* 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."
+ * "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@codepoet.org> to support
* files as well as stdin/stdout, and to generally behave itself wrt
* command line handling.
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+/* big objects in bss:
+ * 00000020 b bl_count
+ * 00000074 b base_length
+ * 00000078 b base_dist
+ * 00000078 b static_dtree
+ * 0000009c b bl_tree
+ * 000000f4 b dyn_dtree
+ * 00000100 b length_code
+ * 00000200 b dist_code
+ * 0000023d b depth
+ * 00000400 b flag_buf
+ * 0000047a b heap
+ * 00000480 b static_ltree
+ * 000008f4 b dyn_ltree
*/
-
/* TODO: full support for -v for DESKTOP
-/usr/bin/gzip -v a bogus aa
+ * "/usr/bin/gzip -v a bogus aa" should say:
a: 85.1% -- replaced with a.gz
gzip: bogus: No such file or directory
aa: 85.1% -- replaced with aa.gz
*/
-#define SMALL_MEM
-
-#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"
-
-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
-
-/* 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
+//config:config GZIP
+//config: bool "gzip"
+//config: default y
+//config: help
+//config: gzip is used to compress files.
+//config: It's probably the most widely used UNIX compression program.
+//config:
+//config:config FEATURE_GZIP_LONG_OPTIONS
+//config: bool "Enable long options"
+//config: default y
+//config: depends on GZIP && LONG_OPTS
+//config: help
+//config: Enable use of long options, increases size by about 106 Bytes
+//config:
+//config:config GZIP_FAST
+//config: int "Trade memory for gzip speed (0:small,slow - 2:fast,big)"
+//config: default 0
+//config: range 0 2
+//config: depends on GZIP
+//config: help
+//config: Enable big memory options for gzip.
+//config: 0: small buffers, small hash-tables
+//config: 1: larger buffers, larger hash-tables
+//config: 2: larger buffers, largest hash-tables
+//config: Larger models may give slightly better compression
+
+//applet:IF_GZIP(APPLET(gzip, BB_DIR_BIN, BB_SUID_DROP))
+//kbuild:lib-$(CONFIG_GZIP) += gzip.o
+
+//usage:#define gzip_trivial_usage
+//usage: "[-cfd] [FILE]..."
+//usage:#define gzip_full_usage "\n\n"
+//usage: "Compress FILEs (or stdin)\n"
+//usage: "\n -d Decompress"
+//usage: "\n -c Write to stdout"
+//usage: "\n -f Force"
+//usage:
+//usage:#define gzip_example_usage
+//usage: "$ ls -la /tmp/busybox*\n"
+//usage: "-rw-rw-r-- 1 andersen andersen 1761280 Apr 14 17:47 /tmp/busybox.tar\n"
+//usage: "$ gzip /tmp/busybox.tar\n"
+//usage: "$ ls -la /tmp/busybox*\n"
+//usage: "-rw-rw-r-- 1 andersen andersen 554058 Apr 14 17:49 /tmp/busybox.tar.gz\n"
+
+#include "libbb.h"
+#include "bb_archive.h"
+
+
+/* ===========================================================================
+ */
+//#define DEBUG 1
+/* Diagnostic functions */
+#ifdef DEBUG
+# define Assert(cond,msg) { if (!(cond)) bb_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
+
+
+/* ===========================================================================
+ */
+#if CONFIG_GZIP_FAST == 0
+# define SMALL_MEM
+#elif CONFIG_GZIP_FAST == 1
+# define MEDIUM_MEM
+#elif CONFIG_GZIP_FAST == 2
+# define BIG_MEM
+#else
+# error "Invalid CONFIG_GZIP_FAST value"
+#endif
+
+#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
+#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
# endif
#endif
-# define DECLARE(type, array, size) static type * array
-# define ALLOC(type, array, size) { \
- array = xzalloc((size_t)(((size)+1L)/2) * 2*sizeof(type)); \
- }
-# define FREE(array) {free(array), array=NULL;}
-
-#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 */
* 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();}
-
-#define seekable() 0 /* force sequential output */
-#define translate_eol 0 /* no option -a yet */
-
-/* Diagnostic functions */
-#ifdef DEBUG
-# define Assert(cond,msg) {if(!(cond)) bb_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 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.
- */
+#define seekable() 0 /* force sequential output */
+#define translate_eol 0 /* no option -a yet */
#ifndef BITS
# define BITS 16
* "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.
- */
+#ifdef MAX_EXT_CHARS
+# define MAX_SUFFIX MAX_EXT_CHARS
+#else
+# define MAX_SUFFIX 30
+#endif
- /* Common defaults */
+/* ===========================================================================
+ * 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.
+ */
-#ifndef OS_CODE
-# define OS_CODE 0x03 /* assume Unix */
+#ifdef SMALL_MEM
+# define HASH_BITS 13 /* Number of bits used to hash strings */
#endif
-
-#ifndef PATH_SEP
-# define PATH_SEP '/'
+#ifdef MEDIUM_MEM
+# define HASH_BITS 14
#endif
-
-#ifndef OPTIONS_VAR
-# define OPTIONS_VAR "GZIP"
+#ifndef HASH_BITS
+# define HASH_BITS 15
+ /* For portability to 16 bit machines, do not use values above 15. */
#endif
-#ifndef Z_SUFFIX
-# define Z_SUFFIX ".gz"
+#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 */
+#ifndef TOO_FAR
+# define TOO_FAR 4096
#endif
+/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */
-#ifdef MAX_EXT_CHARS
-# define MAX_SUFFIX MAX_EXT_CHARS
-#else
-# define MAX_SUFFIX 30
-#endif
- /* global buffers */
+/* ===========================================================================
+ * These types are not really 'char', 'short' and 'long'
+ */
+typedef uint8_t uch;
+typedef uint16_t ush;
+typedef uint32_t ulg;
+typedef int32_t lng;
-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);
+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.
+ */
-static int foreground; /* set if program run in foreground */
-static int method = DEFLATED; /* compression method */
-static int exit_code = OK; /* program exit code */
-static long time_stamp; /* original time stamp (modification time) */
-static char z_suffix[MAX_SUFFIX + 1]; /* default suffix (can be set with --suffix) */
+enum {
+ WINDOW_SIZE = 2 * WSIZE,
+/* window size, 2*WSIZE except for MMAP or BIG_MEM, where it is the
+ * input file length plus MIN_LOOKAHEAD.
+ */
-static int ifd; /* input file descriptor */
-static int ofd; /* output file descriptor */
-#ifdef DEBUG
-static unsigned insize; /* valid bytes in inbuf */
-#endif
-static unsigned outcnt; /* bytes in output buffer */
+ 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 uint32_t *crc_32_tab;
+ 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.
+ */
-/* Output a 16 bit value, lsb first */
-static void put_short(ush 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));
- }
-}
+ 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.
+ */
+
+ good_match = 32,
+/* Use a faster search when the previous match is longer than this */
-/* ========================================================================
- * Signal and error handler.
+/* 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 void abort_gzip(int ATTRIBUTE_UNUSED ignored)
-{
- exit(ERROR);
-}
-/* ===========================================================================
- * Clear input and output buffers
+ 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.
*/
-static void clear_bufs(void)
-{
- outcnt = 0;
-#ifdef DEBUG
- insize = 0;
-#endif
- bytes_in = 0L;
-}
+};
-/* ===========================================================================
- * Does the same as write(), but also handles partial pipe writes and checks
- * for error return.
+
+struct globals {
+
+ lng block_start;
+
+/* window position at the beginning of the current output block. Gets
+ * negative when the window is moved backwards.
