source: MondoRescue/branches/stable/mindi-busybox/archival/gzip.c @ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 14 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 76.4 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Gzip implementation for busybox
4 *
5 * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly.
6 *
7 * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com>
8 *      "this is a stripped down version of gzip I put into busybox, it does
9 *      only standard in to standard out with -9 compression.  It also requires
10 *      the zcat module for some important functions."
11 *
12 * Adjusted further by Erik Andersen <andersen@codepoet.org> to support
13 * files as well as stdin/stdout, and to generally behave itself wrt
14 * command line handling.
15 *
16 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
17 */
18
19#define SMALL_MEM
20
21#include <stdlib.h>
22#include <stdio.h>
23#include <string.h>
24#include <unistd.h>
25#include <errno.h>
26#include <sys/types.h>
27#include <signal.h>
28#include <utime.h>
29#include <ctype.h>
30#include <sys/types.h>
31#include <unistd.h>
32#include <dirent.h>
33#include <fcntl.h>
34#include <time.h>
35#include "busybox.h"
36
37typedef unsigned char uch;
38typedef unsigned short ush;
39typedef unsigned long ulg;
40
41/* Return codes from gzip */
42#define OK      0
43#define ERROR   1
44#define WARNING 2
45
46/* Compression methods (see algorithm.doc) */
47/* Only STORED and DEFLATED are supported by this BusyBox module */
48#define STORED      0
49/* methods 4 to 7 reserved */
50#define DEFLATED    8
51
52/* To save memory for 16 bit systems, some arrays are overlaid between
53 * the various modules:
54 * deflate:  prev+head   window      d_buf  l_buf  outbuf
55 * unlzw:    tab_prefix  tab_suffix  stack  inbuf  outbuf
56 * For compression, input is done in window[]. For decompression, output
57 * is done in window except for unlzw.
58 */
59
60#ifndef INBUFSIZ
61#  ifdef SMALL_MEM
62#    define INBUFSIZ  0x2000    /* input buffer size */
63#  else
64#    define INBUFSIZ  0x8000    /* input buffer size */
65#  endif
66#endif
67#define INBUF_EXTRA  64 /* required by unlzw() */
68
69#ifndef OUTBUFSIZ
70#  ifdef SMALL_MEM
71#    define OUTBUFSIZ   8192    /* output buffer size */
72#  else
73#    define OUTBUFSIZ  16384    /* output buffer size */
74#  endif
75#endif
76#define OUTBUF_EXTRA 2048   /* required by unlzw() */
77
78#ifndef DIST_BUFSIZE
79#  ifdef SMALL_MEM
80#    define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
81#  else
82#    define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
83#  endif
84#endif
85
86#  define DECLARE(type, array, size)  static type * array
87#  define ALLOC(type, array, size) { \
88      array = (type*)xzalloc((size_t)(((size)+1L)/2) * 2*sizeof(type)); \
89   }
90#  define FREE(array) {free(array), array=NULL;}
91
92#define tab_suffix window
93#define tab_prefix prev /* hash link (see deflate.c) */
94#define head (prev+WSIZE)   /* hash head (see deflate.c) */
95
96static long bytes_in;   /* number of input bytes */
97
98#define isize bytes_in
99/* for compatibility with old zip sources (to be cleaned) */
100
101typedef int file_t;     /* Do not use stdio */
102
103#define NO_FILE  (-1)   /* in memory compression */
104
105
106#define PACK_MAGIC     "\037\036"   /* Magic header for packed files */
107#define GZIP_MAGIC     "\037\213"   /* Magic header for gzip files, 1F 8B */
108#define OLD_GZIP_MAGIC "\037\236"   /* Magic header for gzip 0.5 = freeze 1.x */
109#define LZH_MAGIC      "\037\240"   /* Magic header for SCO LZH Compress files */
110#define PKZIP_MAGIC    "\120\113\003\004"   /* Magic header for pkzip files */
111
112/* gzip flag byte */
113#define ASCII_FLAG   0x01   /* bit 0 set: file probably ascii text */
114#define CONTINUATION 0x02   /* bit 1 set: continuation of multi-part gzip file */
115#define EXTRA_FIELD  0x04   /* bit 2 set: extra field present */
116#define ORIG_NAME    0x08   /* bit 3 set: original file name present */
117#define COMMENT      0x10   /* bit 4 set: file comment present */
118#define RESERVED     0xC0   /* bit 6,7:   reserved */
119
120/* internal file attribute */
121#define UNKNOWN 0xffff
122#define BINARY  0
123#define ASCII   1
124
125#ifndef WSIZE
126#  define WSIZE 0x8000  /* window size--must be a power of two, and */
127#endif                          /*  at least 32K for zip's deflate method */
128
129#define MIN_MATCH  3
130#define MAX_MATCH  258
131/* The minimum and maximum match lengths */
132
133#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
134/* Minimum amount of lookahead, except at the end of the input file.
135 * See deflate.c for comments about the MIN_MATCH+1.
136 */
137
138#define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
139/* In order to simplify the code, particularly on 16 bit machines, match
140 * distances are limited to MAX_DIST instead of WSIZE.
141 */
142
143/* put_byte is used for the compressed output */
144#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
145   flush_outbuf();}
146
147
148/* Output a 32 bit value to the bit stream, lsb first */
149#if 0
150#define put_long(n) { \
151    put_short((n) & 0xffff); \
152    put_short(((ulg)(n)) >> 16); \
153}
154#endif
155
156#define seekable()    0 /* force sequential output */
157#define translate_eol 0 /* no option -a yet */
158
159/* Diagnostic functions */
160#ifdef DEBUG
161#  define Assert(cond,msg) {if(!(cond)) bb_error_msg(msg);}
162#  define Trace(x) fprintf x
163#  define Tracev(x) {if (verbose) fprintf x ;}
164#  define Tracevv(x) {if (verbose>1) fprintf x ;}
165#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
166#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
167#else
168#  define Assert(cond,msg)
169#  define Trace(x)
170#  define Tracev(x)
171#  define Tracevv(x)
172#  define Tracec(c,x)
173#  define Tracecv(c,x)
174#endif
175
176#define WARN(msg) {if (!quiet) fprintf msg ; \
177           if (exit_code == OK) exit_code = WARNING;}
178
179#ifndef MAX_PATH_LEN
180#  define MAX_PATH_LEN   1024   /* max pathname length */
181#endif
182
183
184    /* from zip.c: */
185static int zip(int in, int out);
186static int file_read(char *buf, unsigned size);
187
188        /* from deflate.c */
189static void lm_init(ush * flags);
190static ulg deflate(void);
191
192        /* from trees.c */
193static void ct_init(ush * attr, int *methodp);
194static int ct_tally(int dist, int lc);
195static ulg flush_block(char *buf, ulg stored_len, int eof);
196
197        /* from bits.c */
198static void bi_init(file_t zipfile);
199static void send_bits(int value, int length);
200static unsigned bi_reverse(unsigned value, int length);
201static void bi_windup(void);
202static void copy_block(char *buf, unsigned len, int header);
203static int (*read_buf) (char *buf, unsigned size);
204
205    /* from util.c: */
206static void flush_outbuf(void);
207
208/* lzw.h -- define the lzw functions.
209 * Copyright (C) 1992-1993 Jean-loup Gailly.
210 * This is free software; you can redistribute it and/or modify it under the
211 * terms of the GNU General Public License, see the file COPYING.
212 */
213
214#ifndef BITS
215#  define BITS 16
216#endif
217#define INIT_BITS 9     /* Initial number of bits per code */
218
219#define BIT_MASK    0x1f    /* Mask for 'number of compression bits' */
220/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
221 * It's a pity that old uncompress does not check bit 0x20. That makes
222 * extension of the format actually undesirable because old compress
223 * would just crash on the new format instead of giving a meaningful
224 * error message. It does check the number of bits, but it's more
225 * helpful to say "unsupported format, get a new version" than
226 * "can only handle 16 bits".
227 */
228
229/* tailor.h -- target dependent definitions
230 * Copyright (C) 1992-1993 Jean-loup Gailly.
231 * This is free software; you can redistribute it and/or modify it under the
232 * terms of the GNU General Public License, see the file COPYING.
233 */
234
235/* The target dependent definitions should be defined here only.
236 * The target dependent functions should be defined in tailor.c.
237 */
238
239
240    /* Common defaults */
241
242#ifndef OS_CODE
243#  define OS_CODE  0x03 /* assume Unix */
244#endif
245
246#ifndef PATH_SEP
247#  define PATH_SEP '/'
248#endif
249
250#ifndef OPTIONS_VAR
251#  define OPTIONS_VAR "GZIP"
252#endif
253
254#ifndef Z_SUFFIX
255#  define Z_SUFFIX ".gz"
256#endif
257
258#ifdef MAX_EXT_CHARS
259#  define MAX_SUFFIX  MAX_EXT_CHARS
260#else
261#  define MAX_SUFFIX  30
262#endif
263
264        /* global buffers */
265
266DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
267DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
268DECLARE(ush, d_buf, DIST_BUFSIZE);
269DECLARE(uch, window, 2L * WSIZE);
270DECLARE(ush, tab_prefix, 1L << BITS);
271
272static int foreground;  /* set if program run in foreground */
273static int method = DEFLATED;   /* compression method */
274static int exit_code = OK;  /* program exit code */
275static int part_nb;     /* number of parts in .gz file */
276static long time_stamp; /* original time stamp (modification time) */
277static long ifile_size; /* input file size, -1 for devices (debug only) */
278static char z_suffix[MAX_SUFFIX + 1];   /* default suffix (can be set with --suffix) */
279static int z_len;       /* strlen(z_suffix) */
280
281static int ifd;         /* input file descriptor */
282static int ofd;         /* output file descriptor */
283static unsigned insize; /* valid bytes in inbuf */
284static unsigned outcnt; /* bytes in output buffer */
285
286static uint32_t *crc_32_tab;
287
288/* Output a 16 bit value, lsb first */
289static void put_short(ush w)
290{
291    if (outcnt < OUTBUFSIZ - 2) {
292        outbuf[outcnt++] = (uch) ((w) & 0xff);
293        outbuf[outcnt++] = (uch) ((ush) (w) >> 8);
294    } else {
295        put_byte((uch) ((w) & 0xff));
296        put_byte((uch) ((ush) (w) >> 8));
297    }
298}
299
300/* ========================================================================
301 * Signal and error handler.
302 */
303static void abort_gzip(int ATTRIBUTE_UNUSED ignored)
304{
305    exit(ERROR);
306}
307
308/* ===========================================================================
309 * Clear input and output buffers
310 */
311static void clear_bufs(void)
312{
313    outcnt = 0;
314    insize = 0;
315    bytes_in = 0L;
316}
317
318/* ===========================================================================
319 * Does the same as write(), but also handles partial pipe writes and checks
320 * for error return.
