blob: c31706af3720fb8e9c93250b22fce1465ae9ab6e [file] [log] [blame]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001/* vi: set sw=4 ts=4: */
Erik Andersen61677fe2000-04-13 01:18:56 +00002/*
3 * Gzip implementation for busybox
Eric Andersencc8ed391999-10-05 16:24:54 +00004 *
Erik Andersen61677fe2000-04-13 01:18:56 +00005 * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly.
6 *
7 * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com>
8 * "this is a stripped down version of gzip I put into busybox, it does
9 * only standard in to standard out with -9 compression. It also requires
10 * the zcat module for some important functions."
11 *
Eric Andersenc7bda1c2004-03-15 08:29:22 +000012 * Adjusted further by Erik Andersen <andersen@codepoet.org> to support
13 * files as well as stdin/stdout, and to generally behave itself wrt
Erik Andersen61677fe2000-04-13 01:18:56 +000014 * command line handling.
15 *
Bernhard Reutner-Fischer20f40002006-01-30 17:17:14 +000016 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
Eric Andersencc8ed391999-10-05 16:24:54 +000017 */
Eric Andersencc8ed391999-10-05 16:24:54 +000018
Erik Andersen61677fe2000-04-13 01:18:56 +000019/* These defines are very important for BusyBox. Without these,
Eric Andersenc7bda1c2004-03-15 08:29:22 +000020 * huge chunks of ram are pre-allocated making the BusyBox bss
Erik Andersen61677fe2000-04-13 01:18:56 +000021 * size Freaking Huge(tm), which is a bad thing.*/
22#define SMALL_MEM
23#define DYN_ALLOC
24
Eric Andersencbe31da2001-02-20 06:14:08 +000025#include <stdlib.h>
Eric Andersencc8ed391999-10-05 16:24:54 +000026#include <stdio.h>
Erik Andersen61677fe2000-04-13 01:18:56 +000027#include <string.h>
Eric Andersened3ef502001-01-27 08:24:39 +000028#include <unistd.h>
Glenn L McGrathf58efb52001-03-28 05:35:16 +000029#include <errno.h>
Eric Andersen3073dfb2001-07-02 17:57:32 +000030#include <sys/types.h>
31#include <signal.h>
32#include <utime.h>
33#include <ctype.h>
34#include <sys/types.h>
35#include <unistd.h>
36#include <dirent.h>
37#include <fcntl.h>
38#include <time.h>
Eric Andersencbe31da2001-02-20 06:14:08 +000039#include "busybox.h"
Eric Andersencbe31da2001-02-20 06:14:08 +000040
Erik Andersene49d5ec2000-02-08 19:58:47 +000041typedef unsigned char uch;
Eric Andersencc8ed391999-10-05 16:24:54 +000042typedef unsigned short ush;
Erik Andersene49d5ec2000-02-08 19:58:47 +000043typedef unsigned long ulg;
Eric Andersencc8ed391999-10-05 16:24:54 +000044
45/* Return codes from gzip */
46#define OK 0
47#define ERROR 1
48#define WARNING 2
49
50/* Compression methods (see algorithm.doc) */
Eric Andersen3073dfb2001-07-02 17:57:32 +000051/* Only STORED and DEFLATED are supported by this BusyBox module */
Eric Andersencc8ed391999-10-05 16:24:54 +000052#define STORED 0
Eric Andersencc8ed391999-10-05 16:24:54 +000053/* methods 4 to 7 reserved */
54#define DEFLATED 8
Eric Andersencc8ed391999-10-05 16:24:54 +000055
56/* To save memory for 16 bit systems, some arrays are overlaid between
57 * the various modules:
58 * deflate: prev+head window d_buf l_buf outbuf
59 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
Eric Andersencc8ed391999-10-05 16:24:54 +000060 * For compression, input is done in window[]. For decompression, output
61 * is done in window except for unlzw.
62 */
63
64#ifndef INBUFSIZ
65# ifdef SMALL_MEM
Erik Andersene49d5ec2000-02-08 19:58:47 +000066# define INBUFSIZ 0x2000 /* input buffer size */
Eric Andersencc8ed391999-10-05 16:24:54 +000067# else
Erik Andersene49d5ec2000-02-08 19:58:47 +000068# define INBUFSIZ 0x8000 /* input buffer size */
Eric Andersencc8ed391999-10-05 16:24:54 +000069# endif
70#endif
Glenn L McGrathd827e8b2002-08-22 13:21:26 +000071#define INBUF_EXTRA 64 /* required by unlzw() */
Eric Andersencc8ed391999-10-05 16:24:54 +000072
73#ifndef OUTBUFSIZ
74# ifdef SMALL_MEM
Erik Andersene49d5ec2000-02-08 19:58:47 +000075# define OUTBUFSIZ 8192 /* output buffer size */
Eric Andersencc8ed391999-10-05 16:24:54 +000076# else
Erik Andersene49d5ec2000-02-08 19:58:47 +000077# define OUTBUFSIZ 16384 /* output buffer size */
Eric Andersencc8ed391999-10-05 16:24:54 +000078# endif
79#endif
Glenn L McGrathd827e8b2002-08-22 13:21:26 +000080#define OUTBUF_EXTRA 2048 /* required by unlzw() */
Eric Andersencc8ed391999-10-05 16:24:54 +000081
82#ifndef DIST_BUFSIZE
83# ifdef SMALL_MEM
Erik Andersene49d5ec2000-02-08 19:58:47 +000084# define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
Eric Andersencc8ed391999-10-05 16:24:54 +000085# else
Erik Andersene49d5ec2000-02-08 19:58:47 +000086# define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
Eric Andersencc8ed391999-10-05 16:24:54 +000087# endif
88#endif
89
90#ifdef DYN_ALLOC
Eric Andersen3073dfb2001-07-02 17:57:32 +000091# define DECLARE(type, array, size) static type * array
Eric Andersencc8ed391999-10-05 16:24:54 +000092# define ALLOC(type, array, size) { \
Eric Andersen39eb0402001-08-22 04:15:47 +000093 array = (type*)xcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
Eric Andersencc8ed391999-10-05 16:24:54 +000094 }
Aaron Lehmanna170e1c2002-11-28 11:27:31 +000095# define FREE(array) {free(array), array=NULL;}
Eric Andersencc8ed391999-10-05 16:24:54 +000096#else
Eric Andersen3073dfb2001-07-02 17:57:32 +000097# define DECLARE(type, array, size) static type array[size]
Eric Andersencc8ed391999-10-05 16:24:54 +000098# define ALLOC(type, array, size)
99# define FREE(array)
100#endif
101
Eric Andersencc8ed391999-10-05 16:24:54 +0000102#define tab_suffix window
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000103#define tab_prefix prev /* hash link (see deflate.c) */
104#define head (prev+WSIZE) /* hash head (see deflate.c) */
Eric Andersencc8ed391999-10-05 16:24:54 +0000105
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000106static long bytes_in; /* number of input bytes */
Eric Andersencc8ed391999-10-05 16:24:54 +0000107
108#define isize bytes_in
109/* for compatibility with old zip sources (to be cleaned) */
110
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000111typedef int file_t; /* Do not use stdio */
Erik Andersene49d5ec2000-02-08 19:58:47 +0000112
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000113#define NO_FILE (-1) /* in memory compression */
Eric Andersencc8ed391999-10-05 16:24:54 +0000114
115
Erik Andersene49d5ec2000-02-08 19:58:47 +0000116#define PACK_MAGIC "\037\036" /* Magic header for packed files */
117#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
118#define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
119#define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */
120#define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
Eric Andersencc8ed391999-10-05 16:24:54 +0000121
122/* gzip flag byte */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000123#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
124#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
125#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
126#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
127#define COMMENT 0x10 /* bit 4 set: file comment present */
128#define RESERVED 0xC0 /* bit 6,7: reserved */
Eric Andersencc8ed391999-10-05 16:24:54 +0000129
130/* internal file attribute */
131#define UNKNOWN 0xffff
132#define BINARY 0
133#define ASCII 1
134
135#ifndef WSIZE
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000136# define WSIZE 0x8000 /* window size--must be a power of two, and */
Erik Andersene49d5ec2000-02-08 19:58:47 +0000137#endif /* at least 32K for zip's deflate method */
Eric Andersencc8ed391999-10-05 16:24:54 +0000138
139#define MIN_MATCH 3
140#define MAX_MATCH 258
141/* The minimum and maximum match lengths */
142
143#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
144/* Minimum amount of lookahead, except at the end of the input file.
145 * See deflate.c for comments about the MIN_MATCH+1.
146 */
147
148#define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
149/* In order to simplify the code, particularly on 16 bit machines, match
150 * distances are limited to MAX_DIST instead of WSIZE.
151 */
152
Eric Andersen3073dfb2001-07-02 17:57:32 +0000153/* put_byte is used for the compressed output */
Eric Andersencc8ed391999-10-05 16:24:54 +0000154#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
155 flush_outbuf();}
Eric Andersencc8ed391999-10-05 16:24:54 +0000156
Eric Andersencc8ed391999-10-05 16:24:54 +0000157
158/* Output a 32 bit value to the bit stream, lsb first */
Eric Andersen39eb0402001-08-22 04:15:47 +0000159#if 0
Eric Andersencc8ed391999-10-05 16:24:54 +0000160#define put_long(n) { \
161 put_short((n) & 0xffff); \
162 put_short(((ulg)(n)) >> 16); \
163}
Eric Andersen39eb0402001-08-22 04:15:47 +0000164#endif
Eric Andersencc8ed391999-10-05 16:24:54 +0000165
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000166#define seekable() 0 /* force sequential output */
167#define translate_eol 0 /* no option -a yet */
Eric Andersencc8ed391999-10-05 16:24:54 +0000168
Eric Andersencc8ed391999-10-05 16:24:54 +0000169/* Diagnostic functions */
170#ifdef DEBUG
Manuel Novoa III cad53642003-03-19 09:13:01 +0000171# define Assert(cond,msg) {if(!(cond)) bb_error_msg(msg);}
Eric Andersencc8ed391999-10-05 16:24:54 +0000172# define Trace(x) fprintf x
173# define Tracev(x) {if (verbose) fprintf x ;}
174# define Tracevv(x) {if (verbose>1) fprintf x ;}
175# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
176# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
177#else
178# define Assert(cond,msg)
179# define Trace(x)
180# define Tracev(x)
181# define Tracevv(x)
182# define Tracec(c,x)
183# define Tracecv(c,x)
184#endif
185
186#define WARN(msg) {if (!quiet) fprintf msg ; \
187 if (exit_code == OK) exit_code = WARNING;}
188
Eric Andersen3073dfb2001-07-02 17:57:32 +0000189#ifndef MAX_PATH_LEN
190# define MAX_PATH_LEN 1024 /* max pathname length */
191#endif
Eric Andersencc8ed391999-10-05 16:24:54 +0000192
Eric Andersencc8ed391999-10-05 16:24:54 +0000193
Eric Andersen3073dfb2001-07-02 17:57:32 +0000194 /* from zip.c: */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000195static int zip(int in, int out);
196static int file_read(char *buf, unsigned size);
Eric Andersencc8ed391999-10-05 16:24:54 +0000197
Eric Andersen3073dfb2001-07-02 17:57:32 +0000198 /* from deflate.c */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000199static void lm_init(ush * flags);
200static ulg deflate(void);
Eric Andersencc8ed391999-10-05 16:24:54 +0000201
Eric Andersen3073dfb2001-07-02 17:57:32 +0000202 /* from trees.c */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000203static void ct_init(ush * attr, int *methodp);
204static int ct_tally(int dist, int lc);
205static ulg flush_block(char *buf, ulg stored_len, int eof);
Eric Andersencc8ed391999-10-05 16:24:54 +0000206
Eric Andersen3073dfb2001-07-02 17:57:32 +0000207 /* from bits.c */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000208static void bi_init(file_t zipfile);
209static void send_bits(int value, int length);
210static unsigned bi_reverse(unsigned value, int length);
211static void bi_windup(void);
212static void copy_block(char *buf, unsigned len, int header);
Eric Andersen3073dfb2001-07-02 17:57:32 +0000213static int (*read_buf) (char *buf, unsigned size);
Eric Andersencc8ed391999-10-05 16:24:54 +0000214
Eric Andersen3073dfb2001-07-02 17:57:32 +0000215 /* from util.c: */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000216static void flush_outbuf(void);
Erik Andersene49d5ec2000-02-08 19:58:47 +0000217
Eric Andersencc8ed391999-10-05 16:24:54 +0000218/* lzw.h -- define the lzw functions.
219 * Copyright (C) 1992-1993 Jean-loup Gailly.
220 * This is free software; you can redistribute it and/or modify it under the
221 * terms of the GNU General Public License, see the file COPYING.
222 */
223
Eric Andersencc8ed391999-10-05 16:24:54 +0000224#ifndef BITS
225# define BITS 16
226#endif
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000227#define INIT_BITS 9 /* Initial number of bits per code */
Eric Andersencc8ed391999-10-05 16:24:54 +0000228
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000229#define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
Eric Andersencc8ed391999-10-05 16:24:54 +0000230/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
231 * It's a pity that old uncompress does not check bit 0x20. That makes
232 * extension of the format actually undesirable because old compress
233 * would just crash on the new format instead of giving a meaningful
234 * error message. It does check the number of bits, but it's more
235 * helpful to say "unsupported format, get a new version" than
236 * "can only handle 16 bits".
237 */
238
Eric Andersencc8ed391999-10-05 16:24:54 +0000239/* tailor.h -- target dependent definitions
240 * Copyright (C) 1992-1993 Jean-loup Gailly.
241 * This is free software; you can redistribute it and/or modify it under the
242 * terms of the GNU General Public License, see the file COPYING.
243 */
244
245/* The target dependent definitions should be defined here only.
246 * The target dependent functions should be defined in tailor.c.
247 */
248
Eric Andersencc8ed391999-10-05 16:24:54 +0000249
Eric Andersencc8ed391999-10-05 16:24:54 +0000250 /* Common defaults */
251
252#ifndef OS_CODE
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000253# define OS_CODE 0x03 /* assume Unix */
Eric Andersencc8ed391999-10-05 16:24:54 +0000254#endif
255
256#ifndef PATH_SEP
257# define PATH_SEP '/'
258#endif
259
Eric Andersencc8ed391999-10-05 16:24:54 +0000260#ifndef OPTIONS_VAR
261# define OPTIONS_VAR "GZIP"
262#endif
263
264#ifndef Z_SUFFIX
265# define Z_SUFFIX ".gz"
266#endif
267
268#ifdef MAX_EXT_CHARS
269# define MAX_SUFFIX MAX_EXT_CHARS
270#else
271# define MAX_SUFFIX 30
272#endif
273
Eric Andersen3073dfb2001-07-02 17:57:32 +0000274 /* global buffers */
Eric Andersencc8ed391999-10-05 16:24:54 +0000275
Eric Andersen3073dfb2001-07-02 17:57:32 +0000276DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
277DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
278DECLARE(ush, d_buf, DIST_BUFSIZE);
279DECLARE(uch, window, 2L * WSIZE);
280DECLARE(ush, tab_prefix, 1L << BITS);
Eric Andersencc8ed391999-10-05 16:24:54 +0000281
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000282static int foreground; /* set if program run in foreground */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000283static int method = DEFLATED; /* compression method */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000284static int exit_code = OK; /* program exit code */
285static int part_nb; /* number of parts in .gz file */
286static long time_stamp; /* original time stamp (modification time) */
287static long ifile_size; /* input file size, -1 for devices (debug only) */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000288static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000289static int z_len; /* strlen(z_suffix) */
Eric Andersencc8ed391999-10-05 16:24:54 +0000290
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000291static int ifd; /* input file descriptor */
292static int ofd; /* output file descriptor */
293static unsigned insize; /* valid bytes in inbuf */
294static unsigned outcnt; /* bytes in output buffer */
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000295
Rob Landleyc57ec372006-04-10 17:07:15 +0000296static uint32_t *crc_32_tab;
Aaron Lehmannb9df4702001-12-06 03:22:43 +0000297
298/* Output a 16 bit value, lsb first */
299static void put_short(ush w)
300{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000301 if (outcnt < OUTBUFSIZ - 2) {
302 outbuf[outcnt++] = (uch) ((w) & 0xff);
303 outbuf[outcnt++] = (uch) ((ush) (w) >> 8);
304 } else {
305 put_byte((uch) ((w) & 0xff));
306 put_byte((uch) ((ush) (w) >> 8));
307 }
Aaron Lehmannb9df4702001-12-06 03:22:43 +0000308}
309
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000310/* ========================================================================
311 * Signal and error handler.