*/
-static void write_buf(int fd, void *buf, unsigned cnt)
-{
- unsigned n;
+ unsigned ins_h; /* hash index of string to be inserted */
- while ((n = write(fd, buf, cnt)) != cnt) {
- if (n == (unsigned) (-1)) bb_error_msg_and_die(bb_msg_write_error);
- cnt -= n;
- buf = (void *) ((char *) buf + n);
- }
-}
+#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
+ */
-/* ===========================================================================
- * 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.
+ unsigned 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 uint32_t updcrc(uch * s, unsigned n)
-{
- static uint32_t crc = ~0; /* shift register contents */
- uint32_t c; /* temporary variable */
- if (s == NULL) {
- c = ~0;
- } else {
- c = crc;
- if (n)
- do {
- c = crc_32_tab[((int) c ^ (*s++)) & 0xff] ^ (c >> 8);
- } while (--n);
- }
- crc = c;
- return ~c;
-}
+ unsigned strstart; /* start of string to insert */
+ unsigned match_start; /* start of matching string */
+ unsigned lookahead; /* number of valid bytes ahead in window */
-/* 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.
+/* ===========================================================================
*/
+#define DECLARE(type, array, size) \
+ type * array
+#define ALLOC(type, array, size) \
+ array = xzalloc((size_t)(((size)+1L)/2) * 2*sizeof(type))
+#define FREE(array) \
+ do { free(array); array = NULL; } while (0)
+ /* global buffers */
-/*
- * 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.
- *
+ /* buffer for literals or lengths */
+ /* DECLARE(uch, l_buf, LIT_BUFSIZE); */
+ DECLARE(uch, l_buf, INBUFSIZ);
+
+ DECLARE(ush, d_buf, DIST_BUFSIZE);
+ DECLARE(uch, outbuf, OUTBUFSIZ);
+
+/* 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(uch, window, 2L * 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, prev, WSIZE); */
+ DECLARE(ush, prev, 1L << BITS);
+
+/* Heads of the hash chains or 0. */
+ /* DECLARE(Pos, head, 1<<HASH_BITS); */
+#define head (G1.prev + WSIZE) /* hash head (see deflate.c) */
+
+/* number of input bytes */
+ ulg isize; /* only 32 bits stored in .gz file */
+
+/* bbox always use stdin/stdout */
+#define ifd STDIN_FILENO /* input file descriptor */
+#define ofd STDOUT_FILENO /* output file descriptor */
+
+#ifdef DEBUG
+ unsigned insize; /* valid bytes in l_buf */
+#endif
+ unsigned outcnt; /* bytes in output buffer */
+
+ smallint eofile; /* flag set at end of input file */
/* ===========================================================================
* Local data used by the "bit string" routines.
*/
-static file_t zfile; /* output gzip file */
-
-static unsigned short bi_buf;
+ unsigned short bi_buf;
/* Output buffer. bits are inserted starting at the bottom (least significant
* bits).
*/
-#define Buf_size (8 * 2*sizeof(char))
+#undef BUF_SIZE
+#define BUF_SIZE (8 * sizeof(G1.bi_buf))
/* Number of bits used within bi_buf. (bi_buf might be implemented on
* more than 16 bits on some systems.)
*/
-static int bi_valid;
+ 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 */
+ ulg bits_sent; /* bit length of the compressed data */
#endif
+ /*uint32_t *crc_32_tab;*/
+ uint32_t crc; /* shift register contents */
+};
+
+#define G1 (*(ptr_to_globals - 1))
+
+
/* ===========================================================================
- * Initialize the bit string routines.
+ * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
+ * (used for the compressed data only)
*/
-static void bi_init(file_t zipfile)
+static void flush_outbuf(void)
{
- zfile = zipfile;
- bi_buf = 0;
- bi_valid = 0;
-#ifdef DEBUG
- bits_sent = 0L;
-#endif
+ if (G1.outcnt == 0)
+ return;
- /* Set the defaults for file compression. They are set by memcompress
- * for in-memory compression.
- */
- if (zfile != NO_FILE) {
- read_buf = file_read;
- }
+ xwrite(ofd, (char *) G1.outbuf, G1.outcnt);
+ G1.outcnt = 0;
}
+
/* ===========================================================================
- * 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)
+/* put_8bit is used for the compressed output */
+#define put_8bit(c) \
+do { \
+ G1.outbuf[G1.outcnt++] = (c); \
+ if (G1.outcnt == OUTBUFSIZ) flush_outbuf(); \
+} while (0)
+
+/* Output a 16 bit value, lsb first */
+static void put_16bit(ush w)
{
-#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;
+ if (G1.outcnt < OUTBUFSIZ - 2) {
+ G1.outbuf[G1.outcnt++] = w;
+ G1.outbuf[G1.outcnt++] = w >> 8;
} else {
- bi_buf |= value << bi_valid;
- bi_valid += length;
+ put_8bit(w);
+ put_8bit(w >> 8);
}
}
-/* ===========================================================================
- * 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)
+static void put_32bit(ulg n)
{
- unsigned res = 0;
-
- do {
- res |= code & 1;
- code >>= 1, res <<= 1;
- } while (--len > 0);
- return res >> 1;
+ put_16bit(n);
+ put_16bit(n >> 16);
}
/* ===========================================================================
- * Write out any remaining bits in an incomplete byte.
+ * 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 void bi_windup(void)
+static void updcrc(uch * s, unsigned n)
{
- 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
+ G1.crc = crc32_block_endian0(G1.crc, s, n, global_crc32_table /*G1.crc_32_tab*/);
}
-/* ===========================================================================
- * 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.
- *
- * ACKNOWLEDGMENTS
- *
- * 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 */
-
-enum {
- 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.
- */
-
- 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.
- */
- 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.
+ * 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 unsigned file_read(void *buf, unsigned size)
+{
+ unsigned len;
- good_match = 32,
-
-/* Use a faster search when the previous match is longer than this */
+ Assert(G1.insize == 0, "l_buf not empty");
+ len = safe_read(ifd, buf, size);
+ if (len == (unsigned)(-1) || len == 0)
+ return len;
-/* 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.
- */
-
- 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.
- */
-};
+ updcrc(buf, len);
+ G1.isize += len;
+ return len;
+}
-#define EQUAL 0
-/* result of memcmp for equal strings */
/* ===========================================================================
- * Prototypes for local functions.
+ * Send a value on a given number of bits.
+ * IN assertion: length <= 16 and value fits in length bits.
*/
-static void fill_window(void);
-
-static int longest_match(IPos cur_match);
-
+static void send_bits(int value, int length)
+{
#ifdef DEBUG
-static void check_match(IPos start, IPos match, int length);
+ Tracev((stderr, " l %2d v %4x ", length, value));
+ Assert(length > 0 && length <= 15, "invalid length");
+ G1.bits_sent += 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 (G1.bi_valid > (int) BUF_SIZE - length) {
+ G1.bi_buf |= (value << G1.bi_valid);
+ put_16bit(G1.bi_buf);
+ G1.bi_buf = (ush) value >> (BUF_SIZE - G1.bi_valid);
+ G1.bi_valid += length - BUF_SIZE;
+ } else {
+ G1.bi_buf |= value << G1.bi_valid;
+ G1.bi_valid += length;
+ }
+}
-/* ===========================================================================
- * 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
+ * Reverse the first len bits of a code, using straightforward code (a faster
+ * method would use a table)
+ * IN assertion: 1 <= len <= 15
*/
-static void lm_init(ush * flags)
+static unsigned bi_reverse(unsigned code, int len)
{
- unsigned j;
-
- /* Initialize the hash table. */
- memset(head, 0, 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);
+ unsigned res = 0;
- if (lookahead == 0 || lookahead == (unsigned) EOF) {
- eofile = 1, lookahead = 0;
- return;
+ while (1) {
+ res |= code & 1;
+ if (--len <= 0) return res;
+ code >>= 1;
+ res <<= 1;
}
- 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.
