Add methods to Repository to handle remote names

Instead of requiring the caller to know how to list remote
names or parse remote branch names, add a few utilities for
that.

Change-Id: Ib6b2403532f4abbce594a03c0b9da49d30b19f70
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RefTest.java

@@ -58,9 +58,11 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.Map;
+import java.util.TreeSet;
 
 import org.eclipse.jgit.lib.Ref.Storage;
 import org.eclipse.jgit.lib.RefUpdate.Result;
+import org.eclipse.jgit.storage.file.FileBasedConfig;
 import org.eclipse.jgit.test.resources.SampleDataRepositoryTestCase;
 import org.junit.Test;
 
@@ -82,6 +84,50 @@ public class RefTest extends SampleDataRepositoryTestCase {
 		}
 	}
 
+	@Test
+	public void testRemoteNames() throws Exception {
+		FileBasedConfig config = db.getConfig();
+		config.setBoolean(ConfigConstants.CONFIG_REMOTE_SECTION,
+				"origin", "dummy", true);
+		config.setBoolean(ConfigConstants.CONFIG_REMOTE_SECTION,
+				"ab/c", "dummy", true);
+		config.save();
+		assertEquals("[ab/c, origin]",
+				new TreeSet<String>(db.getRemoteNames()).toString());
+
+		// one-level deep remote branch
+		assertEquals("master",
+				db.shortenRemoteBranchName("refs/remotes/origin/master"));
+		assertEquals("origin", db.getRemoteName("refs/remotes/origin/master"));
+
+		// two-level deep remote branch
+		assertEquals("masta/r",
+				db.shortenRemoteBranchName("refs/remotes/origin/masta/r"));
+		assertEquals("origin", db.getRemoteName("refs/remotes/origin/masta/r"));
+
+		// Remote with slash and one-level deep branch name
+		assertEquals("xmaster",
+				db.shortenRemoteBranchName("refs/remotes/ab/c/xmaster"));
+		assertEquals("ab/c", db.getRemoteName("refs/remotes/ab/c/xmaster"));
+
+		// Remote with slash and two-level deep branch name
+		assertEquals("xmasta/r",
+				db.shortenRemoteBranchName("refs/remotes/ab/c/xmasta/r"));
+		assertEquals("ab/c", db.getRemoteName("refs/remotes/ab/c/xmasta/r"));
+
+		// no such remote
+		assertNull(db.getRemoteName("refs/remotes/nosuchremote/x"));
+		assertNull(db.shortenRemoteBranchName("refs/remotes/nosuchremote/x"));
+
+		// no such remote too, no branch name either
+		assertNull(db.getRemoteName("refs/remotes/abranch"));
+		assertNull(db.shortenRemoteBranchName("refs/remotes/abranch"));
+
+		// // local branch
+		assertNull(db.getRemoteName("refs/heads/abranch"));
+		assertNull(db.shortenRemoteBranchName("refs/heads/abranch"));
+	}
+
 	@Test
 	public void testReadAllIncludingSymrefs() throws Exception {
 		ObjectId masterId = db.resolve("refs/heads/master");

org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java

@@ -1274,6 +1274,40 @@ public abstract class Repository {
 		return refName;
 	}
 
+	/**
+	 * @param refName
+	 * @return the remote branch name part of <code>refName</code>, i.e. without
+	 *         the <code>refs/remotes/&lt;remote&gt;</code> prefix, if
+	 *         <code>refName</code> represents a remote tracking branch;
+	 *         otherwise null.
+	 * @since 3.4
+	 */
+	public String shortenRemoteBranchName(String refName) {
+		for (String remote : getRemoteNames()) {
+			String remotePrefix = Constants.R_REMOTES + remote + "/"; //$NON-NLS-1$
+			if (refName.startsWith(remotePrefix))
+				return refName.substring(remotePrefix.length());
+		}
+		return null;
+	}
+
+	/**
+	 * @param refName
+	 * @return the remote name part of <code>refName</code>, i.e. without the
+	 *         <code>refs/remotes/&lt;remote&gt;</code> prefix, if
+	 *         <code>refName</code> represents a remote tracking branch;
+	 *         otherwise null.
+	 * @since 3.4
+	 */
+	public String getRemoteName(String refName) {
+		for (String remote : getRemoteNames()) {
+			String remotePrefix = Constants.R_REMOTES + remote + "/"; //$NON-NLS-1$
+			if (refName.startsWith(remotePrefix))
+				return remote;
+		}
+		return null;
+	}
+
 	/**
 	 * @param refName
 	 * @return a {@link ReflogReader} for the supplied refname, or null if the
@@ -1613,4 +1647,13 @@ public abstract class Repository {
 			throws IOException {
 		new RebaseTodoFile(this).writeRebaseTodoFile(path, steps, append);
 	}
+
+	/**
+	 * @return the names of all known remotes
+	 * @since 3.4
+	 */
+	public Set<String> getRemoteNames() {
+		return getConfig()
+				.getSubsections(ConfigConstants.CONFIG_REMOTE_SECTION);
+	}
 }