Re: [PHP] Benchmarking check to see if array key is set
Ford, Mike wrote: On 06 November 2007 12:57, Christoph Boget wrote: Consider the following test code: [...snip...] Running that I found that if( isset( $myArray[$key] )) is faster than if( array key exists( $key, $myArray )) is faster than if( $myArray[$key] ) To be honest, I was surprised. I would have thought that if( $myArray[$key] ) would have been the fastest way to check. I'm wondering if those in the know could explain why it's the slowest and also where the discrepancies come from w/r/t the difference in the amount of time it takes to make each check. OK, I'll take a stab. Firstly, isset() is a language construct not an actual function, so the only thing your isset() does is check whether the array element exists. Next, array_key_exists() is the only one that involves a real function call, so it's going to bear that cost. However, the function then does a pretty simple test which again only involves checking whether the key exists, so the function itself is going to be pretty quick. Finally, the if() is the only one that actually gets the value in $myArray[$key], and then casts it to Boolean to boot, and the cost of this must therefore outweigh the cost of a function call plus a check for a key's existence. I'm certainly not surprised that isset() is the quickest, because it does the simplest test, but to be honest I'm not sure if I'd have predicted the relative positions of the other two.. Cheers! Mike For convenience let's label the cases: 1: if( isset( $myArray[$key] )) 2: if( array key exists( $key, $myArray )) 3: if( $myArray[$key] ) Now, surely 3 is not comparable at all to 1 and 2. Cases 1 and 2 check that the key exists in the array. Case 3 does a boolean test on the value referenced by the key. That has several consequences: Firstly, if there is no element with key $key in the arrray, the interpreter will throw an error (undefined index ...); this error could be suppressed and ignored, I suppose. Secondly, if the value referenced by the key is equivalent to FALSE, then the test will return FALSE; for example, if you have set $myArray[$key]='' or $myArray[$key]=0. This could be very confusing. So if you want to test that the key exists, case 3 is NOT the way to do it. In fact, you will often want to check that the key exists(with case 1, ideally) BEFORE using a test of the form of case 3. Cheers Pete Ford (no relation, I think, although I do have a cousin called Michael...) -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Benchmarking check to see if array key is set
Consider the following test code:
?php
$myArray = array();
for( $i = 0; $i = 1; $i++ )
{
$date = microtime( TRUE );
$key = rand( $date, $date * rand( 1, 5000 ));
$myArray[$key] = $key;
}
echo '$myArray items created: ' . count( $myArray ) . 'brbr';
$startTime = microtime( TRUE );
$foundCount = 0;
for( $i = 0; $i = 1; $i++ )
{
$date = microtime( TRUE );
$key = rand( $date, $date * rand( 1, 5000 ));
if( array key exists( $key, $myArray ))
{
$foundCount++;
}
}
$endTime = microtime( TRUE );
echo 'array key exists took [' . ( $endTime - $startTime ) . '] seconds;
found: [' . $foundCount . '] keysbrbr';
$startTime = microtime( TRUE );
$foundCount = 0;
for( $i = 0; $i = 1; $i++ )
{
$date = microtime( TRUE );
$key = rand( $date, $date * rand( 1, 5000 ));
if( isset( $myArray[$key] ))
{
$foundCount++;
}
}
$endTime = microtime( TRUE );
echo 'isset took [' . ( $endTime - $startTime ) . '] seconds; found: [' .
$foundCount . '] keysbrbr';
$startTime = microtime( TRUE );
$foundCount = 0;
for( $i = 0; $i = 1; $i++ )
{
$date = microtime( TRUE );
$key = rand( $date, $date * rand( 1, 5000 ));
if( $myArray[$key] )
{
$foundCount++;
}
}
$endTime = microtime( TRUE );
echo 'IF() took [' . ( $endTime - $startTime ) . '] seconds; found: [' .
$foundCount . '] keysbrbr';
?