+/* ===========================================================================
+ * Write out any remaining bits in an incomplete byte.
*/
-static int longest_match(IPos cur_match)
+static void bi_windup(void)
{
- unsigned chain_length = max_chain_length; /* max hash chain length */
- uch *scan = window + strstart; /* current string */
- uch *match; /* matched string */
- 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
- uch *strend = window + strstart + MAX_MATCH;
- uch scan_end1 = scan[best_len - 1];
- 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;
+ if (G1.bi_valid > 8) {
+ put_16bit(G1.bi_buf);
+ } else if (G1.bi_valid > 0) {
+ put_8bit(G1.bi_buf);
}
- 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;
+ G1.bi_buf = 0;
+ G1.bi_valid = 0;
+#ifdef DEBUG
+ G1.bits_sent = (G1.bits_sent + 7) & ~7;
+#endif
}
-#ifdef DEBUG
+
/* ===========================================================================
- * Check that the match at match_start is indeed a match.
+ * Copy a stored block to the zip file, storing first the length and its
+ * one's complement if requested.
*/
-static void check_match(IPos start, IPos match, int length)
+static void copy_block(char *buf, unsigned len, int header)
{
- /* check that the match is indeed a match */
- if (memcmp((char *) window + match,
- (char *) window + start, length) != EQUAL) {
- bb_error_msg(" start %d, match %d, length %d", start, match, length);
- bb_error_msg("invalid match");
+ bi_windup(); /* align on byte boundary */
+
+ if (header) {
+ put_16bit(len);
+ put_16bit(~len);
+#ifdef DEBUG
+ G1.bits_sent += 2 * 16;
+#endif
}
- if (verbose > 1) {
- bb_error_msg("\\[%d,%d]", start - match, length);
- do {
- putc(window[start++], stderr);
- } while (--length != 0);
+#ifdef DEBUG
+ G1.bits_sent += (ulg) len << 3;
+#endif
+ while (len--) {
+ put_8bit(*buf++);
}
}
-#else
-# define check_match(start, match, length)
-#endif
+
/* ===========================================================================
* Fill the window when the lookahead becomes insufficient.
static void fill_window(void)
{
unsigned n, m;
- unsigned more =
- (unsigned) (window_size - (ulg) lookahead - (ulg) strstart);
+ unsigned more = WINDOW_SIZE - G1.lookahead - G1.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) {
+ if (more == (unsigned) -1) {
/* 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) {
+ } else if (G1.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");
+ Assert(WINDOW_SIZE == 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: */
+ memcpy(G1.window, G1.window + WSIZE, WSIZE);
+ G1.match_start -= WSIZE;
+ G1.strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
- block_start -= (long) WSIZE;
+ G1.block_start -= WSIZE;
for (n = 0; n < HASH_SIZE; n++) {
m = head[n];
- head[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
+ head[n] = (Pos) (m >= WSIZE ? m - WSIZE : 0);
}
for (n = 0; n < WSIZE; n++) {
- m = prev[n];
- prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : NIL);
+ m = G1.prev[n];
+ G1.prev[n] = (Pos) (m >= WSIZE ? m - WSIZE : 0);
/* 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;
+ if (!G1.eofile) {
+ n = file_read(G1.window + G1.strstart + G1.lookahead, more);
+ if (n == 0 || n == (unsigned) -1) {
+ G1.eofile = 1;
} else {
- lookahead += n;
+ G1.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(void)
-{
- 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 */
- 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.
+ * 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
*/
-/* 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.
+/* 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.
*/
-
-/* configuration */
-
-typedef struct dirent dir_type;
-
-/* ======================================================================== */
-int gzip_main(int argc, char **argv)
+static int longest_match(IPos cur_match)
{
- enum {
- OPT_tostdout = 0x1,
- OPT_force = 0x2,
- };
-
- unsigned opt;
- int result;
- int inFileNum;
- int outFileNum;
- struct stat statBuf;
- char *delFileName;
-
- opt = getopt32(argc, argv, "cf123456789qv" USE_GUNZIP("d"));
- //if (opt & 0x1) // -c
- //if (opt & 0x2) // -f
- /* Ignore 1-9 (compression level) options */
- //if (opt & 0x4) // -1
- //if (opt & 0x8) // -2
- //if (opt & 0x10) // -3
- //if (opt & 0x20) // -4
- //if (opt & 0x40) // -5
- //if (opt & 0x80) // -6
- //if (opt & 0x100) // -7
- //if (opt & 0x200) // -8
- //if (opt & 0x400) // -9
- //if (opt & 0x800) // -q
- //if (opt & 0x1000) // -v
-#if ENABLE_GUNZIP /* gunzip_main may not be visible... */
- if (opt & 0x2000) { // -d
- /* FIXME: getopt32 should not depend on optind */
- optind = 1;
- return gunzip_main(argc, argv);
- }
-#endif
+ unsigned chain_length = max_chain_length; /* max hash chain length */
+ uch *scan = G1.window + G1.strstart; /* current string */
+ uch *match; /* matched string */
+ int len; /* length of current match */
+ int best_len = G1.prev_length; /* best match length so far */
+ IPos limit = G1.strstart > (IPos) MAX_DIST ? G1.strstart - (IPos) MAX_DIST : 0;
+ /* Stop when cur_match becomes <= limit. To simplify the code,
+ * we prevent matches with the string of window index 0.
+ */
- foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
- if (foreground) {
- (void) signal(SIGINT, abort_gzip);
- }
-#ifdef SIGTERM
- if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
- (void) signal(SIGTERM, abort_gzip);
- }
-#endif
-#ifdef SIGHUP
- if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
- (void) signal(SIGHUP, abort_gzip);
- }
+/* 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
+ uch *strend = G1.window + G1.strstart + MAX_MATCH;
+ uch scan_end1 = scan[best_len - 1];
+ uch scan_end = scan[best_len];
- strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix) - 1);
-
- /* 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);
+ /* Do not waste too much time if we already have a good match: */
+ if (G1.prev_length >= good_match) {
+ chain_length >>= 2;
+ }
+ Assert(G1.strstart <= WINDOW_SIZE - MIN_LOOKAHEAD, "insufficient lookahead");
- /* Initialise the CRC32 table */
- crc_32_tab = crc32_filltable(0);
+ do {
+ Assert(cur_match < G1.strstart, "no future");
+ match = G1.window + cur_match;
- clear_bufs();
+ /* 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;
+ }
- if (optind == argc) {
- time_stamp = 0;
- zip(STDIN_FILENO, STDOUT_FILENO);
- } else {
- int i;
-
- for (i = optind; i < argc; i++) {
- char *path = NULL;
-
- clear_bufs();
- if (LONE_DASH(argv[i])) {
- time_stamp = 0;
- inFileNum = STDIN_FILENO;
- outFileNum = STDOUT_FILENO;
- } else {
- inFileNum = xopen(argv[i], O_RDONLY);
- if (fstat(inFileNum, &statBuf) < 0)
- bb_perror_msg_and_die("%s", argv[i]);
- time_stamp = statBuf.st_ctime;
-
- if (!(opt & OPT_tostdout)) {
- path = xasprintf("%s.gz", argv[i]);
-
- /* Open output file */
-#if defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1 && defined(O_NOFOLLOW)
- outFileNum =
- open(path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW);
-#else
- outFileNum = open(path, O_RDWR | O_CREAT | O_EXCL);
-#endif
- if (outFileNum < 0) {
- bb_perror_msg("%s", path);
- free(path);
- continue;
- }
-
- /* Set permissions on the file */
- fchmod(outFileNum, statBuf.st_mode);
- } else
- outFileNum = STDOUT_FILENO;
- }
+ /* 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++;
- if (path == NULL && isatty(outFileNum) && !(opt & OPT_force)) {
- bb_error_msg
- ("compressed data not written to a terminal. Use -f to force compression.");
- free(path);
- continue;
- }
+ /* 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);
- result = zip(inFileNum, outFileNum);
+ len = MAX_MATCH - (int) (strend - scan);
+ scan = strend - MAX_MATCH;
- if (path != NULL) {
- close(inFileNum);
- close(outFileNum);
+ if (len > best_len) {
+ G1.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 = G1.prev[cur_match & WMASK]) > limit
+ && --chain_length != 0);
- /* Delete the original file */
- if (result == OK)
- delFileName = argv[i];
- else
- delFileName = path;
+ return best_len;
+}
- if (unlink(delFileName) < 0)
- bb_perror_msg("%s", delFileName);
- }
- free(path);
- }
+#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(G1.window + match, G1.window + start, length) != 0) {
+ bb_error_msg(" start %d, match %d, length %d", start, match, length);
+ bb_error_msg("invalid match");
+ }
+ if (verbose > 1) {
+ bb_error_msg("\\[%d,%d]", start - match, length);
+ do {
+ bb_putchar_stderr(G1.window[start++]);
+ } while (--length != 0);
}
-
- return exit_code;
}
+#else
+# define check_match(start, match, length) ((void)0)
+#endif
+
/* trees.c -- output deflated data using Huffman coding
* Copyright (C) 1992-1993 Jean-loup Gailly
* terms of the GNU General Public License, see the file COPYING.
