i2pd/Queue.h

#ifndef QUEUE_H__
#define QUEUE_H__

#include <queue>
#include <vector>
#include <mutex>
#include <thread>
#include <condition_variable>
#include <functional>
#include <utility>

namespace i2p
{
namespace util
{
	template<typename Element>
	class Queue
	{	
		public:

			void Put (Element e)
			{
				std::unique_lock<std::mutex>  l(m_QueueMutex);
				m_Queue.push (std::move(e));
				m_NonEmpty.notify_one ();
			}

			void Put (const std::vector<Element>& vec)
			{
				if (!vec.empty ())
				{	
					std::unique_lock<std::mutex>  l(m_QueueMutex);
					for (const auto& it: vec)
						m_Queue.push (it);	
					m_NonEmpty.notify_one ();
				}	
			}
			
			Element GetNext ()
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				auto el = GetNonThreadSafe ();
				if (!el)
				{
					m_NonEmpty.wait (l);
					el = GetNonThreadSafe ();
				}	
				return el;
			}

			Element GetNextWithTimeout (int usec)
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				auto el = GetNonThreadSafe ();
				if (!el)
				{
					m_NonEmpty.wait_for (l, std::chrono::milliseconds (usec));
					el = GetNonThreadSafe ();
				}	
				return el;
			}

			void Wait ()
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				m_NonEmpty.wait (l);
			}

			bool Wait (int sec, int usec)
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				return m_NonEmpty.wait_for (l, std::chrono::seconds (sec) + std::chrono::milliseconds (usec)) != std::cv_status::timeout;
			}

			bool IsEmpty () 
			{	
				std::unique_lock<std::mutex> l(m_QueueMutex);
				return m_Queue.empty ();
			}

			int GetSize () 
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				return m_Queue.size ();
			}			

			void WakeUp () { m_NonEmpty.notify_all (); };

			Element Get ()
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				return GetNonThreadSafe ();
			}	

			Element Peek ()
			{
				std::unique_lock<std::mutex> l(m_QueueMutex);
				return GetNonThreadSafe (true);
			}	
			
		private:

			Element GetNonThreadSafe (bool peek = false)
			{
				if (!m_Queue.empty ())
				{
					auto el = m_Queue.front ();
					if (!peek)
						m_Queue.pop ();
					return el;
				}				
				return nullptr;
			}	
			
		private:

			std::queue<Element> m_Queue;
			std::mutex m_QueueMutex;
			std::condition_variable m_NonEmpty;
	};	
}		
}	

#endif