### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core.tests.performance
Index: src/org/eclipse/jdt/core/tests/performance/FullSourceWorkspaceModelTests.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.performance/src/org/eclipse/jdt/core/tests/performance/FullSourceWorkspaceModelTests.java,v
retrieving revision 1.23
diff -u -r1.23 FullSourceWorkspaceModelTests.java
--- src/org/eclipse/jdt/core/tests/performance/FullSourceWorkspaceModelTests.java	2 Apr 2007 07:28:54 -0000	1.23
+++ src/org/eclipse/jdt/core/tests/performance/FullSourceWorkspaceModelTests.java	18 Apr 2007 11:55:11 -0000
@@ -854,6 +854,48 @@
 	}
 }
 
+/*
+ * Performance test for the first use of findType(...)
+ * (see bug 161175 JarPackageFragmentRoot slow to initialize)
+ */
+public void testFindType() throws CoreException {
+	// get 20 projects
+	IJavaModel model = JavaCore.create(ResourcesPlugin.getWorkspace().getRoot());
+	IJavaProject[] allProjects = model.getJavaProjects();
+	int max = 20;
+	IJavaProject[] projects = new IJavaProject[max];
+	int index = 0;
+	for (int i = 0, length = allProjects.length; i < length; i++) {
+		if (allProjects[i].getElementName().startsWith("org.eclipse")) {
+			projects[index++] = allProjects[i];
+			if (index == max)
+				break;
+		}
+	}
+	
+	// warm up
+	for (int i = 0; i < 5; i++) {
+		model.close();
+		for (int j = 0; j < max; j++) {
+			projects[j].findType("java.lang.Object");
+		}
+	}
+		
+	// measure performance
+	for (int i = 0; i < 10; i++) {
+		model.close();
+		runGc();
+		startMeasuring();
+		for (int j = 0; j < max; j++) {
+			projects[j].findType("java.lang.Object");
+		}
+		stopMeasuring();
+	}
+
+	commitMeasurements();
+	assertPerformance();
+}
+
 public void testStartJDTPlugin() throws JavaModelException {
 	// store current settings
 	long oldSnapInterval = ENV.getWorkspace().getDescription().getSnapshotInterval();	
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/JavaProjectElementInfo.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/JavaProjectElementInfo.java,v
retrieving revision 1.44
diff -u -r1.44 JavaProjectElementInfo.java
--- model/org/eclipse/jdt/internal/core/JavaProjectElementInfo.java	13 Apr 2007 16:02:15 -0000	1.44
+++ model/org/eclipse/jdt/internal/core/JavaProjectElementInfo.java	18 Apr 2007 11:55:12 -0000
@@ -206,13 +206,23 @@
 				roots = new IPackageFragmentRoot[0];
 				reverseMap.clear();
 			}
+			
+			DeltaProcessingState deltaState = JavaModelManager.getJavaModelManager().deltaState;
+			HashMap otherRoots = deltaState.oldOtherRoots;
+			if (otherRoots == null) {
+				deltaState.initializeRoots();
+				otherRoots = deltaState.otherRoots;
+			}
+				
 			HashtableOfArrayToObject fragmentsCache = new HashtableOfArrayToObject();
 			HashtableOfArrayToObject isPackageCache = new HashtableOfArrayToObject();
 			for (int i = 0, length = roots.length; i < length; i++) {
 				IPackageFragmentRoot root = roots[i];
 				IJavaElement[] frags = null;
 				try {
-					if (root.isArchive() && !root.isOpen()) {
+					if (root.isArchive() 
+							&& !root.isOpen() 
+							&& otherRoots.get(((JarPackageFragmentRoot) root).jarPath) == null/*only if jar belongs to 1 project (https://bugs.eclipse.org/bugs/show_bug.cgi?id=161175)*/) {
 						JarPackageFragmentRootInfo info = new JarPackageFragmentRootInfo();
 						((JarPackageFragmentRoot) root).computeChildren(info, new HashMap());
 						frags = info.children;