Bug #63380 [Asn]: Allocation via libxml does not use PHP's per-request allocator
Edit report at https://bugs.php.net/bug.php?id=63380&edit=1
ID: 63380
Updated by: tstarling@php.net
Reported by: tstarling@php.net
Summary: Allocation via libxml does not use PHP's per-request
allocator
Status: Assigned
Type: Bug
Package: XML related
Operating System: Linux
PHP Version: master-Git-2012-10-29 (Git)
Assigned To: rrichards
Block user comment: N
Private report: N
New Comment:
https://github.com/php/php-src/pull/223
Previous Comments:
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[2012-10-29 03:25:17] tstarling@php.net
Description:
------------
Allocation via libxml does not use PHP's per-request allocator. So any memory used by libxml
will not be accounted against memory_get_usage() or memory_limit.
At Wikimedia we use libxml DOM trees to store wikitext parse trees, because they are more compact in
memory than the equivalent pure-PHP data structures. When these parse trees are cached, the memory
requirements can become excessive, and the memory is typically not returned to the system after
request termination. Using xmlMemSetup() to set hook functions which use PHP's per-request
allocation functions will allow us to more effectively monitor and limit the use of libxml in
production.
I've developed a patch and will submit it to GitHub as a pull request.
Test script:
---------------
$doc = new DOMDocument;
for ( $i = 0; $i < 1000000 ; $i++ ) {
$doc->appendChild($doc->createElement('foo'));
}
print memory_get_usage()."\n";
Expected result:
----------------
312331440 (with debug and ZTS)
Actual result:
--------------
694256
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Edit this bug report at https://bugs.php.net/bug.php?id=63380&edit=1
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