Bug 959150 part 5 - Avoid reallocating the attribute holder when parsing with nsHtml5StringParser. r=smaug.

parser/html/javasrc/Tokenizer.java

@@ -497,12 +497,12 @@ public class Tokenizer implements Locator {
 
     private boolean html4ModeCompatibleWithXhtml1Schemata;
 
-    private final boolean newAttributesEachTime;
-
     private int mappingLangToXmlLang;
 
     // ]NOCPP]
 
+    private final boolean newAttributesEachTime;
+
     private boolean shouldSuspend;
 
     protected boolean confident;
@@ -554,8 +554,12 @@ public class Tokenizer implements Locator {
         this.doctypeName = null;
         this.publicIdentifier = null;
         this.systemIdentifier = null;
+        // [NOCPP[
         this.attributes = null;
-    // CPPONLY: this.viewingXmlSource = viewingXmlSource;
+        // ]NOCPP]
+        // CPPONLY: this.attributes = tokenHandler.HasBuilder() ? new HtmlAttributes(mappingLangToXmlLang) : null;
+        // CPPONLY: this.newAttributesEachTime = !tokenHandler.HasBuilder();
+        // CPPONLY: this.viewingXmlSource = viewingXmlSource;
     }
 
     public void setInterner(Interner interner) {
@@ -1096,21 +1100,6 @@ public class Tokenizer implements Locator {
         errorHandler.warning(spe);
     }
 
-    /**
-     * 
-     */
-    private void resetAttributes() {
-        // [NOCPP[
-        if (newAttributesEachTime) {
-            // ]NOCPP]
-            attributes = null;
-            // [NOCPP[
-        } else {
-            attributes.clear(mappingLangToXmlLang);
-        }
-        // ]NOCPP]
-    }
-
     private void strBufToElementNameString() {
         // if (strBufOffset != -1) {
         // return ElementName.elementNameByBuffer(buf, strBufOffset, strBufLen);
@@ -1136,17 +1125,26 @@ public class Tokenizer implements Locator {
             // CPPONLY: if (!viewingXmlSource) {
             tokenHandler.endTag(tagName);
             // CPPONLY: }
-            Portability.delete(attributes);
+            // CPPONLY: if (newAttributesEachTime) {
+            // CPPONLY:   Portability.delete(attributes);
+            // CPPONLY:   attributes = null;
+            // CPPONLY: }
         } else {
             // CPPONLY: if (viewingXmlSource) {
-            // CPPONLY: Portability.delete(attributes);
+            // CPPONLY:   assert newAttributesEachTime;
+            // CPPONLY:   Portability.delete(attributes);
+            // CPPONLY:   attributes = null;
             // CPPONLY: } else {
             tokenHandler.startTag(tagName, attrs, selfClosing);
             // CPPONLY: }
         }
         tagName.release();
         tagName = null;
-        resetAttributes();
+        if (newAttributesEachTime) {
+            attributes = null;
+        } else {
+            attributes.clear(mappingLangToXmlLang);
+        }
         /*
          * The token handler may have called setStateAndEndTagExpectation
          * and changed stateSave since the start of this method.
@@ -6597,11 +6595,11 @@ public class Tokenizer implements Locator {
             attributeName = null;
         }
         tokenHandler.endTokenization();
+        // [NOCPP[
         if (attributes != null) {
-            attributes.clear(mappingLangToXmlLang);
-            Portability.delete(attributes);
             attributes = null;
         }
+        // ]NOCPP]
     }
 
     public void requestSuspension() {
@@ -6680,16 +6678,12 @@ public class Tokenizer implements Locator {
             attributeName.release();
             attributeName = null;
         }
-        // [NOCPP[
         if (newAttributesEachTime) {
-            // ]NOCPP]
             if (attributes != null) {
                 Portability.delete(attributes);
                 attributes = null;
             }
-            // [NOCPP[
         }
-        // ]NOCPP]
     }
 
     public void loadState(Tokenizer other) throws SAXException {
@@ -7005,6 +6999,8 @@ public class Tokenizer implements Locator {
     
     void destructor() {
         // The translator will write refcount tracing stuff here
+        Portability.delete(attributes);
+        attributes = null;
     }
     
     // [NOCPP[

parser/html/javasrc/TreeBuilder.java

@@ -3027,9 +3027,9 @@ public abstract class TreeBuilder<T> implements TokenHandler,
         if (selfClosing) {
             errSelfClosing();
         }
-        if (attributes != HtmlAttributes.EMPTY_ATTRIBUTES) {
-            Portability.delete(attributes);
-        }
+        // CPPONLY: if (mBuilder == null && attributes != HtmlAttributes.EMPTY_ATTRIBUTES) {
+        // CPPONLY:    Portability.delete(attributes);
+        // CPPONLY: }
     }
 
     private void startTagTitleInHead(ElementName elementName, HtmlAttributes attributes) throws SAXException {

parser/html/nsHtml5Tokenizer.cpp

@@ -98,7 +98,8 @@ nsHtml5Tokenizer::nsHtml5Tokenizer(nsHtml5TreeBuilder* tokenHandler, bool viewin
     doctypeName(nullptr),
     publicIdentifier(nullptr),
     systemIdentifier(nullptr),
-    attributes(nullptr),
+    attributes(tokenHandler->HasBuilder() ? new nsHtml5HtmlAttributes(0) : nullptr),
+    newAttributesEachTime(!tokenHandler->HasBuilder()),
     viewingXmlSource(viewingXmlSource)
 {
   MOZ_COUNT_CTOR(nsHtml5Tokenizer);
@@ -283,12 +284,6 @@ nsHtml5Tokenizer::flushChars(char16_t* buf, int32_t pos)
   cstart = INT32_MAX;
 }
 
