replaced stringstream by a list of buffers

Streaming.cpp

@@ -11,6 +11,50 @@ namespace i2p
 {
 namespace stream
 {
+	void SendBufferQueue::Add (const uint8_t * buf, size_t len, SendHandler handler)
+	{	
+		m_Buffers.push_back (std::make_shared<SendBuffer>(buf, len, handler));
+		m_Size += len;
+	}
+	
+	size_t SendBufferQueue::Get (uint8_t * buf, size_t len)
+	{
+		size_t offset = 0;
+		while (!m_Buffers.empty () && offset < len)
+		{
+			auto nextBuffer = m_Buffers.front ();
+			auto rem = nextBuffer->GetRemainingSize ();
+			if (offset + rem <= len)
+			{
+				// whole buffer
+				memcpy (buf + offset, nextBuffer->GetRemaningBuffer (), rem);
+				offset += rem;
+				m_Buffers.pop_front (); // delete it
+			}	
+			else
+			{
+				// partially
+				rem =  len - offset;
+				memcpy (buf + offset, nextBuffer->GetRemaningBuffer (), len - offset);
+				nextBuffer->offset += (len - offset);
+				offset = len; // break
+			}	
+		}	
+		m_Size -= offset;
+		return offset;
+	}	
+
+	void SendBufferQueue::CleanUp () 
+	{ 
+		if (!m_Buffers.empty ())
+		{	
+			for (auto it: m_Buffers)
+				it->Cancel ();
+			m_Buffers.clear (); 
+			m_Size = 0;
+		}	
+	}
+	
 	Stream::Stream (boost::asio::io_service& service, StreamingDestination& local,
 		std::shared_ptr<const i2p::data::LeaseSet> remote, int port): m_Service (service),
 		m_SendStreamID (0), m_SequenceNumber (0), m_LastReceivedSequenceNumber (-1),
@@ -45,19 +89,16 @@ namespace stream
 		m_AckSendTimer.cancel ();
 		m_ReceiveTimer.cancel ();
 		m_ResendTimer.cancel ();
-		if (m_SendHandler)
-		{
-			auto handler = m_SendHandler;
-			m_SendHandler = nullptr;
-			handler (boost::asio::error::make_error_code (boost::asio::error::operation_aborted));
-		}
 		//CleanUp (); /* Need to recheck - broke working on windows */
 		m_LocalDestination.DeleteStream (shared_from_this ());
 	}
 
 	void Stream::CleanUp ()
 	{
-		m_SendBuffer.str ("");
+		{
+			std::unique_lock<std::mutex> l(m_SendBufferMutex);
+			m_SendBuffer.CleanUp ();
+		}	
 		while (!m_ReceiveQueue.empty ())
 		{
 			auto packet = m_ReceiveQueue.front ();
@@ -321,23 +362,21 @@ namespace stream
 
 	size_t Stream::Send (const uint8_t * buf, size_t len)
 	{
-		if (len > 0 && buf)
-		{
-			std::unique_lock<std::mutex> l(m_SendBufferMutex);
-			m_SendBuffer.clear ();
-			m_SendBuffer.write ((const char *)buf, len);
-		}
-		m_Service.post (std::bind (&Stream::SendBuffer, shared_from_this ()));
+		// TODO: check max buffer size
+		AsyncSend (buf, len, nullptr);
 		return len;
 	}
 
 	void Stream::AsyncSend (const uint8_t * buf, size_t len, SendHandler handler)
 	{
-		if (m_SendHandler)
-			handler (boost::asio::error::make_error_code (boost::asio::error::in_progress));
-		else
-			m_SendHandler = handler;
-		Send (buf, len);
+		if (len > 0 && buf)
+		{
+			std::unique_lock<std::mutex> l(m_SendBufferMutex);
+			m_SendBuffer.Add (buf, len, handler);
+		}
+		else if (handler)
+			 handler(boost::system::error_code ());
+		m_Service.post (std::bind (&Stream::SendBuffer, shared_from_this ()));
 	}
 
