1 /* vi: set sw=4 ts=4: */
3 * Gzip implementation for busybox
5 * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly.
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."
12 * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
13 * to support files as well as stdin/stdout, and to generally behave itself wrt
14 * command line handling.
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 * General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
33 #define BB_DECLARE_EXTERN
34 #define bb_need_memory_exhausted
37 /* These defines are very important for BusyBox. Without these,
38 * huge chunks of ram are pre-allocated making the BusyBox bss
39 * size Freaking Huge(tm), which is a bad thing.*/
43 /* I don't like nested includes, but the string and io functions are used
48 #define memzero(s, n) memset ((void *)(s), 0, (n))
51 # define RETSIGTYPE void
56 typedef unsigned char uch;
57 typedef unsigned short ush;
58 typedef unsigned long ulg;
60 /* Return codes from gzip */
65 /* Compression methods (see algorithm.doc) */
70 /* methods 4 to 7 reserved */
73 extern int method; /* compression method */
75 /* To save memory for 16 bit systems, some arrays are overlaid between
76 * the various modules:
77 * deflate: prev+head window d_buf l_buf outbuf
78 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
79 * inflate: window inbuf
80 * unpack: window inbuf prefix_len
81 * unlzh: left+right window c_table inbuf c_len
82 * For compression, input is done in window[]. For decompression, output
83 * is done in window except for unlzw.
88 # define INBUFSIZ 0x2000 /* input buffer size */
90 # define INBUFSIZ 0x8000 /* input buffer size */
93 #define INBUF_EXTRA 64 /* required by unlzw() */
97 # define OUTBUFSIZ 8192 /* output buffer size */
99 # define OUTBUFSIZ 16384 /* output buffer size */
102 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
106 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
108 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
113 # define EXTERN(type, array) extern type * array
114 # define DECLARE(type, array, size) type * array
115 # define ALLOC(type, array, size) { \
116 array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
117 if (array == NULL) error_msg(memory_exhausted); \
119 # define FREE(array) {if (array != NULL) free(array), array=NULL;}
121 # define EXTERN(type, array) extern type array[]
122 # define DECLARE(type, array, size) type array[size]
123 # define ALLOC(type, array, size)
127 EXTERN(uch, inbuf); /* input buffer */
128 EXTERN(uch, outbuf); /* output buffer */
129 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
130 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
131 #define tab_suffix window
133 # define tab_prefix prev /* hash link (see deflate.c) */
134 # define head (prev+WSIZE) /* hash head (see deflate.c) */
135 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
137 # define tab_prefix0 prev
138 # define head tab_prefix1
139 EXTERN(ush, tab_prefix0); /* prefix for even codes */
140 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
143 extern unsigned insize; /* valid bytes in inbuf */
144 extern unsigned inptr; /* index of next byte to be processed in inbuf */
145 extern unsigned outcnt; /* bytes in output buffer */
147 extern long bytes_in; /* number of input bytes */
148 extern long bytes_out; /* number of output bytes */
149 extern long header_bytes; /* number of bytes in gzip header */
151 #define isize bytes_in
152 /* for compatibility with old zip sources (to be cleaned) */
154 extern int ifd; /* input file descriptor */
155 extern int ofd; /* output file descriptor */
156 extern char ifname[]; /* input file name or "stdin" */
157 extern char ofname[]; /* output file name or "stdout" */
158 extern char *progname; /* program name */
160 extern long time_stamp; /* original time stamp (modification time) */
161 extern long ifile_size; /* input file size, -1 for devices (debug only) */
163 typedef int file_t; /* Do not use stdio */
165 #define NO_FILE (-1) /* in memory compression */
168 #define PACK_MAGIC "\037\036" /* Magic header for packed files */
169 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
170 #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
171 #define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */
172 #define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
175 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
176 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
177 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
178 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
179 #define COMMENT 0x10 /* bit 4 set: file comment present */
180 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
181 #define RESERVED 0xC0 /* bit 6,7: reserved */
183 /* internal file attribute */
184 #define UNKNOWN 0xffff
189 # define WSIZE 0x8000 /* window size--must be a power of two, and */
190 #endif /* at least 32K for zip's deflate method */
193 #define MAX_MATCH 258
194 /* The minimum and maximum match lengths */
196 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
197 /* Minimum amount of lookahead, except at the end of the input file.
198 * See deflate.c for comments about the MIN_MATCH+1.
201 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
202 /* In order to simplify the code, particularly on 16 bit machines, match
203 * distances are limited to MAX_DIST instead of WSIZE.
206 extern int decrypt; /* flag to turn on decryption */
207 extern int exit_code; /* program exit code */
208 extern int verbose; /* be verbose (-v) */
209 extern int quiet; /* be quiet (-q) */
210 extern int test; /* check .z file integrity */
211 extern int save_orig_name; /* set if original name must be saved */
213 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
214 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
216 /* put_byte is used for the compressed output, put_ubyte for the
217 * uncompressed output. However unlzw() uses window for its
218 * suffix table instead of its output buffer, so it does not use put_ubyte
219 * (to be cleaned up).
221 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
223 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
226 /* Output a 16 bit value, lsb first */
227 #define put_short(w) \
228 { if (outcnt < OUTBUFSIZ-2) { \
229 outbuf[outcnt++] = (uch) ((w) & 0xff); \
230 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
232 put_byte((uch)((w) & 0xff)); \
233 put_byte((uch)((ush)(w) >> 8)); \
237 /* Output a 32 bit value to the bit stream, lsb first */
238 #define put_long(n) { \
239 put_short((n) & 0xffff); \
240 put_short(((ulg)(n)) >> 16); \
243 #define seekable() 0 /* force sequential output */
244 #define translate_eol 0 /* no option -a yet */
246 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
248 /* Macros for getting two-byte and four-byte header values */
249 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
250 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
252 /* Diagnostic functions */
254 # define Assert(cond,msg) {if(!(cond)) error_msg(msg);}
255 # define Trace(x) fprintf x
256 # define Tracev(x) {if (verbose) fprintf x ;}
257 # define Tracevv(x) {if (verbose>1) fprintf x ;}
258 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
259 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
261 # define Assert(cond,msg)
266 # define Tracecv(c,x)
269 #define WARN(msg) {if (!quiet) fprintf msg ; \
270 if (exit_code == OK) exit_code = WARNING;}
274 extern int zip (int in, int out);
275 extern int file_read (char *buf, unsigned size);
278 extern int unzip (int in, int out);
279 extern int check_zipfile (int in);
282 extern int unpack (int in, int out);
285 extern int unlzh (int in, int out);
288 RETSIGTYPE abort_gzip (void);
291 void lm_init (ush * flags);
295 void ct_init (ush * attr, int *method);
296 int ct_tally (int dist, int lc);
297 ulg flush_block (char *buf, ulg stored_len, int eof);
300 void bi_init (file_t zipfile);
301 void send_bits (int value, int length);
302 unsigned bi_reverse (unsigned value, int length);
303 void bi_windup (void);
304 void copy_block (char *buf, unsigned len, int header);
305 extern int (*read_buf) (char *buf, unsigned size);
308 extern int copy (int in, int out);
309 extern ulg updcrc (uch * s, unsigned n);
310 extern void clear_bufs (void);
311 extern int fill_inbuf (int eof_ok);
312 extern void flush_outbuf (void);
313 extern void flush_window (void);
314 extern void write_buf (int fd, void * buf, unsigned cnt);
315 extern char *strlwr (char *s);
316 extern char *add_envopt (int *argcp, char ***argvp, char *env);
317 extern void read_error_msg (void);
318 extern void write_error_msg (void);
319 extern void display_ratio (long num, long den, FILE * file);
322 extern int inflate (void);
324 /* lzw.h -- define the lzw functions.
325 * Copyright (C) 1992-1993 Jean-loup Gailly.
326 * This is free software; you can redistribute it and/or modify it under the
327 * terms of the GNU General Public License, see the file COPYING.
330 #if !defined(OF) && defined(lint)
337 #define INIT_BITS 9 /* Initial number of bits per code */
339 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
340 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
341 * It's a pity that old uncompress does not check bit 0x20. That makes
342 * extension of the format actually undesirable because old compress
343 * would just crash on the new format instead of giving a meaningful
344 * error message. It does check the number of bits, but it's more
345 * helpful to say "unsupported format, get a new version" than
346 * "can only handle 16 bits".
349 #define BLOCK_MODE 0x80
350 /* Block compression: if table is full and compression rate is dropping,
351 * clear the dictionary.
354 #define LZW_RESERVED 0x60 /* reserved bits */
356 #define CLEAR 256 /* flush the dictionary */
357 #define FIRST (CLEAR+1) /* first free entry */
359 extern int maxbits; /* max bits per code for LZW */
360 extern int block_mode; /* block compress mode -C compatible with 2.0 */
362 /* revision.h -- define the version number
363 * Copyright (C) 1992-1993 Jean-loup Gailly.
364 * This is free software; you can redistribute it and/or modify it under the
365 * terms of the GNU General Public License, see the file COPYING.
368 #define VERSION "1.2.4"
370 #define REVDATE "18 Aug 93"
372 /* This version does not support compression into old compress format: */
377 /* tailor.h -- target dependent definitions
378 * Copyright (C) 1992-1993 Jean-loup Gailly.
379 * This is free software; you can redistribute it and/or modify it under the
380 * terms of the GNU General Public License, see the file COPYING.
383 /* The target dependent definitions should be defined here only.
384 * The target dependent functions should be defined in tailor.c.
388 #if defined(__MSDOS__) && !defined(MSDOS)
392 #if defined(__OS2__) && !defined(OS2)
396 #if defined(OS2) && defined(MSDOS) /* MS C under OS/2 */
402 /* DJGPP version 1.09+ on MS-DOS.
