speed up building of ResultTree

gui/griffon-app/models/com/muwire/gui/BrowseModel.groovy

@@ -49,7 +49,7 @@ class BrowseModel {
     private final List<TreeNode> topLevelNodes = new ArrayList<>()
     
     void mvcGroupInit(Map<String,String> args) {
-        root = new DefaultMutableTreeNode()
+        root = new ResultTreeModel.MutableResultNode()
         resultsTreeModel = new ResultTreeModel(root)
     }
     

gui/griffon-app/models/com/muwire/gui/SearchTabModel.groovy

@@ -66,7 +66,7 @@ class SearchTabModel {
     boolean treeVisible = true
     
     void mvcGroupInit(Map<String, String> args) {
-        root = new DefaultMutableTreeNode()
+        root = new ResultTreeModel.MutableResultNode()
         treeModel = new ResultTreeModel(root)
         core = mvcGroup.parentGroup.model.core
         uiSettings = application.context.get("ui-settings")

gui/src/main/groovy/com/muwire/gui/ResultTreeModel.groovy

@@ -4,6 +4,7 @@ import com.muwire.core.search.UIResultEvent
 
 import javax.swing.tree.DefaultMutableTreeNode
 import javax.swing.tree.DefaultTreeModel
+import javax.swing.tree.MutableTreeNode
 import javax.swing.tree.TreeNode
 
 class ResultTreeModel extends DefaultTreeModel {
@@ -13,10 +14,9 @@ class ResultTreeModel extends DefaultTreeModel {
     }
 
     void addToTree(UIResultEvent event) {
-        def node = root
+        MutableResultNode node = root
         if (event.path == null || event.path.length == 0) {
-            def child = new DefaultMutableTreeNode()
-            child.setUserObject(event)
+            def child = new MutableResultNode(event)
             node.add(child)
             return
         }
@@ -28,15 +28,10 @@ class ResultTreeModel extends DefaultTreeModel {
         String hiddenRoot = elements.remove(0)
         for (String element : elements) {
             def nodeData = new ResultTreeRenderer.ResultTreeNode(hiddenRoot, element)
-            def elementNode = null
-            for(int i = 0; i < node.childCount; i++) {
-                if (Objects.equals(node.getChildAt(i).getUserObject(), nodeData)) {
-                    elementNode = node.getChildAt(i)
-                    break
-                }
-            }
+            def elementNode = node.childrenMap.get(nodeData)
+            
             if (elementNode == null) {
-                elementNode = new DefaultMutableTreeNode()
+                elementNode = new MutableResultNode()
                 elementNode.setUserObject(nodeData)
                 node.add(elementNode)
             }
@@ -44,8 +39,35 @@ class ResultTreeModel extends DefaultTreeModel {
             node = elementNode
         }
 
-        def fileNode = new DefaultMutableTreeNode()
-        fileNode.setUserObject(event)
+        def fileNode = new MutableResultNode(event)
         node.add(fileNode)
     }
+    
+    static class MutableResultNode extends DefaultMutableTreeNode {
+        private final Map<Object, MutableResultNode> childrenMap
+        MutableResultNode() {
+            super()
+            childrenMap = new HashMap<>()
+        }
+        
+        MutableResultNode(UIResultEvent event) {
+            super()
+            childrenMap = Collections.emptyMap()
+            setUserObject(event)
+        }
+
+        @Override
+        void removeAllChildren() {
+            if (!childrenMap.isEmpty())
+                childrenMap.clear()
+            super.removeAllChildren()
+        }
+
+        @Override
+        void add(MutableTreeNode newChild) {
+            MutableResultNode mrn = (MutableResultNode) newChild
+            childrenMap.put(mrn.getUserObject(), mrn)
+            super.add(newChild)
+        }
+    }
 }

gui/src/main/groovy/com/muwire/gui/ResultTreeRenderer.groovy

@@ -5,6 +5,7 @@ import com.muwire.core.search.UIResultEvent
 import com.muwire.core.util.DataUtil
 import net.i2p.data.DataHelper
 
+import javax.swing.tree.DefaultMutableTreeNode
 import java.util.function.Predicate
 
 import static com.muwire.gui.Translator.trans
@@ -61,11 +62,13 @@ class ResultTreeRenderer extends DefaultTreeCellRenderer {
     
     public static class ResultTreeNode {
         private final String hiddenRoot, element
+        private final int hashCode
         private int files
         private long size
         ResultTreeNode(String hiddenRoot, String element) {
             this.hiddenRoot = hiddenRoot
             this.element = element
+            this.hashCode = Objects.hash(hiddenRoot, element)
         }
         
         private String getToolTip() {
@@ -82,6 +85,10 @@ class ResultTreeRenderer extends DefaultTreeCellRenderer {
             size += event.size
         }
         
+        public int hashCode() {
+            hashCode
+        }
+        
         public boolean equals(Object o) {
             if (!(o instanceof ResultTreeNode))
                 return false