 	void Stream::SendBuffer ()
@@ -349,7 +388,7 @@ namespace stream
 		std::vector<Packet *> packets;
 		{
 			std::unique_lock<std::mutex> l(m_SendBufferMutex);
-			while ((m_Status == eStreamStatusNew) || (IsEstablished () && !m_SendBuffer.eof () && numMsgs > 0))
+			while ((m_Status == eStreamStatusNew) || (IsEstablished () && !m_SendBuffer.IsEmpty () && numMsgs > 0))
 			{
 				Packet * p = m_LocalDestination.NewPacket ();
 				uint8_t * packet = p->GetBuffer ();
@@ -390,8 +429,7 @@ namespace stream
 					uint8_t * signature = packet + size; // set it later
 					memset (signature, 0, signatureLen); // zeroes for now
 					size += signatureLen; // signature
-					m_SendBuffer.read ((char *)(packet + size), STREAMING_MTU - size);
-					size += m_SendBuffer.gcount (); // payload
+					size += m_SendBuffer.Get (packet + size, STREAMING_MTU - size); // payload
 					m_LocalDestination.GetOwner ()->Sign (packet, size, signature);
 				}
 				else
@@ -401,22 +439,12 @@ namespace stream
 					size += 2; // flags
 					htobuf16 (packet + size, 0); // no options
 					size += 2; // options size
-					m_SendBuffer.read((char *)(packet + size), STREAMING_MTU - size);
-					size += m_SendBuffer.gcount (); // payload
+					size += m_SendBuffer.Get(packet + size, STREAMING_MTU - size); // payload
 				}
 				p->len = size;
 				packets.push_back (p);
 				numMsgs--;
 			}
-			if (m_SendBuffer.eof ())
-			{
-				m_SendBuffer.str(""); // clean up buffer
-				if (m_SendHandler)
-				{
-					m_SendHandler (boost::system::error_code ());
-					m_SendHandler = nullptr;
-				}
-			}
 		}
 		if (packets.size () > 0)
 		{
@@ -433,7 +461,7 @@ namespace stream
 				m_SentPackets.insert (it);
 			}
 			SendPackets (packets);
-			if (m_Status == eStreamStatusClosing && m_SendBuffer.eof ())
+			if (m_Status == eStreamStatusClosing && m_SendBuffer.IsEmpty ())
 				SendClose ();
 			if (isEmpty)
 				ScheduleResend ();
@@ -525,7 +553,7 @@ namespace stream
 				Terminate ();
 			break;
 			case eStreamStatusClosing:
-				if (m_SentPackets.empty () && m_SendBuffer.eof ()) // nothing to send
+				if (m_SentPackets.empty () && m_SendBuffer.IsEmpty ()) // nothing to send
 				{
 					m_Status = eStreamStatusClosed;
 					SendClose ();

Streaming.h

@@ -3,7 +3,6 @@
 
 #include <inttypes.h>
 #include <string>
-#include <sstream>
 #include <map>
 #include <set>
 #include <queue>
@@ -104,6 +103,48 @@ namespace stream
 		};
 	};	
 
+	typedef std::function<void (const boost::system::error_code& ecode)> SendHandler;
+	struct SendBuffer
+	{
+		uint8_t * buf;
+		size_t len, offset;
+		SendHandler handler;
+
+		SendBuffer (const uint8_t * b, size_t l, SendHandler h):
+			len(l), offset (0), handler(h)
+		{
+			buf = new uint8_t[len];
+			memcpy (buf, b, len);
+		}	
+		~SendBuffer ()
+		{
+			delete[] buf;
+			if (handler) handler(boost::system::error_code ());
+		}	
+		size_t GetRemainingSize () const { return len - offset; };
+		const uint8_t * GetRemaningBuffer () const { return buf + offset; };	
+		void Cancel () { if (handler) handler (boost::asio::error::make_error_code (boost::asio::error::operation_aborted)); handler = nullptr; };
+	};	
+
+	class SendBufferQueue
+	{
+		public:
+
+			SendBufferQueue (): m_Size (0) {};
+			~SendBufferQueue () { CleanUp (); };
+
+			void Add (const uint8_t * buf, size_t len, SendHandler handler); 
+			size_t Get (uint8_t * buf, size_t len); 
+			size_t GetSize () const { return m_Size; };
+			bool IsEmpty () const { return m_Buffers.empty (); };
+			void CleanUp ();
+			
+		private:	
+
+			std::list<std::shared_ptr<SendBuffer> > m_Buffers;
+			size_t m_Size;
+	};	
+	
 	enum StreamStatus
 	{
 		eStreamStatusNew = 0,
@@ -118,8 +159,6 @@ namespace stream
 	{	
 		public:
 
-			typedef std::function<void (const boost::system::error_code& ecode)> SendHandler;
-
 			Stream (boost::asio::io_service& service, StreamingDestination& local, 
 				std::shared_ptr<const i2p::data::LeaseSet> remote, int port = 0); // outgoing
 			Stream (boost::asio::io_service& service, StreamingDestination& local); // incoming			
@@ -149,7 +188,7 @@ namespace stream
 			size_t GetNumReceivedBytes () const { return m_NumReceivedBytes; };
 			size_t GetSendQueueSize () const { return m_SentPackets.size (); };
 			size_t GetReceiveQueueSize () const { return m_ReceiveQueue.size (); };
-			size_t GetSendBufferSize () const { return m_SendBuffer.rdbuf ()->in_avail (); };
+			size_t GetSendBufferSize () const { return m_SendBuffer.GetSize (); };
 			int GetWindowSize () const { return m_WindowSize; };
 			int GetRTT () const { return m_RTT; };
 
@@ -202,11 +241,10 @@ namespace stream
 			uint16_t m_Port;
 
 			std::mutex m_SendBufferMutex;
-			std::stringstream m_SendBuffer;
+			SendBufferQueue m_SendBuffer;
 			int m_WindowSize, m_RTT, m_RTO;
 			uint64_t m_LastWindowSizeIncreaseTime;
 			int m_NumResendAttempts;
-			SendHandler m_SendHandler;
 	};
 
 	class StreamingDestination: public std::enable_shared_from_this<StreamingDestination>