Balancer: cache BalanceStack::currentNode()

Make currentNode into a public property instead of a function call, for
a performance improvement of about 4%.

Change-Id: I89861557531c55a63abef52c0acabbfb5c155bda

diff --git a/includes/tidy/Balancer.php b/includes/tidy/Balancer.php
index ed92238..a6bb575 100644 (file)
--- a/includes/tidy/Balancer.php
+++ b/includes/tidy/Balancer.php
@@ -629,6 +629,10 @@ class BalanceStack implements IteratorAggregate {
         * Tidy compatibility mode, determines behavior of body/blockquote
         */
        public $tidyCompat = false;
+       /**
+        * Reference to the current element
+        */
+       public $currentNode;
 
        /**
         * Create a new BalanceStack with a single BalanceElement on it,
@@ -640,6 +644,7 @@ class BalanceStack implements IteratorAggregate {
                        $this->elements,
                        new BalanceElement( BalanceSets::HTML_NAMESPACE, 'html', [] )
                );
+               $this->currentNode = $this->elements[0];
        }
 
        /**
@@ -666,17 +671,17 @@ class BalanceStack implements IteratorAggregate {
                Assert::parameterType( 'string', $value, '$value' );
                if (
                        $this->fosterParentMode &&
-                       $this->currentNode()->isA( BalanceSets::$tableSectionRowSet )
+                       $this->currentNode->isA( BalanceSets::$tableSectionRowSet )
                ) {
                        $this->fosterParent( $value );
                } elseif (
                        $this->tidyCompat &&
-                       $this->currentNode()->isA( BalanceSets::$tidyPWrapSet )
+                       $this->currentNode->isA( BalanceSets::$tidyPWrapSet )
                ) {
                        $this->insertHTMLELement( 'mw:p-wrap', [] );
                        return $this->insertText( $value );
                } else {
-                       $this->currentNode()->appendChild( $value );
+                       $this->currentNode->appendChild( $value );
                }
        }
 
@@ -719,7 +724,7 @@ class BalanceStack implements IteratorAggregate {
        public function insertElement( $elt ) {
                Assert::parameterType( 'MediaWiki\Tidy\BalanceElement', $elt, '$elt' );
                if (
-                       $this->currentNode()->isA( 'mw:p-wrap' ) &&
+                       $this->currentNode->isA( 'mw:p-wrap' ) &&
                        !$elt->isA( BalanceSets::$tidyInlineSet )
                ) {
                        // Tidy compatibility.
@@ -727,15 +732,16 @@ class BalanceStack implements IteratorAggregate {
                }
                if (
                        $this->fosterParentMode &&
-                       $this->currentNode()->isA( BalanceSets::$tableSectionRowSet )
+                       $this->currentNode->isA( BalanceSets::$tableSectionRowSet )
                ) {
                        $elt = $this->fosterParent( $elt );
                } else {
-                       $this->currentNode()->appendChild( $elt );
+                       $this->currentNode->appendChild( $elt );
                }
                Assert::invariant( $elt->parent !== null, "$elt must be in tree" );
                Assert::invariant( $elt->parent !== 'flat', "$elt must not have been previous flattened" );
                array_push( $this->elements, $elt );
+               $this->currentNode = $elt;
                return $elt;
        }
 
@@ -809,32 +815,22 @@ class BalanceStack implements IteratorAggregate {
                        BalanceSets::$thoroughImpliedEndTagsSet :
                        BalanceSets::$impliedEndTagsSet;
                while ( $this->length() > 0 ) {
-                       if ( $butnot !== null && $this->currentNode()->isA( $butnot ) ) {
+                       if ( $butnot !== null && $this->currentNode->isA( $butnot ) ) {
                                break;
                        }
-                       if ( !$this->currentNode()->isA( $endTagSet ) ) {
+                       if ( !$this->currentNode->isA( $endTagSet ) ) {
                                break;
                        }
                        $this->pop();
                }
        }
 
-       /**
-        * Return the current node (the element in the stack with the largest
-        * index).
-        * @return BalanceElement
-        * @see https://html.spec.whatwg.org/multipage/syntax.html#current-node
-        */
-       public function currentNode() {
-               return $this->node( count( $this->elements ) - 1 );
-       }
-
        /**
         * Return the adjusted current node.
         */
        public function adjustedCurrentNode( $fragmentContext ) {
                return ( $fragmentContext && $this->length() === 1 ) ?
-                       $fragmentContext : $this->currentNode();
+                       $fragmentContext : $this->currentNode;
        }
 
        /**
@@ -872,6 +868,9 @@ class BalanceStack implements IteratorAggregate {
                        'New element should not have already been flattened.'
                );
                $this->elements[$idx] = $elt;
+               if ( $idx === count( $this->elements ) - 1 ) {
+                       $this->currentNode = $elt;
+               }
        }
 
