about:benjie

Quote from SimplePie wiki:

When processing a large number of feeds (via a cron job or MySQL loop), a memory leak can occur causing PHP to run out of memory. This is due to PHP Bug #33595 where PHP doesn’t release memory when making recursive (i.e. self-referential) object calls.

This bug has troubled me for a while with Blog Friends, and caused me to stay with older versions of SimplePie. However, today I think I may have fixed it.

I have put up details of my fix on the SimplePie wiki page linked above, but reproduce them here (without syntax highlighting) for your convenience…

Possibly Solution

The problem is due to recursive references within SimplePie (and PHP’s poor handling of said references). A solution that works for me is patching the vanilla SimplePie 1.0.1 with this:

<code>
— simplepie1/simplepie.inc (revision 528)
+++ simplepie1/simplepie.inc (working copy)
@@ -668,6 +668,12 @@
$this->init();
}
}
+ function __destruct() {
+ if (isset($this->data['items']) && is_array($this->data['items'])) foreach (array_keys($this->data['items']) as $k) {
+ $this->data['items'][$k]->__destruct();
+ unset($this->data['items'][$k]);
+ }
+ }

/**
* Used for converting object to a string
@@ -1521,6 +1527,7 @@
return false;
}
}
+ $locate->__destruct();
$locate = null;

$headers = $file->headers;
@@ -2703,6 +2710,9 @@
$this->feed = $feed;
$this->data = $data;
}
+ function __destruct() {
+ unset($this->feed);
+ }

function __toString()
{
@@ -10013,6 +10023,9 @@
$this->timeout = $timeout;
$this->max_checked_feeds = $max_checked_feeds;
}
+ function __destruct() {
+ unset($this->file);
+ }

function find($type = SIMPLEPIE_LOCATOR_ALL)
{
</code>

Then all you have to do in your code is ensure that you call $sp->__destruct() once you are done with the SimplePie instance.

If you don’t need multiple concurrent SimplePie classes (i.e. you use SimplePie in a serial fashion) you could use a custom loader to do that… for example:

<code php>
function SimplePie_Loader($url) {
static $sp = NULL;
if ($sp !== NULL) {
$sp->__destruct();
$sp = NULL;
}
$sp = new SimplePie($url);
return $sp;
}
</code>

I hope this helps someone.

This entry was posted on Monday, August 27th, 2007 at 11:28 am by Benjie and is filed under Code, Internet. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.