liblzf/lzf.c

/*
 * Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
 * 
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 *   3.  The name of the author may not be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

#include <unistd.h>
#include <getopt.h>

#include "lzf.h"

typedef unsigned char u8;

static void
usage (int ec)
{
  fprintf (stderr, "\n"
           "lzf, a very lightweight compression/decompression filter\n"
           "written by Marc Lehmann <pcg@goof.com> You can find more info at\n"
           "http://liblzf.plan9.de/\n"
           "\n"
           "USAGE: lzf -c [-b blocksize] | -d\n"
           "          -c  compress\n"
           "          -d  decompress\n"
           "          -b  specify the blocksize (default 64k-1)\n"
           "\n"
    );

  exit (ec);
}

/*
 * Anatomy: an lzf file consists of any number of blocks in the following format:
 *
 * "ZV\0" 2-byte-usize <uncompressed data>
 * "ZV\1" 2-byte-csize 2-byte-usize <compressed data>
 * "ZV\2" 4-byte-crc32-0xdebb20e3 (NYI)
 * 
 */

static void compress (unsigned int blocksize)
{
  ssize_t us;
  unsigned int cs;
  u8 buff1[64*1024];
  u8 buff2[64*1024];
  u8 header[3+2+2];

  header[0] = 'Z';
  header[1] = 'V';

  for(;;) {
    us = fread (buff1, 1, blocksize, stdin);

    if (us < blocksize)
      {
        if (us == 0)
          break;
        else if (!feof (stdin))
          {
            perror ("compress");
            exit (1);
          }
      }

    cs = lzf_compress (buff1, us, buff2, us - 4);

    if (cs)
      {
        header[2] = 1;
        header[3] = cs >> 8;
        header[4] = cs & 0xff;
        header[5] = us >> 8;
        header[6] = us & 0xff;

        fwrite (header, 3+2+2, 1, stdout);
        fwrite (buff2, cs, 1, stdout);
      }
    else
      {
        header[2] = 0;
        header[3] = us >> 8;
        header[4] = us & 0xff;

        fwrite (header, 3+2, 1, stdout);
        fwrite (buff1, us, 1, stdout);
      }
  } while (!feof (stdin));
}

static void decompress (void)
{
  ssize_t us;
  unsigned int cs;
  u8 buff1[64*1024];
  u8 buff2[64*1024];
  u8 header[3+2+2];

  for(;;) {
    if (fread (header, 3+2, 1, stdin) != 1)
      {
        if (feof (stdin))
          break;
        else
          {
            perror ("decompress");
            exit (1);
          }
      }

    if (header[0] != 'Z' || header[1] != 'V')
      {
        fprintf (stderr, "decompress: invalid stream - no magic number found\n");
        exit (1);
      }

    cs = (header[3] << 8) | header[4];

    if (header[2] == 1)
      {
        if (fread (header+3+2, 2, 1, stdin) != 1)
          {
            perror ("decompress");
            exit (1);
          }

        us = (header[5] << 8) | header[6];

        if (fread (buff1, cs, 1, stdin) != 1)
          {
            perror ("decompress");
            exit (1);
          }

        if (lzf_decompress (buff1, cs, buff2, us) != us)
          {
            fprintf (stderr, "decompress: invalid stream - data corrupted\n");
            exit (1);
          }

        fwrite (buff2, us, 1, stdout);
      }
    else if (header[2] == 0)
      {
        if (fread (buff2, cs, 1, stdin) != 1)
          {
            perror ("decompress");
            exit (1);
          }

        fwrite (buff2, cs, 1, stdout);
      }
    else
      {
        fprintf (stderr, "decompress: invalid stream - unknown block type\n");
        exit (1);
      }
  }
}

int
main (int argc, char *argv[])
{
  int c;
  unsigned int blocksize = 64*1024-1;
  enum { m_compress, m_decompress } mode = m_compress;

  while ((c = getopt (argc, argv, "cdb:h")) != -1)
    switch (c)
      {
      case 'c':
        mode = m_compress;
        break;

      case 'd':
        mode = m_decompress;
        break;

      case 'b':
        blocksize = atol (optarg);
        break;

      case 'h':
        usage (0);

      case ':':
        fprintf (stderr, "required argument missing, use -h\n");
        exit (1);

      case '?':
        fprintf (stderr, "unknown option, use -h\n");
        exit (1);

      default:
        usage (1);
      }

  if (mode == m_compress)
    compress (blocksize);
  else if (mode == m_decompress)
    decompress ();
  else
    abort ();

