emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
Files
9324b400abe4365e5e50d1d4e5e155d1f708dbc0
busybox/archival/gzip.c
Erik Andersen 4d1d0113fd Reworked the source so it will compile and run under glibc 2.0.7 
and linux kernel 2.0.36 (though the dubious reasons why someone
would want to do that defy imagination ;)
 -Erik
1999-12-17 18:44:15 +00:00

3287 lines
106 KiB
C
Raw Blame History

/* gzip.c -- 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.
*
* Charles P. Wright <cpw@unix.asb.com>
*/
#include "internal.h"
#ifdef BB_GZIP
//#ifndef BB_ZCAT
//#error you need zcat to have gzip support!
//#endif
static const char gzip_usage[] =
"gzip [OPTION]... FILE\n\n"
"Compress FILE with maximum compression.\n"
"When FILE is -, reads standard input. Implies -c.\n\n"
"Options:\n"
"\t-c\tWrite output to standard output instead of FILE.gz\n";
/* gzip.h -- common declarations for all gzip modules
* Copyright (C) 1992-1993 Jean-loup Gailly.
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*/
#if defined(__STDC__) || defined(PROTO)
# define OF(args) args
#else
# define OF(args) ()
#endif
#ifdef __STDC__
typedef void *voidp;
#else
typedef char *voidp;
#endif
/* I don't like nested includes, but the string and io functions are used
* too often
*/
#include <stdio.h>
#if !defined(NO_STRING_H) || defined(STDC_HEADERS)
# include <string.h>
# if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
# include <memory.h>
# endif
# define memzero(s, n) memset ((voidp)(s), 0, (n))
#else
# include <strings.h>
# define strchr index
# define strrchr rindex
# define memcpy(d, s, n) bcopy((s), (d), (n))
# define memcmp(s1, s2, n) bcmp((s1), (s2), (n))
# define memzero(s, n) bzero((s), (n))
#endif
#ifndef RETSIGTYPE
# define RETSIGTYPE void
#endif
#define local static
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) */
#define STORED 0
#define COMPRESSED 1
#define PACKED 2
#define LZHED 3
/* methods 4 to 7 reserved */
#define DEFLATED 8
#define MAX_METHODS 9
extern int method; /* compression method */
/* To save memory for 16 bit systems, some arrays are overlaid between
* the various modules:
* deflate: prev+head window d_buf l_buf outbuf
* unlzw: tab_prefix tab_suffix stack inbuf outbuf
* inflate: window inbuf
* unpack: window inbuf prefix_len
* unlzh: left+right window c_table inbuf c_len
* For compression, input is done in window[]. For decompression, output
* is done in window except for unlzw.
*/
#ifndef INBUFSIZ
# ifdef SMALL_MEM
# define INBUFSIZ 0x2000 /* input buffer size */
# else
# define INBUFSIZ 0x8000 /* input buffer size */
# endif
#endif
#define INBUF_EXTRA 64 /* required by unlzw() */
#ifndef OUTBUFSIZ
# ifdef SMALL_MEM
# define OUTBUFSIZ 8192 /* output buffer size */
# else
# define OUTBUFSIZ 16384 /* output buffer size */
# endif
#endif
#define OUTBUF_EXTRA 2048 /* required by unlzw() */
#ifndef DIST_BUFSIZE
# ifdef SMALL_MEM
# define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
# else
# define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
# endif
#endif
#ifdef DYN_ALLOC
# define EXTERN(type, array) extern type * near array
# define DECLARE(type, array, size) type * near array
# define ALLOC(type, array, size) { \
array = (type*)fcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
if (array == NULL) error("insufficient memory"); \
}
# define FREE(array) {if (array != NULL) fcfree(array), array=NULL;}
#else
# define EXTERN(type, array) extern type array[]
# define DECLARE(type, array, size) type array[size]
# define ALLOC(type, array, size)
# define FREE(array)
#endif
EXTERN(uch, inbuf); /* input buffer */
EXTERN(uch, outbuf); /* output buffer */
EXTERN(ush, d_buf); /* buffer for distances, see trees.c */
EXTERN(uch, window); /* Sliding window and suffix table (unlzw) */
#define tab_suffix window
#ifndef MAXSEG_64K
# define tab_prefix prev /* hash link (see deflate.c) */
# define head (prev+WSIZE) /* hash head (see deflate.c) */
EXTERN(ush, tab_prefix); /* prefix code (see unlzw.c) */
#else
# define tab_prefix0 prev
# define head tab_prefix1
EXTERN(ush, tab_prefix0); /* prefix for even codes */
EXTERN(ush, tab_prefix1); /* prefix for odd codes */
#endif
extern unsigned insize; /* valid bytes in inbuf */
extern unsigned inptr; /* index of next byte to be processed in inbuf */
extern unsigned outcnt; /* bytes in output buffer */
extern long bytes_in; /* number of input bytes */
extern long bytes_out; /* number of output bytes */
extern long header_bytes;/* number of bytes in gzip header */
#define isize bytes_in
/* for compatibility with old zip sources (to be cleaned) */
extern int ifd; /* input file descriptor */
extern int ofd; /* output file descriptor */
extern char ifname[]; /* input file name or "stdin" */
extern char ofname[]; /* output file name or "stdout" */
extern char *progname; /* program name */
extern long time_stamp; /* original time stamp (modification time) */
extern long ifile_size; /* input file size, -1 for devices (debug only) */
typedef int file_t; /* Do not use stdio */
#define NO_FILE (-1) /* in memory compression */
#define PACK_MAGIC "\037\036" /* Magic header for packed files */
#define GZIP_MAGIC "\037\213" /* Magic header for gzip files, 1F 8B */
#define OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
#define LZH_MAGIC "\037\240" /* Magic header for SCO LZH Compress files*/
#define PKZIP_MAGIC "\120\113\003\004" /* Magic header for pkzip files */
/* gzip flag byte */
#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
#define COMMENT 0x10 /* bit 4 set: file comment present */
#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
#define RESERVED 0xC0 /* bit 6,7: reserved */
/* internal file attribute */
#define UNKNOWN 0xffff
#define BINARY 0
#define ASCII 1
#ifndef WSIZE
# define WSIZE 0x8000 /* window size--must be a power of two, and */
#endif /* at least 32K for zip's deflate method */
#define MIN_MATCH 3
#define MAX_MATCH 258
/* The minimum and maximum match lengths */
#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
/* Minimum amount of lookahead, except at the end of the input file.
* See deflate.c for comments about the MIN_MATCH+1.
*/
#define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
/* In order to simplify the code, particularly on 16 bit machines, match
* distances are limited to MAX_DIST instead of WSIZE.
*/
extern int decrypt; /* flag to turn on decryption */
extern int exit_code; /* program exit code */
extern int verbose; /* be verbose (-v) */
extern int quiet; /* be quiet (-q) */
extern int test; /* check .z file integrity */
extern int save_orig_name; /* set if original name must be saved */
#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
#define try_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
/* put_byte is used for the compressed output, put_ubyte for the
* uncompressed output. However unlzw() uses window for its
* suffix table instead of its output buffer, so it does not use put_ubyte
* (to be cleaned up).
*/
#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
flush_outbuf();}
#define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
flush_window();}
/* Output a 16 bit value, lsb first */
#define put_short(w) \
{ if (outcnt < OUTBUFSIZ-2) { \
outbuf[outcnt++] = (uch) ((w) & 0xff); \
outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
} else { \
put_byte((uch)((w) & 0xff)); \
put_byte((uch)((ush)(w) >> 8)); \
} \
}
/* Output a 32 bit value to the bit stream, lsb first */
#define put_long(n) { \
put_short((n) & 0xffff); \
put_short(((ulg)(n)) >> 16); \
}
#define seekable() 0 /* force sequential output */
#define translate_eol 0 /* no option -a yet */
#define tolow(c) (isupper(c) ? (c)-'A'+'a' : (c)) /* force to lower case */
/* Macros for getting two-byte and four-byte header values */
#define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
#define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
/* Diagnostic functions */
#ifdef DEBUG
# define Assert(cond,msg) {if(!(cond)) error(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;}
local void do_exit(int exitcode) __attribute__ ((noreturn));
/* in zip.c: */
extern int zip OF((int in, int out));
extern int file_read OF((char *buf, unsigned size));
/* in unzip.c */
extern int unzip OF((int in, int out));
extern int check_zipfile OF((int in));
/* in unpack.c */
extern int unpack OF((int in, int out));
/* in unlzh.c */
extern int unlzh OF((int in, int out));
/* in gzip.c */
RETSIGTYPE abort_gzip OF((void));
/* in deflate.c */
void lm_init OF((ush *flags));
ulg deflate OF((void));
/* in trees.c */
void ct_init OF((ush *attr, int *method));
int ct_tally OF((int dist, int lc));
ulg flush_block OF((char *buf, ulg stored_len, int eof));
/* in bits.c */
void bi_init OF((file_t zipfile));
void send_bits OF((int value, int length));
unsigned bi_reverse OF((unsigned value, int length));
void bi_windup OF((void));
void copy_block OF((char *buf, unsigned len, int header));
extern int (*read_buf) OF((char *buf, unsigned size));
/* in util.c: */
extern int copy OF((int in, int out));
extern ulg updcrc OF((uch *s, unsigned n));
extern void clear_bufs OF((void));
extern int fill_inbuf OF((int eof_ok));
extern void flush_outbuf OF((void));
extern void flush_window OF((void));
extern void write_buf OF((int fd, voidp buf, unsigned cnt));
extern char *strlwr OF((char *s));
extern char *add_envopt OF((int *argcp, char ***argvp, char *env));
extern void error OF((char *m));
extern void warn OF((char *a, char *b));
extern void read_error OF((void));
extern void write_error OF((void));
extern void display_ratio OF((long num, long den, FILE *file));
extern voidp xmalloc OF((unsigned int size));
/* in inflate.c */
extern int inflate OF((void));
/* lzw.h -- define the lzw functions.
* Copyright (C) 1992-1993 Jean-loup Gailly.
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*/
#if !defined(OF) && defined(lint)
# include "gzip.h"
#endif
#ifndef BITS
# define BITS 16
#endif
#define INIT_BITS 9 /* Initial number of bits per code */
#define BIT_MASK 0x1f /* Mask for 'number of compression bits' */
/* Mask 0x20 is reserved to mean a fourth header byte, and 0x40 is free.
* It's a pity that old uncompress does not check bit 0x20. That makes
* extension of the format actually undesirable because old compress
* would just crash on the new format instead of giving a meaningful
* error message. It does check the number of bits, but it's more
* helpful to say "unsupported format, get a new version" than
* "can only handle 16 bits".
*/
#define BLOCK_MODE 0x80
/* Block compression: if table is full and compression rate is dropping,
* clear the dictionary.
*/
#define LZW_RESERVED 0x60 /* reserved bits */
#define CLEAR 256 /* flush the dictionary */
#define FIRST (CLEAR+1) /* first free entry */
extern int maxbits; /* max bits per code for LZW */
extern int block_mode; /* block compress mode -C compatible with 2.0 */
/* revision.h -- define the version number
* 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 VERSION "1.2.4"
#define PATCHLEVEL 0
#define REVDATE "18 Aug 93"
/* This version does not support compression into old compress format: */
#ifdef LZW
# undef LZW
#endif
/* 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.