312 */
Bernhard Reutner-Fischer20f40002006-01-30 17:17:14 +0000313static void abort_gzip(int ATTRIBUTE_UNUSED ignored)
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000314{
315 exit(ERROR);
316}
317
318/* ===========================================================================
319 * Clear input and output buffers
320 */
321static void clear_bufs(void)
322{
323 outcnt = 0;
Eric Andersen3073dfb2001-07-02 17:57:32 +0000324 insize = 0;
325 bytes_in = 0L;
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000326}
327
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000328/* ===========================================================================
329 * Does the same as write(), but also handles partial pipe writes and checks
330 * for error return.
331 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000332static void write_buf(int fd, void *buf, unsigned cnt)
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000333{
334 unsigned n;
335
336 while ((n = write(fd, buf, cnt)) != cnt) {
Rob Landleyec4f3d92004-12-17 05:23:36 +0000337 if (n == (unsigned) (-1)) bb_error_msg_and_die("can't write");
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000338 cnt -= n;
339 buf = (void *) ((char *) buf + n);
340 }
341}
342
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000343/* ===========================================================================
344 * Run a set of bytes through the crc shift register. If s is a NULL
345 * pointer, then initialize the crc shift register contents instead.
346 * Return the current crc in either case.
347 */
Rob Landleyc57ec372006-04-10 17:07:15 +0000348static uint32_t updcrc(uch * s, unsigned n)
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000349{
Rob Landleyc57ec372006-04-10 17:07:15 +0000350 static uint32_t crc = ~0; /* shift register contents */
351 uint32_t c; /* temporary variable */
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000352
353 if (s == NULL) {
Rob Landleyc57ec372006-04-10 17:07:15 +0000354 c = ~0;
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000355 } else {
356 c = crc;
357 if (n)
358 do {
359 c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8);
360 } while (--n);
361 }
362 crc = c;
Rob Landleyc57ec372006-04-10 17:07:15 +0000363 return ~c;
Glenn L McGrathf58efb52001-03-28 05:35:16 +0000364}
365
Eric Andersencc8ed391999-10-05 16:24:54 +0000366/* bits.c -- output variable-length bit strings
367 * Copyright (C) 1992-1993 Jean-loup Gailly
368 * This is free software; you can redistribute it and/or modify it under the
369 * terms of the GNU General Public License, see the file COPYING.
370 */
371
372
373/*
374 * PURPOSE
375 *
376 * Output variable-length bit strings. Compression can be done
377 * to a file or to memory. (The latter is not supported in this version.)
378 *
379 * DISCUSSION
380 *
381 * The PKZIP "deflate" file format interprets compressed file data
382 * as a sequence of bits. Multi-bit strings in the file may cross
383 * byte boundaries without restriction.
384 *
385 * The first bit of each byte is the low-order bit.
386 *
387 * The routines in this file allow a variable-length bit value to
388 * be output right-to-left (useful for literal values). For
389 * left-to-right output (useful for code strings from the tree routines),
390 * the bits must have been reversed first with bi_reverse().
391 *
392 * For in-memory compression, the compressed bit stream goes directly
393 * into the requested output buffer. The input data is read in blocks
394 * by the mem_read() function. The buffer is limited to 64K on 16 bit
395 * machines.
396 *
397 * INTERFACE
398 *
399 * void bi_init (FILE *zipfile)
400 * Initialize the bit string routines.
401 *
402 * void send_bits (int value, int length)
403 * Write out a bit string, taking the source bits right to
404 * left.
405 *
406 * int bi_reverse (int value, int length)
407 * Reverse the bits of a bit string, taking the source bits left to
408 * right and emitting them right to left.
409 *
410 * void bi_windup (void)
411 * Write out any remaining bits in an incomplete byte.
412 *
413 * void copy_block(char *buf, unsigned len, int header)
414 * Copy a stored block to the zip file, storing first the length and
415 * its one's complement if requested.
416 *
417 */
418
Eric Andersencc8ed391999-10-05 16:24:54 +0000419/* ===========================================================================
420 * Local data used by the "bit string" routines.
421 */
422
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000423static file_t zfile; /* output gzip file */
Eric Andersencc8ed391999-10-05 16:24:54 +0000424
Eric Andersen3073dfb2001-07-02 17:57:32 +0000425static unsigned short bi_buf;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000426
Eric Andersencc8ed391999-10-05 16:24:54 +0000427/* Output buffer. bits are inserted starting at the bottom (least significant
428 * bits).
429 */
430
431#define Buf_size (8 * 2*sizeof(char))
432/* Number of bits used within bi_buf. (bi_buf might be implemented on
433 * more than 16 bits on some systems.)
434 */
435
Eric Andersen3073dfb2001-07-02 17:57:32 +0000436static int bi_valid;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000437
Eric Andersencc8ed391999-10-05 16:24:54 +0000438/* Current input function. Set to mem_read for in-memory compression */
439
440#ifdef DEBUG
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000441ulg bits_sent; /* bit length of the compressed data */
Eric Andersencc8ed391999-10-05 16:24:54 +0000442#endif
443
444/* ===========================================================================
445 * Initialize the bit string routines.
446 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000447static void bi_init(file_t zipfile)
Eric Andersencc8ed391999-10-05 16:24:54 +0000448{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000449 zfile = zipfile;
450 bi_buf = 0;
451 bi_valid = 0;
Eric Andersencc8ed391999-10-05 16:24:54 +0000452#ifdef DEBUG
Erik Andersene49d5ec2000-02-08 19:58:47 +0000453 bits_sent = 0L;
Eric Andersencc8ed391999-10-05 16:24:54 +0000454#endif
455
Erik Andersene49d5ec2000-02-08 19:58:47 +0000456 /* Set the defaults for file compression. They are set by memcompress
457 * for in-memory compression.
458 */
459 if (zfile != NO_FILE) {
460 read_buf = file_read;
461 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000462}
463
464/* ===========================================================================
465 * Send a value on a given number of bits.
466 * IN assertion: length <= 16 and value fits in length bits.
467 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000468static void send_bits(int value, int length)
Eric Andersencc8ed391999-10-05 16:24:54 +0000469{
470#ifdef DEBUG
Erik Andersene49d5ec2000-02-08 19:58:47 +0000471 Tracev((stderr, " l %2d v %4x ", length, value));
472 Assert(length > 0 && length <= 15, "invalid length");
473 bits_sent += (ulg) length;
Eric Andersencc8ed391999-10-05 16:24:54 +0000474#endif
Erik Andersene49d5ec2000-02-08 19:58:47 +0000475 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
476 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
477 * unused bits in value.
478 */
479 if (bi_valid > (int) Buf_size - length) {
480 bi_buf |= (value << bi_valid);
481 put_short(bi_buf);
482 bi_buf = (ush) value >> (Buf_size - bi_valid);
483 bi_valid += length - Buf_size;
484 } else {
485 bi_buf |= value << bi_valid;
486 bi_valid += length;
487 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000488}
489
490/* ===========================================================================
491 * Reverse the first len bits of a code, using straightforward code (a faster
492 * method would use a table)
493 * IN assertion: 1 <= len <= 15
494 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000495static unsigned bi_reverse(unsigned code, int len)
Eric Andersencc8ed391999-10-05 16:24:54 +0000496{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000497 register unsigned res = 0;
498
499 do {
500 res |= code & 1;
501 code >>= 1, res <<= 1;
502 } while (--len > 0);
503 return res >> 1;
Eric Andersencc8ed391999-10-05 16:24:54 +0000504}
505
506/* ===========================================================================
507 * Write out any remaining bits in an incomplete byte.
508 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +0000509static void bi_windup(void)
Eric Andersencc8ed391999-10-05 16:24:54 +0000510{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000511 if (bi_valid > 8) {
512 put_short(bi_buf);
513 } else if (bi_valid > 0) {
514 put_byte(bi_buf);
515 }
516 bi_buf = 0;
517 bi_valid = 0;
Eric Andersencc8ed391999-10-05 16:24:54 +0000518#ifdef DEBUG
Erik Andersene49d5ec2000-02-08 19:58:47 +0000519 bits_sent = (bits_sent + 7) & ~7;
Eric Andersencc8ed391999-10-05 16:24:54 +0000520#endif
521}
522
523/* ===========================================================================
524 * Copy a stored block to the zip file, storing first the length and its
525 * one's complement if requested.
526 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000527static void copy_block(char *buf, unsigned len, int header)
Eric Andersencc8ed391999-10-05 16:24:54 +0000528{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000529 bi_windup(); /* align on byte boundary */
Eric Andersencc8ed391999-10-05 16:24:54 +0000530
Erik Andersene49d5ec2000-02-08 19:58:47 +0000531 if (header) {
532 put_short((ush) len);
533 put_short((ush) ~ len);
Eric Andersencc8ed391999-10-05 16:24:54 +0000534#ifdef DEBUG
Erik Andersene49d5ec2000-02-08 19:58:47 +0000535 bits_sent += 2 * 16;
Eric Andersencc8ed391999-10-05 16:24:54 +0000536#endif
Erik Andersene49d5ec2000-02-08 19:58:47 +0000537 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000538#ifdef DEBUG
Erik Andersene49d5ec2000-02-08 19:58:47 +0000539 bits_sent += (ulg) len << 3;
Eric Andersencc8ed391999-10-05 16:24:54 +0000540#endif
Erik Andersene49d5ec2000-02-08 19:58:47 +0000541 while (len--) {
Erik Andersene49d5ec2000-02-08 19:58:47 +0000542 put_byte(*buf++);
543 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000544}
Erik Andersene49d5ec2000-02-08 19:58:47 +0000545
Eric Andersencc8ed391999-10-05 16:24:54 +0000546/* deflate.c -- compress data using the deflation algorithm
547 * Copyright (C) 1992-1993 Jean-loup Gailly
548 * This is free software; you can redistribute it and/or modify it under the
549 * terms of the GNU General Public License, see the file COPYING.
550 */
551
552/*
553 * PURPOSE
554 *
555 * Identify new text as repetitions of old text within a fixed-
556 * length sliding window trailing behind the new text.
557 *
558 * DISCUSSION
559 *
560 * The "deflation" process depends on being able to identify portions
561 * of the input text which are identical to earlier input (within a
562 * sliding window trailing behind the input currently being processed).
563 *
564 * The most straightforward technique turns out to be the fastest for
565 * most input files: try all possible matches and select the longest.
566 * The key feature of this algorithm is that insertions into the string
567 * dictionary are very simple and thus fast, and deletions are avoided
568 * completely. Insertions are performed at each input character, whereas
569 * string matches are performed only when the previous match ends. So it
570 * is preferable to spend more time in matches to allow very fast string
571 * insertions and avoid deletions. The matching algorithm for small
572 * strings is inspired from that of Rabin & Karp. A brute force approach
573 * is used to find longer strings when a small match has been found.
574 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
575 * (by Leonid Broukhis).
576 * A previous version of this file used a more sophisticated algorithm
577 * (by Fiala and Greene) which is guaranteed to run in linear amortized
578 * time, but has a larger average cost, uses more memory and is patented.
579 * However the F&G algorithm may be faster for some highly redundant
580 * files if the parameter max_chain_length (described below) is too large.
581 *
Eric Andersenaff114c2004-04-14 17:51:38 +0000582 * ACKNOWLEDGMENTS
Eric Andersencc8ed391999-10-05 16:24:54 +0000583 *
584 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
585 * I found it in 'freeze' written by Leonid Broukhis.
586 * Thanks to many info-zippers for bug reports and testing.
587 *
588 * REFERENCES
589 *
590 * APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
591 *
592 * A description of the Rabin and Karp algorithm is given in the book
593 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
594 *
595 * Fiala,E.R., and Greene,D.H.
596 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
597 *
598 * INTERFACE
599 *
600 * void lm_init (int pack_level, ush *flags)
601 * Initialize the "longest match" routines for a new file
602 *
603 * ulg deflate (void)
604 * Processes a new input file and return its compressed length. Sets
605 * the compressed length, crc, deflate flags and internal file
606 * attributes.
607 */
608
Eric Andersencc8ed391999-10-05 16:24:54 +0000609
Eric Andersencc8ed391999-10-05 16:24:54 +0000610/* ===========================================================================
611 * Configuration parameters
612 */
613
614/* Compile with MEDIUM_MEM to reduce the memory requirements or
615 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
616 * entire input file can be held in memory (not possible on 16 bit systems).
617 * Warning: defining these symbols affects HASH_BITS (see below) and thus
618 * affects the compression ratio. The compressed output
619 * is still correct, and might even be smaller in some cases.
620 */
621
622#ifdef SMALL_MEM
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000623# define HASH_BITS 13 /* Number of bits used to hash strings */
Eric Andersencc8ed391999-10-05 16:24:54 +0000624#endif
625#ifdef MEDIUM_MEM
626# define HASH_BITS 14
627#endif
628#ifndef HASH_BITS
629# define HASH_BITS 15
630 /* For portability to 16 bit machines, do not use values above 15. */
631#endif
632
633/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
634 * window with tab_suffix. Check that we can do this:
635 */
636#if (WSIZE<<1) > (1<<BITS)
Eric Andersen3073dfb2001-07-02 17:57:32 +0000637# error cannot overlay window with tab_suffix and prev with tab_prefix0
Eric Andersencc8ed391999-10-05 16:24:54 +0000638#endif
639#if HASH_BITS > BITS-1
Eric Andersen3073dfb2001-07-02 17:57:32 +0000640# error cannot overlay head with tab_prefix1
Eric Andersencc8ed391999-10-05 16:24:54 +0000641#endif
Eric Andersencc8ed391999-10-05 16:24:54 +0000642#define HASH_SIZE (unsigned)(1<<HASH_BITS)
643#define HASH_MASK (HASH_SIZE-1)
644#define WMASK (WSIZE-1)
645/* HASH_SIZE and WSIZE must be powers of two */
Eric Andersencc8ed391999-10-05 16:24:54 +0000646#define NIL 0
647/* Tail of hash chains */
Eric Andersencc8ed391999-10-05 16:24:54 +0000648#define FAST 4
649#define SLOW 2
650/* speed options for the general purpose bit flag */
Eric Andersencc8ed391999-10-05 16:24:54 +0000651#ifndef TOO_FAR
652# define TOO_FAR 4096
653#endif
654/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
Eric Andersencc8ed391999-10-05 16:24:54 +0000655/* ===========================================================================
656 * Local data used by the "longest match" routines.
657 */
Eric Andersencc8ed391999-10-05 16:24:54 +0000658typedef ush Pos;
659typedef unsigned IPos;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000660
Eric Andersencc8ed391999-10-05 16:24:54 +0000661/* A Pos is an index in the character window. We use short instead of int to
662 * save space in the various tables. IPos is used only for parameter passing.
