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-Thread: 103376,4fbd260da735f6f4 X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.com!out02b.usenetserver.com!news.usenetserver.com!in04.usenetserver.com!news.usenetserver.com!nx01.iad01.newshosting.com!newshosting.com!204.127.204.224.MISMATCH!wns14feed!worldnet.att.net!199.45.49.37!cyclone1.gnilink.net!spamkiller.gnilink.net!gnilink.net!trnddc03.POSTED!72fcb693!not-for-mail From: Fionn Mac Cumhaill Newsgroups: comp.lang.ada Subject: Re: Reading and writing a big file in Ada (GNAT) on Windows XP Message-ID: References: <0hj5339mjmond132qhbn2o01unurs61lbj@4ax.com> X-Newsreader: Forte Agent 4.2/32.1117 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Sun, 29 Apr 2007 21:46:29 GMT NNTP-Posting-Host: 71.170.31.60 X-Complaints-To: abuse@verizon.net X-Trace: trnddc03 1177883189 71.170.31.60 (Sun, 29 Apr 2007 17:46:29 EDT) NNTP-Posting-Date: Sun, 29 Apr 2007 17:46:29 EDT Xref: g2news1.google.com comp.lang.ada:15405 Date: 2007-04-29T21:46:29+00:00 List-Id: On Sat, 28 Apr 2007 19:12:33 GMT, "Jeffrey R. Carter" wrote: >Fionn Mac Cumhaill wrote: >> >> All it does is read lines in a loop from a text file with >> Ada.Text_IO.Get_Line, does minor modifications on about 80% of the >> lines that it reads, and writes the lines to an output file with >> Put_Line. >> >> The modifications consist of replacing a slice of text at the end of a >> line with another bit of text. The biggest slice is 10 characters, and >> the replacement slice is always smaller than the original slice. An >> occasional line of text is about 6000 characters long, but most are >> about 700 haracters. Get_Line reads them into a String variable that >> is 10,000 characters long. >> >> The problem is that the input file has more than 10 million lines of >> text in it. The program works perfectly, but takes about 5 hours to >> run. The Cygwin version of wc can count the lines in the input file in >> less than one minute. >> >> Why is this so slow? >> Do I have an Ada problem, a GNAT problem, or a MinGW problem? > >It's hard to tell. Text_IO is quite heavy-weight compared to C text I/O, >but I'd be surprised if it made that much difference. > >This sounds as if it would be a pretty simple program; if so, you could >post it (or a reasonable facsimile, if there's a reason you can't post >the actual code) here, and we would be better able to help. I'm posting to cla from home. The program is at work. I'll post the code when I get back to work.