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Diffstat (limited to 'release/src/router/busybox/gzip.c')
| -rw-r--r-- | release/src/router/busybox/gzip.c | 2550 |
1 files changed, 0 insertions, 2550 deletions
diff --git a/release/src/router/busybox/gzip.c b/release/src/router/busybox/gzip.c deleted file mode 100644 index 54bb7274..00000000 --- a/release/src/router/busybox/gzip.c +++ /dev/null @@ -1,2550 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * Gzip implementation for busybox - * - * Based on GNU gzip Copyright (C) 1992-1993 Jean-loup Gailly. - * - * Originally adjusted for busybox by Charles P. Wright <cpw@unix.asb.com> - * "this is a stripped down version of gzip I put into busybox, it does - * only standard in to standard out with -9 compression. It also requires - * the zcat module for some important functions." - * - * Adjusted further by Erik Andersen <andersen@lineo.com>, <andersee@debian.org> - * to support files as well as stdin/stdout, and to generally behave itself wrt - * command line handling. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * - */ - -/* These defines are very important for BusyBox. Without these, - * huge chunks of ram are pre-allocated making the BusyBox bss - * size Freaking Huge(tm), which is a bad thing.*/ -#define SMALL_MEM -#define DYN_ALLOC - -#include <stdlib.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> -#include <errno.h> -#include <sys/types.h> -#include <signal.h> -#include <utime.h> -#include <ctype.h> -#include <sys/types.h> -#include <unistd.h> -#include <dirent.h> -#include <fcntl.h> -#include <time.h> -#include "busybox.h" - -#define memzero(s, n) memset ((void *)(s), 0, (n)) - -#ifndef RETSIGTYPE -# define RETSIGTYPE void -#endif - -typedef unsigned char uch; -typedef unsigned short ush; -typedef unsigned long ulg; - -/* Return codes from gzip */ -#define OK 0 -#define ERROR 1 -#define WARNING 2 - -/* Compression methods (see algorithm.doc) */ -/* Only STORED and DEFLATED are supported by this BusyBox module */ -#define STORED 0 -/* methods 4 to 7 reserved */ -#define DEFLATED 8 -static int method; /* compression method */ - -/* To save memory for 16 bit systems, some arrays are overlaid between - * the various modules: - * deflate: prev+head window d_buf l_buf outbuf - * unlzw: tab_prefix tab_suffix stack inbuf outbuf - * For compression, input is done in window[]. For decompression, output - * is done in window except for unlzw. - */ - -#ifndef INBUFSIZ -# ifdef SMALL_MEM -# define INBUFSIZ 0x2000 /* input buffer size */ -# else -# define INBUFSIZ 0x8000 /* input buffer size */ -# endif -#endif -#define INBUF_EXTRA 64 /* required by unlzw() */ - -#ifndef OUTBUFSIZ -# ifdef SMALL_MEM -# define OUTBUFSIZ 8192 /* output buffer size */ -# else -# define OUTBUFSIZ 16384 /* output buffer size */ -# endif -#endif -#define OUTBUF_EXTRA 2048 /* required by unlzw() */ - -#ifndef DIST_BUFSIZE -# ifdef SMALL_MEM -# define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */ -# else -# define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */ -# endif -#endif - -#ifdef DYN_ALLOC -# define DECLARE(type, array, size) static type * array -# define ALLOC(type, array, size) { \ - array = (type*)calloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \ - if (array == NULL) error_msg(memory_exhausted); \ - } -# define FREE(array) {if (array != NULL) free(array), array=NULL;} -#else -# define DECLARE(type, array, size) static type array[size] -# define ALLOC(type, array, size) -# define FREE(array) -#endif - -#define tab_suffix window -#define tab_prefix prev /* hash link (see deflate.c) */ -#define head (prev+WSIZE) /* hash head (see deflate.c) */ - -static long bytes_in; /* number of input bytes */ - -#define isize bytes_in -/* for compatibility with old zip sources (to be cleaned) */ - -typedef int file_t; /* Do not use stdio */ - -#define NO_FILE (-1) /* in memory compression */ - - -#define PACK_MAGIC "\037\036" /* Magic header for packed files */ -#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */ -#define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */ -#define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files */ -#define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */ - -/* gzip flag byte */ -#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ -#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ -#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ -#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ -#define COMMENT 0x10 /* bit 4 set: file comment present */ -#define RESERVED 0xC0 /* bit 6,7: reserved */ - -/* internal file attribute */ -#define UNKNOWN 0xffff -#define BINARY 0 -#define ASCII 1 - -#ifndef WSIZE -# define WSIZE 0x8000 /* window size--must be a power of two, and */ -#endif /* at least 32K for zip's deflate method */ - -#define MIN_MATCH 3 -#define MAX_MATCH 258 -/* The minimum and maximum match lengths */ - -#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) -/* Minimum amount of lookahead, except at the end of the input file. - * See deflate.c for comments about the MIN_MATCH+1. - */ - -#define MAX_DIST (WSIZE-MIN_LOOKAHEAD) -/* In order to simplify the code, particularly on 16 bit machines, match - * distances are limited to MAX_DIST instead of WSIZE. - */ - -/* put_byte is used for the compressed output */ -#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\ - flush_outbuf();} - -/* Output a 16 bit value, lsb first */ -#define put_short(w) \ -{ if (outcnt < OUTBUFSIZ-2) { \ - outbuf[outcnt++] = (uch) ((w) & 0xff); \ - outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \ - } else { \ - put_byte((uch)((w) & 0xff)); \ - put_byte((uch)((ush)(w) >> 8)); \ - } \ -} - -/* Output a 32 bit value to the bit stream, lsb first */ -#define put_long(n) { \ - put_short((n) & 0xffff); \ - put_short(((ulg)(n)) >> 16); \ -} - -#define seekable() 0 /* force sequential output */ -#define translate_eol 0 /* no option -a yet */ - -/* Diagnostic functions */ -#ifdef DEBUG -# define Assert(cond,msg) {if(!(cond)) error_msg(msg);} -# define Trace(x) fprintf x -# define Tracev(x) {if (verbose) fprintf x ;} -# define Tracevv(x) {if (verbose>1) fprintf x ;} -# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} -# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} -#else -# define Assert(cond,msg) -# define Trace(x) -# define Tracev(x) -# define Tracevv(x) -# define Tracec(c,x) -# define Tracecv(c,x) -#endif - -#define WARN(msg) {if (!quiet) fprintf msg ; \ - if (exit_code == OK) exit_code = WARNING;} - -#ifndef MAX_PATH_LEN -# define MAX_PATH_LEN 1024 /* max pathname length */ -#endif - - - - /* from zip.c: */ -static int zip (int in, int out); -static int file_read (char *buf, unsigned size); - - /* from gzip.c */ -static RETSIGTYPE abort_gzip (void); - - /* from deflate.c */ -static void lm_init (ush * flags); -static ulg deflate (void); - - /* from trees.c */ -static void ct_init (ush * attr, int *methodp); -static int ct_tally (int dist, int lc); -static ulg flush_block (char *buf, ulg stored_len, int eof); - - /* from bits.c */ -static void bi_init (file_t zipfile); -static void send_bits (int value, int length); -static unsigned bi_reverse (unsigned value, int length); -static void bi_windup (void); -static void copy_block (char *buf, unsigned len, int header); -static int (*read_buf) (char *buf, unsigned size); - - /* from util.c: */ -static void flush_outbuf (void); - -/* lzw.h -- define the lzw functions. - * Copyright (C) 1992-1993 Jean-loup Gailly. - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - -#if !defined(OF) && defined(lint) -# include "gzip.h" -#endif - -#ifndef BITS -# define BITS 16 -#endif -#define INIT_BITS 9 /* Initial number of bits per code */ - -#define BIT_MASK 0x1f /* Mask for 'number of compression bits' */ -/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free. - * It's a pity that old uncompress does not check bit 0x20. That makes - * extension of the format actually undesirable because old compress - * would just crash on the new format instead of giving a meaningful - * error message. It does check the number of bits, but it's more - * helpful to say "unsupported format, get a new version" than - * "can only handle 16 bits". - */ - -/* tailor.h -- target dependent definitions - * Copyright (C) 1992-1993 Jean-loup Gailly. - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - -/* The target dependent definitions should be defined here only. - * The target dependent functions should be defined in tailor.c. - */ - - - /* Common defaults */ - -#ifndef OS_CODE -# define OS_CODE 0x03 /* assume Unix */ -#endif - -#ifndef PATH_SEP -# define PATH_SEP '/' -#endif - -#ifndef OPTIONS_VAR -# define OPTIONS_VAR "GZIP" -#endif - -#ifndef Z_SUFFIX -# define Z_SUFFIX ".gz" -#endif - -#ifdef MAX_EXT_CHARS -# define MAX_SUFFIX MAX_EXT_CHARS -#else -# define MAX_SUFFIX 30 -#endif - - /* global buffers */ - -DECLARE(uch, inbuf, INBUFSIZ + INBUF_EXTRA); -DECLARE(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA); -DECLARE(ush, d_buf, DIST_BUFSIZE); -DECLARE(uch, window, 2L * WSIZE); -DECLARE(ush, tab_prefix, 1L << BITS); - -static int crc_table_empty = 1; - -static int foreground; /* set if program run in foreground */ -static int method = DEFLATED; /* compression method */ -static int exit_code = OK; /* program exit code */ -static int part_nb; /* number of parts in .gz file */ -static long time_stamp; /* original time stamp (modification time) */ -static long ifile_size; /* input file size, -1 for devices (debug only) */ -static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */ -static int z_len; /* strlen(z_suffix) */ - -static char ifname[MAX_PATH_LEN]; /* input file name */ -static char ofname[MAX_PATH_LEN]; /* output file name */ -static int ifd; /* input file descriptor */ -static int ofd; /* output file descriptor */ -static unsigned insize; /* valid bytes in inbuf */ -static unsigned outcnt; /* bytes in output buffer */ - -/* ======================================================================== - * Signal and error handler. - */ -static void abort_gzip() -{ - exit(ERROR); -} - -/* =========================================================================== - * Clear input and output buffers - */ -static void clear_bufs(void) -{ - outcnt = 0; - insize = 0; - bytes_in = 0L; -} - -static void write_error_msg() -{ - fprintf(stderr, "\n"); - perror(""); - abort_gzip(); -} - -/* =========================================================================== - * Does the same as write(), but also handles partial pipe writes and checks - * for error return. - */ -static void write_buf(int fd, void *buf, unsigned cnt) -{ - unsigned n; - - while ((n = write(fd, buf, cnt)) != cnt) { - if (n == (unsigned) (-1)) { - write_error_msg(); - } - cnt -= n; - buf = (void *) ((char *) buf + n); - } -} - -/* =========================================================================== - * Run a set of bytes through the crc shift register. If s is a NULL - * pointer, then initialize the crc shift register contents instead. - * Return the current crc in either case. - */ -static ulg updcrc(uch *s, unsigned n) -{ - static ulg crc = (ulg) 0xffffffffL; /* shift register contents */ - register ulg c; /* temporary variable */ - static unsigned long crc_32_tab[256]; - if (crc_table_empty) { - unsigned long csr; /* crc shift register */ - unsigned long e=0; /* polynomial exclusive-or pattern */ - int i; /* counter for all possible eight bit values */ - int k; /* byte being shifted into crc apparatus */ - - /* terms of polynomial defining this crc (except x^32): */ - static const int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26}; - - /* Make exclusive-or pattern from polynomial (0xedb88320) */ - for (i = 0; i < sizeof(p)/sizeof(int); i++) - e |= 1L << (31 - p[i]); - - /* Compute and print table of CRC's, five per line */ - crc_32_tab[0] = 0x00000000L; - for (i = 1; i < 256; i++) { - csr = i; - /* The idea to initialize the register with the byte instead of - * zero was stolen from Haruhiko Okumura's ar002 - */ - for (k = 8; k; k--) - csr = csr & 1 ? (csr >> 1) ^ e : csr >> 1; - crc_32_tab[i]=csr; - } - } - - if (s == NULL) { - c = 0xffffffffL; - } else { - c = crc; - if (n) - do { - c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8); - } while (--n); - } - crc = c; - return c ^ 0xffffffffL; /* (instead of ~c for 64-bit machines) */ -} - -/* bits.c -- output variable-length bit strings - * Copyright (C) 1992-1993 Jean-loup Gailly - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - - -/* - * PURPOSE - * - * Output variable-length bit strings. Compression can be done - * to a file or to memory. (The latter is not supported in this version.) - * - * DISCUSSION - * - * The PKZIP "deflate" file format interprets compressed file data - * as a sequence of bits. Multi-bit strings in the file may cross - * byte boundaries without restriction. - * - * The first bit of each byte is the low-order bit. - * - * The routines in this file allow a variable-length bit value to - * be output right-to-left (useful for literal values). For - * left-to-right output (useful for code strings from the tree routines), - * the bits must have been reversed first with bi_reverse(). - * - * For in-memory compression, the compressed bit stream goes directly - * into the requested output buffer. The input data is read in blocks - * by the mem_read() function. The buffer is limited to 64K on 16 bit - * machines. - * - * INTERFACE - * - * void bi_init (FILE *zipfile) - * Initialize the bit string routines. - * - * void send_bits (int value, int length) - * Write out a bit string, taking the source bits right to - * left. - * - * int bi_reverse (int value, int length) - * Reverse the bits of a bit string, taking the source bits left to - * right and emitting them right to left. - * - * void bi_windup (void) - * Write out any remaining bits in an incomplete byte. - * - * void copy_block(char *buf, unsigned len, int header) - * Copy a stored block to the zip file, storing first the length and - * its one's complement if requested. - * - */ - -/* =========================================================================== - * Local data used by the "bit string" routines. - */ - -static file_t zfile; /* output gzip file */ - -static unsigned short bi_buf; - -/* Output buffer. bits are inserted starting at the bottom (least significant - * bits). - */ - -#define Buf_size (8 * 2*sizeof(char)) -/* Number of bits used within bi_buf. (bi_buf might be implemented on - * more than 16 bits on some systems.) - */ - -static int bi_valid; - -/* Current input function. Set to mem_read for in-memory compression */ - -#ifdef DEBUG -ulg bits_sent; /* bit length of the compressed data */ -#endif - -/* =========================================================================== - * Initialize the bit string routines. - */ -static void bi_init(file_t zipfile) -{ - zfile = zipfile; - bi_buf = 0; - bi_valid = 0; -#ifdef DEBUG - bits_sent = 0L; -#endif - - /* Set the defaults for file compression. They are set by memcompress - * for in-memory compression. - */ - if (zfile != NO_FILE) { - read_buf = file_read; - } -} - -/* =========================================================================== - * Send a value on a given number of bits. - * IN assertion: length <= 16 and value fits in length bits. - */ -static void send_bits(int value, int length) -{ -#ifdef DEBUG - Tracev((stderr, " l %2d v %4x ", length, value)); - Assert(length > 0 && length <= 15, "invalid length"); - bits_sent += (ulg) length; -#endif - /* If not enough room in bi_buf, use (valid) bits from bi_buf and - * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) - * unused bits in value. - */ - if (bi_valid > (int) Buf_size - length) { - bi_buf |= (value << bi_valid); - put_short(bi_buf); - bi_buf = (ush) value >> (Buf_size - bi_valid); - bi_valid += length - Buf_size; - } else { - bi_buf |= value << bi_valid; - bi_valid += length; - } -} - -/* =========================================================================== - * Reverse the first len bits of a code, using straightforward code (a faster - * method would use a table) - * IN assertion: 1 <= len <= 15 - */ -static unsigned bi_reverse(unsigned code, int len) -{ - register unsigned res = 0; - - do { - res |= code & 1; - code >>= 1, res <<= 1; - } while (--len > 0); - return res >> 1; -} - -/* =========================================================================== - * Write out any remaining bits in an incomplete byte. - */ -static void bi_windup() -{ - if (bi_valid > 8) { - put_short(bi_buf); - } else if (bi_valid > 0) { - put_byte(bi_buf); - } - bi_buf = 0; - bi_valid = 0; -#ifdef DEBUG - bits_sent = (bits_sent + 7) & ~7; -#endif -} - -/* =========================================================================== - * Copy a stored block to the zip file, storing first the length and its - * one's complement if requested. - */ -static void copy_block(char *buf, unsigned len, int header) -{ - bi_windup(); /* align on byte boundary */ - - if (header) { - put_short((ush) len); - put_short((ush) ~ len); -#ifdef DEBUG - bits_sent += 2 * 16; -#endif - } -#ifdef DEBUG - bits_sent += (ulg) len << 3; -#endif - while (len--) { - put_byte(*buf++); - } -} - -/* deflate.c -- compress data using the deflation algorithm - * Copyright (C) 1992-1993 Jean-loup Gailly - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - -/* - * PURPOSE - * - * Identify new text as repetitions of old text within a fixed- - * length sliding window trailing behind the new text. - * - * DISCUSSION - * - * The "deflation" process depends on being able to identify portions - * of the input text which are identical to earlier input (within a - * sliding window trailing behind the input currently being processed). - * - * The most straightforward technique turns out to be the fastest for - * most input files: try all possible matches and select the longest. - * The key feature of this algorithm is that insertions into the string - * dictionary are very simple and thus fast, and deletions are avoided - * completely. Insertions are performed at each input character, whereas - * string matches are performed only when the previous match ends. So it - * is preferable to spend more time in matches to allow very fast string - * insertions and avoid deletions. The matching algorithm for small - * strings is inspired from that of Rabin & Karp. A brute force approach - * is used to find longer strings when a small match has been found. - * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze - * (by Leonid Broukhis). - * A previous version of this file used a more sophisticated algorithm - * (by Fiala and Greene) which is guaranteed to run in linear amortized - * time, but has a larger average cost, uses more memory and is patented. - * However the F&G algorithm may be faster for some highly redundant - * files if the parameter max_chain_length (described below) is too large. - * - * ACKNOWLEDGEMENTS - * - * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and - * I found it in 'freeze' written by Leonid Broukhis. - * Thanks to many info-zippers for bug reports and testing. - * - * REFERENCES - * - * APPNOTE.TXT documentation file in PKZIP 1.93a distribution. - * - * A description of the Rabin and Karp algorithm is given in the book - * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. - * - * Fiala,E.R., and Greene,D.H. - * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 - * - * INTERFACE - * - * void lm_init (int pack_level, ush *flags) - * Initialize the "longest match" routines for a new file - * - * ulg deflate (void) - * Processes a new input file and return its compressed length. Sets - * the compressed length, crc, deflate flags and internal file - * attributes. - */ - - -/* =========================================================================== - * Configuration parameters - */ - -/* Compile with MEDIUM_MEM to reduce the memory requirements or - * with SMALL_MEM to use as little memory as possible. Use BIG_MEM if the - * entire input file can be held in memory (not possible on 16 bit systems). - * Warning: defining these symbols affects HASH_BITS (see below) and thus - * affects the compression ratio. The compressed output - * is still correct, and might even be smaller in some cases. - */ - -#ifdef SMALL_MEM -# define HASH_BITS 13 /* Number of bits used to hash strings */ -#endif -#ifdef MEDIUM_MEM -# define HASH_BITS 14 -#endif -#ifndef HASH_BITS -# define HASH_BITS 15 - /* For portability to 16 bit machines, do not use values above 15. */ -#endif - -/* To save space (see unlzw.c), we overlay prev+head with tab_prefix and - * window with tab_suffix. Check that we can do this: - */ -#if (WSIZE<<1) > (1<<BITS) -# error cannot overlay window with tab_suffix and prev with tab_prefix0 -#endif -#if HASH_BITS > BITS-1 -# error cannot overlay head with tab_prefix1 -#endif -#define HASH_SIZE (unsigned)(1<<HASH_BITS) -#define HASH_MASK (HASH_SIZE-1) -#define WMASK (WSIZE-1) -/* HASH_SIZE and WSIZE must be powers of two */ -#define NIL 0 -/* Tail of hash chains */ -#define FAST 4 -#define SLOW 2 -/* speed options for the general purpose bit flag */ -#ifndef TOO_FAR -# define TOO_FAR 4096 -#endif -/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ -/* =========================================================================== - * Local data used by the "longest match" routines. - */ -typedef ush Pos; -typedef unsigned IPos; - -/* A Pos is an index in the character window. We use short instead of int to - * save space in the various tables. IPos is used only for parameter passing. - */ - -/* DECLARE(uch, window, 2L*WSIZE); */ -/* Sliding window. Input bytes are read into the second half of the window, - * and move to the first half later to keep a dictionary of at least WSIZE - * bytes. With this organization, matches are limited to a distance of - * WSIZE-MAX_MATCH bytes, but this ensures that IO is always - * performed with a length multiple of the block size. Also, it limits - * the window size to 64K, which is quite useful on MSDOS. - * To do: limit the window size to WSIZE+BSZ if SMALL_MEM (the code would - * be less efficient). - */ - -/* DECLARE(Pos, prev, WSIZE); */ -/* Link to older string with same hash index. To limit the size of this - * array to 64K, this link is maintained only for the last 32K strings. - * An index in this array is thus a window index modulo 32K. - */ - -/* DECLARE(Pos, head, 1<<HASH_BITS); */ -/* Heads of the hash chains or NIL. */ - -static const ulg window_size = (ulg) 2 * WSIZE; - -/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the - * input file length plus MIN_LOOKAHEAD. - */ - -static long block_start; - -/* window position at the beginning of the current output block. Gets - * negative when the window is moved backwards. - */ - -static unsigned ins_h; /* hash index of string to be inserted */ - -#define H_SHIFT ((HASH_BITS+MIN_MATCH-1)/MIN_MATCH) -/* Number of bits by which ins_h and del_h must be shifted at each - * input step. It must be such that after MIN_MATCH steps, the oldest - * byte no longer takes part in the hash key, that is: - * H_SHIFT * MIN_MATCH >= HASH_BITS - */ - -static unsigned int prev_length; - -/* Length of the best match at previous step. Matches not greater than this - * are discarded. This is used in the lazy match evaluation. - */ - -static unsigned strstart; /* start of string to insert */ -static unsigned match_start; /* start of matching string */ -static int eofile; /* flag set at end of input file */ -static unsigned lookahead; /* number of valid bytes ahead in window */ - -static const unsigned max_chain_length=4096; - -/* To speed up deflation, hash chains are never searched beyond this length. - * A higher limit improves compression ratio but degrades the speed. - */ - -static const unsigned int max_lazy_match=258; - -/* Attempt to find a better match only when the current match is strictly - * smaller than this value. This mechanism is used only for compression - * levels >= 4. - */ -#define max_insert_length max_lazy_match -/* Insert new strings in the hash table only if the match length - * is not greater than this length. This saves time but degrades compression. - * max_insert_length is used only for compression levels <= 3. - */ - -static const unsigned good_match=32; - -/* Use a faster search when the previous match is longer than this */ - - -/* Values for max_lazy_match, good_match and max_chain_length, depending on - * the desired pack level (0..9). The values given below have been tuned to - * exclude worst case performance for pathological files. Better values may be - * found for specific files. - */ - -static const int nice_match=258; /* Stop searching when current match exceeds this */ - -/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 - * For deflate_fast() (levels <= 3) good is ignored and lazy has a different - * meaning. - */ - -#define EQUAL 0 -/* result of memcmp for equal strings */ - -/* =========================================================================== - * Prototypes for local functions. - */ -static void fill_window (void); - -static int longest_match (IPos cur_match); - -#ifdef DEBUG -static void check_match (IPos start, IPos match, int length); -#endif - -/* =========================================================================== - * Update a hash value with the given input byte - * IN assertion: all calls to to UPDATE_HASH are made with consecutive - * input characters, so that a running hash key can be computed from the - * previous key instead of complete recalculation each time. - */ -#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK) - -/* =========================================================================== - * Insert string s in the dictionary and set match_head to the previous head - * of the hash chain (the most recent string with same hash key). Return - * the previous length of the hash chain. - * IN assertion: all calls to to INSERT_STRING are made with consecutive - * input characters and the first MIN_MATCH bytes of s are valid - * (except for the last MIN_MATCH-1 bytes of the input file). - */ -#define INSERT_STRING(s, match_head) \ - (UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \ - prev[(s) & WMASK] = match_head = head[ins_h], \ - head[ins_h] = (s)) - -/* =========================================================================== - * Initialize the "longest match" routines for a new file - */ -static void lm_init(ush *flags) -{ - register unsigned j; - - /* Initialize the hash table. */ - memzero((char *) head, HASH_SIZE * sizeof(*head)); - /* prev will be initialized on the fly */ - - *flags |= SLOW; - /* ??? reduce max_chain_length for binary files */ - - strstart = 0; - block_start = 0L; - - lookahead = read_buf((char *) window, - sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE); - - if (lookahead == 0 || lookahead == (unsigned) EOF) { - eofile = 1, lookahead = 0; - return; - } - eofile = 0; - /* Make sure that we always have enough lookahead. This is important - * if input comes from a device such as a tty. - */ - while (lookahead < MIN_LOOKAHEAD && !eofile) - fill_window(); - - ins_h = 0; - for (j = 0; j < MIN_MATCH - 1; j++) - UPDATE_HASH(ins_h, window[j]); - /* If lookahead < MIN_MATCH, ins_h is garbage, but this is - * not important since only literal bytes will be emitted. - */ -} - -/* =========================================================================== - * Set match_start to the longest match starting at the given string and - * return its length. Matches shorter or equal to prev_length are discarded, - * in which case the result is equal to prev_length and match_start is - * garbage. - * IN assertions: cur_match is the head of the hash chain for the current - * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 - */ - -/* For MSDOS, OS/2 and 386 Unix, an optimized version is in match.asm or - * match.s. The code is functionally equivalent, so you can use the C version - * if desired. - */ -static int longest_match(IPos cur_match) -{ - unsigned chain_length = max_chain_length; /* max hash chain length */ - register uch *scan = window + strstart; /* current string */ - register uch *match; /* matched string */ - register int len; /* length of current match */ - int best_len = prev_length; /* best match length so far */ - IPos limit = - - strstart > (IPos) MAX_DIST ? strstart - (IPos) MAX_DIST : NIL; - /* Stop when cur_match becomes <= limit. To simplify the code, - * we prevent matches with the string of window index 0. - */ - -/* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. - * It is easy to get rid of this optimization if necessary. - */ -#if HASH_BITS < 8 || MAX_MATCH != 258 -# error Code too clever -#endif - register uch *strend = window + strstart + MAX_MATCH; - register uch scan_end1 = scan[best_len - 1]; - register uch scan_end = scan[best_len]; - - /* Do not waste too much time if we already have a good match: */ - if (prev_length >= good_match) { - chain_length >>= 2; - } - Assert(strstart <= window_size - MIN_LOOKAHEAD, - "insufficient lookahead"); - - do { - Assert(cur_match < strstart, "no future"); - match = window + cur_match; - - /* Skip to next match if the match length cannot increase - * or if the match length is less than 2: - */ - if (match[best_len] != scan_end || - match[best_len - 1] != scan_end1 || - *match != *scan || *++match != scan[1]) - continue; - - /* The check at best_len-1 can be removed because it will be made - * again later. (This heuristic is not always a win.) - * It is not necessary to compare scan[2] and match[2] since they - * are always equal when the other bytes match, given that - * the hash keys are equal and that HASH_BITS >= 8. - */ - scan += 2, match++; - - /* We check for insufficient lookahead only every 8th comparison; - * the 