403 * The DJGPP 1.09 stat() function must be upgraded before gzip will
405 * No need for DIRENT, since <unistd.h> defines POSIX_SOURCE which
419 # define HAVE_SYS_UTIME_H
423 # define PATH_SEP2 '\\'
424 # define PATH_SEP3 ':'
425 # define MAX_PATH_LEN 128
426 # define NO_MULTIPLE_DOTS
427 # define MAX_EXT_CHARS 3
428 # define Z_SUFFIX "z"
431 # define STDC_HEADERS
432 # define NO_SIZE_CHECK
433 # define casemap(c) tolow(c) /* Force file names to lower case */
435 # define OS_CODE 0x00
436 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
437 # if !defined(NO_ASM) && !defined(ASMV)
445 # define PATH_SEP2 '\\'
446 # define PATH_SEP3 ':'
447 # define MAX_PATH_LEN 260
449 # define NO_MULTIPLE_DOTS
450 # define MAX_EXT_CHARS 3
451 # define Z_SUFFIX "z"
452 # define casemap(c) tolow(c)
456 # define STDC_HEADERS
458 # define OS_CODE 0x06
459 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
461 # define HAVE_SYS_UTIME_H
468 # define HAVE_SYS_UTIME_H
471 # define EXPAND(argc,argv) \
472 {_response(&argc, &argv); _wildcard(&argc, &argv);}
481 # define EXPAND(argc,argv) \
482 {response_expand(&argc, &argv);}
486 #ifdef WIN32 /* Windows NT */
487 # define HAVE_SYS_UTIME_H
489 # define PATH_SEP2 '\\'
490 # define PATH_SEP3 ':'
491 # define MAX_PATH_LEN 260
494 # define STDC_HEADERS
495 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
499 # define NO_MULTIPLE_DOTS
500 # define MAX_EXT_CHARS 3
501 # define Z_SUFFIX "z"
502 # define casemap(c) tolow(c) /* Force file names to lower case */
504 # define OS_CODE 0x0b
511 /* Turbo C 2.0 does not accept static allocations of large arrays */
512 void *fcalloc(unsigned items, unsigned size);
513 void fcfree(void *ptr);
516 # define fcalloc(nitems,itemsize) halloc((long)(nitems),(itemsize))
517 # define fcfree(ptr) hfree(ptr)
521 # define fcalloc(items,size) calloc((items),(size))
523 # define fcalloc(items,size) malloc((size_t)(items)*(size_t)(size))
525 # define fcfree(ptr) free(ptr)
528 #if defined(VAXC) || defined(VMS)
529 # define PATH_SEP ']'
530 # define PATH_SEP2 ':'
531 # define SUFFIX_SEP ';'
532 # define NO_MULTIPLE_DOTS
533 # define Z_SUFFIX "-gz"
535 # define casemap(c) tolow(c)
536 # define OS_CODE 0x02
537 # define OPTIONS_VAR "GZIP_OPT"
538 # define STDC_HEADERS
540 # define EXPAND(argc,argv) vms_expand_args(&argc,&argv);
542 # define unlink delete
550 # define PATH_SEP2 ':'
551 # define STDC_HEADERS
552 # define OS_CODE 0x01
556 # define HAVE_UNISTD_H
558 # define NO_STDIN_FSTAT
563 # include <fcntl.h> /* for read() and write() */
564 # define direct dirent
565 extern void _expand_args(int *argc, char ***argv);
567 # define EXPAND(argc,argv) _expand_args(&argc,&argv);
568 # undef O_BINARY /* disable useless --ascii option */
572 #if defined(ATARI) || defined(atarist)
573 # ifndef STDC_HEADERS
574 # define STDC_HEADERS
575 # define HAVE_UNISTD_H
579 # define OS_CODE 0x05
581 # define PATH_SEP2 '\\'
582 # define PATH_SEP3 ':'
583 # define MAX_PATH_LEN 128
584 # define NO_MULTIPLE_DOTS
585 # define MAX_EXT_CHARS 3
586 # define Z_SUFFIX "z"
588 # define casemap(c) tolow(c) /* Force file names to lower case */
594 # define PATH_SEP ':'
597 # define NO_STDIN_FSTAT
600 # define chmod(file, mode) (0)
601 # define OPEN(name, flags, mode) open(name, flags)
602 # define OS_CODE 0x07
604 # define isatty(fd) ((fd) <= 2)
608 #ifdef __50SERIES /* Prime/PRIMOS */
609 # define PATH_SEP '>'
610 # define STDC_HEADERS
615 # define NO_STDIN_FSTAT
616 # define NO_SIZE_CHECK
619 # define casemap(c) tolow(c) /* Force file names to lower case */
620 # define put_char(c) put_byte((c) & 0x7F)
621 # define get_char(c) ascii2pascii(get_byte())
622 # define OS_CODE 0x0F /* temporary, subject to change */
624 # undef SIGTERM /* We don't want a signal handler for SIGTERM */
628 #if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */
629 # define NOMEMCPY /* problem with overlapping copies */
633 # define OS_CODE 0x0a
637 # define NO_ST_INO /* don't rely on inode numbers */
641 /* Common defaults */
644 # define OS_CODE 0x03 /* assume Unix */
648 # define PATH_SEP '/'
652 # define casemap(c) (c)
656 # define OPTIONS_VAR "GZIP"
660 # define Z_SUFFIX ".gz"
664 # define MAX_SUFFIX MAX_EXT_CHARS
666 # define MAX_SUFFIX 30
669 #ifndef MAKE_LEGAL_NAME
670 # ifdef NO_MULTIPLE_DOTS
671 # define MAKE_LEGAL_NAME(name) make_simple_name(name)
673 # define MAKE_LEGAL_NAME(name)
679 /* keep at least MIN_PART chars between dots in a file name. */
683 # define EXPAND(argc,argv)
690 #ifndef SET_BINARY_MODE
691 # define SET_BINARY_MODE(fd)
695 # define OPEN(name, flags, mode) open(name, flags, mode)
699 # define get_char() get_byte()
703 # define put_char(c) put_byte(c)
705 /* bits.c -- output variable-length bit strings
706 * Copyright (C) 1992-1993 Jean-loup Gailly
707 * This is free software; you can redistribute it and/or modify it under the
708 * terms of the GNU General Public License, see the file COPYING.
715 * Output variable-length bit strings. Compression can be done
716 * to a file or to memory. (The latter is not supported in this version.)
720 * The PKZIP "deflate" file format interprets compressed file data
721 * as a sequence of bits. Multi-bit strings in the file may cross
722 * byte boundaries without restriction.
724 * The first bit of each byte is the low-order bit.
726 * The routines in this file allow a variable-length bit value to
727 * be output right-to-left (useful for literal values). For
728 * left-to-right output (useful for code strings from the tree routines),
729 * the bits must have been reversed first with bi_reverse().
731 * For in-memory compression, the compressed bit stream goes directly
732 * into the requested output buffer. The input data is read in blocks
733 * by the mem_read() function. The buffer is limited to 64K on 16 bit
738 * void bi_init (FILE *zipfile)
739 * Initialize the bit string routines.
741 * void send_bits (int value, int length)
742 * Write out a bit string, taking the source bits right to
745 * int bi_reverse (int value, int length)
746 * Reverse the bits of a bit string, taking the source bits left to
747 * right and emitting them right to left.
749 * void bi_windup (void)
750 * Write out any remaining bits in an incomplete byte.
752 * void copy_block(char *buf, unsigned len, int header)
753 * Copy a stored block to the zip file, storing first the length and
754 * its one's complement if requested.
762 /* ===========================================================================
763 * Local data used by the "bit string" routines.
766 local file_t zfile; /* output gzip file */
768 local unsigned short bi_buf;
770 /* Output buffer. bits are inserted starting at the bottom (least significant
774 #define Buf_size (8 * 2*sizeof(char))
775 /* Number of bits used within bi_buf. (bi_buf might be implemented on
776 * more than 16 bits on some systems.)
781 /* Number of valid bits in bi_buf. All bits above the last valid bit
785 int (*read_buf) (char *buf, unsigned size);
787 /* Current input function. Set to mem_read for in-memory compression */
790 ulg bits_sent; /* bit length of the compressed data */
793 /* ===========================================================================
794 * Initialize the bit string routines.
796 void bi_init(zipfile)
797 file_t zipfile; /* output zip file, NO_FILE for in-memory compression */
806 /* Set the defaults for file compression. They are set by memcompress
807 * for in-memory compression.
809 if (zfile != NO_FILE) {
810 read_buf = file_read;
814 /* ===========================================================================
815 * Send a value on a given number of bits.
816 * IN assertion: length <= 16 and value fits in length bits.
818 void send_bits(value, length)
819 int value; /* value to send */
820 int length; /* number of bits */
823 Tracev((stderr, " l %2d v %4x ", length, value));
824 Assert(length > 0 && length <= 15, "invalid length");
825 bits_sent += (ulg) length;
827 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
828 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
829 * unused bits in value.
831 if (bi_valid > (int) Buf_size - length) {
832 bi_buf |= (value << bi_valid);
834 bi_buf = (ush) value >> (Buf_size - bi_valid);
835 bi_valid += length - Buf_size;
837 bi_buf |= value << bi_valid;
842 /* ===========================================================================
843 * Reverse the first len bits of a code, using straightforward code (a faster
844 * method would use a table)
845 * IN assertion: 1 <= len <= 15
847 unsigned bi_reverse(code, len)
848 unsigned code; /* the value to invert */
849 int len; /* its bit length */
851 register unsigned res = 0;
855 code >>= 1, res <<= 1;
860 /* ===========================================================================
861 * Write out any remaining bits in an incomplete byte.
867 } else if (bi_valid > 0) {
873 bits_sent = (bits_sent + 7) & ~7;
877 /* ===========================================================================
878 * Copy a stored block to the zip file, storing first the length and its
879 * one's complement if requested.
881 void copy_block(buf, len, header)
882 char *buf; /* the input data */
883 unsigned len; /* its length */
884 int header; /* true if block header must be written */
886 bi_windup(); /* align on byte boundary */
889 put_short((ush) len);
890 put_short((ush) ~ len);
896 bits_sent += (ulg) len << 3;
909 /* deflate.c -- compress data using the deflation algorithm
910 * Copyright (C) 1992-1993 Jean-loup Gailly
911 * This is free software; you can redistribute it and/or modify it under the
912 * terms of the GNU General Public License, see the file COPYING.
918 * Identify new text as repetitions of old text within a fixed-
919 * length sliding window trailing behind the new text.
923 * The "deflation" process depends on being able to identify portions
924 * of the input text which are identical to earlier input (within a
925 * sliding window trailing behind the input currently being processed).
927 * The most straightforward technique turns out to be the fastest for
928 * most input files: try all possible matches and select the longest.
929 * The key feature of this algorithm is that insertions into the string
930 * dictionary are very simple and thus fast, and deletions are avoided
931 * completely. Insertions are performed at each input character, whereas
932 * string matches are performed only when the previous match ends. So it
933 * is preferable to spend more time in matches to allow very fast string
934 * insertions and avoid deletions. The matching algorithm for small
935 * strings is inspired from that of Rabin & Karp. A brute force approach
936 * is used to find longer strings when a small match has been found.
937 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
938 * (by Leonid Broukhis).
939 * A previous version of this file used a more sophisticated algorithm
940 * (by Fiala and Greene) which is guaranteed to run in linear amortized
941 * time, but has a larger average cost, uses more memory and is patented.
942 * However the F&G algorithm may be faster for some highly redundant
943 * files if the parameter max_chain_length (described below) is too large.
947 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
948 * I found it in 'freeze' written by Leonid Broukhis.
949 * Thanks to many info-zippers for bug reports and testing.
953 * APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
955 * A description of the Rabin and Karp algorithm is given in the book
956 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
958 * Fiala,E.R., and Greene,D.H.