321 */
322static void write_buf(int fd, void *buf, unsigned cnt)
323{
324    unsigned n;
325
326    while ((n = write(fd, buf, cnt)) != cnt) {
327        if (n == (unsigned) (-1)) bb_error_msg_and_die(bb_msg_write_error);
328        cnt -= n;
329        buf = (void *) ((char *) buf + n);
330    }
331}
332
333/* ===========================================================================
334 * Run a set of bytes through the crc shift register.  If s is a NULL
335 * pointer, then initialize the crc shift register contents instead.
336 * Return the current crc in either case.
337 */
338static uint32_t updcrc(uch * s, unsigned n)
339{
340    static uint32_t crc = ~0;   /* shift register contents */
341    uint32_t c;     /* temporary variable */
342
343    if (s == NULL) {
344        c = ~0;
345    } else {
346        c = crc;
347        if (n)
348            do {
349                c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8);
350            } while (--n);
351    }
352    crc = c;
353    return ~c;
354}
355
356/* bits.c -- output variable-length bit strings
357 * Copyright (C) 1992-1993 Jean-loup Gailly
358 * This is free software; you can redistribute it and/or modify it under the
359 * terms of the GNU General Public License, see the file COPYING.
360 */
361
362
363/*
364 *  PURPOSE
365 *
366 *      Output variable-length bit strings. Compression can be done
367 *      to a file or to memory. (The latter is not supported in this version.)
368 *
369 *  DISCUSSION
370 *
371 *      The PKZIP "deflate" file format interprets compressed file data
372 *      as a sequence of bits.  Multi-bit strings in the file may cross
373 *      byte boundaries without restriction.
374 *
375 *      The first bit of each byte is the low-order bit.
376 *
377 *      The routines in this file allow a variable-length bit value to
378 *      be output right-to-left (useful for literal values). For
379 *      left-to-right output (useful for code strings from the tree routines),
380 *      the bits must have been reversed first with bi_reverse().
381 *
382 *      For in-memory compression, the compressed bit stream goes directly
383 *      into the requested output buffer. The input data is read in blocks
384 *      by the mem_read() function. The buffer is limited to 64K on 16 bit
385 *      machines.
386 *
387 *  INTERFACE
388 *
389 *      void bi_init (FILE *zipfile)
390 *          Initialize the bit string routines.
391 *
392 *      void send_bits (int value, int length)
393 *          Write out a bit string, taking the source bits right to
394 *          left.
395 *
396 *      int bi_reverse (int value, int length)
397 *          Reverse the bits of a bit string, taking the source bits left to
398 *          right and emitting them right to left.
399 *
400 *      void bi_windup (void)
401 *          Write out any remaining bits in an incomplete byte.
402 *
403 *      void copy_block(char *buf, unsigned len, int header)
404 *          Copy a stored block to the zip file, storing first the length and
405 *          its one's complement if requested.
406 *
407 */
408
409/* ===========================================================================
410 * Local data used by the "bit string" routines.
411 */
412
413static file_t zfile;    /* output gzip file */
414
415static unsigned short bi_buf;
416
417/* Output buffer. bits are inserted starting at the bottom (least significant
418 * bits).
419 */
420
421#define Buf_size (8 * 2*sizeof(char))
422/* Number of bits used within bi_buf. (bi_buf might be implemented on
423 * more than 16 bits on some systems.)
424 */
425
426static int bi_valid;
427
428/* Current input function. Set to mem_read for in-memory compression */
429
430#ifdef DEBUG
431ulg bits_sent;          /* bit length of the compressed data */
432#endif
433
434/* ===========================================================================
435 * Initialize the bit string routines.
436 */
437static void bi_init(file_t zipfile)
438{
439    zfile = zipfile;
440    bi_buf = 0;
441    bi_valid = 0;
442#ifdef DEBUG
443    bits_sent = 0L;
444#endif
445
446    /* Set the defaults for file compression. They are set by memcompress
447     * for in-memory compression.
448     */
449    if (zfile != NO_FILE) {
450        read_buf = file_read;
451    }
452}
453
454/* ===========================================================================
455 * Send a value on a given number of bits.
456 * IN assertion: length <= 16 and value fits in length bits.
457 */
458static void send_bits(int value, int length)
459{
460#ifdef DEBUG
461    Tracev((stderr, " l %2d v %4x ", length, value));
462    Assert(length > 0 && length <= 15, "invalid length");
463    bits_sent += (ulg) length;
464#endif
465    /* If not enough room in bi_buf, use (valid) bits from bi_buf and
466     * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
467     * unused bits in value.
468     */
469    if (bi_valid > (int) Buf_size - length) {
470        bi_buf |= (value << bi_valid);
471        put_short(bi_buf);
472        bi_buf = (ush) value >> (Buf_size - bi_valid);
473        bi_valid += length - Buf_size;
474    } else {
475        bi_buf |= value << bi_valid;
476        bi_valid += length;
477    }
478}
479
480/* ===========================================================================
481 * Reverse the first len bits of a code, using straightforward code (a faster
482 * method would use a table)
483 * IN assertion: 1 <= len <= 15
484 */
485static unsigned bi_reverse(unsigned code, int len)
486{
487    register unsigned res = 0;
488
489    do {
490        res |= code & 1;
491        code >>= 1, res <<= 1;
492    } while (--len > 0);
493    return res >> 1;
494}
495
496/* ===========================================================================
497 * Write out any remaining bits in an incomplete byte.
498 */
499static void bi_windup(void)
500{
501    if (bi_valid > 8) {
502        put_short(bi_buf);
503    } else if (bi_valid > 0) {
504        put_byte(bi_buf);
505    }
506    bi_buf = 0;
507    bi_valid = 0;
508#ifdef DEBUG
509    bits_sent = (bits_sent + 7) & ~7;
510#endif
511}
512
513/* ===========================================================================
514 * Copy a stored block to the zip file, storing first the length and its
515 * one's complement if requested.
516 */
517static void copy_block(char *buf, unsigned len, int header)
518{
519    bi_windup();        /* align on byte boundary */
520
521    if (header) {
522        put_short((ush) len);
523        put_short((ush) ~ len);
524#ifdef DEBUG
525        bits_sent += 2 * 16;
526#endif
527    }
528#ifdef DEBUG
529    bits_sent += (ulg) len << 3;
530#endif
531    while (len--) {
532        put_byte(*buf++);
533    }
534}
535
536/* deflate.c -- compress data using the deflation algorithm
537 * Copyright (C) 1992-1993 Jean-loup Gailly
538 * This is free software; you can redistribute it and/or modify it under the
539 * terms of the GNU General Public License, see the file COPYING.
540 */
541
542/*
543 *  PURPOSE
544 *
545 *      Identify new text as repetitions of old text within a fixed-
546 *      length sliding window trailing behind the new text.
547 *
548 *  DISCUSSION
549 *
550 *      The "deflation" process depends on being able to identify portions
551 *      of the input text which are identical to earlier input (within a
552 *      sliding window trailing behind the input currently being processed).
553 *
554 *      The most straightforward technique turns out to be the fastest for
555 *      most input files: try all possible matches and select the longest.
556 *      The key feature of this algorithm is that insertions into the string
557 *      dictionary are very simple and thus fast, and deletions are avoided
558 *      completely. Insertions are performed at each input character, whereas
559 *      string matches are performed only when the previous match ends. So it
560 *      is preferable to spend more time in matches to allow very fast string
561 *      insertions and avoid deletions. The matching algorithm for small
562 *      strings is inspired from that of Rabin & Karp. A brute force approach
563 *      is used to find longer strings when a small match has been found.
564 *      A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
565 *      (by Leonid Broukhis).
566 *         A previous version of this file used a more sophisticated algorithm
567 *      (by Fiala and Greene) which is guaranteed to run in linear amortized
568 *      time, but has a larger average cost, uses more memory and is patented.
569 *      However the F&G algorithm may be faster for some highly redundant
570 *      files if the parameter max_chain_length (described below) is too large.
571 *
572 *  ACKNOWLEDGMENTS
573 *
574 *      The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
575 *      I found it in 'freeze' written by Leonid Broukhis.
576 *      Thanks to many info-zippers for bug reports and testing.
577 *
578 *  REFERENCES
579 *
580 *      APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
581 *
582 *      A description of the Rabin and Karp algorithm is given in the book
583 *         "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
584 *
585 *      Fiala,E.R., and Greene,D.H.
586 *         Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
587 *
588 *  INTERFACE
589 *
590 *      void lm_init (int pack_level, ush *flags)
591 *          Initialize the "longest match" routines for a new file
592 *
593 *      ulg deflate (void)
594 *          Processes a new input file and return its compressed length. Sets
595 *          the compressed length, crc, deflate flags and internal file
596 *          attributes.
597 */
598
599
600/* ===========================================================================
601 * Configuration parameters
602 */
603
604/* Compile with MEDIUM_MEM to reduce the memory requirements or
605 * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the
606 * entire input file can be held in memory (not possible on 16 bit systems).
607 * Warning: defining these symbols affects HASH_BITS (see below) and thus
608 * affects the compression ratio. The compressed output
609 * is still correct, and might even be smaller in some cases.
610 */
611
612#ifdef SMALL_MEM
613#   define HASH_BITS  13    /* Number of bits used to hash strings */
614#endif
615#ifdef MEDIUM_MEM
616#   define HASH_BITS  14
617#endif
618#ifndef HASH_BITS
619#   define HASH_BITS  15
620   /* For portability to 16 bit machines, do not use values above 15. */
621#endif
622
623/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and
624 * window with tab_suffix. Check that we can do this:
625 */
626#if (WSIZE<<1) > (1<<BITS)
627#  error cannot overlay window with tab_suffix and prev with tab_prefix0
628#endif
629#if HASH_BITS > BITS-1
630#  error cannot overlay head with tab_prefix1
631#endif
632#define HASH_SIZE (unsigned)(1<<HASH_BITS)
633#define HASH_MASK (HASH_SIZE-1)
634#define WMASK     (WSIZE-1)
635/* HASH_SIZE and WSIZE must be powers of two */
636#define NIL 0
637/* Tail of hash chains */
638#define FAST 4
639#define SLOW 2
640/* speed options for the general purpose bit flag */
641#ifndef TOO_FAR
642#  define TOO_FAR 4096
643#endif
644/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
645/* ===========================================================================
646 * Local data used by the "longest match" routines.
647 */
648typedef ush Pos;
649typedef unsigned IPos;
650
651/* A Pos is an index in the character window. We use short instead of int to
652 * save space in the various tables. IPos is used only for parameter passing.
