xref: /dflybsd-src/usr.bin/compress/doc/revision.log (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
186d7f5d3SJohn Marino/* $FreeBSD: src/usr.bin/compress/doc/revision.log,v 1.3.2.1 2002/07/16 00:42:48 tjr Exp $ */
286d7f5d3SJohn Marino/* $DragonFly: src/usr.bin/compress/doc/revision.log,v 1.2 2003/06/17 04:29:25 dillon Exp $ */
386d7f5d3SJohn Marino
486d7f5d3SJohn Marino/*
586d7f5d3SJohn Marino * $Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $
686d7f5d3SJohn Marino * $Log:	compress.c,v $
786d7f5d3SJohn Marino * Revision 4.0  85/07/30  12:50:00  joe
886d7f5d3SJohn Marino * Removed ferror() calls in output routine on every output except first.
986d7f5d3SJohn Marino * Prepared for release to the world.
1086d7f5d3SJohn Marino *
1186d7f5d3SJohn Marino * Revision 3.6  85/07/04  01:22:21  joe
1286d7f5d3SJohn Marino * Remove much wasted storage by overlaying hash table with the tables
1386d7f5d3SJohn Marino * used by decompress: tab_suffix[1<<BITS], stack[8000].  Updated USERMEM
1486d7f5d3SJohn Marino * computations.  Fixed dump_tab() DEBUG routine.
1586d7f5d3SJohn Marino *
1686d7f5d3SJohn Marino * Revision 3.5  85/06/30  20:47:21  jaw
1786d7f5d3SJohn Marino * Change hash function to use exclusive-or.  Rip out hash cache.  These
1886d7f5d3SJohn Marino * speedups render the megamemory version defunct, for now.  Make decoder
1986d7f5d3SJohn Marino * stack global.  Parts of the RCS trunks 2.7, 2.6, and 2.1 no longer apply.
2086d7f5d3SJohn Marino *
2186d7f5d3SJohn Marino * Revision 3.4  85/06/27  12:00:00  ken
2286d7f5d3SJohn Marino * Get rid of all floating-point calculations by doing all compression ratio
2386d7f5d3SJohn Marino * calculations in fixed point.
2486d7f5d3SJohn Marino *
2586d7f5d3SJohn Marino * Revision 3.3  85/06/24  21:53:24  joe
2686d7f5d3SJohn Marino * Incorporate portability suggestion for M_XENIX.  Got rid of text on #else
2786d7f5d3SJohn Marino * and #endif lines.  Cleaned up #ifdefs for vax and interdata.
2886d7f5d3SJohn Marino *
2986d7f5d3SJohn Marino * Revision 3.2  85/06/06  21:53:24  jaw
3086d7f5d3SJohn Marino * Incorporate portability suggestions for Z8000, IBM PC/XT from mailing list.
3186d7f5d3SJohn Marino * Default to "quiet" output (no compression statistics).
3286d7f5d3SJohn Marino *
3386d7f5d3SJohn Marino * Revision 3.1  85/05/12  18:56:13  jaw
3486d7f5d3SJohn Marino * Integrate decompress() stack speedups (from early pointer mods by McKie).
3586d7f5d3SJohn Marino * Repair multi-file USERMEM gaffe.  Unify 'force' flags to mimic semantics
3686d7f5d3SJohn Marino * of SVR2 'pack'.  Streamline block-compress table clear logic.  Increase
3786d7f5d3SJohn Marino * output byte count by magic number size.
3886d7f5d3SJohn Marino *
3986d7f5d3SJohn Marino * Revision 3.0   84/11/27  11:50:00  petsd!joe
4086d7f5d3SJohn Marino * Set HSIZE depending on BITS.  Set BITS depending on USERMEM.  Unrolled
4186d7f5d3SJohn Marino * loops in clear routines.  Added "-C" flag for 2.0 compatibility.  Used
4286d7f5d3SJohn Marino * unsigned compares on Perkin-Elmer.  Fixed foreground check.
4386d7f5d3SJohn Marino *
4486d7f5d3SJohn Marino * Revision 2.7   84/11/16  19:35:39  ames!jaw
4586d7f5d3SJohn Marino * Cache common hash codes based on input statistics; this improves
4686d7f5d3SJohn Marino * performance for low-density raster images.  Pass on #ifdef bundle
4786d7f5d3SJohn Marino * from Turkowski.
4886d7f5d3SJohn Marino *
4986d7f5d3SJohn Marino * Revision 2.6   84/11/05  19:18:21  ames!jaw
5086d7f5d3SJohn Marino * Vary size of hash tables to reduce time for small files.
5186d7f5d3SJohn Marino * Tune PDP-11 hash function.
5286d7f5d3SJohn Marino *
5386d7f5d3SJohn Marino * Revision 2.5   84/10/30  20:15:14  ames!jaw
5486d7f5d3SJohn Marino * Junk chaining; replace with the simpler (and, on the VAX, faster)
5586d7f5d3SJohn Marino * double hashing, discussed within.  Make block compression standard.
5686d7f5d3SJohn Marino *
5786d7f5d3SJohn Marino * Revision 2.4   84/10/16  11:11:11  ames!jaw
5886d7f5d3SJohn Marino * Introduce adaptive reset for block compression, to boost the rate
5986d7f5d3SJohn Marino * another several percent.  (See mailing list notes.)