959 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
963 * void lm_init (int pack_level, ush *flags)
964 * Initialize the "longest match" routines for a new file
967 * Processes a new input file and return its compressed length. Sets
968 * the compressed length, crc, deflate flags and internal file
974 /* ===========================================================================
975 * Configuration parameters
978 /* Compile with MEDIUM_MEM to reduce the memory requirements or
979 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
980 * entire input file can be held in memory (not possible on 16 bit systems).
981 * Warning: defining these symbols affects HASH_BITS (see below) and thus
982 * affects the compression ratio. The compressed output
983 * is still correct, and might even be smaller in some cases.
987 # define HASH_BITS 13 /* Number of bits used to hash strings */
990 # define HASH_BITS 14
993 # define HASH_BITS 15
994 /* For portability to 16 bit machines, do not use values above 15. */
997 /* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
998 * window with tab_suffix. Check that we can do this:
1000 #if (WSIZE<<1) > (1<<BITS)
1001 error:cannot overlay window with tab_suffix and prev with tab_prefix0
1003 #if HASH_BITS > BITS-1
1004 error:cannot overlay head with tab_prefix1
1006 #define HASH_SIZE (unsigned)(1<<HASH_BITS)
1007 #define HASH_MASK (HASH_SIZE-1)
1008 #define WMASK (WSIZE-1)
1009 /* HASH_SIZE and WSIZE must be powers of two */
1011 /* Tail of hash chains */
1014 /* speed options for the general purpose bit flag */
1016 # define TOO_FAR 4096
1018 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
1019 /* ===========================================================================
1020 * Local data used by the "longest match" routines.
1023 typedef unsigned IPos;
1025 /* A Pos is an index in the character window. We use short instead of int to
1026 * save space in the various tables. IPos is used only for parameter passing.
1029 /* DECLARE(uch, window, 2L*WSIZE); */
1030 /* Sliding window. Input bytes are read into the second half of the window,
1031 * and move to the first half later to keep a dictionary of at least WSIZE
1032 * bytes. With this organization, matches are limited to a distance of
1033 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
1034 * performed with a length multiple of the block size. Also, it limits
1035 * the window size to 64K, which is quite useful on MSDOS.
1036 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
1037 * be less efficient).
1040 /* DECLARE(Pos, prev, WSIZE); */
1041 /* Link to older string with same hash index. To limit the size of this
1042 * array to 64K, this link is maintained only for the last 32K strings.
1043 * An index in this array is thus a window index modulo 32K.
1046 /* DECLARE(Pos, head, 1<<HASH_BITS); */
1047 /* Heads of the hash chains or NIL. */
1049 ulg window_size = (ulg) 2 * WSIZE;
1051 /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
1052 * input file length plus MIN_LOOKAHEAD.
1057 /* window position at the beginning of the current output block. Gets
1058 * negative when the window is moved backwards.
1061 local unsigned ins_h; /* hash index of string to be inserted */
1063 #define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
1064 /* Number of bits by which ins_h and del_h must be shifted at each
1065 * input step. It must be such that after MIN_MATCH steps, the oldest
1066 * byte no longer takes part in the hash key, that is:
1067 * H_SHIFT * MIN_MATCH >= HASH_BITS
1070 unsigned int near prev_length;
1072 /* Length of the best match at previous step. Matches not greater than this
1073 * are discarded. This is used in the lazy match evaluation.
1076 unsigned near strstart; /* start of string to insert */
1077 unsigned near match_start; /* start of matching string */
1078 local int eofile; /* flag set at end of input file */
1079 local unsigned lookahead; /* number of valid bytes ahead in window */
1081 unsigned near max_chain_length;
1083 /* To speed up deflation, hash chains are never searched beyond this length.
1084 * A higher limit improves compression ratio but degrades the speed.
1087 local unsigned int max_lazy_match;
1089 /* Attempt to find a better match only when the current match is strictly
1090 * smaller than this value. This mechanism is used only for compression
1093 #define max_insert_length max_lazy_match
1094 /* Insert new strings in the hash table only if the match length
1095 * is not greater than this length. This saves time but degrades compression.
1096 * max_insert_length is used only for compression levels <= 3.
1099 unsigned near good_match;
1101 /* Use a faster search when the previous match is longer than this */
1104 /* Values for max_lazy_match, good_match and max_chain_length, depending on
1105 * the desired pack level (0..9). The values given below have been tuned to
1106 * exclude worst case performance for pathological files. Better values may be
1107 * found for specific files.
1110 typedef struct config {
1111 ush good_length; /* reduce lazy search above this match length */
1112 ush max_lazy; /* do not perform lazy search above this match length */
1113 ush nice_length; /* quit search above this match length */
1118 # define nice_match MAX_MATCH
1120 int near nice_match; /* Stop searching when current match exceeds this */
1123 local config configuration_table =
1124 /* 9 */ { 32, 258, 258, 4096 };
1125 /* maximum compression */
1127 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
1128 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
1133 /* result of memcmp for equal strings */
1135 /* ===========================================================================
1136 * Prototypes for local functions.
1138 local void fill_window (void);
1140 int longest_match (IPos cur_match);
1143 void match_init (void); /* asm code initialization */
1147 local void check_match (IPos start, IPos match, int length);
1150 /* ===========================================================================
1151 * Update a hash value with the given input byte
1152 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
1153 * input characters, so that a running hash key can be computed from the
1154 * previous key instead of complete recalculation each time.
1156 #define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
1158 /* ===========================================================================
1159 * Insert string s in the dictionary and set match_head to the previous head
1160 * of the hash chain (the most recent string with same hash key). Return
1161 * the previous length of the hash chain.
1162 * IN assertion: all calls to to INSERT_STRING are made with consecutive
1163 * input characters and the first MIN_MATCH bytes of s are valid
1164 * (except for the last MIN_MATCH-1 bytes of the input file).
1166 #define INSERT_STRING(s, match_head) \
1167 (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
1168 prev[(s) & WMASK] = match_head = head[ins_h], \
1171 /* ===========================================================================
1172 * Initialize the "longest match" routines for a new file
1175 ush *flags; /* general purpose bit flag */
1177 register unsigned j;
1179 /* Initialize the hash table. */
1180 #if defined(MAXSEG_64K) && HASH_BITS == 15
1181 for (j = 0; j < HASH_SIZE; j++)
1184 memzero((char *) head, HASH_SIZE * sizeof(*head));
1186 /* prev will be initialized on the fly */
1188 /* Set the default configuration parameters:
1190 max_lazy_match = configuration_table.max_lazy;
1191 good_match = configuration_table.good_length;
1193 nice_match = configuration_table.nice_length;
1195 max_chain_length = configuration_table.max_chain;
1197 /* ??? reduce max_chain_length for binary files */
1202 match_init(); /* initialize the asm code */
1205 lookahead = read_buf((char *) window,
1206 sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
1208 if (lookahead == 0 || lookahead == (unsigned) EOF) {
1209 eofile = 1, lookahead = 0;
1213 /* Make sure that we always have enough lookahead. This is important
1214 * if input comes from a device such as a tty.
1216 while (lookahead < MIN_LOOKAHEAD && !eofile)
1220 for (j = 0; j < MIN_MATCH - 1; j++)
1221 UPDATE_HASH(ins_h, window[j]);
1222 /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
1223 * not important since only literal bytes will be emitted.
1227 /* ===========================================================================
1228 * Set match_start to the longest match starting at the given string and
1229 * return its length. Matches shorter or equal to prev_length are discarded,
1230 * in which case the result is equal to prev_length and match_start is
1232 * IN assertions: cur_match is the head of the hash chain for the current
1233 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1236 /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
1237 * match.s. The code is functionally equivalent, so you can use the C version
1240 int longest_match(cur_match)
1241 IPos cur_match; /* current match */
1243 unsigned chain_length = max_chain_length; /* max hash chain length */
1244 register uch *scan = window + strstart; /* current string */
1245 register uch *match; /* matched string */
1246 register int len; /* length of current match */
1247 int best_len = prev_length; /* best match length so far */
1250 strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL;
1251 /* Stop when cur_match becomes <= limit. To simplify the code,
1252 * we prevent matches with the string of window index 0.
1255 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1256 * It is easy to get rid of this optimization if necessary.
1258 #if HASH_BITS < 8 || MAX_MATCH != 258
1259 error:Code too clever
1262 /* Compare two bytes at a time. Note: this is not always beneficial.
1263 * Try with and without -DUNALIGNED_OK to check.
1265 register uch *strend = window + strstart + MAX_MATCH - 1;
1266 register ush scan_start = *(ush *) scan;
1267 register ush scan_end = *(ush *) (scan + best_len - 1);
1269 register uch *strend = window + strstart + MAX_MATCH;
1270 register uch scan_end1 = scan[best_len - 1];
1271 register uch scan_end = scan[best_len];
1274 /* Do not waste too much time if we already have a good match: */
1275 if (prev_length >= good_match) {
1278 Assert(strstart <= window_size - MIN_LOOKAHEAD,
1279 "insufficient lookahead");
1282 Assert(cur_match < strstart, "no future");
1283 match = window + cur_match;
1285 /* Skip to next match if the match length cannot increase
1286 * or if the match length is less than 2:
1288 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1289 /* This code assumes sizeof(unsigned short) == 2. Do not use
1290 * UNALIGNED_OK if your compiler uses a different size.
1292 if (*(ush *) (match + best_len - 1) != scan_end ||
1293 *(ush *) match != scan_start)
1296 /* It is not necessary to compare scan[2] and match[2] since they are
1297 * always equal when the other bytes match, given that the hash keys
1298 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1299 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1300 * lookahead only every 4th comparison; the 128th check will be made
1301 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1302 * necessary to put more guard bytes at the end of the window, or
1303 * to check more often for insufficient lookahead.
1307 } while (*(ush *) (scan += 2) == *(ush *) (match += 2) &&
1308 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1309 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1310 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1312 /* The funny "do {}" generates better code on most compilers */
1314 /* Here, scan <= window+strstart+257 */
1315 Assert(scan <= window + (unsigned) (window_size - 1), "wild scan");
1316 if (*scan == *match)
1319 len = (MAX_MATCH - 1) - (int) (strend - scan);
1320 scan = strend - (MAX_MATCH - 1);
1322 #else /* UNALIGNED_OK */
1324 if (match[best_len] != scan_end ||
1325 match[best_len - 1] != scan_end1 ||
1326 *match != *scan || *++match != scan[1])
1329 /* The check at best_len-1 can be removed because it will be made
1330 * again later. (This heuristic is not always a win.)
1331 * It is not necessary to compare scan[2] and match[2] since they
1332 * are always equal when the other bytes match, given that
1333 * the hash keys are equal and that HASH_BITS >= 8.
1337 /* We check for insufficient lookahead only every 8th comparison;
1338 * the 256th check will be made at strstart+258.
