util: Add EventEmitter
Change-Id: I08e8beea7a05abe30cc818ec2d44acffecf07343
diff --git a/src/util/event-emitter.hpp b/src/util/event-emitter.hpp
new file mode 100644
index 0000000..adbd231
--- /dev/null
+++ b/src/util/event-emitter.hpp
@@ -0,0 +1,381 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ *
+ * This code is actually copied from NFD project (NDN Forwarding Daemon).
+ * We acknowledge the permission of the authors of NFD.
+ */
+/**
+ * Copyright (c) 2014 Regents of the University of California,
+ * Arizona Board of Regents,
+ * Colorado State University,
+ * University Pierre & Marie Curie, Sorbonne University,
+ * Washington University in St. Louis,
+ * Beijing Institute of Technology
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#ifndef NDN_UTIL_EVENT_EMITTER_HPP
+#define NDN_UTIL_EVENT_EMITTER_HPP
+
+#include "common.hpp"
+#include <vector>
+
+namespace ndn {
+namespace util {
+
+struct empty
+{
+};
+
+/** \class EventEmitter
+ * \brief provides a lightweight event system
+ *
+ * To declare an event:
+ * EventEmitter<TArgs> onEventName;
+ * To subscribe to an event:
+ * eventSource->onEventName += eventHandler;
+ * Multiple functions can subscribe to the same event.
+ * To trigger an event:
+ * onEventName(args);
+ * To clear event subscriptions:
+ * onEventName.clear();
+ */
+
+// four arguments
+template<typename T1 = empty, typename T2 = empty,
+ typename T3 = empty, typename T4 = empty>
+class EventEmitter : noncopyable
+{
+public:
+ /// represents a handler that can subscribe to the event
+ typedef function<void(const T1&, const T2&,
+ const T3&, const T4&)> Handler;
+
+ /// adds an subscription
+ void
+ operator+=(Handler handler);
+
+ /// returns true if there is no subscription,
+ /// otherwise returns false
+ bool
+ isEmpty() const;
+
+ /// clears all subscriptions
+ void
+ clear();
+
+ /// triggers the event
+ void
+ operator()(const T1& a1, const T2& a2, const T3& a3, const T4& a4);
+
+private:
+ /// stores all subscribed handlers
+ std::vector<Handler> m_handlers;
+};
+
+// zero argument
+template<>
+class EventEmitter<empty, empty, empty, empty> : noncopyable
+{
+public:
+ typedef function<void()> Handler;
+
+ void
+ operator+=(Handler handler);
+
+ bool
+ isEmpty() const;
+
+ void
+ clear();
+
+ void
+ operator()();
+
+private:
+ std::vector<Handler> m_handlers;
+};
+
+
+// one argument
+template<typename T1>
+class EventEmitter<T1, empty, empty, empty> : noncopyable
+{
+public:
+ typedef function<void(const T1&)> Handler;
+
+ void
+ operator+=(Handler handler);
+
+ bool
+ isEmpty() const;
+
+ void
+ clear();
+
+ void
+ operator()(const T1& a1);
+
+private:
+ std::vector<Handler> m_handlers;
+};
+
+
+// two arguments
+template<typename T1, typename T2>
+class EventEmitter<T1, T2, empty, empty> : noncopyable
+{
+public:
+ typedef function<void(const T1&, const T2&)> Handler;
+
+ void
+ operator+=(Handler handler);
+
+ bool
+ isEmpty() const;
+
+ void
+ clear();
+
+ void
+ operator()(const T1& a1, const T2& a2);
+
+private:
+ std::vector<Handler> m_handlers;
+};
+
+
+// three arguments
+template<typename T1, typename T2, typename T3>
+class EventEmitter<T1, T2, T3, empty> : noncopyable
+{
+public:
+ typedef function<void(const T1&, const T2&, const T3&)> Handler;
+
+ void
+ operator+=(Handler handler);
+
+ bool
+ isEmpty() const;
+
+ void
+ clear();
+
+ void
+ operator()(const T1& a1, const T2& a2, const T3& a3);
+
+private:
+ std::vector<Handler> m_handlers;
+};
+
+
+// zero argument
+
+inline void
+EventEmitter<empty, empty, empty, empty>::operator+=(Handler handler)
+{
+ m_handlers.push_back(handler);
+}
+
+inline bool
+EventEmitter<empty, empty, empty, empty>::isEmpty() const
+{
+ return m_handlers.empty();
+}
+
+inline void
+EventEmitter<empty, empty, empty, empty>::clear()
+{
+ return m_handlers.clear();
+}
+
+inline void
+EventEmitter<empty, empty, empty, empty>::operator()()
+{
