Bug 152919 [Import/Export] import existing project w/ copy is inefficient
I just tried to import some existing projects and selected "copy projects into workspace". After a long time (sorry, no measurements) I had to cancel the request, because I was running out of disk space. I had just succeeded in importing the first project (jdt core), which takes approx. 80MB disk space, but at that time the previously blank workspace consumed additional 300MB mainly in: .metadata/.plugins/org.eclipse.core.resources/.history/ Is this operation recording undo-information for each single file imported? Unless I made something really stupid, this operation seems not to be usable for large projects.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
final IWorkspace workspace = ResourcesPlugin.getWorkspace();
		final IProject project = workspace.getRoot().getProject(projectName);
		if (record.description == null) {
			
			record.description = workspace.newProjectDescription(projectName);
			IPath locationPath = new Path(record.projectSystemFile
					.getAbsolutePath());
			
			if (Platform.getLocation().isPrefixOf(locationPath)) {
				record.description.setLocation(null);
			} else {
				record.description.setLocation(locationPath);
			}
		} else {
			record.description.setName(projectName);
		}
		if (record.projectArchiveFile != null) {
			
			ArrayList fileSystemObjects = new ArrayList();
			getFilesForProject(fileSystemObjects, record.provider,
					record.parent);
			record.provider.setStrip(record.level);
			ImportOperation operation = new ImportOperation(project
					.getFullPath(), record.provider.getRoot(), record.provider,
					this, fileSystemObjects);
			operation.setContext(getShell());
			operation.run(monitor);
			return true;
		}