-void 
-nsHtml5Tokenizer::resetAttributes()
-{
-  attributes = nullptr;
-}
-
 void 
 nsHtml5Tokenizer::strBufToElementNameString()
 {
@@ -307,17 +302,26 @@ nsHtml5Tokenizer::emitCurrentTagToken(bool selfClosing, int32_t pos)
     if (!viewingXmlSource) {
       tokenHandler->endTag(tagName);
     }
-    delete attributes;
+    if (newAttributesEachTime) {
+      delete attributes;
+      attributes = nullptr;
+    }
   } else {
     if (viewingXmlSource) {
+      MOZ_ASSERT(newAttributesEachTime);
       delete attributes;
+      attributes = nullptr;
     } else {
       tokenHandler->startTag(tagName, attrs, selfClosing);
     }
   }
   tagName->release();
   tagName = nullptr;
-  resetAttributes();
+  if (newAttributesEachTime) {
+    attributes = nullptr;
+  } else {
+    attributes->clear(0);
+  }
   return stateSave;
 }
 
@@ -3932,11 +3936,6 @@ nsHtml5Tokenizer::end()
     attributeName = nullptr;
   }
   tokenHandler->endTokenization();
-  if (attributes) {
-    attributes->clear(0);
-    delete attributes;
-    attributes = nullptr;
-  }
 }
 
 void 
@@ -3981,9 +3980,11 @@ nsHtml5Tokenizer::resetToDataState()
     attributeName->release();
     attributeName = nullptr;
   }
-  if (attributes) {
-    delete attributes;
-    attributes = nullptr;
+  if (newAttributesEachTime) {
+    if (attributes) {
+      delete attributes;
+      attributes = nullptr;
+    }
   }
 }
 
@@ -4080,6 +4081,8 @@ nsHtml5Tokenizer::setEncodingDeclarationHandler(nsHtml5StreamParser* encodingDec
 nsHtml5Tokenizer::~nsHtml5Tokenizer()
 {
   MOZ_COUNT_DTOR(nsHtml5Tokenizer);
+  delete attributes;
+  attributes = nullptr;
 }
 
 void

parser/html/nsHtml5Tokenizer.h

@@ -130,6 +130,7 @@ class nsHtml5Tokenizer
     nsString* publicIdentifier;
     nsString* systemIdentifier;
     nsHtml5HtmlAttributes* attributes;
+    bool newAttributesEachTime;
     bool shouldSuspend;
   protected:
     bool confident;
@@ -206,7 +207,6 @@ class nsHtml5Tokenizer
   protected:
     void flushChars(char16_t* buf, int32_t pos);
   private:
-    void resetAttributes();
     void strBufToElementNameString();
     int32_t emitCurrentTagToken(bool selfClosing, int32_t pos);
     void attributeNameComplete();

parser/html/nsHtml5TokenizerHSupplement.h

@@ -2,6 +2,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+inline nsHtml5HtmlAttributes* GetAttributes()
+{
+  return attributes;
+}
+
 nsAutoPtr<nsHtml5Highlighter> mViewSource;
 
 /**

parser/html/nsHtml5TreeBuilder.cpp

@@ -1890,7 +1890,7 @@ nsHtml5TreeBuilder::startTag(nsHtml5ElementName* elementName, nsHtml5HtmlAttribu
   if (selfClosing) {
     errSelfClosing();
   }
-  if (attributes != nsHtml5HtmlAttributes::EMPTY_ATTRIBUTES) {
+  if (!mBuilder && attributes != nsHtml5HtmlAttributes::EMPTY_ATTRIBUTES) {
     delete attributes;
   }
 }

parser/html/nsHtml5TreeBuilderCppSupplement.h

@@ -81,7 +81,8 @@ nsHtml5TreeBuilder::createElement(int32_t aNamespace, nsIAtom* aName, nsHtml5Htm
                                           aAttributes,
                                           mozilla::dom::FROM_PARSER_FRAGMENT,
                                           mBuilder);
-    if (aAttributes != nsHtml5HtmlAttributes::EMPTY_ATTRIBUTES) {
+    if (MOZ_UNLIKELY(aAttributes != tokenizer->GetAttributes() &&
+                     aAttributes != nsHtml5HtmlAttributes::EMPTY_ATTRIBUTES)) {
       delete aAttributes;
     }
     return elem;
@@ -511,6 +512,8 @@ nsHtml5TreeBuilder::addAttributesToElement(nsIContentHandle* aElement, nsHtml5Ht
   }
 
   if (mBuilder) {
+    MOZ_ASSERT(aAttributes == tokenizer->GetAttributes(),
+      "Using attribute other than the tokenizer's to add to body or html.");
     nsresult rv = nsHtml5TreeOperation::AddAttributes(
       static_cast<nsIContent*>(aElement),
       aAttributes,

parser/html/nsHtml5TreeBuilderHSupplement.h

@@ -119,6 +119,10 @@
       mPreventScriptExecution = aPrevent;
     }
 
+    bool HasBuilder() {
+      return mBuilder;
+    }
+
     void EnableViewSource(nsHtml5Highlighter* aHighlighter);
 
     void errStrayStartTag(nsIAtom* aName);