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
32 /* These defines are very important for BusyBox. Without these,
33 * huge chunks of ram are pre-allocated making the BusyBox bss
34 * size Freaking Huge(tm), which is a bad thing.*/
38 /* I don't like nested includes, but the string and io functions are used
46 #define BB_DECLARE_EXTERN
47 #define bb_need_memory_exhausted
50 #define memzero(s, n) memset ((void *)(s), 0, (n))
53 # define RETSIGTYPE void
58 typedef unsigned char uch;
59 typedef unsigned short ush;
60 typedef unsigned long ulg;
62 /* Return codes from gzip */
67 /* Compression methods (see algorithm.doc) */
72 /* methods 4 to 7 reserved */
75 extern int method; /* compression method */
77 /* To save memory for 16 bit systems, some arrays are overlaid between
78 * the various modules:
79 * deflate: prev+head window d_buf l_buf outbuf
80 * unlzw: tab_prefix tab_suffix stack inbuf outbuf
81 * inflate: window inbuf
82 * unpack: window inbuf prefix_len
83 * unlzh: left+right window c_table inbuf c_len
84 * For compression, input is done in window[]. For decompression, output
85 * is done in window except for unlzw.
90 # define INBUFSIZ 0x2000 /* input buffer size */
92 # define INBUFSIZ 0x8000 /* input buffer size */
95 #define INBUF_EXTRA 64 /* required by unlzw() */
99 # define OUTBUFSIZ 8192 /* output buffer size */
101 # define OUTBUFSIZ 16384 /* output buffer size */
104 #define OUTBUF_EXTRA 2048 /* required by unlzw() */
108 # define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
110 # define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
115 # define EXTERN(type, array) extern type * array
116 # define DECLARE(type, array, size) type * array
117 # define ALLOC(type, array, size) { \
118 array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
119 if (array == NULL) error_msg(memory_exhausted); \
121 # define FREE(array) {if (array != NULL) free(array), array=NULL;}
123 # define EXTERN(type, array) extern type array[]
124 # define DECLARE(type, array, size) type array[size]
125 # define ALLOC(type, array, size)
129 EXTERN(uch, inbuf); /* input buffer */
130 EXTERN(uch, outbuf); /* output buffer */
131 EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
132 EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
133 #define tab_suffix window
135 # define tab_prefix prev /* hash link (see deflate.c) */
136 # define head (prev+WSIZE) /* hash head (see deflate.c) */
137 EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
139 # define tab_prefix0 prev
140 # define head tab_prefix1
141 EXTERN(ush, tab_prefix0); /* prefix for even codes */
142 EXTERN(ush, tab_prefix1); /* prefix for odd codes */
145 extern unsigned insize; /* valid bytes in inbuf */
146 extern unsigned inptr; /* index of next byte to be processed in inbuf */
147 extern unsigned outcnt; /* bytes in output buffer */
149 extern long bytes_in; /* number of input bytes */
150 extern long bytes_out; /* number of output bytes */
151 extern long header_bytes; /* number of bytes in gzip header */
153 #define isize bytes_in
154 /* for compatibility with old zip sources (to be cleaned) */
156 extern int ifd; /* input file descriptor */
157 extern int ofd; /* output file descriptor */
158 extern char ifname[]; /* input file name or "stdin" */
159 extern char ofname[]; /* output file name or "stdout" */
160 extern char *progname; /* program name */
162 extern long time_stamp; /* original time stamp (modification time) */
163 extern long ifile_size; /* input file size, -1 for devices (debug only) */
165 typedef int file_t; /* Do not use stdio */
167 #define NO_FILE (-1) /* in memory compression */
170 #define PACK_MAGIC "\037\036" /* Magic header for packed files */
171 #define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
172 #define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
173 #define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */
174 #define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
177 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
178 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
179 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
180 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
181 #define COMMENT 0x10 /* bit 4 set: file comment present */
182 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
183 #define RESERVED 0xC0 /* bit 6,7: reserved */
185 /* internal file attribute */
186 #define UNKNOWN 0xffff
191 # define WSIZE 0x8000 /* window size--must be a power of two, and */
192 #endif /* at least 32K for zip's deflate method */
195 #define MAX_MATCH 258
196 /* The minimum and maximum match lengths */
198 #define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
199 /* Minimum amount of lookahead, except at the end of the input file.
200 * See deflate.c for comments about the MIN_MATCH+1.
203 #define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
204 /* In order to simplify the code, particularly on 16 bit machines, match
205 * distances are limited to MAX_DIST instead of WSIZE.
208 extern int decrypt; /* flag to turn on decryption */
209 extern int exit_code; /* program exit code */
210 extern int verbose; /* be verbose (-v) */
211 extern int quiet; /* be quiet (-q) */
212 extern int test; /* check .z file integrity */
213 extern int save_orig_name; /* set if original name must be saved */
215 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
216 #define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
218 /* put_byte is used for the compressed output, put_ubyte for the
219 * uncompressed output. However unlzw() uses window for its
220 * suffix table instead of its output buffer, so it does not use put_ubyte
221 * (to be cleaned up).
223 #define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
225 #define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
228 /* Output a 16 bit value, lsb first */
229 #define put_short(w) \
230 { if (outcnt < OUTBUFSIZ-2) { \
231 outbuf[outcnt++] = (uch) ((w) & 0xff); \
232 outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
234 put_byte((uch)((w) & 0xff)); \
235 put_byte((uch)((ush)(w) >> 8)); \
239 /* Output a 32 bit value to the bit stream, lsb first */
240 #define put_long(n) { \
241 put_short((n) & 0xffff); \
242 put_short(((ulg)(n)) >> 16); \
245 #define seekable() 0 /* force sequential output */
246 #define translate_eol 0 /* no option -a yet */
248 #define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
250 /* Macros for getting two-byte and four-byte header values */
251 #define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
252 #define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
254 /* Diagnostic functions */
256 # define Assert(cond,msg) {if(!(cond)) error_msg(msg);}
257 # define Trace(x) fprintf x
258 # define Tracev(x) {if (verbose) fprintf x ;}
259 # define Tracevv(x) {if (verbose>1) fprintf x ;}
260 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
261 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
263 # define Assert(cond,msg)
268 # define Tracecv(c,x)
271 #define WARN(msg) {if (!quiet) fprintf msg ; \
272 if (exit_code == OK) exit_code = WARNING;}
276 extern int zip (int in, int out);
277 extern int file_read (char *buf, unsigned size);
280 extern int unzip (int in, int out);
281 extern int check_zipfile (int in);
284 extern int unpack (int in, int out);
287 extern int unlzh (int in, int out);
290 RETSIGTYPE abort_gzip (void);
293 void lm_init (ush * flags);
297 void ct_init (ush * attr, int *method);
298 int ct_tally (int dist, int lc);
299 ulg flush_block (char *buf, ulg stored_len, int eof);
302 void bi_init (file_t zipfile);
303 void send_bits (int value, int length);
304 unsigned bi_reverse (unsigned value, int length);
305 void bi_windup (void);
306 void copy_block (char *buf, unsigned len, int header);
307 extern int (*read_buf) (char *buf, unsigned size);
310 extern int copy (int in, int out);
311 extern ulg updcrc (uch * s, unsigned n);
312 extern void clear_bufs (void);
313 extern int fill_inbuf (int eof_ok);
314 extern void flush_outbuf (void);
315 extern void flush_window (void);
316 extern void write_buf (int fd, void * buf, unsigned cnt);
317 extern char *strlwr (char *s);
318 extern char *add_envopt (int *argcp, char ***argvp, char *env);
319 extern void read_error_msg (void);
320 extern void write_error_msg (void);
321 extern void display_ratio (long num, long den, FILE * file);
324 extern int inflate (void);
326 /* lzw.h -- define the lzw functions.
327 * Copyright (C) 1992-1993 Jean-loup Gailly.
328 * This is free software; you can redistribute it and/or modify it under the
329 * terms of the GNU General Public License, see the file COPYING.
332 #if !defined(OF) && defined(lint)
339 #define INIT_BITS 9 /* Initial number of bits per code */
341 #define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
342 /* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
343 * It's a pity that old uncompress does not check bit 0x20. That makes
344 * extension of the format actually undesirable because old compress
345 * would just crash on the new format instead of giving a meaningful
346 * error message. It does check the number of bits, but it's more
347 * helpful to say "unsupported format, get a new version" than
348 * "can only handle 16 bits".
351 #define BLOCK_MODE 0x80
352 /* Block compression: if table is full and compression rate is dropping,
353 * clear the dictionary.
356 #define LZW_RESERVED 0x60 /* reserved bits */
358 #define CLEAR 256 /* flush the dictionary */
359 #define FIRST (CLEAR+1) /* first free entry */
361 extern int maxbits; /* max bits per code for LZW */
362 extern int block_mode; /* block compress mode -C compatible with 2.0 */
364 /* revision.h -- define the version number
365 * Copyright (C) 1992-1993 Jean-loup Gailly.
366 * This is free software; you can redistribute it and/or modify it under the
367 * terms of the GNU General Public License, see the file COPYING.
370 #define VERSION "1.2.4"
372 #define REVDATE "18 Aug 93"
374 /* This version does not support compression into old compress format: */
379 /* tailor.h -- target dependent definitions
380 * Copyright (C) 1992-1993 Jean-loup Gailly.
381 * This is free software; you can redistribute it and/or modify it under the
382 * terms of the GNU General Public License, see the file COPYING.
385 /* The target dependent definitions should be defined here only.
386 * The target dependent functions should be defined in tailor.c.
390 #if defined(__MSDOS__) && !defined(MSDOS)
394 #if defined(__OS2__) && !defined(OS2)
398 #if defined(OS2) && defined(MSDOS) /* MS C under OS/2 */
404 /* DJGPP version 1.09+ on MS-DOS.
