1 files changed, 90 insertions, 0 deletions
diff --git a/src/hooks/dhcp/high_availability/lease_update_backlog.cc b/src/hooks/dhcp/high_availability/lease_update_backlog.cc
new file mode 100644
index 0000000..3953f1c
--- /dev/null
+++ b/src/hooks/dhcp/high_availability/lease_update_backlog.cc
@@ -0,0 +1,90 @@
+// Copyright (C) 2020-2021 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/.
+
+#include <config.h>
+
+#include <lease_update_backlog.h>
+#include <util/multi_threading_mgr.h>
+
+using namespace isc::dhcp;
+
+namespace isc {
+namespace ha {
+
+LeaseUpdateBacklog::LeaseUpdateBacklog(const size_t limit)
+    : limit_(limit), overflown_(false), outstanding_updates_() {
+}
+
+bool
+LeaseUpdateBacklog::push(const LeaseUpdateBacklog::OpType op_type, const LeasePtr& lease) {
+    if (util::MultiThreadingMgr::instance().getMode()) {
+        std::lock_guard<std::mutex> lock(mutex_);
+        return (pushInternal(op_type, lease));
+    }
+    return (pushInternal(op_type, lease));
+}
+
+LeasePtr
+LeaseUpdateBacklog::pop(LeaseUpdateBacklog::OpType& op_type) {
+    if (util::MultiThreadingMgr::instance().getMode()) {
+        std::lock_guard<std::mutex> lock(mutex_);
+        return (popInternal(op_type));
+    }
+    return (popInternal(op_type));
+}
+
+bool
+LeaseUpdateBacklog::wasOverflown() {
+    if (util::MultiThreadingMgr::instance().getMode()) {
+        std::lock_guard<std::mutex> lock(mutex_);
+        return (overflown_);
+    }
+    return (overflown_);
+}
+
+void
+LeaseUpdateBacklog::clear() {
+    if (util::MultiThreadingMgr::instance().getMode()) {
+        std::lock_guard<std::mutex> lock(mutex_);
+        outstanding_updates_.clear();
+        overflown_ = false;
+    }
+    outstanding_updates_.clear();
+    overflown_ = false;
+}
+
+size_t
+LeaseUpdateBacklog::size() {
+    if (util::MultiThreadingMgr::instance().getMode()) {
+        std::lock_guard<std::mutex> lock(mutex_);
+        return (outstanding_updates_.size());
+    }
+    return (outstanding_updates_.size());
+}
+
+bool
+LeaseUpdateBacklog::pushInternal(const LeaseUpdateBacklog::OpType op_type, const LeasePtr& lease) {
+    if (outstanding_updates_.size() >= limit_) {
+        overflown_ = true;
+        return (false);
+    }
+    outstanding_updates_.push_back(std::make_pair(op_type, lease));
+    return (true);
+}
+
+LeasePtr
+LeaseUpdateBacklog::popInternal(LeaseUpdateBacklog::OpType& op_type) {
+    if (outstanding_updates_.empty()) {
+        return (LeasePtr());
+    }
+    auto item = outstanding_updates_.front();
+    outstanding_updates_.pop_front();
+    op_type = item.first;
+    return (item.second);
+}
+
+} // end of namespace isc::ha
+} // end of namespace isc