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Atari Mega Archive 1
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ncmp424s.zoo
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compress42.c
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C/C++ Source or Header
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1993-03-06
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49KB
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1,946 lines
/* (N)compress42.c - File compression ala IEEE Computer, Mar 1992.
*
* Authors:
* Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!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)
* Dave Mack (csu@alembic.acs.com)
* Peter Jannesen, Network Communication Systems
* (peter@ncs.nl)
*
* Revision 4.2.3 92/03/14 peter@ncs.nl
* Optimise compress and decompress function and a lot of cleanups.
* New fast hash algoritme added (if more than 800Kb available).
*
* Revision 4.1 91/05/26 csu@alembic.acs.com
* Modified to recursively compress directories ('r' flag). As a side
* effect, compress will no longer attempt to compress things that
* aren't "regular" files. See Changes.
*
* Revision 4.0 85/07/30 12:50:00 joe
* Removed ferror() calls in output routine on every output except first.
* Prepared for release to the world.
*
* Revision 3.6 85/07/04 01:22:21 joe
* Remove much wasted storage by overlaying hash table with the tables
* used by decompress: tab_suffix[1<<BITS], stack[8000]. Updated USERMEM
* computations. Fixed dump_tab() DEBUG routine.
*
* Revision 3.5 85/06/30 20:47:21 jaw
* Change hash function to use exclusive-or. Rip out hash cache. These
* speedups render the megamemory version defunct, for now. Make decoder
* stack global. Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply.
*
* Revision 3.4 85/06/27 12:00:00 ken
* Get rid of all floating-point calculations by doing all compression ratio
* calculations in fixed point.
*
* Revision 3.3 85/06/24 21:53:24 joe
* Incorporate portability suggestion for M_XENIX. Got rid of text on #else
* and #endif lines. Cleaned up #ifdefs for vax and interdata.
*
* Revision 3.2 85/06/06 21:53:24 jaw
* Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list.
* Default to "quiet" output (no compression statistics).
*
* Revision 3.1 85/05/12 18:56:13 jaw
* Integrate decompress() stack speedups (from early pointer mods by McKie).
* Repair multi-file USERMEM gaffe. Unify 'force' flags to mimic semantics
* of SVR2 'pack'. Streamline block-compress table clear logic. Increase
* output byte count by magic number size.
*
* Revision 3.0 84/11/27 11:50:00 petsd!joe
* Set HSIZE depending on BITS. Set BITS depending on USERMEM. Unrolled
* loops in clear routines. Added "-C" flag for 2.0 compatibility. Used
* unsigned compares on Perkin-Elmer. Fixed foreground check.
*
* Revision 2.7 84/11/16 19:35:39 ames!jaw
* Cache common hash codes based on input statistics; this improves
* performance for low-density raster images. Pass on #ifdef bundle
* from Turkowski.
*
* Revision 2.6 84/11/05 19:18:21 ames!jaw
* Vary size of hash tables to reduce time for small files.
* Tune PDP-11 hash function.
*
* Revision 2.5 84/10/30 20:15:14 ames!jaw
* Junk chaining; replace with the simpler (and, on the VAX, faster)
* double hashing, discussed within. Make block compression standard.
*
* Revision 2.4 84/10/16 11:11:11 ames!jaw
* Introduce adaptive reset for block compression, to boost the rate
* another several percent. (See mailing list notes.)
*
* Revision 2.3 84/09/22 22:00:00 petsd!joe
* Implemented "-B" block compress. Implemented REVERSE sorting of tab_next.
* Bug fix for last bits. Changed fwrite to putchar loop everywhere.
*
* Revision 2.2 84/09/18 14:12:21 ames!jaw
* Fold in news changes, small machine typedef from thomas,
* #ifdef interdata from joe.
*
* Revision 2.1 84/09/10 12:34:56 ames!jaw
* Configured fast table lookup for 32-bit machines.
* This cuts user time in half for b <= FBITS, and is useful for news batching
* from VAX to PDP sites. Also sped up decompress() [fwrite->putc] and
* added signal catcher [plus beef in write_error()] to delete effluvia.
*
* Revision 2.0 84/08/28 22:00:00 petsd!joe
* Add check for foreground before prompting user. Insert maxbits into
* compressed file. Force file being uncompressed to end with ".Z".