405 * The DJGPP 1.09 stat() function must be upgraded before gzip will
407 * No need for DIRENT, since <unistd.h> defines POSIX_SOURCE which
421 # define HAVE_SYS_UTIME_H
425 # define PATH_SEP2 '\\'
426 # define PATH_SEP3 ':'
427 # define MAX_PATH_LEN 128
428 # define NO_MULTIPLE_DOTS
429 # define MAX_EXT_CHARS 3
430 # define Z_SUFFIX "z"
433 # define STDC_HEADERS
434 # define NO_SIZE_CHECK
435 # define casemap(c) tolow(c) /* Force file names to lower case */
437 # define OS_CODE 0x00
438 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
439 # if !defined(NO_ASM) && !defined(ASMV)
447 # define PATH_SEP2 '\\'
448 # define PATH_SEP3 ':'
449 # define MAX_PATH_LEN 260
451 # define NO_MULTIPLE_DOTS
452 # define MAX_EXT_CHARS 3
453 # define Z_SUFFIX "z"
454 # define casemap(c) tolow(c)
458 # define STDC_HEADERS
460 # define OS_CODE 0x06
461 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
463 # define HAVE_SYS_UTIME_H
470 # define HAVE_SYS_UTIME_H
473 # define EXPAND(argc,argv) \
474 {_response(&argc, &argv); _wildcard(&argc, &argv);}
483 # define EXPAND(argc,argv) \
484 {response_expand(&argc, &argv);}
488 #ifdef WIN32 /* Windows NT */
489 # define HAVE_SYS_UTIME_H
491 # define PATH_SEP2 '\\'
492 # define PATH_SEP3 ':'
493 # define MAX_PATH_LEN 260
496 # define STDC_HEADERS
497 # define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
501 # define NO_MULTIPLE_DOTS
502 # define MAX_EXT_CHARS 3
503 # define Z_SUFFIX "z"
504 # define casemap(c) tolow(c) /* Force file names to lower case */
506 # define OS_CODE 0x0b
513 /* Turbo C 2.0 does not accept static allocations of large arrays */
514 void *fcalloc(unsigned items, unsigned size);
515 void fcfree(void *ptr);
518 # define fcalloc(nitems,itemsize) halloc((long)(nitems),(itemsize))
519 # define fcfree(ptr) hfree(ptr)
523 # define fcalloc(items,size) calloc((items),(size))
525 # define fcalloc(items,size) malloc((size_t)(items)*(size_t)(size))
527 # define fcfree(ptr) free(ptr)
530 #if defined(VAXC) || defined(VMS)
531 # define PATH_SEP ']'
532 # define PATH_SEP2 ':'
533 # define SUFFIX_SEP ';'
534 # define NO_MULTIPLE_DOTS
535 # define Z_SUFFIX "-gz"
537 # define casemap(c) tolow(c)
538 # define OS_CODE 0x02
539 # define OPTIONS_VAR "GZIP_OPT"
540 # define STDC_HEADERS
542 # define EXPAND(argc,argv) vms_expand_args(&argc,&argv);
544 # define unlink delete
552 # define PATH_SEP2 ':'
553 # define STDC_HEADERS
554 # define OS_CODE 0x01
558 # define HAVE_UNISTD_H
560 # define NO_STDIN_FSTAT
565 # include <fcntl.h> /* for read() and write() */
566 # define direct dirent
567 extern void _expand_args(int *argc, char ***argv);
569 # define EXPAND(argc,argv) _expand_args(&argc,&argv);
570 # undef O_BINARY /* disable useless --ascii option */
574 #if defined(ATARI) || defined(atarist)
575 # ifndef STDC_HEADERS
576 # define STDC_HEADERS
577 # define HAVE_UNISTD_H
581 # define OS_CODE 0x05
583 # define PATH_SEP2 '\\'
584 # define PATH_SEP3 ':'
585 # define MAX_PATH_LEN 128
586 # define NO_MULTIPLE_DOTS
587 # define MAX_EXT_CHARS 3
588 # define Z_SUFFIX "z"
590 # define casemap(c) tolow(c) /* Force file names to lower case */
596 # define PATH_SEP ':'
599 # define NO_STDIN_FSTAT
602 # define chmod(file, mode) (0)
603 # define OPEN(name, flags, mode) open(name, flags)
604 # define OS_CODE 0x07
606 # define isatty(fd) ((fd) <= 2)
610 #ifdef __50SERIES /* Prime/PRIMOS */
611 # define PATH_SEP '>'
612 # define STDC_HEADERS
617 # define NO_STDIN_FSTAT
618 # define NO_SIZE_CHECK
621 # define casemap(c) tolow(c) /* Force file names to lower case */
622 # define put_char(c) put_byte((c) & 0x7F)
623 # define get_char(c) ascii2pascii(get_byte())
624 # define OS_CODE 0x0F /* temporary, subject to change */
626 # undef SIGTERM /* We don't want a signal handler for SIGTERM */
630 #if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */
631 # define NOMEMCPY /* problem with overlapping copies */
635 # define OS_CODE 0x0a
639 # define NO_ST_INO /* don't rely on inode numbers */
643 /* Common defaults */
646 # define OS_CODE 0x03 /* assume Unix */
650 # define PATH_SEP '/'
654 # define casemap(c) (c)
658 # define OPTIONS_VAR "GZIP"
662 # define Z_SUFFIX ".gz"
666 # define MAX_SUFFIX MAX_EXT_CHARS
668 # define MAX_SUFFIX 30
671 #ifndef MAKE_LEGAL_NAME
672 # ifdef NO_MULTIPLE_DOTS
673 # define MAKE_LEGAL_NAME(name) make_simple_name(name)
675 # define MAKE_LEGAL_NAME(name)
681 /* keep at least MIN_PART chars between dots in a file name. */
685 # define EXPAND(argc,argv)
692 #ifndef SET_BINARY_MODE
693 # define SET_BINARY_MODE(fd)
697 # define OPEN(name, flags, mode) open(name, flags, mode)
701 # define get_char() get_byte()
705 # define put_char(c) put_byte(c)
707 /* bits.c -- output variable-length bit strings
708 * Copyright (C) 1992-1993 Jean-loup Gailly
709 * This is free software; you can redistribute it and/or modify it under the
710 * terms of the GNU General Public License, see the file COPYING.
717 * Output variable-length bit strings. Compression can be done
718 * to a file or to memory. (The latter is not supported in this version.)
722 * The PKZIP "deflate" file format interprets compressed file data
723 * as a sequence of bits. Multi-bit strings in the file may cross
724 * byte boundaries without restriction.
726 * The first bit of each byte is the low-order bit.
728 * The routines in this file allow a variable-length bit value to
729 * be output right-to-left (useful for literal values). For
730 * left-to-right output (useful for code strings from the tree routines),
731 * the bits must have been reversed first with bi_reverse().
733 * For in-memory compression, the compressed bit stream goes directly
734 * into the requested output buffer. The input data is read in blocks
735 * by the mem_read() function. The buffer is limited to 64K on 16 bit
740 * void bi_init (FILE *zipfile)
741 * Initialize the bit string routines.
743 * void send_bits (int value, int length)
744 * Write out a bit string, taking the source bits right to
747 * int bi_reverse (int value, int length)
748 * Reverse the bits of a bit string, taking the source bits left to
749 * right and emitting them right to left.
751 * void bi_windup (void)
752 * Write out any remaining bits in an incomplete byte.
754 * void copy_block(char *buf, unsigned len, int header)
755 * Copy a stored block to the zip file, storing first the length and
756 * its one's complement if requested.
764 /* ===========================================================================
765 * Local data used by the "bit string" routines.
768 local file_t zfile; /* output gzip file */
770 local unsigned short bi_buf;
772 /* Output buffer. bits are inserted starting at the bottom (least significant
776 #define Buf_size (8 * 2*sizeof(char))
777 /* Number of bits used within bi_buf. (bi_buf might be implemented on
778 * more than 16 bits on some systems.)
783 /* Number of valid bits in bi_buf. All bits above the last valid bit
787 int (*read_buf) (char *buf, unsigned size);
789 /* Current input function. Set to mem_read for in-memory compression */
792 ulg bits_sent; /* bit length of the compressed data */
795 /* ===========================================================================
796 * Initialize the bit string routines.
798 void bi_init(zipfile)
799 file_t zipfile; /* output zip file, NO_FILE for in-memory compression */
808 /* Set the defaults for file compression. They are set by memcompress
809 * for in-memory compression.
811 if (zfile != NO_FILE) {
812 read_buf = file_read;
816 /* ===========================================================================
817 * Send a value on a given number of bits.
818 * IN assertion: length <= 16 and value fits in length bits.
820 void send_bits(value, length)
821 int value; /* value to send */
822 int length; /* number of bits */
825 Tracev((stderr, " l %2d v %4x ", length, value));
826 Assert(length > 0 && length <= 15, "invalid length");
827 bits_sent += (ulg) length;
829 /* If not enough room in bi_buf, use (valid) bits from bi_buf and
830 * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
831 * unused bits in value.
833 if (bi_valid > (int) Buf_size - length) {
834 bi_buf |= (value << bi_valid);
836 bi_buf = (ush) value >> (Buf_size - bi_valid);
837 bi_valid += length - Buf_size;
839 bi_buf |= value << bi_valid;
844 /* ===========================================================================
845 * Reverse the first len bits of a code, using straightforward code (a faster
846 * method would use a table)
847 * IN assertion: 1 <= len <= 15
849 unsigned bi_reverse(code, len)
850 unsigned code; /* the value to invert */
851 int len; /* its bit length */
853 register unsigned res = 0;
857 code >>= 1, res <<= 1;
862 /* ===========================================================================
863 * Write out any remaining bits in an incomplete byte.
869 } else if (bi_valid > 0) {
875 bits_sent = (bits_sent + 7) & ~7;
879 /* ===========================================================================
880 * Copy a stored block to the zip file, storing first the length and its
881 * one's complement if requested.
883 void copy_block(buf, len, header)
884 char *buf; /* the input data */
885 unsigned len; /* its length */
886 int header; /* true if block header must be written */
888 bi_windup(); /* align on byte boundary */
891 put_short((ush) len);
892 put_short((ush) ~ len);
898 bits_sent += (ulg) len << 3;
911 /* deflate.c -- compress data using the deflation algorithm
912 * Copyright (C) 1992-1993 Jean-loup Gailly
913 * This is free software; you can redistribute it and/or modify it under the
914 * terms of the GNU General Public License, see the file COPYING.
920 * Identify new text as repetitions of old text within a fixed-
921 * length sliding window trailing behind the new text.
925 * The "deflation" process depends on being able to identify portions
926 * of the input text which are identical to earlier input (within a
927 * sliding window trailing behind the input currently being processed).
929 * The most straightforward technique turns out to be the fastest for
930 * most input files: try all possible matches and select the longest.
931 * The key feature of this algorithm is that insertions into the string
932 * dictionary are very simple and thus fast, and deletions are avoided
933 * completely. Insertions are performed at each input character, whereas
934 * string matches are performed only when the previous match ends. So it
935 * is preferable to spend more time in matches to allow very fast string
936 * insertions and avoid deletions. The matching algorithm for small
937 * strings is inspired from that of Rabin & Karp. A brute force approach
938 * is used to find longer strings when a small match has been found.
939 * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
940 * (by Leonid Broukhis).
941 * A previous version of this file used a more sophisticated algorithm
942 * (by Fiala and Greene) which is guaranteed to run in linear amortized
943 * time, but has a larger average cost, uses more memory and is patented.
944 * However the F&G algorithm may be faster for some highly redundant
945 * files if the parameter max_chain_length (described below) is too large.
949 * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
950 * I found it in 'freeze' written by Leonid Broukhis.
951 * Thanks to many info-zippers for bug reports and testing.
955 * APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
957 * A description of the Rabin and Karp algorithm is given in the book
958 * "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
960 * Fiala,E.R., and Greene,D.H.
961 * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
965 * void lm_init (int pack_level, ush *flags)
966 * Initialize the "longest match" routines for a new file
969 * Processes a new input file and return its compressed length. Sets
970 * the compressed length, crc, deflate flags and internal file
976 /* ===========================================================================
977 * Configuration parameters
980 /* Compile with MEDIUM_MEM to reduce the memory requirements or
981 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
982 * entire input file can be held in memory (not possible on 16 bit systems).
