* <many>: (WIP) use ~/mu/xapian as the database with an embedded version tag

- add checks in the code to make sure the database is up to date,
    if not, warn the user.

src/mu-util-xapian.cc

@@ -0,0 +1,61 @@
+/*
+** Copyright (C) 2010 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 3 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software Foundation,
+** Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+**
+*/
+
+#include "config.h"
+#include <xapian.h>
+
+#include <cstring>
+#include "mu-util.h"
+#include "mu-util-xapian.h"
+
+char*
+mu_util_xapian_db_version (const gchar *xpath)
+{
+	try {
+		Xapian::Database db (xpath);
+		const std::string version
+			(db.get_metadata (MU_XAPIAN_VERSION_KEY));
+		
+		return version.empty() ? NULL : g_strdup (version.c_str());
+		
+	} MU_XAPIAN_CATCH_BLOCK;
+
+	return NULL;
+}
+
+
+gboolean
+mu_util_xapian_db_version_up_to_date (const gchar *xpath)
+{
+	gchar *version;
+	gboolean uptodate;
+	
+	version = mu_util_xapian_db_version (xpath);
+	if (!version)
+		return FALSE;
+	
+	uptodate = (std::strcmp (version, MU_XAPIAN_DB_VERSION) == 0); 
+	g_free (version);
+
+	return uptodate;
+}
+
+
+
+