1341 } while (*++scan == *++match && *++scan == *++match &&
1342 *++scan == *++match && *++scan == *++match &&
1343 *++scan == *++match && *++scan == *++match &&
1344 *++scan == *++match && *++scan == *++match &&
1347 len = MAX_MATCH - (int) (strend - scan);
1348 scan = strend - MAX_MATCH;
1350 #endif /* UNALIGNED_OK */
1352 if (len > best_len) {
1353 match_start = cur_match;
1355 if (len >= nice_match)
1358 scan_end = *(ush *) (scan + best_len - 1);
1360 scan_end1 = scan[best_len - 1];
1361 scan_end = scan[best_len];
1364 } while ((cur_match = prev[cur_match & WMASK]) > limit
1365 && --chain_length != 0);
1372 /* ===========================================================================
1373 * Check that the match at match_start is indeed a match.
1375 local void check_match(start, match, length)
1379 /* check that the match is indeed a match */
1380 if (memcmp((char *) window + match,
1381 (char *) window + start, length) != EQUAL) {
1383 " start %d, match %d, length %d\n", start, match, length);
1384 error_msg("invalid match\n");
1387 fprintf(stderr, "\\[%d,%d]", start - match, length);
1389 putc(window[start++], stderr);
1390 } while (--length != 0);
1394 # define check_match(start, match, length)
1397 /* ===========================================================================
1398 * Fill the window when the lookahead becomes insufficient.
1399 * Updates strstart and lookahead, and sets eofile if end of input file.
1400 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
1401 * OUT assertions: at least one byte has been read, or eofile is set;
1402 * file reads are performed for at least two bytes (required for the
1403 * translate_eol option).
1405 local void fill_window()
1407 register unsigned n, m;
1410 (unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
1411 /* Amount of free space at the end of the window. */
1413 /* If the window is almost full and there is insufficient lookahead,
1414 * move the upper half to the lower one to make room in the upper half.
1416 if (more == (unsigned) EOF) {
1417 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1418 * and lookahead == 1 (input done one byte at time)
1421 } else if (strstart >= WSIZE + MAX_DIST) {
1422 /* By the IN assertion, the window is not empty so we can't confuse
1423 * more == 0 with more == 64K on a 16 bit machine.
1425 Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM");
1427 memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE);
1428 match_start -= WSIZE;
1429 strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
1431 block_start -= (long) WSIZE;
1433 for (n = 0; n < HASH_SIZE; n++) {
1435 head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
1437 for (n = 0; n < WSIZE; n++) {
1439 prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
1440 /* If n is not on any hash chain, prev[n] is garbage but
1441 * its value will never be used.
1446 /* At this point, more >= 2 */
1448 n = read_buf((char *) window + strstart + lookahead, more);
1449 if (n == 0 || n == (unsigned) EOF) {
1457 /* ===========================================================================
1458 * Flush the current block, with given end-of-file flag.
1459 * IN assertion: strstart is set to the end of the current match.
1461 #define FLUSH_BLOCK(eof) \
1462 flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
1463 (char*)NULL, (long)strstart - block_start, (eof))
1465 /* ===========================================================================
1466 * Same as above, but achieves better compression. We use a lazy
1467 * evaluation for matches: a match is finally adopted only if there is
1468 * no better match at the next window position.
1472 IPos hash_head; /* head of hash chain */
1473 IPos prev_match; /* previous match */
1474 int flush; /* set if current block must be flushed */
1475 int match_available = 0; /* set if previous match exists */
1476 register unsigned match_length = MIN_MATCH - 1; /* length of best match */
1479 extern long isize; /* byte length of input file, for debug only */
1482 /* Process the input block. */
1483 while (lookahead != 0) {
1484 /* Insert the string window[strstart .. strstart+2] in the
1485 * dictionary, and set hash_head to the head of the hash chain:
1487 INSERT_STRING(strstart, hash_head);
1489 /* Find the longest match, discarding those <= prev_length.
1491 prev_length = match_length, prev_match = match_start;
1492 match_length = MIN_MATCH - 1;
1494 if (hash_head != NIL && prev_length < max_lazy_match &&
1495 strstart - hash_head <= MAX_DIST) {
1496 /* To simplify the code, we prevent matches with the string
1497 * of window index 0 (in particular we have to avoid a match
1498 * of the string with itself at the start of the input file).
1500 match_length = longest_match(hash_head);
1501 /* longest_match() sets match_start */
1502 if (match_length > lookahead)
1503 match_length = lookahead;
1505 /* Ignore a length 3 match if it is too distant: */
1506 if (match_length == MIN_MATCH
1507 && strstart - match_start > TOO_FAR) {
1508 /* If prev_match is also MIN_MATCH, match_start is garbage
1509 * but we will ignore the current match anyway.
1514 /* If there was a match at the previous step and the current
1515 * match is not better, output the previous match:
1517 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
1519 check_match(strstart - 1, prev_match, prev_length);
1522 ct_tally(strstart - 1 - prev_match,
1523 prev_length - MIN_MATCH);
1525 /* Insert in hash table all strings up to the end of the match.
1526 * strstart-1 and strstart are already inserted.
1528 lookahead -= prev_length - 1;
1532 INSERT_STRING(strstart, hash_head);
1533 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1534 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1535 * these bytes are garbage, but it does not matter since the
1536 * next lookahead bytes will always be emitted as literals.
1538 } while (--prev_length != 0);
1539 match_available = 0;
1540 match_length = MIN_MATCH - 1;
1543 FLUSH_BLOCK(0), block_start = strstart;
1545 } else if (match_available) {
1546 /* If there was no match at the previous position, output a
1547 * single literal. If there was a match but the current match
1548 * is longer, truncate the previous match to a single literal.
1550 Tracevv((stderr, "%c", window[strstart - 1]));
1551 if (ct_tally(0, window[strstart - 1])) {
1552 FLUSH_BLOCK(0), block_start = strstart;
1557 /* There is no previous match to compare with, wait for
1558 * the next step to decide.
1560 match_available = 1;
1564 Assert(strstart <= isize && lookahead <= isize, "a bit too far");
1566 /* Make sure that we always have enough lookahead, except
1567 * at the end of the input file. We need MAX_MATCH bytes
1568 * for the next match, plus MIN_MATCH bytes to insert the
1569 * string following the next match.
1571 while (lookahead < MIN_LOOKAHEAD && !eofile)
1574 if (match_available)
1575 ct_tally(0, window[strstart - 1]);
1577 return FLUSH_BLOCK(1); /* eof */
1580 /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1581 * Copyright (C) 1992-1993 Jean-loup Gailly
1582 * The unzip code was written and put in the public domain by Mark Adler.
1583 * Portions of the lzw code are derived from the public domain 'compress'
1584 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1585 * Ken Turkowski, Dave Mack and Peter Jannesen.
1587 * See the license_msg below and the file COPYING for the software license.
1588 * See the file algorithm.doc for the compression algorithms and file formats.
1591 /* Compress files with zip algorithm and 'compress' interface.
1592 * See usage() and help() functions below for all options.
1594 * file.gz: compressed file with same mode, owner, and utimes
1595 * or stdout with -c option or if stdin used as input.
1596 * If the output file name had to be truncated, the original name is kept
1597 * in the compressed file.
1598 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
1600 * Using gz on MSDOS would create too many file name conflicts. For
1601 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
1602 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
1603 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
1604 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
1606 * For the meaning of all compilation flags, see comments in Makefile.in.
1610 #include <sys/types.h>
1617 # include <sys/time.h>
1626 #ifdef HAVE_UNISTD_H
1627 # include <unistd.h>
1630 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
1631 # include <stdlib.h>
1637 # include <dirent.h>
1638 typedef struct dirent dir_type;
1640 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
1641 # define DIR_OPT "DIRENT"
1643 # define NLENGTH(dirent) ((dirent)->d_namlen)
1645 # include <sys/dir.h>
1646 typedef struct direct dir_type;
1648 # define DIR_OPT "SYSDIR"
1651 # include <sys/ndir.h>
1652 typedef struct direct dir_type;
1654 # define DIR_OPT "SYSNDIR"
1658 typedef struct direct dir_type;
1660 # define DIR_OPT "NDIR"
1663 # define DIR_OPT "NO_DIR"
1672 # define TIME_OPT "UTIME"
1674 # ifdef HAVE_SYS_UTIME_H
1675 # include <sys/utime.h>
1676 # define TIME_OPT "SYS_UTIME"
1683 # define TIME_OPT ""
1687 # define TIME_OPT "NO_UTIME"
1690 #if !defined(S_ISDIR) && defined(S_IFDIR)
1691 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
1693 #if !defined(S_ISREG) && defined(S_IFREG)
1694 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
1697 typedef RETSIGTYPE(*sig_type) (int);
1700 # define O_BINARY 0 /* creation mode for open() */
1704 /* Pure BSD system? */
1705 # include <sys/file.h>
1707 # define O_CREAT FCREAT
1710 # define O_EXCL FEXCL
1715 # define S_IRUSR 0400
1718 # define S_IWUSR 0200
1720 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
1722 #ifndef MAX_PATH_LEN
1723 # define MAX_PATH_LEN 1024 /* max pathname length */
1732 off_t lseek (int fd, off_t offset, int whence);
1735 /* Separator for file name parts (see shorten_name()) */
1736 #ifdef NO_MULTIPLE_DOTS
1737 # define PART_SEP "-"
1739 # define PART_SEP "."