983 * Warning: defining these symbols affects HASH_BITS (see below) and thus
984 * affects the compression ratio. The compressed output
985 * is still correct, and might even be smaller in some cases.
989 # define HASH_BITS 13 /* Number of bits used to hash strings */
992 # define HASH_BITS 14
995 # define HASH_BITS 15
996 /* For portability to 16 bit machines, do not use values above 15. */
999 /* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
1000 * window with tab_suffix. Check that we can do this:
1002 #if (WSIZE<<1) > (1<<BITS)
1003 error:cannot overlay window with tab_suffix and prev with tab_prefix0
1005 #if HASH_BITS > BITS-1
1006 error:cannot overlay head with tab_prefix1
1008 #define HASH_SIZE (unsigned)(1<<HASH_BITS)
1009 #define HASH_MASK (HASH_SIZE-1)
1010 #define WMASK (WSIZE-1)
1011 /* HASH_SIZE and WSIZE must be powers of two */
1013 /* Tail of hash chains */
1016 /* speed options for the general purpose bit flag */
1018 # define TOO_FAR 4096
1020 /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
1021 /* ===========================================================================
1022 * Local data used by the "longest match" routines.
1025 typedef unsigned IPos;
1027 /* A Pos is an index in the character window. We use short instead of int to
1028 * save space in the various tables. IPos is used only for parameter passing.
1031 /* DECLARE(uch, window, 2L*WSIZE); */
1032 /* Sliding window. Input bytes are read into the second half of the window,
1033 * and move to the first half later to keep a dictionary of at least WSIZE
1034 * bytes. With this organization, matches are limited to a distance of
1035 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
1036 * performed with a length multiple of the block size. Also, it limits
1037 * the window size to 64K, which is quite useful on MSDOS.
1038 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
1039 * be less efficient).
1042 /* DECLARE(Pos, prev, WSIZE); */
1043 /* Link to older string with same hash index. To limit the size of this
1044 * array to 64K, this link is maintained only for the last 32K strings.
1045 * An index in this array is thus a window index modulo 32K.
1048 /* DECLARE(Pos, head, 1<<HASH_BITS); */
1049 /* Heads of the hash chains or NIL. */
1051 ulg window_size = (ulg) 2 * WSIZE;
1053 /* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
1054 * input file length plus MIN_LOOKAHEAD.
1059 /* window position at the beginning of the current output block. Gets
1060 * negative when the window is moved backwards.
1063 local unsigned ins_h; /* hash index of string to be inserted */
1065 #define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
1066 /* Number of bits by which ins_h and del_h must be shifted at each
1067 * input step. It must be such that after MIN_MATCH steps, the oldest
1068 * byte no longer takes part in the hash key, that is:
1069 * H_SHIFT * MIN_MATCH >= HASH_BITS
1072 unsigned int near prev_length;
1074 /* Length of the best match at previous step. Matches not greater than this
1075 * are discarded. This is used in the lazy match evaluation.
1078 unsigned near strstart; /* start of string to insert */
1079 unsigned near match_start; /* start of matching string */
1080 local int eofile; /* flag set at end of input file */
1081 local unsigned lookahead; /* number of valid bytes ahead in window */
1083 unsigned near max_chain_length;
1085 /* To speed up deflation, hash chains are never searched beyond this length.
1086 * A higher limit improves compression ratio but degrades the speed.
1089 local unsigned int max_lazy_match;
1091 /* Attempt to find a better match only when the current match is strictly
1092 * smaller than this value. This mechanism is used only for compression
1095 #define max_insert_length max_lazy_match
1096 /* Insert new strings in the hash table only if the match length
1097 * is not greater than this length. This saves time but degrades compression.
1098 * max_insert_length is used only for compression levels <= 3.
1101 unsigned near good_match;
1103 /* Use a faster search when the previous match is longer than this */
1106 /* Values for max_lazy_match, good_match and max_chain_length, depending on
1107 * the desired pack level (0..9). The values given below have been tuned to
1108 * exclude worst case performance for pathological files. Better values may be
1109 * found for specific files.
1112 typedef struct config {
1113 ush good_length; /* reduce lazy search above this match length */
1114 ush max_lazy; /* do not perform lazy search above this match length */
1115 ush nice_length; /* quit search above this match length */
1120 # define nice_match MAX_MATCH
1122 int near nice_match; /* Stop searching when current match exceeds this */
1125 local config configuration_table =
1126 /* 9 */ { 32, 258, 258, 4096 };
1127 /* maximum compression */
1129 /* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
1130 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
1135 /* result of memcmp for equal strings */
1137 /* ===========================================================================
1138 * Prototypes for local functions.
1140 local void fill_window (void);
1142 int longest_match (IPos cur_match);
1145 void match_init (void); /* asm code initialization */
1149 local void check_match (IPos start, IPos match, int length);
1152 /* ===========================================================================
1153 * Update a hash value with the given input byte
1154 * IN assertion: all calls to to UPDATE_HASH are made with consecutive
1155 * input characters, so that a running hash key can be computed from the
1156 * previous key instead of complete recalculation each time.
1158 #define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
1160 /* ===========================================================================
1161 * Insert string s in the dictionary and set match_head to the previous head
1162 * of the hash chain (the most recent string with same hash key). Return
1163 * the previous length of the hash chain.
1164 * IN assertion: all calls to to INSERT_STRING are made with consecutive
1165 * input characters and the first MIN_MATCH bytes of s are valid
1166 * (except for the last MIN_MATCH-1 bytes of the input file).
1168 #define INSERT_STRING(s, match_head) \
1169 (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
1170 prev[(s) & WMASK] = match_head = head[ins_h], \
1173 /* ===========================================================================
1174 * Initialize the "longest match" routines for a new file
1177 ush *flags; /* general purpose bit flag */
1179 register unsigned j;
1181 /* Initialize the hash table. */
1182 #if defined(MAXSEG_64K) && HASH_BITS == 15
1183 for (j = 0; j < HASH_SIZE; j++)
1186 memzero((char *) head, HASH_SIZE * sizeof(*head));
1188 /* prev will be initialized on the fly */
1190 /* Set the default configuration parameters:
1192 max_lazy_match = configuration_table.max_lazy;
1193 good_match = configuration_table.good_length;
1195 nice_match = configuration_table.nice_length;
1197 max_chain_length = configuration_table.max_chain;
1199 /* ??? reduce max_chain_length for binary files */
1204 match_init(); /* initialize the asm code */
1207 lookahead = read_buf((char *) window,
1208 sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
1210 if (lookahead == 0 || lookahead == (unsigned) EOF) {
1211 eofile = 1, lookahead = 0;
1215 /* Make sure that we always have enough lookahead. This is important
1216 * if input comes from a device such as a tty.
1218 while (lookahead < MIN_LOOKAHEAD && !eofile)
1222 for (j = 0; j < MIN_MATCH - 1; j++)
1223 UPDATE_HASH(ins_h, window[j]);
1224 /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
1225 * not important since only literal bytes will be emitted.
1229 /* ===========================================================================
1230 * Set match_start to the longest match starting at the given string and
1231 * return its length. Matches shorter or equal to prev_length are discarded,
1232 * in which case the result is equal to prev_length and match_start is
1234 * IN assertions: cur_match is the head of the hash chain for the current
1235 * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
1238 /* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
1239 * match.s. The code is functionally equivalent, so you can use the C version
1242 int longest_match(cur_match)
1243 IPos cur_match; /* current match */
1245 unsigned chain_length = max_chain_length; /* max hash chain length */
1246 register uch *scan = window + strstart; /* current string */
1247 register uch *match; /* matched string */
1248 register int len; /* length of current match */
1249 int best_len = prev_length; /* best match length so far */
1252 strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL;
1253 /* Stop when cur_match becomes <= limit. To simplify the code,
1254 * we prevent matches with the string of window index 0.
1257 /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
1258 * It is easy to get rid of this optimization if necessary.
1260 #if HASH_BITS < 8 || MAX_MATCH != 258
1261 error:Code too clever
1264 /* Compare two bytes at a time. Note: this is not always beneficial.
1265 * Try with and without -DUNALIGNED_OK to check.
1267 register uch *strend = window + strstart + MAX_MATCH - 1;
1268 register ush scan_start = *(ush *) scan;
1269 register ush scan_end = *(ush *) (scan + best_len - 1);
1271 register uch *strend = window + strstart + MAX_MATCH;
1272 register uch scan_end1 = scan[best_len - 1];
1273 register uch scan_end = scan[best_len];
1276 /* Do not waste too much time if we already have a good match: */
1277 if (prev_length >= good_match) {
1280 Assert(strstart <= window_size - MIN_LOOKAHEAD,
1281 "insufficient lookahead");
1284 Assert(cur_match < strstart, "no future");
1285 match = window + cur_match;
1287 /* Skip to next match if the match length cannot increase
1288 * or if the match length is less than 2:
1290 #if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
1291 /* This code assumes sizeof(unsigned short) == 2. Do not use
1292 * UNALIGNED_OK if your compiler uses a different size.
1294 if (*(ush *) (match + best_len - 1) != scan_end ||
1295 *(ush *) match != scan_start)
1298 /* It is not necessary to compare scan[2] and match[2] since they are
1299 * always equal when the other bytes match, given that the hash keys
1300 * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at
1301 * strstart+3, +5, ... up to strstart+257. We check for insufficient
1302 * lookahead only every 4th comparison; the 128th check will be made
1303 * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
1304 * necessary to put more guard bytes at the end of the window, or
1305 * to check more often for insufficient lookahead.
1309 } while (*(ush *) (scan += 2) == *(ush *) (match += 2) &&
1310 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1311 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1312 *(ush *) (scan += 2) == *(ush *) (match += 2) &&
1314 /* The funny "do {}" generates better code on most compilers */
1316 /* Here, scan <= window+strstart+257 */
1317 Assert(scan <= window + (unsigned) (window_size - 1), "wild scan");
1318 if (*scan == *match)
1321 len = (MAX_MATCH - 1) - (int) (strend - scan);
1322 scan = strend - (MAX_MATCH - 1);
1324 #else /* UNALIGNED_OK */
1326 if (match[best_len] != scan_end ||
1327 match[best_len - 1] != scan_end1 ||
1328 *match != *scan || *++match != scan[1])
1331 /* The check at best_len-1 can be removed because it will be made
1332 * again later. (This heuristic is not always a win.)
1333 * It is not necessary to compare scan[2] and match[2] since they
1334 * are always equal when the other bytes match, given that
1335 * the hash keys are equal and that HASH_BITS >= 8.
1339 /* We check for insufficient lookahead only every 8th comparison;
1340 * the 256th check will be made at strstart+258.