*/
#if defined(__MSDOS__) && !defined(MSDOS)
# define MSDOS
#endif
#if defined(__OS2__) && !defined(OS2)
# define OS2
#endif
#if defined(OS2) && defined(MSDOS) /* MS C under OS/2 */
# undef MSDOS
#endif
#ifdef MSDOS
# ifdef __GNUC__
/* DJGPP version 1.09+ on MS-DOS.
* The DJGPP 1.09 stat() function must be upgraded before gzip will
* fully work.
* No need for DIRENT, since <unistd.h> defines POSIX_SOURCE which
* implies DIRENT.
*/
# define near
# else
# define MAXSEG_64K
# ifdef __TURBOC__
# define NO_OFF_T
# ifdef __BORLANDC__
# define DIRENT
# else
# define NO_UTIME
# endif
# else /* MSC */
# define HAVE_SYS_UTIME_H
# define NO_UTIME_H
# endif
# endif
# define PATH_SEP2 '\\'
# define PATH_SEP3 ':'
# define MAX_PATH_LEN 128
# define NO_MULTIPLE_DOTS
# define MAX_EXT_CHARS 3
# define Z_SUFFIX "z"
# define NO_CHOWN
# define PROTO
# define STDC_HEADERS
# define NO_SIZE_CHECK
# define casemap(c) tolow(c) /* Force file names to lower case */
# include <io.h>
# define OS_CODE 0x00
# define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
# if !defined(NO_ASM) && !defined(ASMV)
# define ASMV
# endif
#else
# define near
#endif
#ifdef OS2
# define PATH_SEP2 '\\'
# define PATH_SEP3 ':'
# define MAX_PATH_LEN 260
# ifdef OS2FAT
# define NO_MULTIPLE_DOTS
# define MAX_EXT_CHARS 3
# define Z_SUFFIX "z"
# define casemap(c) tolow(c)
# endif
# define NO_CHOWN
# define PROTO
# define STDC_HEADERS
# include <io.h>
# define OS_CODE 0x06
# define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
# ifdef _MSC_VER
# define HAVE_SYS_UTIME_H
# define NO_UTIME_H
# define MAXSEG_64K
# undef near
# define near _near
# endif
# ifdef __EMX__
# define HAVE_SYS_UTIME_H
# define NO_UTIME_H
# define DIRENT
# define EXPAND(argc,argv) \
{_response(&argc, &argv); _wildcard(&argc, &argv);}
# endif
# ifdef __BORLANDC__
# define DIRENT
# endif
# ifdef __ZTC__
# define NO_DIR
# define NO_UTIME_H
# include <dos.h>
# define EXPAND(argc,argv) \
{response_expand(&argc, &argv);}
# endif
#endif
#ifdef WIN32 /* Windows NT */
# define HAVE_SYS_UTIME_H
# define NO_UTIME_H
# define PATH_SEP2 '\\'
# define PATH_SEP3 ':'
# define MAX_PATH_LEN 260
# define NO_CHOWN
# define PROTO
# define STDC_HEADERS
# define SET_BINARY_MODE(fd) setmode(fd, O_BINARY)
# include <io.h>
# include <malloc.h>
# ifdef NTFAT
# define NO_MULTIPLE_DOTS
# define MAX_EXT_CHARS 3
# define Z_SUFFIX "z"
# define casemap(c) tolow(c) /* Force file names to lower case */
# endif
# define OS_CODE 0x0b
#endif
#ifdef MSDOS
# ifdef __TURBOC__
# include <alloc.h>
# define DYN_ALLOC
/* Turbo C 2.0 does not accept static allocations of large arrays */
void * fcalloc (unsigned items, unsigned size);
void fcfree (void *ptr);
# else /* MSC */
# include <malloc.h>
# define fcalloc(nitems,itemsize) halloc((long)(nitems),(itemsize))
# define fcfree(ptr) hfree(ptr)
# endif
#else
# ifdef MAXSEG_64K
# define fcalloc(items,size) calloc((items),(size))
# else
# define fcalloc(items,size) malloc((size_t)(items)*(size_t)(size))
# endif
# define fcfree(ptr) free(ptr)
#endif
#if defined(VAXC) || defined(VMS)
# define PATH_SEP ']'
# define PATH_SEP2 ':'
# define SUFFIX_SEP ';'
# define NO_MULTIPLE_DOTS
# define Z_SUFFIX "-gz"
# define RECORD_IO 1
# define casemap(c) tolow(c)
# define OS_CODE 0x02
# define OPTIONS_VAR "GZIP_OPT"
# define STDC_HEADERS
# define NO_UTIME
# define EXPAND(argc,argv) vms_expand_args(&argc,&argv);
# include <file.h>
# define unlink delete
# ifdef VAXC
# define NO_FCNTL_H
# include <unixio.h>
# endif
#endif
#ifdef AMIGA
# define PATH_SEP2 ':'
# define STDC_HEADERS
# define OS_CODE 0x01
# define ASMV
# ifdef __GNUC__
# define DIRENT
# define HAVE_UNISTD_H
# else /* SASC */
# define NO_STDIN_FSTAT
# define SYSDIR
# define NO_SYMLINK
# define NO_CHOWN
# define NO_FCNTL_H
# include <fcntl.h> /* for read() and write() */
# define direct dirent
extern void _expand_args(int *argc, char ***argv);
# define EXPAND(argc,argv) _expand_args(&argc,&argv);
# undef O_BINARY /* disable useless --ascii option */
# endif
#endif
#if defined(ATARI) || defined(atarist)
# ifndef STDC_HEADERS
# define STDC_HEADERS
# define HAVE_UNISTD_H
# define DIRENT
# endif
# define ASMV
# define OS_CODE 0x05
# ifdef TOSFS
# define PATH_SEP2 '\\'
# define PATH_SEP3 ':'
# define MAX_PATH_LEN 128
# define NO_MULTIPLE_DOTS
# define MAX_EXT_CHARS 3
# define Z_SUFFIX "z"
# define NO_CHOWN
# define casemap(c) tolow(c) /* Force file names to lower case */
# define NO_SYMLINK
# endif
#endif
#ifdef MACOS
# define PATH_SEP ':'
# define DYN_ALLOC
# define PROTO
# define NO_STDIN_FSTAT
# define NO_CHOWN
# define NO_UTIME
# define chmod(file, mode) (0)
# define OPEN(name, flags, mode) open(name, flags)
# define OS_CODE 0x07
# ifdef MPW
# define isatty(fd) ((fd) <= 2)
# endif
#endif
#ifdef __50SERIES /* Prime/PRIMOS */
# define PATH_SEP '>'
# define STDC_HEADERS
# define NO_MEMORY_H
# define NO_UTIME_H
# define NO_UTIME
# define NO_CHOWN
# define NO_STDIN_FSTAT
# define NO_SIZE_CHECK
# define NO_SYMLINK
# define RECORD_IO 1
# define casemap(c) tolow(c) /* Force file names to lower case */
# define put_char(c) put_byte((c) & 0x7F)
# define get_char(c) ascii2pascii(get_byte())
# define OS_CODE 0x0F /* temporary, subject to change */
# ifdef SIGTERM
# undef SIGTERM /* We don't want a signal handler for SIGTERM */
# endif
#endif
#if defined(pyr) && !defined(NOMEMCPY) /* Pyramid */
# define NOMEMCPY /* problem with overlapping copies */
#endif
#ifdef TOPS20
# define OS_CODE 0x0a
#endif
#ifndef unix
# define NO_ST_INO /* don't rely on inode numbers */
#endif
/* Common defaults */
#ifndef OS_CODE
# define OS_CODE 0x03 /* assume Unix */
#endif
#ifndef PATH_SEP
# define PATH_SEP '/'
#endif
#ifndef casemap
# define casemap(c) (c)
#endif
#ifndef OPTIONS_VAR
# define OPTIONS_VAR "GZIP"
#endif
#ifndef Z_SUFFIX
# define Z_SUFFIX ".gz"
#endif
#ifdef MAX_EXT_CHARS
# define MAX_SUFFIX MAX_EXT_CHARS
#else
# define MAX_SUFFIX 30
#endif
#ifndef MAKE_LEGAL_NAME
# ifdef NO_MULTIPLE_DOTS
# define MAKE_LEGAL_NAME(name) make_simple_name(name)
# else
# define MAKE_LEGAL_NAME(name)
# endif
#endif
#ifndef MIN_PART
# define MIN_PART 3
/* keep at least MIN_PART chars between dots in a file name. */
#endif
#ifndef EXPAND
# define EXPAND(argc,argv)
#endif
#ifndef RECORD_IO
# define RECORD_IO 0
#endif
#ifndef SET_BINARY_MODE
# define SET_BINARY_MODE(fd)
#endif
#ifndef OPEN
# define OPEN(name, flags, mode) open(name, flags, mode)
#endif
#ifndef get_char
# define get_char() get_byte()
#endif
#ifndef put_char
# define put_char(c) put_byte(c)
#endif
/* bits.c -- output variable-length bit strings
* Copyright (C) 1992-1993 Jean-loup Gailly
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*/
/*
* PURPOSE
*
* Output variable-length bit strings. Compression can be done
* to a file or to memory. (The latter is not supported in this version.)
*
* DISCUSSION
*
* The PKZIP "deflate" file format interprets compressed file data
* as a sequence of bits. Multi-bit strings in the file may cross
* byte boundaries without restriction.
*
* The first bit of each byte is the low-order bit.
*
* The routines in this file allow a variable-length bit value to
* be output right-to-left (useful for literal values). For
* left-to-right output (useful for code strings from the tree routines),
* the bits must have been reversed first with bi_reverse().
*
* For in-memory compression, the compressed bit stream goes directly
* into the requested output buffer. The input data is read in blocks
* by the mem_read() function. The buffer is limited to 64K on 16 bit
* machines.
*
* INTERFACE
*
* void bi_init (FILE *zipfile)
* Initialize the bit string routines.
*
* void send_bits (int value, int length)
* Write out a bit string, taking the source bits right to
* left.
*
* int bi_reverse (int value, int length)
* Reverse the bits of a bit string, taking the source bits left to
* right and emitting them right to left.
*
* void bi_windup (void)
* Write out any remaining bits in an incomplete byte.
*
* void copy_block(char *buf, unsigned len, int header)
* Copy a stored block to the zip file, storing first the length and
* its one's complement if requested.
*
*/
#ifdef DEBUG
# include <stdio.h>
#endif
/* ===========================================================================
* Local data used by the "bit string" routines.
*/
local file_t zfile; /* output gzip file */
local unsigned short bi_buf;
/* Output buffer. bits are inserted starting at the bottom (least significant
* bits).
*/
#define Buf_size (8 * 2*sizeof(char))
/* Number of bits used within bi_buf. (bi_buf might be implemented on
* more than 16 bits on some systems.)
*/
local int bi_valid;
/* Number of valid bits in bi_buf. All bits above the last valid bit
* are always zero.
*/
int (*read_buf) OF((char *buf, unsigned size));
/* Current input function. Set to mem_read for in-memory compression */
#ifdef DEBUG
ulg bits_sent; /* bit length of the compressed data */
#endif
/* ===========================================================================
* Initialize the bit string routines.
