1 files changed, 60 insertions, 0 deletions
diff --git a/src/lib/dhcpsrv/callout_handle_store.h b/src/lib/dhcpsrv/callout_handle_store.h
new file mode 100644
index 0000000..402c9df
--- /dev/null
+++ b/src/lib/dhcpsrv/callout_handle_store.h
@@ -0,0 +1,60 @@
+// Copyright (C) 2013-2018,2021 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/.
+
+#ifndef CALLOUT_HANDLE_STORE_H
+#define CALLOUT_HANDLE_STORE_H
+
+#include <hooks/hooks_manager.h>
+#include <hooks/callout_handle.h>
+#include <map>
+#include <set>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief CalloutHandle Store
+///
+/// When using the Hooks Framework, there is a need to associate an
+/// isc::hooks::CalloutHandle object with each request passing through the
+/// server.  For the DHCP servers, the association was provided by this function.
+///
+/// After introduction of "packets parking" feature this function was extended
+/// to keep association of packets with the callout handles in a map.
+/// However, it was later found that "garbage collection" of the unused
+/// handles is very hard. Trying to garbage collect handles at each invocation
+/// was highly inefficient and caused server's performance degradation.
+///
+/// The new approach is using on @c isc::hooks::CalloutHandleAssociate to
+/// associate objects with callout handles. This has a major benefit that
+/// callout handle instances are removed together with the packets associated
+/// with them.
+///
+/// This function uses this new approach and is kept for the compatibility with
+/// existing code.
+///
+/// @tparam T Pkt4Ptr or Pkt6Ptr object.
+/// @param pktptr Pointer to the packet being processed.  This is typically a
+///        Pkt4Ptr or Pkt6Ptr object.
+///
+/// @return Shared pointer to a CalloutHandle. This is the previously-stored
+///         CalloutHandle if pktptr points to a packet that has been seen
+///         before or a new CalloutHandle if it points to a new one. An empty
+///         pointer is returned if pktptr is itself an empty pointer.
+template <typename T>
+isc::hooks::CalloutHandlePtr getCalloutHandle(const T& pktptr) {
+
+    if (pktptr) {
+        return (pktptr->getCalloutHandle());
+
+    }
+
+    return (isc::hooks::CalloutHandlePtr());
+}
+
+} // namespace dhcp
+} // namespace isc
+
+#endif // CALLOUT_HANDLE_STORE_H