1 files changed, 105 insertions, 0 deletions
diff --git a/src/bin/perfdhcp/tests/rate_control_unittest.cc b/src/bin/perfdhcp/tests/rate_control_unittest.cc
new file mode 100644
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+++ b/src/bin/perfdhcp/tests/rate_control_unittest.cc
@@ -0,0 +1,105 @@
+// Copyright (C) 2013-2019 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 <exceptions/exceptions.h>
+#include "rate_control.h"
+#include <gtest/gtest.h>
+
+
+using namespace isc;
+using namespace isc::perfdhcp;
+
+/// \brief A class which exposes protected methods and members of the
+/// RateControl class (under test).
+class NakedRateControl : public RateControl {
+public:
+
+    /// \brief Default constructor.
+    NakedRateControl()
+        : RateControl() {
+    }
+
+    /// \brief Constructor which sets up the rate.
+    ///
+    /// \param rate A rate at which messages are sent.
+    /// maximal number of messages sent in one chunk.
+    NakedRateControl(const int rate)
+        : RateControl(rate) {
+    }
+
+    using RateControl::currentTime;
+    using RateControl::start_time_;
+};
+
+// Test default constructor.
+TEST(RateControl, constructorDefault) {
+    NakedRateControl rc;
+    EXPECT_EQ(0, rc.getRate());
+}
+
+// Test the constructor which sets the rate.
+TEST(RateControl, constructor) {
+    // Call the constructor and verify that it sets the appropriate
+    // values.
+    NakedRateControl rc1(3);
+    EXPECT_EQ(3, rc1.getRate());
+
+    // Call the constructor again and make sure that different values
+    // will be set correctly.
+    NakedRateControl rc2(5);
+    EXPECT_EQ(5, rc2.getRate());
+}
+
+// Check the rate accessor.
+TEST(RateControl, getRate) {
+    RateControl rc;
+    ASSERT_EQ(0, rc.getRate());
+    rc.setRate(5);
+    ASSERT_EQ(5, rc.getRate());
+    rc.setRate(10);
+    EXPECT_EQ(10, rc.getRate());
+}
+
+// Check that the function returns the number of messages to be sent "now"
+// correctly.
+// @todo Possibly extend this test to cover more complex scenarios. Note that
+// it is quite hard to fully test this function as its behaviour strongly
+// depends on time.
+TEST(RateControl, getOutboundMessageCount) {
+    // Test that the number of outbound messages is correctly defined by the
+    // rate.
+    NakedRateControl rc(2);
+
+    // The first call to getOutboundMessageCount always returns 0 as there is
+    // no good estimate at the beginning how many packets to send.
+    uint64_t count = 0;
+    ASSERT_NO_THROW(count = rc.getOutboundMessageCount());
+    EXPECT_EQ(count, 1);
+
+    // After a given amount of time number of packets to send should
+    // allow to catch up with requested rate, ie for rate 2pks/s after 1500ms
+    // it should send 2 pkts/s * 1.5s = about 2 pkts.
+    // To simulate 1500ms lets get back start time by 1500ms.
+    rc.start_time_ -= boost::posix_time::milliseconds(1500);
+    ASSERT_NO_THROW(count = rc.getOutboundMessageCount());
+    EXPECT_EQ(count, 2);
+
+    // If elapsed time is big then a big number of packets would need to be sent.
+    // But the pkts number is capped to 3. Check it.
+    rc.start_time_ -= boost::posix_time::milliseconds(10000);
+    ASSERT_NO_THROW(count = rc.getOutboundMessageCount());
+    EXPECT_EQ(count, 3);
+}
+
+// Test the rate modifier for valid and invalid rate values.
+TEST(RateControl, setRate) {
+    NakedRateControl rc;
+    EXPECT_NO_THROW(rc.setRate(1));
+    EXPECT_NO_THROW(rc.setRate(0));
+    EXPECT_THROW(rc.setRate(-1), isc::BadValue);
+}