* 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.
I was surprised to see that getting the stricterror property showed in
in the Callgrind profile of some tests. Turns out we sometimes allocate
them. Fix this by returning the default in case no changes were made yet.
Closes GH-11345.
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 |
This patch removes the so called local variables defined per
file basis for certain editors to properly show tab width, and
similar settings. These are mainly used by Vim and Emacs editors
yet with recent changes the once working definitions don't work
anymore in Vim without custom plugins or additional configuration.
Neither are these settings synced across the PHP code base.
A simpler and better approach is EditorConfig and fixing code
using some code style fixing tools in the future instead.
This patch also removes the so called modelines for Vim. Modelines
allow Vim editor specifically to set some editor configuration such as
syntax highlighting, indentation style and tab width to be set in the
first line or the last 5 lines per file basis. Since the php test
files have syntax highlighting already set in most editors properly and
EditorConfig takes care of the indentation settings, this patch removes
these as well for the Vim 6.0 and newer versions.
With the removal of local variables for certain editors such as
Emacs and Vim, the footer is also probably not needed anymore when
creating extensions using ext_skel.php script.
Additionally, Vim modelines for setting php syntax and some editor
settings has been removed from some *.phpt files. All these are
mostly not relevant for phpt files neither work properly in the
middle of the file.
The $Id$ keywords were used in Subversion where they can be substituted
with filename, last revision number change, last changed date, and last
user who changed it.
In Git this functionality is different and can be done with Git attribute
ident. These need to be defined manually for each file in the
.gitattributes file and are afterwards replaced with 40-character
hexadecimal blob object name which is based only on the particular file
contents.
This patch simplifies handling of $Id$ keywords by removing them since
they are not used anymore.
