Improve DiscardChangesAction

Currently DiscardChangesAction (Trigger: Replace With->File in Git
Index) runs in the UI thread. This might block the UI. Furthermore
the discard operation is located in the action.
Now DiscardChangesAction uses a Job to execute. The discard operation
was moved in a new class DiscardChangesOperation.

Change-Id: I06fe4efa096ae4ca6b1110c2f7259243e1d2c99d
Signed-off-by: Jens Baumgart <jens.baumgart@sap.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

7 files changed, 298 insertions, 92 deletions

diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
index 1624d60d4a..9de35c94a1 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/CoreText.java
@@ -47,6 +47,24 @@ public class CoreText extends NLS {
 	public static String ConnectProviderOperation_ConnectingProject;
 
 	/** */
+	public static String DiscardChangesOperation_discardFailed;
+
+	/** */
+	public static String DiscardChangesOperation_discardFailedSeeLog;
+
+	/** */
+	public static String DiscardChangesOperation_discardingChanges;
+
+	/** */
+	public static String DiscardChangesOperation_refreshFailed;
+
+	/** */
+	public static String DiscardChangesOperation_repoNotFound;
+
+	/** */
+	public static String DiscardChangesOperation_writeIndexFailed;
+
+	/** */
 	public static String DisconnectProviderOperation_disconnecting;
 
 	/** */
@@ -191,6 +209,9 @@ public class CoreText extends NLS {
 	public static String ProjectUtil_refreshingProjects;
 
 	/** */
+	public static String ProjectUtil_refreshing;
+
+	/** */
 	public static String PushOperation_resultCancelled;
 
 	/** */
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties b/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
index 576d730b0c..1076c6400d 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/coretext.properties
@@ -12,6 +12,12 @@ CommitFileRevision_errorLookingUpPath=IO error looking up path {1} in {0}.
 ConnectProviderOperation_connecting=Connecting Git team provider.
 ConnectProviderOperation_ConnectingProject=Connecting project {0}
 
+DiscardChangesOperation_discardFailed=Discarding changes of {0} failed
+DiscardChangesOperation_discardFailedSeeLog=Discarding changes failed. See log for details
+DiscardChangesOperation_discardingChanges=Discarding changes
+DiscardChangesOperation_refreshFailed=Refreshing resources failed
+DiscardChangesOperation_repoNotFound=Repository not found
+DiscardChangesOperation_writeIndexFailed=Writing index failed
 DisconnectProviderOperation_disconnecting=Disconnecting Git team provider.
 
 UpdateJob_updatingIndex=Update index
@@ -79,6 +85,7 @@ IndexFileRevision_indexEntryNotFound=Git index entry for path {1} not found
 ListRemoteOperation_title=Getting remote branches information
 
 ProjectUtil_refreshingProjects=Refreshing projects
+ProjectUtil_refreshing=Refreshing
 PushOperation_resultCancelled=Operation was cancelled.
 PushOperation_resultNotSupported=Can't push to {0}
 PushOperation_resultTransportError=Transport error occured during push operation: {0}
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/util/ProjectUtil.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/util/ProjectUtil.java
index 246b50401b..8585f195bd 100644
--- a/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/util/ProjectUtil.java
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/internal/util/ProjectUtil.java
@@ -21,7 +21,7 @@ import org.eclipse.jgit.lib.Repository;
 
