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ENH: Initial import
2006-08-01 00:59:20 +04:00
/*
* Copyright (c) 1985, 1986 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* James A. Woods, derived from original work by Spencer Thomas
* and Joseph Orost.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1985, 1986 The Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)compress.c 5.19 (Berkeley) 3/18/91";
#endif /* not lint */
/*
* compress.c - File compression ala IEEE Computer, June 1984.
*
* Authors: Spencer W. Thomas (decvax!utah-cs!thomas)
* Jim McKie (decvax!mcvax!jim)
* Steve Davies (decvax!vax135!petsd!peora!srd)
* Ken Turkowski (decvax!decwrl!turtlevax!ken)
* James A. Woods (decvax!ihnp4!ames!jaw)
* Joe Orost (decvax!vax135!petsd!joe)
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <signal.h>
#include <utime.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
/*
* Set USERMEM to the maximum amount of physical user memory available
* in bytes. USERMEM is used to determine the maximum BITS that can be used
* for compression.
*
* SACREDMEM is the amount of physical memory saved for others; compress
* will hog the rest.
*/
#ifndef SACREDMEM
#define SACREDMEM 0
#endif
#ifndef USERMEM
# define USERMEM 450000 /* default user memory */
#endif
#ifdef pdp11
# define BITS 12 /* max bits/code for 16-bit machine */
# define NO_UCHAR /* also if "unsigned char" functions as signed char */
# undef USERMEM
#endif /* pdp11 */ /* don't forget to compile with -i */
#ifdef USERMEM
# if USERMEM >= (433484+SACREDMEM)
# define PBITS 16
# else
# if USERMEM >= (229600+SACREDMEM)
# define PBITS 15
# else
# if USERMEM >= (127536+SACREDMEM)
# define PBITS 14
# else
# if USERMEM >= (73464+SACREDMEM)
# define PBITS 13
# else
# define PBITS 12
# endif
# endif
# endif
# endif
# undef USERMEM
#endif /* USERMEM */
#ifdef PBITS /* Preferred BITS for this memory size */
# ifndef BITS
# define BITS PBITS
# endif BITS
#endif /* PBITS */
#if BITS == 16
# define HSIZE 69001 /* 95% occupancy */
#endif
#if BITS == 15
# define HSIZE 35023 /* 94% occupancy */
#endif
#if BITS == 14
# define HSIZE 18013 /* 91% occupancy */
#endif
#if BITS == 13
# define HSIZE 9001 /* 91% occupancy */
#endif
#if BITS <= 12
# define HSIZE 5003 /* 80% occupancy */
#endif
/*
* a code_int must be able to hold 2**BITS values of type int, and also -1
*/
#if BITS > 15
typedef long int code_int;
#else
typedef int code_int;
#endif
#ifdef SIGNED_COMPARE_SLOW
typedef unsigned long int count_int;
typedef unsigned short int count_short;
#else
typedef long int count_int;
#endif
#ifdef NO_UCHAR
typedef char char_type;
#else
typedef unsigned char char_type;
#endif /* UCHAR */
char_type magic_header[] = { "\037\235" }; /* 1F 9D */
/* Defines for third byte of header */
#define BIT_MASK 0x1f
#define BLOCK_MASK 0x80
/* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is
a fourth header byte (for expansion).
*/
#define INIT_BITS 9 /* initial number of bits/code */
int n_bits; /* number of bits/code */
int maxbits = BITS; /* user settable max # bits/code */
code_int maxcode; /* maximum code, given n_bits */
code_int maxmaxcode = 1 << BITS; /* should NEVER generate this code */
#ifdef COMPATIBLE /* But wrong! */
# define MAXCODE(n_bits) (1 << (n_bits) - 1)
#else
# define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
#endif /* COMPATIBLE */
count_int htab [HSIZE];
unsigned short codetab [HSIZE];
#define htabof(i) htab[i]
#define codetabof(i) codetab[i]
code_int hsize = HSIZE; /* for dynamic table sizing */
count_int fsize;
/*
* To save much memory, we overlay the table used by compress() with those
* used by decompress(). The tab_prefix table is the same size and type
* as the codetab. The tab_suffix table needs 2**BITS characters. We
* get this from the beginning of htab. The output stack uses the rest
* of htab, and contains characters. There is plenty of room for any
* possible stack (stack used to be 8000 characters).
