From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,1769ac558c6fa259 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-02-21 16:00:06 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!news.gtei.net!newscon02.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!postmaster.news.prodigy.com!newssvr14.news.prodigy.com.POSTED!not-for-mail From: tmoran@acm.org Newsgroups: comp.lang.ada Subject: Re: How to speed up stream & record handling? References: <87it8qeg4q.fsf@deneb.enyo.de> X-Newsreader: Tom's custom newsreader Message-ID: <8Rfd8.41459$Cu.776895529@newssvr14.news.prodigy.com> NNTP-Posting-Host: 64.175.243.17 X-Complaints-To: abuse@prodigy.net X-Trace: newssvr14.news.prodigy.com 1014335940 ST000 64.175.243.17 (Thu, 21 Feb 2002 18:59:00 EST) NNTP-Posting-Date: Thu, 21 Feb 2002 18:59:00 EST Organization: Prodigy Internet http://www.prodigy.com X-UserInfo1: Q[RGGTSDZRRQBQH]]RKB_UDAZZ\DPCPDLXUNNHXIJYWZUYICD^RAQBKZQTZTX\_I[^G_KGFNON[ZOE_AZNVO^\XGGNTCIRPIJH[@RQKBXLRZ@CD^HKANYVW@RLGEZEJN@\_WZJBNZYYKVIOR]T]MNMG_Z[YVWSCH_Q[GPC_A@CARQVXDSDA^M]@DRVUM@RBM Date: Thu, 21 Feb 2002 23:59:00 GMT Xref: archiver1.google.com comp.lang.ada:20234 Date: 2002-02-21T23:59:00+00:00 List-Id: > Data_array'Read (and thus My_Record'Read) calls Unsigned_8'Read for > each array element individually. Perhaps this burns a lot of CPU I suspect you're right. I ran the program as given on a 750MHz Windows system and it took 7.7 seconds. It runs in .13 seconds with some simple changes: type My_Record is record A : Data_array; -- 200 bytes -- BC : B_And_C; -- 2 bytes BC : Byte_Array(1 .. 2); end record; buffer : my_record; package bio is new ada.sequential_io(my_record); ... for I in 1 .. 100000 loop bio.read(f,buffer); swap(buffer.bc); end loop;