+ std::vector<Handler>::iterator it;
+ for (it = m_handlers.begin(); it != m_handlers.end(); ++it) {
+ (*it)();
+ if (m_handlers.empty()) // .clear has been called
+ return;
+ }
+}
+
+// one argument
+
+template<typename T1>
+inline void
+EventEmitter<T1, empty, empty, empty>::operator+=(Handler handler)
+{
+ m_handlers.push_back(handler);
+}
+
+template<typename T1>
+inline bool
+EventEmitter<T1, empty, empty, empty>::isEmpty() const
+{
+ return m_handlers.empty();
+}
+
+template<typename T1>
+inline void
+EventEmitter<T1, empty, empty, empty>::clear()
+{
+ return m_handlers.clear();
+}
+
+template<typename T1>
+inline void
+EventEmitter<T1, empty, empty, empty>::operator()(const T1& a1)
+{
+ typename std::vector<Handler>::iterator it;
+ for (it = m_handlers.begin(); it != m_handlers.end(); ++it) {
+ (*it)(a1);
+ if (m_handlers.empty()) // .clear has been called
+ return;
+ }
+}
+
+// two arguments
+
+template<typename T1, typename T2>
+inline void
+EventEmitter<T1, T2, empty, empty>::operator+=(Handler handler)
+{
+ m_handlers.push_back(handler);
+}
+
+template<typename T1, typename T2>
+inline bool
+EventEmitter<T1, T2, empty, empty>::isEmpty() const
+{
+ return m_handlers.empty();
+}
+
+template<typename T1, typename T2>
+inline void
+EventEmitter<T1, T2, empty, empty>::clear()
+{
+ return m_handlers.clear();
+}
+
+template<typename T1, typename T2>
+inline void
+EventEmitter<T1, T2, empty, empty>::operator()
+ (const T1& a1, const T2& a2)
+{
+ typename std::vector<Handler>::iterator it;
+ for (it = m_handlers.begin(); it != m_handlers.end(); ++it) {
+ (*it)(a1, a2);
+ if (m_handlers.empty()) // .clear has been called
+ return;
+ }
+}
+
+// three arguments
+
+template<typename T1, typename T2, typename T3>
+inline void
+EventEmitter<T1, T2, T3, empty>::operator+=(Handler handler)
+{
+ m_handlers.push_back(handler);
+}
+
+template<typename T1, typename T2, typename T3>
+inline bool
+EventEmitter<T1, T2, T3, empty>::isEmpty() const
+{
+ return m_handlers.empty();
+}
+
+template<typename T1, typename T2, typename T3>
+inline void
+EventEmitter<T1, T2, T3, empty>::clear()
+{
+ return m_handlers.clear();
+}
+
+template<typename T1, typename T2, typename T3>
+inline void
+EventEmitter<T1, T2, T3, empty>::operator()
+ (const T1& a1, const T2& a2, const T3& a3)
+{
+ typename std::vector<Handler>::iterator it;
+ for (it = m_handlers.begin(); it != m_handlers.end(); ++it) {
+ (*it)(a1, a2, a3);
+ if (m_handlers.empty()) // .clear has been called
+ return;
+ }
+}
+
+// four arguments
+
+template<typename T1, typename T2, typename T3, typename T4>
+inline void
+EventEmitter<T1, T2, T3, T4>::operator+=(Handler handler)
+{
+ m_handlers.push_back(handler);
+}
+
+template<typename T1, typename T2, typename T3, typename T4>
+inline bool
+EventEmitter<T1, T2, T3, T4>::isEmpty() const
+{
+ return m_handlers.empty();
+}
+
+template<typename T1, typename T2, typename T3, typename T4>
+inline void
+EventEmitter<T1, T2, T3, T4>::clear()
+{
+ return m_handlers.clear();
+}
+
+template<typename T1, typename T2, typename T3, typename T4>
+inline void
+EventEmitter<T1, T2, T3, T4>::operator()
+ (const T1& a1, const T2& a2, const T3& a3, const T4& a4)
+{
+ typename std::vector<Handler>::iterator it;
+ for (it = m_handlers.begin(); it != m_handlers.end(); ++it) {
+ (*it)(a1, a2, a3, a4);
+ if (m_handlers.empty()) // .clear has been called
+ return;
+ }
+}
+
+
+} // namespace util
+} // namespace ndn
+
+#endif // NDN_UTIL_EVENT_EMITTER_HPP
diff --git a/tests/unit-tests/util/test-event-emitter.cpp b/tests/unit-tests/util/test-event-emitter.cpp
new file mode 100644
index 0000000..8dd5314
--- /dev/null
+++ b/tests/unit-tests/util/test-event-emitter.cpp
@@ -0,0 +1,275 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2014 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ *
+ * This code is actually copied from NFD project (NDN Forwarding Daemon).