1343 } while (*++scan == *++match && *++scan == *++match &&
1344 *++scan == *++match && *++scan == *++match &&
1345 *++scan == *++match && *++scan == *++match &&
1346 *++scan == *++match && *++scan == *++match &&
1349 len = MAX_MATCH - (int) (strend - scan);
1350 scan = strend - MAX_MATCH;
1352 #endif /* UNALIGNED_OK */
1354 if (len > best_len) {
1355 match_start = cur_match;
1357 if (len >= nice_match)
1360 scan_end = *(ush *) (scan + best_len - 1);
1362 scan_end1 = scan[best_len - 1];
1363 scan_end = scan[best_len];
1366 } while ((cur_match = prev[cur_match & WMASK]) > limit
1367 && --chain_length != 0);
1374 /* ===========================================================================
1375 * Check that the match at match_start is indeed a match.
1377 local void check_match(start, match, length)
1381 /* check that the match is indeed a match */
1382 if (memcmp((char *) window + match,
1383 (char *) window + start, length) != EQUAL) {
1385 " start %d, match %d, length %d\n", start, match, length);
1386 error_msg("invalid match");
1389 fprintf(stderr, "\\[%d,%d]", start - match, length);
1391 putc(window[start++], stderr);
1392 } while (--length != 0);
1396 # define check_match(start, match, length)
1399 /* ===========================================================================
1400 * Fill the window when the lookahead becomes insufficient.
1401 * Updates strstart and lookahead, and sets eofile if end of input file.
1402 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
1403 * OUT assertions: at least one byte has been read, or eofile is set;
1404 * file reads are performed for at least two bytes (required for the
1405 * translate_eol option).
1407 local void fill_window()
1409 register unsigned n, m;
1412 (unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
1413 /* Amount of free space at the end of the window. */
1415 /* If the window is almost full and there is insufficient lookahead,
1416 * move the upper half to the lower one to make room in the upper half.
1418 if (more == (unsigned) EOF) {
1419 /* Very unlikely, but possible on 16 bit machine if strstart == 0
1420 * and lookahead == 1 (input done one byte at time)
1423 } else if (strstart >= WSIZE + MAX_DIST) {
1424 /* By the IN assertion, the window is not empty so we can't confuse
1425 * more == 0 with more == 64K on a 16 bit machine.
1427 Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM");
1429 memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE);
1430 match_start -= WSIZE;
1431 strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
1433 block_start -= (long) WSIZE;
1435 for (n = 0; n < HASH_SIZE; n++) {
1437 head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
1439 for (n = 0; n < WSIZE; n++) {
1441 prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
1442 /* If n is not on any hash chain, prev[n] is garbage but
1443 * its value will never be used.
1448 /* At this point, more >= 2 */
1450 n = read_buf((char *) window + strstart + lookahead, more);
1451 if (n == 0 || n == (unsigned) EOF) {
1459 /* ===========================================================================
1460 * Flush the current block, with given end-of-file flag.
1461 * IN assertion: strstart is set to the end of the current match.
1463 #define FLUSH_BLOCK(eof) \
1464 flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
1465 (char*)NULL, (long)strstart - block_start, (eof))
1467 /* ===========================================================================
1468 * Same as above, but achieves better compression. We use a lazy
1469 * evaluation for matches: a match is finally adopted only if there is
1470 * no better match at the next window position.
1474 IPos hash_head; /* head of hash chain */
1475 IPos prev_match; /* previous match */
1476 int flush; /* set if current block must be flushed */
1477 int match_available = 0; /* set if previous match exists */
1478 register unsigned match_length = MIN_MATCH - 1; /* length of best match */
1481 extern long isize; /* byte length of input file, for debug only */
1484 /* Process the input block. */
1485 while (lookahead != 0) {
1486 /* Insert the string window[strstart .. strstart+2] in the
1487 * dictionary, and set hash_head to the head of the hash chain:
1489 INSERT_STRING(strstart, hash_head);
1491 /* Find the longest match, discarding those <= prev_length.
1493 prev_length = match_length, prev_match = match_start;
1494 match_length = MIN_MATCH - 1;
1496 if (hash_head != NIL && prev_length < max_lazy_match &&
1497 strstart - hash_head <= MAX_DIST) {
1498 /* To simplify the code, we prevent matches with the string
1499 * of window index 0 (in particular we have to avoid a match
1500 * of the string with itself at the start of the input file).
1502 match_length = longest_match(hash_head);
1503 /* longest_match() sets match_start */
1504 if (match_length > lookahead)
1505 match_length = lookahead;
1507 /* Ignore a length 3 match if it is too distant: */
1508 if (match_length == MIN_MATCH
1509 && strstart - match_start > TOO_FAR) {
1510 /* If prev_match is also MIN_MATCH, match_start is garbage
1511 * but we will ignore the current match anyway.
1516 /* If there was a match at the previous step and the current
1517 * match is not better, output the previous match:
1519 if (prev_length >= MIN_MATCH && match_length <= prev_length) {
1521 check_match(strstart - 1, prev_match, prev_length);
1524 ct_tally(strstart - 1 - prev_match,
1525 prev_length - MIN_MATCH);
1527 /* Insert in hash table all strings up to the end of the match.
1528 * strstart-1 and strstart are already inserted.
1530 lookahead -= prev_length - 1;
1534 INSERT_STRING(strstart, hash_head);
1535 /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1536 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1537 * these bytes are garbage, but it does not matter since the
1538 * next lookahead bytes will always be emitted as literals.
1540 } while (--prev_length != 0);
1541 match_available = 0;
1542 match_length = MIN_MATCH - 1;
1545 FLUSH_BLOCK(0), block_start = strstart;
1547 } else if (match_available) {
1548 /* If there was no match at the previous position, output a
1549 * single literal. If there was a match but the current match
1550 * is longer, truncate the previous match to a single literal.
1552 Tracevv((stderr, "%c", window[strstart - 1]));
1553 if (ct_tally(0, window[strstart - 1])) {
1554 FLUSH_BLOCK(0), block_start = strstart;
1559 /* There is no previous match to compare with, wait for
1560 * the next step to decide.
1562 match_available = 1;
1566 Assert(strstart <= isize && lookahead <= isize, "a bit too far");
1568 /* Make sure that we always have enough lookahead, except
1569 * at the end of the input file. We need MAX_MATCH bytes
1570 * for the next match, plus MIN_MATCH bytes to insert the
1571 * string following the next match.
1573 while (lookahead < MIN_LOOKAHEAD && !eofile)
1576 if (match_available)
1577 ct_tally(0, window[strstart - 1]);
1579 return FLUSH_BLOCK(1); /* eof */
1582 /* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1583 * Copyright (C) 1992-1993 Jean-loup Gailly
1584 * The unzip code was written and put in the public domain by Mark Adler.
1585 * Portions of the lzw code are derived from the public domain 'compress'
1586 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1587 * Ken Turkowski, Dave Mack and Peter Jannesen.
1589 * See the license_msg below and the file COPYING for the software license.
1590 * See the file algorithm.doc for the compression algorithms and file formats.
1593 /* Compress files with zip algorithm and 'compress' interface.
1594 * See usage() and help() functions below for all options.
1596 * file.gz: compressed file with same mode, owner, and utimes
1597 * or stdout with -c option or if stdin used as input.
1598 * If the output file name had to be truncated, the original name is kept
1599 * in the compressed file.
1600 * On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
1602 * Using gz on MSDOS would create too many file name conflicts. For
1603 * example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
1604 * tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
1605 * I also considered 12345678.txt -> 12345txt.gz but this truncates the name
1606 * too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
1608 * For the meaning of all compilation flags, see comments in Makefile.in.
1612 #include <sys/types.h>
1619 # include <sys/time.h>
1628 #ifdef HAVE_UNISTD_H
1629 # include <unistd.h>
1633 # include <dirent.h>
1634 typedef struct dirent dir_type;
1636 # define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
1637 # define DIR_OPT "DIRENT"
1639 # define NLENGTH(dirent) ((dirent)->d_namlen)
1641 # include <sys/dir.h>
1642 typedef struct direct dir_type;
1644 # define DIR_OPT "SYSDIR"
1647 # include <sys/ndir.h>
1648 typedef struct direct dir_type;
1650 # define DIR_OPT "SYSNDIR"
1654 typedef struct direct dir_type;
1656 # define DIR_OPT "NDIR"
1659 # define DIR_OPT "NO_DIR"
1668 # define TIME_OPT "UTIME"
1670 # ifdef HAVE_SYS_UTIME_H
1671 # include <sys/utime.h>
1672 # define TIME_OPT "SYS_UTIME"
1679 # define TIME_OPT ""
1683 # define TIME_OPT "NO_UTIME"
1686 #if !defined(S_ISDIR) && defined(S_IFDIR)
1687 # define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
1689 #if !defined(S_ISREG) && defined(S_IFREG)
1690 # define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
1693 typedef RETSIGTYPE(*sig_type) (int);
1696 # define O_BINARY 0 /* creation mode for open() */
1700 /* Pure BSD system? */
1701 # include <sys/file.h>
1703 # define O_CREAT FCREAT
1706 # define O_EXCL FEXCL
1711 # define S_IRUSR 0400
1714 # define S_IWUSR 0200
1716 #define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
1718 #ifndef MAX_PATH_LEN
1719 # define MAX_PATH_LEN 1024 /* max pathname length */
1728 off_t lseek (int fd, off_t offset, int whence);
1731 /* Separator for file name parts (see shorten_name()) */
1732 #ifdef NO_MULTIPLE_DOTS
1733 # define PART_SEP "-"
1735 # define PART_SEP "."