1742 /* global buffers */
1744 DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1745 DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1746 DECLARE(ush, d_buf, DIST_BUFSIZE);
1747 DECLARE(uch, window, 2L * WSIZE);
1749 DECLARE(ush, tab_prefix, 1L << BITS);
1751 DECLARE(ush, tab_prefix0, 1L << (BITS - 1));
1752 DECLARE(ush, tab_prefix1, 1L << (BITS - 1));
1755 /* local variables */
1757 static int foreground; /* set if program run in foreground */
1758 static int method = DEFLATED; /* compression method */
1759 static int exit_code = OK; /* program exit code */
1760 static int part_nb; /* number of parts in .gz file */
1761 static long time_stamp; /* original time stamp (modification time) */
1762 static long ifile_size; /* input file size, -1 for devices (debug only) */
1763 static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
1764 static int z_len; /* strlen(z_suffix) */
1766 static long bytes_in; /* number of input bytes */
1767 static long bytes_out; /* number of output bytes */
1768 static char ifname[MAX_PATH_LEN]; /* input file name */
1769 static char ofname[MAX_PATH_LEN]; /* output file name */
1770 static int ifd; /* input file descriptor */
1771 static int ofd; /* output file descriptor */
1772 static unsigned insize; /* valid bytes in inbuf */
1773 static unsigned outcnt; /* bytes in output buffer */
1775 /* local functions */
1777 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
1779 /* ======================================================================== */
1780 // int main (argc, argv)
1783 int gzip_main(int argc, char **argv)
1788 struct stat statBuf;
1794 /* Parse any options */
1795 while (--argc > 0 && **(++argv) == '-') {
1796 if (*((*argv) + 1) == '\0') {
1799 while (*(++(*argv))) {
1807 /* Ignore 1-9 (compression level) options */
1808 case '1': case '2': case '3': case '4': case '5':
1809 case '6': case '7': case '8': case '9':
1821 if (isatty(fileno(stdin)) && fromstdin==1 && force==0)
1822 error_msg_and_die( "data not read from terminal. Use -f to force it.\n");
1823 if (isatty(fileno(stdout)) && tostdout==1 && force==0)
1824 error_msg_and_die( "data not written to terminal. Use -f to force it.\n");
1826 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1828 (void) signal(SIGINT, (sig_type) abort_gzip);
1831 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
1832 (void) signal(SIGTERM, (sig_type) abort_gzip);
1836 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
1837 (void) signal(SIGHUP, (sig_type) abort_gzip);
1841 strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
1842 z_len = strlen(z_suffix);
1844 /* Allocate all global buffers (for DYN_ALLOC option) */
1845 ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1846 ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1847 ALLOC(ush, d_buf, DIST_BUFSIZE);
1848 ALLOC(uch, window, 2L * WSIZE);
1850 ALLOC(ush, tab_prefix, 1L << BITS);
1852 ALLOC(ush, tab_prefix0, 1L << (BITS - 1));
1853 ALLOC(ush, tab_prefix1, 1L << (BITS - 1));
1856 if (fromstdin == 1) {
1857 strcpy(ofname, "stdin");
1859 inFileNum = fileno(stdin);
1860 time_stamp = 0; /* time unknown by default */
1861 ifile_size = -1L; /* convention for unknown size */
1863 /* Open up the input file */
1866 strncpy(ifname, *argv, MAX_PATH_LEN);
1868 /* Open input fille */
1869 inFileNum = open(ifname, O_RDONLY);
1870 if (inFileNum < 0) {
1874 /* Get the time stamp on the input file. */
1875 result = stat(ifname, &statBuf);
1880 time_stamp = statBuf.st_ctime;
1881 ifile_size = statBuf.st_size;
1885 if (tostdout == 1) {
1886 /* And get to work */
1887 strcpy(ofname, "stdout");
1888 outFileNum = fileno(stdout);
1889 SET_BINARY_MODE(fileno(stdout));
1891 clear_bufs(); /* clear input and output buffers */
1894 /* Actually do the compression/decompression. */
1895 zip(inFileNum, outFileNum);
1899 /* And get to work */
1900 strncpy(ofname, ifname, MAX_PATH_LEN - 4);
1901 strcat(ofname, ".gz");
1904 /* Open output fille */
1905 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
1906 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
1908 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL);
1910 if (outFileNum < 0) {
1914 SET_BINARY_MODE(outFileNum);
1915 /* Set permissions on the file */
1916 fchmod(outFileNum, statBuf.st_mode);
1918 clear_bufs(); /* clear input and output buffers */
1921 /* Actually do the compression/decompression. */
1922 result = zip(inFileNum, outFileNum);
1925 /* Delete the original file */
1927 delFileName = ifname;
1929 delFileName = ofname;
1931 if (unlink(delFileName) < 0) {
1932 perror(delFileName);
1940 /* trees.c -- output deflated data using Huffman coding
1941 * Copyright (C) 1992-1993 Jean-loup Gailly
1942 * This is free software; you can redistribute it and/or modify it under the
1943 * terms of the GNU General Public License, see the file COPYING.
1949 * Encode various sets of source values using variable-length
1950 * binary code trees.
1954 * The PKZIP "deflation" process uses several Huffman trees. The more
1955 * common source values are represented by shorter bit sequences.
1957 * Each code tree is stored in the ZIP file in a compressed form
1958 * which is itself a Huffman encoding of the lengths of
1959 * all the code strings (in ascending order by source values).
1960 * The actual code strings are reconstructed from the lengths in
1961 * the UNZIP process, as described in the "application note"
1962 * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1967 * Data Compression: Techniques and Applications, pp. 53-55.
1968 * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
1971 * Data Compression: Methods and Theory, pp. 49-50.
1972 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1976 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1980 * void ct_init (ush *attr, int *methodp)
1981 * Allocate the match buffer, initialize the various tables and save
1982 * the location of the internal file attribute (ascii/binary) and
1983 * method (DEFLATE/STORE)
1985 * void ct_tally (int dist, int lc);
1986 * Save the match info and tally the frequency counts.
1988 * long flush_block (char *buf, ulg stored_len, int eof)
1989 * Determine the best encoding for the current block: dynamic trees,
1990 * static trees or store, and output the encoded block to the zip
1991 * file. Returns the total compressed length for the file so far.
1997 /* ===========================================================================
2002 /* All codes must not exceed MAX_BITS bits */
2004 #define MAX_BL_BITS 7
2005 /* Bit length codes must not exceed MAX_BL_BITS bits */
2007 #define LENGTH_CODES 29
2008 /* number of length codes, not counting the special END_BLOCK code */
2010 #define LITERALS 256
2011 /* number of literal bytes 0..255 */
2013 #define END_BLOCK 256
2014 /* end of block literal code */
2016 #define L_CODES (LITERALS+1+LENGTH_CODES)
2017 /* number of Literal or Length codes, including the END_BLOCK code */
2020 /* number of distance codes */
2023 /* number of codes used to transfer the bit lengths */
2026 local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2027 = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
2028 4, 4, 5, 5, 5, 5, 0 };
2030 local int near extra_dbits[D_CODES] /* extra bits for each distance code */
2031 = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
2032 10, 10, 11, 11, 12, 12, 13, 13 };
2034 local int near extra_blbits[BL_CODES] /* extra bits for each bit length code */
2035 = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
2037 #define STORED_BLOCK 0
2038 #define STATIC_TREES 1
2040 /* The three kinds of block type */
2044 # define LIT_BUFSIZE 0x2000
2047 # define LIT_BUFSIZE 0x4000
2049 # define LIT_BUFSIZE 0x8000
2053 #ifndef DIST_BUFSIZE
2054 # define DIST_BUFSIZE LIT_BUFSIZE
2056 /* Sizes of match buffers for literals/lengths and distances. There are
2057 * 4 reasons for limiting LIT_BUFSIZE to 64K:
2058 * - frequencies can be kept in 16 bit counters
2059 * - if compression is not successful for the first block, all input data is
2060 * still in the window so we can still emit a stored block even when input
2061 * comes from standard input. (This can also be done for all blocks if
2062 * LIT_BUFSIZE is not greater than 32K.)
2063 * - if compression is not successful for a file smaller than 64K, we can
2064 * even emit a stored file instead of a stored block (saving 5 bytes).
2065 * - creating new Huffman trees less frequently may not provide fast
2066 * adaptation to changes in the input data statistics. (Take for
2067 * example a binary file with poorly compressible code followed by
2068 * a highly compressible string table.) Smaller buffer sizes give
2069 * fast adaptation but have of course the overhead of transmitting trees
2071 * - I can't count above 4
2072 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
2073 * memory at the expense of compression). Some optimizations would be possible
2074 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
2076 #if LIT_BUFSIZE > INBUFSIZ
2077 error cannot overlay l_buf and inbuf
2080 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2081 #define REPZ_3_10 17
2082 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2083 #define REPZ_11_138 18
2084 /* repeat a zero length 11-138 times (7 bits of repeat count) *//* ===========================================================================
2086 *//* Data structure describing a single value and its code string. */ typedef struct ct_data {
2088 ush freq; /* frequency count */
2089 ush code; /* bit string */
2092 ush dad; /* father node in Huffman tree */
2093 ush len; /* length of bit string */
2097 #define Freq fc.freq
2098 #define Code fc.code
2102 #define HEAP_SIZE (2*L_CODES+1)
2103 /* maximum heap size */
2105 local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */
2106 local ct_data near dyn_dtree[2 * D_CODES + 1]; /* distance tree */
2108 local ct_data near static_ltree[L_CODES + 2];
2110 /* The static literal tree. Since the bit lengths are imposed, there is no
2111 * need for the L_CODES extra codes used during heap construction. However
2112 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
2116 local ct_data near static_dtree[D_CODES];
2118 /* The static distance tree. (Actually a trivial tree since all codes use
2122 local ct_data near bl_tree[2 * BL_CODES + 1];
2124 /* Huffman tree for the bit lengths */
2126 typedef struct tree_desc {
2127 ct_data near *dyn_tree; /* the dynamic tree */
2128 ct_data near *static_tree; /* corresponding static tree or NULL */
2129 int near *extra_bits; /* extra bits for each code or NULL */
2130 int extra_base; /* base index for extra_bits */
2131 int elems; /* max number of elements in the tree */
2132 int max_length; /* max bit length for the codes */
2133 int max_code; /* largest code with non zero frequency */
2136 local tree_desc near l_desc =
2137 { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES,
2140 local tree_desc near d_desc =
2141 { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 };
2143 local tree_desc near bl_desc =
2144 { bl_tree, (ct_data near *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS,
2148 local ush near bl_count[MAX_BITS + 1];
2150 /* number of codes at each bit length for an optimal tree */
2152 local uch near bl_order[BL_CODES]
2153 = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
2155 /* The lengths of the bit length codes are sent in order of decreasing
2156 * probability, to avoid transmitting the lengths for unused bit length codes.
2159 local int near heap[2 * L_CODES + 1]; /* heap used to build the Huffman trees */
2160 local int heap_len; /* number of elements in the heap */
2161 local int heap_max; /* element of largest frequency */
2163 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
2164 * The same heap array is used to build all trees.
2167 local uch near depth[2 * L_CODES + 1];
2169 /* Depth of each subtree used as tie breaker for trees of equal frequency */
2171 local uch length_code[MAX_MATCH - MIN_MATCH + 1];
2173 /* length code for each normalized match length (0 == MIN_MATCH) */
2175 local uch dist_code[512];
2177 /* distance codes. The first 256 values correspond to the distances
2178 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2179 * the 15 bit distances.
2182 local int near base_length[LENGTH_CODES];
2184 /* First normalized length for each code (0 = MIN_MATCH) */
2186 local int near base_dist[D_CODES];
2188 /* First normalized distance for each code (0 = distance of 1) */
2191 /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */
2193 /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
2195 local uch near flag_buf[(LIT_BUFSIZE / 8)];
2197 /* flag_buf is a bit array distinguishing literals from lengths in
2198 * l_buf, thus indicating the presence or absence of a distance.
2201 local unsigned last_lit; /* running index in l_buf */
2202 local unsigned last_dist; /* running index in d_buf */
2203 local unsigned last_flags; /* running index in flag_buf */
2204 local uch flags; /* current flags not yet saved in flag_buf */
2205 local uch flag_bit; /* current bit used in flags */
2207 /* bits are filled in flags starting at bit 0 (least significant).
