1 files changed, 56 insertions, 0 deletions
diff --git a/indra/llcommon/llcommonutils.cpp b/indra/llcommon/llcommonutils.cpp
new file mode 100644
index 0000000000..d82554c202
--- /dev/null
+++ b/indra/llcommon/llcommonutils.cpp
@@ -0,0 +1,56 @@
+/**
+ * @file llcommonutils.h
+ * @brief Commin utils
+ *
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library 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
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+#include "llcommonutils.h"
+
+void LLCommonUtils::computeDifference(
+	const uuid_vec_t& vnew,
+	const uuid_vec_t& vcur,
+	uuid_vec_t& vadded,
+	uuid_vec_t& vremoved)
+{
+	uuid_vec_t vnew_copy(vnew);
+	uuid_vec_t vcur_copy(vcur);
+
+	std::sort(vnew_copy.begin(), vnew_copy.end());
+	std::sort(vcur_copy.begin(), vcur_copy.end());
+
+	size_t maxsize = llmax(vnew_copy.size(), vcur_copy.size());
+	vadded.resize(maxsize);
+	vremoved.resize(maxsize);
+
+	uuid_vec_t::iterator it;
+	// what was removed
+	it = set_difference(vcur_copy.begin(), vcur_copy.end(), vnew_copy.begin(), vnew_copy.end(), vremoved.begin());
+	vremoved.erase(it, vremoved.end());
+
+	// what was added
+	it = set_difference(vnew_copy.begin(), vnew_copy.end(), vcur_copy.begin(), vcur_copy.end(), vadded.begin());
+	vadded.erase(it, vadded.end());
+}
+
+// EOF