*/
#define tab_prefixof(i) codetabof(i)
# define tab_suffixof(i) ((char_type *)(htab))[i]
# define de_stack ((char_type *)&tab_suffixof(1<<BITS))
code_int free_ent = 0; /* first unused entry */
int exit_stat = 0; /* per-file status */
int perm_stat = 0; /* permanent status */
code_int getcode();
int nomagic = 0; /* Use a 3-byte magic number header, unless old file */
int zcat_flg = 0; /* Write output on stdout, suppress messages */
int precious = 1; /* Don't unlink output file on interrupt */
int quiet = 1; /* don't tell me about compression */
/*
* block compression parameters -- after all codes are used up,
* and compression rate changes, start over.
*/
int block_compress = BLOCK_MASK;
int clear_flg = 0;
long int ratio = 0;
#define CHECK_GAP 10000 /* ratio check interval */
count_int checkpoint = CHECK_GAP;
/*
* the next two codes should not be changed lightly, as they must not
* lie within the contiguous general code space.
*/
#define FIRST 257 /* first free entry */
#define CLEAR 256 /* table clear output code */
int force = 0;
char ofname [100];
#ifdef DEBUG
int debug, verbose;
#endif
sig_t oldint;
int bgnd_flag;
int do_decomp = 0;
/*-
* Algorithm from "A Technique for High Performance Data Compression",
* Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
*
* Usage: compress [-dfvc] [-b bits] [file ...]
* Inputs:
* -d: If given, decompression is done instead.
*
* -c: Write output on stdout, don't remove original.
*
* -b: Parameter limits the max number of bits/code.
*
* -f: Forces output file to be generated, even if one already
* exists, and even if no space is saved by compressing.
* If -f is not used, the user will be prompted if stdin is
* a tty, otherwise, the output file will not be overwritten.
*
* -v: Write compression statistics
*
* file ...: Files to be compressed. If none specified, stdin
* is used.
* Outputs:
* file.Z: Compressed form of file with same mode, owner, and utimes
* or stdout (if stdin used as input)
*
* Assumptions:
* When filenames are given, replaces with the compressed version
* (.Z suffix) only if the file decreases in size.
* Algorithm:
* Modified Lempel-Ziv method (LZW). Basically finds common
* substrings and replaces them with a variable size code. This is
* deterministic, and can be done on the fly. Thus, the decompression
* procedure needs no input table, but tracks the way the table was built.
*/
main(argc, argv)
int argc;
char **argv;
{
extern int optind;
extern char *optarg;
struct stat statbuf;
int ch, overwrite;
char **filelist, **fileptr, *cp, tempname[MAXPATHLEN];
void onintr(), oops();
/* This bg check only works for sh. */
if ((oldint = signal(SIGINT, SIG_IGN)) != SIG_IGN) {
(void)signal(SIGINT, onintr);
(void)signal(SIGSEGV, oops); /* XXX */
}
bgnd_flag = oldint != SIG_DFL;
#ifdef COMPATIBLE
nomagic = 1; /* Original didn't have a magic number */
#endif
if (cp = rindex(argv[0], '/'))
++cp;
else
cp = argv[0];
if (strcmp(cp, "uncompress") == 0)
do_decomp = 1;
else if(strcmp(cp, "zcat") == 0) {
do_decomp = 1;
zcat_flg = 1;
}
/*
* -b maxbits => maxbits.
* -C => generate output compatible with compress 2.0.
