Remove NTPServers duplicate values and null values

When saving the set NTPServers values from webUI, NTPServer may contain
duplicate values and null values and update them to D-Bus.

Now, need to parse and verify the value of the ntpServers attribute,and
remove duplicate values and null values.

Tested:save NTP and check it via D-Bus
without this patch:
NTPServers  property  as  3 "" "10.164.29.2" "10.164.29.2"

with this patch:
NTPServers  property  as  2 "" "10.164.29.2"

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I52291e4608efd635b179f3934c3d3e805afd2209

1 files changed, 39 insertions, 0 deletions

diff --git a/redfish-core/include/utils/stl_utils.hpp b/redfish-core/include/utils/stl_utils.hpp
new file mode 100644
index 0000000000..04d02cbada
--- /dev/null
+++ b/redfish-core/include/utils/stl_utils.hpp
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <algorithm>
+#include <string>
+
+namespace redfish
+{
+
+namespace stl_utils
+{
+
+template <typename ForwardIterator>
+ForwardIterator firstDuplicate(ForwardIterator first, ForwardIterator last)
+{
+    auto newLast = first;
+
+    for (auto current = first; current != last; ++current)
+    {
+        if (std::find(first, newLast, *current) == newLast)
+        {
+            if (newLast != current)
+            {
+                *newLast = *current;
+            }
+            ++newLast;
+        }
+    }
+
+    return newLast;
+}
+
+template <typename T>
+void removeDuplicate(T& t)
+{
+    t.erase(firstDuplicate(t.begin(), t.end()), t.end());
+}
+
+} // namespace stl_utils
+} // namespace redfish