
{
printf("%s: cannot open file %s\n", progname, in_name);
exit(1);
}
fseek(fp, 0, SEEK_END);
l = ftell(fp);
fseek(fp, 0, SEEK_SET);
if (l <= 0)
{
printf("%s: %s: empty file\n", progname, in_name);
fclose(fp); fp = NULL;
exit(1);
}
in_len = (lzo_uint) l;
out_bufsize = in_len + in_len / 16 + 64 + 3;
best_len = in_len;
/*
* Step 4: allocate compression buffers and read the file
*/
in = (lzo_bytep) xmalloc(in_len);
out = (lzo_bytep) xmalloc(out_bufsize);
if (in == NULL || out == NULL)
{
printf("%s: out of memory\n", progname);
exit(1);
}
in_len = (lzo_uint) lzo_fread(fp, in, in_len);
printf("%s: loaded file %s: %ld bytes\n", progname, in_name, (long) in_len);
fclose(fp); fp = NULL;
/*
* Step 5: compute a checksum of the uncompressed data
*/
uncompressed_checksum = lzo_adler32(0,NULL,0);
uncompressed_checksum = lzo_adler32(uncompressed_checksum,in,in_len);
/*
* Step 6a: compress from 'in' to 'out' with LZO1X-999
*/
#ifdef USE_LZO1X
out_len = out_bufsize;
r = lzo1x_999_compress(in,in_len,out,&out_len,wrkmem);
if (r != LZO_E_OK)
{
/* this should NEVER happen */
printf("internal error - compression failed: %d\n", r);
exit(1);
}
printf("LZO1X-999: %8lu -> %8lu\n", (unsigned long) in_len, (unsigned long) out_len);
if (out_len < best_len)
{
best_len = out_len;
best_compress = 1; /* LZO1X-999 */
}
#endif /* USE_LZO1X */
/*
* Step 6b: compress from 'in' to 'out' with LZO1Y-999
*/
#ifdef USE_LZO1Y
out_len = out_bufsize;
r = lzo1y_999_compress(in,in_len,out,&out_len,wrkmem);
if (r != LZO_E_OK)
{
/* this should NEVER happen */
printf("internal error - compression failed: %d\n", r);
exit(1);
}
printf("LZO1Y-999: %8lu -> %8lu\n", (unsigned long) in_len, (unsigned long) out_len);
if (out_len < best_len)
{
best_len = out_len;
best_compress = 2; /* LZO1Y-999 */
}
#endif /* USE_LZO1Y */
/*
* Step 7: check if compressible
*/
if (best_len >= in_len)
{
printf("This file contains incompressible data.\n");
return 0;
}
/*
* Step 8: compress data again using the best compressor found
*/
out_len = out_bufsize;
if (best_compress == 1)
r = lzo1x_999_compress(in,in_len,out,&out_len,wrkmem);
else if (best_compress == 2)
r = lzo1y_999_compress(in,in_len,out,&out_len,wrkmem);
else
r = -100;
assert(r == LZO_E_OK);
assert(out_len == best_len);
/*
* Step 9: optimize compressed data (compressed data is in 'out' buffer)
*/
#if 1
/* Optimization does not require any data in the buffer that will
* hold the uncompressed data. To prove this, we clear the buffer.
*/
lzo_memset(in,0,in_len);
#endif
orig_len = in_len;
r = -100;
#ifdef USE_LZO1X
if (best_compress == 1)
r = lzo1x_optimize(out,out_len,in,&orig_len,NULL);
#endif
#ifdef USE_LZO1Y
if (best_compress == 2)
r = lzo1y_optimize(out,out_len,in,&orig_len,NULL);
#endif
if (r != LZO_E_OK || orig_len != in_len)
{
/* this should NEVER happen */
printf("internal error - optimization failed: %d\n", r);
exit(1);
}
/*
* Step 10: compute a checksum of the compressed data
*/
compressed_checksum = lzo_adler32(0,NULL,0);
compressed_checksum = lzo_adler32(compressed_checksum,out,out_len);
/*
* Step 11: write compressed data to a file
*/
printf("%s: %s: %ld -> %ld, checksum 0x%08lx 0x%08lx\n",
progname, in_name, (long) in_len, (long) out_len,
(long) uncompressed_checksum, (long) compressed_checksum);
if (out_name && out_name[0])
{
printf("%s: writing to file %s\n", progname, out_name);
fp = fopen(out_name,"wb");
if (fp == NULL)
{
printf("%s: cannot open output file %s\n", progname, out_name);
exit(1);
}
if (lzo_fwrite(fp, out, out_len) != out_len || fclose(fp) != 0)
{
printf("%s: write error !!\n", progname);
exit(1);
}
}
/*
* Step 12: verify decompression
*/
#ifdef PARANOID
lzo_memset(in,0,in_len); /* paranoia - clear output buffer */
orig_len = in_len;
r = -100;
#ifdef USE_LZO1X
if (best_compress == 1)
r = lzo1x_decompress_safe(out,out_len,in,&orig_len,NULL);
#endif
#ifdef USE_LZO1Y
if (best_compress == 2)
r = lzo1y_decompress_safe(out,out_len,in,&orig_len,NULL);
#endif
if (r != LZO_E_OK || orig_len != in_len)
{
/* this should NEVER happen */
printf("internal error - decompression failed: %d\n", r);
exit(1);
}
if (uncompressed_checksum != lzo_adler32(lzo_adler32(0,NULL,0),in,in_len))
{
/* this should NEVER happen */
printf("internal error - decompression data error\n");
exit(1);
}
/* Now you could also verify decompression under similar conditions as in
* your application, e.g. overlapping assembler decompression etc.
*/
#endif
lzo_free(in);
lzo_free(out);
lzo_free(wrkmem);
return 0;
}
/* vim:set ts=4 sw=4 et: */