 /**
  * This class contains utility methods related to projects
- *
+ * TODO: rename to RefreshUtil or ResourceUtil?
  */
 public class ProjectUtil {
 	/**
@@ -53,4 +53,31 @@ public class ProjectUtil {
 			monitor.done();
 		}
 	}
+
+	/**
+	 * The method refreshes resources
+	 *
+	 * @param resources
+	 *            resources to refresh
+	 * @param monitor
+	 * @throws CoreException
+	 */
+	public static void refreshResources(IResource[] resources,
+			IProgressMonitor monitor) throws CoreException {
+		try {
+			monitor.beginTask(CoreText.ProjectUtil_refreshing,
+					resources.length);
+			for (IResource resource : resources) {
+				if (monitor.isCanceled())
+					break;
+				resource.refreshLocal(IResource.DEPTH_INFINITE,
+						new SubProgressMonitor(monitor, 1));
+				monitor.worked(1);
+			}
+		} finally {
+			monitor.done();
+		}
+
+	}
+
 }
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/DiscardChangesOperation.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/DiscardChangesOperation.java
new file mode 100644
index 0000000000..8dd576e148
--- /dev/null
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/DiscardChangesOperation.java
@@ -0,0 +1,212 @@
+/*******************************************************************************
+ * Copyright (C) 2010, Jens Baumgart <jens.baumgart@sap.com>
+ * Copyright (C) 2010, Roland Grunberg <rgrunber@redhat.com>
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Code extracted from org.eclipse.egit.ui.internal.actions.DiscardChangesAction
+ * and reworked.
+ *******************************************************************************/
+package org.eclipse.egit.core.op;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.eclipse.core.resources.IContainer;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.IResourceRuleFactory;
+import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.resources.IWorkspaceRunnable;
+import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.SubProgressMonitor;
+import org.eclipse.core.runtime.jobs.ISchedulingRule;
+import org.eclipse.core.runtime.jobs.MultiRule;
+import org.eclipse.egit.core.Activator;
+import org.eclipse.egit.core.CoreText;
+import org.eclipse.egit.core.internal.util.ProjectUtil;
+import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.jgit.lib.GitIndex;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.GitIndex.Entry;
+import org.eclipse.osgi.util.NLS;
+
+/**
+ * The operation discards changes on a set of resources. In case of a folder
+ * resource all file resources in the sub tree are processed.
+ */
+public class DiscardChangesOperation implements IEGitOperation {
+
+	IResource[] files;
+
+	ISchedulingRule schedulingRule;
+
+	/**
+	 * Construct a {@link DiscardChangesOperation} object.
+	 *
+	 * @param files
+	 */
+	public DiscardChangesOperation(IResource[] files) {
+		this.files = files;
+		schedulingRule = calcRefreshRule(files);
+	}
+
+	/**
+	 * @return the rule needed to execute this operation
+	 */
+	public ISchedulingRule getSchedulingRule() {
+		return schedulingRule;
+	}
+
+	private static ISchedulingRule calcRefreshRule(IResource[] resources) {
+		List<ISchedulingRule> rules = new ArrayList<ISchedulingRule>();
+		IResourceRuleFactory ruleFactory = ResourcesPlugin.getWorkspace()
+				.getRuleFactory();
+		for (IResource resource : resources) {
+			ISchedulingRule rule = ruleFactory.refreshRule(resource);
+			if (rule != null)
+				rules.add(rule);
+		}
+		if (rules.size() == 0)
+			return null;
+		else
+			return new MultiRule(rules.toArray(new IResource[rules.size()]));
+	}
+
+	public void execute(IProgressMonitor monitor) throws CoreException {
+		IWorkspaceRunnable action = new IWorkspaceRunnable() {
+			public void run(IProgressMonitor monitor) throws CoreException {
+				discardChanges(monitor);
+			}
+		};
+		ResourcesPlugin.getWorkspace().run(action, getSchedulingRule(),
