Re: Reading and writing a big file in Ada (GNAT) on Windows XP

[Fionn Mac Cumhaill <invisible@hiding.from.spam>]

On Sat, 28 Apr 2007 18:56:47 +0100, Simon Wright
<simon.j.wright@mac.com> wrote:

>Fionn Mac Cumhaill <invisible@hiding.from.spam> writes:
>
>> 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.
>
>Yesterday I found a performance (and stack!) related problem in GNAT's
>Ada.Strings.Fixed.Index. The string is mapped onto the stack before
>the search is done. But I wouldn't have thought this would result in a
>5 hour run time. How do you decide which lines need conversion?

I use Index to search for the string that needs to be replaced. if the
returned value is not zero, that line needs to be changed. In 99.99%
of the changes, I look for ", ''),"  and replace it with "),"