*/
void bi_init (zipfile)
file_t zipfile; /* output zip file, NO_FILE for in-memory compression */
{
zfile = zipfile;
bi_buf = 0;
bi_valid = 0;
#ifdef DEBUG
bits_sent = 0L;
#endif
/* Set the defaults for file compression. They are set by memcompress
* for in-memory compression.
*/
if (zfile != NO_FILE) {
read_buf = file_read;
}
}
/* ===========================================================================
* Send a value on a given number of bits.
* IN assertion: length <= 16 and value fits in length bits.
*/
void send_bits(value, length)
int value; /* value to send */
int length; /* number of bits */
{
#ifdef DEBUG
Tracev((stderr," l %2d v %4x ", length, value));
Assert(length > 0 && length <= 15, "invalid length");
bits_sent += (ulg)length;
#endif
/* If not enough room in bi_buf, use (valid) bits from bi_buf and
* (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
* unused bits in value.
*/
if (bi_valid > (int)Buf_size - length) {
bi_buf |= (value << bi_valid);
put_short(bi_buf);
bi_buf = (ush)value >> (Buf_size - bi_valid);
bi_valid += length - Buf_size;
} else {
bi_buf |= value << bi_valid;
bi_valid += length;
}
}
/* ===========================================================================
* Reverse the first len bits of a code, using straightforward code (a faster
* method would use a table)
* IN assertion: 1 <= len <= 15
*/
unsigned bi_reverse(code, len)
unsigned code; /* the value to invert */
int len; /* its bit length */
{
register unsigned res = 0;
do {
res |= code & 1;
code >>= 1, res <<= 1;
} while (--len > 0);
return res >> 1;
}
/* ===========================================================================
* Write out any remaining bits in an incomplete byte.
*/
void bi_windup()
{
if (bi_valid > 8) {
put_short(bi_buf);
} else if (bi_valid > 0) {
put_byte(bi_buf);
}
bi_buf = 0;
bi_valid = 0;
#ifdef DEBUG
bits_sent = (bits_sent+7) & ~7;
#endif
}
/* ===========================================================================
* Copy a stored block to the zip file, storing first the length and its
* one's complement if requested.
*/
void copy_block(buf, len, header)
char *buf; /* the input data */
unsigned len; /* its length */
int header; /* true if block header must be written */
{
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--) {
#ifdef CRYPT
int t;
if (key) zencode(*buf, t);
#endif
put_byte(*buf++);
}
}
/* deflate.c -- compress data using the deflation algorithm
* Copyright (C) 1992-1993 Jean-loup Gailly
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*/
/*
* PURPOSE
*
* Identify new text as repetitions of old text within a fixed-
* length sliding window trailing behind the new text.
*
* DISCUSSION
*
* The "deflation" process depends on being able to identify portions
* of the input text which are identical to earlier input (within a
* sliding window trailing behind the input currently being processed).
*
* The most straightforward technique turns out to be the fastest for
* most input files: try all possible matches and select the longest.
* The key feature of this algorithm is that insertions into the string
* dictionary are very simple and thus fast, and deletions are avoided
* completely. Insertions are performed at each input character, whereas
* string matches are performed only when the previous match ends. So it
* is preferable to spend more time in matches to allow very fast string
* insertions and avoid deletions. The matching algorithm for small
* strings is inspired from that of Rabin & Karp. A brute force approach
* is used to find longer strings when a small match has been found.
* A similar algorithm is used in comic (by Jan-Mark Wams) and freeze
* (by Leonid Broukhis).
* A previous version of this file used a more sophisticated algorithm
* (by Fiala and Greene) which is guaranteed to run in linear amortized
* time, but has a larger average cost, uses more memory and is patented.
* However the F&G algorithm may be faster for some highly redundant
* files if the parameter max_chain_length (described below) is too large.
*
* ACKNOWLEDGEMENTS
*
* The idea of lazy evaluation of matches is due to Jan-Mark Wams, and
* I found it in 'freeze' written by Leonid Broukhis.
* Thanks to many info-zippers for bug reports and testing.
*
* REFERENCES
*
* APPNOTE.TXT documentation file in PKZIP 1.93a distribution.
*
* A description of the Rabin and Karp algorithm is given in the book
* "Algorithms" by R. Sedgewick, Addison-Wesley, p252.
*
* Fiala,E.R., and Greene,D.H.
* Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595
*
* INTERFACE
*
* void lm_init (int pack_level, ush *flags)
* Initialize the "longest match" routines for a new file
*
* ulg deflate (void)
* Processes a new input file and return its compressed length. Sets
* the compressed length, crc, deflate flags and internal file
* attributes.
*/
#include <stdio.h>
/* ===========================================================================
* 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. */
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.
*/
long block_start;
/* window position at the beginning of the current output block. Gets
* negative when the window is moved backwards.
*/
local 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
*/
unsigned int near 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.
*/
unsigned near strstart; /* start of string to insert */
unsigned near match_start; /* start of matching string */
local int eofile; /* flag set at end of input file */
local unsigned lookahead; /* number of valid bytes ahead in window */
unsigned near max_chain_length;
/* To speed up deflation, hash chains are never searched beyond this length.
* A higher limit improves compression ratio but degrades the speed.
*/
local unsigned int max_lazy_match;
/* Attempt to find a better match only when the current match is strictly
* smaller than this value. This mechanism is used only for compression
* levels >= 4.
*/
#define max_insert_length max_lazy_match
/* Insert new strings in the hash table only if the match length
* is not greater than this length. This saves time but degrades compression.
* max_insert_length is used only for compression levels <= 3.
*/
unsigned near good_match;
/* Use a faster search when the previous match is longer than this */
/* Values for max_lazy_match, good_match and max_chain_length, depending on
* the desired pack level (0..9). The values given below have been tuned to
* exclude worst case performance for pathological files. Better values may be
* found for specific files.
*/
typedef struct config {
ush good_length; /* reduce lazy search above this match length */
ush max_lazy; /* do not perform lazy search above this match length */
ush nice_length; /* quit search above this match length */
ush max_chain;
} config;
#ifdef FULL_SEARCH
# define nice_match MAX_MATCH
#else
int near nice_match; /* Stop searching when current match exceeds this */
#endif
local config configuration_table =
/* 9 */ {32, 258, 258, 4096}; /* maximum compression */
/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4
* For deflate_fast() (levels <= 3) good is ignored and lazy has a different
* meaning.
*/
#define EQUAL 0
/* result of memcmp for equal strings */
/* ===========================================================================
* Prototypes for local functions.
*/
local void fill_window OF((void));
int longest_match OF((IPos cur_match));
#ifdef ASMV
void match_init OF((void)); /* asm code initialization */
#endif
#ifdef DEBUG
local void check_match OF((IPos start, IPos match, int length));
#endif
/* ===========================================================================
* Update a hash value with the given input byte
* IN assertion: all calls to to UPDATE_HASH are made with consecutive
* input characters, so that a running hash key can be computed from the
* previous key instead of complete recalculation each time.
*/
#define UPDATE_HASH(h,c) (h = (((h)<<H_SHIFT) ^ (c)) & HASH_MASK)
/* ===========================================================================
* Insert string s in the dictionary and set match_head to the previous head
* of the hash chain (the most recent string with same hash key). Return
* the previous length of the hash chain.
* IN assertion: all calls to to INSERT_STRING are made with consecutive
* input characters and the first MIN_MATCH bytes of s are valid
* (except for the last MIN_MATCH-1 bytes of the input file).
*/
#define INSERT_STRING(s, match_head) \
(UPDATE_HASH(ins_h, window[(s) + MIN_MATCH-1]), \
prev[(s) & WMASK] = match_head = head[ins_h], \
head[ins_h] = (s))
/* ===========================================================================
* Initialize the "longest match" routines for a new file
*/
void lm_init (flags)
ush *flags; /* general purpose bit flag */
{
register unsigned j;
/* Initialize the hash table. */
#if defined(MAXSEG_64K) && HASH_BITS == 15
for (j = 0; j < HASH_SIZE; j++) head[j] = NIL;
#else
memzero((char*)head, HASH_SIZE*sizeof(*head));
#endif
/* prev will be initialized on the fly */
/* Set the default configuration parameters:
*/
max_lazy_match = configuration_table.max_lazy;
good_match = configuration_table.good_length;
#ifndef FULL_SEARCH
nice_match = configuration_table.nice_length;
#endif
max_chain_length = configuration_table.max_chain;
*flags |= SLOW;
/* ??? reduce max_chain_length for binary files */
strstart = 0;
block_start = 0L;
#ifdef ASMV
match_init(); /* initialize the asm code */
#endif
lookahead = read_buf((char*)window,
sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
if (lookahead == 0 || lookahead == (unsigned)EOF) {
eofile = 1, lookahead = 0;
return;
}
eofile = 0;
/* Make sure that we always have enough lookahead. This is important
* if input comes from a device such as a tty.
*/
while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
ins_h = 0;
for (j=0; j<MIN_MATCH-1; j++) UPDATE_HASH(ins_h, window[j]);
/* If lookahead < MIN_MATCH, ins_h is garbage, but this is
* not important since only literal bytes will be emitted.
*/
}
/* ===========================================================================
* Set match_start to the longest match starting at the given string and
* return its length. Matches shorter or equal to prev_length are discarded,
* in which case the result is equal to prev_length and match_start is
* garbage.
* IN assertions: cur_match is the head of the hash chain for the current
* string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1
*/
#ifndef ASMV
/* 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.
*/
int longest_match(cur_match)
IPos cur_match; /* current match */
{
unsigned chain_length = max_chain_length; /* max hash chain length */
register uch *scan = window + strstart; /* current string */
register uch *match; /* matched string */
register int len; /* length of current match */
int best_len = prev_length; /* best match length so far */
IPos limit = strstart > (IPos)MAX_DIST ? strstart - (IPos)MAX_DIST : NIL;
/* Stop when cur_match becomes <= limit. To simplify the code,
* we prevent matches with the string of window index 0.
*/
/* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16.
* It is easy to get rid of this optimization if necessary.
*/
#if HASH_BITS < 8 || MAX_MATCH != 258
error: Code too clever
#endif
#ifdef UNALIGNED_OK
/* Compare two bytes at a time. Note: this is not always beneficial.
* Try with and without -DUNALIGNED_OK to check.
*/
register uch *strend = window + strstart + MAX_MATCH - 1;
register ush scan_start = *(ush*)scan;
register ush scan_end = *(ush*)(scan+best_len-1);
#else
register uch *strend = window + strstart + MAX_MATCH;
register uch scan_end1 = scan[best_len-1];
register uch scan_end = scan[best_len];
#endif
/* Do not waste too much time if we already have a good match: */
if (prev_length >= good_match) {
chain_length >>= 2;
}
Assert(strstart <= window_size-MIN_LOOKAHEAD, "insufficient lookahead");
do {
Assert(cur_match < strstart, "no future");
match = window + cur_match;
/* Skip to next match if the match length cannot increase
* or if the match length is less than 2:
*/
#if (defined(UNALIGNED_OK) && MAX_MATCH == 258)
/* This code assumes sizeof(unsigned short) == 2. Do not use
* UNALIGNED_OK if your compiler uses a different size.
