TomohitoNakayama wrote:
Hello.
I have one question ...
I looked at the patch briefly, and had one minor comment. In
convertToAsciiByteArray, it might be better performance wise, if we
calculate the original.length only once and use it in the for loop.
Can it be improvement of performance so much ?
Length of String object cannot be changed and there would be very less
performance improvement .
//Improvement would be just saving time of calling method .
I think it is cheaper to store the int value, rather than calling the
method N times. I did a simple test just to get some numbers with using
the length() versus calculating once. Note- this test doesnt make much
sense otherwise..
string length = 810023
test calls method length() each time = 140 ms
test precomputes length and uses the stored length = 90ms.
ex.
for(int j= 0; j < len; j++)
{
if (sb1.charAt(j) == 'a')
{
c = sb1.charAt(j);
}
}
versus, computing the length() each time.
---------------
Java^TM Performance Tuning and Java Optimization Tips :
ftp://ftp.glenmccl.com/pub/free/jperf.pdf : check out section 4.5.where
the author mentions some timing details, although the example code is
not right. :(
Hope this helps,
Sunitha.
Rather, I feel question for adding (local) variable , because I don't
want to increase number of variable even if it is local ....
Best regards.
/*
Tomohito Nakayama
[EMAIL PROTECTED]
[EMAIL PROTECTED]
[EMAIL PROTECTED]
Naka
http://www5.ocn.ne.jp/~tomohito/TopPage.html
*/
----- Original Message ----- From: "Sunitha Kambhampati (JIRA)"
<[email protected]>
To: <[email protected]>
Sent: Friday, September 30, 2005 2:13 AM
Subject: [jira] Commented: (DERBY-525) getAsciiStreamshould replace
non-ASCII characters with 0x3f, '?' to match embedded
[
http://issues.apache.org/jira/browse/DERBY-525?page=comments#action_12330828
]
Sunitha Kambhampati commented on DERBY-525:
-------------------------------------------
It would be great if you could add a testcase for this.
I looked at the patch briefly, and had one minor comment. In
convertToAsciiByteArray, it might be better performance wise, if we
calculate the original.length only once and use it in the for loop.
