liblzf/lzf.c

/*
 * Copyright (c) 2000-2002 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"

static void
usage (int ec)
{
  fprintf (stderr, "\n"
           "lzf, a very leightweight compression/decompression filter\n"
           "written by Marc Lehmann <pcg@goof.com> You can find more info at\n"
           "http://liblzv.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:	1.2
Committed:	Sun Nov 17 11:39:26 2002 UTC (21 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.1:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.2	* Copyright (c) 2000-2002 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			static void
41			usage (int ec)
42			{
43			fprintf (stderr, "\n"
44			"lzf, a very leightweight compression/decompression filter\n"
45			"written by Marc Lehmann <pcg@goof.com> You can find more info at\n"
46			"http://liblzv.plan9.de/\n"
47			"\n"
48			"USAGE: lzf -c [-b blocksize] \| -d\n"
49			" -c compress\n"
50			" -d decompress\n"
51			" -b specify the blocksize (default 64k-1)\n"
52			"\n"
53			);
54
55			exit (ec);
56			}
57
58			/*
59			* Anatomy: an lzf file consists of any number of blocks in the following format:
60			*
61			* "ZV\0" 2-byte-usize <uncompressed data>
62			* "ZV\1" 2-byte-csize 2-byte-usize <compressed data>
63			* "ZV\2" 4-byte-crc32-0xdebb20e3 (NYI)
64			*
65			*/
66
67			static void compress (unsigned int blocksize)
68			{
69			ssize_t us;
70			unsigned int cs;
71			u8 buff1[64*1024];
72			u8 buff2[64*1024];
73			u8 header[3+2+2];
74
75			header[0] = 'Z';
76			header[1] = 'V';
77
78			for(;;) {
79			us = fread (buff1, 1, blocksize, stdin);
80
81			if (us < blocksize)
82			{
83			if (us == 0)
84			break;
85			else if (!feof (stdin))
86			{
87			perror ("compress");
88			exit (1);
89			}
90			}
91
92			cs = lzf_compress (buff1, us, buff2, us - 4);
93
94			if (cs)
95			{
96			header[2] = 1;
97			header[3] = cs >> 8;
98			header[4] = cs & 0xff;
99			header[5] = us >> 8;
100			header[6] = us & 0xff;
101
102			fwrite (header, 3+2+2, 1, stdout);
103			fwrite (buff2, cs, 1, stdout);
104			}
105			else
106			{
107			header[2] = 0;
108			header[3] = us >> 8;
109			header[4] = us & 0xff;
110
111			fwrite (header, 3+2, 1, stdout);
112			fwrite (buff1, us, 1, stdout);
113			}
114			} while (!feof (stdin));
115			}
116
117			static void decompress (void)
118			{
119			ssize_t us;
120			unsigned int cs;
121			u8 buff1[64*1024];
122			u8 buff2[64*1024];
123			u8 header[3+2+2];
124
125			for(;;) {
126			if (fread (header, 3+2, 1, stdin) != 1)
127			{
128			if (feof (stdin))
129			break;
130			else
131			{
132			perror ("decompress");
133			exit (1);
134			}
135			}
136
137			if (header[0] != 'Z' \|\| header[1] != 'V')
138			{
139			fprintf (stderr, "decompress: invalid stream - no magic number found\n");
140			exit (1);
141			}
142
143			cs = (header[3] << 8) \| header[4];
144
145			if (header[2] == 1)
146			{
147			if (fread (header+3+2, 2, 1, stdin) != 1)
148			{
149			perror ("decompress");
150			exit (1);
151			}
152
153			us = (header[5] << 8) \| header[6];
154
155			if (fread (buff1, cs, 1, stdin) != 1)
156			{
157			perror ("decompress");
158			exit (1);
159			}
160
161			if (lzf_decompress (buff1, cs, buff2, us) != us)
162			{
163			fprintf (stderr, "decompress: invalid stream - data corrupted\n");
164			exit (1);
165			}
166
167			fwrite (buff2, us, 1, stdout);
168			}
169			else if (header[2] == 0)
170			{
171			if (fread (buff2, cs, 1, stdin) != 1)
172			{
173			perror ("decompress");
174			exit (1);
175			}
176
177			fwrite (buff2, cs, 1, stdout);
178			}
179			else
180			{
181			fprintf (stderr, "decompress: invalid stream - unknown block type\n");
182			exit (1);
183			}
184			}
185			}
186
187			int
188			main (int argc, char *argv[])
189			{
190			int c;
191			unsigned int blocksize = 64*1024-1;
192			enum { m_compress, m_decompress } mode = m_compress;
193
194			while ((c = getopt (argc, argv, "cdb:h")) != -1)
195			switch (c)
196			{
197			case 'c':
198			mode = m_compress;
199			break;
200
201			case 'd':
202			mode = m_decompress;
203			break;
204
205			case 'b':
206			blocksize = atol (optarg);
207			break;
208
209			case 'h':
210			usage (0);
211
212			case ':':
213			fprintf (stderr, "required argument missing, use -h\n");
214			exit (1);
215
216			case '?':
217			fprintf (stderr, "unknown option, use -h\n");
218			exit (1);
219
220			default:
221			usage (1);
222			}
223
224			if (mode == m_compress)
225			compress (blocksize);
226			else if (mode == m_decompress)
227			decompress ();
228			else
229			abort ();
230
231			return 0;
232			}