*/
if (*(ush*)(match+best_len-1) != scan_end ||
*(ush*)match != scan_start) continue;
/* 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. Compare 2 bytes at a time at
* strstart+3, +5, ... up to strstart+257. We check for insufficient
* lookahead only every 4th comparison; the 128th check will be made
* at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is
* necessary to put more guard bytes at the end of the window, or
* to check more often for insufficient lookahead.
*/
scan++, match++;
do {
} while (*(ush*)(scan+=2) == *(ush*)(match+=2) &&
*(ush*)(scan+=2) == *(ush*)(match+=2) &&
*(ush*)(scan+=2) == *(ush*)(match+=2) &&
*(ush*)(scan+=2) == *(ush*)(match+=2) &&
scan < strend);
/* The funny "do {}" generates better code on most compilers */
/* Here, scan <= window+strstart+257 */
Assert(scan <= window+(unsigned)(window_size-1), "wild scan");
if (*scan == *match) scan++;
len = (MAX_MATCH - 1) - (int)(strend-scan);
scan = strend - (MAX_MATCH-1);
#else /* UNALIGNED_OK */
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;
#endif /* UNALIGNED_OK */
if (len > best_len) {
match_start = cur_match;
best_len = len;
if (len >= nice_match) break;
#ifdef UNALIGNED_OK
scan_end = *(ush*)(scan+best_len-1);
#else
scan_end1 = scan[best_len-1];
scan_end = scan[best_len];
#endif
}
} while ((cur_match = prev[cur_match & WMASK]) > limit
&& --chain_length != 0);
return best_len;
}
#endif /* ASMV */
#ifdef DEBUG
/* ===========================================================================
* Check that the match at match_start is indeed a match.
*/
local void check_match(start, match, length)
IPos start, match;
int length;
{
/* check that the match is indeed a match */
if (memcmp((char*)window + match,
(char*)window + start, length) != EQUAL) {
fprintf(stderr,
" start %d, match %d, length %d\n",
start, match, length);
error("invalid match");
}
if (verbose > 1) {
fprintf(stderr,"\\[%d,%d]", start-match, length);
do { putc(window[start++], stderr); } while (--length != 0);
}
}
#else
# define check_match(start, match, length)
#endif
/* ===========================================================================
* Fill the window when the lookahead becomes insufficient.
* Updates strstart and lookahead, and sets eofile if end of input file.
* IN assertion: lookahead < MIN_LOOKAHEAD && strstart + lookahead > 0
* OUT assertions: at least one byte has been read, or eofile is set;
* file reads are performed for at least two bytes (required for the
* translate_eol option).
*/
local void fill_window()
{
register unsigned n, m;
unsigned more = (unsigned)(window_size - (ulg)lookahead - (ulg)strstart);
/* Amount of free space at the end of the window. */
/* If the window is almost full and there is insufficient lookahead,
* move the upper half to the lower one to make room in the upper half.
*/
if (more == (unsigned)EOF) {
/* Very unlikely, but possible on 16 bit machine if strstart == 0
* and lookahead == 1 (input done one byte at time)
*/
more--;
} else if (strstart >= WSIZE+MAX_DIST) {
/* By the IN assertion, the window is not empty so we can't confuse
* more == 0 with more == 64K on a 16 bit machine.
*/
Assert(window_size == (ulg)2*WSIZE, "no sliding with BIG_MEM");
memcpy((char*)window, (char*)window+WSIZE, (unsigned)WSIZE);
match_start -= WSIZE;
strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */
block_start -= (long) WSIZE;
for (n = 0; n < HASH_SIZE; n++) {
m = head[n];
head[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
}
for (n = 0; n < WSIZE; n++) {
m = prev[n];
prev[n] = (Pos)(m >= WSIZE ? m-WSIZE : NIL);
/* If n is not on any hash chain, prev[n] is garbage but
* its value will never be used.
*/
}
more += WSIZE;
}
/* At this point, more >= 2 */
if (!eofile) {
n = read_buf((char*)window+strstart+lookahead, more);
if (n == 0 || n == (unsigned)EOF) {
eofile = 1;
} else {
lookahead += n;
}
}
}
/* ===========================================================================
* Flush the current block, with given end-of-file flag.
* IN assertion: strstart is set to the end of the current match.
*/
#define FLUSH_BLOCK(eof) \
flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \
(char*)NULL, (long)strstart - block_start, (eof))
/* ===========================================================================
* Same as above, but achieves better compression. We use a lazy
* evaluation for matches: a match is finally adopted only if there is
* no better match at the next window position.
*/
ulg deflate()
{
IPos hash_head; /* head of hash chain */
IPos prev_match; /* previous match */
int flush; /* set if current block must be flushed */
int match_available = 0; /* set if previous match exists */
register unsigned match_length = MIN_MATCH-1; /* length of best match */
#ifdef DEBUG
extern long isize; /* byte length of input file, for debug only */
#endif
/* Process the input block. */
while (lookahead != 0) {
/* Insert the string window[strstart .. strstart+2] in the
* dictionary, and set hash_head to the head of the hash chain:
*/
INSERT_STRING(strstart, hash_head);
/* Find the longest match, discarding those <= prev_length.
*/
prev_length = match_length, prev_match = match_start;
match_length = MIN_MATCH-1;
if (hash_head != NIL && prev_length < max_lazy_match &&
strstart - hash_head <= MAX_DIST) {
/* To simplify the code, we prevent matches with the string
* of window index 0 (in particular we have to avoid a match
* of the string with itself at the start of the input file).
*/
match_length = longest_match (hash_head);
/* longest_match() sets match_start */
if (match_length > lookahead) match_length = lookahead;
/* Ignore a length 3 match if it is too distant: */
if (match_length == MIN_MATCH && strstart-match_start > TOO_FAR){
/* If prev_match is also MIN_MATCH, match_start is garbage
* but we will ignore the current match anyway.
*/
match_length--;
}
}
/* If there was a match at the previous step and the current
* match is not better, output the previous match:
*/
if (prev_length >= MIN_MATCH && match_length <= prev_length) {
check_match(strstart-1, prev_match, prev_length);
flush = ct_tally(strstart-1-prev_match, prev_length - MIN_MATCH);
/* Insert in hash table all strings up to the end of the match.
* strstart-1 and strstart are already inserted.
*/
lookahead -= prev_length-1;
prev_length -= 2;
do {
strstart++;
INSERT_STRING(strstart, hash_head);
/* strstart never exceeds WSIZE-MAX_MATCH, so there are
* always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH
* these bytes are garbage, but it does not matter since the
* next lookahead bytes will always be emitted as literals.
*/
} while (--prev_length != 0);
match_available = 0;
match_length = MIN_MATCH-1;
strstart++;
if (flush) FLUSH_BLOCK(0), block_start = strstart;
} else if (match_available) {
/* If there was no match at the previous position, output a
* single literal. If there was a match but the current match
* is longer, truncate the previous match to a single literal.
*/
Tracevv((stderr,"%c",window[strstart-1]));
if (ct_tally (0, window[strstart-1])) {
FLUSH_BLOCK(0), block_start = strstart;
}
strstart++;
lookahead--;
} else {
/* There is no previous match to compare with, wait for
* the next step to decide.
*/
match_available = 1;
strstart++;
lookahead--;
}
Assert (strstart <= isize && lookahead <= isize, "a bit too far");
/* Make sure that we always have enough lookahead, except
* at the end of the input file. We need MAX_MATCH bytes
* for the next match, plus MIN_MATCH bytes to insert the
* string following the next match.
*/
while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
}
if (match_available) ct_tally (0, window[strstart-1]);
return FLUSH_BLOCK(1); /* eof */
}
/* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
* Copyright (C) 1992-1993 Jean-loup Gailly
* The unzip code was written and put in the public domain by Mark Adler.
* Portions of the lzw code are derived from the public domain 'compress'
* written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
* Ken Turkowski, Dave Mack and Peter Jannesen.
*
* See the license_msg below and the file COPYING for the software license.
* See the file algorithm.doc for the compression algorithms and file formats.
*/
/* Compress files with zip algorithm and 'compress' interface.
* See usage() and help() functions below for all options.
* Outputs:
* file.gz: compressed file with same mode, owner, and utimes
* or stdout with -c option or if stdin used as input.
* If the output file name had to be truncated, the original name is kept
* in the compressed file.
* On MSDOS, file.tmp -> file.tmz. On VMS, file.tmp -> file.tmp-gz.
*
* Using gz on MSDOS would create too many file name conflicts. For
* example, foo.txt -> foo.tgz (.tgz must be reserved as shorthand for
* tar.gz). Similarly, foo.dir and foo.doc would both be mapped to foo.dgz.
* I also considered 12345678.txt -> 12345txt.gz but this truncates the name
* too heavily. There is no ideal solution given the MSDOS 8+3 limitation.
*
* For the meaning of all compilation flags, see comments in Makefile.in.
*/
#include <ctype.h>
#include <sys/types.h>
#include <signal.h>
#include <sys/stat.h>
#include <errno.h>
/* configuration */
#ifdef NO_TIME_H
# include <sys/time.h>
#else
# include <time.h>
#endif
#ifndef NO_FCNTL_H
# include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
# include <stdlib.h>
#else
extern int errno;
#endif
#if defined(DIRENT)
# include <dirent.h>
typedef struct dirent dir_type;
# define NLENGTH(dirent) ((int)strlen((dirent)->d_name))
# define DIR_OPT "DIRENT"
#else
# define NLENGTH(dirent) ((dirent)->d_namlen)
# ifdef SYSDIR
# include <sys/dir.h>
typedef struct direct dir_type;
# define DIR_OPT "SYSDIR"
# else
# ifdef SYSNDIR
# include <sys/ndir.h>
typedef struct direct dir_type;
# define DIR_OPT "SYSNDIR"
# else
# ifdef NDIR
# include <ndir.h>
typedef struct direct dir_type;
# define DIR_OPT "NDIR"
# else
# define NO_DIR
# define DIR_OPT "NO_DIR"
# endif
# endif
# endif
#endif
#ifndef NO_UTIME
# ifndef NO_UTIME_H
# include <utime.h>
# define TIME_OPT "UTIME"
# else
# ifdef HAVE_SYS_UTIME_H
# include <sys/utime.h>
# define TIME_OPT "SYS_UTIME"
# else
struct utimbuf {
time_t actime;
time_t modtime;
};
# define TIME_OPT ""
# endif
# endif
#else
# define TIME_OPT "NO_UTIME"
#endif
#if !defined(S_ISDIR) && defined(S_IFDIR)
# define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
#if !defined(S_ISREG) && defined(S_IFREG)
# define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
#endif
typedef RETSIGTYPE (*sig_type) OF((int));
#ifndef O_BINARY
# define O_BINARY 0 /* creation mode for open() */
#endif
#ifndef O_CREAT
/* Pure BSD system? */
# include <sys/file.h>
# ifndef O_CREAT
# define O_CREAT FCREAT
# endif
# ifndef O_EXCL
# define O_EXCL FEXCL
# endif
#endif
#ifndef S_IRUSR
# define S_IRUSR 0400
#endif
#ifndef S_IWUSR
# define S_IWUSR 0200
#endif
#define RW_USER (S_IRUSR | S_IWUSR) /* creation mode for open() */
#ifndef MAX_PATH_LEN
# define MAX_PATH_LEN 1024 /* max pathname length */
#endif
#ifndef SEEK_END
# define SEEK_END 2
#endif
#ifdef NO_OFF_T
typedef long off_t;
off_t lseek OF((int fd, off_t offset, int whence));