1738 /* global buffers */
1740 DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1741 DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1742 DECLARE(ush, d_buf, DIST_BUFSIZE);
1743 DECLARE(uch, window, 2L * WSIZE);
1745 DECLARE(ush, tab_prefix, 1L << BITS);
1747 DECLARE(ush, tab_prefix0, 1L << (BITS - 1));
1748 DECLARE(ush, tab_prefix1, 1L << (BITS - 1));
1751 /* local variables */
1753 static int foreground; /* set if program run in foreground */
1754 static int method = DEFLATED; /* compression method */
1755 static int exit_code = OK; /* program exit code */
1756 static int part_nb; /* number of parts in .gz file */
1757 static long time_stamp; /* original time stamp (modification time) */
1758 static long ifile_size; /* input file size, -1 for devices (debug only) */
1759 static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
1760 static int z_len; /* strlen(z_suffix) */
1762 static long bytes_in; /* number of input bytes */
1763 static long bytes_out; /* number of output bytes */
1764 static char ifname[MAX_PATH_LEN]; /* input file name */
1765 static char ofname[MAX_PATH_LEN]; /* output file name */
1766 static int ifd; /* input file descriptor */
1767 static int ofd; /* output file descriptor */
1768 static unsigned insize; /* valid bytes in inbuf */
1769 static unsigned outcnt; /* bytes in output buffer */
1771 /* local functions */
1773 #define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
1775 /* ======================================================================== */
1776 // int main (argc, argv)
1779 int gzip_main(int argc, char **argv)
1784 struct stat statBuf;
1790 /* Parse any options */
1791 while (--argc > 0 && **(++argv) == '-') {
1792 if (*((*argv) + 1) == '\0') {
1795 while (*(++(*argv))) {
1803 /* Ignore 1-9 (compression level) options */
1804 case '1': case '2': case '3': case '4': case '5':
1805 case '6': case '7': case '8': case '9':
1808 exit(gunzip_main(argc, argv));
1819 if (isatty(fileno(stdin)) && fromstdin==1 && force==0)
1820 error_msg_and_die( "data not read from terminal. Use -f to force it.");
1821 if (isatty(fileno(stdout)) && tostdout==1 && force==0)
1822 error_msg_and_die( "data not written to terminal. Use -f to force it.");
1824 foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1826 (void) signal(SIGINT, (sig_type) abort_gzip);
1829 if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
1830 (void) signal(SIGTERM, (sig_type) abort_gzip);
1834 if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
1835 (void) signal(SIGHUP, (sig_type) abort_gzip);
1839 strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
1840 z_len = strlen(z_suffix);
1842 /* Allocate all global buffers (for DYN_ALLOC option) */
1843 ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1844 ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1845 ALLOC(ush, d_buf, DIST_BUFSIZE);
1846 ALLOC(uch, window, 2L * WSIZE);
1848 ALLOC(ush, tab_prefix, 1L << BITS);
1850 ALLOC(ush, tab_prefix0, 1L << (BITS - 1));
1851 ALLOC(ush, tab_prefix1, 1L << (BITS - 1));
1854 if (fromstdin == 1) {
1855 strcpy(ofname, "stdin");
1857 inFileNum = fileno(stdin);
1858 time_stamp = 0; /* time unknown by default */
1859 ifile_size = -1L; /* convention for unknown size */
1861 /* Open up the input file */
1864 strncpy(ifname, *argv, MAX_PATH_LEN);
1866 /* Open input file */
1867 inFileNum = open(ifname, O_RDONLY);
1869 perror_msg_and_die("%s", ifname);
1870 /* Get the time stamp on the input file. */
1871 if (stat(ifname, &statBuf) < 0)
1872 perror_msg_and_die("%s", ifname);
1873 time_stamp = statBuf.st_ctime;
1874 ifile_size = statBuf.st_size;
1878 if (tostdout == 1) {
1879 /* And get to work */
1880 strcpy(ofname, "stdout");
1881 outFileNum = fileno(stdout);
1882 SET_BINARY_MODE(fileno(stdout));
1884 clear_bufs(); /* clear input and output buffers */
1887 /* Actually do the compression/decompression. */
1888 zip(inFileNum, outFileNum);
1892 /* And get to work */
1893 strncpy(ofname, ifname, MAX_PATH_LEN - 4);
1894 strcat(ofname, ".gz");
1897 /* Open output fille */
1898 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
1899 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
1901 outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL);
1904 perror_msg_and_die("%s", ofname);
1905 SET_BINARY_MODE(outFileNum);
1906 /* Set permissions on the file */
1907 fchmod(outFileNum, statBuf.st_mode);
1909 clear_bufs(); /* clear input and output buffers */
1912 /* Actually do the compression/decompression. */
1913 result = zip(inFileNum, outFileNum);
1916 /* Delete the original file */
1918 delFileName = ifname;
1920 delFileName = ofname;
1922 if (unlink(delFileName) < 0)
1923 perror_msg_and_die("%s", delFileName);
1929 /* trees.c -- output deflated data using Huffman coding
1930 * Copyright (C) 1992-1993 Jean-loup Gailly
1931 * This is free software; you can redistribute it and/or modify it under the
1932 * terms of the GNU General Public License, see the file COPYING.
1938 * Encode various sets of source values using variable-length
1939 * binary code trees.
1943 * The PKZIP "deflation" process uses several Huffman trees. The more
1944 * common source values are represented by shorter bit sequences.
1946 * Each code tree is stored in the ZIP file in a compressed form
1947 * which is itself a Huffman encoding of the lengths of
1948 * all the code strings (in ascending order by source values).
1949 * The actual code strings are reconstructed from the lengths in
1950 * the UNZIP process, as described in the "application note"
1951 * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1956 * Data Compression: Techniques and Applications, pp. 53-55.
1957 * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
1960 * Data Compression: Methods and Theory, pp. 49-50.
1961 * Computer Science Press, 1988. ISBN 0-7167-8156-5.
1965 * Addison-Wesley, 1983. ISBN 0-201-06672-6.
1969 * void ct_init (ush *attr, int *methodp)
1970 * Allocate the match buffer, initialize the various tables and save
1971 * the location of the internal file attribute (ascii/binary) and
1972 * method (DEFLATE/STORE)
1974 * void ct_tally (int dist, int lc);
1975 * Save the match info and tally the frequency counts.
1977 * long flush_block (char *buf, ulg stored_len, int eof)
1978 * Determine the best encoding for the current block: dynamic trees,
1979 * static trees or store, and output the encoded block to the zip
1980 * file. Returns the total compressed length for the file so far.
1986 /* ===========================================================================
1991 /* All codes must not exceed MAX_BITS bits */
1993 #define MAX_BL_BITS 7
1994 /* Bit length codes must not exceed MAX_BL_BITS bits */
1996 #define LENGTH_CODES 29
1997 /* number of length codes, not counting the special END_BLOCK code */
1999 #define LITERALS 256
2000 /* number of literal bytes 0..255 */
2002 #define END_BLOCK 256
2003 /* end of block literal code */
2005 #define L_CODES (LITERALS+1+LENGTH_CODES)
2006 /* number of Literal or Length codes, including the END_BLOCK code */
2009 /* number of distance codes */
2012 /* number of codes used to transfer the bit lengths */
2015 local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */
2016 = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
2017 4, 4, 5, 5, 5, 5, 0 };
2019 local int near extra_dbits[D_CODES] /* extra bits for each distance code */
2020 = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
2021 10, 10, 11, 11, 12, 12, 13, 13 };
2023 local int near extra_blbits[BL_CODES] /* extra bits for each bit length code */
2024 = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
2026 #define STORED_BLOCK 0
2027 #define STATIC_TREES 1
2029 /* The three kinds of block type */
2033 # define LIT_BUFSIZE 0x2000
2036 # define LIT_BUFSIZE 0x4000
2038 # define LIT_BUFSIZE 0x8000
2042 #ifndef DIST_BUFSIZE
2043 # define DIST_BUFSIZE LIT_BUFSIZE
2045 /* Sizes of match buffers for literals/lengths and distances. There are
2046 * 4 reasons for limiting LIT_BUFSIZE to 64K:
2047 * - frequencies can be kept in 16 bit counters
2048 * - if compression is not successful for the first block, all input data is
2049 * still in the window so we can still emit a stored block even when input
2050 * comes from standard input. (This can also be done for all blocks if
2051 * LIT_BUFSIZE is not greater than 32K.)
2052 * - if compression is not successful for a file smaller than 64K, we can
2053 * even emit a stored file instead of a stored block (saving 5 bytes).
2054 * - creating new Huffman trees less frequently may not provide fast
2055 * adaptation to changes in the input data statistics. (Take for
2056 * example a binary file with poorly compressible code followed by
2057 * a highly compressible string table.) Smaller buffer sizes give
2058 * fast adaptation but have of course the overhead of transmitting trees
2060 * - I can't count above 4
2061 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
2062 * memory at the expense of compression). Some optimizations would be possible
2063 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
2065 #if LIT_BUFSIZE > INBUFSIZ
2066 error cannot overlay l_buf and inbuf
2069 /* repeat previous bit length 3-6 times (2 bits of repeat count) */
2070 #define REPZ_3_10 17
2071 /* repeat a zero length 3-10 times (3 bits of repeat count) */
2072 #define REPZ_11_138 18
2073 /* repeat a zero length 11-138 times (7 bits of repeat count) *//* ===========================================================================
2075 *//* Data structure describing a single value and its code string. */ typedef struct ct_data {
2077 ush freq; /* frequency count */
2078 ush code; /* bit string */
2081 ush dad; /* father node in Huffman tree */
2082 ush len; /* length of bit string */
2086 #define Freq fc.freq
2087 #define Code fc.code
2091 #define HEAP_SIZE (2*L_CODES+1)
2092 /* maximum heap size */
2094 local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */
2095 local ct_data near dyn_dtree[2 * D_CODES + 1]; /* distance tree */
2097 local ct_data near static_ltree[L_CODES + 2];
2099 /* The static literal tree. Since the bit lengths are imposed, there is no
2100 * need for the L_CODES extra codes used during heap construction. However
2101 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
2105 local ct_data near static_dtree[D_CODES];
2107 /* The static distance tree. (Actually a trivial tree since all codes use
2111 local ct_data near bl_tree[2 * BL_CODES + 1];
2113 /* Huffman tree for the bit lengths */
2115 typedef struct tree_desc {
2116 ct_data near *dyn_tree; /* the dynamic tree */
2117 ct_data near *static_tree; /* corresponding static tree or NULL */
2118 int near *extra_bits; /* extra bits for each code or NULL */
2119 int extra_base; /* base index for extra_bits */
2120 int elems; /* max number of elements in the tree */
2121 int max_length; /* max bit length for the codes */
2122 int max_code; /* largest code with non zero frequency */
2125 local tree_desc near l_desc =
2126 { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES,
2129 local tree_desc near d_desc =
2130 { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 };
2132 local tree_desc near bl_desc =
2133 { bl_tree, (ct_data near *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS,
2137 local ush near bl_count[MAX_BITS + 1];
2139 /* number of codes at each bit length for an optimal tree */
2141 local uch near bl_order[BL_CODES]
2142 = { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
2144 /* The lengths of the bit length codes are sent in order of decreasing
2145 * probability, to avoid transmitting the lengths for unused bit length codes.
2148 local int near heap[2 * L_CODES + 1]; /* heap used to build the Huffman trees */
2149 local int heap_len; /* number of elements in the heap */
2150 local int heap_max; /* element of largest frequency */
2152 /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
2153 * The same heap array is used to build all trees.
2156 local uch near depth[2 * L_CODES + 1];
2158 /* Depth of each subtree used as tie breaker for trees of equal frequency */
2160 local uch length_code[MAX_MATCH - MIN_MATCH + 1];
2162 /* length code for each normalized match length (0 == MIN_MATCH) */
2164 local uch dist_code[512];
2166 /* distance codes. The first 256 values correspond to the distances
2167 * 3 .. 258, the last 256 values correspond to the top 8 bits of
2168 * the 15 bit distances.
2171 local int near base_length[LENGTH_CODES];
2173 /* First normalized length for each code (0 = MIN_MATCH) */
2175 local int near base_dist[D_CODES];
2177 /* First normalized distance for each code (0 = distance of 1) */
2180 /* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */
2182 /* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
2184 local uch near flag_buf[(LIT_BUFSIZE / 8)];
2186 /* flag_buf is a bit array distinguishing literals from lengths in
2187 * l_buf, thus indicating the presence or absence of a distance.