Running that I found that
if( isset( $myArray[$key] ))
is faster than
if( array key exists( $key, $myArray ))
is faster than
if( $myArray[$key] )
To be honest, I was surprised. I would have thought that if( $myArray[$key]
) would have been the fastest way to check. I'm wondering if those in the
know could explain why it's the slowest and also where the discrepancies
come from w/r/t the difference in the amount of time it takes to make each
check.
thnx,
Chris
RE: [PHP] Benchmarking check to see if array key is set
On 06 November 2007 12:57, Christoph Boget wrote: Consider the following test code: [...snip...] Running that I found that if( isset( $myArray[$key] )) is faster than if( array key exists( $key, $myArray )) is faster than if( $myArray[$key] ) To be honest, I was surprised. I would have thought that if( $myArray[$key] ) would have been the fastest way to check. I'm wondering if those in the know could explain why it's the slowest and also where the discrepancies come from w/r/t the difference in the amount of time it takes to make each check. OK, I'll take a stab. Firstly, isset() is a language construct not an actual function, so the only thing your isset() does is check whether the array element exists. Next, array_key_exists() is the only one that involves a real function call, so it's going to bear that cost. However, the function then does a pretty simple test which again only involves checking whether the key exists, so the function itself is going to be pretty quick. Finally, the if() is the only one that actually gets the value in $myArray[$key], and then casts it to Boolean to boot, and the cost of this must therefore outweigh the cost of a function call plus a check for a key's existence. I'm certainly not surprised that isset() is the quickest, because it does the simplest test, but to be honest I'm not sure if I'd have predicted the relative positions of the other two. Cheers! Mike - Mike Ford, Electronic Information Services Adviser, JG125, The Headingley Library, James Graham Building, Leeds Metropolitan University, Headingley Campus, LEEDS, LS6 3QS, United Kingdom Email: [EMAIL PROTECTED] Tel: +44 113 812 4730 Fax: +44 113 812 3211 To view the terms under which this email is distributed, please go to http://disclaimer.leedsmet.ac.uk/email.htm -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Benchmarking SPL Iterators vs for / foreach ???
On Sat, Nov 26, 2005 at 02:36:26PM +0200, Andrei Verovski (aka MacGuru) wrote: Hi, Someone have benchmarked SPL iterators vs for / foreach loops? What is the performance penalty? SPL is �interpreted wrapper� on the top of C++ STL (correct me if I am wrong), and I am sure it uses STL callbacks. But unlike C++, PHP scripts are interpreted, so pointer arithmetic will work only through Zend engine which for sure adds extra performance penalty. I think you're confused at what SPL is in php: http://php.net/spl Curt. -- cat .signature: No such file or directory -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Benchmarking SPL Iterators vs for / foreach ???
Hi, Someone have benchmarked SPL iterators vs for / foreach loops? What is the performance penalty? SPL is ¨interpreted wrapper¨ on the top of C++ STL (correct me if I am wrong), and I am sure it uses STL callbacks. But unlike C++, PHP scripts are interpreted, so pointer arithmetic will work only through Zend engine which for sure adds extra performance penalty. Thanks in advance for any suggestion(s) *** with best regards *** Andrei Verovski (aka MacGuru) *** Mac, Linux, DTP, Programming Web Site *** *** http://snow.prohosting.com/guru4mac/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking a script
You will still get the benchmark of the functions, you just declare them
outside of your benchmarking loop so they don't get re-declared.
Pardon my syntax, I'm just going to try to demonstrate (using the
getmicrotime function from the PHP manual):
?php
Function dosomething ($somevar) {
echo $somevar;
return 1;
}
Function dosomethingelse ($somevar) {
echo $somevar;
return 1;
}
function getmicrotime()
{
list($usec, $sec) = explode( , microtime());
return ((float)$usec + (float)$sec);
}
# Benchmark here
$time_start = getmicrotime();
For ($i=0; $i = 10; $i++) {
$retval = dosomething($i);
$retval2 = dosomethingelse($i);
}
$time_end = getmicrotime();
$time = $time_end - $time_start;
# end benchmarking
?