#endif
/* Separator for file name parts (see shorten_name()) */
#ifdef NO_MULTIPLE_DOTS
# define PART_SEP "-"
#else
# define PART_SEP "."
#endif
/* global buffers */
DECLARE(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
DECLARE(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
DECLARE(ush, d_buf, DIST_BUFSIZE);
DECLARE(uch, window, 2L*WSIZE);
#ifndef MAXSEG_64K
DECLARE(ush, tab_prefix, 1L<<BITS);
#else
DECLARE(ush, tab_prefix0, 1L<<(BITS-1));
DECLARE(ush, tab_prefix1, 1L<<(BITS-1));
#endif
/* local variables */
int ascii = 0; /* convert end-of-lines to local OS conventions */
int decompress = 0; /* decompress (-d) */
int no_name = -1; /* don't save or restore the original file name */
int no_time = -1; /* don't save or restore the original file time */
int foreground; /* set if program run in foreground */
char *progname; /* program name */
static int method = DEFLATED;/* compression method */
static int exit_code = OK; /* program exit code */
int save_orig_name; /* set if original name must be saved */
int last_member; /* set for .zip and .Z files */
int part_nb; /* number of parts in .gz file */
long time_stamp; /* original time stamp (modification time) */
long ifile_size; /* input file size, -1 for devices (debug only) */
char *env; /* contents of GZIP env variable */
char **args = NULL; /* argv pointer if GZIP env variable defined */
char z_suffix[MAX_SUFFIX+1]; /* default suffix (can be set with --suffix) */
int z_len; /* strlen(z_suffix) */
long bytes_in; /* number of input bytes */
long bytes_out; /* number of output bytes */
char ifname[MAX_PATH_LEN]; /* input file name */
char ofname[MAX_PATH_LEN]; /* output file name */
int remove_ofname = 0; /* remove output file on error */
struct stat istat; /* status for input file */
int ifd; /* input file descriptor */
int ofd; /* output file descriptor */
unsigned insize; /* valid bytes in inbuf */
unsigned inptr; /* index of next byte to be processed in inbuf */
unsigned outcnt; /* bytes in output buffer */
/* local functions */
#define strequ(s1, s2) (strcmp((s1),(s2)) == 0)
/* ======================================================================== */
// int main (argc, argv)
// int argc;
// char **argv;
int gzip_main(int argc, char ** argv)
{
int result;
int inFileNum;
int outFileNum;
struct stat statBuf;
char* delFileName;
int tostdout = 0;
int fromstdin = 0;
if (argc==1)
usage(gzip_usage);
/* Parse any options */
while (--argc > 0 && **(++argv) == '-') {
if (*((*argv)+1) == '\0') {
fromstdin = 1;
tostdout = 1;
}
while (*(++(*argv))) {
switch (**argv) {
case 'c':
tostdout = 1;
break;
default:
usage(gzip_usage);
}
}
}
foreground = signal(SIGINT, SIG_IGN) != SIG_IGN;
if (foreground) {
(void) signal (SIGINT, (sig_type)abort_gzip);
}
#ifdef SIGTERM
if (signal(SIGTERM, SIG_IGN) != SIG_IGN) {
(void) signal(SIGTERM, (sig_type)abort_gzip);
}
#endif
#ifdef SIGHUP
if (signal(SIGHUP, SIG_IGN) != SIG_IGN) {
(void) signal(SIGHUP, (sig_type)abort_gzip);
}
#endif
strncpy(z_suffix, Z_SUFFIX, sizeof(z_suffix)-1);
z_len = strlen(z_suffix);
/* Allocate all global buffers (for DYN_ALLOC option) */
ALLOC(uch, inbuf, INBUFSIZ +INBUF_EXTRA);
ALLOC(uch, outbuf, OUTBUFSIZ+OUTBUF_EXTRA);
ALLOC(ush, d_buf, DIST_BUFSIZE);
ALLOC(uch, window, 2L*WSIZE);
#ifndef MAXSEG_64K
ALLOC(ush, tab_prefix, 1L<<BITS);
#else
ALLOC(ush, tab_prefix0, 1L<<(BITS-1));
ALLOC(ush, tab_prefix1, 1L<<(BITS-1));
#endif
if (fromstdin==1) {
strcpy(ofname, "stdin");
inFileNum=fileno(stdin);
time_stamp = 0; /* time unknown by default */
ifile_size = -1L; /* convention for unknown size */
} else {
/* Open up the input file */
if (*argv=='\0')
usage(gzip_usage);
strncpy(ifname, *argv, MAX_PATH_LEN);
/* Open input fille */
inFileNum=open( ifname, O_RDONLY);
if (inFileNum < 0) {
perror(ifname);
do_exit(WARNING);
}
/* Get the time stamp on the input file. */
result = stat(ifname, &statBuf);
if (result < 0) {
perror(ifname);
do_exit(WARNING);
}
time_stamp = statBuf.st_ctime;
ifile_size = statBuf.st_size;
}
if (tostdout==1) {
/* And get to work */
strcpy(ofname, "stdout");
outFileNum=fileno(stdout);
SET_BINARY_MODE(fileno(stdout));
clear_bufs(); /* clear input and output buffers */
part_nb = 0;
/* Actually do the compression/decompression. */
zip(inFileNum, outFileNum);
} else {
/* And get to work */
strncpy(ofname, ifname, MAX_PATH_LEN-4);
strcat(ofname, ".gz");
/* Open output fille */
#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
outFileNum=open( ofname, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW);
#else
outFileNum=open( ofname, O_RDWR|O_CREAT|O_EXCL);
#endif
if (outFileNum < 0) {
perror(ofname);
do_exit(WARNING);
}
SET_BINARY_MODE(outFileNum);
/* Set permissions on the file */
fchmod(outFileNum, statBuf.st_mode);
clear_bufs(); /* clear input and output buffers */
part_nb = 0;
/* Actually do the compression/decompression. */
result=zip(inFileNum, outFileNum);
close( outFileNum);
close( inFileNum);
/* Delete the original file */
if (result == OK)
delFileName=ifname;
else
delFileName=ofname;
if (unlink (delFileName) < 0) {
perror (delFileName);
exit( FALSE);
}
}
do_exit(exit_code);
}
/* ========================================================================
* Free all dynamically allocated variables and exit with the given code.
*/
local void do_exit(int exitcode)
{
static int in_exit = 0;
if (in_exit) exit(exitcode);
in_exit = 1;
if (env != NULL) free(env), env = NULL;
if (args != NULL) free((char*)args), args = NULL;
FREE(inbuf);
FREE(outbuf);
FREE(d_buf);
FREE(window);
#ifndef MAXSEG_64K
FREE(tab_prefix);
#else
FREE(tab_prefix0);
FREE(tab_prefix1);
#endif
exit(exitcode);
}
/* trees.c -- output deflated data using Huffman coding
* Copyright (C) 1992-1993 Jean-loup Gailly
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*/
/*
* PURPOSE
*
* Encode various sets of source values using variable-length
* binary code trees.
*
* DISCUSSION
*
* The PKZIP "deflation" process uses several Huffman trees. The more
* common source values are represented by shorter bit sequences.
*
* Each code tree is stored in the ZIP file in a compressed form
* which is itself a Huffman encoding of the lengths of
* all the code strings (in ascending order by source values).
* The actual code strings are reconstructed from the lengths in
* the UNZIP process, as described in the "application note"
* (APPNOTE.TXT) distributed as part of PKWARE's PKZIP program.
*
* REFERENCES
*
* Lynch, Thomas J.
* Data Compression: Techniques and Applications, pp. 53-55.
* Lifetime Learning Publications, 1985. ISBN 0-534-03418-7.
*
* Storer, James A.
* Data Compression: Methods and Theory, pp. 49-50.
* Computer Science Press, 1988. ISBN 0-7167-8156-5.
*
* Sedgewick, R.
* Algorithms, p290.
* Addison-Wesley, 1983. ISBN 0-201-06672-6.
*
* INTERFACE
*
* void ct_init (ush *attr, int *methodp)
* Allocate the match buffer, initialize the various tables and save
* the location of the internal file attribute (ascii/binary) and
* method (DEFLATE/STORE)
*
* void ct_tally (int dist, int lc);
* Save the match info and tally the frequency counts.
*
* long flush_block (char *buf, ulg stored_len, int eof)
* Determine the best encoding for the current block: dynamic trees,
* static trees or store, and output the encoded block to the zip
* file. Returns the total compressed length for the file so far.
*
*/
#include <ctype.h>
/* ===========================================================================
* Constants
*/
#define MAX_BITS 15
/* All codes must not exceed MAX_BITS bits */
#define MAX_BL_BITS 7
/* Bit length codes must not exceed MAX_BL_BITS bits */
#define LENGTH_CODES 29
/* number of length codes, not counting the special END_BLOCK code */
#define LITERALS 256
/* number of literal bytes 0..255 */
#define END_BLOCK 256
/* end of block literal code */
#define L_CODES (LITERALS+1+LENGTH_CODES)
/* number of Literal or Length codes, including the END_BLOCK code */
#define D_CODES 30
/* number of distance codes */
#define BL_CODES 19
/* number of codes used to transfer the bit lengths */
local int near extra_lbits[LENGTH_CODES] /* extra bits for each length code */
= {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};
local int near extra_dbits[D_CODES] /* extra bits for each distance code */
= {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};
local int near extra_blbits[BL_CODES]/* extra bits for each bit length code */
= {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};
#define STORED_BLOCK 0
#define STATIC_TREES 1
#define DYN_TREES 2
/* The three kinds of block type */
#ifndef LIT_BUFSIZE
# ifdef SMALL_MEM
# define LIT_BUFSIZE 0x2000
# else
# ifdef MEDIUM_MEM
# define LIT_BUFSIZE 0x4000
# else
# define LIT_BUFSIZE 0x8000
# endif
# endif
#endif
#ifndef DIST_BUFSIZE
# define DIST_BUFSIZE LIT_BUFSIZE
#endif
/* Sizes of match buffers for literals/lengths and distances. There are
* 4 reasons for limiting LIT_BUFSIZE to 64K:
* - frequencies can be kept in 16 bit counters
* - if compression is not successful for the first block, all input data is
* still in the window so we can still emit a stored block even when input
* comes from standard input. (This can also be done for all blocks if
* LIT_BUFSIZE is not greater than 32K.)
* - if compression is not successful for a file smaller than 64K, we can
* even emit a stored file instead of a stored block (saving 5 bytes).
* - creating new Huffman trees less frequently may not provide fast
* adaptation to changes in the input data statistics. (Take for
* example a binary file with poorly compressible code followed by
* a highly compressible string table.) Smaller buffer sizes give
* fast adaptation but have of course the overhead of transmitting trees
* more frequently.
* - I can't count above 4
* The current code is general and allows DIST_BUFSIZE < LIT_BUFSIZE (to save
* memory at the expense of compression). Some optimizations would be possible
* if we rely on DIST_BUFSIZE == LIT_BUFSIZE.