+				IWorkspace.AVOID_UPDATE, monitor);
+	}
+
+	private void discardChanges(IProgressMonitor monitor) throws CoreException {
+		monitor.beginTask(CoreText.DiscardChangesOperation_discardingChanges, 3);
+		boolean errorOccured = false;
+		List<IResource> allFiles = new ArrayList<IResource>();
+		// find all files
+		for (IResource res : files) {
+			allFiles.addAll(getAllMembers(res));
+		}
+		Set<GitIndex> modifiedIndexes = new HashSet<GitIndex>();
+		for (IResource res : allFiles) {
+			Repository repo = getRepository(res);
+			if (repo == null) {
+				IStatus status = Activator.error(
+						CoreText.DiscardChangesOperation_repoNotFound, null);
+				throw new CoreException(status);
+			}
+			try {
+				discardChange(res, repo, modifiedIndexes);
+			} catch (IOException e) {
+				errorOccured = true;
+				String message = NLS.bind(
+						CoreText.DiscardChangesOperation_discardFailed, res
+								.getFullPath());
+				Activator.logError(message, e);
+			}
+		}
+		monitor.worked(1);
+		for (GitIndex index : modifiedIndexes) {
+			try {
+				index.write();
+			} catch (IOException e) {
+				errorOccured = true;
+				Activator.logError(
+						CoreText.DiscardChangesOperation_writeIndexFailed, e);
+			}
+		}
+		monitor.worked(1);
+		try {
+			ProjectUtil.refreshResources(files, new SubProgressMonitor(monitor,
+					1));
+		} catch (CoreException e) {
+			errorOccured = true;
+			Activator.logError(CoreText.DiscardChangesOperation_refreshFailed,
+					e);
+		}
+		monitor.worked(1);
+		monitor.done();
+		if (errorOccured) {
+			IStatus status = Activator.error(
+					CoreText.DiscardChangesOperation_discardFailedSeeLog, null);
+			throw new CoreException(status);
+		}
+	}
+
+	private static Repository getRepository(IResource resource) {
+		IProject project = resource.getProject();
+		RepositoryMapping repositoryMapping = RepositoryMapping
+				.getMapping(project);
+		if (repositoryMapping != null)
+			return repositoryMapping.getRepository();
+		else
+			return null;
+	}
+
+	private void discardChange(IResource res, Repository repository,
+			Set<GitIndex> modifiedIndexes) throws IOException {
+		String resRelPath = RepositoryMapping.getMapping(res)
+				.getRepoRelativePath(res);
+
+		Entry e = repository.getIndex().getEntry(resRelPath);
+		// resource must exist in the index and be dirty
+		if (e != null && e.getStage() == 0
+				&& e.isModified(repository.getWorkDir())) {
+			GitIndex index = repository.getIndex();
+			index.checkoutEntry(repository.getWorkDir(), e);
+			modifiedIndexes.add(index);
+		}
+	}
+
+	/**
+	 * @param res
+	 *            an IResource
+	 * @return An ArrayList with all members of this IResource of arbitrary
+	 *         depth. This will return just the argument res if it is a file.
+	 */
+	private ArrayList<IResource> getAllMembers(IResource res) {
+		ArrayList<IResource> ret = new ArrayList<IResource>();
+		if (res.getLocation().toFile().isFile()) {
+			ret.add(res);
+		} else {
+			getAllMembersHelper(res, ret);
+		}
+		return ret;
+	}
+
+	private void getAllMembersHelper(IResource res, ArrayList<IResource> ret) {
+		if (res instanceof IContainer) {
+			ArrayList<IResource> tmp = new ArrayList<IResource>();
+			IContainer cont = (IContainer) res;
+			try {
+				for (IResource r : cont.members()) {
+					if (r.getLocation().toFile().isFile()) {
+						tmp.add(r);
+					} else {
+						getAllMembersHelper(r, tmp);
+					}
+				}
+			} catch (CoreException e) {
+				// thrown by members()
+				// ignore children in case parent resource no longer accessible
+				return;
+			}
+
+			ret.addAll(tmp);
+		}
+	}
+
+}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index 2ce6989aa1..1c209074ea 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -1723,6 +1723,9 @@ public class UIText extends NLS {
 	public static String DiscardChangesAction_confirmActionMessage;
 