663 */
664
665/* DECLARE(uch, window, 2L*WSIZE); */
666/* Sliding window. Input bytes are read into the second half of the window,
667 * and move to the first half later to keep a dictionary of at least WSIZE
668 * bytes. With this organization, matches are limited to a distance of
669 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
670 * performed with a length multiple of the block size. Also, it limits
671 * the window size to 64K, which is quite useful on MSDOS.
672 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
673 * be less efficient).
674 */
675
676/* DECLARE(Pos, prev, WSIZE); */
677/* Link to older string with same hash index. To limit the size of this
678 * array to 64K, this link is maintained only for the last 32K strings.
679 * An index in this array is thus a window index modulo 32K.
680 */
681
682/* DECLARE(Pos, head, 1<<HASH_BITS); */
683/* Heads of the hash chains or NIL. */
684
Eric Andersen3073dfb2001-07-02 17:57:32 +0000685static const ulg window_size = (ulg) 2 * WSIZE;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000686
Eric Andersencc8ed391999-10-05 16:24:54 +0000687/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
688 * input file length plus MIN_LOOKAHEAD.
689 */
690
Eric Andersen3073dfb2001-07-02 17:57:32 +0000691static long block_start;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000692
Eric Andersencc8ed391999-10-05 16:24:54 +0000693/* window position at the beginning of the current output block. Gets
694 * negative when the window is moved backwards.
695 */
696
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000697static unsigned ins_h; /* hash index of string to be inserted */
Eric Andersencc8ed391999-10-05 16:24:54 +0000698
699#define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
700/* Number of bits by which ins_h and del_h must be shifted at each
701 * input step. It must be such that after MIN_MATCH steps, the oldest
702 * byte no longer takes part in the hash key, that is:
703 * H_SHIFT * MIN_MATCH >= HASH_BITS
704 */
705
Eric Andersen3073dfb2001-07-02 17:57:32 +0000706static unsigned int prev_length;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000707
Eric Andersencc8ed391999-10-05 16:24:54 +0000708/* Length of the best match at previous step. Matches not greater than this
709 * are discarded. This is used in the lazy match evaluation.
710 */
711
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000712static unsigned strstart; /* start of string to insert */
713static unsigned match_start; /* start of matching string */
714static int eofile; /* flag set at end of input file */
715static unsigned lookahead; /* number of valid bytes ahead in window */
Eric Andersencc8ed391999-10-05 16:24:54 +0000716
Rob Landleybc68cd12006-03-10 19:22:06 +0000717enum {
718 max_chain_length = 4096,
Erik Andersene49d5ec2000-02-08 19:58:47 +0000719
Eric Andersencc8ed391999-10-05 16:24:54 +0000720/* To speed up deflation, hash chains are never searched beyond this length.
721 * A higher limit improves compression ratio but degrades the speed.
722 */
723
Rob Landleybc68cd12006-03-10 19:22:06 +0000724 max_lazy_match = 258,
Erik Andersene49d5ec2000-02-08 19:58:47 +0000725
Eric Andersencc8ed391999-10-05 16:24:54 +0000726/* Attempt to find a better match only when the current match is strictly
727 * smaller than this value. This mechanism is used only for compression
728 * levels >= 4.
729 */
Rob Landleybc68cd12006-03-10 19:22:06 +0000730 max_insert_length = max_lazy_match,
Eric Andersencc8ed391999-10-05 16:24:54 +0000731/* Insert new strings in the hash table only if the match length
732 * is not greater than this length. This saves time but degrades compression.
733 * max_insert_length is used only for compression levels <= 3.
734 */
735
Rob Landleybc68cd12006-03-10 19:22:06 +0000736 good_match = 32,
Erik Andersene49d5ec2000-02-08 19:58:47 +0000737
Eric Andersencc8ed391999-10-05 16:24:54 +0000738/* Use a faster search when the previous match is longer than this */
739
740
741/* Values for max_lazy_match, good_match and max_chain_length, depending on
742 * the desired pack level (0..9). The values given below have been tuned to
743 * exclude worst case performance for pathological files. Better values may be
744 * found for specific files.
745 */
746
Rob Landleybc68cd12006-03-10 19:22:06 +0000747 nice_match = 258 /* Stop searching when current match exceeds this */
Eric Andersencc8ed391999-10-05 16:24:54 +0000748
749/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
750 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
751 * meaning.
752 */
Rob Landleybc68cd12006-03-10 19:22:06 +0000753};
Eric Andersencc8ed391999-10-05 16:24:54 +0000754
755#define EQUAL 0
756/* result of memcmp for equal strings */
757
758/* ===========================================================================
759 * Prototypes for local functions.
760 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000761static void fill_window(void);
Eric Andersencc8ed391999-10-05 16:24:54 +0000762
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000763static int longest_match(IPos cur_match);
Eric Andersencc8ed391999-10-05 16:24:54 +0000764
765#ifdef DEBUG
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000766static void check_match(IPos start, IPos match, int length);
Eric Andersencc8ed391999-10-05 16:24:54 +0000767#endif
768
769/* ===========================================================================
770 * Update a hash value with the given input byte
771 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
772 * input characters, so that a running hash key can be computed from the
773 * previous key instead of complete recalculation each time.
774 */
775#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
776
777/* ===========================================================================
778 * Insert string s in the dictionary and set match_head to the previous head
779 * of the hash chain (the most recent string with same hash key). Return
780 * the previous length of the hash chain.
781 * IN assertion: all calls to to INSERT_STRING are made with consecutive
782 * input characters and the first MIN_MATCH bytes of s are valid
783 * (except for the last MIN_MATCH-1 bytes of the input file).
784 */
785#define INSERT_STRING(s, match_head) \
786 (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
787 prev[(s) & WMASK] = match_head = head[ins_h], \
788 head[ins_h] = (s))
789
790/* ===========================================================================
791 * Initialize the "longest match" routines for a new file
792 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000793static void lm_init(ush * flags)
Eric Andersencc8ed391999-10-05 16:24:54 +0000794{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000795 register unsigned j;
Eric Andersencc8ed391999-10-05 16:24:54 +0000796
Erik Andersene49d5ec2000-02-08 19:58:47 +0000797 /* Initialize the hash table. */
Rob Landleyec4f3d92004-12-17 05:23:36 +0000798 memset(head, 0, HASH_SIZE * sizeof(*head));
Erik Andersene49d5ec2000-02-08 19:58:47 +0000799 /* prev will be initialized on the fly */
Eric Andersencc8ed391999-10-05 16:24:54 +0000800
Erik Andersene49d5ec2000-02-08 19:58:47 +0000801 *flags |= SLOW;
802 /* ??? reduce max_chain_length for binary files */
Eric Andersencc8ed391999-10-05 16:24:54 +0000803
Erik Andersene49d5ec2000-02-08 19:58:47 +0000804 strstart = 0;
805 block_start = 0L;
Eric Andersencc8ed391999-10-05 16:24:54 +0000806
Erik Andersene49d5ec2000-02-08 19:58:47 +0000807 lookahead = read_buf((char *) window,
808 sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
Eric Andersencc8ed391999-10-05 16:24:54 +0000809
Erik Andersene49d5ec2000-02-08 19:58:47 +0000810 if (lookahead == 0 || lookahead == (unsigned) EOF) {
811 eofile = 1, lookahead = 0;
812 return;
813 }
814 eofile = 0;
815 /* Make sure that we always have enough lookahead. This is important
816 * if input comes from a device such as a tty.
817 */
818 while (lookahead < MIN_LOOKAHEAD && !eofile)
819 fill_window();
Eric Andersencc8ed391999-10-05 16:24:54 +0000820
Erik Andersene49d5ec2000-02-08 19:58:47 +0000821 ins_h = 0;
822 for (j = 0; j < MIN_MATCH - 1; j++)
823 UPDATE_HASH(ins_h, window[j]);
824 /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
825 * not important since only literal bytes will be emitted.
826 */
Eric Andersencc8ed391999-10-05 16:24:54 +0000827}
828
829/* ===========================================================================
830 * Set match_start to the longest match starting at the given string and
831 * return its length. Matches shorter or equal to prev_length are discarded,
832 * in which case the result is equal to prev_length and match_start is
833 * garbage.
834 * IN assertions: cur_match is the head of the hash chain for the current
835 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
836 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000837
Eric Andersencc8ed391999-10-05 16:24:54 +0000838/* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
839 * match.s. The code is functionally equivalent, so you can use the C version
840 * if desired.
841 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000842static int longest_match(IPos cur_match)
Eric Andersencc8ed391999-10-05 16:24:54 +0000843{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000844 unsigned chain_length = max_chain_length; /* max hash chain length */
845 register uch *scan = window + strstart; /* current string */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000846 register uch *match; /* matched string */
847 register int len; /* length of current match */
Erik Andersene49d5ec2000-02-08 19:58:47 +0000848 int best_len = prev_length; /* best match length so far */
849 IPos limit =
Erik Andersene49d5ec2000-02-08 19:58:47 +0000850 strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL;
851 /* Stop when cur_match becomes <= limit. To simplify the code,
852 * we prevent matches with the string of window index 0.
853 */
Eric Andersencc8ed391999-10-05 16:24:54 +0000854
855/* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
856 * It is easy to get rid of this optimization if necessary.
857 */
858#if HASH_BITS < 8 || MAX_MATCH != 258
Eric Andersen3073dfb2001-07-02 17:57:32 +0000859# error Code too clever
Eric Andersencc8ed391999-10-05 16:24:54 +0000860#endif
Erik Andersene49d5ec2000-02-08 19:58:47 +0000861 register uch *strend = window + strstart + MAX_MATCH;
862 register uch scan_end1 = scan[best_len - 1];
863 register uch scan_end = scan[best_len];
Eric Andersencc8ed391999-10-05 16:24:54 +0000864
Erik Andersene49d5ec2000-02-08 19:58:47 +0000865 /* Do not waste too much time if we already have a good match: */
866 if (prev_length >= good_match) {
867 chain_length >>= 2;
868 }
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000869 Assert(strstart <= window_size - MIN_LOOKAHEAD, "insufficient lookahead");
Eric Andersencc8ed391999-10-05 16:24:54 +0000870
Erik Andersene49d5ec2000-02-08 19:58:47 +0000871 do {
872 Assert(cur_match < strstart, "no future");
873 match = window + cur_match;
Eric Andersencc8ed391999-10-05 16:24:54 +0000874
Erik Andersene49d5ec2000-02-08 19:58:47 +0000875 /* Skip to next match if the match length cannot increase
876 * or if the match length is less than 2:
877 */
Erik Andersene49d5ec2000-02-08 19:58:47 +0000878 if (match[best_len] != scan_end ||
879 match[best_len - 1] != scan_end1 ||
880 *match != *scan || *++match != scan[1])
881 continue;
Eric Andersencc8ed391999-10-05 16:24:54 +0000882
Erik Andersene49d5ec2000-02-08 19:58:47 +0000883 /* The check at best_len-1 can be removed because it will be made
884 * again later. (This heuristic is not always a win.)
885 * It is not necessary to compare scan[2] and match[2] since they
886 * are always equal when the other bytes match, given that
887 * the hash keys are equal and that HASH_BITS >= 8.
888 */
889 scan += 2, match++;
Eric Andersencc8ed391999-10-05 16:24:54 +0000890
Erik Andersene49d5ec2000-02-08 19:58:47 +0000891 /* We check for insufficient lookahead only every 8th comparison;
892 * the 256th check will be made at strstart+258.
893 */
894 do {
895 } while (*++scan == *++match && *++scan == *++match &&
896 *++scan == *++match && *++scan == *++match &&
897 *++scan == *++match && *++scan == *++match &&
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000898 *++scan == *++match && *++scan == *++match && scan < strend);
Eric Andersencc8ed391999-10-05 16:24:54 +0000899
Erik Andersene49d5ec2000-02-08 19:58:47 +0000900 len = MAX_MATCH - (int) (strend - scan);
901 scan = strend - MAX_MATCH;
Eric Andersencc8ed391999-10-05 16:24:54 +0000902
Erik Andersene49d5ec2000-02-08 19:58:47 +0000903 if (len > best_len) {
904 match_start = cur_match;
905 best_len = len;
906 if (len >= nice_match)
907 break;
Erik Andersene49d5ec2000-02-08 19:58:47 +0000908 scan_end1 = scan[best_len - 1];
909 scan_end = scan[best_len];
Erik Andersene49d5ec2000-02-08 19:58:47 +0000910 }
911 } while ((cur_match = prev[cur_match & WMASK]) > limit
912 && --chain_length != 0);
Eric Andersencc8ed391999-10-05 16:24:54 +0000913
Erik Andersene49d5ec2000-02-08 19:58:47 +0000914 return best_len;
Eric Andersencc8ed391999-10-05 16:24:54 +0000915}
Eric Andersencc8ed391999-10-05 16:24:54 +0000916
917#ifdef DEBUG
918/* ===========================================================================
919 * Check that the match at match_start is indeed a match.
920 */
Eric Andersen3073dfb2001-07-02 17:57:32 +0000921static void check_match(IPos start, IPos match, int length)
Eric Andersencc8ed391999-10-05 16:24:54 +0000922{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000923 /* check that the match is indeed a match */
924 if (memcmp((char *) window + match,
925 (char *) window + start, length) != EQUAL) {
Manuel Novoa III cad53642003-03-19 09:13:01 +0000926 bb_error_msg(" start %d, match %d, length %d", start, match, length);
927 bb_error_msg("invalid match");
Erik Andersene49d5ec2000-02-08 19:58:47 +0000928 }
929 if (verbose > 1) {
Manuel Novoa III cad53642003-03-19 09:13:01 +0000930 bb_error_msg("\\[%d,%d]", start - match, length);
Erik Andersene49d5ec2000-02-08 19:58:47 +0000931 do {
932 putc(window[start++], stderr);
933 } while (--length != 0);
934 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000935}
936#else
937# define check_match(start, match, length)
938#endif
939
940/* ===========================================================================
941 * Fill the window when the lookahead becomes insufficient.
942 * Updates strstart and lookahead, and sets eofile if end of input file.
943 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
944 * OUT assertions: at least one byte has been read, or eofile is set;
945 * file reads are performed for at least two bytes (required for the
946 * translate_eol option).
947 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +0000948static void fill_window(void)
Eric Andersencc8ed391999-10-05 16:24:54 +0000949{
Erik Andersene49d5ec2000-02-08 19:58:47 +0000950 register unsigned n, m;
951 unsigned more =
Erik Andersene49d5ec2000-02-08 19:58:47 +0000952 (unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
953 /* Amount of free space at the end of the window. */
Eric Andersencc8ed391999-10-05 16:24:54 +0000954
Erik Andersene49d5ec2000-02-08 19:58:47 +0000955 /* If the window is almost full and there is insufficient lookahead,
956 * move the upper half to the lower one to make room in the upper half.
957 */
958 if (more == (unsigned) EOF) {
959 /* Very unlikely, but possible on 16 bit machine if strstart == 0
960 * and lookahead == 1 (input done one byte at time)
961 */
962 more--;
963 } else if (strstart >= WSIZE + MAX_DIST) {
964 /* By the IN assertion, the window is not empty so we can't confuse
965 * more == 0 with more == 64K on a 16 bit machine.
966 */
967 Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM");
Eric Andersencc8ed391999-10-05 16:24:54 +0000968
Erik Andersene49d5ec2000-02-08 19:58:47 +0000969 memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE);
970 match_start -= WSIZE;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +0000971 strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
Eric Andersencc8ed391999-10-05 16:24:54 +0000972
Erik Andersene49d5ec2000-02-08 19:58:47 +0000973 block_start -= (long) WSIZE;
974
975 for (n = 0; n < HASH_SIZE; n++) {
976 m = head[n];
977 head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
978 }
979 for (n = 0; n < WSIZE; n++) {
980 m = prev[n];
981 prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
982 /* If n is not on any hash chain, prev[n] is garbage but
983 * its value will never be used.