653 */
654
655/* DECLARE(uch, window, 2L*WSIZE); */
656/* Sliding window. Input bytes are read into the second half of the window,
657 * and move to the first half later to keep a dictionary of at least WSIZE
658 * bytes. With this organization, matches are limited to a distance of
659 * WSIZE-MAX_MATCH bytes, but this ensures that IO is always
660 * performed with a length multiple of the block size. Also, it limits
661 * the window size to 64K, which is quite useful on MSDOS.
662 * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would
663 * be less efficient).
664 */
665
666/* DECLARE(Pos, prev, WSIZE); */
667/* Link to older string with same hash index. To limit the size of this
668 * array to 64K, this link is maintained only for the last 32K strings.
669 * An index in this array is thus a window index modulo 32K.
670 */
671
672/* DECLARE(Pos, head, 1<<HASH_BITS); */
673/* Heads of the hash chains or NIL. */
674
675static const ulg window_size = (ulg) 2 * WSIZE;
676
677/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
678 * input file length plus MIN_LOOKAHEAD.
679 */
680
681static long block_start;
682
683/* window position at the beginning of the current output block. Gets
684 * negative when the window is moved backwards.
685 */
686
687static unsigned ins_h;  /* hash index of string to be inserted */
688
689#define H_SHIFT  ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH)
690/* Number of bits by which ins_h and del_h must be shifted at each
691 * input step. It must be such that after MIN_MATCH steps, the oldest
692 * byte no longer takes part in the hash key, that is:
693 *   H_SHIFT * MIN_MATCH >= HASH_BITS
694 */
695
696static unsigned int prev_length;
697
698/* Length of the best match at previous step. Matches not greater than this
699 * are discarded. This is used in the lazy match evaluation.
700 */
701
702static unsigned strstart;   /* start of string to insert */
703static unsigned match_start;    /* start of matching string */
704static int eofile;      /* flag set at end of input file */
705static unsigned lookahead;  /* number of valid bytes ahead in window */
706
707enum {
708    max_chain_length = 4096,
709
710/* To speed up deflation, hash chains are never searched beyond this length.
711 * A higher limit improves compression ratio but degrades the speed.
712 */
713
714    max_lazy_match = 258,
715
716/* Attempt to find a better match only when the current match is strictly
717 * smaller than this value. This mechanism is used only for compression
718 * levels >= 4.
719 */
720    max_insert_length = max_lazy_match,
721/* Insert new strings in the hash table only if the match length
722 * is not greater than this length. This saves time but degrades compression.
723 * max_insert_length is used only for compression levels <= 3.
724 */
725
726    good_match = 32,
727
728/* Use a faster search when the previous match is longer than this */
729
730
731/* Values for max_lazy_match, good_match and max_chain_length, depending on
732 * the desired pack level (0..9). The values given below have been tuned to
733 * exclude worst case performance for pathological files. Better values may be
734 * found for specific files.
735 */
736
737    nice_match = 258    /* Stop searching when current match exceeds this */
738
739/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
740 * For deflate_fast() (levels <= 3) good is ignored and lazy has a different
741 * meaning.
742 */
743};
744
745#define EQUAL 0
746/* result of memcmp for equal strings */
747
748/* ===========================================================================
749 *  Prototypes for local functions.
750 */
751static void fill_window(void);
752
753static int longest_match(IPos cur_match);
754
755#ifdef DEBUG
756static void check_match(IPos start, IPos match, int length);
757#endif
758
759/* ===========================================================================
760 * Update a hash value with the given input byte
761 * IN  assertion: all calls to to UPDATE_HASH are made with consecutive
762 *    input characters, so that a running hash key can be computed from the
763 *    previous key instead of complete recalculation each time.
764 */
765#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
766
767/* ===========================================================================
768 * Insert string s in the dictionary and set match_head to the previous head
769 * of the hash chain (the most recent string with same hash key). Return
770 * the previous length of the hash chain.
771 * IN  assertion: all calls to to INSERT_STRING are made with consecutive
772 *    input characters and the first MIN_MATCH bytes of s are valid
773 *    (except for the last MIN_MATCH-1 bytes of the input file).
774 */
775#define INSERT_STRING(s, match_head) \
776   (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
777    prev[(s) & WMASK] = match_head = head[ins_h], \
778    head[ins_h] = (s))
779
780/* ===========================================================================
781 * Initialize the "longest match" routines for a new file
782 */
783static void lm_init(ush * flags)
784{
785    register unsigned j;
786
787    /* Initialize the hash table. */
788    memset(head, 0, HASH_SIZE * sizeof(*head));
789    /* prev will be initialized on the fly */
790
791    *flags |= SLOW;
792    /* ??? reduce max_chain_length for binary files */
793
794    strstart = 0;
795    block_start = 0L;
796
797    lookahead = read_buf((char *) window,
798                         sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
799
800    if (lookahead == 0 || lookahead == (unsigned) EOF) {
801        eofile = 1, lookahead = 0;
802        return;
803    }
804    eofile = 0;
805    /* Make sure that we always have enough lookahead. This is important
806     * if input comes from a device such as a tty.
807     */
808    while (lookahead < MIN_LOOKAHEAD && !eofile)
809        fill_window();
810
811    ins_h = 0;
812    for (j = 0; j < MIN_MATCH - 1; j++)
813        UPDATE_HASH(ins_h, window[j]);
814    /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
815     * not important since only literal bytes will be emitted.
816     */
817}
818
819/* ===========================================================================
820 * Set match_start to the longest match starting at the given string and
821 * return its length. Matches shorter or equal to prev_length are discarded,
822 * in which case the result is equal to prev_length and match_start is
823 * garbage.
824 * IN assertions: cur_match is the head of the hash chain for the current
825 *   string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
826 */
827
828/* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or
829 * match.s. The code is functionally equivalent, so you can use the C version
830 * if desired.
831 */
832static int longest_match(IPos cur_match)
833{
834    unsigned chain_length = max_chain_length;   /* max hash chain length */
835    register uch *scan = window + strstart; /* current string */
836    register uch *match;    /* matched string */
837    register int len;   /* length of current match */
838    int best_len = prev_length; /* best match length so far */
839    IPos limit =
840        strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL;
841    /* Stop when cur_match becomes <= limit. To simplify the code,
842     * we prevent matches with the string of window index 0.
843     */
844
845/* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
846 * It is easy to get rid of this optimization if necessary.
847 */
848#if HASH_BITS < 8 || MAX_MATCH != 258
849#  error Code too clever
850#endif
851    register uch *strend = window + strstart + MAX_MATCH;
852    register uch scan_end1 = scan[best_len - 1];
853    register uch scan_end = scan[best_len];
854
855    /* Do not waste too much time if we already have a good match: */
856    if (prev_length >= good_match) {
857        chain_length >>= 2;
858    }
859    Assert(strstart <= window_size - MIN_LOOKAHEAD, "insufficient lookahead");
860
861    do {
862        Assert(cur_match < strstart, "no future");
863        match = window + cur_match;
864
865        /* Skip to next match if the match length cannot increase
866         * or if the match length is less than 2:
867         */
868        if (match[best_len] != scan_end ||
869            match[best_len - 1] != scan_end1 ||
870            *match != *scan || *++match != scan[1])
871            continue;
872
873        /* The check at best_len-1 can be removed because it will be made
874         * again later. (This heuristic is not always a win.)
875         * It is not necessary to compare scan[2] and match[2] since they
876         * are always equal when the other bytes match, given that
877         * the hash keys are equal and that HASH_BITS >= 8.
878         */
879        scan += 2, match++;
880
881        /* We check for insufficient lookahead only every 8th comparison;
882         * the 256th check will be made at strstart+258.
883         */
884        do {
885        } while (*++scan == *++match && *++scan == *++match &&
886                 *++scan == *++match && *++scan == *++match &&
887                 *++scan == *++match && *++scan == *++match &&
888                 *++scan == *++match && *++scan == *++match && scan < strend);
889
890        len = MAX_MATCH - (int) (strend - scan);
891        scan = strend - MAX_MATCH;
892
893        if (len > best_len) {
894            match_start = cur_match;
895            best_len = len;
896            if (len >= nice_match)
897                break;
898            scan_end1 = scan[best_len - 1];
899            scan_end = scan[best_len];
900        }
901    } while ((cur_match = prev[cur_match & WMASK]) > limit
902             && --chain_length != 0);
903
904    return best_len;
905}
906
907#ifdef DEBUG
908/* ===========================================================================
909 * Check that the match at match_start is indeed a match.
910 */
911static void check_match(IPos start, IPos match, int length)
912{
913    /* check that the match is indeed a match */
914    if (memcmp((char *) window + match,
915               (char *) window + start, length) != EQUAL) {
916        bb_error_msg(" start %d, match %d, length %d", start, match, length);
917        bb_error_msg("invalid match");
918    }
919    if (verbose > 1) {
920        bb_error_msg("\\[%d,%d]", start - match, length);
921        do {
922            putc(window[start++], stderr);
923        } while (--length != 0);
924    }
925}
926#else
927#  define check_match(start, match, length)
928#endif
929
930/* ===========================================================================
931 * Fill the window when the lookahead becomes insufficient.
932 * Updates strstart and lookahead, and sets eofile if end of input file.
933 * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
934 * OUT assertions: at least one byte has been read, or eofile is set;
935 *    file reads are performed for at least two bytes (required for the
936 *    translate_eol option).
937 */
938static void fill_window(void)
939{
940    register unsigned n, m;
941    unsigned more =
942        (unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
943    /* Amount of free space at the end of the window. */
944
945    /* If the window is almost full and there is insufficient lookahead,
946     * move the upper half to the lower one to make room in the upper half.
947     */
948    if (more == (unsigned) EOF) {
949        /* Very unlikely, but possible on 16 bit machine if strstart == 0
950         * and lookahead == 1 (input done one byte at time)
951         */
952        more--;
953    } else if (strstart >= WSIZE + MAX_DIST) {
954        /* By the IN assertion, the window is not empty so we can't confuse
955         * more == 0 with more == 64K on a 16 bit machine.
956         */
957        Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM");
958
959        memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE);
960        match_start -= WSIZE;
961        strstart -= WSIZE;  /* we now have strstart >= MAX_DIST: */
962
963        block_start -= (long) WSIZE;
964
965        for (n = 0; n < HASH_SIZE; n++) {
966            m = head[n];
967            head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
968        }
969        for (n = 0; n < WSIZE; n++) {
970            m = prev[n];
971            prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
972            /* If n is not on any hash chain, prev[n] is garbage but
973             * its value will never be used.
974             */
975        }
976        more += WSIZE;
977    }
978    /* At this point, more >= 2 */
979    if (!eofile) {
980        n = read_buf((char *) window + strstart + lookahead, more);
981        if (n == 0 || n == (unsigned) EOF) {
982            eofile = 1;
983        } else {
984            lookahead += n;
985        }
986    }
987}
988
989/* ===========================================================================
990 * Flush the current block, with given end-of-file flag.