*/
-/*
- * PURPOSE
- *
+/* 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.
*
* (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.
* 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
+ * void ct_init()
+ * Allocate the match buffer, initialize the various tables [and save
* the location of the internal file attribute (ascii/binary) and
- * method (DEFLATE/STORE)
+ * method (DEFLATE/STORE) -- deleted in bbox]
*
- * void ct_tally (int dist, int lc);
+ * 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)
+ * ulg 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
#define BL_CODES 19
/* number of codes used to transfer the bit lengths */
-typedef uch extra_bits_t;
-
/* extra bits for each length code */
-static const extra_bits_t extra_lbits[LENGTH_CODES]
- = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4,
+static const uint8_t extra_lbits[LENGTH_CODES] ALIGN1 = {
+ 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
};
/* extra bits for each distance code */
-static const extra_bits_t extra_dbits[D_CODES]
- = { 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9,
+static const uint8_t extra_dbits[D_CODES] ALIGN1 = {
+ 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
};
/* extra bits for each bit length code */
-static const extra_bits_t extra_blbits[BL_CODES]
-= { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
+static const uint8_t extra_blbits[BL_CODES] ALIGN1 = {
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 7 };
+
+/* number of codes at each bit length for an optimal tree */
+static const uint8_t bl_order[BL_CODES] ALIGN1 = {
+ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
#define STORED_BLOCK 0
#define STATIC_TREES 1
* 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 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 {
#define Dad dl.dad
#define Len dl.len
-#define HEAP_SIZE (2*L_CODES+1)
+#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 */
+typedef struct tree_desc {
+ ct_data *dyn_tree; /* the dynamic tree */
+ ct_data *static_tree; /* corresponding static tree or NULL */
+ const uint8_t *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;
+
+struct globals2 {
+
+ ush heap[HEAP_SIZE]; /* heap used to build the Huffman trees */
+ int heap_len; /* number of elements in the heap */
+ int heap_max; /* element of largest frequency */
-static ct_data static_ltree[L_CODES + 2];
+/* 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.
+ */
+
+ ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */
+ ct_data dyn_dtree[2 * D_CODES + 1]; /* distance tree */
+
+ 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
* below).
*/
-static ct_data static_dtree[D_CODES];
+ 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];
+ 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 extra_bits_t *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 };
+ tree_desc l_desc;
+ tree_desc d_desc;
+ tree_desc bl_desc;
-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 };
+ ush bl_count[MAX_BITS + 1];
/* 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];
+ 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];
+ uch length_code[MAX_MATCH - MIN_MATCH + 1];
/* length code for each normalized match length (0 == MIN_MATCH) */
-static uch dist_code[512];
+ 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];
+ int base_length[LENGTH_CODES];
/* First normalized length for each code (0 = MIN_MATCH) */
-static int base_dist[D_CODES];
+ 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)];
+ 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 */
+ unsigned last_lit; /* running index in l_buf */
+ unsigned last_dist; /* running index in d_buf */
+ unsigned last_flags; /* running index in flag_buf */
+ uch flags; /* current flags not yet saved in flag_buf */
+ 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 */
+ ulg opt_len; /* bit length of current block with optimal trees */
+ ulg static_len; /* bit length of current block with static trees */
-static ulg compressed_len; /* total bit length of compressed file */
+ ulg compressed_len; /* total bit length of compressed file */
+};
+#define G2ptr ((struct globals2*)(ptr_to_globals))
+#define G2 (*G2ptr)
-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 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) bb_error_msg("\ncd %3d ",(c)); \
- send_bits(tree[c].Code, tree[c].Len); }
+/* Send a code of the given tree. c and tree must not have side effects */
+# define SEND_CODE(c, tree) send_bits(tree[c].Code, tree[c].Len)
+#else
+# define SEND_CODE(c, tree) \
+{ \
+ if (verbose > 1) bb_error_msg("\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)])
+#define D_CODE(dist) \
+ ((dist) < 256 ? G2.dist_code[dist] : G2.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.
*/
-/* 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(void)
{
- int n; /* iterates over tree elements */
+ int n; /* iterates over tree elements */
/* Initialize the trees. */
for (n = 0; n < L_CODES; n++)
- dyn_ltree[n].Freq = 0;
+ G2.dyn_ltree[n].Freq = 0;
for (n = 0; n < D_CODES; n++)
- dyn_dtree[n].Freq = 0;
+ G2.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 */
+ G2.bl_tree[n].Freq = 0;
-
-/* ===========================================================================
- * 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); \
+ G2.dyn_ltree[END_BLOCK].Freq = 1;
+ G2.opt_len = G2.static_len = 0;
+ G2.last_lit = G2.last_dist = G2.last_flags = 0;
+ G2.flags = 0;
+ G2.flag_bit = 1;
}
-/* ===========================================================================
- * 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,
* when the heap property is re-established (each father smaller than its
* two sons).
*/
+
+/* 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 && G2.depth[n] <= G2.depth[m]))
+
static void pqdownheap(ct_data * tree, int k)
{
- int v = heap[k];
+ int v = G2.heap[k];
int j = k << 1; /* left son of k */
- while (j <= heap_len) {
+ while (j <= G2.heap_len) {
/* Set j to the smallest of the two sons: */
- if (j < heap_len && smaller(tree, heap[j + 1], heap[j]))
+ if (j < G2.heap_len && SMALLER(tree, G2.heap[j + 1], G2.heap[j]))
j++;
/* Exit if v is smaller than both sons */
- if (smaller(tree, v, heap[j]))
+ if (SMALLER(tree, v, G2.heap[j]))
break;
/* Exchange v with the smallest son */
- heap[k] = heap[j];
+ G2.heap[k] = G2.heap[j];
k = j;
/* And continue down the tree, setting j to the left son of k */
j <<= 1;
}
- heap[k] = v;
+ G2.heap[k] = v;
}
+
/* ===========================================================================
* Compute the optimal bit lengths for a tree and update the total bit length
* for the current block.
