Patch for QDom

qdom-cache-ariya.patch

Index: qdom.cpp
===================================================================
--- qdom.cpp	(revision 599821)
+++ qdom.cpp	(working copy)
@@ -40,6 +40,15 @@
 #include <qdebug.h>
 #include <stdio.h>
 
+/**
+  Additional feature by Ariya Hidayat ([email protected])
+  
+  If this is defined, QDom tries to cache as many strings as possible. 
+  Because QString is implicity shared, this reduced memory comsumption 
+  for a very large XML document, e.g. files in OpenDocument format.
+  */
+#define QDOM_CACHE_STRING 1  
+
 /*
   ### old todo comments -- I don't know if they still apply...
 
@@ -520,6 +529,25 @@
     // Variables
     QDomImplementationPrivate* impl;
     QDomDocumentTypePrivate* type;
+    
+    // To cache tag name, prefix, attribute name
+#ifdef QDOM_CACHE_STRING    
+    QMap<QString,int> stringHash;
+    QStringList stringList;
+    QString cacheString(const QString& str)
+    {
+        const int& ii = stringHash[str];
+        if(ii > 0)
+            return stringList.at( ii );
+
+        // not yet declared, so we add it
+        int i = stringList.count();
+        stringList.append( str );
+        stringHash.insert( str, i );
+  
+        return str;
+    }
+#endif    
 };
 
 /**************************************************************
@@ -4533,17 +4561,22 @@
 {
     QString prefix, localName;
     qt_split_namespace(prefix, localName, qName, true);
+#ifdef QDOM_CACHE_STRING
+    QString val = ownerDocument()->cacheString(newValue);
+#else
+    QString val = newValue;
+#endif
     QDomNodePrivate* n = m_attr->namedItemNS(nsURI, localName);
     if (!n) {
         n = new QDomAttrPrivate(ownerDocument(), this, nsURI, qName);
-        n->setNodeValue(newValue);
+        n->setNodeValue(val);
 
         // Referencing is done by the map, so we set the reference counter back
         // to 0 here. This is ok since we created the QDomAttrPrivate.
         n->ref.deref();
         m_attr->setNamedItem(n);
     } else {
-        n->setNodeValue(newValue);
+        n->setNodeValue(val);
         n->prefix = prefix;
     }
 }
@@ -6231,6 +6264,10 @@
         delete type;
     impl = 0;
     type = 0;
+#ifdef QDOM_CACHE_STRING
+    stringHash.clear();
+    stringList.clear();
+#endif
     QDomNodePrivate::clear();
 }
 
@@ -6296,7 +6333,11 @@
     QString fixedName = fixedXmlName(tagName, &ok);
     if (!ok)
         return 0;
-
+        
+#ifdef QDOM_CACHE_STRING        
+    fixedName = cacheString(fixedName);
+#endif
+        
     QDomElementPrivate *e = new QDomElementPrivate(this, 0, fixedName);
     e->ref.deref();
     return e;
@@ -6309,7 +6350,14 @@
     if (!ok)
         return 0;
 
-    QDomElementPrivate *e = new QDomElementPrivate(this, 0, nsURI, fixedName);
+#ifdef QDOM_CACHE_STRING        
+    fixedName = cacheString(fixedName);
+    QString ns = cacheString(nsURI);
+#else
+    QString ns = nsURI;
+#endif
+
+    QDomElementPrivate *e = new QDomElementPrivate(this, 0, ns, fixedName);
     e->ref.deref();
     return e;
 }
@@ -6383,6 +6431,10 @@
     if (!ok)
         return 0;
 
+#ifdef QDOM_CACHE_STRING        
+    fixedName = cacheString(fixedName);
+#endif
+        
     QDomAttrPrivate *a = new QDomAttrPrivate(this, 0, fixedName);
     a->ref.deref();
     return a;
@@ -6395,7 +6447,14 @@
     if (!ok)
         return 0;
 
-    QDomAttrPrivate *a = new QDomAttrPrivate(this, 0, nsURI, fixedName);
+#ifdef QDOM_CACHE_STRING        
+    fixedName = cacheString(fixedName);
+    QString ns = cacheString(nsURI);
+#else
+    QString ns = nsURI;
+#endif
+        
+    QDomAttrPrivate *a = new QDomAttrPrivate(this, 0, ns, fixedName);
     a->ref.deref();
     return a;
 }