991 * IN assertion: strstart is set to the end of the current match.
992 */
993#define FLUSH_BLOCK(eof) \
994   flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
995        (char*)NULL, (long)strstart - block_start, (eof))
996
997/* ===========================================================================
998 * Same as above, but achieves better compression. We use a lazy
999 * evaluation for matches: a match is finally adopted only if there is
1000 * no better match at the next window position.
1001 */
1002static ulg deflate(void)
1003{
1004    IPos hash_head;     /* head of hash chain */
1005    IPos prev_match;    /* previous match */
1006    int flush;          /* set if current block must be flushed */
1007    int match_available = 0;    /* set if previous match exists */
1008    register unsigned match_length = MIN_MATCH - 1; /* length of best match */
1009
1010    /* Process the input block. */
1011    while (lookahead != 0) {
1012        /* Insert the string window[strstart .. strstart+2] in the
1013         * dictionary, and set hash_head to the head of the hash chain:
1014         */
1015        INSERT_STRING(strstart, hash_head);
1016
1017        /* Find the longest match, discarding those <= prev_length.
1018         */
1019        prev_length = match_length, prev_match = match_start;
1020        match_length = MIN_MATCH - 1;
1021
1022        if (hash_head != NIL && prev_length < max_lazy_match &&
1023            strstart - hash_head <= MAX_DIST) {
1024            /* To simplify the code, we prevent matches with the string
1025             * of window index 0 (in particular we have to avoid a match
1026             * of the string with itself at the start of the input file).
1027             */
1028            match_length = longest_match(hash_head);
1029            /* longest_match() sets match_start */
1030            if (match_length > lookahead)
1031                match_length = lookahead;
1032
1033            /* Ignore a length 3 match if it is too distant: */
1034            if (match_length == MIN_MATCH && strstart - match_start > TOO_FAR) {
1035                /* If prev_match is also MIN_MATCH, match_start is garbage
1036                 * but we will ignore the current match anyway.
1037                 */
1038                match_length--;
1039            }
1040        }
1041        /* If there was a match at the previous step and the current
1042         * match is not better, output the previous match:
1043         */
1044        if (prev_length >= MIN_MATCH && match_length <= prev_length) {
1045
1046            check_match(strstart - 1, prev_match, prev_length);
1047
1048            flush =
1049                ct_tally(strstart - 1 - prev_match, prev_length - MIN_MATCH);
1050
1051            /* Insert in hash table all strings up to the end of the match.
1052             * strstart-1 and strstart are already inserted.
1053             */
1054            lookahead -= prev_length - 1;
1055            prev_length -= 2;
1056            do {
1057                strstart++;
1058                INSERT_STRING(strstart, hash_head);
1059                /* strstart never exceeds WSIZE-MAX_MATCH, so there are
1060                 * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
1061                 * these bytes are garbage, but it does not matter since the
1062                 * next lookahead bytes will always be emitted as literals.
1063                 */
1064            } while (--prev_length != 0);
1065            match_available = 0;
1066            match_length = MIN_MATCH - 1;
1067            strstart++;
1068            if (flush)
1069                FLUSH_BLOCK(0), block_start = strstart;
1070
1071        } else if (match_available) {
1072            /* If there was no match at the previous position, output a
1073             * single literal. If there was a match but the current match
1074             * is longer, truncate the previous match to a single literal.
1075             */
1076            Tracevv((stderr, "%c", window[strstart - 1]));
1077            if (ct_tally(0, window[strstart - 1])) {
1078                FLUSH_BLOCK(0), block_start = strstart;
1079            }
1080            strstart++;
1081            lookahead--;
1082        } else {
1083            /* There is no previous match to compare with, wait for
1084             * the next step to decide.
1085             */
1086            match_available = 1;
1087            strstart++;
1088            lookahead--;
1089        }
1090        Assert(strstart <= isize && lookahead <= isize, "a bit too far");
1091
1092        /* Make sure that we always have enough lookahead, except
1093         * at the end of the input file. We need MAX_MATCH bytes
1094         * for the next match, plus MIN_MATCH bytes to insert the
1095         * string following the next match.
1096         */
1097        while (lookahead < MIN_LOOKAHEAD && !eofile)
1098            fill_window();
1099    }
1100    if (match_available)
1101        ct_tally(0, window[strstart - 1]);
1102
1103    return FLUSH_BLOCK(1);  /* eof */
1104}
1105
1106/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
1107 * Copyright (C) 1992-1993 Jean-loup Gailly
1108 * The unzip code was written and put in the public domain by Mark Adler.
1109 * Portions of the lzw code are derived from the public domain 'compress'
1110 * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
1111 * Ken Turkowski, Dave Mack and Peter Jannesen.
1112 *
1113 * See the license_msg below and the file COPYING for the software license.
1114 * See the file algorithm.doc for the compression algorithms and file formats.
1115 */
1116
1117/* Compress files with zip algorithm and 'compress' interface.
1118 * See usage() and help() functions below for all options.
1119 * Outputs:
1120 *        file.gz:   compressed file with same mode, owner, and utimes
1121 *     or stdout with -c option or if stdin used as input.
1122 * If the output file name had to be truncated, the original name is kept
1123 * in the compressed file.
1124 */
1125
1126        /* configuration */
1127
1128typedef struct dirent dir_type;
1129
1130/* ======================================================================== */
1131int gzip_main(int argc, char **argv)
1132{
1133    int result;
1134    int inFileNum;
1135    int outFileNum;
1136    struct stat statBuf;
1137    char *delFileName;
1138    int tostdout = 0;
1139    int force = 0;
1140    int opt;
1141
1142    while ((opt = getopt(argc, argv, "cf123456789dq")) != -1) {
1143        switch (opt) {
1144        case 'c':
1145            tostdout = 1;
1146            break;
1147        case 'f':
1148            force = 1;
1149            break;
1150            /* Ignore 1-9 (compression level) options */
1151        case '1':
1152        case '2':
1153        case '3':
1154        case '4':
1155        case '5':
1156        case '6':
1157        case '7':
1158        case '8':
1159        case '9':
1160            break;
1161        case 'q':
1162            break;
1163#ifdef CONFIG_GUNZIP
1164        case 'd':
1165            optind = 1;
1166            return gunzip_main(argc, argv);
1167#endif
1168        default:
1169            bb_show_usage();
1170        }
1171    }
1172
1173    foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
1174    if (foreground) {
1175        (void) signal(SIGINT, abort_gzip);
1176    }
1177#ifdef SIGTERM
1178    if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
1179        (void) signal(SIGTERM, abort_gzip);
1180    }
1181#endif
1182#ifdef SIGHUP
1183    if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
1184        (void) signal(SIGHUP, abort_gzip);
1185    }
1186#endif
1187
1188    strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
1189    z_len = strlen(z_suffix);
1190
1191    /* Allocate all global buffers (for DYN_ALLOC option) */
1192    ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA);
1193    ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA);
1194    ALLOC(ush, d_buf, DIST_BUFSIZE);
1195    ALLOC(uch, window, 2L * WSIZE);
1196    ALLOC(ush, tab_prefix, 1L << BITS);
1197
1198    /* Initialise the CRC32 table */
1199    crc_32_tab = bb_crc32_filltable(0);
1200   
1201    clear_bufs();
1202    part_nb = 0;
1203
1204    if (optind == argc) {
1205        time_stamp = 0;
1206        ifile_size = -1L;
1207        zip(STDIN_FILENO, STDOUT_FILENO);
1208    } else {
1209        int i;
1210
1211        for (i = optind; i < argc; i++) {
1212            char *path = NULL;
1213
1214            clear_bufs();
1215            if (strcmp(argv[i], "-") == 0) {
1216                time_stamp = 0;
1217                ifile_size = -1L;
1218                inFileNum = STDIN_FILENO;
1219                outFileNum = STDOUT_FILENO;
1220            } else {
1221                inFileNum = bb_xopen3(argv[i], O_RDONLY, 0);
1222                if (fstat(inFileNum, &statBuf) < 0)
1223                    bb_perror_msg_and_die("%s", argv[i]);
1224                time_stamp = statBuf.st_ctime;
1225                ifile_size = statBuf.st_size;
1226
1227                if (!tostdout) {
1228                    path = xmalloc(strlen(argv[i]) + 4);
1229                    strcpy(path, argv[i]);
1230                    strcat(path, ".gz");
1231
1232                    /* Open output file */
1233#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) && defined O_NOFOLLOW
1234                    outFileNum =
1235                        open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
1236#else
1237                    outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL);
1238#endif
1239                    if (outFileNum < 0) {
1240                        bb_perror_msg("%s", path);
1241                        free(path);
1242                        continue;
1243                    }
1244
1245                    /* Set permissions on the file */
1246                    fchmod(outFileNum, statBuf.st_mode);
1247                } else
1248                    outFileNum = STDOUT_FILENO;
1249            }
1250
1251            if (path == NULL && isatty(outFileNum) && force == 0) {
1252                bb_error_msg
1253                    ("compressed data not written to a terminal. Use -f to force compression.");
1254                free(path);
1255                continue;
1256            }
1257
1258            result = zip(inFileNum, outFileNum);
1259
1260            if (path != NULL) {
1261                close(inFileNum);
1262                close(outFileNum);
1263
1264                /* Delete the original file */
1265                if (result == OK)
1266                    delFileName = argv[i];
1267                else
1268                    delFileName = path;
1269
1270                if (unlink(delFileName) < 0)
1271                    bb_perror_msg("%s", delFileName);
1272            }
1273
1274            free(path);
1275        }
1276    }
1277
1278    return (exit_code);
1279}
1280
1281/* trees.c -- output deflated data using Huffman coding
1282 * Copyright (C) 1992-1993 Jean-loup Gailly
1283 * This is free software; you can redistribute it and/or modify it under the
1284 * terms of the GNU General Public License, see the file COPYING.
1285 */
1286
1287/*
1288 *  PURPOSE
1289 *
1290 *      Encode various sets of source values using variable-length
1291 *      binary code trees.
1292 *
1293 *  DISCUSSION
1294 *
1295 *      The PKZIP "deflation" process uses several Huffman trees. The more
1296 *      common source values are represented by shorter bit sequences.
1297 *
1298 *      Each code tree is stored in the ZIP file in a compressed form
1299 *      which is itself a Huffman encoding of the lengths of
1300 *      all the code strings (in ascending order by source values).
1301 *      The actual code strings are reconstructed from the lengths in
1302 *      the UNZIP process, as described in the "application note"
1303 *      (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
1304 *
1305 *  REFERENCES
1306 *
1307 *      Lynch, Thomas J.
1308 *          Data Compression:  Techniques and Applications, pp. 53-55.
