Ticket #10852: new_get_page_children.php

<?php

class FakePost {
        public function __construct($ID, $post_parent) {
                $this->ID = $ID;
                $this->post_parent = $post_parent;
        }
}


function get_page_children( $page_id, $pages ) {
        $post_hash = array();
        $children_hash = array();

        // build a hash of ID -> children
        foreach ( (array) $pages as $page ) {
                $post_hash[$page->ID] = $page;
                if ( !array_key_exists( $page->post_parent, $children_hash ) ) {
                        $children_hash[$page->post_parent] = [$page->ID];
                } else {
                        $children_hash[$page->post_parent][] = $page->ID;
                }
        }

        if( array_key_exists( $page_id, $children_hash ) ) {
                $post_list = array();
                $to_look = array_reverse( $children_hash[$page_id] );
                // while we still have posts to_look add them to the list
                while ( $to_look ) {
                        $id = array_pop( $to_look );
                        $post_list[] = $post_hash[$id];
                        if ( array_key_exists( $id, $children_hash ) ) {
                                foreach( array_reverse( $children_hash[$id] ) as $child ) {
                                        $to_look[] = $child;
                                }
                        }
                }
                return $post_list;
        } else {
                return array();
        }
}

function old_get_page_children($page_id, $pages) {
        $page_list = array();
        foreach ( (array) $pages as $page ) {
                if ( $page->post_parent == $page_id ) {
                        $page_list[] = $page;
                        if ( $children = old_get_page_children($page->ID, $pages) ) {
                                $page_list = array_merge($page_list, $children);
                        }
                }
        }
        return $page_list;
}

function tests() {
        $pages = [];
        $pages[] = new FakePost(1, 0);
        $pages[] = new FakePost(2, 0);
        $pages[] = new FakePost(3, 2);
        $pages[] = new FakePost(4, 2);
        $pages[] = new FakePost(5, 0);
        for ($i=6; $i < 1000; $i++) {
                $pages[] = new FakePost($i, rand(0, $i-1));
        }
        $max_depth = 50;
        for ($i=1000; $i < (1000 + $max_depth); $i++) {
                $pages[] = new FakePost($i, $i-1);
        }
        for ($i=(1000 + $max_depth); $i < 2000; $i++) {
                $pages[] = new FakePost($i, 5);
        }
        for ($i=2000; $i < 4000; $i++) {
                $pages[] = new FakePost($i, 1);
        }

        for ($i=0; $i < 8; $i++) {
                $time = [];
                $r = [];

                $time_start = microtime(true);
                $r[] = get_page_children($i, $pages);
                $time[] = (int) ((microtime(true) - $time_start) * 1000);

                $time_start = microtime(true);
                $r[] = old_get_page_children($i, $pages);
                $time[] = (int) ((microtime(true) - $time_start) * 1000);

                echo ($r[0] == $r[1])?'Equal':'Different';
                echo " $time[0] ms (new), $time[1] ms (old)\n";
        }
}

tests();