From 98050e404d04140039f94cd38241a594b0b1b528 Mon Sep 17 00:00:00 2001
From: Boone Gorges <boonebgorges@gmail.com>
Date: Sat, 21 May 2016 17:27:29 +0000
Subject: [PATCH] Cache queries in `get_page_by_path()`.

Props spacedmonkey.
Fixes #36711.
Built from https://develop.svn.wordpress.org/trunk@37479


git-svn-id: http://core.svn.wordpress.org/trunk@37447 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/post.php    | 21 +++++++++++++++++++++
 wp-includes/version.php |  2 +-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/wp-includes/post.php b/wp-includes/post.php
index 1920e84f9a..ceaa1d96a8 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4231,6 +4231,24 @@ function get_page( $page, $output = OBJECT, $filter = 'raw') {
 function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
 	global $wpdb;
 
+	$last_changed = wp_cache_get( 'last_changed', 'posts' );
+	if ( false === $last_changed ) {
+		$last_changed = microtime();
+		wp_cache_set( 'last_changed', $last_changed, 'posts' );
+	}
+
+	$hash = md5( $page_path . serialize( $post_type ) );
+	$cache_key = "get_page_by_path:$hash:$last_changed";
+	$cached = wp_cache_get( $cache_key, 'posts' );
+	if ( false !== $cached ) {
+		// Special case: '0' is a bad `$page_path`.
+		if ( '0' === $cached || 0 === $cached ) {
+			return;
+		} else {
+			return get_post( $cached );
+		}
+	}
+
 	$page_path = rawurlencode(urldecode($page_path));
 	$page_path = str_replace('%2F', '/', $page_path);
 	$page_path = str_replace('%20', ' ', $page_path);
@@ -4285,6 +4303,9 @@ function get_page_by_path( $page_path, $output = OBJECT, $post_type = 'page' ) {
 		}
 	}
 
+	// We cache misses as well as hits.
+	wp_cache_set( $cache_key, $foundid, 'posts' );
+
 	if ( $foundid ) {
 		return get_post( $foundid, $output );
 	}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 8e44732726..2659386a23 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-alpha-37478';
+$wp_version = '4.6-alpha-37479';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.