Testing how long it takes to assign a variable versus assigning through WordPress’ apply_filters(). Filters are core to WordPress, but I haven’t yet looked at the total number of apply_filters() calls used throughout the code. The answer to this question is that calling a non-existing filter before assignment is about 21 times more costly than […] » about 300 words
Question: Should you check for a file before attempting to include it, or just suppress errors? Calling file_exists requires stating it twice if the file does exist, so that could take longer. Answer: the file_exists pattern is more than five times faster than the @include pattern for a file that doesn’t exist, and not substantially […] » about 300 words
An argument has erupted over the WordPress actions wp_enqueue_scripts and admin_enqueue_scripts vs. init. One of the points was about specificity, and how wp_enqueue_scripts and admin_enqueue_scripts can reduce ambiguity. I didn’t realize I had strong opinions on it until the issue was pressed, but it turns out I think wp_enqueue_scripts and admin_enqueue_scripts are unnecessary and unfortunate additions […] » about 300 words
A short test to confirm references are preserved in cloned arrays. The result is: Now let’s mess with one piece of that to check if the object was passed by reference or got cloned: Confirmed, the object is passed by reference, even though the array that contained it was cloned: » about 300 words
Note: since return() is a language construct and not a function, the parentheses surrounding its arguments are not required. It is common to leave them out, and you actually should do so as PHP has less work to do in this case.
I knew the parentheses were optional, but I’ve been merrily using them all along. And I probably would have continued doing so until I saw the second note attached to the docs:
Note: You should never use parentheses around your return variable when returning by reference, as this will not work. You can only return variables by reference, not the result of a statement. If you use return ($a); then you’re not returning a variable, but the result of the expression ($a) (which is, of course, the value of $a).
This two year old post about Rasmus Lerdorf’s PHP scaling tips (slides) is interesting in the context of what we’ve learned since then. APC now seems common, and it’s supposedly built-in to PHP6. Still, I’d be interested in seeing an update. Are MySQL prepared statements still slow?
And that’s where Rasmus’ latest presentation comes in. We don’t learn anything about MySQL prepared statements, but we do learn how to find choke points in our applications using callgrind and other tools. In his examples, he can do a little over 600 transactions per second with both static HTML and simple PHP, but various frameworks — with many inclusions and function calls — can slow that to under 50 transactions per second (I suppose they’d explain that in a TPS report).
2. Install APC using pear (the pear installer is smarter than the pecl installer):
When the installer asks about APXS, say ‘no’. </p> <div class="wp_syntax">
pear install pecl/apc
I’ve been pretty aware of the risks of SQL injection and am militant about keeping my database interactions clean. Mark Jaquith today reminded me about the need to make sure my browser output is filtered through clean_url(), sanitize_url(), and attribute_escape(). Furthermore, we all need to remember current_user_can(), check_admin_referer(), and nonces. » about 100 words
I’ve got a PHP script that sometimes just dies with no errors to the browser and no messages in the error log. I’ve seen this in the past with scripts that consumed too much memory (yeah, it should have issued an error, but it didn’t, and increasing the memory limit fixed it), but now the memory limit is set pretty high and I’m not sure I want to increase it further. I certainly don’t want to increase it without seeing where it’s going wrong, anyway.
Stuck with PHP 5.1.6 on RHEL or even CentOS (and a sysadmin who insists on using packages)? Need JSON? I did. The solution is easy:
yum install php-devel<br /> pecl install json
The pecl install failed when it hit an 8MB memory limit, and I was clueless about how to fix it until I learned that the pecl installer ignores the php.ini. Turns out the best solution is to use the pear installer (which does follow php.ini settings):
p0ps Harlow tweeted something about trying to get an AMP environment running on his Mac. Conversation followed, and eventually I sent along an email that look sorta like this: If you’re running 10.4 (I doubt it, but it’s worth mentioning because I’m most familiar with it), here’s how I’ve setup dozens of machines for web […] » about 300 words
I’ve been working on MySQL optimization for a while, and though there’s still more to done on that front, I’ve gotten to the point where the the cumulative query times make up less than half of the page generation time. So I’m optimizing code when the solution is obvious (and I hope to rope Zach […] » about 500 words
I expected a record that looked like this: LEADER 00000nas 2200000Ia 4500 001 18971047 008 890105c19079999mau u p 0uuua0eng 010 07023955 /rev 040 DLC|cAUG 049 PSMM 050 F41.5|b.A64 090 F41.5|b.A64 110 2 Appalachian Mountain Club 245 14 The A.M.C. White Mountain guide :|ba guide to trails in the mountains of New Hampshire and adjacent parts […] » about 600 words