* -c => cat all output to stdout
* -D => debug
* -d => do_decomp
* -f => force overwrite of output file
* -n => no header: useful to uncompress old files
* -V => print Version; debug verbose
* -v => unquiet
*/
overwrite = 0;
#ifdef DEBUG
while ((ch = getopt(argc, argv, "b:CcDdfnVv")) != EOF)
#else
while ((ch = getopt(argc, argv, "b:Ccdfnv")) != EOF)
#endif
switch(ch) {
case 'b':
maxbits = atoi(optarg);
break;
case 'C':
block_compress = 0;
break;
case 'c':
zcat_flg = 1;
break;
#ifdef DEBUG
case 'D':
debug = 1;
break;
#endif
case 'd':
do_decomp = 1;
break;
case 'f':
overwrite = 1;
force = 1;
break;
case 'n':
nomagic = 1;
break;
case 'q':
quiet = 1;
break;
#ifdef DEBUG
case 'V':
verbose = 1;
break;
#endif
case 'v':
quiet = 0;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (maxbits < INIT_BITS)
maxbits = INIT_BITS;
if (maxbits > BITS)
maxbits = BITS;
maxmaxcode = 1 << maxbits;
/* Build useless input file list. */
filelist = fileptr = (char **)(malloc(argc * sizeof(*argv)));
while (*argv)
*fileptr++ = *argv++;
*fileptr = NULL;
if (*filelist != NULL) {
for (fileptr = filelist; *fileptr; fileptr++) {
exit_stat = 0;
if (do_decomp) { /* DECOMPRESSION */
/* Check for .Z suffix */
if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") != 0) {
/* No .Z: tack one on */
strcpy(tempname, *fileptr);
strcat(tempname, ".Z");
*fileptr = tempname;
}
/* Open input file */
if ((freopen(*fileptr, "r", stdin)) == NULL) {
perror(*fileptr);
perm_stat = 1;
continue;
}
/* Check the magic number */
if (nomagic == 0) {
if ((getchar() != (magic_header[0] & 0xFF))
|| (getchar() != (magic_header[1] & 0xFF))) {
fprintf(stderr, "%s: not in compressed format\n",
*fileptr);
continue;
}
maxbits = getchar(); /* set -b from file */
block_compress = maxbits & BLOCK_MASK;
maxbits &= BIT_MASK;
maxmaxcode = 1 << maxbits;
if(maxbits > BITS) {
fprintf(stderr,
"%s: compressed with %d bits, can only handle %d bits\n",
*fileptr, maxbits, BITS);
continue;
}
}
/* Generate output filename */
strcpy(ofname, *fileptr);
ofname[strlen(*fileptr) - 2] = '\0'; /* Strip off .Z */
} else { /* COMPRESSION */
if (strcmp(*fileptr + strlen(*fileptr) - 2, ".Z") == 0) {
fprintf(stderr, "%s: already has .Z suffix -- no change\n",
*fileptr);
continue;
}
/* Open input file */
if ((freopen(*fileptr, "r", stdin)) == NULL) {
perror(*fileptr);
perm_stat = 1;
continue;
}
stat ( *fileptr, &statbuf );
fsize = (long) statbuf.st_size;
/*
* tune hash table size for small files -- ad hoc,
* but the sizes match earlier #defines, which
* serve as upper bounds on the number of output codes.
*/
hsize = HSIZE;
if ( fsize < (1 << 12) )
hsize = MIN ( 5003, HSIZE );
else if ( fsize < (1 << 13) )
hsize = MIN ( 9001, HSIZE );
else if ( fsize < (1 << 14) )
hsize = MIN ( 18013, HSIZE );
else if ( fsize < (1 << 15) )
hsize = MIN ( 35023, HSIZE );
else if ( fsize < 47000 )
hsize = MIN ( 50021, HSIZE );
/* Generate output filename */
strcpy(ofname, *fileptr);
strcat(ofname, ".Z");
}
/* Check for overwrite of existing file */
if (overwrite == 0 && zcat_flg == 0) {
if (stat(ofname, &statbuf) == 0) {
char response[2];
response[0] = 'n';
fprintf(stderr, "%s already exists;", ofname);
if (bgnd_flag == 0 && isatty(2)) {
fprintf(stderr, " do you wish to overwrite %s (y or n)? ",
ofname);
fflush(stderr);
read(2, response, 2);
while (response[1] != '\n') {
if (read(2, response+1, 1) < 0) { /* Ack! */
perror("stderr"); break;
}
}
}
if (response[0] != 'y') {
fprintf(stderr, "\tnot overwritten\n");
continue;
}
}
}
if(zcat_flg == 0) { /* Open output file */
if (freopen(ofname, "w", stdout) == NULL) {
perror(ofname);
perm_stat = 1;
continue;
}
precious = 0;
if(!quiet)
fprintf(stderr, "%s: ", *fileptr);
}
/* Actually do the compression/decompression */
if (do_decomp == 0) compress();
#ifndef DEBUG
else decompress();
#else
else if (debug == 0) decompress();
else printcodes();
if (verbose) dump_tab();
#endif /* DEBUG */
if(zcat_flg == 0) {
copystat(*fileptr, ofname); /* Copy stats */
precious = 1;
if((exit_stat == 1) || (!quiet))
putc('\n', stderr);
}
}
} else { /* Standard input */
if (do_decomp == 0) {
compress();
#ifdef DEBUG
if(verbose) dump_tab();
#endif /* DEBUG */
if(!quiet)
putc('\n', stderr);
} else {
