1 files changed, 137 insertions, 0 deletions
diff --git a/src/lib/testutils/user_context_utils.cc b/src/lib/testutils/user_context_utils.cc
new file mode 100644
index 0000000..bad26bc
--- /dev/null
+++ b/src/lib/testutils/user_context_utils.cc
@@ -0,0 +1,137 @@
+// Copyright (C) 2017-2020 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <testutils/user_context_utils.h>
+
+using namespace isc::data;
+
+namespace {
+
+/// @brief Encapsulate either a modified copy or a unmodified value
+/// @tparam EP ElementPtr or ConstElementPtr (compiler can't infer which one)
+template<typename EP>
+class Value {
+public:
+    /// @brief Factory for modified copy
+    static Value mkCopy(EP value) { return (Value(value, false)); }
+
+    /// @brief Factory for unmodified original
+    static Value mkShare(EP value) { return (Value(value, true)); }
+
+    /// @brief Get the value
+    /// @return the value
+    EP get() const { return (value_); }
+
+    /// @brief Get the shared status
+    /// @return true if original, false if copy
+    bool isShared() const { return (shared_); }
+
+private:
+    /// @brief Constructor
+    /// @param value the modified copy or unmodified value
+    /// @param shared true if original, false if copy
+    Value(EP value, bool shared) : value_(value), shared_(shared) { }
+
+    /// @brief the value
+    EP value_;
+
+    /// @brief the shared status
+    bool shared_;
+};
+
+/// @brief Recursive helper
+///
+/// @tparam EP ElementPtr or ConstElementPtr (compiler will infer which one)
+/// @param element the element to traverse
+/// @return a modified copy where comment entries were moved to user-context
+/// or the unmodified original argument encapsulated into a Value
+template<typename EP>
+Value<EP> moveComments1(EP element) {
+    bool modified = false;
+
+    // On lists recurse on items
+    if (element->getType() == Element::list) {
+        ElementPtr result = ElementPtr(new ListElement());
+        typedef std::vector<ElementPtr> ListType;
+        const ListType& list = element->listValue();
+        for (ListType::const_iterator it = list.cbegin();
+             it != list.cend(); ++it) {
+            Value<ElementPtr> item = moveComments1(*it);
+            result->add(item.get());
+            if (!item.isShared()) {
+                modified = true;
+            }
+        }
+        if (!modified) {
+            return (Value<EP>::mkShare(element));
+        } else {
+            return (Value<EP>::mkCopy(result));
+        }
+    } else if (element->getType() != Element::map) {
+        return (Value<EP>::mkShare(element));
+    }
+
+    // Process maps: recurse on items
+    ElementPtr result = ElementPtr(new MapElement());
+    bool has_comment = false;
+    typedef std::map<std::string, ConstElementPtr> map_type;
+    const map_type& map = element->mapValue();
+    for (map_type::const_iterator it = map.cbegin(); it != map.cend(); ++it) {
+        if (it->first == "comment") {
+            // Note there is a comment entry to move
+            has_comment = true;
+        } else if (it->first == "user-context") {
+            // Do not traverse user-context entries
+            result->set("user-context", it->second);
+        } else {
+            // Not comment or user-context
+            Value<ConstElementPtr> item = moveComments1(it->second);
+            result->set(it->first, item.get());
+            if (!item.isShared()) {
+                modified = true;
+            }
+        }
+    }
+    // Check if the value should be not modified
+    if (!has_comment && !modified) {
+        return (Value<EP>::mkShare(element));
+    }
+
+    if (has_comment) {
+        // Move the comment entry
+        ConstElementPtr comment = element->get("comment");
+        ElementPtr moved = Element::createMap();
+        moved->set("comment", comment);
+        ConstElementPtr previous = element->get("user-context");
+        // If there is already a user context merge it
+        if (previous) {
+                merge(moved, previous);
+        }
+        result->set("user-context", moved);
+    }
+
+    return (Value<EP>::mkCopy(result));
+}
+
+} // anonymous namespace
+
+namespace isc {
+namespace test {
+
+ElementPtr moveComments(ElementPtr element) {
+    Value<ElementPtr> result = moveComments1(element);
+    return (result.get());
+}
+
+ConstElementPtr moveComments(ConstElementPtr element) {
+    Value<ConstElementPtr> result = moveComments1(element);
+    return (result.get());
+}
+
+} // end of isc::test namespace
+} // end of isc namespace