256th check will be made at strstart+258. - */ - do { - } while (*++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - *++scan == *++match && *++scan == *++match && - scan < strend); - - len = MAX_MATCH - (int) (strend - scan); - scan = strend - MAX_MATCH; - - if (len > best_len) { - match_start = cur_match; - best_len = len; - if (len >= nice_match) - break; - scan_end1 = scan[best_len - 1]; - scan_end = scan[best_len]; - } - } while ((cur_match = prev[cur_match & WMASK]) > limit - && --chain_length != 0); - - return best_len; -} - -#ifdef DEBUG -/* =========================================================================== - * Check that the match at match_start is indeed a match. - */ -static void check_match(IPos start, IPos match, int length) -{ - /* check that the match is indeed a match */ - if (memcmp((char *) window + match, - (char *) window + start, length) != EQUAL) { - fprintf(stderr, - " start %d, match %d, length %d\n", start, match, length); - error_msg("invalid match"); - } - if (verbose > 1) { - fprintf(stderr, "\\[%d,%d]", start - match, length); - do { - putc(window[start++], stderr); - } while (--length != 0); - } -} -#else -# define check_match(start, match, length) -#endif - -/* =========================================================================== - * Fill the window when the lookahead becomes insufficient. - * Updates strstart and lookahead, and sets eofile if end of input file. - * IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0 - * OUT assertions: at least one byte has been read, or eofile is set; - * file reads are performed for at least two bytes (required for the - * translate_eol option). - */ -static void fill_window() -{ - register unsigned n, m; - unsigned more = - - (unsigned) (window_size - (ulg) lookahead - (ulg) strstart); - /* Amount of free space at the end of the window. */ - - /* If the window is almost full and there is insufficient lookahead, - * move the upper half to the lower one to make room in the upper half. - */ - if (more == (unsigned) EOF) { - /* Very unlikely, but possible on 16 bit machine if strstart == 0 - * and lookahead == 1 (input done one byte at time) - */ - more--; - } else if (strstart >= WSIZE + MAX_DIST) { - /* By the IN assertion, the window is not empty so we can't confuse - * more == 0 with more == 64K on a 16 bit machine. - */ - Assert(window_size == (ulg) 2 * WSIZE, "no sliding with BIG_MEM"); - - memcpy((char *) window, (char *) window + WSIZE, (unsigned) WSIZE); - match_start -= WSIZE; - strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */ - - block_start -= (long) WSIZE; - - for (n = 0; n < HASH_SIZE; n++) { - m = head[n]; - head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL); - } - for (n = 0; n < WSIZE; n++) { - m = prev[n]; - prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL); - /* If n is not on any hash chain, prev[n] is garbage but - * its value will never be used. - */ - } - more += WSIZE; - } - /* At this point, more >= 2 */ - if (!eofile) { - n = read_buf((char *) window + strstart + lookahead, more); - if (n == 0 || n == (unsigned) EOF) { - eofile = 1; - } else { - lookahead += n; - } - } -} - -/* =========================================================================== - * Flush the current block, with given end-of-file flag. - * IN assertion: strstart is set to the end of the current match. - */ -#define FLUSH_BLOCK(eof) \ - flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \ - (char*)NULL, (long)strstart - block_start, (eof)) - -/* =========================================================================== - * Same as above, but achieves better compression. We use a lazy - * evaluation for matches: a match is finally adopted only if there is - * no better match at the next window position. - */ -static ulg deflate() -{ - IPos hash_head; /* head of hash chain */ - IPos prev_match; /* previous match */ - int flush; /* set if current block must be flushed */ - int match_available = 0; /* set if previous match exists */ - register unsigned match_length = MIN_MATCH - 1; /* length of best match */ - - /* Process the input block. */ - while (lookahead != 0) { - /* Insert the string window[strstart .. strstart+2] in the - * dictionary, and set hash_head to the head of the hash chain: - */ - INSERT_STRING(strstart, hash_head); - - /* Find the longest match, discarding those <= prev_length. - */ - prev_length = match_length, prev_match = match_start; - match_length = MIN_MATCH - 1; - - if (hash_head != NIL && prev_length < max_lazy_match && - strstart - hash_head <= MAX_DIST) { - /* To simplify the code, we prevent matches with the string - * of window index 0 (in particular we have to avoid a match - * of the string with itself at the start of the input file). - */ - match_length = longest_match(hash_head); - /* longest_match() sets match_start */ - if (match_length > lookahead) - match_length = lookahead; - - /* Ignore a length 3 match if it is too distant: */ - if (match_length == MIN_MATCH - && strstart - match_start > TOO_FAR) { - /* If prev_match is also MIN_MATCH, match_start is garbage - * but we will ignore the current match anyway. - */ - match_length--; - } - } - /* If there was a match at the previous step and the current - * match is not better, output the previous match: - */ - if (prev_length >= MIN_MATCH && match_length <= prev_length) { - - check_match(strstart - 1, prev_match, prev_length); - - flush = - ct_tally(strstart - 1 - prev_match, - prev_length - MIN_MATCH); - - /* Insert in hash table all strings up to the end of the match. - * strstart-1 and strstart are already inserted. - */ - lookahead -= prev_length - 1; - prev_length -= 2; - do { - strstart++; - INSERT_STRING(strstart, hash_head); - /* strstart never exceeds WSIZE-MAX_MATCH, so there are - * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH - * these bytes are garbage, but it does not matter since the - * next lookahead bytes will always be emitted as literals. - */ - } while (--prev_length != 0); - match_available = 0; - match_length = MIN_MATCH - 1; - strstart++; - if (flush) - FLUSH_BLOCK(0), block_start = strstart; - - } else if (match_available) { - /* If there was no match at the previous position, output a - * single literal. If there was a match but the current match - * is longer, truncate the previous match to a single literal. - */ - Tracevv((stderr, "%c", window[strstart - 1])); - if (ct_tally(0, window[strstart - 1])) { - FLUSH_BLOCK(0), block_start = strstart; - } - strstart++; - lookahead--; - } else { - /* There is no previous match to compare with, wait for - * the next step to decide. - */ - match_available = 1; - strstart++; - lookahead--; - } - Assert(strstart <= isize && lookahead <= isize, "a bit too far"); - - /* Make sure that we always have enough lookahead, except - * at the end of the input file. We need MAX_MATCH bytes - * for the next match, plus MIN_MATCH bytes to insert the - * string following the next match. - */ - while (lookahead < MIN_LOOKAHEAD && !eofile) - fill_window(); - } - if (match_available) - ct_tally(0, window[strstart - 1]); - - return FLUSH_BLOCK(1); /* eof */ -} - -/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface - * Copyright (C) 1992-1993 Jean-loup Gailly - * The unzip code was written and put in the public domain by Mark Adler. - * Portions of the lzw code are derived from the public domain 'compress' - * written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies, - * Ken Turkowski, Dave Mack and Peter Jannesen. - * - * See the license_msg below and the file COPYING for the software license. - * See the file algorithm.doc for the compression algorithms and file formats. - */ - -/* Compress files with zip algorithm and 'compress' interface. - * See usage() and help() functions below for all options. - * Outputs: - * file.gz: compressed file with same mode, owner, and utimes - * or stdout with -c option or if stdin used as input. - * If the output file name had to be truncated, the original name is kept - * in the compressed file. - */ - - /* configuration */ - -typedef struct dirent dir_type; - -typedef RETSIGTYPE(*sig_type) (int); - - -/* ======================================================================== */ -// int main (argc, argv) -// int argc; -// char **argv; -int gzip_main(int argc, char **argv) -{ - int result; - int inFileNum; - int outFileNum; - struct stat statBuf; - char *delFileName; - int tostdout = 0; - int fromstdin = 0; - int force = 0; - int opt; - - while ((opt = getopt(argc, argv, "cf123456789dq")) != -1) { - switch (opt) { - case 'c': - tostdout = 1; - break; - case 'f': - force = 1; - break; - /* Ignore 1-9 (compression level) options */ - case '1': case '2': case '3': case '4': case '5': - case '6': case '7': case '8': case '9': - break; - case 'q': - break; -#ifdef BB_GUNZIP - case 'd': - optind = 1; - return gunzip_main(argc, argv); -#endif - default: - show_usage(); - } - } - if ((optind == argc) || (strcmp(argv[optind], "-") == 0)) { - fromstdin = 1; - tostdout = 1; - } - - if (isatty(fileno(stdout)) && tostdout==1 && force==0) - error_msg_and_die( "compressed data not written to terminal. Use -f to force it."); - - foreground = signal(SIGINT, SIG_IGN) != SIG_IGN; - if (foreground) { - (void) signal(SIGINT, (sig_type) abort_gzip); - } -#ifdef SIGTERM - if (signal(SIGTERM, SIG_IGN) != SIG_IGN) { - (void) signal(SIGTERM, (sig_type) abort_gzip); - } -#endif -#ifdef SIGHUP - if (signal(SIGHUP, SIG_IGN) != SIG_IGN) { - (void) signal(SIGHUP, (sig_type) abort_gzip); - } -#endif - - strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1); - z_len = strlen(z_suffix); - - /* Allocate all global buffers (for DYN_ALLOC option) */ - ALLOC(uch, inbuf, INBUFSIZ + INBUF_EXTRA); - ALLOC(uch, outbuf, OUTBUFSIZ + OUTBUF_EXTRA); - ALLOC(ush, d_buf, DIST_BUFSIZE); - ALLOC(uch, window, 2L * WSIZE); - ALLOC(ush, tab_prefix, 1L << BITS); - - if (fromstdin == 1) { - strcpy(ofname, "stdin"); - - inFileNum = fileno(stdin); - time_stamp = 0; /* time unknown by default */ - ifile_size = -1L; /* convention for unknown size */ - } else { - /* Open up the input file */ - strncpy(ifname, argv[optind], MAX_PATH_LEN); - - /* Open input file */ - inFileNum = open(ifname, O_RDONLY); - if (inFileNum < 0) - perror_msg_and_die("%s", ifname); - /* Get the time stamp on the input file. */ - if (stat(ifname, &statBuf) < 0) - perror_msg_and_die("%s", ifname); - time_stamp = statBuf.st_ctime; - ifile_size = statBuf.st_size; - } - - - if (tostdout == 1) { - /* And get to work */ - strcpy(ofname, "stdout"); - outFileNum = fileno(stdout); - - clear_bufs(); /* clear input and output buffers */ - part_nb = 0; - - /* Actually do the compression/decompression. */ - zip(inFileNum, outFileNum); - - } else { - - /* And get to work */ - strncpy(ofname, ifname, MAX_PATH_LEN - 4); - strcat(ofname, ".gz"); - - - /* Open output fille */ -#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) - outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW); -#else - outFileNum = open(ofname, O_RDWR | O_CREAT | O_EXCL); -#endif - if (outFileNum < 0) - perror_msg_and_die("%s", ofname); - /* Set permissions on the file */ - fchmod(outFileNum, statBuf.st_mode); - - clear_bufs(); /* clear input and output buffers */ - part_nb = 0; - - /* Actually do the compression/decompression. */ - result = zip(inFileNum, outFileNum); - close(outFileNum); - close(inFileNum); - /* Delete the original file */ - if (result == OK) - delFileName = ifname; - else - delFileName = ofname; - - if (unlink(delFileName) < 0) - perror_msg_and_die("%s", delFileName); - } - - return(exit_code); -} - -/* trees.c -- output deflated data using Huffman coding - * Copyright (C) 1992-1993 Jean-loup Gailly - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - -/* - * PURPOSE - * - * Encode various sets of source values using variable-length - * binary code trees. - * - * DISCUSSION - * - * The PKZIP "deflation" process uses several Huffman trees. The more - * common source values are represented by shorter bit sequences. - * - * Each code tree is stored in the ZIP file in a compressed form - * which is itself a Huffman encoding of the lengths of - * all the code strings (in ascending order by source values). - * The actual code strings are reconstructed from the lengths in - * the UNZIP process, as described in the "application note" - * (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program. - * - * REFERENCES - * - * Lynch, Thomas J. - * Data Compression: Techniques and Applications, pp. 53-55. - * Lifetime Learning Publications, 1985. ISBN 0-534-03418-7. - * - * Storer, James A. - * Data Compression: Methods and Theory, pp. 49-50. - * Computer Science Press, 1988. ISBN 0-7167-8156-5. - * - * Sedgewick, R. - * Algorithms, p290. - * Addison-Wesley, 1983. ISBN 0-201-06672-6. - * - * INTERFACE - * - * void ct_init (ush *attr, int *methodp) - * Allocate the match buffer, initialize the various tables and save - * the location of the internal file attribute (ascii/binary) and - * method (DEFLATE/STORE) - * - * void ct_tally (int dist, int lc); - * Save the match info and tally the frequency counts. - * - * long flush_block (char *buf, ulg stored_len, int eof) - * Determine the best encoding for the current block: dynamic trees, - * static trees or store, and output the encoded block to the zip - * file. Returns the total compressed length for the file so far. - * - */ - -/* =========================================================================== - * Constants - */ - -#define MAX_BITS 15 -/* All codes must not exceed MAX_BITS bits */ - -#define MAX_BL_BITS 7 -/* Bit length codes must not exceed MAX_BL_BITS bits */ - -#define LENGTH_CODES 29 -/* number of length codes, not counting the special END_BLOCK code */ - -#define LITERALS 256 -/* number of literal bytes 0..255 */ - -#define END_BLOCK 256 -/* end of block literal code */ - -#define L_CODES (LITERALS+1+LENGTH_CODES) -/* number of Literal or Length codes, including the END_BLOCK code */ - -#define D_CODES 30 -/* number of distance codes */ - -#define BL_CODES 19 -/* number of codes used to transfer the bit lengths */ - - -static const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ - = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, - 4, 4, 5, 5, 5, 5, 0 }; - -static const int extra_dbits[D_CODES] /* extra bits for each distance code */ - = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, - 10, 10, 11, 11, 12, 12, 13, 13 }; - -static const int extra_blbits[BL_CODES] /* extra bits for each bit length code */ -= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 }; - -#define STORED_BLOCK 0 -#define STATIC_TREES 1 -#define DYN_TREES 2 -/* The three kinds of block type */ - -#ifndef LIT_BUFSIZE -# ifdef SMALL_MEM -# define LIT_BUFSIZE 0x2000 -# else -# ifdef MEDIUM_MEM -# define LIT_BUFSIZE 0x4000 -# else -# define LIT_BUFSIZE 0x8000 -# endif -# endif -#endif -#ifndef DIST_BUFSIZE -# define DIST_BUFSIZE LIT_BUFSIZE -#endif -/* Sizes of match buffers for literals/lengths and distances. There are - * 4 reasons for limiting LIT_BUFSIZE to 64K: - * - frequencies can be kept in 16 bit counters - * - if compression is not successful for the first block, all input data is - * still in the window so we can still emit a stored block even when input - * comes from standard input. (This can also be done for all blocks if - * LIT_BUFSIZE is not greater than 32K.) - * - if compression is not successful for a file smaller than 64K, we can - * even emit a stored file instead of a stored block (saving 5 bytes). - * - creating new Huffman trees less frequently may not provide fast - * adaptation to changes in the input data statistics. (Take for - * example a binary file with poorly compressible code followed by - * a highly compressible string table.) Smaller buffer sizes give - * fast adaptation but have of course the overhead of transmitting trees - * more frequently. - * - I can't count above 4 - * The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save - * memory at the expense of compression). Some optimizations would be possible - * if we rely on DIST_BUFSIZE == LIT_BUFSIZE. - */ -#if LIT_BUFSIZE > INBUFSIZ -error cannot overlay l_buf and inbuf -#endif -#define REP_3_6 16 -/* repeat previous bit length 3-6 times (2 bits of repeat count) */ -#define REPZ_3_10 17 -/* repeat a zero length 3-10 times (3 bits of repeat count) */ -#define REPZ_11_138 18 -/* repeat a zero length 11-138 times (7 bits of repeat count) *//* =========================================================================== - * Local data - *//* Data structure describing a single value and its code string. */ typedef struct ct_data { - union { - ush freq; /* frequency count */ - ush code; /* bit string */ - } fc; - union { - ush dad; /* father node in Huffman tree */ - ush len; /* length of bit string */ - } dl; -} ct_data; - -#define Freq fc.freq -#define Code fc.code -#define Dad dl.dad -#define Len dl.len - -#define HEAP_SIZE (2*L_CODES+1) -/* maximum heap size */ - -static ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */ -static ct_data dyn_dtree[2 * D_CODES + 1]; /* distance tree */ - -static ct_data static_ltree[L_CODES + 2]; - -/* The static literal tree. Since the bit lengths are imposed, there is no - * need for the L_CODES extra codes used during heap construction. However - * The codes 286 and 287 are needed to build a canonical tree (see ct_init - * below). - */ - -static ct_data static_dtree[D_CODES]; - -/* The static distance tree. (Actually a trivial tree since all codes use - * 5 bits.) - */ - -static ct_data bl_tree[2 * BL_CODES + 1]; - -/* Huffman tree for the bit lengths */ - -typedef struct tree_desc { - ct_data *dyn_tree; /* the dynamic tree */ - ct_data *static_tree; /* corresponding static tree or NULL */ - const int *extra_bits; /* extra bits for each code or NULL */ - int extra_base; /* base index for extra_bits */ - int elems; /* max number of elements in the tree */ - int max_length; /* max bit length for the codes */ - int max_code; /* largest code with non zero frequency */ -} tree_desc; - -static tree_desc l_desc = - { dyn_ltree, static_ltree, extra_lbits, LITERALS + 1, L_CODES, - MAX_BITS, 0 }; - -static tree_desc d_desc = - { dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0 }; - -static tree_desc bl_desc = - { bl_tree, (ct_data *) 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, - 0 }; - - -static ush bl_count[MAX_BITS + 1]; - -/* number of codes at each bit length for an optimal tree */ - -static const uch bl_order[BL_CODES] -= { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 }; - -/* The lengths of the bit length codes are sent in order of decreasing - * probability, to avoid transmitting the lengths for unused bit length codes. - */ - -static int heap[2 * L_CODES + 1]; /* heap used to build the Huffman trees */ -static int heap_len; /* number of elements in the heap */ -static int heap_max; /* element of largest frequency */ - -/* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. - * The same heap array is used to build all trees. - */ - -static uch depth[2 * L_CODES + 1]; - -/* Depth of each subtree used as tie breaker for trees of equal frequency */ - -static uch length_code[MAX_MATCH - MIN_MATCH + 1]; - -/* length code for each normalized match length (0 == MIN_MATCH) */ - -static uch dist_code[512]; - -/* distance codes. The first 256 values correspond to the distances - * 3 .. 