+ * We acknowledge the permission of the authors of NFD.
+ */
+/**
+ * Copyright (c) 2014 Regents of the University of California,
+ * Arizona Board of Regents,
+ * Colorado State University,
+ * University Pierre & Marie Curie, Sorbonne University,
+ * Washington University in St. Louis,
+ * Beijing Institute of Technology
+ *
+ * This file is part of NFD (Named Data Networking Forwarding Daemon).
+ * See AUTHORS.md for complete list of NFD authors and contributors.
+ *
+ * NFD is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NFD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NFD, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+#include "util/event-emitter.hpp"
+
+#include "boost-test.hpp"
+
+namespace ndn {
+namespace tests {
+
+using ndn::util::EventEmitter;
+
+BOOST_AUTO_TEST_SUITE(UtilEventEmitter)
+
+class EventEmitterTester : noncopyable
+{
+public:
+ EventEmitterTester();
+
+ int m_hit;
+ int m_a1;
+ int m_a2;
+ int m_a3;
+ int m_a4;
+
+ void
+ clear();
+
+ void
+ f0();
+
+ void
+ f1(int a1);
+
+ void
+ f2(int a1, int a2);
+
+ void
+ f3(int a1, int a2, int a3);
+
+ void
+ f4(int a1, int a2, int a3, int a4);
+};
+
+EventEmitterTester::EventEmitterTester()
+{
+ this->clear();
+}
+
+void
+EventEmitterTester::clear()
+{
+ m_hit = 0;
+ m_a1 = 0;
+ m_a2 = 0;
+ m_a3 = 0;
+ m_a4 = 0;
+}
+
+void
+EventEmitterTester::f0()
+{
+ ++m_hit;
+}
+
+void
+EventEmitterTester::f1(int a1)
+{
+ ++m_hit;
+ m_a1 = a1;
+}
+
+void
+EventEmitterTester::f2(int a1, int a2)
+{
+ ++m_hit;
+ m_a1 = a1;
+ m_a2 = a2;
+}
+
+void
+EventEmitterTester::f3(int a1, int a2, int a3)
+{
+ ++m_hit;
+ m_a1 = a1;
+ m_a2 = a2;
+ m_a3 = a3;
+}
+
+void
+EventEmitterTester::f4(int a1, int a2, int a3, int a4)
+{
+ ++m_hit;
+ m_a1 = a1;
+ m_a2 = a2;
+ m_a3 = a3;
+ m_a4 = a4;
+}
+
+static int g_EventEmitterTest_RefObject_copyCount;
+
+class EventEmitterTest_RefObject
+{
+public:
+ EventEmitterTest_RefObject() {}
+
+ EventEmitterTest_RefObject(const EventEmitterTest_RefObject& other);
+};
+
+EventEmitterTest_RefObject::EventEmitterTest_RefObject(const EventEmitterTest_RefObject& other)
+{
+ ++g_EventEmitterTest_RefObject_copyCount;
+}
+
+void
+EventEmitterTest_RefObject_byVal(EventEmitterTest_RefObject a1) {}
+
+void
+EventEmitterTest_RefObject_byRef(const EventEmitterTest_RefObject& a1) {}
+
+
+BOOST_AUTO_TEST_CASE(ZeroListener)
+{
+ EventEmitter<> ee;
+ BOOST_CHECK_NO_THROW(ee());
+}
+
+BOOST_AUTO_TEST_CASE(TwoListeners)
+{
+ EventEmitterTester eet1;
+ EventEmitterTester eet2;