1309 *          Lifetime Learning Publications, 1985.  ISBN 0-534-03418-7.
1310 *
1311 *      Storer, James A.
1312 *          Data Compression:  Methods and Theory, pp. 49-50.
1313 *          Computer Science Press, 1988.  ISBN 0-7167-8156-5.
1314 *
1315 *      Sedgewick, R.
1316 *          Algorithms, p290.
1317 *          Addison-Wesley, 1983. ISBN 0-201-06672-6.
1318 *
1319 *  INTERFACE
1320 *
1321 *      void ct_init (ush *attr, int *methodp)
1322 *          Allocate the match buffer, initialize the various tables and save
1323 *          the location of the internal file attribute (ascii/binary) and
1324 *          method (DEFLATE/STORE)
1325 *
1326 *      void ct_tally (int dist, int lc);
1327 *          Save the match info and tally the frequency counts.
1328 *
1329 *      long flush_block (char *buf, ulg stored_len, int eof)
1330 *          Determine the best encoding for the current block: dynamic trees,
1331 *          static trees or store, and output the encoded block to the zip
1332 *          file. Returns the total compressed length for the file so far.
1333 *
1334 */
1335
1336/* ===========================================================================
1337 * Constants
1338 */
1339
1340#define MAX_BITS 15
1341/* All codes must not exceed MAX_BITS bits */
1342
1343#define MAX_BL_BITS 7
1344/* Bit length codes must not exceed MAX_BL_BITS bits */
1345
1346#define LENGTH_CODES 29
1347/* number of length codes, not counting the special END_BLOCK code */
1348
1349#define LITERALS  256
1350/* number of literal bytes 0..255 */
1351
1352#define END_BLOCK 256
1353/* end of block literal code */
1354
1355#define L_CODES (LITERALS+1+LENGTH_CODES)
1356/* number of Literal or Length codes, including the END_BLOCK code */
1357
1358#define D_CODES   30
1359/* number of distance codes */
1360
1361#define BL_CODES  19
1362/* number of codes used to transfer the bit lengths */
1363
1364typedef uch extra_bits_t;
1365
1366/* extra bits for each length code */
1367static const extra_bits_t extra_lbits[LENGTH_CODES]
1368    = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
1369    4, 4, 5, 5, 5, 5, 0
1370};
1371
1372/* extra bits for each distance code */
1373static const extra_bits_t extra_dbits[D_CODES]
1374    = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
1375    10, 10, 11, 11, 12, 12, 13, 13
1376};
1377
1378/* extra bits for each bit length code */
1379static const extra_bits_t extra_blbits[BL_CODES]
1380= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
1381
1382#define STORED_BLOCK 0
1383#define STATIC_TREES 1
1384#define DYN_TREES    2
1385/* The three kinds of block type */
1386
1387#ifndef LIT_BUFSIZE
1388#  ifdef SMALL_MEM
1389#    define LIT_BUFSIZE  0x2000
1390#  else
1391#  ifdef MEDIUM_MEM
1392#    define LIT_BUFSIZE  0x4000
1393#  else
1394#    define LIT_BUFSIZE  0x8000
1395#  endif
1396#  endif
1397#endif
1398#ifndef DIST_BUFSIZE
1399#  define DIST_BUFSIZE  LIT_BUFSIZE
1400#endif
1401/* Sizes of match buffers for literals/lengths and distances.  There are
1402 * 4 reasons for limiting LIT_BUFSIZE to 64K:
1403 *   - frequencies can be kept in 16 bit counters
1404 *   - if compression is not successful for the first block, all input data is
1405 *     still in the window so we can still emit a stored block even when input
1406 *     comes from standard input.  (This can also be done for all blocks if
1407 *     LIT_BUFSIZE is not greater than 32K.)
1408 *   - if compression is not successful for a file smaller than 64K, we can
1409 *     even emit a stored file instead of a stored block (saving 5 bytes).
1410 *   - creating new Huffman trees less frequently may not provide fast
1411 *     adaptation to changes in the input data statistics. (Take for
1412 *     example a binary file with poorly compressible code followed by
1413 *     a highly compressible string table.) Smaller buffer sizes give
1414 *     fast adaptation but have of course the overhead of transmitting trees
1415 *     more frequently.
1416 *   - I can't count above 4
1417 * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
1418 * memory at the expense of compression). Some optimizations would be possible
1419 * if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
1420 */
1421#if LIT_BUFSIZE > INBUFSIZ
1422#error cannot overlay l_buf and inbuf
1423#endif
1424#define REP_3_6      16
1425/* repeat previous bit length 3-6 times (2 bits of repeat count) */
1426#define REPZ_3_10    17
1427/* repeat a zero length 3-10 times  (3 bits of repeat count) */
1428#define REPZ_11_138  18
1429/* repeat a zero length 11-138 times  (7 bits of repeat count) */
1430
1431/* ===========================================================================
1432 * Local data
1433 */
1434
1435/* Data structure describing a single value and its code string. */
1436typedef struct ct_data {
1437    union {
1438        ush freq;       /* frequency count */
1439        ush code;       /* bit string */
1440    } fc;
1441    union {
1442        ush dad;        /* father node in Huffman tree */
1443        ush len;        /* length of bit string */
1444    } dl;
1445} ct_data;
1446
1447#define Freq fc.freq
1448#define Code fc.code
1449#define Dad  dl.dad
1450#define Len  dl.len
1451
1452#define HEAP_SIZE (2*L_CODES+1)
1453/* maximum heap size */
1454
1455static ct_data dyn_ltree[HEAP_SIZE];    /* literal and length tree */
1456static ct_data dyn_dtree[2 * D_CODES + 1];  /* distance tree */
1457
1458static ct_data static_ltree[L_CODES + 2];
1459
1460/* The static literal tree. Since the bit lengths are imposed, there is no
1461 * need for the L_CODES extra codes used during heap construction. However
1462 * The codes 286 and 287 are needed to build a canonical tree (see ct_init
1463 * below).
1464 */
1465
1466static ct_data static_dtree[D_CODES];
1467
1468/* The static distance tree. (Actually a trivial tree since all codes use
1469 * 5 bits.)
1470 */
1471
1472static ct_data bl_tree[2 * BL_CODES + 1];
1473
1474/* Huffman tree for the bit lengths */
1475
1476typedef struct tree_desc {
1477    ct_data *dyn_tree;  /* the dynamic tree */
1478    ct_data *static_tree;   /* corresponding static tree or NULL */
1479    const extra_bits_t *extra_bits; /* extra bits for each code or NULL */
1480    int extra_base;     /* base index for extra_bits */
1481    int elems;          /* max number of elements in the tree */
1482    int max_length;     /* max bit length for the codes */
1483    int max_code;       /* largest code with non zero frequency */
1484} tree_desc;
1485
1486static tree_desc l_desc =
1487    { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES,
1488    MAX_BITS, 0
1489};
1490
1491static tree_desc d_desc =
1492    { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 };
1493
1494static tree_desc bl_desc =
1495    { bl_tree, (ct_data *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS,
1496    0
1497};
1498
1499
1500static ush bl_count[MAX_BITS + 1];
1501
1502/* number of codes at each bit length for an optimal tree */
1503
1504static const uch bl_order[BL_CODES]
1505= { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
1506
1507/* The lengths of the bit length codes are sent in order of decreasing
1508 * probability, to avoid transmitting the lengths for unused bit length codes.
1509 */
1510
1511static int heap[2 * L_CODES + 1];   /* heap used to build the Huffman trees */
1512static int heap_len;    /* number of elements in the heap */
1513static int heap_max;    /* element of largest frequency */
1514
1515/* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used.
1516 * The same heap array is used to build all trees.
1517 */
1518
1519static uch depth[2 * L_CODES + 1];
1520
1521/* Depth of each subtree used as tie breaker for trees of equal frequency */
1522
1523static uch length_code[MAX_MATCH - MIN_MATCH + 1];
1524
1525/* length code for each normalized match length (0 == MIN_MATCH) */
1526
1527static uch dist_code[512];
1528
1529/* distance codes. The first 256 values correspond to the distances
1530 * 3 .. 258, the last 256 values correspond to the top 8 bits of
1531 * the 15 bit distances.
1532 */
1533
1534static int base_length[LENGTH_CODES];
1535
1536/* First normalized length for each code (0 = MIN_MATCH) */
1537
1538static int base_dist[D_CODES];
1539
1540/* First normalized distance for each code (0 = distance of 1) */
1541
1542#define l_buf inbuf
1543/* DECLARE(uch, l_buf, LIT_BUFSIZE);  buffer for literals or lengths */
1544
1545/* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */
1546
1547static uch flag_buf[(LIT_BUFSIZE / 8)];
1548
1549/* flag_buf is a bit array distinguishing literals from lengths in
1550 * l_buf, thus indicating the presence or absence of a distance.
1551 */
1552
1553static unsigned last_lit;   /* running index in l_buf */
1554static unsigned last_dist;  /* running index in d_buf */
1555static unsigned last_flags; /* running index in flag_buf */
1556static uch flags;       /* current flags not yet saved in flag_buf */
1557static uch flag_bit;    /* current bit used in flags */
1558
1559/* bits are filled in flags starting at bit 0 (least significant).
1560 * Note: these flags are overkill in the current code since we don't
1561 * take advantage of DIST_BUFSIZE == LIT_BUFSIZE.
1562 */
1563
1564static ulg opt_len;     /* bit length of current block with optimal trees */
1565static ulg static_len;  /* bit length of current block with static trees */
1566
1567static ulg compressed_len;  /* total bit length of compressed file */
1568
1569
1570static ush *file_type;  /* pointer to UNKNOWN, BINARY or ASCII */
1571static int *file_method;    /* pointer to DEFLATE or STORE */
1572
1573/* ===========================================================================
1574 * Local (static) routines in this file.
1575 */
1576
1577static void init_block(void);
1578static void pqdownheap(ct_data * tree, int k);
1579static void gen_bitlen(tree_desc * desc);
1580static void gen_codes(ct_data * tree, int max_code);
1581static void build_tree(tree_desc * desc);
1582static void scan_tree(ct_data * tree, int max_code);
1583static void send_tree(ct_data * tree, int max_code);
1584static int build_bl_tree(void);
1585static void send_all_trees(int lcodes, int dcodes, int blcodes);
1586static void compress_block(ct_data * ltree, ct_data * dtree);
1587static void set_file_type(void);
1588
1589
1590#ifndef DEBUG
1591#  define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
1592   /* Send a code of the given tree. c and tree must not have side effects */
1593
1594#else                           /* DEBUG */
1595#  define send_code(c, tree) \
1596     { if (verbose>1) bb_error_msg("\ncd %3d ",(c)); \
1597       send_bits(tree[c].Code, tree[c].Len); }
1598#endif
1599
1600#define d_code(dist) \
1601   ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
1602/* Mapping from a distance to a distance code. dist is the distance - 1 and
1603 * must not have side effects. dist_code[256] and dist_code[257] are never
1604 * used.