*/
#if LIT_BUFSIZE > INBUFSIZ
error cannot overlay l_buf and inbuf
#endif
#define REP_3_6 16
/* repeat previous bit length 3-6 times (2 bits of repeat count) */
#define REPZ_3_10 17
/* repeat a zero length 3-10 times (3 bits of repeat count) */
#define REPZ_11_138 18
/* repeat a zero length 11-138 times (7 bits of repeat count) */
/* ===========================================================================
* Local data
*/
/* Data structure describing a single value and its code string. */
typedef struct ct_data {
union {
ush freq; /* frequency count */
ush code; /* bit string */
} fc;
union {
ush dad; /* father node in Huffman tree */
ush len; /* length of bit string */
} dl;
} ct_data;
#define Freq fc.freq
#define Code fc.code
#define Dad dl.dad
#define Len dl.len
#define HEAP_SIZE (2*L_CODES+1)
/* maximum heap size */
local ct_data near dyn_ltree[HEAP_SIZE]; /* literal and length tree */
local ct_data near dyn_dtree[2*D_CODES+1]; /* distance tree */
local ct_data near static_ltree[L_CODES+2];
/* The static literal tree. Since the bit lengths are imposed, there is no
* need for the L_CODES extra codes used during heap construction. However
* The codes 286 and 287 are needed to build a canonical tree (see ct_init
* below).
*/
local ct_data near static_dtree[D_CODES];
/* The static distance tree. (Actually a trivial tree since all codes use
* 5 bits.)
*/
local ct_data near bl_tree[2*BL_CODES+1];
/* Huffman tree for the bit lengths */
typedef struct tree_desc {
ct_data near *dyn_tree; /* the dynamic tree */
ct_data near *static_tree; /* corresponding static tree or NULL */
int near *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;
local tree_desc near l_desc =
{dyn_ltree, static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS, 0};
local tree_desc near d_desc =
{dyn_dtree, static_dtree, extra_dbits, 0, D_CODES, MAX_BITS, 0};
local tree_desc near bl_desc =
{bl_tree, (ct_data near *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS, 0};
local ush near bl_count[MAX_BITS+1];
/* number of codes at each bit length for an optimal tree */
local uch near bl_order[BL_CODES]
= {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};
/* The lengths of the bit length codes are sent in order of decreasing
* probability, to avoid transmitting the lengths for unused bit length codes.
*/
local int near heap[2*L_CODES+1]; /* heap used to build the Huffman trees */
local int heap_len; /* number of elements in the heap */
local 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.
*/
local uch near depth[2*L_CODES+1];
/* Depth of each subtree used as tie breaker for trees of equal frequency */
local uch length_code[MAX_MATCH-MIN_MATCH+1];
/* length code for each normalized match length (0 == MIN_MATCH) */
local 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.
*/
local int near base_length[LENGTH_CODES];
/* First normalized length for each code (0 = MIN_MATCH) */
local int near 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 */
local uch near 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.
*/
local unsigned last_lit; /* running index in l_buf */
local unsigned last_dist; /* running index in d_buf */
local unsigned last_flags; /* running index in flag_buf */
local uch flags; /* current flags not yet saved in flag_buf */
local 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.
*/
local ulg opt_len; /* bit length of current block with optimal trees */
local ulg static_len; /* bit length of current block with static trees */
local ulg compressed_len; /* total bit length of compressed file */
local ulg input_len; /* total byte length of input file */
/* input_len is for debugging only since we can get it by other means. */
ush *file_type; /* pointer to UNKNOWN, BINARY or ASCII */
int *file_method; /* pointer to DEFLATE or STORE */
#ifdef DEBUG
extern ulg bits_sent; /* bit length of the compressed data */
extern long isize; /* byte length of input file */
#endif
extern long block_start; /* window offset of current block */
extern unsigned near strstart; /* window offset of current string */
/* ===========================================================================
* Local (static) routines in this file.
*/
local void init_block OF((void));
local void pqdownheap OF((ct_data near *tree, int k));
local void gen_bitlen OF((tree_desc near *desc));
local void gen_codes OF((ct_data near *tree, int max_code));
local void build_tree OF((tree_desc near *desc));
local void scan_tree OF((ct_data near *tree, int max_code));
local void send_tree OF((ct_data near *tree, int max_code));
local int build_bl_tree OF((void));
local void send_all_trees OF((int lcodes, int dcodes, int blcodes));
local void compress_block OF((ct_data near *ltree, ct_data near *dtree));
local void set_file_type OF((void));
#ifndef DEBUG
# define send_code(c, tree) send_bits(tree[c].Code, tree[c].Len)
/* Send a code of the given tree. c and tree must not have side effects */
#else /* DEBUG */
# define send_code(c, tree) \
{ if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \
send_bits(tree[c].Code, tree[c].Len); }
#endif
#define d_code(dist) \
((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)])
/* Mapping from a distance to a distance code. dist is the distance - 1 and
* must not have side effects. dist_code[256] and dist_code[257] are never
* used.
*/
#define MAX(a,b) (a >= b ? a : b)
/* 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).
*/
void ct_init(attr, methodp)
ush *attr; /* pointer to internal file attribute */
int *methodp; /* pointer to compression method */
{
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 = input_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 near *)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.
*/
local void init_block()
{
int n; /* iterates over tree elements */
/* Initialize the trees. */
for (n = 0; n < L_CODES; n++) dyn_ltree[n].Freq = 0;
for (n = 0; n < D_CODES; n++) dyn_dtree[n].Freq = 0;
for (n = 0; n < BL_CODES; n++) bl_tree[n].Freq = 0;
dyn_ltree[END_BLOCK].Freq = 1;
opt_len = static_len = 0L;
last_lit = last_dist = last_flags = 0;
flags = 0; flag_bit = 1;
}
#define SMALLEST 1
/* Index within the heap array of least frequent node in the Huffman tree */
/* ===========================================================================
* Remove the smallest element from the heap and recreate the heap with
* one less element. Updates heap and heap_len.
*/
#define pqremove(tree, top) \
{\
top = heap[SMALLEST]; \
heap[SMALLEST] = heap[heap_len--]; \
pqdownheap(tree, SMALLEST); \
}
/* ===========================================================================
* Compares to subtrees, using the tree depth as tie breaker when
* the subtrees have equal frequency. This minimizes the worst case length.
*/
#define smaller(tree, n, m) \
(tree[n].Freq < tree[m].Freq || \
(tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))
/* ===========================================================================
* Restore the heap property by moving down the tree starting at node k,
* exchanging a node with the smallest of its two sons if necessary, stopping
* when the heap property is re-established (each father smaller than its
* two sons).
*/
local void pqdownheap(tree, k)
ct_data near *tree; /* the tree to restore */
int k; /* node to move down */
{
int v = heap[k];
int j = k << 1; /* left son of k */
while (j <= heap_len) {
/* Set j to the smallest of the two sons: */
if (j < heap_len && smaller(tree, heap[j+1], heap[j])) j++;
/* Exit if v is smaller than both sons */
if (smaller(tree, v, heap[j])) break;
/* Exchange v with the smallest son */
heap[k] = heap[j]; k = j;
/* And continue down the tree, setting j to the left son of k */
j <<= 1;
}
heap[k] = v;
}
/* ===========================================================================
* Compute the optimal bit lengths for a tree and update the total bit length
* for the current block.
* IN assertion: the fields freq and dad are set, heap[heap_max] and
* above are the tree nodes sorted by increasing frequency.
* OUT assertions: the field len is set to the optimal bit length, the
* array bl_count contains the frequencies for each bit length.
* The length opt_len is updated; static_len is also updated if stree is
* not null.
*/
local void gen_bitlen(desc)
tree_desc near *desc; /* the tree descriptor */
{
ct_data near *tree = desc->dyn_tree;
int near *extra = desc->extra_bits;
int base = desc->extra_base;
int max_code = desc->max_code;
int max_length = desc->max_length;
ct_data near *stree = desc->static_tree;
int h; /* heap index */
int n, m; /* iterate over the tree elements */
int bits; /* bit length */
int xbits; /* extra bits */
ush f; /* frequency */
int overflow = 0; /* number of elements with bit length too large */
for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
/* In a first pass, compute the optimal bit lengths (which may
* overflow in the case of the bit length tree).
*/
tree[heap[heap_max]].Len = 0; /* root of the heap */
for (h = heap_max+1; h < HEAP_SIZE; h++) {
n = heap[h];
bits = tree[tree[n].Dad].Len + 1;
if (bits > max_length) bits = max_length, overflow++;
tree[n].Len = (ush)bits;
/* We overwrite tree[n].Dad which is no longer needed */
if (n > max_code) continue; /* not a leaf node */
bl_count[bits]++;
xbits = 0;
if (n >= base) xbits = extra[n-base];
f = tree[n].Freq;
opt_len += (ulg)f * (bits + xbits);
if (stree) static_len += (ulg)f * (stree[n].Len + xbits);
}
if (overflow == 0) return;
Trace((stderr,"\nbit length overflow\n"));
/* This happens for example on obj2 and pic of the Calgary corpus */
/* Find the first bit length which could increase: */
do {
bits = max_length-1;
while (bl_count[bits] == 0) bits--;
bl_count[bits]--; /* move one leaf down the tree */
bl_count[bits+1] += 2; /* move one overflow item as its brother */
bl_count[max_length]--;
/* The brother of the overflow item also moves one step up,
* but this does not affect bl_count[max_length]
*/
overflow -= 2;
} while (overflow > 0);
/* Now recompute all bit lengths, scanning in increasing frequency.
* h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
* lengths instead of fixing only the wrong ones. This idea is taken
* from 'ar' written by Haruhiko Okumura.)
*/
for (bits = max_length; bits != 0; bits--) {
n = bl_count[bits];
while (n != 0) {
m = heap[--h];
if (m > max_code) continue;
if (tree[m].Len != (unsigned) bits) {
Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
opt_len += ((long)bits-(long)tree[m].Len)*(long)tree[m].Freq;
tree[m].Len = (ush)bits;
}
n--;
}
}
}
/* ===========================================================================
* Generate the codes for a given tree and bit counts (which need not be
* optimal).
* IN assertion: the array bl_count contains the bit length statistics for
* the given tree and the field len is set for all tree elements.
* OUT assertion: the field code is set for all tree elements of non
* zero code length.
*/
local void gen_codes (tree, max_code)
ct_data near *tree; /* the tree to decorate */
int max_code; /* largest code with non zero frequency */
{
ush next_code[MAX_BITS+1]; /* next code value for each bit length */
ush code = 0; /* running code value */
int bits; /* bit index */
int n; /* code index */
/* The distribution counts are first used to generate the code values
* without bit reversal.
*/
for (bits = 1; bits <= MAX_BITS; bits++) {
next_code[bits] = code = (code + bl_count[bits-1]) << 1;
}
/* Check that the bit counts in bl_count are consistent. The last code
* must be all ones.
*/
Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,
"inconsistent bit counts");
Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
for (n = 0; n <= max_code; n++) {
int len = tree[n].Len;
if (len == 0) continue;
/* Now reverse the bits */
tree[n].Code = bi_reverse(next_code[len]++, len);
Tracec(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",
n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));
}
}
/* ===========================================================================
* Construct one Huffman tree and assigns the code bit strings and lengths.
* Update the total bit length for the current block.