/* Check the magic number */
if (nomagic == 0) {
if ((getchar()!=(magic_header[0] & 0xFF))
|| (getchar()!=(magic_header[1] & 0xFF))) {
fprintf(stderr, "stdin: not in compressed format\n");
exit(1);
}
maxbits = getchar(); /* set -b from file */
block_compress = maxbits & BLOCK_MASK;
maxbits &= BIT_MASK;
maxmaxcode = 1 << maxbits;
fsize = 100000; /* assume stdin large for USERMEM */
if(maxbits > BITS) {
fprintf(stderr,
"stdin: compressed with %d bits, can only handle %d bits\n",
maxbits, BITS);
exit(1);
}
}
#ifndef DEBUG
decompress();
#else
if (debug == 0) decompress();
else printcodes();
if (verbose) dump_tab();
#endif /* DEBUG */
}
}
exit(perm_stat ? perm_stat : exit_stat);
}
static int offset;
long int in_count = 1; /* length of input */
long int bytes_out; /* length of compressed output */
long int out_count = 0; /* # of codes output (for debugging) */
/*
* compress stdin to stdout
*
* Algorithm: use open addressing double hashing (no chaining) on the
* prefix code / next character combination. We do a variant of Knuth's
* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
* secondary probe. Here, the modular division first probe is gives way
* to a faster exclusive-or manipulation. Also do block compression with
* an adaptive reset, whereby the code table is cleared when the compression
* ratio decreases, but after the table fills. The variable-length output
* codes are re-sized at this point, and a special CLEAR code is generated
* for the decompressor. Late addition: construct the table according to
* file size for noticeable speed improvement on small files. Please direct
* questions about this implementation to ames!jaw.
*/
compress()
{
register long fcode;
register code_int i = 0;
register int c;
register code_int ent;
register int disp;
register code_int hsize_reg;
register int hshift;
#ifndef COMPATIBLE
if (nomagic == 0) {
putchar(magic_header[0]);
putchar(magic_header[1]);
putchar((char)(maxbits | block_compress));
if(ferror(stdout))
writeerr();
}
#endif /* COMPATIBLE */
offset = 0;
bytes_out = 3; /* includes 3-byte header mojo */
out_count = 0;
clear_flg = 0;
ratio = 0;
in_count = 1;
checkpoint = CHECK_GAP;
maxcode = MAXCODE(n_bits = INIT_BITS);
free_ent = ((block_compress) ? FIRST : 256 );
ent = getchar ();
hshift = 0;
for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L )
hshift++;
hshift = 8 - hshift; /* set hash code range bound */
hsize_reg = hsize;
cl_hash( (count_int) hsize_reg); /* clear hash table */
#ifdef SIGNED_COMPARE_SLOW
while ( (c = getchar()) != (unsigned) EOF ) {
#else
while ( (c = getchar()) != EOF ) {
#endif
in_count++;
fcode = (long) (((long) c << maxbits) + ent);
i = ((c << hshift) ^ ent); /* xor hashing */
if ( htabof (i) == fcode ) {
ent = codetabof (i);
continue;
} else if ( (long)htabof (i) < 0 ) /* empty slot */
goto nomatch;
disp = hsize_reg - i; /* secondary hash (after G. Knott) */
if ( i == 0 )
disp = 1;
probe:
if ( (i -= disp) < 0 )
i += hsize_reg;
if ( htabof (i) == fcode ) {
ent = codetabof (i);
continue;
}
if ( (long)htabof (i) > 0 )
goto probe;
nomatch:
output ( (code_int) ent );
out_count++;
ent = c;
#ifdef SIGNED_COMPARE_SLOW
if ( (unsigned) free_ent < (unsigned) maxmaxcode) {
#else
if ( free_ent < maxmaxcode ) {
#endif
codetabof (i) = free_ent++; /* code -> hashtable */
htabof (i) = fcode;
}
else if ( (count_int)in_count >= checkpoint && block_compress )
cl_block ();
}
/*
* Put out the final code.
*/
output( (code_int)ent );
out_count++;
output( (code_int)-1 );
/*
* Print out stats on stderr
*/
if(zcat_flg == 0 && !quiet) {
#ifdef DEBUG
fprintf( stderr,
"%ld chars in, %ld codes (%ld bytes) out, compression factor: ",
in_count, out_count, bytes_out );
prratio( stderr, in_count, bytes_out );
fprintf( stderr, "\n");
fprintf( stderr, "\tCompression as in compact: " );
prratio( stderr, in_count-bytes_out, in_count );
fprintf( stderr, "\n");
fprintf( stderr, "\tLargest code (of last block) was %d (%d bits)\n",
free_ent - 1, n_bits );
#else /* !DEBUG */
fprintf( stderr, "Compression: " );
prratio( stderr, in_count-bytes_out, in_count );
#endif /* DEBUG */
}
if(bytes_out > in_count) /* exit(2) if no savings */
exit_stat = 2;
return;
}
/*-
* Output the given code.