1605 */
1606
1607/* the arguments must not have side effects */
1608
1609/* ===========================================================================
1610 * Allocate the match buffer, initialize the various tables and save the
1611 * location of the internal file attribute (ascii/binary) and method
1612 * (DEFLATE/STORE).
1613 */
1614static void ct_init(ush * attr, int *methodp)
1615{
1616    int n;              /* iterates over tree elements */
1617    int bits;           /* bit counter */
1618    int length;         /* length value */
1619    int code;           /* code value */
1620    int dist;           /* distance index */
1621
1622    file_type = attr;
1623    file_method = methodp;
1624    compressed_len = 0L;
1625
1626    if (static_dtree[0].Len != 0)
1627        return;         /* ct_init already called */
1628
1629    /* Initialize the mapping length (0..255) -> length code (0..28) */
1630    length = 0;
1631    for (code = 0; code < LENGTH_CODES - 1; code++) {
1632        base_length[code] = length;
1633        for (n = 0; n < (1 << extra_lbits[code]); n++) {
1634            length_code[length++] = (uch) code;
1635        }
1636    }
1637    Assert(length == 256, "ct_init: length != 256");
1638    /* Note that the length 255 (match length 258) can be represented
1639     * in two different ways: code 284 + 5 bits or code 285, so we
1640     * overwrite length_code[255] to use the best encoding:
1641     */
1642    length_code[length - 1] = (uch) code;
1643
1644    /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
1645    dist = 0;
1646    for (code = 0; code < 16; code++) {
1647        base_dist[code] = dist;
1648        for (n = 0; n < (1 << extra_dbits[code]); n++) {
1649            dist_code[dist++] = (uch) code;
1650        }
1651    }
1652    Assert(dist == 256, "ct_init: dist != 256");
1653    dist >>= 7;         /* from now on, all distances are divided by 128 */
1654    for (; code < D_CODES; code++) {
1655        base_dist[code] = dist << 7;
1656        for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
1657            dist_code[256 + dist++] = (uch) code;
1658        }
1659    }
1660    Assert(dist == 256, "ct_init: 256+dist != 512");
1661
1662    /* Construct the codes of the static literal tree */
1663    for (bits = 0; bits <= MAX_BITS; bits++)
1664        bl_count[bits] = 0;
1665    n = 0;
1666    while (n <= 143)
1667        static_ltree[n++].Len = 8, bl_count[8]++;
1668    while (n <= 255)
1669        static_ltree[n++].Len = 9, bl_count[9]++;
1670    while (n <= 279)
1671        static_ltree[n++].Len = 7, bl_count[7]++;
1672    while (n <= 287)
1673        static_ltree[n++].Len = 8, bl_count[8]++;
1674    /* Codes 286 and 287 do not exist, but we must include them in the
1675     * tree construction to get a canonical Huffman tree (longest code
1676     * all ones)
1677     */
1678    gen_codes((ct_data *) static_ltree, L_CODES + 1);
1679
1680    /* The static distance tree is trivial: */
1681    for (n = 0; n < D_CODES; n++) {
1682        static_dtree[n].Len = 5;
1683        static_dtree[n].Code = bi_reverse(n, 5);
1684    }
1685
1686    /* Initialize the first block of the first file: */
1687    init_block();
1688}
1689
1690/* ===========================================================================
1691 * Initialize a new block.
1692 */
1693static void init_block(void)
1694{
1695    int n;              /* iterates over tree elements */
1696
1697    /* Initialize the trees. */
1698    for (n = 0; n < L_CODES; n++)
1699        dyn_ltree[n].Freq = 0;
1700    for (n = 0; n < D_CODES; n++)
1701        dyn_dtree[n].Freq = 0;
1702    for (n = 0; n < BL_CODES; n++)
1703        bl_tree[n].Freq = 0;
1704
1705    dyn_ltree[END_BLOCK].Freq = 1;
1706    opt_len = static_len = 0L;
1707    last_lit = last_dist = last_flags = 0;
1708    flags = 0;
1709    flag_bit = 1;
1710}
1711
1712#define SMALLEST 1
1713/* Index within the heap array of least frequent node in the Huffman tree */
1714
1715
1716/* ===========================================================================
1717 * Remove the smallest element from the heap and recreate the heap with
1718 * one less element. Updates heap and heap_len.
1719 */
1720#define pqremove(tree, top) \
1721{\
1722    top = heap[SMALLEST]; \
1723    heap[SMALLEST] = heap[heap_len--]; \
1724    pqdownheap(tree, SMALLEST); \
1725}
1726
1727/* ===========================================================================
1728 * Compares to subtrees, using the tree depth as tie breaker when
1729 * the subtrees have equal frequency. This minimizes the worst case length.
1730 */
1731#define smaller(tree, n, m) \
1732   (tree[n].Freq < tree[m].Freq || \
1733   (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
1734
1735/* ===========================================================================
1736 * Restore the heap property by moving down the tree starting at node k,
1737 * exchanging a node with the smallest of its two sons if necessary, stopping
1738 * when the heap property is re-established (each father smaller than its
1739 * two sons).
1740 */
1741static void pqdownheap(ct_data * tree, int k)
1742{
1743    int v = heap[k];
1744    int j = k << 1;     /* left son of k */
1745
1746    while (j <= heap_len) {
1747        /* Set j to the smallest of the two sons: */
1748        if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
1749            j++;
1750
1751        /* Exit if v is smaller than both sons */
1752        if (smaller(tree, v, heap[j]))
1753            break;
1754
1755        /* Exchange v with the smallest son */
1756        heap[k] = heap[j];
1757        k = j;
1758
1759        /* And continue down the tree, setting j to the left son of k */
1760        j <<= 1;
1761    }
1762    heap[k] = v;
1763}
1764
1765/* ===========================================================================
1766 * Compute the optimal bit lengths for a tree and update the total bit length
1767 * for the current block.
1768 * IN assertion: the fields freq and dad are set, heap[heap_max] and
1769 *    above are the tree nodes sorted by increasing frequency.
1770 * OUT assertions: the field len is set to the optimal bit length, the
1771 *     array bl_count contains the frequencies for each bit length.
1772 *     The length opt_len is updated; static_len is also updated if stree is
1773 *     not null.
1774 */
1775static void gen_bitlen(tree_desc * desc)
1776{
1777    ct_data *tree = desc->dyn_tree;
1778    const extra_bits_t *extra = desc->extra_bits;
1779    int base = desc->extra_base;
1780    int max_code = desc->max_code;
1781    int max_length = desc->max_length;
1782    ct_data *stree = desc->static_tree;
1783    int h;              /* heap index */
1784    int n, m;           /* iterate over the tree elements */
1785    int bits;           /* bit length */
1786    int xbits;          /* extra bits */
1787    ush f;              /* frequency */
1788    int overflow = 0;   /* number of elements with bit length too large */
1789
1790    for (bits = 0; bits <= MAX_BITS; bits++)
1791        bl_count[bits] = 0;
1792
1793    /* In a first pass, compute the optimal bit lengths (which may
1794     * overflow in the case of the bit length tree).
1795     */
1796    tree[heap[heap_max]].Len = 0;   /* root of the heap */
1797
1798    for (h = heap_max + 1; h < HEAP_SIZE; h++) {
1799        n = heap[h];
1800        bits = tree[tree[n].Dad].Len + 1;
1801        if (bits > max_length)
1802            bits = max_length, overflow++;
1803        tree[n].Len = (ush) bits;
1804        /* We overwrite tree[n].Dad which is no longer needed */
1805
1806        if (n > max_code)
1807            continue;   /* not a leaf node */
1808
1809        bl_count[bits]++;
1810        xbits = 0;
1811        if (n >= base)
1812            xbits = extra[n - base];
1813        f = tree[n].Freq;
1814        opt_len += (ulg) f *(bits + xbits);
1815
1816        if (stree)
1817            static_len += (ulg) f *(stree[n].Len + xbits);
1818    }
1819    if (overflow == 0)
1820        return;
1821
1822    Trace((stderr, "\nbit length overflow\n"));
1823    /* This happens for example on obj2 and pic of the Calgary corpus */
1824
1825    /* Find the first bit length which could increase: */
1826    do {
1827        bits = max_length - 1;
1828        while (bl_count[bits] == 0)
1829            bits--;
1830        bl_count[bits]--;   /* move one leaf down the tree */
1831        bl_count[bits + 1] += 2;    /* move one overflow item as its brother */
1832        bl_count[max_length]--;
1833        /* The brother of the overflow item also moves one step up,
1834         * but this does not affect bl_count[max_length]
1835         */
1836        overflow -= 2;
1837    } while (overflow > 0);
1838
1839    /* Now recompute all bit lengths, scanning in increasing frequency.
1840     * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
1841     * lengths instead of fixing only the wrong ones. This idea is taken
1842     * from 'ar' written by Haruhiko Okumura.)
1843     */
1844    for (bits = max_length; bits != 0; bits--) {
1845        n = bl_count[bits];
1846        while (n != 0) {
1847            m = heap[--h];
1848            if (m > max_code)
1849                continue;
1850            if (tree[m].Len != (unsigned) bits) {
1851                Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len,
1852                       bits));
1853                opt_len +=
1854                    ((long) bits - (long) tree[m].Len) * (long) tree[m].Freq;
1855                tree[m].Len = (ush) bits;
1856            }
1857            n--;
1858        }
1859    }
1860}
1861
1862/* ===========================================================================
1863 * Generate the codes for a given tree and bit counts (which need not be
1864 * optimal).
1865 * IN assertion: the array bl_count contains the bit length statistics for
1866 * the given tree and the field len is set for all tree elements.
1867 * OUT assertion: the field code is set for all tree elements of non
1868 *     zero code length.
1869 */
1870static void gen_codes(ct_data * tree, int max_code)
1871{
1872    ush next_code[MAX_BITS + 1];    /* next code value for each bit length */
1873    ush code = 0;       /* running code value */
1874    int bits;           /* bit index */
1875    int n;              /* code index */
1876
1877    /* The distribution counts are first used to generate the code values
1878     * without bit reversal.
1879     */
1880    for (bits = 1; bits <= MAX_BITS; bits++) {
1881        next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
1882    }
1883    /* Check that the bit counts in bl_count are consistent. The last code
1884     * must be all ones.