2208 * Note: these flags are overkill in the current code since we don't
2209 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
2212 local ulg opt_len; /* bit length of current block with optimal trees */
2213 local ulg static_len; /* bit length of current block with static trees */
2215 local ulg compressed_len; /* total bit length of compressed file */
2217 local ulg input_len; /* total byte length of input file */
2219 /* input_len is for debugging only since we can get it by other means. */
2221 ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
2222 int *file_method; /* pointer to DEFLATE or STORE */
2225 extern ulg bits_sent; /* bit length of the compressed data */
2226 extern long isize; /* byte length of input file */
2229 extern long block_start; /* window offset of current block */
2230 extern unsigned near strstart; /* window offset of current string */
2232 /* ===========================================================================
2233 * Local (static) routines in this file.
2236 local void init_block (void);
2237 local void pqdownheap (ct_data near * tree, int k);
2238 local void gen_bitlen (tree_desc near * desc);
2239 local void gen_codes (ct_data near * tree, int max_code);
2240 local void build_tree (tree_desc near * desc);
2241 local void scan_tree (ct_data near * tree, int max_code);
2242 local void send_tree (ct_data near * tree, int max_code);
2243 local int build_bl_tree (void);
2244 local void send_all_trees (int lcodes, int dcodes, int blcodes);
2245 local void compress_block (ct_data near * ltree, ct_data near * dtree);
2246 local void set_file_type (void);
2250 # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
2251 /* Send a code of the given tree. c and tree must not have side effects */
2254 # define send_code(c, tree) \
2255 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
2256 send_bits(tree[c].Code, tree[c].Len); }
2259 #define d_code(dist) \
2260 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2261 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2262 * must not have side effects. dist_code[256] and dist_code[257] are never
2266 /* the arguments must not have side effects */
2268 /* ===========================================================================
2269 * Allocate the match buffer, initialize the various tables and save the
2270 * location of the internal file attribute (ascii/binary) and method
2273 void ct_init(attr, methodp)
2274 ush *attr; /* pointer to internal file attribute */
2275 int *methodp; /* pointer to compression method */
2277 int n; /* iterates over tree elements */
2278 int bits; /* bit counter */
2279 int length; /* length value */
2280 int code; /* code value */
2281 int dist; /* distance index */
2284 file_method = methodp;
2285 compressed_len = input_len = 0L;
2287 if (static_dtree[0].Len != 0)
2288 return; /* ct_init already called */
2290 /* Initialize the mapping length (0..255) -> length code (0..28) */
2292 for (code = 0; code < LENGTH_CODES - 1; code++) {
2293 base_length[code] = length;
2294 for (n = 0; n < (1 << extra_lbits[code]); n++) {
2295 length_code[length++] = (uch) code;
2298 Assert(length == 256, "ct_init: length != 256");
2299 /* Note that the length 255 (match length 258) can be represented
2300 * in two different ways: code 284 + 5 bits or code 285, so we
2301 * overwrite length_code[255] to use the best encoding:
2303 length_code[length - 1] = (uch) code;
2305 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2307 for (code = 0; code < 16; code++) {
2308 base_dist[code] = dist;
2309 for (n = 0; n < (1 << extra_dbits[code]); n++) {
2310 dist_code[dist++] = (uch) code;
2313 Assert(dist == 256, "ct_init: dist != 256");
2314 dist >>= 7; /* from now on, all distances are divided by 128 */
2315 for (; code < D_CODES; code++) {
2316 base_dist[code] = dist << 7;
2317 for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
2318 dist_code[256 + dist++] = (uch) code;
2321 Assert(dist == 256, "ct_init: 256+dist != 512");
2323 /* Construct the codes of the static literal tree */
2324 for (bits = 0; bits <= MAX_BITS; bits++)
2328 static_ltree[n++].Len = 8, bl_count[8]++;
2330 static_ltree[n++].Len = 9, bl_count[9]++;
2332 static_ltree[n++].Len = 7, bl_count[7]++;
2334 static_ltree[n++].Len = 8, bl_count[8]++;
2335 /* Codes 286 and 287 do not exist, but we must include them in the
2336 * tree construction to get a canonical Huffman tree (longest code
2339 gen_codes((ct_data near *) static_ltree, L_CODES + 1);
2341 /* The static distance tree is trivial: */
2342 for (n = 0; n < D_CODES; n++) {
2343 static_dtree[n].Len = 5;
2344 static_dtree[n].Code = bi_reverse(n, 5);
2347 /* Initialize the first block of the first file: */
2351 /* ===========================================================================
2352 * Initialize a new block.
2354 local void init_block()
2356 int n; /* iterates over tree elements */
2358 /* Initialize the trees. */
2359 for (n = 0; n < L_CODES; n++)
2360 dyn_ltree[n].Freq = 0;
2361 for (n = 0; n < D_CODES; n++)
2362 dyn_dtree[n].Freq = 0;
2363 for (n = 0; n < BL_CODES; n++)
2364 bl_tree[n].Freq = 0;
2366 dyn_ltree[END_BLOCK].Freq = 1;
2367 opt_len = static_len = 0L;
2368 last_lit = last_dist = last_flags = 0;
2374 /* Index within the heap array of least frequent node in the Huffman tree */
2377 /* ===========================================================================
2378 * Remove the smallest element from the heap and recreate the heap with
2379 * one less element. Updates heap and heap_len.
2381 #define pqremove(tree, top) \
2383 top = heap[SMALLEST]; \
2384 heap[SMALLEST] = heap[heap_len--]; \
2385 pqdownheap(tree, SMALLEST); \
2388 /* ===========================================================================
2389 * Compares to subtrees, using the tree depth as tie breaker when
2390 * the subtrees have equal frequency. This minimizes the worst case length.
2392 #define smaller(tree, n, m) \
2393 (tree[n].Freq < tree[m].Freq || \
2394 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2396 /* ===========================================================================
2397 * Restore the heap property by moving down the tree starting at node k,
2398 * exchanging a node with the smallest of its two sons if necessary, stopping
2399 * when the heap property is re-established (each father smaller than its
2402 local void pqdownheap(tree, k)
2403 ct_data near *tree; /* the tree to restore */
2404 int k; /* node to move down */
2407 int j = k << 1; /* left son of k */
2409 while (j <= heap_len) {
2410 /* Set j to the smallest of the two sons: */
2411 if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
2414 /* Exit if v is smaller than both sons */
2415 if (smaller(tree, v, heap[j]))
2418 /* Exchange v with the smallest son */
2422 /* And continue down the tree, setting j to the left son of k */
2428 /* ===========================================================================
2429 * Compute the optimal bit lengths for a tree and update the total bit length
2430 * for the current block.
2431 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2432 * above are the tree nodes sorted by increasing frequency.
2433 * OUT assertions: the field len is set to the optimal bit length, the
2434 * array bl_count contains the frequencies for each bit length.
2435 * The length opt_len is updated; static_len is also updated if stree is
2438 local void gen_bitlen(desc)
2439 tree_desc near *desc; /* the tree descriptor */
2441 ct_data near *tree = desc->dyn_tree;
2442 int near *extra = desc->extra_bits;
2443 int base = desc->extra_base;
2444 int max_code = desc->max_code;
2445 int max_length = desc->max_length;
2446 ct_data near *stree = desc->static_tree;
2447 int h; /* heap index */
2448 int n, m; /* iterate over the tree elements */
2449 int bits; /* bit length */
2450 int xbits; /* extra bits */
2451 ush f; /* frequency */
2452 int overflow = 0; /* number of elements with bit length too large */
2454 for (bits = 0; bits <= MAX_BITS; bits++)
2457 /* In a first pass, compute the optimal bit lengths (which may
2458 * overflow in the case of the bit length tree).
2460 tree[heap[heap_max]].Len = 0; /* root of the heap */
2462 for (h = heap_max + 1; h < HEAP_SIZE; h++) {
2464 bits = tree[tree[n].Dad].Len + 1;
2465 if (bits > max_length)
2466 bits = max_length, overflow++;
2467 tree[n].Len = (ush) bits;
2468 /* We overwrite tree[n].Dad which is no longer needed */
2471 continue; /* not a leaf node */
2476 xbits = extra[n - base];
2478 opt_len += (ulg) f *(bits + xbits);
2481 static_len += (ulg) f *(stree[n].Len + xbits);
2486 Trace((stderr, "\nbit length overflow\n"));
2487 /* This happens for example on obj2 and pic of the Calgary corpus */
2489 /* Find the first bit length which could increase: */
2491 bits = max_length - 1;
2492 while (bl_count[bits] == 0)
2494 bl_count[bits]--; /* move one leaf down the tree */
2495 bl_count[bits + 1] += 2; /* move one overflow item as its brother */
2496 bl_count[max_length]--;
2497 /* The brother of the overflow item also moves one step up,
2498 * but this does not affect bl_count[max_length]
2501 } while (overflow > 0);
2503 /* Now recompute all bit lengths, scanning in increasing frequency.
2504 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2505 * lengths instead of fixing only the wrong ones. This idea is taken
2506 * from 'ar' written by Haruhiko Okumura.)
2508 for (bits = max_length; bits != 0; bits--) {
2514 if (tree[m].Len != (unsigned) bits) {
2516 (stderr, "code %d bits %d->%d\n", m, tree[m].Len,
2520 (long) tree[m].Len) * (long) tree[m].Freq;
2521 tree[m].Len = (ush) bits;
2528 /* ===========================================================================
2529 * Generate the codes for a given tree and bit counts (which need not be
2531 * IN assertion: the array bl_count contains the bit length statistics for
2532 * the given tree and the field len is set for all tree elements.
2533 * OUT assertion: the field code is set for all tree elements of non
2536 local void gen_codes(tree, max_code)
2537 ct_data near *tree; /* the tree to decorate */
2538 int max_code; /* largest code with non zero frequency */
2540 ush next_code[MAX_BITS + 1]; /* next code value for each bit length */
2541 ush code = 0; /* running code value */
2542 int bits; /* bit index */
2543 int n; /* code index */
2545 /* The distribution counts are first used to generate the code values
2546 * without bit reversal.
2548 for (bits = 1; bits <= MAX_BITS; bits++) {
2549 next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
2551 /* Check that the bit counts in bl_count are consistent. The last code
2554 Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
2555 "inconsistent bit counts");
2556 Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
2558 for (n = 0; n <= max_code; n++) {
2559 int len = tree[n].Len;
2563 /* Now reverse the bits */
2564 tree[n].Code = bi_reverse(next_code[len]++, len);
2566 Tracec(tree != static_ltree,
2567 (stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
2568 (isgraph(n) ? n : ' '), len, tree[n].Code,
2569 next_code[len] - 1));
2573 /* ===========================================================================
2574 * Construct one Huffman tree and assigns the code bit strings and lengths.
2575 * Update the total bit length for the current block.
2576 * IN assertion: the field freq is set for all tree elements.