2190 local unsigned last_lit; /* running index in l_buf */
2191 local unsigned last_dist; /* running index in d_buf */
2192 local unsigned last_flags; /* running index in flag_buf */
2193 local uch flags; /* current flags not yet saved in flag_buf */
2194 local uch flag_bit; /* current bit used in flags */
2196 /* bits are filled in flags starting at bit 0 (least significant).
2197 * Note: these flags are overkill in the current code since we don't
2198 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
2201 local ulg opt_len; /* bit length of current block with optimal trees */
2202 local ulg static_len; /* bit length of current block with static trees */
2204 local ulg compressed_len; /* total bit length of compressed file */
2206 local ulg input_len; /* total byte length of input file */
2208 /* input_len is for debugging only since we can get it by other means. */
2210 ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
2211 int *file_method; /* pointer to DEFLATE or STORE */
2214 extern ulg bits_sent; /* bit length of the compressed data */
2215 extern long isize; /* byte length of input file */
2218 extern long block_start; /* window offset of current block */
2219 extern unsigned near strstart; /* window offset of current string */
2221 /* ===========================================================================
2222 * Local (static) routines in this file.
2225 local void init_block (void);
2226 local void pqdownheap (ct_data near * tree, int k);
2227 local void gen_bitlen (tree_desc near * desc);
2228 local void gen_codes (ct_data near * tree, int max_code);
2229 local void build_tree (tree_desc near * desc);
2230 local void scan_tree (ct_data near * tree, int max_code);
2231 local void send_tree (ct_data near * tree, int max_code);
2232 local int build_bl_tree (void);
2233 local void send_all_trees (int lcodes, int dcodes, int blcodes);
2234 local void compress_block (ct_data near * ltree, ct_data near * dtree);
2235 local void set_file_type (void);
2239 # define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
2240 /* Send a code of the given tree. c and tree must not have side effects */
2243 # define send_code(c, tree) \
2244 { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
2245 send_bits(tree[c].Code, tree[c].Len); }
2248 #define d_code(dist) \
2249 ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
2250 /* Mapping from a distance to a distance code. dist is the distance - 1 and
2251 * must not have side effects. dist_code[256] and dist_code[257] are never
2255 /* the arguments must not have side effects */
2257 /* ===========================================================================
2258 * Allocate the match buffer, initialize the various tables and save the
2259 * location of the internal file attribute (ascii/binary) and method
2262 void ct_init(attr, methodp)
2263 ush *attr; /* pointer to internal file attribute */
2264 int *methodp; /* pointer to compression method */
2266 int n; /* iterates over tree elements */
2267 int bits; /* bit counter */
2268 int length; /* length value */
2269 int code; /* code value */
2270 int dist; /* distance index */
2273 file_method = methodp;
2274 compressed_len = input_len = 0L;
2276 if (static_dtree[0].Len != 0)
2277 return; /* ct_init already called */
2279 /* Initialize the mapping length (0..255) -> length code (0..28) */
2281 for (code = 0; code < LENGTH_CODES - 1; code++) {
2282 base_length[code] = length;
2283 for (n = 0; n < (1 << extra_lbits[code]); n++) {
2284 length_code[length++] = (uch) code;
2287 Assert(length == 256, "ct_init: length != 256");
2288 /* Note that the length 255 (match length 258) can be represented
2289 * in two different ways: code 284 + 5 bits or code 285, so we
2290 * overwrite length_code[255] to use the best encoding:
2292 length_code[length - 1] = (uch) code;
2294 /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
2296 for (code = 0; code < 16; code++) {
2297 base_dist[code] = dist;
2298 for (n = 0; n < (1 << extra_dbits[code]); n++) {
2299 dist_code[dist++] = (uch) code;
2302 Assert(dist == 256, "ct_init: dist != 256");
2303 dist >>= 7; /* from now on, all distances are divided by 128 */
2304 for (; code < D_CODES; code++) {
2305 base_dist[code] = dist << 7;
2306 for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
2307 dist_code[256 + dist++] = (uch) code;
2310 Assert(dist == 256, "ct_init: 256+dist != 512");
2312 /* Construct the codes of the static literal tree */
2313 for (bits = 0; bits <= MAX_BITS; bits++)
2317 static_ltree[n++].Len = 8, bl_count[8]++;
2319 static_ltree[n++].Len = 9, bl_count[9]++;
2321 static_ltree[n++].Len = 7, bl_count[7]++;
2323 static_ltree[n++].Len = 8, bl_count[8]++;
2324 /* Codes 286 and 287 do not exist, but we must include them in the
2325 * tree construction to get a canonical Huffman tree (longest code
2328 gen_codes((ct_data near *) static_ltree, L_CODES + 1);
2330 /* The static distance tree is trivial: */
2331 for (n = 0; n < D_CODES; n++) {
2332 static_dtree[n].Len = 5;
2333 static_dtree[n].Code = bi_reverse(n, 5);
2336 /* Initialize the first block of the first file: */
2340 /* ===========================================================================
2341 * Initialize a new block.
2343 local void init_block()
2345 int n; /* iterates over tree elements */
2347 /* Initialize the trees. */
2348 for (n = 0; n < L_CODES; n++)
2349 dyn_ltree[n].Freq = 0;
2350 for (n = 0; n < D_CODES; n++)
2351 dyn_dtree[n].Freq = 0;
2352 for (n = 0; n < BL_CODES; n++)
2353 bl_tree[n].Freq = 0;
2355 dyn_ltree[END_BLOCK].Freq = 1;
2356 opt_len = static_len = 0L;
2357 last_lit = last_dist = last_flags = 0;
2363 /* Index within the heap array of least frequent node in the Huffman tree */
2366 /* ===========================================================================
2367 * Remove the smallest element from the heap and recreate the heap with
2368 * one less element. Updates heap and heap_len.
2370 #define pqremove(tree, top) \
2372 top = heap[SMALLEST]; \
2373 heap[SMALLEST] = heap[heap_len--]; \
2374 pqdownheap(tree, SMALLEST); \
2377 /* ===========================================================================
2378 * Compares to subtrees, using the tree depth as tie breaker when
2379 * the subtrees have equal frequency. This minimizes the worst case length.
2381 #define smaller(tree, n, m) \
2382 (tree[n].Freq < tree[m].Freq || \
2383 (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
2385 /* ===========================================================================
2386 * Restore the heap property by moving down the tree starting at node k,
2387 * exchanging a node with the smallest of its two sons if necessary, stopping
2388 * when the heap property is re-established (each father smaller than its
2391 local void pqdownheap(tree, k)
2392 ct_data near *tree; /* the tree to restore */
2393 int k; /* node to move down */
2396 int j = k << 1; /* left son of k */
2398 while (j <= heap_len) {
2399 /* Set j to the smallest of the two sons: */
2400 if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
2403 /* Exit if v is smaller than both sons */
2404 if (smaller(tree, v, heap[j]))
2407 /* Exchange v with the smallest son */
2411 /* And continue down the tree, setting j to the left son of k */
2417 /* ===========================================================================
2418 * Compute the optimal bit lengths for a tree and update the total bit length
2419 * for the current block.
2420 * IN assertion: the fields freq and dad are set, heap[heap_max] and
2421 * above are the tree nodes sorted by increasing frequency.
2422 * OUT assertions: the field len is set to the optimal bit length, the
2423 * array bl_count contains the frequencies for each bit length.
2424 * The length opt_len is updated; static_len is also updated if stree is
2427 local void gen_bitlen(desc)
2428 tree_desc near *desc; /* the tree descriptor */
2430 ct_data near *tree = desc->dyn_tree;
2431 int near *extra = desc->extra_bits;
2432 int base = desc->extra_base;
2433 int max_code = desc->max_code;
2434 int max_length = desc->max_length;
2435 ct_data near *stree = desc->static_tree;
2436 int h; /* heap index */
2437 int n, m; /* iterate over the tree elements */
2438 int bits; /* bit length */
2439 int xbits; /* extra bits */
2440 ush f; /* frequency */
2441 int overflow = 0; /* number of elements with bit length too large */
2443 for (bits = 0; bits <= MAX_BITS; bits++)
2446 /* In a first pass, compute the optimal bit lengths (which may
2447 * overflow in the case of the bit length tree).
2449 tree[heap[heap_max]].Len = 0; /* root of the heap */
2451 for (h = heap_max + 1; h < HEAP_SIZE; h++) {
2453 bits = tree[tree[n].Dad].Len + 1;
2454 if (bits > max_length)
2455 bits = max_length, overflow++;
2456 tree[n].Len = (ush) bits;
2457 /* We overwrite tree[n].Dad which is no longer needed */
2460 continue; /* not a leaf node */
2465 xbits = extra[n - base];
2467 opt_len += (ulg) f *(bits + xbits);
2470 static_len += (ulg) f *(stree[n].Len + xbits);
2475 Trace((stderr, "\nbit length overflow\n"));
2476 /* This happens for example on obj2 and pic of the Calgary corpus */
2478 /* Find the first bit length which could increase: */
2480 bits = max_length - 1;
2481 while (bl_count[bits] == 0)
2483 bl_count[bits]--; /* move one leaf down the tree */
2484 bl_count[bits + 1] += 2; /* move one overflow item as its brother */
2485 bl_count[max_length]--;
2486 /* The brother of the overflow item also moves one step up,
2487 * but this does not affect bl_count[max_length]
2490 } while (overflow > 0);
2492 /* Now recompute all bit lengths, scanning in increasing frequency.
2493 * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
2494 * lengths instead of fixing only the wrong ones. This idea is taken
2495 * from 'ar' written by Haruhiko Okumura.)
2497 for (bits = max_length; bits != 0; bits--) {
2503 if (tree[m].Len != (unsigned) bits) {
2505 (stderr, "code %d bits %d->%d\n", m, tree[m].Len,
2509 (long) tree[m].Len) * (long) tree[m].Freq;
2510 tree[m].Len = (ush) bits;
2517 /* ===========================================================================
2518 * Generate the codes for a given tree and bit counts (which need not be
2520 * IN assertion: the array bl_count contains the bit length statistics for
2521 * the given tree and the field len is set for all tree elements.
2522 * OUT assertion: the field code is set for all tree elements of non
2525 local void gen_codes(tree, max_code)
2526 ct_data near *tree; /* the tree to decorate */
2527 int max_code; /* largest code with non zero frequency */
2529 ush next_code[MAX_BITS + 1]; /* next code value for each bit length */
2530 ush code = 0; /* running code value */
2531 int bits; /* bit index */
2532 int n; /* code index */
2534 /* The distribution counts are first used to generate the code values
2535 * without bit reversal.
2537 for (bits = 1; bits <= MAX_BITS; bits++) {
2538 next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
2540 /* Check that the bit counts in bl_count are consistent. The last code
2543 Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
2544 "inconsistent bit counts");
2545 Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
2547 for (n = 0; n <= max_code; n++) {
2548 int len = tree[n].Len;
2552 /* Now reverse the bits */
2553 tree[n].Code = bi_reverse(next_code[len]++, len);
2555 Tracec(tree != static_ltree,
2556 (stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
2557 (isgraph(n) ? n : ' '), len, tree[n].Code,
2558 next_code[len] - 1));
2562 /* ===========================================================================
2563 * Construct one Huffman tree and assigns the code bit strings and lengths.