  return 0;
}
Revision:	1.3
Committed:	Tue Dec 23 04:52:00 2003 UTC (20 years, 9 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+5 -3 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	pcg	1.3	* Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
3	root	1.1	*
4			* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6			*
7			* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9			*
10			* 2. Redistributions in binary form must reproduce the above copyright
11			* notice, this list of conditions and the following disclaimer in the
12			* documentation and/or other materials provided with the distribution.
13			*
14			* 3. The name of the author may not be used to endorse or promote products
15			* derived from this software without specific prior written permission.
16			*
17			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27			*/
28
29			#include "config.h"
30
31			#include <stdio.h>
32			#include <stdlib.h>
33			#include <assert.h>
34
35			#include <unistd.h>
36			#include <getopt.h>
37
38			#include "lzf.h"
39
40	pcg	1.3	typedef unsigned char u8;
41
42	root	1.1	static void
43			usage (int ec)
44			{
45			fprintf (stderr, "\n"
46	pcg	1.3	"lzf, a very lightweight compression/decompression filter\n"
47	root	1.1	"written by Marc Lehmann <pcg@goof.com> You can find more info at\n"
48	pcg	1.3	"http://liblzf.plan9.de/\n"
49	root	1.1	"\n"
50			"USAGE: lzf -c [-b blocksize] \| -d\n"
51			" -c compress\n"
52			" -d decompress\n"
53			" -b specify the blocksize (default 64k-1)\n"
54			"\n"
55			);
56
57			exit (ec);
58			}
59
60			/*
61			* Anatomy: an lzf file consists of any number of blocks in the following format:
62			*
63			* "ZV\0" 2-byte-usize <uncompressed data>
64			* "ZV\1" 2-byte-csize 2-byte-usize <compressed data>
65			* "ZV\2" 4-byte-crc32-0xdebb20e3 (NYI)
66			*
67			*/
68
69			static void compress (unsigned int blocksize)
70			{
71			ssize_t us;
72			unsigned int cs;
73			u8 buff1[64*1024];
74			u8 buff2[64*1024];
75			u8 header[3+2+2];
76
77			header[0] = 'Z';
78			header[1] = 'V';
79
80			for(;;) {
81			us = fread (buff1, 1, blocksize, stdin);
82
83			if (us < blocksize)
84			{
85			if (us == 0)
86			break;
87			else if (!feof (stdin))
88			{
89			perror ("compress");
90			exit (1);
91			}
92			}
93
94			cs = lzf_compress (buff1, us, buff2, us - 4);
95
96			if (cs)
97			{
98			header[2] = 1;
99			header[3] = cs >> 8;
100			header[4] = cs & 0xff;
101			header[5] = us >> 8;
102			header[6] = us & 0xff;
103
104			fwrite (header, 3+2+2, 1, stdout);
105			fwrite (buff2, cs, 1, stdout);
106			}
107			else
108			{
109			header[2] = 0;
110			header[3] = us >> 8;
111			header[4] = us & 0xff;
112
113			fwrite (header, 3+2, 1, stdout);
114			fwrite (buff1, us, 1, stdout);
115			}
116			} while (!feof (stdin));
117			}
118
119			static void decompress (void)
120			{
121			ssize_t us;
122			unsigned int cs;
123			u8 buff1[64*1024];
124			u8 buff2[64*1024];
125			u8 header[3+2+2];
126
127			for(;;) {
128			if (fread (header, 3+2, 1, stdin) != 1)
129			{
130			if (feof (stdin))
131			break;
132			else
133			{
134			perror ("decompress");
135			exit (1);
136			}
137			}
138
139			if (header[0] != 'Z' \|\| header[1] != 'V')
140			{
141			fprintf (stderr, "decompress: invalid stream - no magic number found\n");
142			exit (1);
143			}
144
145			cs = (header[3] << 8) \| header[4];
146
147			if (header[2] == 1)
148			{
149			if (fread (header+3+2, 2, 1, stdin) != 1)
150			{
151			perror ("decompress");
152			exit (1);
153			}
154
155			us = (header[5] << 8) \| header[6];
156
157			if (fread (buff1, cs, 1, stdin) != 1)
158			{
159			perror ("decompress");
160			exit (1);
161			}
162
163			if (lzf_decompress (buff1, cs, buff2, us) != us)
164			{
165			fprintf (stderr, "decompress: invalid stream - data corrupted\n");
166			exit (1);
167			}
168
169			fwrite (buff2, us, 1, stdout);
170			}
171			else if (header[2] == 0)
172			{
173			if (fread (buff2, cs, 1, stdin) != 1)
174			{
175			perror ("decompress");
176			exit (1);
177			}
178
179			fwrite (buff2, cs, 1, stdout);
180			}
181			else
182			{
183			fprintf (stderr, "decompress: invalid stream - unknown block type\n");
184			exit (1);
185			}
186			}
187			}
188
189			int
190			main (int argc, char *argv[])
191			{
192			int c;
193			unsigned int blocksize = 64*1024-1;
194			enum { m_compress, m_decompress } mode = m_compress;
195
196			while ((c = getopt (argc, argv, "cdb:h")) != -1)
197			switch (c)
198			{
199			case 'c':
200			mode = m_compress;
201			break;
202
203			case 'd':
204			mode = m_decompress;
205			break;
206
207			case 'b':
208			blocksize = atol (optarg);
209			break;
210
211			case 'h':
212			usage (0);
213
214			case ':':
215			fprintf (stderr, "required argument missing, use -h\n");
216			exit (1);
217
218			case '?':
219			fprintf (stderr, "unknown option, use -h\n");
220			exit (1);
221
222			default:
223			usage (1);
224			}
225
226			if (mode == m_compress)
227			compress (blocksize);
228			else if (mode == m_decompress)
229			decompress ();
230			else
231			abort ();
232
233			return 0;
234			}