* Added "-c" flag and "zcat". Prepared for release.
*
* Revision 1.10 84/08/24 18:28:00 turtlevax!ken
* Will only compress regular files (no directories), added a magic number
* header (plus an undocumented -n flag to handle old files without headers),
* added -f flag to force overwriting of possibly existing destination file,
* otherwise the user is prompted for a response. Will tack on a .Z to a
* filename if it doesn't have one when decompressing. Will only replace
* file if it was compressed.
*
* Revision 1.9 84/08/16 17:28:00 turtlevax!ken
* Removed scanargs(), getopt(), added .Z extension and unlimited number of
* filenames to compress. Flags may be clustered (-Ddvb12) or separated
* (-D -d -v -b 12), or combination thereof. Modes and other status is
* copied with copystat(). -O bug for 4.2 seems to have disappeared with
* 1.8.
*
* Revision 1.8 84/08/09 23:15:00 joe
* Made it compatible with vax version, installed jim's fixes/enhancements
*
* Revision 1.6 84/08/01 22:08:00 joe
* Sped up algorithm significantly by sorting the compress chain.
*
* Revision 1.5 84/07/13 13:11:00 srd
* Added C version of vax asm routines. Changed structure to arrays to
* save much memory. Do unsigned compares where possible (faster on
* Perkin-Elmer)
*
* Revision 1.4 84/07/05 03:11:11 thomas
* Clean up the code a little and lint it. (Lint complains about all
* the regs used in the asm, but I'm not going to "fix" this.)
*
* Revision 1.3 84/07/05 02:06:54 thomas
* Minor fixes.
*
* Revision 1.2 84/07/05 00:27:27 thomas
* Add variable bit length output.
*
*/
#include <stdio.h>
#include <fcntl.h>
#include <ctype.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#ifdef DIRENT
# include <dirent.h>
# define RECURSIVE 1
# undef SYSDIR
#endif
#ifdef SYSDIR
# include <sys/dir.h>
# define RECURSIVE 1
#endif
#ifdef UTIME_H
# include <utime.h>
#else
struct utimbuf {
time_t actime;
time_t modtime;
};
#endif
#ifdef __STDC__
# define ARGS(a) a
#else
# define ARGS(a) ()
#endif
#define LARGS(a) () /* Relay on include files for libary func defs. */
#ifndef SIG_TYPE
# define SIG_TYPE void (*)()
#endif
#ifndef NOFUNCDEF
extern void *malloc LARGS((int));
extern void free LARGS((void *));
#ifndef _IBMR2
extern int open LARGS((char const *,int,...));
#endif
extern int close LARGS((int));
extern int read LARGS((int,void *,int));
extern int write LARGS((int,void const *,int));
extern int chmod LARGS((char const *,int));
extern int unlink LARGS((char const *));
extern int chown LARGS((char const *,int,int));
extern int utime LARGS((char const *,struct utimbuf const *));
extern char *strcpy LARGS((char *,char const *));
extern char *strcat LARGS((char *,char const *));
extern int strcmp LARGS((char const *,char const *));
extern unsigned strlen LARGS((char const *));
extern void *memset LARGS((void *,char,unsigned int));
extern void *memcpy LARGS((void *,void const *,unsigned int));
extern int atoi LARGS((char const *));
extern void exit LARGS((int));
extern int isatty LARGS((int));
#endif
#define MARK(a) { asm(" .globl M.a"); asm("M.a:"); }
#ifdef DEF_ERRNO
extern int errno;
#endif
#include "patchlevel.h"
#undef min
#define min(a,b) ((a>b) ? b : a)
#ifndef IBUFSIZ
# define IBUFSIZ BUFSIZ /* Defailt input buffer size */
#endif
#ifndef OBUFSIZ
# define OBUFSIZ BUFSIZ /* Default output buffer size */
#endif
#define MAXPATHLEN 1024 /* MAXPATHLEN - maximum length of a pathname we allow */
#define SIZE_INNER_LOOP 256 /* Size of the inter (fast) compress loop */
/* Defines for third byte of header */
#define MAGIC_1 (char_type)'\037'/* First byte of compressed file */
#def