* IN assertion: the field freq is set for all tree elements.
* OUT assertions: the fields len and code are set to the optimal bit length
* and corresponding code. The length opt_len is updated; static_len is
* also updated if stree is not null. The field max_code is set.
*/
local void build_tree(desc)
tree_desc near *desc; /* the tree descriptor */
{
ct_data near *tree = desc->dyn_tree;
ct_data near *stree = desc->static_tree;
int elems = desc->elems;
int n, m; /* iterate over heap elements */
int max_code = -1; /* largest code with non zero frequency */
int node = elems; /* next internal node of the tree */
/* Construct the initial heap, with least frequent element in
* heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
* heap[0] is not used.
*/
heap_len = 0, heap_max = HEAP_SIZE;
for (n = 0; n < elems; n++) {
if (tree[n].Freq != 0) {
heap[++heap_len] = max_code = n;
depth[n] = 0;
} else {
tree[n].Len = 0;
}
}
/* The pkzip format requires that at least one distance code exists,
* and that at least one bit should be sent even if there is only one
* possible code. So to avoid special checks later on we force at least
* two codes of non zero frequency.
*/
while (heap_len < 2) {
int new = heap[++heap_len] = (max_code < 2 ? ++max_code : 0);
tree[new].Freq = 1;
depth[new] = 0;
opt_len--; if (stree) static_len -= stree[new].Len;
/* new is 0 or 1 so it does not have extra bits */
}
desc->max_code = max_code;
/* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
* establish sub-heaps of increasing lengths:
*/
for (n = heap_len/2; n >= 1; n--) pqdownheap(tree, n);
/* Construct the Huffman tree by repeatedly combining the least two
* frequent nodes.
*/
do {
pqremove(tree, n); /* n = node of least frequency */
m = heap[SMALLEST]; /* m = node of next least frequency */
heap[--heap_max] = n; /* keep the nodes sorted by frequency */
heap[--heap_max] = m;
/* Create a new node father of n and m */
tree[node].Freq = tree[n].Freq + tree[m].Freq;
depth[node] = (uch) (MAX(depth[n], depth[m]) + 1);
tree[n].Dad = tree[m].Dad = (ush)node;
#ifdef DUMP_BL_TREE
if (tree == bl_tree) {
fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",
node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);
}
#endif
/* and insert the new node in the heap */
heap[SMALLEST] = node++;
pqdownheap(tree, SMALLEST);
} while (heap_len >= 2);
heap[--heap_max] = heap[SMALLEST];
/* At this point, the fields freq and dad are set. We can now
* generate the bit lengths.
*/
gen_bitlen((tree_desc near *)desc);
/* The field len is now set, we can generate the bit codes */
gen_codes ((ct_data near *)tree, max_code);
}
/* ===========================================================================
* Scan a literal or distance tree to determine the frequencies of the codes
* in the bit length tree. Updates opt_len to take into account the repeat
* counts. (The contribution of the bit length codes will be added later
* during the construction of bl_tree.)
*/
local void scan_tree (tree, max_code)
ct_data near *tree; /* the tree to be scanned */
int max_code; /* and its largest code of non zero frequency */
{
int n; /* iterates over all tree elements */
int prevlen = -1; /* last emitted length */
int curlen; /* length of current code */
int nextlen = tree[0].Len; /* length of next code */
int count = 0; /* repeat count of the current code */
int max_count = 7; /* max repeat count */
int min_count = 4; /* min repeat count */
if (nextlen == 0) max_count = 138, min_count = 3;
tree[max_code+1].Len = (ush)0xffff; /* guard */
for (n = 0; n <= max_code; n++) {
curlen = nextlen; nextlen = tree[n+1].Len;
if (++count < max_count && curlen == nextlen) {
continue;
} else if (count < min_count) {
bl_tree[curlen].Freq += count;
} else if (curlen != 0) {
if (curlen != prevlen) bl_tree[curlen].Freq++;
bl_tree[REP_3_6].Freq++;
} else if (count <= 10) {
bl_tree[REPZ_3_10].Freq++;
} else {
bl_tree[REPZ_11_138].Freq++;
}
count = 0; prevlen = curlen;
if (nextlen == 0) {
max_count = 138, min_count = 3;
} else if (curlen == nextlen) {
max_count = 6, min_count = 3;
} else {
max_count = 7, min_count = 4;
}
}
}
/* ===========================================================================
* Send a literal or distance tree in compressed form, using the codes in
* bl_tree.
*/
local void send_tree (tree, max_code)
ct_data near *tree; /* the tree to be scanned */
int max_code; /* and its largest code of non zero frequency */
{
int n; /* iterates over all tree elements */
int prevlen = -1; /* last emitted length */
int curlen; /* length of current code */
int nextlen = tree[0].Len; /* length of next code */
int count = 0; /* repeat count of the current code */
int max_count = 7; /* max repeat count */
int min_count = 4; /* min repeat count */
/* tree[max_code+1].Len = -1; */ /* guard already set */
if (nextlen == 0) max_count = 138, min_count = 3;
for (n = 0; n <= max_code; n++) {
curlen = nextlen; nextlen = tree[n+1].Len;
if (++count < max_count && curlen == nextlen) {
continue;
} else if (count < min_count) {
do { send_code(curlen, bl_tree); } while (--count != 0);
} else if (curlen != 0) {
if (curlen != prevlen) {
send_code(curlen, bl_tree); count--;
}
Assert(count >= 3 && count <= 6, " 3_6?");
send_code(REP_3_6, bl_tree); send_bits(count-3, 2);
} else if (count <= 10) {
send_code(REPZ_3_10, bl_tree); send_bits(count-3, 3);
} else {
send_code(REPZ_11_138, bl_tree); send_bits(count-11, 7);
}
count = 0; prevlen = curlen;
if (nextlen == 0) {
max_count = 138, min_count = 3;
} else if (curlen == nextlen) {
max_count = 6, min_count = 3;
} else {
max_count = 7, min_count = 4;
}
}
}
/* ===========================================================================
* Construct the Huffman tree for the bit lengths and return the index in
* bl_order of the last bit length code to send.
*/
local int build_bl_tree()
{
int max_blindex; /* index of last bit length code of non zero freq */
/* Determine the bit length frequencies for literal and distance trees */
scan_tree((ct_data near *)dyn_ltree, l_desc.max_code);
scan_tree((ct_data near *)dyn_dtree, d_desc.max_code);
/* Build the bit length tree: */
build_tree((tree_desc near *)(&bl_desc));
/* opt_len now includes the length of the tree representations, except
* the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
*/
/* Determine the number of bit length codes to send. The pkzip format
* requires that at least 4 bit length codes be sent. (appnote.txt says
* 3 but the actual value used is 4.)
*/
for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
if (bl_tree[bl_order[max_blindex]].Len != 0) break;
}
/* Update opt_len to include the bit length tree and counts */
opt_len += 3*(max_blindex+1) + 5+5+4;
Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", opt_len, static_len));
return max_blindex;
}
/* ===========================================================================
* Send the header for a block using dynamic Huffman trees: the counts, the
* lengths of the bit length codes, the literal tree and the distance tree.
* IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
*/
local void send_all_trees(lcodes, dcodes, blcodes)
int lcodes, dcodes, blcodes; /* number of codes for each tree */
{
int rank; /* index in bl_order */
Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");
Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,
"too many codes");
Tracev((stderr, "\nbl counts: "));
send_bits(lcodes-257, 5); /* not +255 as stated in appnote.txt */
send_bits(dcodes-1, 5);
send_bits(blcodes-4, 4); /* not -3 as stated in appnote.txt */
for (rank = 0; rank < blcodes; rank++) {
Tracev((stderr, "\nbl code %2d ", bl_order[rank]));
send_bits(bl_tree[bl_order[rank]].Len, 3);
}
Tracev((stderr, "\nbl tree: sent %ld", bits_sent));
send_tree((ct_data near *)dyn_ltree, lcodes-1); /* send the literal tree */
Tracev((stderr, "\nlit tree: sent %ld", bits_sent));
send_tree((ct_data near *)dyn_dtree, dcodes-1); /* send the distance tree */
Tracev((stderr, "\ndist tree: sent %ld", bits_sent));
}
/* ===========================================================================
* Determine the best encoding for the current block: dynamic trees, static
* trees or store, and output the encoded block to the zip file. This function
* returns the total compressed length for the file so far.
*/
ulg flush_block(buf, stored_len, eof)
char *buf; /* input block, or NULL if too old */
ulg stored_len; /* length of input block */
int eof; /* true if this is the last block for a file */
{
ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
int max_blindex; /* index of last bit length code of non zero freq */
flag_buf[last_flags] = flags; /* Save the flags for the last 8 items */
/* Check if the file is ascii or binary */
if (*file_type == (ush)UNKNOWN) set_file_type();
/* Construct the literal and distance trees */
build_tree((tree_desc near *)(&l_desc));
Tracev((stderr, "\nlit data: dyn %ld, stat %ld", opt_len, static_len));
build_tree((tree_desc near *)(&d_desc));
Tracev((stderr, "\ndist data: dyn %ld, stat %ld", opt_len, static_len));
/* At this point, opt_len and static_len are the total bit lengths of
* the compressed block data, excluding the tree representations.
*/
/* Build the bit length tree for the above two trees, and get the index
* in bl_order of the last bit length code to send.
*/
max_blindex = build_bl_tree();
/* Determine the best encoding. Compute first the block length in bytes */
opt_lenb = (opt_len+3+7)>>3;
static_lenb = (static_len+3+7)>>3;
input_len += stored_len; /* for debugging only */
Trace((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u dist %u ",
opt_lenb, opt_len, static_lenb, static_len, stored_len,
last_lit, last_dist));
if (static_lenb <= opt_lenb) opt_lenb = static_lenb;
/* If compression failed and this is the first and last block,
* and if the zip file can be seeked (to rewrite the local header),
* the whole file is transformed into a stored file:
*/
#ifdef FORCE_METHOD
#else
if (stored_len <= opt_lenb && eof && compressed_len == 0L && seekable()) {
#endif
/* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */
if (buf == (char*)0) error ("block vanished");
copy_block(buf, (unsigned)stored_len, 0); /* without header */
compressed_len = stored_len << 3;
*file_method = STORED;
#ifdef FORCE_METHOD
#else
} else if (stored_len+4 <= opt_lenb && buf != (char*)0) {
/* 4: two words for the lengths */
#endif
/* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
* Otherwise we can't have processed more than WSIZE input bytes since
* the last block flush, because compression would have been
* successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
* transform a block into a stored block.
*/
send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */
compressed_len = (compressed_len + 3 + 7) & ~7L;
compressed_len += (stored_len + 4) << 3;
copy_block(buf, (unsigned)stored_len, 1); /* with header */
#ifdef FORCE_METHOD
#else
} else if (static_lenb == opt_lenb) {
#endif
send_bits((STATIC_TREES<<1)+eof, 3);
compress_block((ct_data near *)static_ltree, (ct_data near *)static_dtree);
compressed_len += 3 + static_len;
} else {
send_bits((DYN_TREES<<1)+eof, 3);
send_all_trees(l_desc.max_code+1, d_desc.max_code+1, max_blindex+1);
compress_block((ct_data near *)dyn_ltree, (ct_data near *)dyn_dtree);
compressed_len += 3 + opt_len;
}
Assert (compressed_len == bits_sent, "bad compressed size");
init_block();
if (eof) {
Assert (input_len == isize, "bad input size");
bi_windup();
compressed_len += 7; /* align on byte boundary */
}
Tracev((stderr,"\ncomprlen %lu(%lu) ", compressed_len>>3,
compressed_len-7*eof));
return compressed_len >> 3;
}
/* ===========================================================================
* Save the match info and tally the frequency counts. Return true if
* the current block must be flushed.