static void gen_bitlen(tree_desc * desc)
{
ct_data *tree = desc->dyn_tree;
- const extra_bits_t *extra = desc->extra_bits;
+ const uint8_t *extra = desc->extra_bits;
int base = desc->extra_base;
int max_code = desc->max_code;
int max_length = desc->max_length;
int overflow = 0; /* number of elements with bit length too large */
for (bits = 0; bits <= MAX_BITS; bits++)
- bl_count[bits] = 0;
+ G2.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 */
+ tree[G2.heap[G2.heap_max]].Len = 0; /* root of the heap */
- for (h = heap_max + 1; h < HEAP_SIZE; h++) {
- n = heap[h];
+ for (h = G2.heap_max + 1; h < HEAP_SIZE; h++) {
+ n = G2.heap[h];
bits = tree[tree[n].Dad].Len + 1;
- if (bits > max_length)
- bits = max_length, overflow++;
+ 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]++;
+ G2.bl_count[bits]++;
xbits = 0;
if (n >= base)
xbits = extra[n - base];
f = tree[n].Freq;
- opt_len += (ulg) f *(bits + xbits);
+ G2.opt_len += (ulg) f *(bits + xbits);
if (stree)
- static_len += (ulg) f *(stree[n].Len + xbits);
+ G2.static_len += (ulg) f * (stree[n].Len + xbits);
}
if (overflow == 0)
return;
/* Find the first bit length which could increase: */
do {
bits = max_length - 1;
- while (bl_count[bits] == 0)
+ while (G2.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]--;
+ G2.bl_count[bits]--; /* move one leaf down the tree */
+ G2.bl_count[bits + 1] += 2; /* move one overflow item as its brother */
+ G2.bl_count[max_length]--;
/* The brother of the overflow item also moves one step up,
* but this does not affect bl_count[max_length]
*/
* from 'ar' written by Haruhiko Okumura.)
*/
for (bits = max_length; bits != 0; bits--) {
- n = bl_count[bits];
+ n = G2.bl_count[bits];
while (n != 0) {
- m = heap[--h];
+ m = G2.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;
+ Trace((stderr, "code %d bits %d->%d\n", m, tree[m].Len, bits));
+ G2.opt_len += ((int32_t) bits - tree[m].Len) * tree[m].Freq;
+ tree[m].Len = bits;
}
n--;
}
}
}
+
/* ===========================================================================
* Generate the codes for a given tree and bit counts (which need not be
* optimal).
* without bit reversal.
*/
for (bits = 1; bits <= MAX_BITS; bits++) {
- next_code[bits] = code = (code + bl_count[bits - 1]) << 1;
+ next_code[bits] = code = (code + G2.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");
+ Assert(code + G2.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++) {
/* Now reverse the bits */
tree[n].Code = bi_reverse(next_code[len]++, len);
- Tracec(tree != static_ltree,
+ Tracec(tree != G2.static_ltree,
(stderr, "\nn %3d %c l %2d c %4x (%x) ", n,
- (isgraph(n) ? n : ' '), len, tree[n].Code,
+ (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.
* 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.
*/
+
+/* Remove the smallest element from the heap and recreate the heap with
+ * one less element. Updates heap and heap_len. */
+
+#define SMALLEST 1
+/* Index within the heap array of least frequent node in the Huffman tree */
+
+#define PQREMOVE(tree, top) \
+do { \
+ top = G2.heap[SMALLEST]; \
+ G2.heap[SMALLEST] = G2.heap[G2.heap_len--]; \
+ pqdownheap(tree, SMALLEST); \
+} while (0)
+
static void build_tree(tree_desc * desc)
{
ct_data *tree = desc->dyn_tree;
* 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;
+ G2.heap_len = 0;
+ G2.heap_max = HEAP_SIZE;
for (n = 0; n < elems; n++) {
if (tree[n].Freq != 0) {
- heap[++heap_len] = max_code = n;
- depth[n] = 0;
+ G2.heap[++G2.heap_len] = max_code = n;
+ G2.depth[n] = 0;
} else {
tree[n].Len = 0;
}
* 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);
+ while (G2.heap_len < 2) {
+ int new = G2.heap[++G2.heap_len] = (max_code < 2 ? ++max_code : 0);
tree[new].Freq = 1;
- depth[new] = 0;
- opt_len--;
+ G2.depth[new] = 0;
+ G2.opt_len--;
if (stree)
- static_len -= stree[new].Len;
+ G2.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--)
+ for (n = G2.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 */
+ PQREMOVE(tree, n); /* n = node of least frequency */
+ m = G2.heap[SMALLEST]; /* m = node of next least frequency */
- heap[--heap_max] = n; /* keep the nodes sorted by frequency */
- heap[--heap_max] = m;
+ G2.heap[--G2.heap_max] = n; /* keep the nodes sorted by frequency */
+ G2.heap[--G2.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);
+ G2.depth[node] = MAX(G2.depth[n], G2.depth[m]) + 1;
tree[n].Dad = tree[m].Dad = (ush) node;
#ifdef DUMP_BL_TREE
- if (tree == bl_tree) {
+ if (tree == G2.bl_tree) {
bb_error_msg("\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++;
+ G2.heap[SMALLEST] = node++;
pqdownheap(tree, SMALLEST);
- } while (heap_len >= 2);
+ } while (G2.heap_len >= 2);
- heap[--heap_max] = heap[SMALLEST];
+ G2.heap[--G2.heap_max] = G2.heap[SMALLEST];
/* At this point, the fields freq and dad are set. We can now
* generate the bit lengths.
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
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 */
+ if (nextlen == 0) {
+ max_count = 138;
+ min_count = 3;
+ }
+ tree[max_code + 1].Len = 0xffff; /* guard */
for (n = 0; n <= max_code; n++) {
curlen = nextlen;
nextlen = tree[n + 1].Len;
- if (++count < max_count && curlen == nextlen) {
+ if (++count < max_count && curlen == nextlen)
continue;
- } else if (count < min_count) {
- bl_tree[curlen].Freq += count;
+
+ if (count < min_count) {
+ G2.bl_tree[curlen].Freq += count;
} else if (curlen != 0) {
if (curlen != prevlen)
- bl_tree[curlen].Freq++;
- bl_tree[REP_3_6].Freq++;
+ G2.bl_tree[curlen].Freq++;
+ G2.bl_tree[REP_3_6].Freq++;
} else if (count <= 10) {
- bl_tree[REPZ_3_10].Freq++;
+ G2.bl_tree[REPZ_3_10].Freq++;
} else {
- bl_tree[REPZ_11_138].Freq++;
+ G2.bl_tree[REPZ_11_138].Freq++;
}
count = 0;
prevlen = curlen;
+
+ max_count = 7;
+ min_count = 4;
if (nextlen == 0) {
- max_count = 138, min_count = 3;
+ max_count = 138;
+ min_count = 3;
} else if (curlen == nextlen) {
- max_count = 6, min_count = 3;
- } else {
- max_count = 7, min_count = 4;
+ max_count = 6;
+ min_count = 3;
}
}
}
+
/* ===========================================================================
* Send a literal or distance tree in compressed form, using the codes in
* bl_tree.
continue;
} else if (count < min_count) {
do {
- send_code(curlen, bl_tree);
- } while (--count != 0);
-
+ SEND_CODE(curlen, G2.bl_tree);
+ } while (--count);
} else if (curlen != 0) {
if (curlen != prevlen) {
- send_code(curlen, bl_tree);
+ SEND_CODE(curlen, G2.bl_tree);
count--;
}
Assert(count >= 3 && count <= 6, " 3_6?");
- send_code(REP_3_6, bl_tree);
+ SEND_CODE(REP_3_6, G2.bl_tree);
send_bits(count - 3, 2);
-
} else if (count <= 10) {
- send_code(REPZ_3_10, bl_tree);
+ SEND_CODE(REPZ_3_10, G2.bl_tree);
send_bits(count - 3, 3);
-
} else {
- send_code(REPZ_11_138, bl_tree);
+ SEND_CODE(REPZ_11_138, G2.bl_tree);
send_bits(count - 11, 7);
}
count = 0;
prevlen = curlen;
if (nextlen == 0) {
- max_count = 138, min_count = 3;
+ max_count = 138;
+ min_count = 3;
} else if (curlen == nextlen) {
- max_count = 6, min_count = 3;
+ max_count = 6;
+ min_count = 3;
} else {
- max_count = 7, min_count = 4;
+ 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.