6086d7f5d3SJohn Marino *
6186d7f5d3SJohn Marino * Revision 2.3   84/09/22  22:00:00  petsd!joe
6286d7f5d3SJohn Marino * Implemented "-B" block compress.  Implemented REVERSE sorting of tab_next.
6386d7f5d3SJohn Marino * Bug fix for last bits.  Changed fwrite to putchar loop everywhere.
6486d7f5d3SJohn Marino *
6586d7f5d3SJohn Marino * Revision 2.2   84/09/18  14:12:21  ames!jaw
6686d7f5d3SJohn Marino * Fold in news changes, small machine typedef from thomas,
6786d7f5d3SJohn Marino * #ifdef interdata from joe.
6886d7f5d3SJohn Marino *
6986d7f5d3SJohn Marino * Revision 2.1   84/09/10  12:34:56  ames!jaw
7086d7f5d3SJohn Marino * Configured fast table lookup for 32-bit machines.
7186d7f5d3SJohn Marino * This cuts user time in half for b <= FBITS, and is useful for news batching
7286d7f5d3SJohn Marino * from VAX to PDP sites.  Also sped up decompress() [fwrite->putc] and
7386d7f5d3SJohn Marino * added signal catcher [plus beef in writeerr()] to delete effluvia.
7486d7f5d3SJohn Marino *
7586d7f5d3SJohn Marino * Revision 2.0   84/08/28  22:00:00  petsd!joe
7686d7f5d3SJohn Marino * Add check for foreground before prompting user.  Insert maxbits into
7786d7f5d3SJohn Marino * compressed file.  Force file being uncompressed to end with ".Z".
7886d7f5d3SJohn Marino * Added "-c" flag and "zcat".  Prepared for release.
7986d7f5d3SJohn Marino *
8086d7f5d3SJohn Marino * Revision 1.10  84/08/24  18:28:00  turtlevax!ken
8186d7f5d3SJohn Marino * Will only compress regular files (no directories), added a magic number
8286d7f5d3SJohn Marino * header (plus an undocumented -n flag to handle old files without headers),
8386d7f5d3SJohn Marino * added -f flag to force overwriting of possibly existing destination file,
8486d7f5d3SJohn Marino * otherwise the user is prompted for a response.  Will tack on a .Z to a
8586d7f5d3SJohn Marino * filename if it doesn't have one when decompressing.  Will only replace
8686d7f5d3SJohn Marino * file if it was compressed.
8786d7f5d3SJohn Marino *
8886d7f5d3SJohn Marino * Revision 1.9  84/08/16  17:28:00  turtlevax!ken
8986d7f5d3SJohn Marino * Removed scanargs(), getopt(), added .Z extension and unlimited number of
9086d7f5d3SJohn Marino * filenames to compress.  Flags may be clustered (-Ddvb12) or separated
9186d7f5d3SJohn Marino * (-D -d -v -b 12), or combination thereof.  Modes and other status is
9286d7f5d3SJohn Marino * copied with copystat().  -O bug for 4.2 seems to have disappeared with
9386d7f5d3SJohn Marino * 1.8.
9486d7f5d3SJohn Marino *
9586d7f5d3SJohn Marino * Revision 1.8  84/08/09  23:15:00  joe
9686d7f5d3SJohn Marino * Made it compatible with vax version, installed jim's fixes/enhancements
9786d7f5d3SJohn Marino *
9886d7f5d3SJohn Marino * Revision 1.6  84/08/01  22:08:00  joe
9986d7f5d3SJohn Marino * Sped up algorithm significantly by sorting the compress chain.
10086d7f5d3SJohn Marino *
10186d7f5d3SJohn Marino * Revision 1.5  84/07/13  13:11:00  srd
10286d7f5d3SJohn Marino * Added C version of vax asm routines.  Changed structure to arrays to
10386d7f5d3SJohn Marino * save much memory.  Do unsigned compares where possible (faster on
10486d7f5d3SJohn Marino * Perkin-Elmer)
10586d7f5d3SJohn Marino *
10686d7f5d3SJohn Marino * Revision 1.4  84/07/05  03:11:11  thomas
10786d7f5d3SJohn Marino * Clean up the code a little and lint it.  (Lint complains about all
10886d7f5d3SJohn Marino * the regs used in the asm, but I'm not going to "fix" this.)
10986d7f5d3SJohn Marino *
11086d7f5d3SJohn Marino * Revision 1.3  84/07/05  02:06:54  thomas
11186d7f5d3SJohn Marino * Minor fixes.
11286d7f5d3SJohn Marino *
11386d7f5d3SJohn Marino * Revision 1.2  84/07/05  00:27:27  thomas
11486d7f5d3SJohn Marino * Add variable bit length output.
11586d7f5d3SJohn Marino *
11686d7f5d3SJohn Marino */
11786d7f5d3SJohn Marino
11886d7f5d3SJohn Marinostatic char rcs_ident[] =
11986d7f5d3SJohn Marino	"$Header: compress.c,v 4.0 85/07/30 12:50:00 joe Release $";
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