2564 * Update the total bit length for the current block.
2565 * IN assertion: the field freq is set for all tree elements.
2566 * OUT assertions: the fields len and code are set to the optimal bit length
2567 * and corresponding code. The length opt_len is updated; static_len is
2568 * also updated if stree is not null. The field max_code is set.
2570 local void build_tree(desc)
2571 tree_desc near *desc; /* the tree descriptor */
2573 ct_data near *tree = desc->dyn_tree;
2574 ct_data near *stree = desc->static_tree;
2575 int elems = desc->elems;
2576 int n, m; /* iterate over heap elements */
2577 int max_code = -1; /* largest code with non zero frequency */
2578 int node = elems; /* next internal node of the tree */
2580 /* Construct the initial heap, with least frequent element in
2581 * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
2582 * heap[0] is not used.
2584 heap_len = 0, heap_max = HEAP_SIZE;
2586 for (n = 0; n < elems; n++) {
2587 if (tree[n].Freq != 0) {
2588 heap[++heap_len] = max_code = n;
2595 /* The pkzip format requires that at least one distance code exists,
2596 * and that at least one bit should be sent even if there is only one
2597 * possible code. So to avoid special checks later on we force at least
2598 * two codes of non zero frequency.
2600 while (heap_len < 2) {
2601 int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
2607 static_len -= stree[new].Len;
2608 /* new is 0 or 1 so it does not have extra bits */
2610 desc->max_code = max_code;
2612 /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
2613 * establish sub-heaps of increasing lengths:
2615 for (n = heap_len / 2; n >= 1; n--)
2616 pqdownheap(tree, n);
2618 /* Construct the Huffman tree by repeatedly combining the least two
2622 pqremove(tree, n); /* n = node of least frequency */
2623 m = heap[SMALLEST]; /* m = node of next least frequency */
2625 heap[--heap_max] = n; /* keep the nodes sorted by frequency */
2626 heap[--heap_max] = m;
2628 /* Create a new node father of n and m */
2629 tree[node].Freq = tree[n].Freq + tree[m].Freq;
2630 depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
2631 tree[n].Dad = tree[m].Dad = (ush) node;
2633 if (tree == bl_tree) {
2634 fprintf(stderr, "\nnode %d(%d), sons %d(%d) %d(%d)",
2635 node, tree[node].Freq, n, tree[n].Freq, m,
2639 /* and insert the new node in the heap */
2640 heap[SMALLEST] = node++;
2641 pqdownheap(tree, SMALLEST);
2643 } while (heap_len >= 2);
2645 heap[--heap_max] = heap[SMALLEST];
2647 /* At this point, the fields freq and dad are set. We can now
2648 * generate the bit lengths.
2650 gen_bitlen((tree_desc near *) desc);
2652 /* The field len is now set, we can generate the bit codes */
2653 gen_codes((ct_data near *) tree, max_code);
2656 /* ===========================================================================
2657 * Scan a literal or distance tree to determine the frequencies of the codes
2658 * in the bit length tree. Updates opt_len to take into account the repeat
2659 * counts. (The contribution of the bit length codes will be added later
2660 * during the construction of bl_tree.)
2662 local void scan_tree(tree, max_code)
2663 ct_data near *tree; /* the tree to be scanned */
2664 int max_code; /* and its largest code of non zero frequency */
2666 int n; /* iterates over all tree elements */
2667 int prevlen = -1; /* last emitted length */
2668 int curlen; /* length of current code */
2669 int nextlen = tree[0].Len; /* length of next code */
2670 int count = 0; /* repeat count of the current code */
2671 int max_count = 7; /* max repeat count */
2672 int min_count = 4; /* min repeat count */
2675 max_count = 138, min_count = 3;
2676 tree[max_code + 1].Len = (ush) 0xffff; /* guard */
2678 for (n = 0; n <= max_code; n++) {
2680 nextlen = tree[n + 1].Len;
2681 if (++count < max_count && curlen == nextlen) {
2683 } else if (count < min_count) {
2684 bl_tree[curlen].Freq += count;
2685 } else if (curlen != 0) {
2686 if (curlen != prevlen)
2687 bl_tree[curlen].Freq++;
2688 bl_tree[REP_3_6].Freq++;
2689 } else if (count <= 10) {
2690 bl_tree[REPZ_3_10].Freq++;
2692 bl_tree[REPZ_11_138].Freq++;
2697 max_count = 138, min_count = 3;
2698 } else if (curlen == nextlen) {
2699 max_count = 6, min_count = 3;
2701 max_count = 7, min_count = 4;
2706 /* ===========================================================================
2707 * Send a literal or distance tree in compressed form, using the codes in
2710 local void send_tree(tree, max_code)
2711 ct_data near *tree; /* the tree to be scanned */
2712 int max_code; /* and its largest code of non zero frequency */
2714 int n; /* iterates over all tree elements */
2715 int prevlen = -1; /* last emitted length */
2716 int curlen; /* length of current code */
2717 int nextlen = tree[0].Len; /* length of next code */
2718 int count = 0; /* repeat count of the current code */
2719 int max_count = 7; /* max repeat count */
2720 int min_count = 4; /* min repeat count */
2722 /* tree[max_code+1].Len = -1; *//* guard already set */
2724 max_count = 138, min_count = 3;
2726 for (n = 0; n <= max_code; n++) {
2728 nextlen = tree[n + 1].Len;
2729 if (++count < max_count && curlen == nextlen) {
2731 } else if (count < min_count) {
2733 send_code(curlen, bl_tree);
2734 } while (--count != 0);
2736 } else if (curlen != 0) {
2737 if (curlen != prevlen) {
2738 send_code(curlen, bl_tree);
2741 Assert(count >= 3 && count <= 6, " 3_6?");
2742 send_code(REP_3_6, bl_tree);
2743 send_bits(count - 3, 2);
2745 } else if (count <= 10) {
2746 send_code(REPZ_3_10, bl_tree);
2747 send_bits(count - 3, 3);
2750 send_code(REPZ_11_138, bl_tree);
2751 send_bits(count - 11, 7);
2756 max_count = 138, min_count = 3;
2757 } else if (curlen == nextlen) {
2758 max_count = 6, min_count = 3;
2760 max_count = 7, min_count = 4;
2765 /* ===========================================================================
2766 * Construct the Huffman tree for the bit lengths and return the index in
2767 * bl_order of the last bit length code to send.
2769 local int build_bl_tree()
2771 int max_blindex; /* index of last bit length code of non zero freq */
2773 /* Determine the bit length frequencies for literal and distance trees */
2774 scan_tree((ct_data near *) dyn_ltree, l_desc.max_code);
2775 scan_tree((ct_data near *) dyn_dtree, d_desc.max_code);
2777 /* Build the bit length tree: */
2778 build_tree((tree_desc near *) (&bl_desc));
2779 /* opt_len now includes the length of the tree representations, except
2780 * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2783 /* Determine the number of bit length codes to send. The pkzip format
2784 * requires that at least 4 bit length codes be sent. (appnote.txt says
2785 * 3 but the actual value used is 4.)
2787 for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
2788 if (bl_tree[bl_order[max_blindex]].Len != 0)
2791 /* Update opt_len to include the bit length tree and counts */
2792 opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
2794 (stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len,
2800 /* ===========================================================================
2801 * Send the header for a block using dynamic Huffman trees: the counts, the
2802 * lengths of the bit length codes, the literal tree and the distance tree.
2803 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2805 local void send_all_trees(lcodes, dcodes, blcodes)
2806 int lcodes, dcodes, blcodes; /* number of codes for each tree */
2808 int rank; /* index in bl_order */
2810 Assert(lcodes >= 257 && dcodes >= 1
2811 && blcodes >= 4, "not enough codes");
2812 Assert(lcodes <= L_CODES && dcodes <= D_CODES
2813 && blcodes <= BL_CODES, "too many codes");
2814 Tracev((stderr, "\nbl counts: "));
2815 send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */
2816 send_bits(dcodes - 1, 5);
2817 send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */
2818 for (rank = 0; rank < blcodes; rank++) {
2819 Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2820 send_bits(bl_tree[bl_order[rank]].Len, 3);
2822 Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
2824 send_tree((ct_data near *) dyn_ltree, lcodes - 1); /* send the literal tree */
2825 Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
2827 send_tree((ct_data near *) dyn_dtree, dcodes - 1); /* send the distance tree */
2828 Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
2831 /* ===========================================================================
2832 * Determine the best encoding for the current block: dynamic trees, static
2833 * trees or store, and output the encoded block to the zip file. This function
2834 * returns the total compressed length for the file so far.
2836 ulg flush_block(buf, stored_len, eof)
2837 char *buf; /* input block, or NULL if too old */
2838 ulg stored_len; /* length of input block */
2839 int eof; /* true if this is the last block for a file */
2841 ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
2842 int max_blindex; /* index of last bit length code of non zero freq */
2844 flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
2846 /* Check if the file is ascii or binary */
2847 if (*file_type == (ush) UNKNOWN)
2850 /* Construct the literal and distance trees */
2851 build_tree((tree_desc near *) (&l_desc));
2852 Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
2854 build_tree((tree_desc near *) (&d_desc));
2856 (stderr, "\ndist data: dyn %ld, stat %ld", opt_len,
2858 /* At this point, opt_len and static_len are the total bit lengths of
2859 * the compressed block data, excluding the tree representations.
2862 /* Build the bit length tree for the above two trees, and get the index
2863 * in bl_order of the last bit length code to send.
2865 max_blindex = build_bl_tree();
2867 /* Determine the best encoding. Compute first the block length in bytes */
2868 opt_lenb = (opt_len + 3 + 7) >> 3;
2869 static_lenb = (static_len + 3 + 7) >> 3;
2870 input_len += stored_len; /* for debugging only */
2874 "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2875 opt_lenb, opt_len, static_lenb, static_len, stored_len,
2876 last_lit, last_dist));
2878 if (static_lenb <= opt_lenb)
2879 opt_lenb = static_lenb;
2881 /* If compression failed and this is the first and last block,
2882 * and if the zip file can be seeked (to rewrite the local header),
2883 * the whole file is transformed into a stored file:
2887 if (stored_len <= opt_lenb && eof && compressed_len == 0L
2890 /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2891 if (buf == (char *) 0)
2892 error_msg("block vanished");
2894 copy_block(buf, (unsigned) stored_len, 0); /* without header */
2895 compressed_len = stored_len << 3;
2896 *file_method = STORED;
2900 } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
2901 /* 4: two words for the lengths */
2903 /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2904 * Otherwise we can't have processed more than WSIZE input bytes since
2905 * the last block flush, because compression would have been
2906 * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2907 * transform a block into a stored block.