984 */
985 }
986 more += WSIZE;
987 }
988 /* At this point, more >= 2 */
989 if (!eofile) {
990 n = read_buf((char *) window + strstart + lookahead, more);
991 if (n == 0 || n == (unsigned) EOF) {
992 eofile = 1;
993 } else {
994 lookahead += n;
995 }
996 }
Eric Andersencc8ed391999-10-05 16:24:54 +0000997}
998
999/* ===========================================================================
1000 * Flush the current block, with given end-of-file flag.
1001 * IN assertion: strstart is set to the end of the current match.
1002 */
1003#define FLUSH_BLOCK(eof) \
1004 flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
Tim Rikerc1ef7bd2006-01-25 00:08:53 +00001005 (char*)NULL, (long)strstart - block_start, (eof))
Eric Andersencc8ed391999-10-05 16:24:54 +00001006
1007/* ===========================================================================
1008 * Same as above, but achieves better compression. We use a lazy
1009 * evaluation for matches: a match is finally adopted only if there is
1010 * no better match at the next window position.
1011 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +00001012static ulg deflate(void)
Eric Andersencc8ed391999-10-05 16:24:54 +00001013{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001014 IPos hash_head; /* head of hash chain */
1015 IPos prev_match; /* previous match */
1016 int flush; /* set if current block must be flushed */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001017 int match_available = 0; /* set if previous match exists */
1018 register unsigned match_length = MIN_MATCH - 1; /* length of best match */
1019
Erik Andersene49d5ec2000-02-08 19:58:47 +00001020 /* Process the input block. */
1021 while (lookahead != 0) {
1022 /* Insert the string window[strstart .. strstart+2] in the
1023 * dictionary, and set hash_head to the head of the hash chain:
1024 */
1025 INSERT_STRING(strstart, hash_head);
Eric Andersencc8ed391999-10-05 16:24:54 +00001026
Erik Andersene49d5ec2000-02-08 19:58:47 +00001027 /* Find the longest match, discarding those <= prev_length.
1028 */
1029 prev_length = match_length, prev_match = match_start;
1030 match_length = MIN_MATCH - 1;
Eric Andersencc8ed391999-10-05 16:24:54 +00001031
Erik Andersene49d5ec2000-02-08 19:58:47 +00001032 if (hash_head != NIL && prev_length < max_lazy_match &&
1033 strstart - hash_head <= MAX_DIST) {
1034 /* To simplify the code, we prevent matches with the string
1035 * of window index 0 (in particular we have to avoid a match
1036 * of the string with itself at the start of the input file).
1037 */
1038 match_length = longest_match(hash_head);
1039 /* longest_match() sets match_start */
1040 if (match_length > lookahead)
1041 match_length = lookahead;
Eric Andersencc8ed391999-10-05 16:24:54 +00001042
Erik Andersene49d5ec2000-02-08 19:58:47 +00001043 /* Ignore a length 3 match if it is too distant: */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001044 if (match_length == MIN_MATCH && strstart - match_start > TOO_FAR) {
Erik Andersene49d5ec2000-02-08 19:58:47 +00001045 /* If prev_match is also MIN_MATCH, match_start is garbage
1046 * but we will ignore the current match anyway.
1047 */
1048 match_length--;
1049 }
1050 }
1051 /* If there was a match at the previous step and the current
1052 * match is not better, output the previous match:
1053 */
1054 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
Eric Andersencc8ed391999-10-05 16:24:54 +00001055
Erik Andersene49d5ec2000-02-08 19:58:47 +00001056 check_match(strstart - 1, prev_match, prev_length);
Eric Andersencc8ed391999-10-05 16:24:54 +00001057
Erik Andersene49d5ec2000-02-08 19:58:47 +00001058 flush =
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001059 ct_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
Eric Andersencc8ed391999-10-05 16:24:54 +00001060
Erik Andersene49d5ec2000-02-08 19:58:47 +00001061 /* Insert in hash table all strings up to the end of the match.
1062 * strstart-1 and strstart are already inserted.
1063 */
1064 lookahead -= prev_length - 1;
1065 prev_length -= 2;
1066 do {
1067 strstart++;
1068 INSERT_STRING(strstart, hash_head);
1069 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1070 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1071 * these bytes are garbage, but it does not matter since the
1072 * next lookahead bytes will always be emitted as literals.
1073 */
1074 } while (--prev_length != 0);
1075 match_available = 0;
1076 match_length = MIN_MATCH - 1;
1077 strstart++;
1078 if (flush)
1079 FLUSH_BLOCK(0), block_start = strstart;
Eric Andersencc8ed391999-10-05 16:24:54 +00001080
Erik Andersene49d5ec2000-02-08 19:58:47 +00001081 } else if (match_available) {
1082 /* If there was no match at the previous position, output a
1083 * single literal. If there was a match but the current match
1084 * is longer, truncate the previous match to a single literal.
1085 */
1086 Tracevv((stderr, "%c", window[strstart - 1]));
1087 if (ct_tally(0, window[strstart - 1])) {
1088 FLUSH_BLOCK(0), block_start = strstart;
1089 }
1090 strstart++;
1091 lookahead--;
1092 } else {
1093 /* There is no previous match to compare with, wait for
1094 * the next step to decide.
1095 */
1096 match_available = 1;
1097 strstart++;
1098 lookahead--;
1099 }
1100 Assert(strstart <= isize && lookahead <= isize, "a bit too far");
Eric Andersencc8ed391999-10-05 16:24:54 +00001101
Erik Andersene49d5ec2000-02-08 19:58:47 +00001102 /* Make sure that we always have enough lookahead, except
1103 * at the end of the input file. We need MAX_MATCH bytes
1104 * for the next match, plus MIN_MATCH bytes to insert the
1105 * string following the next match.
1106 */
1107 while (lookahead < MIN_LOOKAHEAD && !eofile)
1108 fill_window();
1109 }
1110 if (match_available)
1111 ct_tally(0, window[strstart - 1]);
Eric Andersencc8ed391999-10-05 16:24:54 +00001112
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001113 return FLUSH_BLOCK(1); /* eof */
Eric Andersencc8ed391999-10-05 16:24:54 +00001114}
Erik Andersene49d5ec2000-02-08 19:58:47 +00001115
Eric Andersencc8ed391999-10-05 16:24:54 +00001116/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1117 * Copyright (C) 1992-1993 Jean-loup Gailly
1118 * The unzip code was written and put in the public domain by Mark Adler.
1119 * Portions of the lzw code are derived from the public domain 'compress'
1120 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1121 * Ken Turkowski, Dave Mack and Peter Jannesen.
1122 *
1123 * See the license_msg below and the file COPYING for the software license.
1124 * See the file algorithm.doc for the compression algorithms and file formats.
1125 */
1126
1127/* Compress files with zip algorithm and 'compress' interface.
1128 * See usage() and help() functions below for all options.
1129 * Outputs:
1130 * file.gz: compressed file with same mode, owner, and utimes
1131 * or stdout with -c option or if stdin used as input.
1132 * If the output file name had to be truncated, the original name is kept
1133 * in the compressed file.
Eric Andersencc8ed391999-10-05 16:24:54 +00001134 */
1135
Eric Andersencc8ed391999-10-05 16:24:54 +00001136 /* configuration */
1137
Erik Andersene49d5ec2000-02-08 19:58:47 +00001138typedef struct dirent dir_type;
1139
Eric Andersencc8ed391999-10-05 16:24:54 +00001140/* ======================================================================== */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001141int gzip_main(int argc, char **argv)
Eric Andersencc8ed391999-10-05 16:24:54 +00001142{
Erik Andersene49d5ec2000-02-08 19:58:47 +00001143 int result;
1144 int inFileNum;
1145 int outFileNum;
1146 struct stat statBuf;
1147 char *delFileName;
1148 int tostdout = 0;
Eric Andersenea824fb2000-07-21 22:17:39 +00001149 int force = 0;
Matt Kraai53265542001-04-18 16:05:34 +00001150 int opt;
Eric Andersen96bcfd31999-11-12 01:30:18 +00001151
Glenn L McGrath5bcfc9b2001-05-07 12:01:58 +00001152 while ((opt = getopt(argc, argv, "cf123456789dq")) != -1) {
Matt Kraai53265542001-04-18 16:05:34 +00001153 switch (opt) {
1154 case 'c':
Erik Andersene49d5ec2000-02-08 19:58:47 +00001155 tostdout = 1;
Matt Kraai53265542001-04-18 16:05:34 +00001156 break;
1157 case 'f':
1158 force = 1;
1159 break;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001160 /* Ignore 1-9 (compression level) options */
1161 case '1':
1162 case '2':
1163 case '3':
1164 case '4':
1165 case '5':
1166 case '6':
1167 case '7':
1168 case '8':
1169 case '9':
Matt Kraai53265542001-04-18 16:05:34 +00001170 break;
Glenn L McGrath5bcfc9b2001-05-07 12:01:58 +00001171 case 'q':
1172 break;
Eric Andersenbdfd0d72001-10-24 05:00:29 +00001173#ifdef CONFIG_GUNZIP
Matt Kraai53265542001-04-18 16:05:34 +00001174 case 'd':
1175 optind = 1;
1176 return gunzip_main(argc, argv);
Glenn L McGrath528ef502001-04-11 03:45:37 +00001177#endif
Matt Kraai53265542001-04-18 16:05:34 +00001178 default:
Manuel Novoa III cad53642003-03-19 09:13:01 +00001179 bb_show_usage();
Erik Andersene49d5ec2000-02-08 19:58:47 +00001180 }
1181 }
1182
1183 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1184 if (foreground) {
Rob Landleyec4f3d92004-12-17 05:23:36 +00001185 (void) signal(SIGINT, abort_gzip);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001186 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001187#ifdef SIGTERM
Erik Andersene49d5ec2000-02-08 19:58:47 +00001188 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
Rob Landleyec4f3d92004-12-17 05:23:36 +00001189 (void) signal(SIGTERM, abort_gzip);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001190 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001191#endif
1192#ifdef SIGHUP
Erik Andersene49d5ec2000-02-08 19:58:47 +00001193 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
Rob Landleyec4f3d92004-12-17 05:23:36 +00001194 (void) signal(SIGHUP, abort_gzip);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001195 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001196#endif
1197
Erik Andersene49d5ec2000-02-08 19:58:47 +00001198 strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
1199 z_len = strlen(z_suffix);
Eric Andersencc8ed391999-10-05 16:24:54 +00001200
Erik Andersene49d5ec2000-02-08 19:58:47 +00001201 /* Allocate all global buffers (for DYN_ALLOC option) */
1202 ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1203 ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1204 ALLOC(ush, d_buf, DIST_BUFSIZE);
1205 ALLOC(uch, window, 2L * WSIZE);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001206 ALLOC(ush, tab_prefix, 1L << BITS);
Eric Andersencc8ed391999-10-05 16:24:54 +00001207
Rob Landleyc57ec372006-04-10 17:07:15 +00001208 /* Initialise the CRC32 table */
1209 crc_32_tab = bb_crc32_filltable(0);
1210
Matt Kraai9bd49d62002-02-05 22:31:48 +00001211 clear_bufs();
1212 part_nb = 0;
Eric Andersen96bcfd31999-11-12 01:30:18 +00001213
Matt Kraai9bd49d62002-02-05 22:31:48 +00001214 if (optind == argc) {
1215 time_stamp = 0;
1216 ifile_size = -1L;
1217 zip(STDIN_FILENO, STDOUT_FILENO);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001218 } else {
Matt Kraai9bd49d62002-02-05 22:31:48 +00001219 int i;
Eric Andersen96bcfd31999-11-12 01:30:18 +00001220
Matt Kraai9bd49d62002-02-05 22:31:48 +00001221 for (i = optind; i < argc; i++) {
1222 char *path = NULL;
Eric Andersen96bcfd31999-11-12 01:30:18 +00001223
Manuel Novoa III df7bfb42005-03-02 04:10:46 +00001224 clear_bufs();
Matt Kraai9bd49d62002-02-05 22:31:48 +00001225 if (strcmp(argv[i], "-") == 0) {
1226 time_stamp = 0;
1227 ifile_size = -1L;
1228 inFileNum = STDIN_FILENO;
1229 outFileNum = STDOUT_FILENO;
1230 } else {
Bernhard Reutner-Fischerc2cb0f32006-04-13 12:45:04 +00001231 inFileNum = bb_xopen3(argv[i], O_RDONLY, 0);
Bernhard Reutner-Fischerdac7ff12006-04-12 17:55:51 +00001232 if (fstat(inFileNum, &statBuf) < 0)
Manuel Novoa III cad53642003-03-19 09:13:01 +00001233 bb_perror_msg_and_die("%s", argv[i]);
Matt Kraai9bd49d62002-02-05 22:31:48 +00001234 time_stamp = statBuf.st_ctime;
1235 ifile_size = statBuf.st_size;
Eric Andersen96bcfd31999-11-12 01:30:18 +00001236
Matt Kraai9bd49d62002-02-05 22:31:48 +00001237 if (!tostdout) {
1238 path = xmalloc(strlen(argv[i]) + 4);
1239 strcpy(path, argv[i]);
1240 strcat(path, ".gz");
Eric Andersen0dfac6b1999-11-11 05:46:32 +00001241
Matt Kraai9bd49d62002-02-05 22:31:48 +00001242 /* Open output file */
Bernhard Reutner-Fischer0b42a6a2005-10-07 11:34:50 +00001243#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) && defined O_NOFOLLOW
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001244 outFileNum =
1245 open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
Erik Andersen4d1d0111999-12-17 18:44:15 +00001246#else
Matt Kraai9bd49d62002-02-05 22:31:48 +00001247 outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL);
Erik Andersen4d1d0111999-12-17 18:44:15 +00001248#endif
Matt Kraai9bd49d62002-02-05 22:31:48 +00001249 if (outFileNum < 0) {
Manuel Novoa III cad53642003-03-19 09:13:01 +00001250 bb_perror_msg("%s", path);
Matt Kraai9bd49d62002-02-05 22:31:48 +00001251 free(path);
1252 continue;
1253 }
Erik Andersene49d5ec2000-02-08 19:58:47 +00001254
Matt Kraai9bd49d62002-02-05 22:31:48 +00001255 /* Set permissions on the file */
1256 fchmod(outFileNum, statBuf.st_mode);
1257 } else
1258 outFileNum = STDOUT_FILENO;
1259 }
Erik Andersene49d5ec2000-02-08 19:58:47 +00001260
Matt Kraaief8b1122002-03-22 22:55:51 +00001261 if (path == NULL && isatty(outFileNum) && force == 0) {
Manuel Novoa III cad53642003-03-19 09:13:01 +00001262 bb_error_msg
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001263 ("compressed data not written to a terminal. Use -f to force compression.");
Matt Kraai9bd49d62002-02-05 22:31:48 +00001264 free(path);
1265 continue;
1266 }
Erik Andersene49d5ec2000-02-08 19:58:47 +00001267
Matt Kraai9bd49d62002-02-05 22:31:48 +00001268 result = zip(inFileNum, outFileNum);
1269
1270 if (path != NULL) {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001271 close(inFileNum);
1272 close(outFileNum);
Matt Kraai9bd49d62002-02-05 22:31:48 +00001273
1274 /* Delete the original file */
1275 if (result == OK)
1276 delFileName = argv[i];
1277 else
1278 delFileName = path;
1279
1280 if (unlink(delFileName) < 0)
Manuel Novoa III cad53642003-03-19 09:13:01 +00001281 bb_perror_msg("%s", delFileName);
Matt Kraai9bd49d62002-02-05 22:31:48 +00001282 }
1283
1284 free(path);
1285 }
Eric Andersen0dfac6b1999-11-11 05:46:32 +00001286 }
Eric Andersen0dfac6b1999-11-11 05:46:32 +00001287
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001288 return (exit_code);
Eric Andersencc8ed391999-10-05 16:24:54 +00001289}
1290
Eric Andersencc8ed391999-10-05 16:24:54 +00001291/* trees.c -- output deflated data using Huffman coding
1292 * Copyright (C) 1992-1993 Jean-loup Gailly
1293 * This is free software; you can redistribute it and/or modify it under the
1294 * terms of the GNU General Public License, see the file COPYING.
