Added refs_for_id to repository

libgitg/gitg-repository.vala

@@ -3,6 +3,8 @@ namespace Gitg
 
 public class Repository : Ggit.Repository
 {
+	private HashTable<Ggit.OId, SList<Gitg.Ref>> d_refs;
+
 	public Repository(File location, File? workdir) throws Error
 	{
 		Object(location: location,
@@ -11,6 +13,62 @@ public class Repository : Ggit.Repository
 		((Initable)this).init(null);
 	}
 
+	private void ensure_refs()
+	{
+		if (d_refs != null)
+		{
+			return;
+		}
+
+		d_refs = new HashTable<Ggit.OId, SList<Gitg.Ref>>(Ggit.OId.hash,
+		                                                  Ggit.OId.equal);
+
+		try
+		{
+			references_foreach(Ggit.RefType.LISTALL, (name) => {
+				Gitg.Ref? r;
+
+				try
+				{
+					r = lookup_reference(name);
+				}
+				catch { return 0; }
+
+				if (r != null)
+				{
+					Ggit.OId? id = r.get_id();
+
+					if (id != null)
+					{
+						unowned SList<Gitg.Ref> refs;
+
+						if (d_refs.lookup_extended(id, null, out refs))
+						{
+							refs.append(r);
+						}
+						else
+						{
+							SList<Gitg.Ref> nrefs = new SList<Gitg.Ref>();
+							nrefs.append(r);
+
+							d_refs.insert(id, (owned)nrefs);
+						}
+					}
+				}
+
+				return 0;
+			});
+		}
+		catch {}
+	}
+
+	public unowned SList<Gitg.Ref> refs_for_id(Ggit.OId id)
+	{
+		ensure_refs();
+
+		return d_refs.lookup(id);
+	}
+
 	// Wrappers for Gitg.Ref
 	public new Ref lookup_reference(string name) throws Error
 	{