2577 * OUT assertions: the fields len and code are set to the optimal bit length
2578 * and corresponding code. The length opt_len is updated; static_len is
2579 * also updated if stree is not null. The field max_code is set.
2581 local void build_tree(desc)
2582 tree_desc near *desc; /* the tree descriptor */
2584 ct_data near *tree = desc->dyn_tree;
2585 ct_data near *stree = desc->static_tree;
2586 int elems = desc->elems;
2587 int n, m; /* iterate over heap elements */
2588 int max_code = -1; /* largest code with non zero frequency */
2589 int node = elems; /* next internal node of the tree */
2591 /* Construct the initial heap, with least frequent element in
2592 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2593 * heap[0] is not used.
2595 heap_len = 0, heap_max = HEAP_SIZE;
2597 for (n = 0; n < elems; n++) {
2598 if (tree[n].Freq != 0) {
2599 heap[++heap_len] = max_code = n;
2606 /* The pkzip format requires that at least one distance code exists,
2607 * and that at least one bit should be sent even if there is only one
2608 * possible code. So to avoid special checks later on we force at least
2609 * two codes of non zero frequency.
2611 while (heap_len < 2) {
2612 int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
2618 static_len -= stree[new].Len;
2619 /* new is 0 or 1 so it does not have extra bits */
2621 desc->max_code = max_code;
2623 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2624 * establish sub-heaps of increasing lengths:
2626 for (n = heap_len / 2; n >= 1; n--)
2627 pqdownheap(tree, n);
2629 /* Construct the Huffman tree by repeatedly combining the least two
2633 pqremove(tree, n); /* n = node of least frequency */
2634 m = heap[SMALLEST]; /* m = node of next least frequency */
2636 heap[--heap_max] = n; /* keep the nodes sorted by frequency */
2637 heap[--heap_max] = m;
2639 /* Create a new node father of n and m */
2640 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2641 depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
2642 tree[n].Dad = tree[m].Dad = (ush) node;
2644 if (tree == bl_tree) {
2645 fprintf(stderr, "\nnode %d(%d), sons %d(%d) %d(%d)",
2646 node, tree[node].Freq, n, tree[n].Freq, m,
2650 /* and insert the new node in the heap */
2651 heap[SMALLEST] = node++;
2652 pqdownheap(tree, SMALLEST);
2654 } while (heap_len >= 2);
2656 heap[--heap_max] = heap[SMALLEST];
2658 /* At this point, the fields freq and dad are set. We can now
2659 * generate the bit lengths.
2661 gen_bitlen((tree_desc near *) desc);
2663 /* The field len is now set, we can generate the bit codes */
2664 gen_codes((ct_data near *) tree, max_code);
2667 /* ===========================================================================
2668 * Scan a literal or distance tree to determine the frequencies of the codes
2669 * in the bit length tree. Updates opt_len to take into account the repeat
2670 * counts. (The contribution of the bit length codes will be added later
2671 * during the construction of bl_tree.)
2673 local void scan_tree(tree, max_code)
2674 ct_data near *tree; /* the tree to be scanned */
2675 int max_code; /* and its largest code of non zero frequency */
2677 int n; /* iterates over all tree elements */
2678 int prevlen = -1; /* last emitted length */
2679 int curlen; /* length of current code */
2680 int nextlen = tree[0].Len; /* length of next code */
2681 int count = 0; /* repeat count of the current code */
2682 int max_count = 7; /* max repeat count */
2683 int min_count = 4; /* min repeat count */
2686 max_count = 138, min_count = 3;
2687 tree[max_code + 1].Len = (ush) 0xffff; /* guard */
2689 for (n = 0; n <= max_code; n++) {
2691 nextlen = tree[n + 1].Len;
2692 if (++count < max_count && curlen == nextlen) {
2694 } else if (count < min_count) {
2695 bl_tree[curlen].Freq += count;
2696 } else if (curlen != 0) {
2697 if (curlen != prevlen)
2698 bl_tree[curlen].Freq++;
2699 bl_tree[REP_3_6].Freq++;
2700 } else if (count <= 10) {
2701 bl_tree[REPZ_3_10].Freq++;
2703 bl_tree[REPZ_11_138].Freq++;
2708 max_count = 138, min_count = 3;
2709 } else if (curlen == nextlen) {
2710 max_count = 6, min_count = 3;
2712 max_count = 7, min_count = 4;
2717 /* ===========================================================================
2718 * Send a literal or distance tree in compressed form, using the codes in
2721 local void send_tree(tree, max_code)
2722 ct_data near *tree; /* the tree to be scanned */
2723 int max_code; /* and its largest code of non zero frequency */
2725 int n; /* iterates over all tree elements */
2726 int prevlen = -1; /* last emitted length */
2727 int curlen; /* length of current code */
2728 int nextlen = tree[0].Len; /* length of next code */
2729 int count = 0; /* repeat count of the current code */
2730 int max_count = 7; /* max repeat count */
2731 int min_count = 4; /* min repeat count */
2733 /* tree[max_code+1].Len = -1; *//* guard already set */
2735 max_count = 138, min_count = 3;
2737 for (n = 0; n <= max_code; n++) {
2739 nextlen = tree[n + 1].Len;
2740 if (++count < max_count && curlen == nextlen) {
2742 } else if (count < min_count) {
2744 send_code(curlen, bl_tree);
2745 } while (--count != 0);
2747 } else if (curlen != 0) {
2748 if (curlen != prevlen) {
2749 send_code(curlen, bl_tree);
2752 Assert(count >= 3 && count <= 6, " 3_6?");
2753 send_code(REP_3_6, bl_tree);
2754 send_bits(count - 3, 2);
2756 } else if (count <= 10) {
2757 send_code(REPZ_3_10, bl_tree);
2758 send_bits(count - 3, 3);
2761 send_code(REPZ_11_138, bl_tree);
2762 send_bits(count - 11, 7);
2767 max_count = 138, min_count = 3;
2768 } else if (curlen == nextlen) {
2769 max_count = 6, min_count = 3;
2771 max_count = 7, min_count = 4;
2776 /* ===========================================================================
2777 * Construct the Huffman tree for the bit lengths and return the index in
2778 * bl_order of the last bit length code to send.
2780 local int build_bl_tree()
2782 int max_blindex; /* index of last bit length code of non zero freq */
2784 /* Determine the bit length frequencies for literal and distance trees */
2785 scan_tree((ct_data near *) dyn_ltree, l_desc.max_code);
2786 scan_tree((ct_data near *) dyn_dtree, d_desc.max_code);
2788 /* Build the bit length tree: */
2789 build_tree((tree_desc near *) (&bl_desc));
2790 /* opt_len now includes the length of the tree representations, except
2791 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2794 /* Determine the number of bit length codes to send. The pkzip format
2795 * requires that at least 4 bit length codes be sent. (appnote.txt says
2796 * 3 but the actual value used is 4.)
2798 for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
2799 if (bl_tree[bl_order[max_blindex]].Len != 0)
2802 /* Update opt_len to include the bit length tree and counts */
2803 opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
2805 (stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len,
2811 /* ===========================================================================
2812 * Send the header for a block using dynamic Huffman trees: the counts, the
2813 * lengths of the bit length codes, the literal tree and the distance tree.
2814 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2816 local void send_all_trees(lcodes, dcodes, blcodes)
2817 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2819 int rank; /* index in bl_order */
2821 Assert(lcodes >= 257 && dcodes >= 1
2822 && blcodes >= 4, "not enough codes");
2823 Assert(lcodes <= L_CODES && dcodes <= D_CODES
2824 && blcodes <= BL_CODES, "too many codes");
2825 Tracev((stderr, "\nbl counts: "));
2826 send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */
2827 send_bits(dcodes - 1, 5);
2828 send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */
2829 for (rank = 0; rank < blcodes; rank++) {
2830 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2831 send_bits(bl_tree[bl_order[rank]].Len, 3);
2833 Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
2835 send_tree((ct_data near *) dyn_ltree, lcodes - 1); /* send the literal tree */
2836 Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
2838 send_tree((ct_data near *) dyn_dtree, dcodes - 1); /* send the distance tree */
2839 Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
2842 /* ===========================================================================
2843 * Determine the best encoding for the current block: dynamic trees, static
2844 * trees or store, and output the encoded block to the zip file. This function
2845 * returns the total compressed length for the file so far.
2847 ulg flush_block(buf, stored_len, eof)
2848 char *buf; /* input block, or NULL if too old */
2849 ulg stored_len; /* length of input block */
2850 int eof; /* true if this is the last block for a file */
2852 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2853 int max_blindex; /* index of last bit length code of non zero freq */
2855 flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
2857 /* Check if the file is ascii or binary */
2858 if (*file_type == (ush) UNKNOWN)
2861 /* Construct the literal and distance trees */
2862 build_tree((tree_desc near *) (&l_desc));
2863 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
2865 build_tree((tree_desc near *) (&d_desc));
2867 (stderr, "\ndist data: dyn %ld, stat %ld", opt_len,
2869 /* At this point, opt_len and static_len are the total bit lengths of
2870 * the compressed block data, excluding the tree representations.
2873 /* Build the bit length tree for the above two trees, and get the index
2874 * in bl_order of the last bit length code to send.
2876 max_blindex = build_bl_tree();
2878 /* Determine the best encoding. Compute first the block length in bytes */
2879 opt_lenb = (opt_len + 3 + 7) >> 3;
2880 static_lenb = (static_len + 3 + 7) >> 3;
2881 input_len += stored_len; /* for debugging only */
2885 "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2886 opt_lenb, opt_len, static_lenb, static_len, stored_len,
2887 last_lit, last_dist));
2889 if (static_lenb <= opt_lenb)
2890 opt_lenb = static_lenb;
2892 /* If compression failed and this is the first and last block,
2893 * and if the zip file can be seeked (to rewrite the local header),
2894 * the whole file is transformed into a stored file:
2898 if (stored_len <= opt_lenb && eof && compressed_len == 0L
2901 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2902 if (buf == (char *) 0)
2903 error_msg("block vanished\n");
2905 copy_block(buf, (unsigned) stored_len, 0); /* without header */
2906 compressed_len = stored_len << 3;
2907 *file_method = STORED;
2911 } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
2912 /* 4: two words for the lengths */
2914 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2915 * Otherwise we can't have processed more than WSIZE input bytes since
2916 * the last block flush, because compression would have been
2917 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2918 * transform a block into a stored block.
