From fa7e5bd90199576bb7bce9b57569d3382f0a9993 Mon Sep 17 00:00:00 2001
From: Thiemo Kreuz <thiemo.kreuz@wikimedia.de>
Date: Mon, 17 Dec 2018 11:58:55 +0100
Subject: [PATCH] Avoid expensive array_shift where possible

array_shift manipulates the original array. This is surprisingly
expensive, because it iterates *all* elements in the array and
decrements numeric keys. The code touched in this patch does not need
this restructured new array, but only the individual elements.

Change-Id: Iee28377b2c9930f6de821e041381a1d7564f7633
---
 includes/Title.php                  | 13 +++++++------
 includes/cache/CacheHelper.php      |  4 ++--
 includes/htmlform/HTMLForm.php      |  6 +-----
 includes/htmlform/HTMLFormField.php |  3 +--
 4 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/includes/Title.php b/includes/Title.php
index 038e8b1b20..f4c3abe1c1 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -2858,10 +2858,12 @@ class Title implements LinkTarget {
 		}
 
 		$errors = [];
-		while ( count( $checks ) > 0 &&
-				!( $short && count( $errors ) > 0 ) ) {
-			$method = array_shift( $checks );
+		foreach ( $checks as $method ) {
 			$errors = $this->$method( $action, $user, $errors, $rigor, $short );
+
+			if ( $short && $errors !== [] ) {
+				break;
+			}
 		}
 
 		return $errors;
@@ -5218,10 +5220,9 @@ class Title implements LinkTarget {
 
 		if ( MWNamespace::hasSubpages( $this->mNamespace ) ) {
 			// Optional notice for page itself and any parent page
-			$parts = explode( '/', $this->mDbkeyform );
 			$editnotice_base = $editnotice_ns;
-			while ( count( $parts ) > 0 ) {
-				$editnotice_base .= '-' . array_shift( $parts );
+			foreach ( explode( '/', $this->mDbkeyform ) as $part ) {
+				$editnotice_base .= '-' . $part;
 				$msg = wfMessage( $editnotice_base );
 				if ( $msg->exists() ) {
 					$html = $msg->parseAsBlock();
diff --git a/includes/cache/CacheHelper.php b/includes/cache/CacheHelper.php
index 6c6b184735..93685e35af 100644
--- a/includes/cache/CacheHelper.php
+++ b/includes/cache/CacheHelper.php
@@ -270,8 +270,8 @@ class CacheHelper implements ICacheHelper {
 			$value = null;
 
 			if ( is_null( $key ) ) {
-				$itemKey = array_keys( array_slice( $this->cachedChunks, 0, 1 ) );
-				$itemKey = array_shift( $itemKey );
+				reset( $this->cachedChunks );
+				$itemKey = key( $this->cachedChunks );
 
 				if ( !is_int( $itemKey ) ) {
 					wfWarn( "Attempted to get item with non-numeric key while " .
diff --git a/includes/htmlform/HTMLForm.php b/includes/htmlform/HTMLForm.php
index 117a8fb912..1a7f8500d2 100644
--- a/includes/htmlform/HTMLForm.php
+++ b/includes/htmlform/HTMLForm.php
@@ -344,11 +344,7 @@ class HTMLForm extends ContextSource {
 
 			$setSection =& $loadedDescriptor;
 			if ( $section ) {
-				$sectionParts = explode( '/', $section );
-
-				while ( count( $sectionParts ) ) {
-					$newName = array_shift( $sectionParts );
-
+				foreach ( explode( '/', $section ) as $newName ) {
 					if ( !isset( $setSection[$newName] ) ) {
 						$setSection[$newName] = [];
 					}
diff --git a/includes/htmlform/HTMLFormField.php b/includes/htmlform/HTMLFormField.php
index 5f99aa0ca5..818474d47e 100644
--- a/includes/htmlform/HTMLFormField.php
+++ b/includes/htmlform/HTMLFormField.php
@@ -137,8 +137,7 @@ abstract class HTMLFormField {
 		for ( $i = count( $thisKeys ) - 1; $i >= 0; $i-- ) {
 			$keys = array_merge( array_slice( $thisKeys, 0, $i ), $nameKeys );
 			$data = $alldata;
-			while ( $keys ) {
-				$key = array_shift( $keys );
+			foreach ( $keys as $key ) {
 				if ( !is_array( $data ) || !array_key_exists( $key, $data ) ) {
 					continue 2;
 				}
-- 
2.20.1