1295 */
1296
1297/*
1298 * PURPOSE
1299 *
1300 * Encode various sets of source values using variable-length
1301 * binary code trees.
1302 *
1303 * DISCUSSION
1304 *
1305 * The PKZIP "deflation" process uses several Huffman trees. The more
1306 * common source values are represented by shorter bit sequences.
1307 *
1308 * Each code tree is stored in the ZIP file in a compressed form
1309 * which is itself a Huffman encoding of the lengths of
1310 * all the code strings (in ascending order by source values).
1311 * The actual code strings are reconstructed from the lengths in
1312 * the UNZIP process, as described in the "application note"
1313 * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1314 *
1315 * REFERENCES
1316 *
1317 * Lynch, Thomas J.
1318 * Data Compression: Techniques and Applications, pp. 53-55.
1319 * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
1320 *
1321 * Storer, James A.
1322 * Data Compression: Methods and Theory, pp. 49-50.
1323 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1324 *
1325 * Sedgewick, R.
1326 * Algorithms, p290.
1327 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1328 *
1329 * INTERFACE
1330 *
1331 * void ct_init (ush *attr, int *methodp)
1332 * Allocate the match buffer, initialize the various tables and save
1333 * the location of the internal file attribute (ascii/binary) and
1334 * method (DEFLATE/STORE)
1335 *
1336 * void ct_tally (int dist, int lc);
1337 * Save the match info and tally the frequency counts.
1338 *
1339 * long flush_block (char *buf, ulg stored_len, int eof)
1340 * Determine the best encoding for the current block: dynamic trees,
1341 * static trees or store, and output the encoded block to the zip
1342 * file. Returns the total compressed length for the file so far.
1343 *
1344 */
1345
Eric Andersencc8ed391999-10-05 16:24:54 +00001346/* ===========================================================================
1347 * Constants
1348 */
1349
1350#define MAX_BITS 15
1351/* All codes must not exceed MAX_BITS bits */
1352
1353#define MAX_BL_BITS 7
1354/* Bit length codes must not exceed MAX_BL_BITS bits */
1355
1356#define LENGTH_CODES 29
1357/* number of length codes, not counting the special END_BLOCK code */
1358
1359#define LITERALS 256
1360/* number of literal bytes 0..255 */
1361
1362#define END_BLOCK 256
1363/* end of block literal code */
1364
1365#define L_CODES (LITERALS+1+LENGTH_CODES)
1366/* number of Literal or Length codes, including the END_BLOCK code */
1367
1368#define D_CODES 30
1369/* number of distance codes */
1370
1371#define BL_CODES 19
1372/* number of codes used to transfer the bit lengths */
1373
Eric Andersen39eb0402001-08-22 04:15:47 +00001374typedef uch extra_bits_t;
Eric Andersencc8ed391999-10-05 16:24:54 +00001375
Eric Andersen39eb0402001-08-22 04:15:47 +00001376/* extra bits for each length code */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001377static const extra_bits_t extra_lbits[LENGTH_CODES]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001378 = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001379 4, 4, 5, 5, 5, 5, 0
1380};
Eric Andersencc8ed391999-10-05 16:24:54 +00001381
Eric Andersen39eb0402001-08-22 04:15:47 +00001382/* extra bits for each distance code */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001383static const extra_bits_t extra_dbits[D_CODES]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001384 = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001385 10, 10, 11, 11, 12, 12, 13, 13
1386};
Eric Andersencc8ed391999-10-05 16:24:54 +00001387
Eric Andersen39eb0402001-08-22 04:15:47 +00001388/* extra bits for each bit length code */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001389static const extra_bits_t extra_blbits[BL_CODES]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001390= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
Eric Andersencc8ed391999-10-05 16:24:54 +00001391
1392#define STORED_BLOCK 0
1393#define STATIC_TREES 1
1394#define DYN_TREES 2
1395/* The three kinds of block type */
1396
1397#ifndef LIT_BUFSIZE
1398# ifdef SMALL_MEM
1399# define LIT_BUFSIZE 0x2000
1400# else
1401# ifdef MEDIUM_MEM
1402# define LIT_BUFSIZE 0x4000
1403# else
1404# define LIT_BUFSIZE 0x8000
1405# endif
1406# endif
1407#endif
1408#ifndef DIST_BUFSIZE
1409# define DIST_BUFSIZE LIT_BUFSIZE
1410#endif
1411/* Sizes of match buffers for literals/lengths and distances. There are
1412 * 4 reasons for limiting LIT_BUFSIZE to 64K:
1413 * - frequencies can be kept in 16 bit counters
1414 * - if compression is not successful for the first block, all input data is
1415 * still in the window so we can still emit a stored block even when input
1416 * comes from standard input. (This can also be done for all blocks if
1417 * LIT_BUFSIZE is not greater than 32K.)
1418 * - if compression is not successful for a file smaller than 64K, we can
1419 * even emit a stored file instead of a stored block (saving 5 bytes).
1420 * - creating new Huffman trees less frequently may not provide fast
1421 * adaptation to changes in the input data statistics. (Take for
1422 * example a binary file with poorly compressible code followed by
1423 * a highly compressible string table.) Smaller buffer sizes give
1424 * fast adaptation but have of course the overhead of transmitting trees
1425 * more frequently.
1426 * - I can't count above 4
1427 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
1428 * memory at the expense of compression). Some optimizations would be possible
1429 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
1430 */
1431#if LIT_BUFSIZE > INBUFSIZ
Aaron Lehmannb9df4702001-12-06 03:22:43 +00001432#error cannot overlay l_buf and inbuf
Eric Andersencc8ed391999-10-05 16:24:54 +00001433#endif
Eric Andersencc8ed391999-10-05 16:24:54 +00001434#define REP_3_6 16
1435/* repeat previous bit length 3-6 times (2 bits of repeat count) */
Eric Andersencc8ed391999-10-05 16:24:54 +00001436#define REPZ_3_10 17
1437/* repeat a zero length 3-10 times (3 bits of repeat count) */
Eric Andersencc8ed391999-10-05 16:24:54 +00001438#define REPZ_11_138 18
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001439/* repeat a zero length 11-138 times (7 bits of repeat count) */
1440
1441/* ===========================================================================
Eric Andersencc8ed391999-10-05 16:24:54 +00001442 * Local data
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001443 */
1444
1445/* Data structure describing a single value and its code string. */
1446typedef struct ct_data {
Erik Andersene49d5ec2000-02-08 19:58:47 +00001447 union {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001448 ush freq; /* frequency count */
1449 ush code; /* bit string */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001450 } fc;
1451 union {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001452 ush dad; /* father node in Huffman tree */
1453 ush len; /* length of bit string */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001454 } dl;
Eric Andersencc8ed391999-10-05 16:24:54 +00001455} ct_data;
1456
1457#define Freq fc.freq
1458#define Code fc.code
1459#define Dad dl.dad
1460#define Len dl.len
1461
1462#define HEAP_SIZE (2*L_CODES+1)
1463/* maximum heap size */
1464
Eric Andersen3073dfb2001-07-02 17:57:32 +00001465static ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */
1466static ct_data dyn_dtree[2 * D_CODES + 1]; /* distance tree */
Eric Andersencc8ed391999-10-05 16:24:54 +00001467
Eric Andersen3073dfb2001-07-02 17:57:32 +00001468static ct_data static_ltree[L_CODES + 2];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001469
Eric Andersencc8ed391999-10-05 16:24:54 +00001470/* The static literal tree. Since the bit lengths are imposed, there is no
1471 * need for the L_CODES extra codes used during heap construction. However
1472 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1473 * below).
1474 */
1475
Eric Andersen3073dfb2001-07-02 17:57:32 +00001476static ct_data static_dtree[D_CODES];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001477
Eric Andersencc8ed391999-10-05 16:24:54 +00001478/* The static distance tree. (Actually a trivial tree since all codes use
1479 * 5 bits.)
1480 */
1481
Eric Andersen3073dfb2001-07-02 17:57:32 +00001482static ct_data bl_tree[2 * BL_CODES + 1];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001483
Eric Andersencc8ed391999-10-05 16:24:54 +00001484/* Huffman tree for the bit lengths */
1485
1486typedef struct tree_desc {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001487 ct_data *dyn_tree; /* the dynamic tree */
Eric Andersen3073dfb2001-07-02 17:57:32 +00001488 ct_data *static_tree; /* corresponding static tree or NULL */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001489 const extra_bits_t *extra_bits; /* extra bits for each code or NULL */
1490 int extra_base; /* base index for extra_bits */
1491 int elems; /* max number of elements in the tree */
1492 int max_length; /* max bit length for the codes */
1493 int max_code; /* largest code with non zero frequency */
Eric Andersencc8ed391999-10-05 16:24:54 +00001494} tree_desc;
1495
Eric Andersen3073dfb2001-07-02 17:57:32 +00001496static tree_desc l_desc =
Erik Andersene49d5ec2000-02-08 19:58:47 +00001497 { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES,
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001498 MAX_BITS, 0
1499};
Eric Andersencc8ed391999-10-05 16:24:54 +00001500
Eric Andersen3073dfb2001-07-02 17:57:32 +00001501static tree_desc d_desc =
Erik Andersene49d5ec2000-02-08 19:58:47 +00001502 { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 };
Eric Andersencc8ed391999-10-05 16:24:54 +00001503
Eric Andersen3073dfb2001-07-02 17:57:32 +00001504static tree_desc bl_desc =
1505 { bl_tree, (ct_data *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS,
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001506 0
1507};
Eric Andersencc8ed391999-10-05 16:24:54 +00001508
1509
Eric Andersen3073dfb2001-07-02 17:57:32 +00001510static ush bl_count[MAX_BITS + 1];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001511
Eric Andersencc8ed391999-10-05 16:24:54 +00001512/* number of codes at each bit length for an optimal tree */
1513
Eric Andersen3073dfb2001-07-02 17:57:32 +00001514static const uch bl_order[BL_CODES]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001515= { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
1516
Eric Andersencc8ed391999-10-05 16:24:54 +00001517/* The lengths of the bit length codes are sent in order of decreasing
1518 * probability, to avoid transmitting the lengths for unused bit length codes.
1519 */
1520
Eric Andersen3073dfb2001-07-02 17:57:32 +00001521static int heap[2 * L_CODES + 1]; /* heap used to build the Huffman trees */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001522static int heap_len; /* number of elements in the heap */
1523static int heap_max; /* element of largest frequency */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001524
Eric Andersencc8ed391999-10-05 16:24:54 +00001525/* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
1526 * The same heap array is used to build all trees.
1527 */
1528
Eric Andersen3073dfb2001-07-02 17:57:32 +00001529static uch depth[2 * L_CODES + 1];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001530
Eric Andersencc8ed391999-10-05 16:24:54 +00001531/* Depth of each subtree used as tie breaker for trees of equal frequency */
1532
Eric Andersen3073dfb2001-07-02 17:57:32 +00001533static uch length_code[MAX_MATCH - MIN_MATCH + 1];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001534
Eric Andersencc8ed391999-10-05 16:24:54 +00001535/* length code for each normalized match length (0 == MIN_MATCH) */
1536
Eric Andersen3073dfb2001-07-02 17:57:32 +00001537static uch dist_code[512];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001538
Eric Andersencc8ed391999-10-05 16:24:54 +00001539/* distance codes. The first 256 values correspond to the distances
1540 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1541 * the 15 bit distances.
1542 */
1543
Eric Andersen3073dfb2001-07-02 17:57:32 +00001544static int base_length[LENGTH_CODES];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001545
Eric Andersencc8ed391999-10-05 16:24:54 +00001546/* First normalized length for each code (0 = MIN_MATCH) */
1547
Eric Andersen3073dfb2001-07-02 17:57:32 +00001548static int base_dist[D_CODES];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001549
Eric Andersencc8ed391999-10-05 16:24:54 +00001550/* First normalized distance for each code (0 = distance of 1) */
1551
1552#define l_buf inbuf
1553/* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */
1554
1555/* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
1556
Eric Andersen3073dfb2001-07-02 17:57:32 +00001557static uch flag_buf[(LIT_BUFSIZE / 8)];
Erik Andersene49d5ec2000-02-08 19:58:47 +00001558
Eric Andersencc8ed391999-10-05 16:24:54 +00001559/* flag_buf is a bit array distinguishing literals from lengths in
1560 * l_buf, thus indicating the presence or absence of a distance.
1561 */
1562
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001563static unsigned last_lit; /* running index in l_buf */
1564static unsigned last_dist; /* running index in d_buf */
1565static unsigned last_flags; /* running index in flag_buf */
1566static uch flags; /* current flags not yet saved in flag_buf */
1567static uch flag_bit; /* current bit used in flags */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001568
Eric Andersencc8ed391999-10-05 16:24:54 +00001569/* bits are filled in flags starting at bit 0 (least significant).
1570 * Note: these flags are overkill in the current code since we don't
1571 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
1572 */
1573
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001574static ulg opt_len; /* bit length of current block with optimal trees */
1575static ulg static_len; /* bit length of current block with static trees */
Eric Andersencc8ed391999-10-05 16:24:54 +00001576
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001577static ulg compressed_len; /* total bit length of compressed file */
Eric Andersencc8ed391999-10-05 16:24:54 +00001578
Erik Andersene49d5ec2000-02-08 19:58:47 +00001579
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001580static ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
1581static int *file_method; /* pointer to DEFLATE or STORE */
Eric Andersencc8ed391999-10-05 16:24:54 +00001582
1583/* ===========================================================================
1584 * Local (static) routines in this file.
1585 */
1586
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001587static void init_block(void);
1588static void pqdownheap(ct_data * tree, int k);
1589static void gen_bitlen(tree_desc * desc);
1590static void gen_codes(ct_data * tree, int max_code);
1591static void build_tree(tree_desc * desc);
1592static void scan_tree(ct_data * tree, int max_code);
1593static void send_tree(ct_data * tree, int max_code);
1594static int build_bl_tree(void);
1595static void send_all_trees(int lcodes, int dcodes, int blcodes);
1596static void compress_block(ct_data * ltree, ct_data * dtree);
1597static void set_file_type(void);
Eric Andersencc8ed391999-10-05 16:24:54 +00001598
1599
1600#ifndef DEBUG
1601# define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
1602 /* Send a code of the given tree. c and tree must not have side effects */
1603
Erik Andersene49d5ec2000-02-08 19:58:47 +00001604#else /* DEBUG */
Eric Andersencc8ed391999-10-05 16:24:54 +00001605# define send_code(c, tree) \
Manuel Novoa III cad53642003-03-19 09:13:01 +00001606 { if (verbose>1) bb_error_msg("\ncd %3d ",(c)); \
Eric Andersencc8ed391999-10-05 16:24:54 +00001607 send_bits(tree[c].Code, tree[c].Len); }
1608#endif
1609
1610#define d_code(dist) \
1611 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1612/* Mapping from a distance to a distance code. dist is the distance - 1 and
1613 * must not have side effects. dist_code[256] and dist_code[257] are never
1614 * used.