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);
+ scan_tree(G2.dyn_ltree, G2.l_desc.max_code);
+ scan_tree(G2.dyn_dtree, G2.d_desc.max_code);
/* Build the bit length tree: */
- build_tree((tree_desc *) (&bl_desc));
+ build_tree(&G2.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.
*/
* 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)
+ if (G2.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));
+ G2.opt_len += 3 * (max_blindex + 1) + 5 + 5 + 4;
+ Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", G2.opt_len, G2.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.
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);
+ send_bits(G2.bl_tree[bl_order[rank]].Len, 3);
+ }
+ Tracev((stderr, "\nbl tree: sent %ld", G1.bits_sent));
+
+ send_tree((ct_data *) G2.dyn_ltree, lcodes - 1); /* send the literal tree */
+ Tracev((stderr, "\nlit tree: sent %ld", G1.bits_sent));
+
+ send_tree((ct_data *) G2.dyn_dtree, dcodes - 1); /* send the distance tree */
+ Tracev((stderr, "\ndist tree: sent %ld", G1.bits_sent));
+}
+
+
+/* ===========================================================================
+ * 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)
+{
+ G1.l_buf[G2.last_lit++] = lc;
+ if (dist == 0) {
+ /* lc is the unmatched char */
+ G2.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"
+ );
+
+ G2.dyn_ltree[G2.length_code[lc] + LITERALS + 1].Freq++;
+ G2.dyn_dtree[D_CODE(dist)].Freq++;
+
+ G1.d_buf[G2.last_dist++] = dist;
+ G2.flags |= G2.flag_bit;
+ }
+ G2.flag_bit <<= 1;
+
+ /* Output the flags if they fill a byte: */
+ if ((G2.last_lit & 7) == 0) {
+ G2.flag_buf[G2.last_flags++] = G2.flags;
+ G2.flags = 0;
+ G2.flag_bit = 1;
+ }
+ /* Try to guess if it is profitable to stop the current block here */
+ if ((G2.last_lit & 0xfff) == 0) {
+ /* Compute an upper bound for the compressed length */
+ ulg out_length = G2.last_lit * 8L;
+ ulg in_length = (ulg) G1.strstart - G1.block_start;
+ int dcode;
+
+ for (dcode = 0; dcode < D_CODES; dcode++) {
+ out_length += G2.dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
+ }
+ out_length >>= 3;
+ Trace((stderr,
+ "\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
+ G2.last_lit, G2.last_dist, in_length, out_length,
+ 100L - out_length * 100L / in_length));
+ if (G2.last_dist < G2.last_lit / 2 && out_length < in_length / 2)
+ return 1;
}
- Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
+ return (G2.last_lit == LIT_BUFSIZE - 1 || G2.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_tree((ct_data *) dyn_ltree, lcodes - 1); /* send the literal tree */
- Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
+/* ===========================================================================
+ * 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 (G2.last_lit != 0) do {
+ if ((lx & 7) == 0)
+ flag = G2.flag_buf[fx++];
+ lc = G1.l_buf[lx++];
+ if ((flag & 1) == 0) {
+ SEND_CODE(lc, ltree); /* send a literal byte */
+ Tracecv(lc > ' ', (stderr, " '%c' ", lc));
+ } else {
+ /* Here, lc is the match length - MIN_MATCH */
+ code = G2.length_code[lc];
+ SEND_CODE(code + LITERALS + 1, ltree); /* send the length code */
+ extra = extra_lbits[code];
+ if (extra != 0) {
+ lc -= G2.base_length[code];
+ send_bits(lc, extra); /* send the extra length bits */
+ }
+ dist = G1.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 -= G2.base_dist[code];
+ send_bits(dist, extra); /* send the extra distance bits */
+ }
+ } /* literal or match pair ? */
+ flag >>= 1;
+ } while (lx < G2.last_lit);
- send_tree((ct_data *) dyn_dtree, dcodes - 1); /* send the distance tree */
- Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
+ SEND_CODE(END_BLOCK, ltree);
}
+
/* ===========================================================================
* 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
*/
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 */
+ 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();
+ G2.flag_buf[G2.last_flags] = G2.flags; /* Save the flags for the last 8 items */
/* 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(&G2.l_desc);
+ Tracev((stderr, "\nlit data: dyn %ld, stat %ld", G2.opt_len, G2.static_len));
- build_tree((tree_desc *) (&d_desc));
- Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
+ build_tree(&G2.d_desc);
+ Tracev((stderr, "\ndist data: dyn %ld, stat %ld", G2.opt_len, G2.static_len));
/* At this point, opt_len and static_len are the total bit lengths of
* the compressed block data, excluding the tree representations.
*/
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;
+ opt_lenb = (G2.opt_len + 3 + 7) >> 3;
+ static_lenb = (G2.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));
+ "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
+ opt_lenb, G2.opt_len, static_lenb, G2.static_len, stored_len,
+ G2.last_lit, G2.last_dist));
if (static_lenb <= opt_lenb)
opt_lenb = static_lenb;
* 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()) {
+ if (stored_len <= opt_lenb && eof && G2.compressed_len == 0L && seekable()) {
/* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
- if (buf == (char *) 0)
+ if (buf == NULL)
bb_error_msg("block vanished");
copy_block(buf, (unsigned) stored_len, 0); /* without header */
- compressed_len = stored_len << 3;
- *file_method = STORED;
+ G2.compressed_len = stored_len << 3;
- } else if (stored_len + 4 <= opt_lenb && buf != (char *) 0) {
+ } else if (stored_len + 4 <= opt_lenb && buf != NULL) {
/* 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
* 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;
+ G2.compressed_len = (G2.compressed_len + 3 + 7) & ~7L;
+ G2.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;
+ compress_block((ct_data *) G2.static_ltree, (ct_data *) G2.static_dtree);
+ G2.compressed_len += 3 + G2.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;
+ send_all_trees(G2.l_desc.max_code + 1, G2.d_desc.max_code + 1,
+ max_blindex + 1);
+ compress_block((ct_data *) G2.dyn_ltree, (ct_data *) G2.dyn_dtree);
+ G2.compressed_len += 3 + G2.opt_len;
}
- Assert(compressed_len == bits_sent, "bad compressed size");
+ Assert(G2.compressed_len == G1.bits_sent, "bad compressed size");
init_block();
if (eof) {
bi_windup();
- compressed_len += 7; /* align on byte boundary */
+ G2.compressed_len += 7; /* align on byte boundary */
}
- Tracev((stderr, "\ncomprlen %lu(%lu) ", compressed_len >> 3,
- compressed_len - 7 * eof));
+ Tracev((stderr, "\ncomprlen %lu(%lu) ", G2.compressed_len >> 3,
+ G2.compressed_len - 7 * eof));
- return compressed_len >> 3;
+ return G2.compressed_len >> 3;
}
+
/* ===========================================================================
- * Save the match info and tally the frequency counts. Return true if
- * the current block must be flushed.
+ * Update a hash value with the given input byte
+ * IN assertion: all calls 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.
*/
-static int ct_tally(int dist, int lc)
+#define UPDATE_HASH(h, c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
+
+
+/* ===========================================================================
+ * 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.
+ *
+ * Processes a new input file and return its compressed length. Sets
+ * the compressed length, crc, deflate flags and internal file
+ * attributes.