2920 send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */
2921 compressed_len = (compressed_len + 3 + 7) & ~7L;
2922 compressed_len += (stored_len + 4) << 3;
2924 copy_block(buf, (unsigned) stored_len, 1); /* with header */
2928 } else if (static_lenb == opt_lenb) {
2930 send_bits((STATIC_TREES << 1) + eof, 3);
2931 compress_block((ct_data near *) static_ltree,
2932 (ct_data near *) static_dtree);
2933 compressed_len += 3 + static_len;
2935 send_bits((DYN_TREES << 1) + eof, 3);
2936 send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1,
2938 compress_block((ct_data near *) dyn_ltree,
2939 (ct_data near *) dyn_dtree);
2940 compressed_len += 3 + opt_len;
2942 Assert(compressed_len == bits_sent, "bad compressed size");
2946 Assert(input_len == isize, "bad input size");
2948 compressed_len += 7; /* align on byte boundary */
2950 Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
2951 compressed_len - 7 * eof));
2953 return compressed_len >> 3;
2956 /* ===========================================================================
2957 * Save the match info and tally the frequency counts. Return true if
2958 * the current block must be flushed.
2960 int ct_tally(dist, lc)
2961 int dist; /* distance of matched string */
2962 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2964 l_buf[last_lit++] = (uch) lc;
2966 /* lc is the unmatched char */
2967 dyn_ltree[lc].Freq++;
2969 /* Here, lc is the match length - MIN_MATCH */
2970 dist--; /* dist = match distance - 1 */
2971 Assert((ush) dist < (ush) MAX_DIST &&
2972 (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) &&
2973 (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match");
2975 dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
2976 dyn_dtree[d_code(dist)].Freq++;
2978 d_buf[last_dist++] = (ush) dist;
2983 /* Output the flags if they fill a byte: */
2984 if ((last_lit & 7) == 0) {
2985 flag_buf[last_flags++] = flags;
2986 flags = 0, flag_bit = 1;
2988 /* Try to guess if it is profitable to stop the current block here */
2989 if ((last_lit & 0xfff) == 0) {
2990 /* Compute an upper bound for the compressed length */
2991 ulg out_length = (ulg) last_lit * 8L;
2992 ulg in_length = (ulg) strstart - block_start;
2995 for (dcode = 0; dcode < D_CODES; dcode++) {
2997 (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
3002 "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
3003 last_lit, last_dist, in_length, out_length,
3004 100L - out_length * 100L / in_length));
3005 if (last_dist < last_lit / 2 && out_length < in_length / 2)
3008 return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE);
3009 /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
3010 * on 16 bit machines and because stored blocks are restricted to
3015 /* ===========================================================================
3016 * Send the block data compressed using the given Huffman trees
3018 local void compress_block(ltree, dtree)
3019 ct_data near *ltree; /* literal tree */
3020 ct_data near *dtree; /* distance tree */
3022 unsigned dist; /* distance of matched string */
3023 int lc; /* match length or unmatched char (if dist == 0) */
3024 unsigned lx = 0; /* running index in l_buf */
3025 unsigned dx = 0; /* running index in d_buf */
3026 unsigned fx = 0; /* running index in flag_buf */
3027 uch flag = 0; /* current flags */
3028 unsigned code; /* the code to send */
3029 int extra; /* number of extra bits to send */
3034 flag = flag_buf[fx++];
3036 if ((flag & 1) == 0) {
3037 send_code(lc, ltree); /* send a literal byte */
3038 Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
3040 /* Here, lc is the match length - MIN_MATCH */
3041 code = length_code[lc];
3042 send_code(code + LITERALS + 1, ltree); /* send the length code */
3043 extra = extra_lbits[code];
3045 lc -= base_length[code];
3046 send_bits(lc, extra); /* send the extra length bits */
3049 /* Here, dist is the match distance - 1 */
3050 code = d_code(dist);
3051 Assert(code < D_CODES, "bad d_code");
3053 send_code(code, dtree); /* send the distance code */
3054 extra = extra_dbits[code];
3056 dist -= base_dist[code];
3057 send_bits(dist, extra); /* send the extra distance bits */
3059 } /* literal or match pair ? */
3061 } while (lx < last_lit);
3063 send_code(END_BLOCK, ltree);
3066 /* ===========================================================================
3067 * Set the file type to ASCII or BINARY, using a crude approximation:
3068 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3069 * IN assertion: the fields freq of dyn_ltree are set and the total of all
3070 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3072 local void set_file_type()
3075 unsigned ascii_freq = 0;
3076 unsigned bin_freq = 0;
3079 bin_freq += dyn_ltree[n++].Freq;
3081 ascii_freq += dyn_ltree[n++].Freq;
3082 while (n < LITERALS)
3083 bin_freq += dyn_ltree[n++].Freq;
3084 *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
3085 if (*file_type == BINARY && translate_eol) {
3086 error_msg("-l used on binary file\n");
3090 /* util.c -- utility functions for gzip support
3091 * Copyright (C) 1992-1993 Jean-loup Gailly
3092 * This is free software; you can redistribute it and/or modify it under the
3093 * terms of the GNU General Public License, see the file COPYING.
3098 #include <sys/types.h>
3100 #ifdef HAVE_UNISTD_H
3101 # include <unistd.h>
3107 #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
3108 # include <stdlib.h>
3113 /* ===========================================================================
3114 * Copy input to output unchanged: zcat == cat with --force.
3115 * IN assertion: insize bytes have already been read in inbuf.
3118 int in, out; /* input and output file descriptors */
3121 while (insize != 0 && (int) insize != EOF) {
3122 write_buf(out, (char *) inbuf, insize);
3123 bytes_out += insize;
3124 insize = read(in, (char *) inbuf, INBUFSIZ);
3126 if ((int) insize == EOF && errno != 0) {
3129 bytes_in = bytes_out;
3133 /* ========================================================================
3134 * Put string s in lower case, return s.
3141 for (t = s; *t; t++)
3146 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
3148 /* Provide missing strspn and strcspn functions. */
3150 int strspn (const char *s, const char *accept);
3151 int strcspn (const char *s, const char *reject);
3153 /* ========================================================================
3154 * Return the length of the maximum initial segment
3155 * of s which contains only characters in accept.
3157 int strspn(s, accept)
3161 register const char *p;
3162 register const char *a;
3163 register int count = 0;
3165 for (p = s; *p != '\0'; ++p) {
3166 for (a = accept; *a != '\0'; ++a) {
3177 /* ========================================================================
3178 * Return the length of the maximum inital segment of s
3179 * which contains no characters from reject.
3181 int strcspn(s, reject)
3185 register int count = 0;
3187 while (*s != '\0') {
3188 if (strchr(reject, *s++) != NULL)
3195 #endif /* NO_STRING_H */
3197 /* ========================================================================
3198 * Add an environment variable (if any) before argv, and update argc.
3199 * Return the expanded environment variable to be freed later, or NULL
3200 * if no options were added to argv.
3202 #define SEPARATOR " \t" /* separators in env variable */
3204 char *add_envopt(argcp, argvp, env)
3205 int *argcp; /* pointer to argc */
3206 char ***argvp; /* pointer to argv */
3207 char *env; /* name of environment variable */
3209 char *p; /* running pointer through env variable */
3210 char **oargv; /* runs through old argv array */
3211 char **nargv; /* runs through new argv array */
3212 int oargc = *argcp; /* old argc */
3213 int nargc = 0; /* number of arguments in env variable */
3215 env = (char *) getenv(env);
3219 p = (char *) xmalloc(strlen(env) + 1);
3220 env = strcpy(p, env); /* keep env variable intact */
3222 for (p = env; *p; nargc++) { /* move through env */
3223 p += strspn(p, SEPARATOR); /* skip leading separators */
3227 p += strcspn(p, SEPARATOR); /* find end of word */
3229 *p++ = '\0'; /* mark it */
3236 /* Allocate the new argv array, with an extra element just in case
3237 * the original arg list did not end with a NULL.
3239 nargv = (char **) calloc(*argcp + 1, sizeof(char *));
3242 error_msg(memory_exhausted);
3246 /* Copy the program name first */
3248 error_msg("argc<=0\n");
3249 *(nargv++) = *(oargv++);
3251 /* Then copy the environment args */
3252 for (p = env; nargc > 0; nargc--) {
3253 p += strspn(p, SEPARATOR); /* skip separators */
3254 *(nargv++) = p; /* store start */
3255 while (*p++); /* skip over word */
3258 /* Finally copy the old args and add a NULL (usual convention) */
3260 *(nargv++) = *(oargv++);
3265 /* ========================================================================
3266 * Display compression ratio on the given stream on 6 characters.
3268 void display_ratio(num, den, file)
3273 long ratio; /* 1000 times the compression ratio */
3276 ratio = 0; /* no compression */
3277 } else if (den < 2147483L) { /* (2**31 -1)/1000 */
3278 ratio = 1000L * num / den;
3280 ratio = num / (den / 1000L);
3288 fprintf(file, "%2ld.%1ld%%", ratio / 10L, ratio % 10L);
3292 /* zip.c -- compress files to the gzip or pkzip format
3293 * Copyright (C) 1992-1993 Jean-loup Gailly
3294 * This is free software; you can redistribute it and/or modify it under the
3295 * terms of the GNU General Public License, see the file COPYING.
3299 #include <sys/types.h>
3301 #ifdef HAVE_UNISTD_H
3302 # include <unistd.h>
3308 local ulg crc; /* crc on uncompressed file data */
3309 long header_bytes; /* number of bytes in gzip header */
3311 /* ===========================================================================
3312 * Deflate in to out.
3313 * IN assertions: the input and output buffers are cleared.
3314 * The variables time_stamp and save_orig_name are initialized.
3317 int in, out; /* input and output file descriptors */
3319 uch flags = 0; /* general purpose bit flags */
3320 ush attr = 0; /* ascii/binary flag */
3321 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
3327 /* Write the header to the gzip file. See algorithm.doc for the format */
3331 put_byte(GZIP_MAGIC[0]); /* magic header */
3332 put_byte(GZIP_MAGIC[1]);
3333 put_byte(DEFLATED); /* compression method */
3335 put_byte(flags); /* general flags */
3336 put_long(time_stamp);
3338 /* Write deflated file to zip file */
3342 ct_init(&attr, &method);
3343 lm_init(&deflate_flags);
3345 put_byte((uch) deflate_flags); /* extra flags */
3346 put_byte(OS_CODE); /* OS identifier */
3348 header_bytes = (long) outcnt;
3352 /* Write the crc and uncompressed size */
3355 header_bytes += 2 * sizeof(long);
3362 /* ===========================================================================
3363 * Read a new buffer from the current input file, perform end-of-line
3364 * translation, and update the crc and input file size.
3365 * IN assertion: size >= 2 (for end-of-line translation)
3367 int file_read(buf, size)
3373 Assert(insize == 0, "inbuf not empty");
3375 len = read(ifd, buf, size);
3376 if (len == (unsigned) (-1) || len == 0)
3379 crc = updcrc((uch *) buf, len);
3384 /* ===========================================================================
3385 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
3386 * (used for the compressed data only)
3393 write_buf(ofd, (char *) outbuf, outcnt);
3394 bytes_out += (ulg) outcnt;
projects / oweals / busybox.git / blob