258, the last 256 values correspond to the top 8 bits of - * the 15 bit distances. - */ - -static int base_length[LENGTH_CODES]; - -/* First normalized length for each code (0 = MIN_MATCH) */ - -static int base_dist[D_CODES]; - -/* First normalized distance for each code (0 = distance of 1) */ - -#define l_buf inbuf -/* DECLARE(uch, l_buf, LIT_BUFSIZE); buffer for literals or lengths */ - -/* DECLARE(ush, d_buf, DIST_BUFSIZE); buffer for distances */ - -static uch flag_buf[(LIT_BUFSIZE / 8)]; - -/* flag_buf is a bit array distinguishing literals from lengths in - * l_buf, thus indicating the presence or absence of a distance. - */ - -static unsigned last_lit; /* running index in l_buf */ -static unsigned last_dist; /* running index in d_buf */ -static unsigned last_flags; /* running index in flag_buf */ -static uch flags; /* current flags not yet saved in flag_buf */ -static uch flag_bit; /* current bit used in flags */ - -/* bits are filled in flags starting at bit 0 (least significant). - * Note: these flags are overkill in the current code since we don't - * take advantage of DIST_BUFSIZE == LIT_BUFSIZE. - */ - -static ulg opt_len; /* bit length of current block with optimal trees */ -static ulg static_len; /* bit length of current block with static trees */ - -static ulg compressed_len; /* total bit length of compressed file */ - - -static ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */ -static int *file_method; /* pointer to DEFLATE or STORE */ - -/* =========================================================================== - * Local (static) routines in this file. - */ - -static void init_block (void); -static void pqdownheap (ct_data * tree, int k); -static void gen_bitlen (tree_desc * desc); -static void gen_codes (ct_data * tree, int max_code); -static void build_tree (tree_desc * desc); -static void scan_tree (ct_data * tree, int max_code); -static void send_tree (ct_data * tree, int max_code); -static int build_bl_tree (void); -static void send_all_trees (int lcodes, int dcodes, int blcodes); -static void compress_block (ct_data * ltree, ct_data * dtree); -static void set_file_type (void); - - -#ifndef DEBUG -# define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len) - /* Send a code of the given tree. c and tree must not have side effects */ - -#else /* DEBUG */ -# define send_code(c, tree) \ - { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ - send_bits(tree[c].Code, tree[c].Len); } -#endif - -#define d_code(dist) \ - ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) -/* Mapping from a distance to a distance code. dist is the distance - 1 and - * must not have side effects. dist_code[256] and dist_code[257] are never - * used. - */ - -/* the arguments must not have side effects */ - -/* =========================================================================== - * Allocate the match buffer, initialize the various tables and save the - * location of the internal file attribute (ascii/binary) and method - * (DEFLATE/STORE). - */ -static void ct_init(ush *attr, int *methodp) -{ - int n; /* iterates over tree elements */ - int bits; /* bit counter */ - int length; /* length value */ - int code; /* code value */ - int dist; /* distance index */ - - file_type = attr; - file_method = methodp; - compressed_len = 0L; - - if (static_dtree[0].Len != 0) - return; /* ct_init already called */ - - /* Initialize the mapping length (0..255) -> length code (0..28) */ - length = 0; - for (code = 0; code < LENGTH_CODES - 1; code++) { - base_length[code] = length; - for (n = 0; n < (1 << extra_lbits[code]); n++) { - length_code[length++] = (uch) code; - } - } - Assert(length == 256, "ct_init: length != 256"); - /* Note that the length 255 (match length 258) can be represented - * in two different ways: code 284 + 5 bits or code 285, so we - * overwrite length_code[255] to use the best encoding: - */ - length_code[length - 1] = (uch) code; - - /* Initialize the mapping dist (0..32K) -> dist code (0..29) */ - dist = 0; - for (code = 0; code < 16; code++) { - base_dist[code] = dist; - for (n = 0; n < (1 << extra_dbits[code]); n++) { - dist_code[dist++] = (uch) code; - } - } - Assert(dist == 256, "ct_init: dist != 256"); - dist >>= 7; /* from now on, all distances are divided by 128 */ - for (; code < D_CODES; code++) { - base_dist[code] = dist << 7; - for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) { - dist_code[256 + dist++] = (uch) code; - } - } - Assert(dist == 256, "ct_init: 256+dist != 512"); - - /* Construct the codes of the static literal tree */ - for (bits = 0; bits <= MAX_BITS; bits++) - bl_count[bits] = 0; - n = 0; - while (n <= 143) - static_ltree[n++].Len = 8, bl_count[8]++; - while (n <= 255) - static_ltree[n++].Len = 9, bl_count[9]++; - while (n <= 279) - static_ltree[n++].Len = 7, bl_count[7]++; - while (n <= 287) - static_ltree[n++].Len = 8, bl_count[8]++; - /* Codes 286 and 287 do not exist, but we must include them in the - * tree construction to get a canonical Huffman tree (longest code - * all ones) - */ - gen_codes((ct_data *) static_ltree, L_CODES + 1); - - /* The static distance tree is trivial: */ - for (n = 0; n < D_CODES; n++) { - static_dtree[n].Len = 5; - static_dtree[n].Code = bi_reverse(n, 5); - } - - /* Initialize the first block of the first file: */ - init_block(); -} - -/* =========================================================================== - * Initialize a new block. - */ -static void init_block() -{ - int n; /* iterates over tree elements */ - - /* Initialize the trees. */ - for (n = 0; n < L_CODES; n++) - dyn_ltree[n].Freq = 0; - for (n = 0; n < D_CODES; n++) - dyn_dtree[n].Freq = 0; - for (n = 0; n < BL_CODES; n++) - bl_tree[n].Freq = 0; - - dyn_ltree[END_BLOCK].Freq = 1; - opt_len = static_len = 0L; - last_lit = last_dist = last_flags = 0; - flags = 0; - flag_bit = 1; -} - -#define SMALLEST 1 -/* Index within the heap array of least frequent node in the Huffman tree */ - - -/* =========================================================================== - * Remove the smallest element from the heap and recreate the heap with - * one less element. Updates heap and heap_len. - */ -#define pqremove(tree, top) \ -{\ - top = heap[SMALLEST]; \ - heap[SMALLEST] = heap[heap_len--]; \ - pqdownheap(tree, SMALLEST); \ -} - -/* =========================================================================== - * Compares to subtrees, using the tree depth as tie breaker when - * the subtrees have equal frequency. This minimizes the worst case length. - */ -#define smaller(tree, n, m) \ - (tree[n].Freq < tree[m].Freq || \ - (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) - -/* =========================================================================== - * Restore the heap property by moving down the tree starting at node k, - * exchanging a node with the smallest of its two sons if necessary, stopping - * when the heap property is re-established (each father smaller than its - * two sons). - */ -static void pqdownheap(ct_data *tree, int k) -{ - int v = heap[k]; - int j = k << 1; /* left son of k */ - - while (j <= heap_len) { - /* Set j to the smallest of the two sons: */ - if (j < heap_len && smaller(tree, heap[j + 1], heap[j])) - j++; - - /* Exit if v is smaller than both sons */ - if (smaller(tree, v, heap[j])) - break; - - /* Exchange v with the smallest son */ - heap[k] = heap[j]; - k = j; - - /* And continue down the tree, setting j to the left son of k */ - j <<= 1; - } - heap[k] = v; -} - -/* =========================================================================== - * Compute the optimal bit lengths for a tree and update the total bit length - * for the current block. - * IN assertion: the fields freq and dad are set, heap[heap_max] and - * above are the tree nodes sorted by increasing frequency. - * OUT assertions: the field len is set to the optimal bit length, the - * array bl_count contains the frequencies for each bit length. - * The length opt_len is updated; static_len is also updated if stree is - * not null. - */ -static void gen_bitlen(tree_desc *desc) -{ - ct_data *tree = desc->dyn_tree; - const int *extra = desc->extra_bits; - int base = desc->extra_base; - int max_code = desc->max_code; - int max_length = desc->max_length; - ct_data *stree = desc->static_tree; - int h; /* heap index */ - int n, m; /* iterate over the tree elements */ - int bits; /* bit length */ - int xbits; /* extra bits */ - ush f; /* frequency */ - int overflow = 0; /* number of elements with bit length too large */ - - for (bits = 0; bits <= MAX_BITS; bits++) - bl_count[bits] = 0; - - /* In a first pass, compute the optimal bit lengths (which may - * overflow in the case of the bit length tree). - */ - tree[heap[heap_max]].Len = 0; /* root of the heap */ - - for (h = heap_max + 1; h < HEAP_SIZE; h++) { - n = heap[h]; - bits = tree[tree[n].Dad].Len + 1; - if (bits > max_length) - bits = max_length, overflow++; - tree[n].Len = (ush) bits; - /* We overwrite tree[n].Dad which is no longer needed */ - - if (n > max_code) - continue; /* not a leaf node */ - - bl_count[bits]++; - xbits = 0; - if (n >= base) - xbits = extra[n - base]; - f = tree[n].Freq; - opt_len += (ulg) f *(bits + xbits); - - if (stree) - static_len += (ulg) f *(stree[n].Len + xbits); - } - if (overflow == 0) - return; - - Trace((stderr, "\nbit length overflow\n")); - /* This happens for example on obj2 and pic of the Calgary corpus */ - - /* Find the first bit length which could increase: */ - do { - bits = max_length - 1; - while (bl_count[bits] == 0) - bits--; - bl_count[bits]--; /* move one leaf down the tree */ - bl_count[bits + 1] += 2; /* move one overflow item as its brother */ - bl_count[max_length]--; - /* The brother of the overflow item also moves one step up, - * but this does not affect bl_count[max_length] - */ - overflow -= 2; - } while (overflow > 0); - - /* Now recompute all bit lengths, scanning in increasing frequency. - * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all - * lengths instead of fixing only the wrong ones. This idea is taken - * from 'ar' written by Haruhiko Okumura.) - */ - for (bits = max_length; bits != 0; bits--) { - n = bl_count[bits]; - while (n != 0) { - m = heap[--h]; - if (m > max_code) - continue; - if (tree[m].Len != (unsigned) bits) { - Trace( - (stderr, "code %d bits %d->%d\n", m, tree[m].Len, - bits)); - opt_len += - ((long) bits - - (long) tree[m].Len) * (long) tree[m].Freq; - tree[m].Len = (ush) bits; - } - n--; - } - } -} - -/* =========================================================================== - * Generate the codes for a given tree and bit counts (which need not be - * optimal). - * IN assertion: the array bl_count contains the bit length statistics for - * the given tree and the field len is set for all tree elements. - * OUT assertion: the field code is set for all tree elements of non - * zero code length. - */ -static void gen_codes(ct_data *tree, int max_code) -{ - ush next_code[MAX_BITS + 1]; /* next code value for each bit length */ - ush code = 0; /* running code value */ - int bits; /* bit index */ - int n; /* code index */ - - /* The distribution counts are first used to generate the code values - * without bit reversal. - */ - for (bits = 1; bits <= MAX_BITS; bits++) { - next_code[bits] = code = (code + bl_count[bits - 1]) << 1; - } - /* Check that the bit counts in bl_count are consistent. The last code - * must be all ones. - */ - Assert(code + bl_count[MAX_BITS] - 1 == (1 << MAX_BITS) - 1, - "inconsistent bit counts"); - Tracev((stderr, "\ngen_codes: max_code %d ", max_code)); - - for (n = 0; n <= max_code; n++) { - int len = tree[n].Len; - - if (len == 0) - continue; - /* Now reverse the bits */ - tree[n].Code = bi_reverse(next_code[len]++, len); - - Tracec(tree != static_ltree, - (stderr, "\nn %3d %c l %2d c %4x (%x) ", n, - (isgraph(n) ? n : ' '), len, tree[n].Code, - next_code[len] - 1)); - } -} - -/* =========================================================================== - * Construct one Huffman tree and assigns the code bit strings and lengths. - * Update the total bit length for the current block. - * IN assertion: the field freq is set for all tree elements. - * OUT assertions: the fields len and code are set to the optimal bit length - * and corresponding code. The length opt_len is updated; static_len is - * also updated if stree is not null. The field max_code is set. - */ -static void build_tree(tree_desc *desc) -{ - ct_data *tree = desc->dyn_tree; - ct_data *stree = desc->static_tree; - int elems = desc->elems; - int n, m; /* iterate over heap elements */ - int max_code = -1; /* largest code with non zero frequency */ - int node = elems; /* next internal node of the tree */ - - /* Construct the initial heap, with least frequent element in - * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. - * heap[0] is not used. - */ - heap_len = 0, heap_max = HEAP_SIZE; - - for (n = 0; n < elems; n++) { - if (tree[n].Freq != 0) { - heap[++heap_len] = max_code = n; - depth[n] = 0; - } else { - tree[n].Len = 0; - } - } - - /* The pkzip format requires that at least one distance code exists, - * and that at least one bit should be sent even if there is only one - * possible code. So to avoid special checks later on we force at least - * two codes of non zero frequency. - */ - while (heap_len < 2) { - int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0); - - tree[new].Freq = 1; - depth[new] = 0; - opt_len--; - if (stree) - static_len -= stree[new].Len; - /* new is 0 or 1 so it does not have extra bits */ - } - desc->max_code = max_code; - - /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, - * establish sub-heaps of increasing lengths: - */ - for (n = heap_len / 2; n >= 1; n--) - pqdownheap(tree, n); - - /* Construct the Huffman tree by repeatedly combining the least two - * frequent nodes. - */ - do { - pqremove(tree, n); /* n = node of least frequency */ - m = heap[SMALLEST]; /* m = node of next least frequency */ - - heap[--heap_max] = n; /* keep the nodes sorted by frequency */ - heap[--heap_max] = m; - - /* Create a new node father of n and m */ - tree[node].Freq = tree[n].Freq + tree[m].Freq; - depth[node] = (uch) (MAX(depth[n], depth[m]) + 1); - tree[n].Dad = tree[m].Dad = (ush) node; -#ifdef DUMP_BL_TREE - if (tree == bl_tree) { - fprintf(stderr, "\nnode %d(%d), sons %d(%d) %d(%d)", - node, tree[node].Freq, n, tree[n].Freq, m, - tree[m].Freq); - } -#endif - /* and insert the new node in the heap */ - heap[SMALLEST] = node++; - pqdownheap(tree, SMALLEST); - - } while (heap_len >= 2); - - heap[--heap_max] = heap[SMALLEST]; - - /* At this point, the fields freq and dad are set. We can now - * generate the bit lengths. - */ - gen_bitlen((tree_desc *) desc); - - /* The field len is now set, we can generate the bit codes */ - gen_codes((ct_data *) tree, max_code); -} - -/* =========================================================================== - * Scan a literal or distance tree to determine the frequencies of the codes - * in the bit length tree. Updates opt_len to take into account the repeat - * counts. (The contribution of the bit length codes will be added later - * during the construction of bl_tree.) - */ -static void scan_tree(ct_data *tree, int max_code) -{ - int n; /* iterates over all tree elements */ - int prevlen = -1; /* last emitted length */ - int curlen; /* length of current code */ - int nextlen = tree[0].Len; /* length of next code */ - int count = 0; /* repeat count of the current code */ - int max_count = 7; /* max repeat count */ - int min_count = 4; /* min repeat count */ - - if (nextlen == 0) - max_count = 138, min_count = 3; - tree[max_code + 1].Len = (ush) 0xffff; /* guard */ - - for (n = 0; n <= max_code; n++) { - curlen = nextlen; - nextlen = tree[n + 1].Len; - if (++count < max_count && curlen == nextlen) { - continue; - } else if (count < min_count) { - bl_tree[curlen].Freq += count; - } else if (curlen != 0) { - if (curlen != prevlen) - bl_tree[curlen].Freq++; - bl_tree[REP_3_6].Freq++; - } else if (count <= 10) { - bl_tree[REPZ_3_10].Freq++; - } else { - bl_tree[REPZ_11_138].Freq++; - } - count = 0; - prevlen = curlen; - if (nextlen == 0) { - max_count = 138, min_count = 3; - } else if (curlen == nextlen) { - max_count = 6, min_count = 3; - } else { - max_count = 7, min_count = 4; - } - } -} - -/* =========================================================================== - * Send a literal or distance tree in compressed form, using the codes in - * bl_tree. - */ -static void send_tree(ct_data *tree, int max_code) -{ - int n; /* iterates over all tree elements */ - int prevlen = -1; /* last emitted length */ - int curlen; /* length of current code */ - int nextlen = tree[0].Len; /* length of next code */ - int count = 0; /* repeat count of the current code */ - int max_count = 7; /* max repeat count */ - int min_count = 4; /* min repeat count */ - -/* tree[max_code+1].Len = -1; *//* guard already set */ - if (nextlen == 0) - max_count = 138, min_count = 3; - - for (n = 0; n <= max_code; n++) { - curlen = nextlen; - nextlen = tree[n + 1].Len; - if (++count < max_count && curlen == nextlen) { - continue; - } else if (count < min_count) { - do { - send_code(curlen, bl_tree); - } while (--count != 0); - - } else if (curlen != 0) { - if (curlen != prevlen) { - send_code(curlen, bl_tree); - count--; - } - Assert(count >= 3 && count <= 6, " 3_6?"); - send_code(REP_3_6, bl_tree); - send_bits(count - 3, 2); - - } else if (count <= 10) { - send_code(REPZ_3_10, bl_tree); - send_bits(count - 3, 3); - - } else { - send_code(REPZ_11_138, bl_tree); - send_bits(count - 11, 7); - } - count = 0; - prevlen = curlen; - if (nextlen == 0) { - max_count = 138, min_count = 3; - } else if (curlen == nextlen) { - max_count = 6, min_count = 3; - } else { - max_count = 7, min_count = 4; - } - } -} - -/* =========================================================================== - * Construct the Huffman tree for the bit lengths and return the index in - * bl_order of the last bit length code to send. - */ -static const int build_bl_tree() -{ - int max_blindex; /* index of last bit length code of non zero freq */ - - /* Determine the bit length frequencies for literal and distance trees */ - scan_tree((ct_data *) dyn_ltree, l_desc.max_code); - scan_tree((ct_data *) dyn_dtree, d_desc.max_code); - - /* Build the bit length tree: */ - build_tree((tree_desc *) (&bl_desc)); - /* opt_len now includes the length of the tree representations, except - * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. - */ - - /* Determine the number of bit length codes to send. The pkzip format - * requires that at least 4 bit length codes be sent. (appnote.txt says - * 3 but the actual value used is 4.) - */ - for (max_blindex = BL_CODES - 1; max_blindex >= 3; max_blindex--) { - if (bl_tree[bl_order[max_blindex]].Len != 0) - break; - } - /* Update opt_len to include the bit length tree and counts */ - opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4; - Tracev( - (stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, - static_len)); - - return max_blindex; -} - -/* =========================================================================== - * Send the header for a block using dynamic Huffman trees: the counts, the - * lengths of the bit length codes, the literal tree and the distance tree. - * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. - */ -static void send_all_trees(int lcodes, int dcodes, int blcodes) -{ - int rank; /* index in bl_order */ - - Assert(lcodes >= 257 && dcodes >= 1 - && blcodes >= 4, "not enough codes"); - Assert(lcodes <= L_CODES && dcodes <= D_CODES - && blcodes <= BL_CODES, "too many codes"); - Tracev((stderr, "\nbl counts: ")); - send_bits(lcodes - 257, 5); /* not +255 as stated in appnote.txt */ - send_bits(dcodes - 1, 5); - send_bits(blcodes - 4, 4); /* not -3 as stated in appnote.txt */ - for (rank = 0; rank < blcodes; rank++) { - Tracev((stderr, "\nbl code %2d ", bl_order[rank])); - send_bits(bl_tree[bl_order[rank]].Len, 3); - } - Tracev((stderr, "\nbl tree: sent %ld", bits_sent)); - - send_tree((ct_data *) dyn_ltree, lcodes - 1); /* send the literal tree */ - Tracev((stderr, "\nlit tree: sent %ld", bits_sent)); - - send_tree((ct_data *) dyn_dtree, dcodes - 1); /* send the distance tree */ - Tracev((stderr, "\ndist tree: sent %ld", bits_sent)); -} - -/* =========================================================================== - * Determine