1615 */
1616
Eric Andersencc8ed391999-10-05 16:24:54 +00001617/* the arguments must not have side effects */
1618
1619/* ===========================================================================
1620 * Allocate the match buffer, initialize the various tables and save the
1621 * location of the internal file attribute (ascii/binary) and method
1622 * (DEFLATE/STORE).
1623 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001624static void ct_init(ush * attr, int *methodp)
Eric Andersencc8ed391999-10-05 16:24:54 +00001625{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001626 int n; /* iterates over tree elements */
1627 int bits; /* bit counter */
1628 int length; /* length value */
1629 int code; /* code value */
1630 int dist; /* distance index */
Eric Andersencc8ed391999-10-05 16:24:54 +00001631
Erik Andersene49d5ec2000-02-08 19:58:47 +00001632 file_type = attr;
1633 file_method = methodp;
Eric Andersen3073dfb2001-07-02 17:57:32 +00001634 compressed_len = 0L;
Eric Andersencc8ed391999-10-05 16:24:54 +00001635
Erik Andersene49d5ec2000-02-08 19:58:47 +00001636 if (static_dtree[0].Len != 0)
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001637 return; /* ct_init already called */
Eric Andersencc8ed391999-10-05 16:24:54 +00001638
Erik Andersene49d5ec2000-02-08 19:58:47 +00001639 /* Initialize the mapping length (0..255) -> length code (0..28) */
1640 length = 0;
1641 for (code = 0; code < LENGTH_CODES - 1; code++) {
1642 base_length[code] = length;
1643 for (n = 0; n < (1 << extra_lbits[code]); n++) {
1644 length_code[length++] = (uch) code;
1645 }
1646 }
1647 Assert(length == 256, "ct_init: length != 256");
1648 /* Note that the length 255 (match length 258) can be represented
1649 * in two different ways: code 284 + 5 bits or code 285, so we
1650 * overwrite length_code[255] to use the best encoding:
1651 */
1652 length_code[length - 1] = (uch) code;
Eric Andersencc8ed391999-10-05 16:24:54 +00001653
Erik Andersene49d5ec2000-02-08 19:58:47 +00001654 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1655 dist = 0;
1656 for (code = 0; code < 16; code++) {
1657 base_dist[code] = dist;
1658 for (n = 0; n < (1 << extra_dbits[code]); n++) {
1659 dist_code[dist++] = (uch) code;
1660 }
1661 }
1662 Assert(dist == 256, "ct_init: dist != 256");
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001663 dist >>= 7; /* from now on, all distances are divided by 128 */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001664 for (; code < D_CODES; code++) {
1665 base_dist[code] = dist << 7;
1666 for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
1667 dist_code[256 + dist++] = (uch) code;
1668 }
1669 }
1670 Assert(dist == 256, "ct_init: 256+dist != 512");
Eric Andersencc8ed391999-10-05 16:24:54 +00001671
Erik Andersene49d5ec2000-02-08 19:58:47 +00001672 /* Construct the codes of the static literal tree */
1673 for (bits = 0; bits <= MAX_BITS; bits++)
1674 bl_count[bits] = 0;
1675 n = 0;
1676 while (n <= 143)
1677 static_ltree[n++].Len = 8, bl_count[8]++;
1678 while (n <= 255)
1679 static_ltree[n++].Len = 9, bl_count[9]++;
1680 while (n <= 279)
1681 static_ltree[n++].Len = 7, bl_count[7]++;
1682 while (n <= 287)
1683 static_ltree[n++].Len = 8, bl_count[8]++;
1684 /* Codes 286 and 287 do not exist, but we must include them in the
1685 * tree construction to get a canonical Huffman tree (longest code
1686 * all ones)
1687 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00001688 gen_codes((ct_data *) static_ltree, L_CODES + 1);
Eric Andersencc8ed391999-10-05 16:24:54 +00001689
Erik Andersene49d5ec2000-02-08 19:58:47 +00001690 /* The static distance tree is trivial: */
1691 for (n = 0; n < D_CODES; n++) {
1692 static_dtree[n].Len = 5;
1693 static_dtree[n].Code = bi_reverse(n, 5);
1694 }
1695
1696 /* Initialize the first block of the first file: */
1697 init_block();
Eric Andersencc8ed391999-10-05 16:24:54 +00001698}
1699
1700/* ===========================================================================
1701 * Initialize a new block.
1702 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +00001703static void init_block(void)
Eric Andersencc8ed391999-10-05 16:24:54 +00001704{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001705 int n; /* iterates over tree elements */
Eric Andersencc8ed391999-10-05 16:24:54 +00001706
Erik Andersene49d5ec2000-02-08 19:58:47 +00001707 /* Initialize the trees. */
1708 for (n = 0; n < L_CODES; n++)
1709 dyn_ltree[n].Freq = 0;
1710 for (n = 0; n < D_CODES; n++)
1711 dyn_dtree[n].Freq = 0;
1712 for (n = 0; n < BL_CODES; n++)
1713 bl_tree[n].Freq = 0;
Eric Andersencc8ed391999-10-05 16:24:54 +00001714
Erik Andersene49d5ec2000-02-08 19:58:47 +00001715 dyn_ltree[END_BLOCK].Freq = 1;
1716 opt_len = static_len = 0L;
1717 last_lit = last_dist = last_flags = 0;
1718 flags = 0;
1719 flag_bit = 1;
Eric Andersencc8ed391999-10-05 16:24:54 +00001720}
1721
1722#define SMALLEST 1
1723/* Index within the heap array of least frequent node in the Huffman tree */
1724
1725
1726/* ===========================================================================
1727 * Remove the smallest element from the heap and recreate the heap with
1728 * one less element. Updates heap and heap_len.
1729 */
1730#define pqremove(tree, top) \
1731{\
1732 top = heap[SMALLEST]; \
1733 heap[SMALLEST] = heap[heap_len--]; \
1734 pqdownheap(tree, SMALLEST); \
1735}
1736
1737/* ===========================================================================
1738 * Compares to subtrees, using the tree depth as tie breaker when
1739 * the subtrees have equal frequency. This minimizes the worst case length.
1740 */
1741#define smaller(tree, n, m) \
1742 (tree[n].Freq < tree[m].Freq || \
1743 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1744
1745/* ===========================================================================
1746 * Restore the heap property by moving down the tree starting at node k,
1747 * exchanging a node with the smallest of its two sons if necessary, stopping
1748 * when the heap property is re-established (each father smaller than its
1749 * two sons).
1750 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001751static void pqdownheap(ct_data * tree, int k)
Eric Andersencc8ed391999-10-05 16:24:54 +00001752{
Erik Andersene49d5ec2000-02-08 19:58:47 +00001753 int v = heap[k];
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001754 int j = k << 1; /* left son of k */
Eric Andersencc8ed391999-10-05 16:24:54 +00001755
Erik Andersene49d5ec2000-02-08 19:58:47 +00001756 while (j <= heap_len) {
1757 /* Set j to the smallest of the two sons: */
1758 if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
1759 j++;
Eric Andersencc8ed391999-10-05 16:24:54 +00001760
Erik Andersene49d5ec2000-02-08 19:58:47 +00001761 /* Exit if v is smaller than both sons */
1762 if (smaller(tree, v, heap[j]))
1763 break;
Eric Andersencc8ed391999-10-05 16:24:54 +00001764
Erik Andersene49d5ec2000-02-08 19:58:47 +00001765 /* Exchange v with the smallest son */
1766 heap[k] = heap[j];
1767 k = j;
1768
1769 /* And continue down the tree, setting j to the left son of k */
1770 j <<= 1;
1771 }
1772 heap[k] = v;
Eric Andersencc8ed391999-10-05 16:24:54 +00001773}
1774
1775/* ===========================================================================
1776 * Compute the optimal bit lengths for a tree and update the total bit length
1777 * for the current block.
1778 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1779 * above are the tree nodes sorted by increasing frequency.
1780 * OUT assertions: the field len is set to the optimal bit length, the
1781 * array bl_count contains the frequencies for each bit length.
1782 * The length opt_len is updated; static_len is also updated if stree is
1783 * not null.
1784 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001785static void gen_bitlen(tree_desc * desc)
Eric Andersencc8ed391999-10-05 16:24:54 +00001786{
Eric Andersen3073dfb2001-07-02 17:57:32 +00001787 ct_data *tree = desc->dyn_tree;
Eric Andersen39eb0402001-08-22 04:15:47 +00001788 const extra_bits_t *extra = desc->extra_bits;
Erik Andersene49d5ec2000-02-08 19:58:47 +00001789 int base = desc->extra_base;
1790 int max_code = desc->max_code;
1791 int max_length = desc->max_length;
Eric Andersen3073dfb2001-07-02 17:57:32 +00001792 ct_data *stree = desc->static_tree;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001793 int h; /* heap index */
1794 int n, m; /* iterate over the tree elements */
1795 int bits; /* bit length */
1796 int xbits; /* extra bits */
1797 ush f; /* frequency */
1798 int overflow = 0; /* number of elements with bit length too large */
Eric Andersencc8ed391999-10-05 16:24:54 +00001799
Erik Andersene49d5ec2000-02-08 19:58:47 +00001800 for (bits = 0; bits <= MAX_BITS; bits++)
1801 bl_count[bits] = 0;
Eric Andersencc8ed391999-10-05 16:24:54 +00001802
Erik Andersene49d5ec2000-02-08 19:58:47 +00001803 /* In a first pass, compute the optimal bit lengths (which may
1804 * overflow in the case of the bit length tree).
1805 */
1806 tree[heap[heap_max]].Len = 0; /* root of the heap */
Eric Andersencc8ed391999-10-05 16:24:54 +00001807
Erik Andersene49d5ec2000-02-08 19:58:47 +00001808 for (h = heap_max + 1; h < HEAP_SIZE; h++) {
1809 n = heap[h];
1810 bits = tree[tree[n].Dad].Len + 1;
1811 if (bits > max_length)
1812 bits = max_length, overflow++;
1813 tree[n].Len = (ush) bits;
1814 /* We overwrite tree[n].Dad which is no longer needed */
Eric Andersencc8ed391999-10-05 16:24:54 +00001815
Erik Andersene49d5ec2000-02-08 19:58:47 +00001816 if (n > max_code)
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001817 continue; /* not a leaf node */
Eric Andersencc8ed391999-10-05 16:24:54 +00001818
Erik Andersene49d5ec2000-02-08 19:58:47 +00001819 bl_count[bits]++;
1820 xbits = 0;
1821 if (n >= base)
1822 xbits = extra[n - base];
1823 f = tree[n].Freq;
1824 opt_len += (ulg) f *(bits + xbits);
Eric Andersencc8ed391999-10-05 16:24:54 +00001825
Erik Andersene49d5ec2000-02-08 19:58:47 +00001826 if (stree)
1827 static_len += (ulg) f *(stree[n].Len + xbits);
1828 }
1829 if (overflow == 0)
1830 return;
Eric Andersencc8ed391999-10-05 16:24:54 +00001831
Erik Andersene49d5ec2000-02-08 19:58:47 +00001832 Trace((stderr, "\nbit length overflow\n"));
1833 /* This happens for example on obj2 and pic of the Calgary corpus */
Eric Andersencc8ed391999-10-05 16:24:54 +00001834
Erik Andersene49d5ec2000-02-08 19:58:47 +00001835 /* Find the first bit length which could increase: */
1836 do {
1837 bits = max_length - 1;
1838 while (bl_count[bits] == 0)
1839 bits--;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001840 bl_count[bits]--; /* move one leaf down the tree */
Erik Andersene49d5ec2000-02-08 19:58:47 +00001841 bl_count[bits + 1] += 2; /* move one overflow item as its brother */
1842 bl_count[max_length]--;
1843 /* The brother of the overflow item also moves one step up,
1844 * but this does not affect bl_count[max_length]
1845 */
1846 overflow -= 2;
1847 } while (overflow > 0);
1848
1849 /* Now recompute all bit lengths, scanning in increasing frequency.
1850 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1851 * lengths instead of fixing only the wrong ones. This idea is taken
1852 * from 'ar' written by Haruhiko Okumura.)
1853 */
1854 for (bits = max_length; bits != 0; bits--) {
1855 n = bl_count[bits];
1856 while (n != 0) {
1857 m = heap[--h];
1858 if (m > max_code)
1859 continue;
1860 if (tree[m].Len != (unsigned) bits) {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001861 Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len,
Erik Andersene49d5ec2000-02-08 19:58:47 +00001862 bits));
1863 opt_len +=
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001864 ((long) bits - (long) tree[m].Len) * (long) tree[m].Freq;
Erik Andersene49d5ec2000-02-08 19:58:47 +00001865 tree[m].Len = (ush) bits;
1866 }
1867 n--;
1868 }
1869 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001870}
1871
1872/* ===========================================================================
1873 * Generate the codes for a given tree and bit counts (which need not be
1874 * optimal).
1875 * IN assertion: the array bl_count contains the bit length statistics for
1876 * the given tree and the field len is set for all tree elements.
1877 * OUT assertion: the field code is set for all tree elements of non
1878 * zero code length.
1879 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001880static void gen_codes(ct_data * tree, int max_code)
Eric Andersencc8ed391999-10-05 16:24:54 +00001881{
Erik Andersene49d5ec2000-02-08 19:58:47 +00001882 ush next_code[MAX_BITS + 1]; /* next code value for each bit length */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001883 ush code = 0; /* running code value */
1884 int bits; /* bit index */
1885 int n; /* code index */
Eric Andersencc8ed391999-10-05 16:24:54 +00001886
Erik Andersene49d5ec2000-02-08 19:58:47 +00001887 /* The distribution counts are first used to generate the code values
1888 * without bit reversal.
1889 */
1890 for (bits = 1; bits <= MAX_BITS; bits++) {
1891 next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
1892 }
1893 /* Check that the bit counts in bl_count are consistent. The last code
1894 * must be all ones.
1895 */
1896 Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
1897 "inconsistent bit counts");
1898 Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
Eric Andersencc8ed391999-10-05 16:24:54 +00001899
Erik Andersene49d5ec2000-02-08 19:58:47 +00001900 for (n = 0; n <= max_code; n++) {
1901 int len = tree[n].Len;
Eric Andersencc8ed391999-10-05 16:24:54 +00001902
Erik Andersene49d5ec2000-02-08 19:58:47 +00001903 if (len == 0)
1904 continue;
1905 /* Now reverse the bits */
1906 tree[n].Code = bi_reverse(next_code[len]++, len);
1907
1908 Tracec(tree != static_ltree,
1909 (stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
1910 (isgraph(n) ? n : ' '), len, tree[n].Code,
1911 next_code[len] - 1));
1912 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001913}
1914
1915/* ===========================================================================
1916 * Construct one Huffman tree and assigns the code bit strings and lengths.
1917 * Update the total bit length for the current block.
1918 * IN assertion: the field freq is set for all tree elements.
1919 * OUT assertions: the fields len and code are set to the optimal bit length
1920 * and corresponding code. The length opt_len is updated; static_len is
1921 * also updated if stree is not null. The field max_code is set.
1922 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001923static void build_tree(tree_desc * desc)
Eric Andersencc8ed391999-10-05 16:24:54 +00001924{
Eric Andersen3073dfb2001-07-02 17:57:32 +00001925 ct_data *tree = desc->dyn_tree;
1926 ct_data *stree = desc->static_tree;
Erik Andersene49d5ec2000-02-08 19:58:47 +00001927 int elems = desc->elems;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001928 int n, m; /* iterate over heap elements */
1929 int max_code = -1; /* largest code with non zero frequency */
1930 int node = elems; /* next internal node of the tree */
Eric Andersencc8ed391999-10-05 16:24:54 +00001931
Erik Andersene49d5ec2000-02-08 19:58:47 +00001932 /* Construct the initial heap, with least frequent element in
1933 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1934 * heap[0] is not used.
