* Implement iteration cache, item cache and length cache for node list iteration
The current implementation follows the spec requirement that the list
must be "live". This means that changes in the document must be
reflected in the existing node lists without requiring the user to
refetch the node list.
The consequence is that getting any item, or the length of the list,
always starts searching from the root element of the node list. This
results in O(n) time to get any item or the length. If there's a for
loop over the node list, this means the iterations will take O(n²) time
in total. This causes real-world performance issues with potential for
downtime (see GH-11308 and its references for details).
We fix this by introducing a caching strategy. We cache the last
iterated object in the iterator, the last requested item in the node
list, and the last length computation. To invalidate the cache, we
simply count the number of modifications made to the containing
document. If the modification number does not match what the number was
during caching, we know the document has been modified and the cache is
invalid. If this ever overflows, we saturate the modification number and
don't do any caching anymore. Note that we don't check for overflow on
64-bit systems because it would take hundreds of years to overflow.
Fixes GH-11308.
This reverts commit 94ee4f9834.
The commit was a bit too late to be included in PHP 8.2 RC1. Given it's a massive ABI break, we decide to postpone the change to PHP 8.3.
1. Update: http://www.php.net/license/3_01.txt to https, as there is anyway server header "Location:" to https.
2. Update few license 3.0 to 3.01 as 3.0 states "php 5.1.1, 4.1.1, and earlier".
3. In some license comments is "at through the world-wide-web" while most is without "at", so deleted.
4. fixed indentation in some files before |
We're starting to see a mix between uses of zend_bool and bool.
Replace all usages with the standard bool type everywhere.
Of course, zend_bool is retained as an alias.
Return the original value. If we don't return the original value,
we need to own the zval, which we don't.
For clarity also switch things to work on a zend_string* value
instead of a zval*.
Context: https://externals.io/message/108789
This essentially moves the functionality of SimpleXMLIterator into
SimpleXMLElement, and makes SimpleXMLIterator a no-op extension.
Ideally SimpleXMLElement would be an IteratorAggregate, whose
getIterator() method returns SimpleXMLIterator. However, because
SimpleXMLIterator extends SimpleXMLElement (and code depends on
this in non-trivial ways), this is not possible.
The only way to not keep SimpleXMLElement as a magic Traversable
(that implements neither Iterator nor IteratorAggregate) is to
move the SimpleXMLIterator functionality into it.
Closes GH-5234.