*/
int ct_tally (dist, lc)
int dist; /* distance of matched string */
int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */
{
l_buf[last_lit++] = (uch)lc;
if (dist == 0) {
/* lc is the unmatched char */
dyn_ltree[lc].Freq++;
} else {
/* Here, lc is the match length - MIN_MATCH */
dist--; /* dist = match distance - 1 */
Assert((ush)dist < (ush)MAX_DIST &&
(ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&
(ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match");
dyn_ltree[length_code[lc]+LITERALS+1].Freq++;
dyn_dtree[d_code(dist)].Freq++;
d_buf[last_dist++] = (ush)dist;
flags |= flag_bit;
}
flag_bit <<= 1;
/* Output the flags if they fill a byte: */
if ((last_lit & 7) == 0) {
flag_buf[last_flags++] = flags;
flags = 0, flag_bit = 1;
}
/* Try to guess if it is profitable to stop the current block here */
if ((last_lit & 0xfff) == 0) {
/* Compute an upper bound for the compressed length */
ulg out_length = (ulg)last_lit*8L;
ulg in_length = (ulg)strstart-block_start;
int dcode;
for (dcode = 0; dcode < D_CODES; dcode++) {
out_length += (ulg)dyn_dtree[dcode].Freq*(5L+extra_dbits[dcode]);
}
out_length >>= 3;
Trace((stderr,"\nlast_lit %u, last_dist %u, in %ld, out ~%ld(%ld%%) ",
last_lit, last_dist, in_length, out_length,
100L - out_length*100L/in_length));
if (last_dist < last_lit/2 && out_length < in_length/2) return 1;
}
return (last_lit == LIT_BUFSIZE-1 || last_dist == DIST_BUFSIZE);
/* We avoid equality with LIT_BUFSIZE because of wraparound at 64K
* on 16 bit machines and because stored blocks are restricted to
* 64K-1 bytes.
*/
}
/* ===========================================================================
* Send the block data compressed using the given Huffman trees
*/
local void compress_block(ltree, dtree)
ct_data near *ltree; /* literal tree */
ct_data near *dtree; /* distance tree */
{
unsigned dist; /* distance of matched string */
int lc; /* match length or unmatched char (if dist == 0) */
unsigned lx = 0; /* running index in l_buf */
unsigned dx = 0; /* running index in d_buf */
unsigned fx = 0; /* running index in flag_buf */
uch flag = 0; /* current flags */
unsigned code; /* the code to send */
int extra; /* number of extra bits to send */
if (last_lit != 0) do {
if ((lx & 7) == 0) flag = flag_buf[fx++];
lc = l_buf[lx++];
if ((flag & 1) == 0) {
send_code(lc, ltree); /* send a literal byte */
Tracecv(isgraph(lc), (stderr," '%c' ", lc));
} else {
/* Here, lc is the match length - MIN_MATCH */
code = length_code[lc];
send_code(code+LITERALS+1, ltree); /* send the length code */
extra = extra_lbits[code];
if (extra != 0) {
lc -= base_length[code];
send_bits(lc, extra); /* send the extra length bits */
}
dist = d_buf[dx++];
/* Here, dist is the match distance - 1 */
code = d_code(dist);
Assert (code < D_CODES, "bad d_code");
send_code(code, dtree); /* send the distance code */
extra = extra_dbits[code];
if (extra != 0) {
dist -= base_dist[code];
send_bits(dist, extra); /* send the extra distance bits */
}
} /* literal or match pair ? */
flag >>= 1;
} while (lx < last_lit);
send_code(END_BLOCK, ltree);
}
/* ===========================================================================
* Set the file type to ASCII or BINARY, using a crude approximation:
* binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
* IN assertion: the fields freq of dyn_ltree are set and the total of all
* frequencies does not exceed 64K (to fit in an int on 16 bit machines).
*/
local void set_file_type()
{
int n = 0;
unsigned ascii_freq = 0;
unsigned bin_freq = 0;
while (n < 7) bin_freq += dyn_ltree[n++].Freq;
while (n < 128) ascii_freq += dyn_ltree[n++].Freq;
while (n < LITERALS) bin_freq += dyn_ltree[n++].Freq;
*file_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII;
if (*file_type == BINARY && translate_eol) {
warn("-l used on binary file", "");
}
}
/* util.c -- utility functions for gzip support
* 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.
*/
#include <ctype.h>
#include <errno.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifndef NO_FCNTL_H
# include <fcntl.h>
#endif
#if defined(STDC_HEADERS) || !defined(NO_STDLIB_H)
# include <stdlib.h>
#else
extern int errno;
#endif
/* ===========================================================================
* Copy input to output unchanged: zcat == cat with --force.
* IN assertion: insize bytes have already been read in inbuf.
*/
int copy(in, out)
int in, out; /* input and output file descriptors */
{
errno = 0;
while (insize != 0 && (int)insize != EOF) {
write_buf(out, (char*)inbuf, insize);
bytes_out += insize;
insize = read(in, (char*)inbuf, INBUFSIZ);
}
if ((int)insize == EOF && errno != 0) {
read_error();
}
bytes_in = bytes_out;
return OK;
}
/* ========================================================================
* Put string s in lower case, return s.
*/
char *strlwr(s)
char *s;
{
char *t;
for (t = s; *t; t++) *t = tolow(*t);
return s;
}
#if defined(NO_STRING_H) && !defined(STDC_HEADERS)
/* Provide missing strspn and strcspn functions. */
# ifndef __STDC__
# define const
# endif
int strspn OF((const char *s, const char *accept));
int strcspn OF((const char *s, const char *reject));
/* ========================================================================
* Return the length of the maximum initial segment
* of s which contains only characters in accept.
*/
int strspn(s, accept)
const char *s;
const char *accept;
{
register const char *p;
register const char *a;
register int count = 0;
for (p = s; *p != '\0'; ++p) {
for (a = accept; *a != '\0'; ++a) {
if (*p == *a) break;
}
if (*a == '\0') return count;
++count;
}
return count;
}
/* ========================================================================
* Return the length of the maximum inital segment of s
* which contains no characters from reject.
*/
int strcspn(s, reject)
const char *s;
const char *reject;
{
register int count = 0;
while (*s != '\0') {
if (strchr(reject, *s++) != NULL) return count;
++count;
}
return count;
}
#endif /* NO_STRING_H */
/* ========================================================================
* Add an environment variable (if any) before argv, and update argc.
* Return the expanded environment variable to be freed later, or NULL
* if no options were added to argv.
*/
#define SEPARATOR " \t" /* separators in env variable */
char *add_envopt(argcp, argvp, env)
int *argcp; /* pointer to argc */
char ***argvp; /* pointer to argv */
char *env; /* name of environment variable */
{
char *p; /* running pointer through env variable */
char **oargv; /* runs through old argv array */
char **nargv; /* runs through new argv array */
int oargc = *argcp; /* old argc */
int nargc = 0; /* number of arguments in env variable */
env = (char*)getenv(env);
if (env == NULL) return NULL;
p = (char*)xmalloc(strlen(env)+1);
env = strcpy(p, env); /* keep env variable intact */
for (p = env; *p; nargc++ ) { /* move through env */
p += strspn(p, SEPARATOR); /* skip leading separators */
if (*p == '\0') break;
p += strcspn(p, SEPARATOR); /* find end of word */
if (*p) *p++ = '\0'; /* mark it */
}
if (nargc == 0) {
free(env);
return NULL;
}
*argcp += nargc;
/* Allocate the new argv array, with an extra element just in case
* the original arg list did not end with a NULL.
*/
nargv = (char**)calloc(*argcp+1, sizeof(char *));
if (nargv == NULL) error("out of memory");
oargv = *argvp;
*argvp = nargv;
/* Copy the program name first */
if (oargc-- < 0) error("argc<=0");
*(nargv++) = *(oargv++);
/* Then copy the environment args */
for (p = env; nargc > 0; nargc--) {
p += strspn(p, SEPARATOR); /* skip separators */
*(nargv++) = p; /* store start */
while (*p++) ; /* skip over word */
}
/* Finally copy the old args and add a NULL (usual convention) */
while (oargc--) *(nargv++) = *(oargv++);
*nargv = NULL;
return env;
}
/* ========================================================================
* Display compression ratio on the given stream on 6 characters.
*/
void display_ratio(num, den, file)
long num;
long den;
FILE *file;
{
long ratio; /* 1000 times the compression ratio */
if (den == 0) {
ratio = 0; /* no compression */
} else if (den < 2147483L) { /* (2**31 -1)/1000 */
ratio = 1000L*num/den;
} else {
ratio = num/(den/1000L);
}
if (ratio < 0) {
putc('-', file);
ratio = -ratio;
} else {
putc(' ', file);
}
fprintf(file, "%2ld.%1ld%%", ratio / 10L, ratio % 10L);
}
/* 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.
*/
#include <ctype.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifndef NO_FCNTL_H
# include <fcntl.h>
#endif
local ulg crc; /* crc on uncompressed file data */
long header_bytes; /* number of bytes in gzip header */
/* ===========================================================================
* Deflate in to out.
* IN assertions: the input and output buffers are cleared.
* The variables time_stamp and save_orig_name are initialized.
*/
int zip(in, out)
int in, out; /* input and output file descriptors */
{
uch flags = 0; /* general purpose bit flags */
ush attr = 0; /* ascii/binary flag */
ush deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
ifd = in;
ofd = out;
outcnt = 0;
/* Write the header to the gzip file. See algorithm.doc for the format */
method = DEFLATED;
put_byte(GZIP_MAGIC[0]); /* magic header */
put_byte(GZIP_MAGIC[1]);
put_byte(DEFLATED); /* compression method */
put_byte(flags); /* general flags */
put_long(time_stamp);
/* Write deflated file to zip file */
crc = updcrc(0, 0);
bi_init(out);
ct_init(&attr, &method);
lm_init(&deflate_flags);
put_byte((uch)deflate_flags); /* extra flags */
put_byte(OS_CODE); /* OS identifier */
header_bytes = (long)outcnt;
(void)deflate();
/* Write the crc and uncompressed size */
put_long(crc);
put_long(isize);
header_bytes += 2*sizeof(long);
flush_outbuf();
return OK;
}
/* ===========================================================================
* Read a new buffer from the current input file, perform end-of-line
* translation, and update the crc and input file size.
* IN assertion: size >= 2 (for end-of-line translation)
*/
int file_read(buf, size)
char *buf;
unsigned size;
{
unsigned len;
Assert(insize == 0, "inbuf not empty");
len = read(ifd, buf, size);
if (len == (unsigned)(-1) || len == 0) return (int)len;
crc = updcrc((uch*)buf, len);
isize += (ulg)len;
return (int)len;
}
#endif
Reference in New Issue View Git Blame Copy Permalink