        /**
@@ -903,6 +902,11 @@ class BalanceStack implements IteratorAggregate {
         */
        public function pop() {
                $elt = array_pop( $this->elements );
+               if ( count( $this->elements ) ) {
+                       $this->currentNode = $this->elements[ count( $this->elements ) - 1 ];
+               } else {
+                       $this->currentNode = null;
+               }
                if ( !$elt->isA( 'mw:p-wrap' ) ) {
                        $elt->flatten( $this->tidyCompat );
                }
@@ -927,7 +931,7 @@ class BalanceStack implements IteratorAggregate {
         */
        public function popTag( $tag ) {
                while ( $this->length() > 0 ) {
-                       if ( $this->currentNode()->isA( $tag ) ) {
+                       if ( $this->currentNode->isA( $tag ) ) {
                                $this->pop();
                                break;
                        }
@@ -943,7 +947,7 @@ class BalanceStack implements IteratorAggregate {
        public function clearToContext( $set ) {
                // Note that we don't loop to 0. Never pop the <html> elt off.
                while ( $this->length() > 1 ) {
-                       if ( $this->currentNode()->isA( $set ) ) {
+                       if ( $this->currentNode->isA( $set ) ) {
                                break;
                        }
                        $this->pop();
@@ -971,6 +975,9 @@ class BalanceStack implements IteratorAggregate {
                $idx = array_search( $elt, $this->elements, true );
                Assert::parameter( $idx !== false, '$elt', 'must be in stack' );
                array_splice( $this->elements, $idx, 1 );
+               if ( $idx === count( $this->elements ) ) {
+                       $this->currentNode = $this->elements[$idx - 1];
+               }
                if ( $flatten ) {
                        // serialize $elt into its parent
                        // otherwise, it will eventually serialize when the parent
@@ -994,7 +1001,12 @@ class BalanceStack implements IteratorAggregate {
                Assert::parameterType( 'MediaWiki\Tidy\BalanceElement', $b, '$b' );
                $idx = $this->indexOf( $a );
                Assert::parameter( $idx !== false, '$a', 'must be in stack' );
-               array_splice( $this->elements, $idx + 1, 0, [ $b ] );
+               if ( $idx === count( $this->elements ) - 1 ) {
+                       array_push( $this->elements, $b );
+                       $this->currentNode = $b;
+               } else {
+                       array_splice( $this->elements, $idx + 1, 0, [ $b ] );
+               }
        }
 
        # Fostering and adoption.
@@ -1073,8 +1085,8 @@ class BalanceStack implements IteratorAggregate {
                // elements, then pop the current node off the stack of open
                // elements and abort these steps.
                if (
-                       $this->currentNode()->isA( $tag ) &&
-                       !$afe->isInList( $this->currentNode() )
+                       $this->currentNode->isA( $tag ) &&
+                       !$afe->isInList( $this->currentNode )
                ) {
                        $this->pop();
                        return true; // no more handling required
@@ -1939,7 +1951,7 @@ class Balancer {
                                }
                                while ( true ) {
                                        $this->stack->pop();
-                                       $node = $this->stack->currentNode();
+                                       $node = $this->stack->currentNode;
                                        if (
                                                $node->isMathmlTextIntegrationPoint() ||
                                                $node->isHtmlIntegrationPoint() ||
@@ -1952,7 +1964,7 @@ class Balancer {
                        }
                        // "Any other start tag"
                        $adjusted = ( $this->fragmentContext && $this->stack->length()===1 ) ?
-                               $this->fragmentContext : $this->stack->currentNode();
+                               $this->fragmentContext : $this->stack->currentNode;
                        $this->stack->insertForeignElement(
                                $adjusted->namespaceURI, $value, $attribs
                        );
@@ -2300,7 +2312,7 @@ class Balancer {
                                if ( $this->stack->inButtonScope( 'p' ) ) {
                                        $this->inBodyMode( 'endtag', 'p' );
                                }
-                               if ( $this->stack->currentNode()->isA( BalanceSets::$headingSet ) ) {
+                               if ( $this->stack->currentNode->isA( BalanceSets::$headingSet ) ) {
                                        $this->stack->pop();
                                }
                                $this->stack->insertHTMLElement( $value, $attribs );
@@ -2501,7 +2513,7 @@ class Balancer {
 
                        case 'optgroup':
                        case 'option':
-                               if ( $this->stack->currentNode()->isA( 'option' ) ) {
+                               if ( $this->stack->currentNode->isA( 'option' ) ) {
                                        $this->inBodyMode( 'endtag', 'option' );
                                }
                                $this->afe->reconstruct( $this->stack );
@@ -2714,7 +2726,7 @@ class Balancer {
                if ( $token === 'text' ) {
                        if ( $this->textIntegrationMode ) {
                                return $this->inBodyMode( $token, $value, $attribs, $selfclose );
-                       } elseif ( $this->stack->currentNode()->isA( BalanceSets::$tableSectionRowSet ) ) {
+                       } elseif ( $this->stack->currentNode->isA( BalanceSets::$tableSectionRowSet ) ) {
                                $this->pendingTableText = '';
                                $this->originalInsertionMode = $this->parseMode;
                                return $this->switchModeAndReprocess( 'inTableTextMode', $token, $value, $attribs, $selfclose );
@@ -2911,7 +2923,7 @@ class Balancer {
                } elseif ( $token === 'endtag' ) {
                        switch ( $value ) {
                        case 'colgroup':
-                               if ( !$this->stack->currentNode()->isA( 'colgroup' ) ) {
+                               if ( !$this->stack->currentNode->isA( 'colgroup' ) ) {
                                        return true; // Ignore the token.
                                }
                                $this->stack->pop();
@@ -2928,7 +2940,7 @@ class Balancer {
                }
 
                // Anything else
-               if ( !$this->stack->currentNode()->isA( 'colgroup' ) ) {
+               if ( !$this->stack->currentNode->isA( 'colgroup' ) ) {
                        return true; // Ignore the token.
                }
                $this->inColumnGroupMode( 'endtag', 'colgroup' );