/* 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 */ #include "internal.h" #ifdef BB_GZIP #ifndef BB_ZCAT #error you need zcat to have gzip support! #endif static const char gzip_usage[] = "gzip\nignores all command line arguments\ncompress stdin to stdout with -9 compression\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 #if !defined(NO_STRING_H) || defined(STDC_HEADERS) # include # if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__) # include # endif # define memzero(s, n) memset ((voidp)(s), 0, (n)) #else # include # 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 to_stdout; /* output to stdout (-c) */ 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); /* 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 /* $Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $ */ /* 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. */ /* $Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $ */ #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 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 # 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 # 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 # 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 # include # 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 # 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 # 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 # define unlink delete # ifdef VAXC # define NO_FCNTL_H # include # 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 /* 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 #endif #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #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 #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #endif /* =========================================================================== * 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-1 error: cannot overlay head with tab_prefix1 #endif #define HASH_SIZE (unsigned)(1<= 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)<= 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. */ #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #endif #include #include #include #include #include /* configuration */ #ifdef NO_TIME_H # include #else # include #endif #ifndef NO_FCNTL_H # include #endif #ifdef HAVE_UNISTD_H # include #endif #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H) # include #else extern int errno; #endif #if defined(DIRENT) # include 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 typedef struct direct dir_type; # define DIR_OPT "SYSDIR" # else # ifdef SYSNDIR # include typedef struct direct dir_type; # define DIR_OPT "SYSNDIR" # else # ifdef NDIR # include 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 # define TIME_OPT "UTIME" # else # ifdef HAVE_SYS_UTIME_H # include # 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 # 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< #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #endif /* =========================================================================== * 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< dist code (0..29) */ dist = 0; for (code = 0 ; code < 16; code++) { base_dist[code] = dist; for (n = 0; n < (1<>= 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<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. */ #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #endif #include #include #include #ifdef HAVE_UNISTD_H # include #endif #ifndef NO_FCNTL_H # include #endif #if defined(STDC_HEADERS) || !defined(NO_STDLIB_H) # include #else extern int errno; #endif extern ulg crc_32_tab[]; /* crc table, defined below */ /* =========================================================================== * 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. */ #ifdef RCSID static char rcsid[] = "$Id: gzip.c,v 1.4 1999/10/19 20:03:34 andersen Exp $"; #endif #include #include #ifdef HAVE_UNISTD_H # include #endif #ifndef NO_FCNTL_H # include #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