* Inputs:
* code: A n_bits-bit integer. If == -1, then EOF. This assumes
* that n_bits =< (long)wordsize - 1.
* Outputs:
* Outputs code to the file.
* Assumptions:
* Chars are 8 bits long.
* Algorithm:
* Maintain a BITS character long buffer (so that 8 codes will
* fit in it exactly). Use the VAX insv instruction to insert each
* code in turn. When the buffer fills up empty it and start over.
*/
static char buf[BITS];
#ifndef vax
char_type lmask[9] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
char_type rmask[9] = {0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
#endif /* vax */
output( code )
code_int code;
{
#ifdef DEBUG
static int col = 0;
#endif /* DEBUG */
/*
* On the VAX, it is important to have the register declarations
* in exactly the order given, or the asm will break.
*/
register int r_off = offset, bits= n_bits;
register char * bp = buf;
#ifdef DEBUG
if ( verbose )
fprintf( stderr, "%5d%c", code,
(col+=6) >= 74 ? (col = 0, '\n') : ' ' );
#endif /* DEBUG */
if ( code >= 0 ) {
#if defined(vax) && !defined(__GNUC__)
/*
* VAX and PCC DEPENDENT!! Implementation on other machines is
* below.
*
* Translation: Insert BITS bits from the argument starting at
* offset bits from the beginning of buf.
*/
0; /* Work around for pcc -O bug with asm and if stmt */
asm( "insv 4(ap),r11,r10,(r9)" );
#else
/*
* byte/bit numbering on the VAX is simulated by the following code
*/
/*
* Get to the first byte.
*/
bp += (r_off >> 3);
r_off &= 7;
/*
* Since code is always >= 8 bits, only need to mask the first
* hunk on the left.
*/
*bp = (*bp & rmask[r_off]) | (code << r_off) & lmask[r_off];
bp++;
bits -= (8 - r_off);
code >>= 8 - r_off;
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if ( bits >= 8 ) {
*bp++ = code;
code >>= 8;
bits -= 8;
}
/* Last bits. */
if(bits)
*bp = code;
#endif /* vax */
offset += n_bits;
if ( offset == (n_bits << 3) ) {
bp = buf;
bits = n_bits;
bytes_out += bits;
do {
putchar(*bp++);
if (ferror(stdout))
writeerr();
} while(--bits);
offset = 0;
}
/*
* If the next entry is going to be too big for the code size,
* then increase it, if possible.
*/
if ( free_ent > maxcode || (clear_flg > 0))
{
/*
* Write the whole buffer, because the input side won't
* discover the size increase until after it has read it.
*/
if ( offset > 0 ) {
if( fwrite( buf, 1, n_bits, stdout ) != n_bits)
writeerr();
bytes_out += n_bits;
}
offset = 0;
if ( clear_flg ) {
maxcode = MAXCODE (n_bits = INIT_BITS);
clear_flg = 0;
}
else {
n_bits++;
if ( n_bits == maxbits )
maxcode = maxmaxcode;
else
maxcode = MAXCODE(n_bits);
}
#ifdef DEBUG
if ( debug ) {
fprintf( stderr, "\nChange to %d bits\n", n_bits );
col = 0;
}
#endif /* DEBUG */
}
} else {
/*
* At EOF, write the rest of the buffer.
*/
if ( offset > 0 ) {
offset = (offset + 7) / 8;
if( fwrite( buf, 1, offset, stdout ) != offset )
writeerr();
bytes_out += offset;
}
offset = 0;
(void)fflush( stdout );
if( ferror( stdout ) )
writeerr();
#ifdef DEBUG
if ( verbose )
fprintf( stderr, "\n" );
#endif
}
}
/*
* Decompress stdin to stdout. This routine adapts to the codes in the
* file building the "string" table on-the-fly; requiring no table to
* be stored in the compressed file. The tables used herein are shared
* with those of the compress() routine. See the definitions above.
*/
decompress() {
register char_type *stackp;
register int finchar;
register code_int code, oldcode, incode;
int n, nwritten, offset; /* Variables for buffered write */
char buff[BUFSIZ]; /* Buffer for buffered write */
/*
* As above, initialize the first 256 entries in the table.