Every time you call dosomething and dosomethingelse, it executes the
function, it just doesn't delare it over again. So even though your
functions are declared outside of your benchmark loop, they still get
executed inside the loop, therefore you get the time needed to execute
100,000 calls of both functions (in this case).
The only thing you're not benchmarking here is the time to declare the
functions once, which is extremely minimal.
Does that clarify it a bit for you?
-TG
-Original Message-
From: Cristian Lavaque [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 14, 2004 1:18 PM
To: Gryffyn, Trevor
Subject: Re: [PHP] Benchmarking a script
Hello Trevor,
I really appreciate your reply! In fact I haven't found a way
to do it
yet. I can't really do it the way you suggest cause part of
what I want
to benchmark is defining the functions. Someone suggested benching it
from Apache, but I'm not sure how to do that. Thank you very much for
taking the time to drop me an email. :)
Regards,
Cristian
Gryffyn, Trevor wrote:
Doesn't look like anyone responded to this (publicly at least). I
wasn't sure if you were still having a problme, but
something you might
try is putting the function definitions outside of the
loop. They'll
get called once, and still be executed within the loop.
Good luck!
-TG
__
_
This message has been checked by mks_vir mail scanner (
http://www.mks.com.pl )
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[PHP] Benchmarking a script
Hello,
I have a script I am optimizing and want to compare the before and after
in speed. So I wrote a few lines to loop this script but I have a
problem. In the script I'm optimizing there's some function definitions
and when the script starts the second iteration it throws an error
because the function already exists. How can I modify my benchmark code
to make it work? This is what I have:
?php
$bench_n = 1000;
for($bench_i=$bench_n; --$bench_i=0; ){
ob_start();
$bench_time1 = array_sum(explode(' ', microtime()));
// script start
// script...
// script end **
$bench_time0 += array_sum(explode(' ', microtime())) - $bench_time1;
while(@ob_end_clean());
}
echo 'preTot Time: ' , $bench_time0 , 'br /Loops:' , $bench_n ,
'br /Avg Time: ' , ($bench_time0 / $bench_n) , '/pre';
?
Thank you very much in advance.
Cristian
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[PHP] Benchmarking PHP vs ASP.net
Hello, Many people ask me if ASP.net is faster than PHP. I know for a fact that it is (because PHP is not optimized). But then what about optimized PHP and compiled ASP.net. This would be a fairer comparison in my opinion. Anyone seen any benchmarks of this? If so please let me know as I would not like to pass on any wrong info. Thanks - Sid -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking PHP vs ASP.net
Apparently if you read the terms of agreement when installing .NET you can't publish your benchmarking results without their permission. just a thought. would be interesting to see comparison, and maybe also JSP, cold fusion -Original Message- From: Sid [mailto:[EMAIL PROTECTED] Sent: Monday, September 08, 2003 2:17 PM To: [EMAIL PROTECTED] Subject: [PHP] Benchmarking PHP vs ASP.net Hello, Many people ask me if ASP.net is faster than PHP. I know for a fact that it is (because PHP is not optimized). But then what about optimized PHP and compiled ASP.net. This would be a fairer comparison in my opinion. Anyone seen any benchmarks of this? If so please let me know as I would not like to pass on any wrong info. Thanks - Sid -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking PHP vs ASP.net
[snip] Many people ask me if ASP.net is faster than PHP. I know for a fact that it is (because PHP is not optimized). But then what about optimized PHP and compiled ASP.net. This would be a fairer comparison in my opinion. Anyone seen any benchmarks of this? If so please let me know as I would not like to pass on any wrong info. [/snip] As has been mentioned several times, comparing ASP.net (or 'plain' ASP) to PHP is comparing apples and oranges unless you are comparing the processing engine itself. In this day and age where processor power is what it is and growing according to Moore, speed comparisons are basically fodder for smirking 'my server can beat up your server'. Let's say I have a database with 1 million records. I need to update 10,000 of those records. On the same server code supported by ASP.net runs in 1.032 seconds while code in PHP runs in 1.067 seconds. OMG! PHP is slower. The difference is .035 seconds. Does this matter? Who is asking which is faster? Why do they care? Are they looking for a reason to choose one technology over another? Since ASP.net namespaces are compiled that creates a fundamental difference when comparing to PHP. What language are you using to create the ASP.net namespace? All in all I think it a waste to even entertain a resposnse to folks who would ask this question other than to say 'a comparison between these technologies is impossible due to the differences'. Have a pleasant and productive day. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking PHP vs ASP.net
Apparently if you read the terms of agreement when installing .NET you can't publish your benchmarking results without their permission. Is Micro$oft©® scared of being beaten? Now I am going to get the benchmarking results by hook or crook! Now I HATE M$. aahh!! I've seen a comparison of JSP PHP and CF (Don't remember where - All I know is that it came up among the top results in google for I think 'ASP.net vs PHP') - Sid On Mon, 08 Sep 2003 14:25:20 +0200, Angelo Zanetti wrote: Apparently if you read the terms of agreement when installing .NET you can't publish your benchmarking results without their permission. just a thought. would be interesting to see comparison, and maybe also JSP, cold fusion -Original Message- From: Sid [mailto:[EMAIL PROTECTED] Sent: Monday, September 08, 2003 2:17 PM To: [EMAIL PROTECTED] Subject: [PHP] Benchmarking PHP vs ASP.net Hello, Many people ask me if ASP.net is faster than PHP. I know for a fact that it is (because PHP is not optimized). But then what about optimized PHP and compiled ASP.net. This would be a fairer comparison in my opinion. Anyone seen any benchmarks of this? If so please let me know as I would not like to pass on any wrong info. Thanks - Sid -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking PHP vs ASP.net
OMG! PHP is slower. The difference is .035 seconds. Does this matter? Who is asking which is faster? Why do they care? Are they looking for a reason to choose one technology over another? Throw In 2 Cents I totally agree with you, but I find it funny that many times when talking to people they don't seem to realize that unless you are talking about an enterprise solution for a Fortune 500 company, it is the /developer/ time that costs the most. So let's assume a developer can get a solution done in PHP in a weeks worth of work and in ASP.net for 2 weeks. Then you have spent enough to buy a second server for redundancy on a solution that is .035 seconds faster. But hey, I don't complain much. It keeps me employed. /Throw In 2 Cents -Dan -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Benchmarking PHP vs ASP.net
Can't resist trowing in my 0.02 either: As dan pointed out it's so much faster to do things in php. When you take into consideration the fact that code on windows never work the way it's supposed you are saving a lot of man hours. Second point worth mentioning is that a given languages/frameworks will be faster at certains tasks while slower at another task. Thus as jay has explained generic benchmarks are realy of little significance. Dan Anderson wrote: OMG! PHP is slower. The difference is .035 seconds. Does this matter? Who is asking which is faster? Why do they care? Are they looking for a reason to choose one technology over another? Throw In 2 Cents I totally agree with you, but I find it funny that many times when talking to people they don't seem to realize that unless you are talking about an enterprise solution for a Fortune 500 company, it is the /developer/ time that costs the most. So let's assume a developer can get a solution done in PHP in a weeks worth of work and in ASP.net for 2 weeks. Then you have spent enough to buy a second server for redundancy on a solution that is .035 seconds faster. But hey, I don't complain much. It keeps me employed. /Throw In 2 Cents -Dan -- http://www.radinks.com/upload Drag and Drop File Uploader. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking PHP vs ASP.net
