#34700 [Asn->Csd]: performance problem with date()
ID: 34700
Updated by: derick@php.net
Reported By: six at aegis-corp dot org
-Status: Assigned
+Status: Closed
Bug Type: Date/time related
Operating System: *
PHP Version: 5CVS-2005-10-02
Assigned To: derick
New Comment:
This bug has been fixed in CVS.
Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
Thank you for the report, and for helping us make PHP better.
The syscall has been eliminated and the tzcache is in place now in CVS.
It is still slower, but not as bad as it was. Also, things improve
greatly if you use the date.timezone setting in php.ini to select the
timezone (in the format "America/New_York" f.e.) that you are actually
in.
Previous Comments:
------------------------------------------------------------------------
[2005-10-01 21:22:28] derick@php.net
So that I can't forget this.
------------------------------------------------------------------------
[2005-10-01 20:14:39] rasmus@php.net
Right, the timezone lookup is currently slower. There needs to be a
cache layer in front of it. It will come eventually. We know about
it.
------------------------------------------------------------------------
[2005-10-01 19:11:16] six at aegis-corp dot org
sniper: the latest cvs exhibits the same problem.
rasmus: $_SERVER["REQUEST_TIME"] is a nice addition, but in my case I
just want to convert timestamps stored in a db to a readable format,
hence no need for the current time at all ...
the following patch address the unneeded call to time(NULL), strace
confirms it, but the performance is still not on par with 5.0
--- php5-200510011430/ext/date/php_date.c.orig 2005-10-01
18:16:55.000000000 +0200
+++ php5-200510011430/ext/date/php_date.c 2005-10-01
18:17:48.000000000 +0200
@@ -479,11 +479,23 @@
{
char *format;
int format_len;
- time_t ts = time(NULL);
+ time_t ts;
char *string;
- if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|l",
&format, &format_len, &ts) == FAILURE) {
- RETURN_FALSE;
+ switch (ZEND_NUM_ARGS()) {
+ case 2:
+ if (zend_parse_parameters(2 TSRMLS_CC, "sl", &format,
&format_len, &ts) == FAILURE) {
+ RETURN_FALSE;
+ }
+ break;
+ case 1:
+ if (zend_parse_parameters(1 TSRMLS_CC, "s", &format,
&format_len) == FAILURE) {
+ RETURN_FALSE;
+ }
+ ts = time(NULL);
+ break;
+ default:
+ WRONG_PARAM_COUNT;
}
string = php_format_date(format, format_len, ts, localtime
TSRMLS_CC);
------------------------------------------------------------------------
[2005-10-01 17:13:34] rasmus@php.net
One of the new things in PHP 5.1 is the $_SERVER['REQUEST_TIME']
variable that gets set to the request time. When running under Apache
this comes directly from the time syscall Apache makes for every
request, so by using this you can actually eliminate any time-related
syscalls at the PHP level and still do time stuff in a PHP script. But
yes, it looks like there are a few things that can be cleaned up here.
------------------------------------------------------------------------
[2005-10-01 16:07:27] six at aegis-corp dot org
Description:
------------
performance of the date() function has taken a huge hit between PHP 5.0
and 5.1. i believe this is because of an unneeded syscall when a second
argument is given.
Reproduce code:
---------------
<?
for ($a = 0; $a < 100000; $a++) date("Y-m-d H:i:s", $a);
?>
Expected result:
----------------
time /usr/local/bin/php-cli-5.0.4 datetest.php
real 0m2.022s
user 0m1.910s
sys 0m0.000s
Actual result:
--------------
time /usr/local/bin/php-cli-5.1.0RC1 datetest.php
real 0m10.001s
user 0m8.120s
sys 0m0.130s
5.1.0 takes more than 4x the time to complete than 5.0.4
with an strace, I can see that 5.1.0RC1 makes one (probably unneeded)
time() syscall per call to date(), which 5.0.4 does not
------------------------------------------------------------------------
--
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