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, 4 months ago) by pcg
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+5 -3 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright (c) 2000-2003 Marc Alexander Lehmann <pcg@goof.com>
3	*
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	typedef unsigned char u8;
41
42	static void
43	usage (int ec)
44	{
45	fprintf (stderr, "\n"
46	"lzf, a very lightweight compression/decompression filter\n"
47	"written by Marc Lehmann <pcg@goof.com> You can find more info at\n"
48	"http://liblzf.plan9.de/\n"
49	"\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	}