+ */
+
+/* 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( \
+ G1.block_start >= 0L \
+ ? (char*)&G1.window[(unsigned)G1.block_start] \
+ : (char*)NULL, \
+ (ulg)G1.strstart - G1.block_start, \
+ (eof) \
+ )
+
+/* 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 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) \
+do { \
+ UPDATE_HASH(G1.ins_h, G1.window[(s) + MIN_MATCH-1]); \
+ G1.prev[(s) & WMASK] = match_head = head[G1.ins_h]; \
+ head[G1.ins_h] = (s); \
+} while (0)
+
+static ulg deflate(void)
{
- 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");
+ 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 */
+ unsigned match_length = MIN_MATCH - 1; /* length of best match */
- dyn_ltree[length_code[lc] + LITERALS + 1].Freq++;
- dyn_dtree[d_code(dist)].Freq++;
+ /* Process the input block. */
+ while (G1.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(G1.strstart, hash_head);
- d_buf[last_dist++] = (ush) dist;
- flags |= flag_bit;
- }
- flag_bit <<= 1;
+ /* Find the longest match, discarding those <= prev_length.
+ */
+ G1.prev_length = match_length;
+ prev_match = G1.match_start;
+ match_length = MIN_MATCH - 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;
+ if (hash_head != 0 && G1.prev_length < max_lazy_match
+ && G1.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 > G1.lookahead)
+ match_length = G1.lookahead;
- for (dcode = 0; dcode < D_CODES; dcode++) {
- out_length +=
- (ulg) dyn_dtree[dcode].Freq * (5L + extra_dbits[dcode]);
+ /* Ignore a length 3 match if it is too distant: */
+ if (match_length == MIN_MATCH && G1.strstart - G1.match_start > TOO_FAR) {
+ /* If prev_match is also MIN_MATCH, G1.match_start is garbage
+ * but we will ignore the current match anyway.
+ */
+ match_length--;
+ }
}
- 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;
+ /* If there was a match at the previous step and the current
+ * match is not better, output the previous match:
+ */
+ if (G1.prev_length >= MIN_MATCH && match_length <= G1.prev_length) {
+ check_match(G1.strstart - 1, prev_match, G1.prev_length);
+ flush = ct_tally(G1.strstart - 1 - prev_match, G1.prev_length - MIN_MATCH);
+
+ /* Insert in hash table all strings up to the end of the match.
+ * strstart-1 and strstart are already inserted.
+ */
+ G1.lookahead -= G1.prev_length - 1;
+ G1.prev_length -= 2;
+ do {
+ G1.strstart++;
+ INSERT_STRING(G1.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 (--G1.prev_length != 0);
+ match_available = 0;
+ match_length = MIN_MATCH - 1;
+ G1.strstart++;
+ if (flush) {
+ FLUSH_BLOCK(0);
+ G1.block_start = G1.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", G1.window[G1.strstart - 1]));
+ if (ct_tally(0, G1.window[G1.strstart - 1])) {
+ FLUSH_BLOCK(0);
+ G1.block_start = G1.strstart;
+ }
+ G1.strstart++;
+ G1.lookahead--;
+ } else {
+ /* There is no previous match to compare with, wait for
+ * the next step to decide.
+ */
+ match_available = 1;
+ G1.strstart++;
+ G1.lookahead--;
+ }
+ Assert(G1.strstart <= G1.isize && lookahead <= G1.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 (G1.lookahead < MIN_LOOKAHEAD && !G1.eofile)
+ fill_window();
}
- 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.
- */
+ if (match_available)
+ ct_tally(0, G1.window[G1.strstart - 1]);
+
+ return FLUSH_BLOCK(1); /* eof */
}
+
/* ===========================================================================
- * Send the block data compressed using the given Huffman trees
+ * Initialize the bit string routines.
*/
-static void compress_block(ct_data * ltree, ct_data * dtree)
+static void bi_init(void)
{
- 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);
+ G1.bi_buf = 0;
+ G1.bi_valid = 0;
+#ifdef DEBUG
+ G1.bits_sent = 0L;
+#endif
}
+
/* ===========================================================================
- * 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).
+ * Initialize the "longest match" routines for a new file
*/
-static void set_file_type(void)
+static void lm_init(ush * flagsp)
{
- 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) {
- bb_error_msg("-l used on binary file");
+ unsigned j;
+
+ /* Initialize the hash table. */
+ memset(head, 0, HASH_SIZE * sizeof(*head));
+ /* prev will be initialized on the fly */
+
+ /* speed options for the general purpose bit flag */
+ *flagsp |= 2; /* FAST 4, SLOW 2 */
+ /* ??? reduce max_chain_length for binary files */
+
+ G1.strstart = 0;
+ G1.block_start = 0L;
+
+ G1.lookahead = file_read(G1.window,
+ sizeof(int) <= 2 ? (unsigned) WSIZE : 2 * WSIZE);
+
+ if (G1.lookahead == 0 || G1.lookahead == (unsigned) -1) {
+ G1.eofile = 1;
+ G1.lookahead = 0;
+ return;
}
+ G1.eofile = 0;
+ /* Make sure that we always have enough lookahead. This is important
+ * if input comes from a device such as a tty.
+ */
+ while (G1.lookahead < MIN_LOOKAHEAD && !G1.eofile)
+ fill_window();
+
+ G1.ins_h = 0;
+ for (j = 0; j < MIN_MATCH - 1; j++)
+ UPDATE_HASH(G1.ins_h, G1.window[j]);
+ /* If lookahead < MIN_MATCH, ins_h is garbage, but this is
+ * not important since only literal bytes will be emitted.
+ */
}
-/* 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.
+
+/* ===========================================================================
+ * Allocate the match buffer, initialize the various tables and save the
+ * location of the internal file attribute (ascii/binary) and method
+ * (DEFLATE/STORE).
+ * One callsite in zip()
*/
+static void ct_init(void)
+{
+ int n; /* iterates over tree elements */
+ int length; /* length value */
+ int code; /* code value */
+ int dist; /* distance index */
+ G2.compressed_len = 0L;
-static uint32_t crc; /* crc on uncompressed file data */
-static long header_bytes; /* number of bytes in gzip header */
+#ifdef NOT_NEEDED
+ if (G2.static_dtree[0].Len != 0)
+ return; /* ct_init already called */
+#endif
-static void put_long(ulg n)
-{
- put_short((n) & 0xffff);
- put_short(((ulg) (n)) >> 16);
+ /* Initialize the mapping length (0..255) -> length code (0..28) */
+ length = 0;
+ for (code = 0; code < LENGTH_CODES - 1; code++) {
+ G2.base_length[code] = length;
+ for (n = 0; n < (1 << extra_lbits[code]); n++) {
+ G2.length_code[length++] = 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:
+ */
+ G2.length_code[length - 1] = code;
+
+ /* Initialize the mapping dist (0..32K) -> dist code (0..29) */
+ dist = 0;
+ for (code = 0; code < 16; code++) {
+ G2.base_dist[code] = dist;
+ for (n = 0; n < (1 << extra_dbits[code]); n++) {
+ G2.dist_code[dist++] = code;
+ }
+ }
+ Assert(dist == 256, "ct_init: dist != 256");
+ dist >>= 7; /* from now on, all distances are divided by 128 */
+ for (; code < D_CODES; code++) {
+ G2.base_dist[code] = dist << 7;
+ for (n = 0; n < (1 << (extra_dbits[code] - 7)); n++) {
+ G2.dist_code[256 + dist++] = code;
+ }
+ }
+ Assert(dist == 256, "ct_init: 256+dist != 512");
+
+ /* Construct the codes of the static literal tree */
+ /* already zeroed - it's in bss
+ for (n = 0; n <= MAX_BITS; n++)
+ G2.bl_count[n] = 0; */
+
+ n = 0;
+ while (n <= 143) {
+ G2.static_ltree[n++].Len = 8;
+ G2.bl_count[8]++;
+ }
+ while (n <= 255) {
+ G2.static_ltree[n++].Len = 9;
+ G2.bl_count[9]++;
+ }
+ while (n <= 279) {
+ G2.static_ltree[n++].Len = 7;
+ G2.bl_count[7]++;
+ }
+ while (n <= 287) {
+ G2.static_ltree[n++].Len = 8;
+ G2.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 *) G2.static_ltree, L_CODES + 1);
+
+ /* The static distance tree is trivial: */
+ for (n = 0; n < D_CODES; n++) {
+ G2.static_dtree[n].Len = 5;
+ G2.static_dtree[n].Code = bi_reverse(n, 5);
+ }
+
+ /* Initialize the first block of the first file: */
+ init_block();
}
-/* put_header_byte is used for the compressed output
- * - for the initial 4 bytes that can't overflow the buffer.