1885     */
1886    Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1,
1887           "inconsistent bit counts");
1888    Tracev((stderr, "\ngen_codes: max_code %d ", max_code));
1889
1890    for (n = 0; n <= max_code; n++) {
1891        int len = tree[n].Len;
1892
1893        if (len == 0)
1894            continue;
1895        /* Now reverse the bits */
1896        tree[n].Code = bi_reverse(next_code[len]++, len);
1897
1898        Tracec(tree != static_ltree,
1899               (stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
1900                (isgraph(n) ? n : ' '), len, tree[n].Code,
1901                next_code[len] - 1));
1902    }
1903}
1904
1905/* ===========================================================================
1906 * Construct one Huffman tree and assigns the code bit strings and lengths.
1907 * Update the total bit length for the current block.
1908 * IN assertion: the field freq is set for all tree elements.
1909 * OUT assertions: the fields len and code are set to the optimal bit length
1910 *     and corresponding code. The length opt_len is updated; static_len is
1911 *     also updated if stree is not null. The field max_code is set.
1912 */
1913static void build_tree(tree_desc * desc)
1914{
1915    ct_data *tree = desc->dyn_tree;
1916    ct_data *stree = desc->static_tree;
1917    int elems = desc->elems;
1918    int n, m;           /* iterate over heap elements */
1919    int max_code = -1;  /* largest code with non zero frequency */
1920    int node = elems;   /* next internal node of the tree */
1921
1922    /* Construct the initial heap, with least frequent element in
1923     * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
1924     * heap[0] is not used.
1925     */
1926    heap_len = 0, heap_max = HEAP_SIZE;
1927
1928    for (n = 0; n < elems; n++) {
1929        if (tree[n].Freq != 0) {
1930            heap[++heap_len] = max_code = n;
1931            depth[n] = 0;
1932        } else {
1933            tree[n].Len = 0;
1934        }
1935    }
1936
1937    /* The pkzip format requires that at least one distance code exists,
1938     * and that at least one bit should be sent even if there is only one
1939     * possible code. So to avoid special checks later on we force at least
1940     * two codes of non zero frequency.
1941     */
1942    while (heap_len < 2) {
1943        int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
1944
1945        tree[new].Freq = 1;
1946        depth[new] = 0;
1947        opt_len--;
1948        if (stree)
1949            static_len -= stree[new].Len;
1950        /* new is 0 or 1 so it does not have extra bits */
1951    }
1952    desc->max_code = max_code;
1953
1954    /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
1955     * establish sub-heaps of increasing lengths:
1956     */
1957    for (n = heap_len / 2; n >= 1; n--)
1958        pqdownheap(tree, n);
1959
1960    /* Construct the Huffman tree by repeatedly combining the least two
1961     * frequent nodes.
1962     */
1963    do {
1964        pqremove(tree, n);  /* n = node of least frequency */
1965        m = heap[SMALLEST]; /* m = node of next least frequency */
1966
1967        heap[--heap_max] = n;   /* keep the nodes sorted by frequency */
1968        heap[--heap_max] = m;
1969
1970        /* Create a new node father of n and m */
1971        tree[node].Freq = tree[n].Freq + tree[m].Freq;
1972        depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
1973        tree[n].Dad = tree[m].Dad = (ush) node;
1974#ifdef DUMP_BL_TREE
1975        if (tree == bl_tree) {
1976            bb_error_msg("\nnode %d(%d), sons %d(%d) %d(%d)",
1977                    node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
1978        }
1979#endif
1980        /* and insert the new node in the heap */
1981        heap[SMALLEST] = node++;
1982        pqdownheap(tree, SMALLEST);
1983
1984    } while (heap_len >= 2);
1985
1986    heap[--heap_max] = heap[SMALLEST];
1987
1988    /* At this point, the fields freq and dad are set. We can now
1989     * generate the bit lengths.
1990     */
1991    gen_bitlen((tree_desc *) desc);
1992
1993    /* The field len is now set, we can generate the bit codes */
1994    gen_codes((ct_data *) tree, max_code);
1995}
1996
1997/* ===========================================================================
1998 * Scan a literal or distance tree to determine the frequencies of the codes
1999 * in the bit length tree. Updates opt_len to take into account the repeat
2000 * counts. (The contribution of the bit length codes will be added later
2001 * during the construction of bl_tree.)
2002 */
2003static void scan_tree(ct_data * tree, int max_code)
2004{
2005    int n;              /* iterates over all tree elements */
2006    int prevlen = -1;   /* last emitted length */
2007    int curlen;         /* length of current code */
2008    int nextlen = tree[0].Len;  /* length of next code */
2009    int count = 0;      /* repeat count of the current code */
2010    int max_count = 7;  /* max repeat count */
2011    int min_count = 4;  /* min repeat count */
2012
2013    if (nextlen == 0)
2014        max_count = 138, min_count = 3;
2015    tree[max_code + 1].Len = (ush) 0xffff;  /* guard */
2016
2017    for (n = 0; n <= max_code; n++) {
2018        curlen = nextlen;
2019        nextlen = tree[n + 1].Len;
2020        if (++count < max_count && curlen == nextlen) {
2021            continue;
2022        } else if (count < min_count) {
2023            bl_tree[curlen].Freq += count;
2024        } else if (curlen != 0) {
2025            if (curlen != prevlen)
2026                bl_tree[curlen].Freq++;
2027            bl_tree[REP_3_6].Freq++;
2028        } else if (count <= 10) {
2029            bl_tree[REPZ_3_10].Freq++;
2030        } else {
2031            bl_tree[REPZ_11_138].Freq++;
2032        }
2033        count = 0;
2034        prevlen = curlen;
2035        if (nextlen == 0) {
2036            max_count = 138, min_count = 3;
2037        } else if (curlen == nextlen) {
2038            max_count = 6, min_count = 3;
2039        } else {
2040            max_count = 7, min_count = 4;
2041        }
2042    }
2043}
2044
2045/* ===========================================================================
2046 * Send a literal or distance tree in compressed form, using the codes in
2047 * bl_tree.
2048 */
2049static void send_tree(ct_data * tree, int max_code)
2050{
2051    int n;              /* iterates over all tree elements */
2052    int prevlen = -1;   /* last emitted length */
2053    int curlen;         /* length of current code */
2054    int nextlen = tree[0].Len;  /* length of next code */
2055    int count = 0;      /* repeat count of the current code */
2056    int max_count = 7;  /* max repeat count */
2057    int min_count = 4;  /* min repeat count */
2058
2059/* tree[max_code+1].Len = -1; *//* guard already set */
2060    if (nextlen == 0)
2061        max_count = 138, min_count = 3;
2062
2063    for (n = 0; n <= max_code; n++) {
2064        curlen = nextlen;
2065        nextlen = tree[n + 1].Len;
2066        if (++count < max_count && curlen == nextlen) {
2067            continue;
2068        } else if (count < min_count) {
2069            do {
2070                send_code(curlen, bl_tree);
2071            } while (--count != 0);
2072
2073        } else if (curlen != 0) {
2074            if (curlen != prevlen) {
2075                send_code(curlen, bl_tree);
2076                count--;
2077            }
2078            Assert(count >= 3 && count <= 6, " 3_6?");
2079            send_code(REP_3_6, bl_tree);
2080            send_bits(count - 3, 2);
2081
2082        } else if (count <= 10) {
2083            send_code(REPZ_3_10, bl_tree);
2084            send_bits(count - 3, 3);
2085
2086        } else {
2087            send_code(REPZ_11_138, bl_tree);
2088            send_bits(count - 11, 7);
2089        }
2090        count = 0;
2091        prevlen = curlen;
2092        if (nextlen == 0) {
2093            max_count = 138, min_count = 3;
2094        } else if (curlen == nextlen) {
2095            max_count = 6, min_count = 3;
2096        } else {
2097            max_count = 7, min_count = 4;
2098        }
2099    }
2100}
2101
2102/* ===========================================================================
2103 * Construct the Huffman tree for the bit lengths and return the index in
2104 * bl_order of the last bit length code to send.
2105 */
2106static int build_bl_tree(void)
2107{
2108    int max_blindex;    /* index of last bit length code of non zero freq */
2109
2110    /* Determine the bit length frequencies for literal and distance trees */
2111    scan_tree((ct_data *) dyn_ltree, l_desc.max_code);
2112    scan_tree((ct_data *) dyn_dtree, d_desc.max_code);
2113
2114    /* Build the bit length tree: */
2115    build_tree((tree_desc *) (&bl_desc));
2116    /* opt_len now includes the length of the tree representations, except
2117     * the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
2118     */
2119
2120    /* Determine the number of bit length codes to send. The pkzip format
2121     * requires that at least 4 bit length codes be sent. (appnote.txt says
2122     * 3 but the actual value used is 4.)
2123     */
2124    for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) {
2125        if (bl_tree[bl_order[max_blindex]].Len != 0)
2126            break;
2127    }
2128    /* Update opt_len to include the bit length tree and counts */
2129    opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
2130    Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
2131
2132    return max_blindex;
2133}
2134
2135/* ===========================================================================
2136 * Send the header for a block using dynamic Huffman trees: the counts, the
2137 * lengths of the bit length codes, the literal tree and the distance tree.
2138 * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
2139 */
2140static void send_all_trees(int lcodes, int dcodes, int blcodes)
2141{
2142    int rank;           /* index in bl_order */
2143
2144    Assert(lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
2145    Assert(lcodes <= L_CODES && dcodes <= D_CODES
2146           && blcodes <= BL_CODES, "too many codes");
2147    Tracev((stderr, "\nbl counts: "));
2148    send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */
2149    send_bits(dcodes - 1, 5);
2150    send_bits(blcodes - 4, 4);  /* not -3 as stated in appnote.txt */
2151    for (rank = 0; rank < blcodes; rank++) {
2152        Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
2153        send_bits(bl_tree[bl_order[rank]].Len, 3);
2154    }
2155    Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
2156
2157    send_tree((ct_data *) dyn_ltree, lcodes - 1);   /* send the literal tree */
2158    Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
2159
2160    send_tree((ct_data *) dyn_dtree, dcodes - 1);   /* send the distance tree */
2161    Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
2162}
2163
2164/* ===========================================================================
2165 * Determine the best encoding for the current block: dynamic trees, static
2166 * trees or store, and output the encoded block to the zip file. This function
2167 * returns the total compressed length for the file so far.
2168 */
2169static ulg flush_block(char *buf, ulg stored_len, int eof)
2170{
2171    ulg opt_lenb, static_lenb;  /* opt_len and static_len in bytes */
2172    int max_blindex;    /* index of last bit length code of non zero freq */
2173
2174    flag_buf[last_flags] = flags;   /* Save the flags for the last 8 items */
2175
2176    /* Check if the file is ascii or binary */
2177    if (*file_type == (ush) UNKNOWN)
2178        set_file_type();
2179
2180    /* Construct the literal and distance trees */
2181    build_tree((tree_desc *) (&l_desc));
2182    Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
2183
2184    build_tree((tree_desc *) (&d_desc));
2185    Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
2186    /* At this point, opt_len and static_len are the total bit lengths of
2187     * the compressed block data, excluding the tree representations.
