From 669d04a686418541f83a1936d4b278721ec986fe Mon Sep 17 00:00:00 2001
From: Florian Apolloner <florian@apolloner.eu>
Date: Fri, 23 Sep 2016 10:48:02 +0200
Subject: [PATCH] Massively speed up CMakeProject::buildTree

This is done by updating folders once and not per file.

Task-number: QTCREATORBUG-16930
Change-Id: I6c1959031e7ad774cfd22c7364c88e1d0bd32962
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>
---
 .../cmakeprojectmanager/cmakeproject.cpp        | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/plugins/cmakeprojectmanager/cmakeproject.cpp b/src/plugins/cmakeprojectmanager/cmakeproject.cpp
index ab6673ed3bd..a2a6e9b4c92 100644
--- a/src/plugins/cmakeprojectmanager/cmakeproject.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakeproject.cpp
@@ -444,18 +444,27 @@ void CMakeProject::buildTree(CMakeProjectNode *rootNode, QList<ProjectExplorer::
 
     qDeleteAll(ProjectExplorer::subtractSortedList(newList, added, sortNodesByPath));
 
+    QHash<ProjectExplorer::FolderNode *, QList<ProjectExplorer::FileNode *> > addedFolderMapping;
+    QHash<ProjectExplorer::FolderNode *, QList<ProjectExplorer::FileNode *> > deletedFolderMapping;
+
     // add added nodes
     foreach (ProjectExplorer::FileNode *fn, added) {
         // Get relative path to rootNode
         QString parentDir = fn->filePath().toFileInfo().absolutePath();
         ProjectExplorer::FolderNode *folder = findOrCreateFolder(rootNode, parentDir);
-        folder->addFileNodes(QList<ProjectExplorer::FileNode *>()<< fn);
+        addedFolderMapping[folder] << fn;
     }
 
+    for (auto i = addedFolderMapping.constBegin(); i != addedFolderMapping.constEnd(); ++i)
+        i.key()->addFileNodes(i.value());
+
     // remove old file nodes and check whether folder nodes can be removed
-    foreach (ProjectExplorer::FileNode *fn, deleted) {
-        ProjectExplorer::FolderNode *parent = fn->parentFolderNode();
-        parent->removeFileNodes(QList<ProjectExplorer::FileNode *>() << fn);
+    foreach (ProjectExplorer::FileNode *fn, deleted)
+        deletedFolderMapping[fn->parentFolderNode()] << fn;
+
+    for (auto i = deletedFolderMapping.constBegin(); i != deletedFolderMapping.constEnd(); ++i) {
+        ProjectExplorer::FolderNode *parent = i.key();
+        parent->removeFileNodes(i.value());
         // Check for empty parent
         while (parent->subFolderNodes().isEmpty() && parent->fileNodes().isEmpty()) {
             ProjectExplorer::FolderNode *grandparent = parent->parentFolderNode();