- */
-#define put_header_byte(c) {outbuf[outcnt++]=(uch)(c);}
/* ===========================================================================
* 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)
+
+static void zip(ulg time_stamp)
{
- uch my_flags = 0; /* general purpose bit flags */
- ush attr = 0; /* ascii/binary flag */
- ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
+ ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
- ifd = in;
- ofd = out;
- outcnt = 0;
+ G1.outcnt = 0;
/* Write the header to the gzip file. See algorithm.doc for the format */
-
- method = DEFLATED;
- put_header_byte(GZIP_MAGIC[0]); /* magic header */
- put_header_byte(GZIP_MAGIC[1]);
- put_header_byte(DEFLATED); /* compression method */
-
- put_header_byte(my_flags); /* general flags */
- put_long(time_stamp);
+ /* magic header for gzip files: 1F 8B */
+ /* compression method: 8 (DEFLATED) */
+ /* general flags: 0 */
+ put_32bit(0x00088b1f);
+ put_32bit(time_stamp);
/* Write deflated file to zip file */
- crc = updcrc(0, 0);
+ G1.crc = ~0;
- bi_init(out);
- ct_init(&attr, &method);
+ bi_init();
+ ct_init();
lm_init(&deflate_flags);
- put_byte((uch) deflate_flags); /* extra flags */
- put_byte(OS_CODE); /* OS identifier */
-
- header_bytes = (long) outcnt;
+ put_8bit(deflate_flags); /* extra flags */
+ put_8bit(3); /* OS identifier = 3 (Unix) */
- (void) deflate();
+ deflate();
/* Write the crc and uncompressed size */
- put_long(crc);
- put_long(isize);
- header_bytes += 2 * sizeof(long);
+ put_32bit(~G1.crc);
+ put_32bit(G1.isize);
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)
+/* ======================================================================== */
+static
+IF_DESKTOP(long long) int FAST_FUNC pack_gzip(transformer_aux_data_t *aux UNUSED_PARAM)
{
- unsigned len;
-
- Assert(insize == 0, "inbuf not empty");
+ struct stat s;
- 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;
+ /* Clear input and output buffers */
+ G1.outcnt = 0;
+#ifdef DEBUG
+ G1.insize = 0;
+#endif
+ G1.isize = 0;
+
+ /* Reinit G2.xxx */
+ memset(&G2, 0, sizeof(G2));
+ G2.l_desc.dyn_tree = G2.dyn_ltree;
+ G2.l_desc.static_tree = G2.static_ltree;
+ G2.l_desc.extra_bits = extra_lbits;
+ G2.l_desc.extra_base = LITERALS + 1;
+ G2.l_desc.elems = L_CODES;
+ G2.l_desc.max_length = MAX_BITS;
+ //G2.l_desc.max_code = 0;
+ G2.d_desc.dyn_tree = G2.dyn_dtree;
+ G2.d_desc.static_tree = G2.static_dtree;
+ G2.d_desc.extra_bits = extra_dbits;
+ //G2.d_desc.extra_base = 0;
+ G2.d_desc.elems = D_CODES;
+ G2.d_desc.max_length = MAX_BITS;
+ //G2.d_desc.max_code = 0;
+ G2.bl_desc.dyn_tree = G2.bl_tree;
+ //G2.bl_desc.static_tree = NULL;
+ G2.bl_desc.extra_bits = extra_blbits,
+ //G2.bl_desc.extra_base = 0;
+ G2.bl_desc.elems = BL_CODES;
+ G2.bl_desc.max_length = MAX_BL_BITS;
+ //G2.bl_desc.max_code = 0;
+
+ s.st_ctime = 0;
+ fstat(STDIN_FILENO, &s);
+ zip(s.st_ctime);
+ return 0;
}
-/* ===========================================================================
- * Write the output buffer outbuf[0..outcnt-1] and update bytes_out.
- * (used for the compressed data only)
- */
-static void flush_outbuf(void)
+#if ENABLE_FEATURE_GZIP_LONG_OPTIONS
+static const char gzip_longopts[] ALIGN1 =
+ "stdout\0" No_argument "c"
+ "to-stdout\0" No_argument "c"
+ "force\0" No_argument "f"
+ "verbose\0" No_argument "v"
+#if ENABLE_GUNZIP
+ "decompress\0" No_argument "d"
+ "uncompress\0" No_argument "d"
+ "test\0" No_argument "t"
+#endif
+ "quiet\0" No_argument "q"
+ "fast\0" No_argument "1"
+ "best\0" No_argument "9"
+ ;
+#endif
+
+/*
+ * Linux kernel build uses gzip -d -n. We accept and ignore -n.
+ * Man page says:
+ * -n --no-name
+ * gzip: do not save the original file name and time stamp.
+ * (The original name is always saved if the name had to be truncated.)
+ * gunzip: do not restore the original file name/time even if present
+ * (remove only the gzip suffix from the compressed file name).
+ * This option is the default when decompressing.
+ * -N --name
+ * gzip: always save the original file name and time stamp (this is the default)
+ * gunzip: restore the original file name and time stamp if present.
+ */
+
+int gzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+#if ENABLE_GUNZIP
+int gzip_main(int argc, char **argv)
+#else
+int gzip_main(int argc UNUSED_PARAM, char **argv)
+#endif
{
- if (outcnt == 0)
- return;
+ unsigned opt;
+
+#if ENABLE_FEATURE_GZIP_LONG_OPTIONS
+ applet_long_options = gzip_longopts;
+#endif
+ /* Must match bbunzip's constants OPT_STDOUT, OPT_FORCE! */
+ opt = getopt32(argv, "cfv" IF_GUNZIP("dt") "q123456789n");
+#if ENABLE_GUNZIP /* gunzip_main may not be visible... */
+ if (opt & 0x18) // -d and/or -t
+ return gunzip_main(argc, argv);
+#endif
+ option_mask32 &= 0x7; /* ignore -q, -0..9 */
+ //if (opt & 0x1) // -c
+ //if (opt & 0x2) // -f
+ //if (opt & 0x4) // -v
+ argv += optind;
+
+ SET_PTR_TO_GLOBALS((char *)xzalloc(sizeof(struct globals)+sizeof(struct globals2))
+ + sizeof(struct globals));
+
+ /* Allocate all global buffers (for DYN_ALLOC option) */
+ ALLOC(uch, G1.l_buf, INBUFSIZ);
+ ALLOC(uch, G1.outbuf, OUTBUFSIZ);
+ ALLOC(ush, G1.d_buf, DIST_BUFSIZE);
+ ALLOC(uch, G1.window, 2L * WSIZE);
+ ALLOC(ush, G1.prev, 1L << BITS);
+
+ /* Initialize the CRC32 table */
+ global_crc32_table = crc32_filltable(NULL, 0);
- write_buf(ofd, (char *) outbuf, outcnt);
- outcnt = 0;
+ return bbunpack(argv, pack_gzip, append_ext, "gz");
}
projects / platform / upstream / busybox.git / blobdiff