Initial EGit contribution to eclipse.org

Per CQ 3393 this is the initial contribution of the EGit project
(an Eclipse team provider for Git) to eclipse.org.  This initial
version is derived from the historial EGit repository at commit
a9578ba7361b66ab403c6605a1b87fb7b2f94c6e.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

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);
+		}
+	}
+
+}