From sco!karll Mon Jul 22 18:05:51 1991 Received: by One.NeoSoft.Com (smail2.5) id AA00757; 22 Jul 91 18:05:50 PDT (Mon) Received: from marisco.sco.COM by sco.sco.COM id aa13967; Mon, 22 Jul 91 17:37:52 PDT From: Karl Lehenbauer X-Mailer: SCO System V Mail (version 3.2) To: karl@one.neosoft.COM Subject: zoo speedup Date: Mon, 22 Jul 91 17:37:01 PDT Message-ID: <9107221737.aa06379@marisco.sco.COM> Status: O Relay-Version: B 2.11 6/12/87; site scolex Path: uunet!uunet!zaphod.mps.ohio-state.edu!usc!apple!motcsd!dms!rains From: rains@dms.UUCP (Lyle Rains) Newsgroups: comp.compression Subject: Faster zoo 2.1 for UNIX Keywords: zoo Message-ID: <1269@dms.UUCP> Date: Fri, 19 Jul 91 17:30:22 PDT Organization: Atari Games Inc., Milpitas, CA Lines: 45 In looking at the difference in speed between zoo 2.01 and zoo 2.10 on my SysV386 system (ESIX 3.2D), I noticed that the user and system times appeared similar, but the elapsed time was 40% greater for the new zoo. This smelled like an I/O problem, so I tried increasing the input buffer size in "zoomem.h" from 8k to 32k (I also modified the MEM_BLOCK_SIZE #define to match the change) as follows: ---------- CUT HERE --------- /*************************************************************/ /* DO NOT CHANGE THE REST OF THIS FILE. */ /*************************************************************/ /* ** I noted this and cautiously proceeded with the change anyway :-). -LVR */ /* The main I/O buffer (called in_buf_adr in zoo.c) is reused in several places. */ #define IN_BUF_SIZE 0x8000 #define OUT_BUF_SIZE 0x2000 /* MEM_BLOCK_SIZE must be no less than (2 * DICSIZ + MAXMATCH) (see ar.h and lzh.h for values). The buffer of this size will also hold an input buffer of IN_BUF_SIZE and an output buffer of OUT_BUF_SIZE. FUDGE is a fudge factor, to keep some spare and avoid off-by-one errors. */ #define FUDGE 8 #define MEM_BLOCK_SIZE (IN_BUF_SIZE + OUT_BUF_SIZE + FUDGE) ------ END CUT ------- The result was that zoo 2.10 elapsed times decreased to that of version 2.01 for the original LZW compression. -- wmm -/@-@\- Lyle Rains <-- motcsd!dms!rains or lrains@netcom.com ( (_) ) Atari Games <-- "Tube hits for two-bits" \_o_/ Milpitas, CA <-- With convenient parking in lots 237 and 880.