 	/** */
+	public static String DiscardChangesAction_discardChanges;
+
+	/** */
 	public static String DiscardChangesAction_unexpectedErrorTitle;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/DiscardChangesAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/DiscardChangesAction.java
index a169a7d57f..c2ca63efb6 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/DiscardChangesAction.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/DiscardChangesAction.java
@@ -8,27 +8,25 @@
  *******************************************************************************/
 package org.eclipse.egit.ui.internal.actions;
 
-import java.io.IOException;
-import java.util.ArrayList;
-
-import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.NullProgressMonitor;
-import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.egit.core.op.DiscardChangesOperation;
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.UIText;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RepositoryState;
-import org.eclipse.jgit.lib.GitIndex.Entry;
 
 /**
  * Checkout all selected dirty files.
  */
-public class DiscardChangesAction extends RepositoryAction{
+public class DiscardChangesAction extends RepositoryAction {
 
 	@Override
 	public void execute(IAction action) {
@@ -36,50 +34,26 @@ public class DiscardChangesAction extends RepositoryAction{
 		boolean performAction = MessageDialog.openConfirm(getShell(),
 				UIText.DiscardChangesAction_confirmActionTitle,
 				UIText.DiscardChangesAction_confirmActionMessage);
-		if (performAction) {
-			performDiscardChanges();
-		}
-	}
-
-	private void performDiscardChanges() {
-		ArrayList<IResource> allFiles = new ArrayList<IResource>();
-
-		// find all files
-		for (IResource res : getSelectedResources()) {
-			allFiles.addAll(getAllMembers(res));
-		}
-
-		for (IResource res : allFiles) {
-			try {
-				discardChange(res);
-			} catch (IOException e1) {
-				Activator.handleError(UIText.DiscardChangesAction_unexpectedErrorMessage, e1, true);
-			}catch (RuntimeException e2) {
-				Activator.handleError(UIText.DiscardChangesAction_unexpectedIndexErrorMessage, e2, true);
-			}
-		}
-
-	}
-
-	private void discardChange(IResource res) throws IOException {
-		IProject[] proj = new IProject[] { res.getProject() };
-		Repository repository = getRepositoriesFor(proj)[0];
-
-		String resRelPath = RepositoryMapping.getMapping(res).getRepoRelativePath(res);
-		Entry e = repository.getIndex().getEntry(resRelPath);
-
-		// resource must exist in the index and be dirty
-		if (e != null && e.getStage() == 0 && e.isModified(repository.getWorkDir())) {
-			repository.getIndex().checkoutEntry(repository.getWorkDir(), e);
-
-			try {
-				res.refreshLocal(0, new NullProgressMonitor());
-			} catch (CoreException e1) {
-				Activator.handleError(UIText.DiscardChangesAction_refreshErrorMessage, e1, true);
+		if (!performAction)
+			return;
+		final DiscardChangesOperation operation = new DiscardChangesOperation(
+				getSelectedResources());
+		String jobname = UIText.DiscardChangesAction_discardChanges;
+		Job job = new Job(jobname) {
+			@Override
+			protected IStatus run(IProgressMonitor monitor) {
+				try {
+					operation.execute(monitor);
+				} catch (CoreException e) {
+					return Activator.createErrorStatus(e.getStatus()
+							.getMessage(), e);
+				}
+				return Status.OK_STATUS;
 			}
-
-			repository.getIndex().write();
-		}
+		};
+		job.setUser(true);
+		job.setRule(operation.getSchedulingRule());
+		job.schedule();
 	}
 
 	@Override
@@ -87,50 +61,11 @@ public class DiscardChangesAction extends RepositoryAction{
 		for (IResource res : getSelectedResources()) {
 			IProject[] proj = new IProject[] { res.getProject() };
 			Repository repository = getRepositoriesFor(proj)[0];
-			if (! repository.getRepositoryState().equals(RepositoryState.SAFE)){
+			if (!repository.getRepositoryState().equals(RepositoryState.SAFE)) {
 				return false;
 			}
 		}
 		return true;
 	}
 
-	/**
-	 * @param res an IResource
-	 * @return An ArrayList with all members of this IResource
-	 * of arbitrary depth. This will return just the argument
-	 * res if it is a file.
-	 */
-	private ArrayList<IResource> getAllMembers(IResource res) {
-		ArrayList<IResource> ret = new ArrayList<IResource>();
-		if (res.getLocation().toFile().isFile()) {
-			ret.add(res);
-		} else {
-			getAllMembersHelper(res, ret);
-		}
-		return ret;
-	}
-
-
-	private void getAllMembersHelper(IResource res, ArrayList<IResource> ret) {
-		ArrayList<IResource> tmp = new ArrayList<IResource> ();
-		if (res instanceof IContainer) {
-			IContainer cont = (IContainer) res;
-			try {
-				for (IResource r : cont.members()) {
-					if (r.getLocation().toFile().isFile()) {
-						tmp.add(r);
-					} else {
-						getAllMembersHelper(r, tmp);
-					}
-				}
-			} catch (CoreException e) {
-				// thrown by members()
-				// ignore children in case parent resource no longer accessible
-				return;
-			}
-
-			ret.addAll(tmp);
-		}
-	}
-
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index f91a848178..6139155c6e 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -616,6 +616,7 @@ RepositoriesViewLabelProvider_TagsNodeText=Tags
 
 DiscardChangesAction_confirmActionTitle=Discard Local Changes
 DiscardChangesAction_confirmActionMessage=This will discard all local changes for the selected resources. Are you sure you want to do this ?
+DiscardChangesAction_discardChanges=Discard Changes
 DiscardChangesAction_unexpectedErrorTitle=Unexpected Error
 DiscardChangesAction_unexpectedErrorMessage=An unexpected error occured while attempting to checkout resources.
 DiscardChangesAction_unexpectedIndexErrorMessage=An unexpected error occured while attempting to interact with the Git Index.