From: webmaster at maczsoftware dot com
Operating system: RedHat Linux 8.0
PHP version: 4.3.2RC4
PHP Bug Type: Output Control
Bug description: Performance of ob_start() is bad when lot of HTML data is printed
afterwards
I'm having some pretty weird issues with ob_start() function. I have a
merely complex script, which parses XML file (its functionality is located
in own class, which is included from another php file). Because this
script can output pretty much data, I'm buffering the output and then send
it to browser gzipped.
However, the execution time of my script is 23 seconds with large XML
file, so I started to investigate possibilities of optimization. I thought
- of course - that XML parsing was taking too long, but when I started to
count seconds with getmicrotime() function, I found out that
ob_start("ob_gzhandler") was taking 14 seconds of that 23!
So I suppose this could be a bug in the PHP. I'm not saying that the
script is too slow, 23 secs can be completely possible, but that calling
getmicrotime() right before and right after ob_start() and getting 14 secs
can't be right.
All data is printed after ob_start() call, and at the end of the script
ob_end_flush() is called. I have also tried using non-gzipped output, with
pretty same processing time. The code which relates to this problem is
below:
Code:
$before = getmicrotime();
ob_start("ob_gzhandler");
$after = getmicrotime();
// Here comes some XML parsing and printing some large text data
// ...
print "Time usage for ob_start: " . ($after - $before) . " seconds\n";
ob_end_flush();
// This is standard getmicrotime from php.net
function getmicrotime()
{
list($usec, $sec) = explode(" ",microtime());
return ((float)$usec + (float)$sec);
}
---
PHP INFO:
PHP 4.3.2RC4 (cli) (built: May 22 2003 16:30:41)
Copyright (c) 1997-2003 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2003 Zend Technologies
Configure line:
./configure --with-mysql --with-apxs=/usr/local/apache/bin/apxs --with-gd
--with-zlib-dir=/usr/local --enable-memory-limit
--
Edit bug report at http://bugs.php.net/?id=23836&edit=1
--
Try a CVS snapshot: http://bugs.php.net/fix.php?id=23836&r=trysnapshot
Fixed in CVS: http://bugs.php.net/fix.php?id=23836&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=23836&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=23836&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=23836&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=23836&r=support
Expected behavior: http://bugs.php.net/fix.php?id=23836&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=23836&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=23836&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=23836&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=23836&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=23836&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=23836&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=23836&r=gnused