1935 */
1936 heap_len = 0, heap_max = HEAP_SIZE;
Eric Andersencc8ed391999-10-05 16:24:54 +00001937
Erik Andersene49d5ec2000-02-08 19:58:47 +00001938 for (n = 0; n < elems; n++) {
1939 if (tree[n].Freq != 0) {
1940 heap[++heap_len] = max_code = n;
1941 depth[n] = 0;
1942 } else {
1943 tree[n].Len = 0;
1944 }
1945 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001946
Erik Andersene49d5ec2000-02-08 19:58:47 +00001947 /* The pkzip format requires that at least one distance code exists,
1948 * and that at least one bit should be sent even if there is only one
1949 * possible code. So to avoid special checks later on we force at least
1950 * two codes of non zero frequency.
1951 */
1952 while (heap_len < 2) {
1953 int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
Eric Andersencc8ed391999-10-05 16:24:54 +00001954
Erik Andersene49d5ec2000-02-08 19:58:47 +00001955 tree[new].Freq = 1;
1956 depth[new] = 0;
1957 opt_len--;
1958 if (stree)
1959 static_len -= stree[new].Len;
1960 /* new is 0 or 1 so it does not have extra bits */
1961 }
1962 desc->max_code = max_code;
Eric Andersencc8ed391999-10-05 16:24:54 +00001963
Erik Andersene49d5ec2000-02-08 19:58:47 +00001964 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
1965 * establish sub-heaps of increasing lengths:
1966 */
1967 for (n = heap_len / 2; n >= 1; n--)
1968 pqdownheap(tree, n);
Eric Andersencc8ed391999-10-05 16:24:54 +00001969
Erik Andersene49d5ec2000-02-08 19:58:47 +00001970 /* Construct the Huffman tree by repeatedly combining the least two
1971 * frequent nodes.
1972 */
1973 do {
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001974 pqremove(tree, n); /* n = node of least frequency */
1975 m = heap[SMALLEST]; /* m = node of next least frequency */
Eric Andersencc8ed391999-10-05 16:24:54 +00001976
Erik Andersene49d5ec2000-02-08 19:58:47 +00001977 heap[--heap_max] = n; /* keep the nodes sorted by frequency */
1978 heap[--heap_max] = m;
1979
1980 /* Create a new node father of n and m */
1981 tree[node].Freq = tree[n].Freq + tree[m].Freq;
1982 depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
1983 tree[n].Dad = tree[m].Dad = (ush) node;
Eric Andersencc8ed391999-10-05 16:24:54 +00001984#ifdef DUMP_BL_TREE
Erik Andersene49d5ec2000-02-08 19:58:47 +00001985 if (tree == bl_tree) {
Manuel Novoa III cad53642003-03-19 09:13:01 +00001986 bb_error_msg("\nnode %d(%d), sons %d(%d) %d(%d)",
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00001987 node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
Erik Andersene49d5ec2000-02-08 19:58:47 +00001988 }
Eric Andersencc8ed391999-10-05 16:24:54 +00001989#endif
Erik Andersene49d5ec2000-02-08 19:58:47 +00001990 /* and insert the new node in the heap */
1991 heap[SMALLEST] = node++;
1992 pqdownheap(tree, SMALLEST);
Eric Andersencc8ed391999-10-05 16:24:54 +00001993
Erik Andersene49d5ec2000-02-08 19:58:47 +00001994 } while (heap_len >= 2);
Eric Andersencc8ed391999-10-05 16:24:54 +00001995
Erik Andersene49d5ec2000-02-08 19:58:47 +00001996 heap[--heap_max] = heap[SMALLEST];
Eric Andersencc8ed391999-10-05 16:24:54 +00001997
Erik Andersene49d5ec2000-02-08 19:58:47 +00001998 /* At this point, the fields freq and dad are set. We can now
1999 * generate the bit lengths.
2000 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002001 gen_bitlen((tree_desc *) desc);
Eric Andersencc8ed391999-10-05 16:24:54 +00002002
Erik Andersene49d5ec2000-02-08 19:58:47 +00002003 /* The field len is now set, we can generate the bit codes */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002004 gen_codes((ct_data *) tree, max_code);
Eric Andersencc8ed391999-10-05 16:24:54 +00002005}
2006
2007/* ===========================================================================
2008 * Scan a literal or distance tree to determine the frequencies of the codes
2009 * in the bit length tree. Updates opt_len to take into account the repeat
2010 * counts. (The contribution of the bit length codes will be added later
2011 * during the construction of bl_tree.)
2012 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002013static void scan_tree(ct_data * tree, int max_code)
Eric Andersencc8ed391999-10-05 16:24:54 +00002014{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002015 int n; /* iterates over all tree elements */
2016 int prevlen = -1; /* last emitted length */
2017 int curlen; /* length of current code */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002018 int nextlen = tree[0].Len; /* length of next code */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002019 int count = 0; /* repeat count of the current code */
2020 int max_count = 7; /* max repeat count */
2021 int min_count = 4; /* min repeat count */
Eric Andersencc8ed391999-10-05 16:24:54 +00002022
Erik Andersene49d5ec2000-02-08 19:58:47 +00002023 if (nextlen == 0)
2024 max_count = 138, min_count = 3;
2025 tree[max_code + 1].Len = (ush) 0xffff; /* guard */
Eric Andersencc8ed391999-10-05 16:24:54 +00002026
Erik Andersene49d5ec2000-02-08 19:58:47 +00002027 for (n = 0; n <= max_code; n++) {
2028 curlen = nextlen;
2029 nextlen = tree[n + 1].Len;
2030 if (++count < max_count && curlen == nextlen) {
2031 continue;
2032 } else if (count < min_count) {
2033 bl_tree[curlen].Freq += count;
2034 } else if (curlen != 0) {
2035 if (curlen != prevlen)
2036 bl_tree[curlen].Freq++;
2037 bl_tree[REP_3_6].Freq++;
2038 } else if (count <= 10) {
2039 bl_tree[REPZ_3_10].Freq++;
2040 } else {
2041 bl_tree[REPZ_11_138].Freq++;
2042 }
2043 count = 0;
2044 prevlen = curlen;
2045 if (nextlen == 0) {
2046 max_count = 138, min_count = 3;
2047 } else if (curlen == nextlen) {
2048 max_count = 6, min_count = 3;
2049 } else {
2050 max_count = 7, min_count = 4;
2051 }
2052 }
Eric Andersencc8ed391999-10-05 16:24:54 +00002053}
2054
2055/* ===========================================================================
2056 * Send a literal or distance tree in compressed form, using the codes in
2057 * bl_tree.
2058 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002059static void send_tree(ct_data * tree, int max_code)
Eric Andersencc8ed391999-10-05 16:24:54 +00002060{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002061 int n; /* iterates over all tree elements */
2062 int prevlen = -1; /* last emitted length */
2063 int curlen; /* length of current code */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002064 int nextlen = tree[0].Len; /* length of next code */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002065 int count = 0; /* repeat count of the current code */
2066 int max_count = 7; /* max repeat count */
2067 int min_count = 4; /* min repeat count */
Eric Andersencc8ed391999-10-05 16:24:54 +00002068
Erik Andersene49d5ec2000-02-08 19:58:47 +00002069/* tree[max_code+1].Len = -1; *//* guard already set */
2070 if (nextlen == 0)
2071 max_count = 138, min_count = 3;
Eric Andersencc8ed391999-10-05 16:24:54 +00002072
Erik Andersene49d5ec2000-02-08 19:58:47 +00002073 for (n = 0; n <= max_code; n++) {
2074 curlen = nextlen;
2075 nextlen = tree[n + 1].Len;
2076 if (++count < max_count && curlen == nextlen) {
2077 continue;
2078 } else if (count < min_count) {
2079 do {
2080 send_code(curlen, bl_tree);
2081 } while (--count != 0);
Eric Andersencc8ed391999-10-05 16:24:54 +00002082
Erik Andersene49d5ec2000-02-08 19:58:47 +00002083 } else if (curlen != 0) {
2084 if (curlen != prevlen) {
2085 send_code(curlen, bl_tree);
2086 count--;
2087 }
2088 Assert(count >= 3 && count <= 6, " 3_6?");
2089 send_code(REP_3_6, bl_tree);
2090 send_bits(count - 3, 2);
Eric Andersencc8ed391999-10-05 16:24:54 +00002091
Erik Andersene49d5ec2000-02-08 19:58:47 +00002092 } else if (count <= 10) {
2093 send_code(REPZ_3_10, bl_tree);
2094 send_bits(count - 3, 3);
Eric Andersencc8ed391999-10-05 16:24:54 +00002095
Erik Andersene49d5ec2000-02-08 19:58:47 +00002096 } else {
2097 send_code(REPZ_11_138, bl_tree);
2098 send_bits(count - 11, 7);
2099 }
2100 count = 0;
2101 prevlen = curlen;
2102 if (nextlen == 0) {
2103 max_count = 138, min_count = 3;
2104 } else if (curlen == nextlen) {
2105 max_count = 6, min_count = 3;
2106 } else {
2107 max_count = 7, min_count = 4;
2108 }
2109 }
Eric Andersencc8ed391999-10-05 16:24:54 +00002110}
2111
2112/* ===========================================================================
2113 * Construct the Huffman tree for the bit lengths and return the index in
2114 * bl_order of the last bit length code to send.
2115 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +00002116static int build_bl_tree(void)
Eric Andersencc8ed391999-10-05 16:24:54 +00002117{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002118 int max_blindex; /* index of last bit length code of non zero freq */
Eric Andersencc8ed391999-10-05 16:24:54 +00002119
Erik Andersene49d5ec2000-02-08 19:58:47 +00002120 /* Determine the bit length frequencies for literal and distance trees */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002121 scan_tree((ct_data *) dyn_ltree, l_desc.max_code);
2122 scan_tree((ct_data *) dyn_dtree, d_desc.max_code);
Eric Andersencc8ed391999-10-05 16:24:54 +00002123
Erik Andersene49d5ec2000-02-08 19:58:47 +00002124 /* Build the bit length tree: */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002125 build_tree((tree_desc *) (&bl_desc));
Erik Andersene49d5ec2000-02-08 19:58:47 +00002126 /* opt_len now includes the length of the tree representations, except
2127 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2128 */
Eric Andersencc8ed391999-10-05 16:24:54 +00002129
Erik Andersene49d5ec2000-02-08 19:58:47 +00002130 /* Determine the number of bit length codes to send. The pkzip format
2131 * requires that at least 4 bit length codes be sent. (appnote.txt says
2132 * 3 but the actual value used is 4.)
2133 */
2134 for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
2135 if (bl_tree[bl_order[max_blindex]].Len != 0)
2136 break;
2137 }
2138 /* Update opt_len to include the bit length tree and counts */
2139 opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002140 Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
Eric Andersencc8ed391999-10-05 16:24:54 +00002141
Erik Andersene49d5ec2000-02-08 19:58:47 +00002142 return max_blindex;
Eric Andersencc8ed391999-10-05 16:24:54 +00002143}
2144
2145/* ===========================================================================
2146 * Send the header for a block using dynamic Huffman trees: the counts, the
2147 * lengths of the bit length codes, the literal tree and the distance tree.
2148 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2149 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002150static void send_all_trees(int lcodes, int dcodes, int blcodes)
Eric Andersencc8ed391999-10-05 16:24:54 +00002151{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002152 int rank; /* index in bl_order */
Eric Andersencc8ed391999-10-05 16:24:54 +00002153
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002154 Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
Erik Andersene49d5ec2000-02-08 19:58:47 +00002155 Assert(lcodes <= L_CODES && dcodes <= D_CODES
2156 && blcodes <= BL_CODES, "too many codes");
2157 Tracev((stderr, "\nbl counts: "));
2158 send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */
2159 send_bits(dcodes - 1, 5);
2160 send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */
2161 for (rank = 0; rank < blcodes; rank++) {
2162 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2163 send_bits(bl_tree[bl_order[rank]].Len, 3);
2164 }
2165 Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
Eric Andersencc8ed391999-10-05 16:24:54 +00002166
Eric Andersen3073dfb2001-07-02 17:57:32 +00002167 send_tree((ct_data *) dyn_ltree, lcodes - 1); /* send the literal tree */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002168 Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
Eric Andersencc8ed391999-10-05 16:24:54 +00002169
Eric Andersen3073dfb2001-07-02 17:57:32 +00002170 send_tree((ct_data *) dyn_dtree, dcodes - 1); /* send the distance tree */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002171 Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
Eric Andersencc8ed391999-10-05 16:24:54 +00002172}
2173
2174/* ===========================================================================
2175 * Determine the best encoding for the current block: dynamic trees, static
2176 * trees or store, and output the encoded block to the zip file. This function
2177 * returns the total compressed length for the file so far.
2178 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002179static ulg flush_block(char *buf, ulg stored_len, int eof)
Eric Andersencc8ed391999-10-05 16:24:54 +00002180{
Erik Andersene49d5ec2000-02-08 19:58:47 +00002181 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002182 int max_blindex; /* index of last bit length code of non zero freq */
Eric Andersencc8ed391999-10-05 16:24:54 +00002183
Erik Andersene49d5ec2000-02-08 19:58:47 +00002184 flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
Eric Andersencc8ed391999-10-05 16:24:54 +00002185
Erik Andersene49d5ec2000-02-08 19:58:47 +00002186 /* Check if the file is ascii or binary */
2187 if (*file_type == (ush) UNKNOWN)
2188 set_file_type();
Eric Andersencc8ed391999-10-05 16:24:54 +00002189
Erik Andersene49d5ec2000-02-08 19:58:47 +00002190 /* Construct the literal and distance trees */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002191 build_tree((tree_desc *) (&l_desc));
Erik Andersene49d5ec2000-02-08 19:58:47 +00002192 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
Eric Andersencc8ed391999-10-05 16:24:54 +00002193
Eric Andersen3073dfb2001-07-02 17:57:32 +00002194 build_tree((tree_desc *) (&d_desc));
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002195 Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
Erik Andersene49d5ec2000-02-08 19:58:47 +00002196 /* At this point, opt_len and static_len are the total bit lengths of
2197 * the compressed block data, excluding the tree representations.
2198 */
Eric Andersencc8ed391999-10-05 16:24:54 +00002199
Erik Andersene49d5ec2000-02-08 19:58:47 +00002200 /* Build the bit length tree for the above two trees, and get the index
2201 * in bl_order of the last bit length code to send.
