1 files changed, 168 insertions, 0 deletions
diff --git a/org.eclipse.egit.core/src/org/eclipse/egit/core/op/BranchOperation.java b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/BranchOperation.java
new file mode 100644
index 0000000000..7c50dff319
--- /dev/null
+++ b/org.eclipse.egit.core/src/org/eclipse/egit/core/op/BranchOperation.java
@@ -0,0 +1,168 @@
+/*******************************************************************************
+ * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
+ * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
+ * Copyright (C) 2006, Shawn O. Pearce <spearce@spearce.org>
+ *
+ * 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
+ *******************************************************************************/
+package org.eclipse.egit.core.op;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+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.team.core.TeamException;
+import org.eclipse.jgit.errors.CheckoutConflictException;
+import org.eclipse.jgit.lib.Commit;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.GitIndex;
+import org.eclipse.jgit.lib.RefLogWriter;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.Tree;
+import org.eclipse.jgit.lib.WorkDirCheckout;
+
+/**
+ * This class implements checkouts of a specific revision. A check
+ * is made that this can be done without data loss.
+ */
+public class BranchOperation implements IWorkspaceRunnable {
+
+	private final Repository repository;
+
+	private final String refName;
+
+	/**
+	 * Construct a {@link BranchOperation} object.
+	 * @param repository
+	 * @param refName Name of git ref to checkout
+	 */
+	public BranchOperation(Repository repository, String refName) {
+		this.repository = repository;
+		this.refName = refName;
+	}
+
+	private Tree oldTree;
+
+	private GitIndex index;
+
+	private Tree newTree;
+	
+	private Commit oldCommit;
+
+	private Commit newCommit;
+
+
+
+	public void run(IProgressMonitor monitor) throws CoreException {
+		lookupRefs();
+		monitor.worked(1);
+
+		mapObjects();
+		monitor.worked(1);
+
+		checkoutTree();
+		monitor.worked(1);
+
+		writeIndex();
+		monitor.worked(1);
+
+		updateHeadRef();
+		monitor.worked(1);
+
+		writeHeadReflog();
+		monitor.worked(1);
+
+		refreshProjects();
+		monitor.worked(1);
+
+		monitor.done();
+	}
+
+	private void refreshProjects() {
+		final IProject[] projects = ResourcesPlugin.getWorkspace().getRoot()
+				.getProjects();
+		final File parentFile = repository.getWorkDir();
+		for (IProject p : projects) {
+			final File file = p.getLocation().toFile();
+			if (file.getAbsolutePath().startsWith(parentFile.getAbsolutePath())) {
+				try {
+					System.out.println("Refreshing " + p);
+					p.refreshLocal(IResource.DEPTH_INFINITE, null);
+				} catch (CoreException e) {
+					e.printStackTrace();
+				}
+			}
+		}
+	}
+
+	private void writeHeadReflog() throws TeamException {
+		try {
+			RefLogWriter.writeReflog(repository, oldCommit.getCommitId(),
+					newCommit.getCommitId(), "checkout: moving to " + refName,
+					Constants.HEAD);
+		} catch (IOException e) {
+			throw new TeamException("Writing HEAD's reflog", e);
+		}
+	}
+
+	private void updateHeadRef() throws TeamException {
+		try {
+			repository.writeSymref(Constants.HEAD, refName);
+		} catch (IOException e) {
+			throw new TeamException("Updating HEAD to ref: " + refName, e);
+		}
+	}
+
+	private void writeIndex() throws TeamException {
+		try {
+			index.write();
+		} catch (IOException e) {
+			throw new TeamException("Writing index", e);
+		}
+	}
+
+	private void checkoutTree() throws TeamException {
+		try {
+			new WorkDirCheckout(repository, repository.getWorkDir(), oldTree,
+					index, newTree).checkout();
+		} catch (CheckoutConflictException e) {
+			TeamException teamException = new TeamException(e.getMessage());
+			throw teamException;
+		} catch (IOException e) {
+			throw new TeamException("Problem while checking out:", e);
+		}
+	}
+
+	private void mapObjects() throws TeamException {
+		try {
+			oldTree = oldCommit.getTree();
+			index = repository.getIndex();
+			newTree = newCommit.getTree();
+		} catch (IOException e) {
+			throw new TeamException("Mapping trees", e);
+		}
+	}
+
+	private void lookupRefs() throws TeamException {
+		try {
+			newCommit = repository.mapCommit(refName);
+		} catch (IOException e) {
+			throw new TeamException("Mapping commit: " + refName, e);
+		}
+
+		try {
+			oldCommit = repository.mapCommit(Constants.HEAD);
+		} catch (IOException e) {
+			throw new TeamException("Mapping commit HEAD commit", e);
+		}
+	}
+
+}