*/
maxcode = MAXCODE(n_bits = INIT_BITS);
for ( code = 255; code >= 0; code-- ) {
tab_prefixof(code) = 0;
tab_suffixof(code) = (char_type)code;
}
free_ent = ((block_compress) ? FIRST : 256 );
finchar = oldcode = getcode();
if(oldcode == -1) /* EOF already? */
return; /* Get out of here */
/* first code must be 8 bits = char */
n=0;
buff[n++] = (char)finchar;
stackp = de_stack;
while ( (code = getcode()) > -1 ) {
if ( (code == CLEAR) && block_compress ) {
for ( code = 255; code >= 0; code-- )
tab_prefixof(code) = 0;
clear_flg = 1;
free_ent = FIRST - 1;
if ( (code = getcode ()) == -1 ) /* O, untimely death! */
break;
}
incode = code;
/*
* Special case for KwKwK string.
*/
if ( code >= free_ent ) {
*stackp++ = finchar;
code = oldcode;
}
/*
* Generate output characters in reverse order
*/
#ifdef SIGNED_COMPARE_SLOW
while ( ((unsigned long)code) >= ((unsigned long)256) ) {
#else
while ( code >= 256 ) {
#endif
*stackp++ = tab_suffixof(code);
code = tab_prefixof(code);
}
*stackp++ = finchar = tab_suffixof(code);
/*
* And put them out in forward order
*/
do {
/*
* About 60% of the time is spent in the putchar() call
* that appeared here. It was originally
* putchar ( *--stackp );
* If we buffer the writes ourselves, we can go faster (about
* 30%).
*
* At this point, the next line is the next *big* time
* sink in the code. It takes up about 10% of the time.
*/
buff[n++] = *--stackp;
if (n == BUFSIZ) {
offset = 0;
do {
nwritten = write(fileno(stdout), &buff[offset], n);
if (nwritten < 0)
writeerr();
offset += nwritten;
} while ((n -= nwritten) > 0);
}
} while ( stackp > de_stack );
/*
* Generate the new entry.
*/
if ( (code=free_ent) < maxmaxcode ) {
tab_prefixof(code) = (unsigned short)oldcode;
tab_suffixof(code) = finchar;
free_ent = code+1;
}
/*
* Remember previous code.
*/
oldcode = incode;
}
/*
* Flush the stuff remaining in our buffer...
*/
offset = 0;
while (n > 0) {
nwritten = write(fileno(stdout), &buff[offset], n);
if (nwritten < 0)
writeerr();
offset += nwritten;
n -= nwritten;
}
}
/*-
* Read one code from the standard input. If EOF, return -1.
* Inputs:
* stdin
* Outputs:
* code or -1 is returned.
*/
code_int
getcode() {
/*
* On the VAX, it is important to have the register declarations
* in exactly the order given, or the asm will break.
*/
register code_int code;
static int offset = 0, size = 0;
static char_type buf[BITS];
register int r_off, bits;
register char_type *bp = buf;
if ( clear_flg > 0 || offset >= size || free_ent > maxcode ) {
/*
* If the next entry will be too big for the current code
* size, then we must increase the size. This implies reading
* a new buffer full, too.
*/
if ( free_ent > maxcode ) {
n_bits++;
if ( n_bits == maxbits )
maxcode = maxmaxcode; /* won't get any bigger now */
else
maxcode = MAXCODE(n_bits);
}
if ( clear_flg > 0) {
maxcode = MAXCODE (n_bits = INIT_BITS);
clear_flg = 0;
}
size = fread( buf, 1, n_bits, stdin );
if ( size <= 0 )
return -1; /* end of file */
offset = 0;
/* Round size down to integral number of codes */
size = (size << 3) - (n_bits - 1);
}
r_off = offset;
bits = n_bits;
#ifdef vax
asm( "extzv r10,r9,(r8),r11" );
#else /* not a vax */
/*
* Get to the first byte.
*/
bp += (r_off >> 3);
r_off &= 7;
/* Get first part (low order bits) */
#ifdef NO_UCHAR
code = ((*bp++ >> r_off) & rmask[8 - r_off]) & 0xff;
#else
code = (*bp++ >> r_off);
#endif /* NO_UCHAR */
bits -= (8 - r_off);
r_off = 8 - r_off; /* now, offset into code word */
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
if ( bits >= 8 ) {
#ifdef NO_UCHAR
code |= (*bp++ & 0xff) << r_off;
#else
code |= *bp++ << r_off;
#endif /* NO_UCHAR */
r_off += 8;
bits -= 8;
}
/* high order bits. */
code |= (*bp & rmask[bits]) << r_off;
#endif /* vax */
offset += n_bits;
return code;
}
#ifdef DEBUG
printcodes()
{
/*
* Just print out codes from input file. For debugging.