--- Sid [EMAIL PROTECTED] wrote: Many people ask me if ASP.net is faster than PHP. I know for a fact that it is (because PHP is not optimized). Don't be so easily fooled by hollow terms. Go here: http://public.yahoo.com/~radwin/talks/yahoo-phpcon2002.htm Start with the slide entitled Benchmarking PHP. You'll see PHP perform against yScript2, the second generation of Yahoo!'s proprietary C/C++ engine, and YSP, an extremely fast mod_perl based solution. Why bother comparing PHP to ASP in terms of performance when it can compete with the performance of two of the fastest engines in the world? People don't choose ASP for performance. Here is another benchmark: http://www.chamas.com/bench/index.html If you want some opinions on how the languages compare, search Google. Here is a link I found: http://www.netconcepts.com/news/php_vs_asp.php I've seen a comparison of JSP PHP and CF (Don't remember where - All I know is that it came up among the top results in google for I think 'ASP.net vs PHP') Yes, PHP was the top performer and ColdFusion was the easiest to develop in. Lastly, ASP ties you to a particular platform, and a particularly bad one at that. Choose ASP if you're an NBM shop. Choose mod_perl if you really need that fractional increase in speed. Choose PHP if you like it. Choose JSP if you're really into Java and think complaints about its performance are unfounded. Choose ColdFusion if you can write HTML and think that qualifies you as a Web developer. Most importantly, don't choose a language based on what someone on a mailing list tells you. :-) Hope that helps. Chris = Become a better Web developer with the HTTP Developer's Handbook http://httphandbook.org/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Benchmarking
Hi, I've been making a web ap PHP based, but I fear the number of arrays it has is too big. Is there any way to benchmark a script, or are there any recomendations or standards about how much time execution takes and how many resources it takes? Thanks, Reven -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking
I've been making a web ap PHP based, but I fear the number of arrays it has is too big. Is there any way to benchmark a script, or are there any recomendations or standards about how much time execution takes and how many resources it takes? The benchmarking is just a matter of subtracting the time at the end of your script from the time at the beginning. Check your web server logs for the resources question. I don't know of any PHP way to do it. ---John W. Holmes... PHP Architect - A monthly magazine for PHP Professionals. Get your copy today. http://www.phparch.com/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] benchmarking used memory
Hi, I would like to know if there is way to measure how much memory a script uses during execution. Althought threre is no such function in the manual, in my opinion there must be some indication how much memory is used because of the memory_limit directive in the php.ini file. So if php is able to determine the maximum level it should be able and to give indication and for the actual. Thanks in advance Peio Popov -- --- Peio Popov - [EMAIL PROTECTED] icq# 117130734 http://www.cilaw.org -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] php benchmarking suite
Is anyone aware of a php benchmarking suite comparable in functionality to perls Benchmark.pm? // George Schlossnagle // Principal Consultant // OmniTI, Inc http://www.omniti.com // (c) 240.460.5234 (e) [EMAIL PROTECTED] // 1024D/1100A5A0 1370 F70A 9365 96C9 2F5E 56C2 B2B9 262F 1100 A5A0 -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Benchmarking a site...
Hi, is it possible to benchmark a site/page which uses authentication via PHP sessions?. If so, could you please tell me some hints to do it?. Thank you. Rodolfo. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
RE: [PHP] Benchmarking a site...
is it possible to benchmark a site/page which uses authentication via PHP sessions?. If so, could you please tell me some hints to do it?. Why does it matter if the page is authenticated? Get the time at the beginning, the time at the end of the page, subtract smaller from larger, and you've got how long it took the page to be created I think PEAR has a module that provides a nice interface for doing this and I'm sure there are others. ---John Holmes... -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] benchmarking php scripts
Is there a way to benchmark a PHP script to see how intensive it is? For example, execution time, CPU/RAM/disk usage, etc. Thanks in advance. -- Eugene Lee [EMAIL PROTECTED] -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