2188     */
2189
2190    /* Build the bit length tree for the above two trees, and get the index
2191     * in bl_order of the last bit length code to send.
2192     */
2193    max_blindex = build_bl_tree();
2194
2195    /* Determine the best encoding. Compute first the block length in bytes */
2196    opt_lenb = (opt_len + 3 + 7) >> 3;
2197    static_lenb = (static_len + 3 + 7) >> 3;
2198
2199    Trace((stderr,
2200           "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
2201           opt_lenb, opt_len, static_lenb, static_len, stored_len,
2202           last_lit, last_dist));
2203
2204    if (static_lenb <= opt_lenb)
2205        opt_lenb = static_lenb;
2206
2207    /* If compression failed and this is the first and last block,
2208     * and if the zip file can be seeked (to rewrite the local header),
2209     * the whole file is transformed into a stored file:
2210     */
2211    if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
2212        /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
2213        if (buf == (char *) 0)
2214            bb_error_msg("block vanished");
2215
2216        copy_block(buf, (unsigned) stored_len, 0);  /* without header */
2217        compressed_len = stored_len << 3;
2218        *file_method = STORED;
2219
2220    } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
2221        /* 4: two words for the lengths */
2222        /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
2223         * Otherwise we can't have processed more than WSIZE input bytes since
2224         * the last block flush, because compression would have been
2225         * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
2226         * transform a block into a stored block.
2227         */
2228        send_bits((STORED_BLOCK << 1) + eof, 3);    /* send block type */
2229        compressed_len = (compressed_len + 3 + 7) & ~7L;
2230        compressed_len += (stored_len + 4) << 3;
2231
2232        copy_block(buf, (unsigned) stored_len, 1);  /* with header */
2233
2234    } else if (static_lenb == opt_lenb) {
2235        send_bits((STATIC_TREES << 1) + eof, 3);
2236        compress_block((ct_data *) static_ltree, (ct_data *) static_dtree);
2237        compressed_len += 3 + static_len;
2238    } else {
2239        send_bits((DYN_TREES << 1) + eof, 3);
2240        send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1,
2241                       max_blindex + 1);
2242        compress_block((ct_data *) dyn_ltree, (ct_data *) dyn_dtree);
2243        compressed_len += 3 + opt_len;
2244    }
2245    Assert(compressed_len == bits_sent, "bad compressed size");
2246    init_block();
2247
2248    if (eof) {
2249        bi_windup();
2250        compressed_len += 7;    /* align on byte boundary */
2251    }
2252    Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
2253            compressed_len - 7 * eof));
2254
2255    return compressed_len >> 3;
2256}
2257
2258/* ===========================================================================
2259 * Save the match info and tally the frequency counts. Return true if
2260 * the current block must be flushed.
2261 */
2262static int ct_tally(int dist, int lc)
2263{
2264    l_buf[last_lit++] = (uch) lc;
2265    if (dist == 0) {
2266        /* lc is the unmatched char */
2267        dyn_ltree[lc].Freq++;
2268    } else {
2269        /* Here, lc is the match length - MIN_MATCH */
2270        dist--;         /* dist = match distance - 1 */
2271        Assert((ush) dist < (ush) MAX_DIST &&
2272               (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) &&
2273               (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match");
2274
2275        dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
2276        dyn_dtree[d_code(dist)].Freq++;
2277
2278        d_buf[last_dist++] = (ush) dist;
2279        flags |= flag_bit;
2280    }
2281    flag_bit <<= 1;
2282
2283    /* Output the flags if they fill a byte: */
2284    if ((last_lit & 7) == 0) {
2285        flag_buf[last_flags++] = flags;
2286        flags = 0, flag_bit = 1;
2287    }
2288    /* Try to guess if it is profitable to stop the current block here */
2289    if ((last_lit & 0xfff) == 0) {
2290        /* Compute an upper bound for the compressed length */
2291        ulg out_length = (ulg) last_lit * 8L;
2292        ulg in_length = (ulg) strstart - block_start;
2293        int dcode;
2294
2295        for (dcode = 0; dcode < D_CODES; dcode++) {
2296            out_length +=
2297                (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
2298        }
2299        out_length >>= 3;
2300        Trace((stderr,
2301               "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
2302               last_lit, last_dist, in_length, out_length,
2303               100L - out_length * 100L / in_length));
2304        if (last_dist < last_lit / 2 && out_length < in_length / 2)
2305            return 1;
2306    }
2307    return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE);
2308    /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
2309     * on 16 bit machines and because stored blocks are restricted to
2310     * 64K-1 bytes.
2311     */
2312}
2313
2314/* ===========================================================================
2315 * Send the block data compressed using the given Huffman trees
2316 */
2317static void compress_block(ct_data * ltree, ct_data * dtree)
2318{
2319    unsigned dist;      /* distance of matched string */
2320    int lc;             /* match length or unmatched char (if dist == 0) */
2321    unsigned lx = 0;    /* running index in l_buf */
2322    unsigned dx = 0;    /* running index in d_buf */
2323    unsigned fx = 0;    /* running index in flag_buf */
2324    uch flag = 0;       /* current flags */
2325    unsigned code;      /* the code to send */
2326    int extra;          /* number of extra bits to send */
2327
2328    if (last_lit != 0)
2329        do {
2330            if ((lx & 7) == 0)
2331                flag = flag_buf[fx++];
2332            lc = l_buf[lx++];
2333            if ((flag & 1) == 0) {
2334                send_code(lc, ltree);   /* send a literal byte */
2335                Tracecv(isgraph(lc), (stderr, " '%c' ", lc));
2336            } else {
2337                /* Here, lc is the match length - MIN_MATCH */
2338                code = length_code[lc];
2339                send_code(code + LITERALS + 1, ltree);  /* send the length code */
2340                extra = extra_lbits[code];
2341                if (extra != 0) {
2342                    lc -= base_length[code];
2343                    send_bits(lc, extra);   /* send the extra length bits */
2344                }
2345                dist = d_buf[dx++];
2346                /* Here, dist is the match distance - 1 */
2347                code = d_code(dist);
2348                Assert(code < D_CODES, "bad d_code");
2349
2350                send_code(code, dtree); /* send the distance code */
2351                extra = extra_dbits[code];
2352                if (extra != 0) {
2353                    dist -= base_dist[code];
2354                    send_bits(dist, extra); /* send the extra distance bits */
2355                }
2356            }           /* literal or match pair ? */
2357            flag >>= 1;
2358        } while (lx < last_lit);
2359
2360    send_code(END_BLOCK, ltree);
2361}
2362
2363/* ===========================================================================
2364 * Set the file type to ASCII or BINARY, using a crude approximation:
2365 * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
2366 * IN assertion: the fields freq of dyn_ltree are set and the total of all
2367 * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
2368 */
2369static void set_file_type(void)
2370{
2371    int n = 0;
2372    unsigned ascii_freq = 0;
2373    unsigned bin_freq = 0;
2374
2375    while (n < 7)
2376        bin_freq += dyn_ltree[n++].Freq;
2377    while (n < 128)
2378        ascii_freq += dyn_ltree[n++].Freq;
2379    while (n < LITERALS)
2380        bin_freq += dyn_ltree[n++].Freq;
2381    *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
2382    if (*file_type == BINARY && translate_eol) {
2383        bb_error_msg("-l used on binary file");
2384    }
2385}
2386
2387/* zip.c -- compress files to the gzip or pkzip format
2388 * Copyright (C) 1992-1993 Jean-loup Gailly
2389 * This is free software; you can redistribute it and/or modify it under the
2390 * terms of the GNU General Public License, see the file COPYING.
2391 */
2392
2393
2394static uint32_t crc;            /* crc on uncompressed file data */
2395static long header_bytes;   /* number of bytes in gzip header */
2396
2397static void put_long(ulg n)
2398{
2399    put_short((n) & 0xffff);
2400    put_short(((ulg) (n)) >> 16);
2401}
2402
2403/* put_header_byte is used for the compressed output
2404 * - for the initial 4 bytes that can't overflow the buffer.
2405 */
2406#define put_header_byte(c) {outbuf[outcnt++]=(uch)(c);}
2407
2408/* ===========================================================================
2409 * Deflate in to out.
2410 * IN assertions: the input and output buffers are cleared.
2411 *   The variables time_stamp and save_orig_name are initialized.
2412 */
2413static int zip(int in, int out)
2414{
2415    uch my_flags = 0;   /* general purpose bit flags */
2416    ush attr = 0;       /* ascii/binary flag */
2417    ush deflate_flags = 0;  /* pkzip -es, -en or -ex equivalent */
2418
2419    ifd = in;
2420    ofd = out;
2421    outcnt = 0;
2422
2423    /* Write the header to the gzip file. See algorithm.doc for the format */
2424
2425
2426    method = DEFLATED;
2427    put_header_byte(GZIP_MAGIC[0]); /* magic header */
2428    put_header_byte(GZIP_MAGIC[1]);
2429    put_header_byte(DEFLATED);  /* compression method */
2430
2431    put_header_byte(my_flags);  /* general flags */
2432    put_long(time_stamp);
2433
2434    /* Write deflated file to zip file */
2435    crc = updcrc(0, 0);
2436
2437    bi_init(out);
2438    ct_init(&attr, &method);
2439    lm_init(&deflate_flags);
2440
2441    put_byte((uch) deflate_flags);  /* extra flags */
2442    put_byte(OS_CODE);  /* OS identifier */
2443
2444    header_bytes = (long) outcnt;
2445
2446    (void) deflate();
2447
2448    /* Write the crc and uncompressed size */
2449    put_long(crc);
2450    put_long(isize);
2451    header_bytes += 2 * sizeof(long);
2452
2453    flush_outbuf();
2454    return OK;
2455}
2456
2457
2458/* ===========================================================================
2459 * Read a new buffer from the current input file, perform end-of-line
2460 * translation, and update the crc and input file size.
2461 * IN assertion: size >= 2 (for end-of-line translation)
2462 */
2463static int file_read(char *buf, unsigned size)
2464{
2465    unsigned len;
2466
2467    Assert(insize == 0, "inbuf not empty");
2468
2469    len = read(ifd, buf, size);
2470    if (len == (unsigned) (-1) || len == 0)
2471        return (int) len;
2472
2473    crc = updcrc((uch *) buf, len);
2474    isize += (ulg) len;
2475    return (int) len;
2476}
2477
2478/* ===========================================================================
2479 * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
2480 * (used for the compressed data only)
2481 */
2482static void flush_outbuf(void)
2483{
2484    if (outcnt == 0)
2485        return;
2486
2487    write_buf(ofd, (char *) outbuf, outcnt);
2488    outcnt = 0;
2489}
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