*/
code_int code;
int col = 0, bits;
bits = n_bits = INIT_BITS;
maxcode = MAXCODE(n_bits);
free_ent = ((block_compress) ? FIRST : 256 );
while ( ( code = getcode() ) >= 0 ) {
if ( (code == CLEAR) && block_compress ) {
free_ent = FIRST - 1;
clear_flg = 1;
}
else if ( free_ent < maxmaxcode )
free_ent++;
if ( bits != n_bits ) {
fprintf(stderr, "\nChange to %d bits\n", n_bits );
bits = n_bits;
col = 0;
}
fprintf(stderr, "%5d%c", code, (col+=6) >= 74 ? (col = 0, '\n') : ' ' );
}
putc( '\n', stderr );
exit( 0 );
}
code_int sorttab[1<<BITS]; /* sorted pointers into htab */
dump_tab() /* dump string table */
{
register int i, first;
register ent;
#define STACK_SIZE 15000
int stack_top = STACK_SIZE;
register c;
if(do_decomp == 0) { /* compressing */
register int flag = 1;
for(i=0; i<hsize; i++) { /* build sort pointers */
if((long)htabof(i) >= 0) {
sorttab[codetabof(i)] = i;
}
}
first = block_compress ? FIRST : 256;
for(i = first; i < free_ent; i++) {
fprintf(stderr, "%5d: \"", i);
de_stack[--stack_top] = '\n';
de_stack[--stack_top] = '"';
stack_top = in_stack((htabof(sorttab[i])>>maxbits)&0xff,
stack_top);
for(ent=htabof(sorttab[i]) & ((1<<maxbits)-1);
ent > 256;
ent=htabof(sorttab[ent]) & ((1<<maxbits)-1)) {
stack_top = in_stack(htabof(sorttab[ent]) >> maxbits,
stack_top);
}
stack_top = in_stack(ent, stack_top);
fwrite( &de_stack[stack_top], 1, STACK_SIZE-stack_top, stderr);
stack_top = STACK_SIZE;
}
} else if(!debug) { /* decompressing */
for ( i = 0; i < free_ent; i++ ) {
ent = i;
c = tab_suffixof(ent);
if ( isascii(c) && isprint(c) )
fprintf( stderr, "%5d: %5d/'%c' \"",
ent, tab_prefixof(ent), c );
else
fprintf( stderr, "%5d: %5d/\\%03o \"",
ent, tab_prefixof(ent), c );
de_stack[--stack_top] = '\n';
de_stack[--stack_top] = '"';
for ( ; ent != NULL;
ent = (ent >= FIRST ? tab_prefixof(ent) : NULL) ) {
stack_top = in_stack(tab_suffixof(ent), stack_top);
}
fwrite( &de_stack[stack_top], 1, STACK_SIZE - stack_top, stderr );
stack_top = STACK_SIZE;
}
}
}
int
in_stack(c, stack_top)
register c, stack_top;
{
if ( (isascii(c) && isprint(c) && c != '\\') || c == ' ' ) {
de_stack[--stack_top] = c;
} else {
switch( c ) {
case '\n': de_stack[--stack_top] = 'n'; break;
case '\t': de_stack[--stack_top] = 't'; break;
case '\b': de_stack[--stack_top] = 'b'; break;
case '\f': de_stack[--stack_top] = 'f'; break;
case '\r': de_stack[--stack_top] = 'r'; break;
case '\\': de_stack[--stack_top] = '\\'; break;
default:
de_stack[--stack_top] = '0' + c % 8;
de_stack[--stack_top] = '0' + (c / 8) % 8;
de_stack[--stack_top] = '0' + c / 64;
break;
}
de_stack[--stack_top] = '\\';
}
return stack_top;
}
#endif /* DEBUG */
writeerr()
{
(void)fprintf(stderr, "compress: %s: %s\n",
ofname[0] ? ofname : "stdout", strerror(errno));
(void)unlink(ofname);
exit(1);
}
copystat(ifname, ofname)
char *ifname, *ofname;
{
struct stat statbuf;
int mode;
struct utimbuf tp;
fclose(stdout);
if (stat(ifname, &statbuf)) { /* Get stat on input file */
perror(ifname);
return;
}
if ((statbuf.st_mode & S_IFMT/*0170000*/) != S_IFREG/*0100000*/) {
if(quiet)
fprintf(stderr, "%s: ", ifname);