2202 */
2203 max_blindex = build_bl_tree();
Eric Andersencc8ed391999-10-05 16:24:54 +00002204
Erik Andersene49d5ec2000-02-08 19:58:47 +00002205 /* Determine the best encoding. Compute first the block length in bytes */
2206 opt_lenb = (opt_len + 3 + 7) >> 3;
2207 static_lenb = (static_len + 3 + 7) >> 3;
Eric Andersencc8ed391999-10-05 16:24:54 +00002208
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002209 Trace((stderr,
Erik Andersene49d5ec2000-02-08 19:58:47 +00002210 "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2211 opt_lenb, opt_len, static_lenb, static_len, stored_len,
2212 last_lit, last_dist));
Eric Andersencc8ed391999-10-05 16:24:54 +00002213
Erik Andersene49d5ec2000-02-08 19:58:47 +00002214 if (static_lenb <= opt_lenb)
2215 opt_lenb = static_lenb;
Eric Andersencc8ed391999-10-05 16:24:54 +00002216
Erik Andersene49d5ec2000-02-08 19:58:47 +00002217 /* If compression failed and this is the first and last block,
2218 * and if the zip file can be seeked (to rewrite the local header),
2219 * the whole file is transformed into a stored file:
2220 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002221 if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
Erik Andersene49d5ec2000-02-08 19:58:47 +00002222 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2223 if (buf == (char *) 0)
Manuel Novoa III cad53642003-03-19 09:13:01 +00002224 bb_error_msg("block vanished");
Eric Andersencc8ed391999-10-05 16:24:54 +00002225
Erik Andersene49d5ec2000-02-08 19:58:47 +00002226 copy_block(buf, (unsigned) stored_len, 0); /* without header */
2227 compressed_len = stored_len << 3;
2228 *file_method = STORED;
Eric Andersencc8ed391999-10-05 16:24:54 +00002229
Erik Andersene49d5ec2000-02-08 19:58:47 +00002230 } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
2231 /* 4: two words for the lengths */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002232 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2233 * Otherwise we can't have processed more than WSIZE input bytes since
2234 * the last block flush, because compression would have been
2235 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2236 * transform a block into a stored block.
2237 */
2238 send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */
2239 compressed_len = (compressed_len + 3 + 7) & ~7L;
2240 compressed_len += (stored_len + 4) << 3;
Eric Andersencc8ed391999-10-05 16:24:54 +00002241
Erik Andersene49d5ec2000-02-08 19:58:47 +00002242 copy_block(buf, (unsigned) stored_len, 1); /* with header */
Eric Andersencc8ed391999-10-05 16:24:54 +00002243
Erik Andersene49d5ec2000-02-08 19:58:47 +00002244 } else if (static_lenb == opt_lenb) {
Erik Andersene49d5ec2000-02-08 19:58:47 +00002245 send_bits((STATIC_TREES << 1) + eof, 3);
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002246 compress_block((ct_data *) static_ltree, (ct_data *) static_dtree);
Erik Andersene49d5ec2000-02-08 19:58:47 +00002247 compressed_len += 3 + static_len;
2248 } else {
2249 send_bits((DYN_TREES << 1) + eof, 3);
2250 send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1,
2251 max_blindex + 1);
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002252 compress_block((ct_data *) dyn_ltree, (ct_data *) dyn_dtree);
Erik Andersene49d5ec2000-02-08 19:58:47 +00002253 compressed_len += 3 + opt_len;
2254 }
2255 Assert(compressed_len == bits_sent, "bad compressed size");
2256 init_block();
Eric Andersencc8ed391999-10-05 16:24:54 +00002257
Erik Andersene49d5ec2000-02-08 19:58:47 +00002258 if (eof) {
Erik Andersene49d5ec2000-02-08 19:58:47 +00002259 bi_windup();
2260 compressed_len += 7; /* align on byte boundary */
2261 }
2262 Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
2263 compressed_len - 7 * eof));
Eric Andersencc8ed391999-10-05 16:24:54 +00002264
Erik Andersene49d5ec2000-02-08 19:58:47 +00002265 return compressed_len >> 3;
Eric Andersencc8ed391999-10-05 16:24:54 +00002266}
2267
2268/* ===========================================================================
2269 * Save the match info and tally the frequency counts. Return true if
2270 * the current block must be flushed.
2271 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002272static int ct_tally(int dist, int lc)
Eric Andersencc8ed391999-10-05 16:24:54 +00002273{
Erik Andersene49d5ec2000-02-08 19:58:47 +00002274 l_buf[last_lit++] = (uch) lc;
2275 if (dist == 0) {
2276 /* lc is the unmatched char */
2277 dyn_ltree[lc].Freq++;
2278 } else {
2279 /* Here, lc is the match length - MIN_MATCH */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002280 dist--; /* dist = match distance - 1 */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002281 Assert((ush) dist < (ush) MAX_DIST &&
2282 (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) &&
2283 (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match");
Eric Andersencc8ed391999-10-05 16:24:54 +00002284
Erik Andersene49d5ec2000-02-08 19:58:47 +00002285 dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
2286 dyn_dtree[d_code(dist)].Freq++;
Eric Andersencc8ed391999-10-05 16:24:54 +00002287
Erik Andersene49d5ec2000-02-08 19:58:47 +00002288 d_buf[last_dist++] = (ush) dist;
2289 flags |= flag_bit;
2290 }
2291 flag_bit <<= 1;
Eric Andersencc8ed391999-10-05 16:24:54 +00002292
Erik Andersene49d5ec2000-02-08 19:58:47 +00002293 /* Output the flags if they fill a byte: */
2294 if ((last_lit & 7) == 0) {
2295 flag_buf[last_flags++] = flags;
2296 flags = 0, flag_bit = 1;
2297 }
2298 /* Try to guess if it is profitable to stop the current block here */
2299 if ((last_lit & 0xfff) == 0) {
2300 /* Compute an upper bound for the compressed length */
2301 ulg out_length = (ulg) last_lit * 8L;
2302 ulg in_length = (ulg) strstart - block_start;
2303 int dcode;
2304
2305 for (dcode = 0; dcode < D_CODES; dcode++) {
2306 out_length +=
2307 (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
2308 }
2309 out_length >>= 3;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002310 Trace((stderr,
Erik Andersene49d5ec2000-02-08 19:58:47 +00002311 "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
2312 last_lit, last_dist, in_length, out_length,
2313 100L - out_length * 100L / in_length));
2314 if (last_dist < last_lit / 2 && out_length < in_length / 2)
2315 return 1;
2316 }
2317 return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE);
2318 /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
2319 * on 16 bit machines and because stored blocks are restricted to
2320 * 64K-1 bytes.
2321 */
Eric Andersencc8ed391999-10-05 16:24:54 +00002322}
2323
2324/* ===========================================================================
2325 * Send the block data compressed using the given Huffman trees
2326 */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002327static void compress_block(ct_data * ltree, ct_data * dtree)
Eric Andersencc8ed391999-10-05 16:24:54 +00002328{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002329 unsigned dist; /* distance of matched string */
2330 int lc; /* match length or unmatched char (if dist == 0) */
2331 unsigned lx = 0; /* running index in l_buf */
2332 unsigned dx = 0; /* running index in d_buf */
2333 unsigned fx = 0; /* running index in flag_buf */
2334 uch flag = 0; /* current flags */
2335 unsigned code; /* the code to send */
2336 int extra; /* number of extra bits to send */
Eric Andersencc8ed391999-10-05 16:24:54 +00002337
Erik Andersene49d5ec2000-02-08 19:58:47 +00002338 if (last_lit != 0)
2339 do {
2340 if ((lx & 7) == 0)
2341 flag = flag_buf[fx++];
2342 lc = l_buf[lx++];
2343 if ((flag & 1) == 0) {
2344 send_code(lc, ltree); /* send a literal byte */
2345 Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
2346 } else {
2347 /* Here, lc is the match length - MIN_MATCH */
2348 code = length_code[lc];
2349 send_code(code + LITERALS + 1, ltree); /* send the length code */
2350 extra = extra_lbits[code];
2351 if (extra != 0) {
2352 lc -= base_length[code];
2353 send_bits(lc, extra); /* send the extra length bits */
2354 }
2355 dist = d_buf[dx++];
2356 /* Here, dist is the match distance - 1 */
2357 code = d_code(dist);
2358 Assert(code < D_CODES, "bad d_code");
Eric Andersencc8ed391999-10-05 16:24:54 +00002359
Erik Andersene49d5ec2000-02-08 19:58:47 +00002360 send_code(code, dtree); /* send the distance code */
2361 extra = extra_dbits[code];
2362 if (extra != 0) {
2363 dist -= base_dist[code];
2364 send_bits(dist, extra); /* send the extra distance bits */
2365 }
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002366 } /* literal or match pair ? */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002367 flag >>= 1;
2368 } while (lx < last_lit);
Eric Andersencc8ed391999-10-05 16:24:54 +00002369
Erik Andersene49d5ec2000-02-08 19:58:47 +00002370 send_code(END_BLOCK, ltree);
Eric Andersencc8ed391999-10-05 16:24:54 +00002371}
2372
2373/* ===========================================================================
2374 * Set the file type to ASCII or BINARY, using a crude approximation:
2375 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2376 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2377 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2378 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +00002379static void set_file_type(void)
Eric Andersencc8ed391999-10-05 16:24:54 +00002380{
Erik Andersene49d5ec2000-02-08 19:58:47 +00002381 int n = 0;
2382 unsigned ascii_freq = 0;
2383 unsigned bin_freq = 0;
2384
2385 while (n < 7)
2386 bin_freq += dyn_ltree[n++].Freq;
2387 while (n < 128)
2388 ascii_freq += dyn_ltree[n++].Freq;
2389 while (n < LITERALS)
2390 bin_freq += dyn_ltree[n++].Freq;
2391 *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
2392 if (*file_type == BINARY && translate_eol) {
Manuel Novoa III cad53642003-03-19 09:13:01 +00002393 bb_error_msg("-l used on binary file");
Erik Andersene49d5ec2000-02-08 19:58:47 +00002394 }
Eric Andersencc8ed391999-10-05 16:24:54 +00002395}
Erik Andersene49d5ec2000-02-08 19:58:47 +00002396
Eric Andersencc8ed391999-10-05 16:24:54 +00002397/* zip.c -- compress files to the gzip or pkzip format
2398 * Copyright (C) 1992-1993 Jean-loup Gailly
2399 * This is free software; you can redistribute it and/or modify it under the
2400 * terms of the GNU General Public License, see the file COPYING.
2401 */
2402
Eric Andersencc8ed391999-10-05 16:24:54 +00002403
Rob Landleyc57ec372006-04-10 17:07:15 +00002404static uint32_t crc; /* crc on uncompressed file data */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002405static long header_bytes; /* number of bytes in gzip header */
Eric Andersencc8ed391999-10-05 16:24:54 +00002406
Eric Andersen39eb0402001-08-22 04:15:47 +00002407static void put_long(ulg n)
2408{
Aaron Lehmannb9df4702001-12-06 03:22:43 +00002409 put_short((n) & 0xffff);
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002410 put_short(((ulg) (n)) >> 16);
Eric Andersen39eb0402001-08-22 04:15:47 +00002411}
2412
2413/* put_header_byte is used for the compressed output
2414 * - for the initial 4 bytes that can't overflow the buffer.
2415 */
2416#define put_header_byte(c) {outbuf[outcnt++]=(uch)(c);}
2417
Eric Andersencc8ed391999-10-05 16:24:54 +00002418/* ===========================================================================
2419 * Deflate in to out.
2420 * IN assertions: the input and output buffers are cleared.
2421 * The variables time_stamp and save_orig_name are initialized.
2422 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002423static int zip(int in, int out)
Eric Andersencc8ed391999-10-05 16:24:54 +00002424{
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002425 uch my_flags = 0; /* general purpose bit flags */
2426 ush attr = 0; /* ascii/binary flag */
2427 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
Eric Andersencc8ed391999-10-05 16:24:54 +00002428
Erik Andersene49d5ec2000-02-08 19:58:47 +00002429 ifd = in;
2430 ofd = out;
2431 outcnt = 0;
Eric Andersencc8ed391999-10-05 16:24:54 +00002432
Erik Andersene49d5ec2000-02-08 19:58:47 +00002433 /* Write the header to the gzip file. See algorithm.doc for the format */
Eric Andersencc8ed391999-10-05 16:24:54 +00002434
Eric Andersen96bcfd31999-11-12 01:30:18 +00002435
Erik Andersene49d5ec2000-02-08 19:58:47 +00002436 method = DEFLATED;
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002437 put_header_byte(GZIP_MAGIC[0]); /* magic header */
Eric Andersen39eb0402001-08-22 04:15:47 +00002438 put_header_byte(GZIP_MAGIC[1]);
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002439 put_header_byte(DEFLATED); /* compression method */
Eric Andersencc8ed391999-10-05 16:24:54 +00002440
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002441 put_header_byte(my_flags); /* general flags */
Erik Andersene49d5ec2000-02-08 19:58:47 +00002442 put_long(time_stamp);
Eric Andersencc8ed391999-10-05 16:24:54 +00002443
Erik Andersene49d5ec2000-02-08 19:58:47 +00002444 /* Write deflated file to zip file */
2445 crc = updcrc(0, 0);
Eric Andersencc8ed391999-10-05 16:24:54 +00002446
Erik Andersene49d5ec2000-02-08 19:58:47 +00002447 bi_init(out);
2448 ct_init(&attr, &method);
2449 lm_init(&deflate_flags);
Eric Andersencc8ed391999-10-05 16:24:54 +00002450
Erik Andersene49d5ec2000-02-08 19:58:47 +00002451 put_byte((uch) deflate_flags); /* extra flags */
Glenn L McGrathd827e8b2002-08-22 13:21:26 +00002452 put_byte(OS_CODE); /* OS identifier */
Eric Andersencc8ed391999-10-05 16:24:54 +00002453
Erik Andersene49d5ec2000-02-08 19:58:47 +00002454 header_bytes = (long) outcnt;
Eric Andersencc8ed391999-10-05 16:24:54 +00002455
Erik Andersene49d5ec2000-02-08 19:58:47 +00002456 (void) deflate();
Eric Andersencc8ed391999-10-05 16:24:54 +00002457
Erik Andersene49d5ec2000-02-08 19:58:47 +00002458 /* Write the crc and uncompressed size */
2459 put_long(crc);
2460 put_long(isize);
2461 header_bytes += 2 * sizeof(long);
Eric Andersencc8ed391999-10-05 16:24:54 +00002462
Erik Andersene49d5ec2000-02-08 19:58:47 +00002463 flush_outbuf();
2464 return OK;
Eric Andersencc8ed391999-10-05 16:24:54 +00002465}
2466
2467
2468/* ===========================================================================
2469 * Read a new buffer from the current input file, perform end-of-line
2470 * translation, and update the crc and input file size.
2471 * IN assertion: size >= 2 (for end-of-line translation)
2472 */
Eric Andersen3073dfb2001-07-02 17:57:32 +00002473static int file_read(char *buf, unsigned size)
Eric Andersencc8ed391999-10-05 16:24:54 +00002474{
Erik Andersene49d5ec2000-02-08 19:58:47 +00002475 unsigned len;
Eric Andersencc8ed391999-10-05 16:24:54 +00002476
Erik Andersene49d5ec2000-02-08 19:58:47 +00002477 Assert(insize == 0, "inbuf not empty");
Eric Andersencc8ed391999-10-05 16:24:54 +00002478
Erik Andersene49d5ec2000-02-08 19:58:47 +00002479 len = read(ifd, buf, size);
2480 if (len == (unsigned) (-1) || len == 0)
2481 return (int) len;
Eric Andersencc8ed391999-10-05 16:24:54 +00002482
Erik Andersene49d5ec2000-02-08 19:58:47 +00002483 crc = updcrc((uch *) buf, len);
2484 isize += (ulg) len;
2485 return (int) len;
Eric Andersencc8ed391999-10-05 16:24:54 +00002486}
Matt Kraai7918e1f2000-11-08 06:52:57 +00002487
2488/* ===========================================================================
2489 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
2490 * (used for the compressed data only)
2491 */
Mike Frysinger4e5936e2005-04-16 04:30:38 +00002492static void flush_outbuf(void)
Matt Kraai7918e1f2000-11-08 06:52:57 +00002493{
2494 if (outcnt == 0)
2495 return;
2496
2497 write_buf(ofd, (char *) outbuf, outcnt);
Matt Kraai7918e1f2000-11-08 06:52:57 +00002498 outcnt = 0;
2499}