the best encoding for the current block: dynamic trees, static - * trees or store, and output the encoded block to the zip file. This function - * returns the total compressed length for the file so far. - */ -static ulg flush_block(char *buf, ulg stored_len, int eof) -{ - ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ - int max_blindex; /* index of last bit length code of non zero freq */ - - flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */ - - /* Check if the file is ascii or binary */ - if (*file_type == (ush) UNKNOWN) - set_file_type(); - - /* Construct the literal and distance trees */ - build_tree((tree_desc *) (&l_desc)); - Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len)); - - build_tree((tree_desc *) (&d_desc)); - Tracev( - (stderr, "\ndist data: dyn %ld, stat %ld", opt_len, - static_len)); - /* At this point, opt_len and static_len are the total bit lengths of - * the compressed block data, excluding the tree representations. - */ - - /* Build the bit length tree for the above two trees, and get the index - * in bl_order of the last bit length code to send. - */ - max_blindex = build_bl_tree(); - - /* Determine the best encoding. Compute first the block length in bytes */ - opt_lenb = (opt_len + 3 + 7) >> 3; - static_lenb = (static_len + 3 + 7) >> 3; - - Trace( - (stderr, - "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ", - opt_lenb, opt_len, static_lenb, static_len, stored_len, - last_lit, last_dist)); - - if (static_lenb <= opt_lenb) - opt_lenb = static_lenb; - - /* If compression failed and this is the first and last block, - * and if the zip file can be seeked (to rewrite the local header), - * the whole file is transformed into a stored file: - */ - if (stored_len <= opt_lenb && eof && compressed_len == 0L - && seekable()) { - /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ - if (buf == (char *) 0) - error_msg("block vanished"); - - copy_block(buf, (unsigned) stored_len, 0); /* without header */ - compressed_len = stored_len << 3; - *file_method = STORED; - - } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) { - /* 4: two words for the lengths */ - /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. - * Otherwise we can't have processed more than WSIZE input bytes since - * the last block flush, because compression would have been - * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to - * transform a block into a stored block. - */ - send_bits((STORED_BLOCK << 1) + eof, 3); /* send block type */ - compressed_len = (compressed_len + 3 + 7) & ~7L; - compressed_len += (stored_len + 4) << 3; - - copy_block(buf, (unsigned) stored_len, 1); /* with header */ - - } else if (static_lenb == opt_lenb) { - send_bits((STATIC_TREES << 1) + eof, 3); - compress_block((ct_data *) static_ltree, - (ct_data *) static_dtree); - compressed_len += 3 + static_len; - } else { - send_bits((DYN_TREES << 1) + eof, 3); - send_all_trees(l_desc.max_code + 1, d_desc.max_code + 1, - max_blindex + 1); - compress_block((ct_data *) dyn_ltree, - (ct_data *) dyn_dtree); - compressed_len += 3 + opt_len; - } - Assert(compressed_len == bits_sent, "bad compressed size"); - init_block(); - - if (eof) { - bi_windup(); - compressed_len += 7; /* align on byte boundary */ - } - Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3, - compressed_len - 7 * eof)); - - return compressed_len >> 3; -} - -/* =========================================================================== - * Save the match info and tally the frequency counts. Return true if - * the current block must be flushed. - */ -static int ct_tally(int dist, int lc) -{ - l_buf[last_lit++] = (uch) lc; - if (dist == 0) { - /* lc is the unmatched char */ - dyn_ltree[lc].Freq++; - } else { - /* Here, lc is the match length - MIN_MATCH */ - dist--; /* dist = match distance - 1 */ - Assert((ush) dist < (ush) MAX_DIST && - (ush) lc <= (ush) (MAX_MATCH - MIN_MATCH) && - (ush) d_code(dist) < (ush) D_CODES, "ct_tally: bad match"); - - dyn_ltree[length_code[lc] + LITERALS + 1].Freq++; - dyn_dtree[d_code(dist)].Freq++; - - d_buf[last_dist++] = (ush) dist; - flags |= flag_bit; - } - flag_bit <<= 1; - - /* Output the flags if they fill a byte: */ - if ((last_lit & 7) == 0) { - flag_buf[last_flags++] = flags; - flags = 0, flag_bit = 1; - } - /* Try to guess if it is profitable to stop the current block here */ - if ((last_lit & 0xfff) == 0) { - /* Compute an upper bound for the compressed length */ - ulg out_length = (ulg) last_lit * 8L; - ulg in_length = (ulg) strstart - block_start; - int dcode; - - for (dcode = 0; dcode < D_CODES; dcode++) { - out_length += - (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]); - } - out_length >>= 3; - Trace( - (stderr, - "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ", - last_lit, last_dist, in_length, out_length, - 100L - out_length * 100L / in_length)); - if (last_dist < last_lit / 2 && out_length < in_length / 2) - return 1; - } - return (last_lit == LIT_BUFSIZE - 1 || last_dist == DIST_BUFSIZE); - /* We avoid equality with LIT_BUFSIZE because of wraparound at 64K - * on 16 bit machines and because stored blocks are restricted to - * 64K-1 bytes. - */ -} - -/* =========================================================================== - * Send the block data compressed using the given Huffman trees - */ -static void compress_block(ct_data *ltree, ct_data *dtree) -{ - unsigned dist; /* distance of matched string */ - int lc; /* match length or unmatched char (if dist == 0) */ - unsigned lx = 0; /* running index in l_buf */ - unsigned dx = 0; /* running index in d_buf */ - unsigned fx = 0; /* running index in flag_buf */ - uch flag = 0; /* current flags */ - unsigned code; /* the code to send */ - int extra; /* number of extra bits to send */ - - if (last_lit != 0) - do { - if ((lx & 7) == 0) - flag = flag_buf[fx++]; - lc = l_buf[lx++]; - if ((flag & 1) == 0) { - send_code(lc, ltree); /* send a literal byte */ - Tracecv(isgraph(lc), (stderr, " '%c' ", lc)); - } else { - /* Here, lc is the match length - MIN_MATCH */ - code = length_code[lc]; - send_code(code + LITERALS + 1, ltree); /* send the length code */ - extra = extra_lbits[code]; - if (extra != 0) { - lc -= base_length[code]; - send_bits(lc, extra); /* send the extra length bits */ - } - dist = d_buf[dx++]; - /* Here, dist is the match distance - 1 */ - code = d_code(dist); - Assert(code < D_CODES, "bad d_code"); - - send_code(code, dtree); /* send the distance code */ - extra = extra_dbits[code]; - if (extra != 0) { - dist -= base_dist[code]; - send_bits(dist, extra); /* send the extra distance bits */ - } - } /* literal or match pair ? */ - flag >>= 1; - } while (lx < last_lit); - - send_code(END_BLOCK, ltree); -} - -/* =========================================================================== - * Set the file type to ASCII or BINARY, using a crude approximation: - * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. - * IN assertion: the fields freq of dyn_ltree are set and the total of all - * frequencies does not exceed 64K (to fit in an int on 16 bit machines). - */ -static void set_file_type() -{ - int n = 0; - unsigned ascii_freq = 0; - unsigned bin_freq = 0; - - while (n < 7) - bin_freq += dyn_ltree[n++].Freq; - while (n < 128) - ascii_freq += dyn_ltree[n++].Freq; - while (n < LITERALS) - bin_freq += dyn_ltree[n++].Freq; - *file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII; - if (*file_type == BINARY && translate_eol) { - error_msg("-l used on binary file"); - } -} - -/* zip.c -- compress files to the gzip or pkzip format - * Copyright (C) 1992-1993 Jean-loup Gailly - * This is free software; you can redistribute it and/or modify it under the - * terms of the GNU General Public License, see the file COPYING. - */ - - -static ulg crc; /* crc on uncompressed file data */ -static long header_bytes; /* number of bytes in gzip header */ - -/* =========================================================================== - * Deflate in to out. - * IN assertions: the input and output buffers are cleared. - * The variables time_stamp and save_orig_name are initialized. - */ -static int zip(int in, int out) -{ - uch my_flags = 0; /* general purpose bit flags */ - ush attr = 0; /* ascii/binary flag */ - ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */ - - ifd = in; - ofd = out; - outcnt = 0; - - /* Write the header to the gzip file. See algorithm.doc for the format */ - - - method = DEFLATED; - put_byte(GZIP_MAGIC[0]); /* magic header */ - put_byte(GZIP_MAGIC[1]); - put_byte(DEFLATED); /* compression method */ - - put_byte(my_flags); /* general flags */ - put_long(time_stamp); - - /* Write deflated file to zip file */ - crc = updcrc(0, 0); - - bi_init(out); - ct_init(&attr, &method); - lm_init(&deflate_flags); - - put_byte((uch) deflate_flags); /* extra flags */ - put_byte(OS_CODE); /* OS identifier */ - - header_bytes = (long) outcnt; - - (void) deflate(); - - /* Write the crc and uncompressed size */ - put_long(crc); - put_long(isize); - header_bytes += 2 * sizeof(long); - - flush_outbuf(); - return OK; -} - - -/* =========================================================================== - * Read a new buffer from the current input file, perform end-of-line - * translation, and update the crc and input file size. - * IN assertion: size >= 2 (for end-of-line translation) - */ -static int file_read(char *buf, unsigned size) -{ - unsigned len; - - Assert(insize == 0, "inbuf not empty"); - - len = read(ifd, buf, size); - if (len == (unsigned) (-1) || len == 0) - return (int) len; - - crc = updcrc((uch *) buf, len); - isize += (ulg) len; - return (int) len; -} - -/* =========================================================================== - * Write the output buffer outbuf[0..outcnt-1] and update bytes_out. - * (used for the compressed data only) - */ -static void flush_outbuf() -{ - if (outcnt == 0) - return; - - write_buf(ofd, (char *) outbuf, outcnt); - outcnt = 0; -} |