fprintf(stderr, " -- not a regular file: unchanged");
exit_stat = 1;
perm_stat = 1;
} else if (statbuf.st_nlink > 1) {
if(quiet)
fprintf(stderr, "%s: ", ifname);
fprintf(stderr, " -- has %d other links: unchanged",
statbuf.st_nlink - 1);
exit_stat = 1;
perm_stat = 1;
} else if (exit_stat == 2 && (!force)) { /* No compression: remove file.Z */
if(!quiet)
fprintf(stderr, " -- file unchanged");
} else { /* ***** Successful Compression ***** */
exit_stat = 0;
mode = statbuf.st_mode & 07777;
if (chmod(ofname, mode)) /* Copy modes */
perror(ofname);
chown(ofname, statbuf.st_uid, statbuf.st_gid); /* Copy ownership */
tp.actime = statbuf.st_atime;
tp.modtime = statbuf.st_mtime;
utime(ofname, &tp); /* Update last accessed and modified times */
if (unlink(ifname)) /* Remove input file */
perror(ifname);
if(!quiet)
fprintf(stderr, " -- replaced with %s", ofname);
return; /* Successful return */
}
/* Unsuccessful return -- one of the tests failed */
if (unlink(ofname))
perror(ofname);
}
void
onintr ( )
{
if (!precious)
unlink ( ofname );
exit ( 1 );
}
void
oops ( ) /* wild pointer -- assume bad input */
{
if ( do_decomp )
fprintf ( stderr, "uncompress: corrupt input\n" );
unlink ( ofname );
exit ( 1 );
}
cl_block () /* table clear for block compress */
{
register long int rat;
checkpoint = in_count + CHECK_GAP;
#ifdef DEBUG
if ( debug ) {
fprintf ( stderr, "count: %ld, ratio: ", in_count );
prratio ( stderr, in_count, bytes_out );
fprintf ( stderr, "\n");
}
#endif /* DEBUG */
if(in_count > 0x007fffff) { /* shift will overflow */
rat = bytes_out >> 8;
if(rat == 0) { /* Don't divide by zero */
rat = 0x7fffffff;
} else {
rat = in_count / rat;
}
} else {
rat = (in_count << 8) / bytes_out; /* 8 fractional bits */
}
if ( rat > ratio ) {
ratio = rat;
} else {
ratio = 0;
#ifdef DEBUG
if(verbose)
dump_tab(); /* dump string table */
#endif
cl_hash ( (count_int) hsize );
free_ent = FIRST;
clear_flg = 1;
output ( (code_int) CLEAR );
#ifdef DEBUG
if(debug)
fprintf ( stderr, "clear\n" );
#endif /* DEBUG */
}
}
cl_hash(hsize) /* reset code table */
register count_int hsize;
{
register count_int *htab_p = htab+hsize;
register long i;
register long m1 = -1;
i = hsize - 16;
do { /* might use Sys V memset(3) here */
*(htab_p-16) = m1;
*(htab_p-15) = m1;
*(htab_p-14) = m1;
*(htab_p-13) = m1;
*(htab_p-12) = m1;
*(htab_p-11) = m1;
*(htab_p-10) = m1;
*(htab_p-9) = m1;
*(htab_p-8) = m1;
*(htab_p-7) = m1;
*(htab_p-6) = m1;
*(htab_p-5) = m1;
*(htab_p-4) = m1;
*(htab_p-3) = m1;
*(htab_p-2) = m1;
*(htab_p-1) = m1;
htab_p -= 16;
} while ((i -= 16) >= 0);
for ( i += 16; i > 0; i-- )
*--htab_p = m1;
}
prratio(stream, num, den)
FILE *stream;
long int num, den;
{
register int q; /* Doesn't need to be long */
if(num > 214748L) { /* 2147483647/10000 */
q = num / (den / 10000L);
} else {
q = 10000L * num / den; /* Long calculations, though */
}
if (q < 0) {
putc('-', stream);
q = -q;
}
fprintf(stream, "%d.%02d%%", q / 100, q % 100);
}
usage()
{
(void)fprintf(stderr,
#ifdef DEBUG
"compress [-CDVcdfnv] [-b maxbits] [file ...]\n");
#else
"compress [-Ccdfnv] [-b maxbits] [file ...]\n");
#endif
exit(1);
}