2909 send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */
2910 compressed_len = (compressed_len + 3 + 7) & ~7L;
2911 compressed_len += (stored_len + 4) << 3;
2913 copy_block(buf, (unsigned) stored_len, 1); /* with header */
2917 } else if (static_lenb == opt_lenb) {
2919 send_bits((STATIC_TREES << 1) + eof, 3);
2920 compress_block((ct_data near *) static_ltree,
2921 (ct_data near *) static_dtree);
2922 compressed_len += 3 + static_len;
2924 send_bits((DYN_TREES << 1) + eof, 3);
2925 send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1,
2927 compress_block((ct_data near *) dyn_ltree,
2928 (ct_data near *) dyn_dtree);
2929 compressed_len += 3 + opt_len;
2931 Assert(compressed_len == bits_sent, "bad compressed size");
2935 Assert(input_len == isize, "bad input size");
2937 compressed_len += 7; /* align on byte boundary */
2939 Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
2940 compressed_len - 7 * eof));
2942 return compressed_len >> 3;
2945 /* ===========================================================================
2946 * Save the match info and tally the frequency counts. Return true if
2947 * the current block must be flushed.
2949 int ct_tally(dist, lc)
2950 int dist; /* distance of matched string */
2951 int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
2953 l_buf[last_lit++] = (uch) lc;
2955 /* lc is the unmatched char */
2956 dyn_ltree[lc].Freq++;
2958 /* Here, lc is the match length - MIN_MATCH */
2959 dist--; /* dist = match distance - 1 */
2960 Assert((ush) dist < (ush) MAX_DIST &&
2961 (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) &&
2962 (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match");
2964 dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
2965 dyn_dtree[d_code(dist)].Freq++;
2967 d_buf[last_dist++] = (ush) dist;
2972 /* Output the flags if they fill a byte: */
2973 if ((last_lit & 7) == 0) {
2974 flag_buf[last_flags++] = flags;
2975 flags = 0, flag_bit = 1;
2977 /* Try to guess if it is profitable to stop the current block here */
2978 if ((last_lit & 0xfff) == 0) {
2979 /* Compute an upper bound for the compressed length */
2980 ulg out_length = (ulg) last_lit * 8L;
2981 ulg in_length = (ulg) strstart - block_start;
2984 for (dcode = 0; dcode < D_CODES; dcode++) {
2986 (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
2991 "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
2992 last_lit, last_dist, in_length, out_length,
2993 100L - out_length * 100L / in_length));
2994 if (last_dist < last_lit / 2 && out_length < in_length / 2)
2997 return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE);
2998 /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
2999 * on 16 bit machines and because stored blocks are restricted to
3004 /* ===========================================================================
3005 * Send the block data compressed using the given Huffman trees
3007 local void compress_block(ltree, dtree)
3008 ct_data near *ltree; /* literal tree */
3009 ct_data near *dtree; /* distance tree */
3011 unsigned dist; /* distance of matched string */
3012 int lc; /* match length or unmatched char (if dist == 0) */
3013 unsigned lx = 0; /* running index in l_buf */
3014 unsigned dx = 0; /* running index in d_buf */
3015 unsigned fx = 0; /* running index in flag_buf */
3016 uch flag = 0; /* current flags */
3017 unsigned code; /* the code to send */
3018 int extra; /* number of extra bits to send */
3023 flag = flag_buf[fx++];
3025 if ((flag & 1) == 0) {
3026 send_code(lc, ltree); /* send a literal byte */
3027 Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
3029 /* Here, lc is the match length - MIN_MATCH */
3030 code = length_code[lc];
3031 send_code(code + LITERALS + 1, ltree); /* send the length code */
3032 extra = extra_lbits[code];
3034 lc -= base_length[code];
3035 send_bits(lc, extra); /* send the extra length bits */
3038 /* Here, dist is the match distance - 1 */
3039 code = d_code(dist);
3040 Assert(code < D_CODES, "bad d_code");
3042 send_code(code, dtree); /* send the distance code */
3043 extra = extra_dbits[code];
3045 dist -= base_dist[code];
3046 send_bits(dist, extra); /* send the extra distance bits */
3048 } /* literal or match pair ? */
3050 } while (lx < last_lit);
3052 send_code(END_BLOCK, ltree);
3055 /* ===========================================================================
3056 * Set the file type to ASCII or BINARY, using a crude approximation:
3057 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
3058 * IN assertion: the fields freq of dyn_ltree are set and the total of all
3059 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
3061 local void set_file_type()
3064 unsigned ascii_freq = 0;
3065 unsigned bin_freq = 0;
3068 bin_freq += dyn_ltree[n++].Freq;
3070 ascii_freq += dyn_ltree[n++].Freq;
3071 while (n < LITERALS)
3072 bin_freq += dyn_ltree[n++].Freq;
3073 *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
3074 if (*file_type == BINARY && translate_eol) {
3075 error_msg("-l used on binary file");
3079 /* util.c -- utility functions for gzip support
3080 * Copyright (C) 1992-1993 Jean-loup Gailly
3081 * This is free software; you can redistribute it and/or modify it under the
3082 * terms of the GNU General Public License, see the file COPYING.
3087 #include <sys/types.h>
3089 #ifdef HAVE_UNISTD_H
3090 # include <unistd.h>
3096 /* ===========================================================================
3097 * Copy input to output unchanged: zcat == cat with --force.
3098 * IN assertion: insize bytes have already been read in inbuf.
3101 int in, out; /* input and output file descriptors */
3104 while (insize != 0 && (int) insize != EOF) {
3105 write_buf(out, (char *) inbuf, insize);
3106 bytes_out += insize;
3107 insize = read(in, (char *) inbuf, INBUFSIZ);
3109 if ((int) insize == EOF && errno != 0) {
3112 bytes_in = bytes_out;
3116 /* ========================================================================
3117 * Put string s in lower case, return s.
3124 for (t = s; *t; t++)
3129 #if defined(NO_STRING_H) && !defined(STDC_HEADERS)
3131 /* Provide missing strspn and strcspn functions. */
3133 int strspn (const char *s, const char *accept);
3134 int strcspn (const char *s, const char *reject);
3136 /* ========================================================================
3137 * Return the length of the maximum initial segment
3138 * of s which contains only characters in accept.
3140 int strspn(s, accept)
3144 register const char *p;
3145 register const char *a;
3146 register int count = 0;
3148 for (p = s; *p != '\0'; ++p) {
3149 for (a = accept; *a != '\0'; ++a) {
3160 /* ========================================================================
3161 * Return the length of the maximum inital segment of s
3162 * which contains no characters from reject.
3164 int strcspn(s, reject)
3168 register int count = 0;
3170 while (*s != '\0') {
3171 if (strchr(reject, *s++) != NULL)
3178 #endif /* NO_STRING_H */
3180 /* ========================================================================
3181 * Add an environment variable (if any) before argv, and update argc.
3182 * Return the expanded environment variable to be freed later, or NULL
3183 * if no options were added to argv.
3185 #define SEPARATOR " \t" /* separators in env variable */
3187 char *add_envopt(argcp, argvp, env)
3188 int *argcp; /* pointer to argc */
3189 char ***argvp; /* pointer to argv */
3190 char *env; /* name of environment variable */
3192 char *p; /* running pointer through env variable */
3193 char **oargv; /* runs through old argv array */
3194 char **nargv; /* runs through new argv array */
3195 int oargc = *argcp; /* old argc */
3196 int nargc = 0; /* number of arguments in env variable */
3198 env = (char *) getenv(env);
3202 p = (char *) xmalloc(strlen(env) + 1);
3203 env = strcpy(p, env); /* keep env variable intact */
3205 for (p = env; *p; nargc++) { /* move through env */
3206 p += strspn(p, SEPARATOR); /* skip leading separators */
3210 p += strcspn(p, SEPARATOR); /* find end of word */
3212 *p++ = '\0'; /* mark it */
3219 /* Allocate the new argv array, with an extra element just in case
3220 * the original arg list did not end with a NULL.
3222 nargv = (char **) calloc(*argcp + 1, sizeof(char *));
3225 error_msg(memory_exhausted);
3229 /* Copy the program name first */
3231 error_msg("argc<=0");
3232 *(nargv++) = *(oargv++);
3234 /* Then copy the environment args */
3235 for (p = env; nargc > 0; nargc--) {
3236 p += strspn(p, SEPARATOR); /* skip separators */
3237 *(nargv++) = p; /* store start */
3238 while (*p++); /* skip over word */
3241 /* Finally copy the old args and add a NULL (usual convention) */
3243 *(nargv++) = *(oargv++);
3248 /* ========================================================================
3249 * Display compression ratio on the given stream on 6 characters.
3251 void display_ratio(num, den, file)
3256 long ratio; /* 1000 times the compression ratio */
3259 ratio = 0; /* no compression */
3260 } else if (den < 2147483L) { /* (2**31 -1)/1000 */
3261 ratio = 1000L * num / den;
3263 ratio = num / (den / 1000L);
3271 fprintf(file, "%2ld.%1ld%%", ratio / 10L, ratio % 10L);
3275 /* zip.c -- compress files to the gzip or pkzip format
3276 * Copyright (C) 1992-1993 Jean-loup Gailly
3277 * This is free software; you can redistribute it and/or modify it under the
3278 * terms of the GNU General Public License, see the file COPYING.
3282 #include <sys/types.h>
3284 #ifdef HAVE_UNISTD_H
3285 # include <unistd.h>
3291 local ulg crc; /* crc on uncompressed file data */
3292 long header_bytes; /* number of bytes in gzip header */
3294 /* ===========================================================================
3295 * Deflate in to out.
3296 * IN assertions: the input and output buffers are cleared.
3297 * The variables time_stamp and save_orig_name are initialized.
3300 int in, out; /* input and output file descriptors */
3302 uch flags = 0; /* general purpose bit flags */
3303 ush attr = 0; /* ascii/binary flag */
3304 ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
3310 /* Write the header to the gzip file. See algorithm.doc for the format */
3314 put_byte(GZIP_MAGIC[0]); /* magic header */
3315 put_byte(GZIP_MAGIC[1]);
3316 put_byte(DEFLATED); /* compression method */
3318 put_byte(flags); /* general flags */
3319 put_long(time_stamp);
3321 /* Write deflated file to zip file */
3325 ct_init(&attr, &method);
3326 lm_init(&deflate_flags);
3328 put_byte((uch) deflate_flags); /* extra flags */
3329 put_byte(OS_CODE); /* OS identifier */
3331 header_bytes = (long) outcnt;
3335 /* Write the crc and uncompressed size */
3338 header_bytes += 2 * sizeof(long);
3345 /* ===========================================================================
3346 * Read a new buffer from the current input file, perform end-of-line
3347 * translation, and update the crc and input file size.
3348 * IN assertion: size >= 2 (for end-of-line translation)
3350 int file_read(buf, size)
3356 Assert(insize == 0, "inbuf not empty");
3358 len = read(ifd, buf, size);
3359 if (len == (unsigned) (-1) || len == 0)
3362 crc = updcrc((uch *) buf, len);
3367 /* ===========================================================================
3368 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
3369 * (used for the compressed data only)
3376 write_buf(ofd, (char *) outbuf, outcnt);
3377 bytes_out += (ulg) outcnt;
projects / oweals / busybox.git / blob