+ EventEmitter<> ee;
+ ee += bind(&EventEmitterTester::f0, &eet1);
+ ee += bind(&EventEmitterTester::f0, &eet2);
+ ee();
+
+ BOOST_CHECK_EQUAL(eet1.m_hit, 1);
+ BOOST_CHECK_EQUAL(eet2.m_hit, 1);
+}
+
+BOOST_AUTO_TEST_CASE(ZeroArgument)
+{
+ EventEmitterTester eet;
+ EventEmitter<> ee;
+ ee += bind(&EventEmitterTester::f0, &eet);
+ ee();
+
+ BOOST_CHECK_EQUAL(eet.m_hit, 1);
+}
+
+BOOST_AUTO_TEST_CASE(OneArgument)
+{
+ EventEmitterTester eet;
+ EventEmitter<int> ee;
+ ee += bind(&EventEmitterTester::f1, &eet, _1);
+ ee(11);
+
+ BOOST_CHECK_EQUAL(eet.m_hit, 1);
+ BOOST_CHECK_EQUAL(eet.m_a1, 11);
+}
+
+BOOST_AUTO_TEST_CASE(TwoArguments)
+{
+ EventEmitterTester eet;
+ EventEmitter<int,int> ee;
+ ee += bind(&EventEmitterTester::f2, &eet, _1, _2);
+ ee(21, 22);
+
+ BOOST_CHECK_EQUAL(eet.m_hit, 1);
+ BOOST_CHECK_EQUAL(eet.m_a1, 21);
+ BOOST_CHECK_EQUAL(eet.m_a2, 22);
+}
+
+BOOST_AUTO_TEST_CASE(ThreeArguments)
+{
+ EventEmitterTester eet;
+ EventEmitter<int,int,int> ee;
+ ee += bind(&EventEmitterTester::f3, &eet, _1, _2, _3);
+ ee(31, 32, 33);
+
+ BOOST_CHECK_EQUAL(eet.m_hit, 1);
+ BOOST_CHECK_EQUAL(eet.m_a1, 31);
+ BOOST_CHECK_EQUAL(eet.m_a2, 32);
+ BOOST_CHECK_EQUAL(eet.m_a3, 33);
+}
+
+BOOST_AUTO_TEST_CASE(FourArguments)
+{
+ EventEmitterTester eet;
+ EventEmitter<int,int,int,int> ee;
+ ee += bind(&EventEmitterTester::f4, &eet, _1, _2, _3, _4);
+ ee(41, 42, 43, 44);
+
+ BOOST_CHECK_EQUAL(eet.m_hit, 1);
+ BOOST_CHECK_EQUAL(eet.m_a1, 41);
+ BOOST_CHECK_EQUAL(eet.m_a2, 42);
+ BOOST_CHECK_EQUAL(eet.m_a3, 43);
+ BOOST_CHECK_EQUAL(eet.m_a4, 44);
+}
+
+// EventEmitter passes arguments by reference,
+// but it also allows a handler that accept arguments by value
+BOOST_AUTO_TEST_CASE(HandlerByVal)
+{
+ EventEmitterTest_RefObject refObject;
+ g_EventEmitterTest_RefObject_copyCount = 0;
+
+ EventEmitter<EventEmitterTest_RefObject> ee;
+ ee += &EventEmitterTest_RefObject_byVal;
+ ee(refObject);
+
+ BOOST_CHECK_EQUAL(g_EventEmitterTest_RefObject_copyCount, 1);
+}
+
+// EventEmitter passes arguments by reference, and no copying
+// is necessary when handler accepts arguments by reference
+BOOST_AUTO_TEST_CASE(HandlerByRef)
+{
+ EventEmitterTest_RefObject refObject;
+ g_EventEmitterTest_RefObject_copyCount = 0;
+
+ EventEmitter<EventEmitterTest_RefObject> ee;
+ ee += &EventEmitterTest_RefObject_byRef;
+ ee(refObject);
+
+ BOOST_CHECK_EQUAL(g_EventEmitterTest_RefObject_copyCount, 0);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+} // namespace tests
+} // namespace ndn