ext-cryptopp/network.h

#ifndef CRYPTOPP_NETWORK_H
#define CRYPTOPP_NETWORK_H

#include "filters.h"
#include "hrtimer.h"

NAMESPACE_BEGIN(CryptoPP)

//! a Source class that can pump from a device for a specified amount of time.
class CRYPTOPP_NO_VTABLE NonblockingSource : public AutoSignaling<Source>
{
public:
	NonblockingSource(BufferedTransformation *attachment)
		: m_messageEndSent(false) {Detach(attachment);}

	//!	\name NONBLOCKING SOURCE
	//@{

	//! pump up to maxSize bytes using at most maxTime milliseconds
	/*! If checkDelimiter is true, pump up to delimiter, which itself is not extracted or pumped. */
	virtual unsigned int GeneralPump2(unsigned long &byteCount, bool blockingOutput=true, unsigned long maxTime=INFINITE_TIME, bool checkDelimiter=false, byte delimiter='\n') =0;

	unsigned long GeneralPump(unsigned long maxSize=ULONG_MAX, unsigned long maxTime=INFINITE_TIME, bool checkDelimiter=false, byte delimiter='\n')
	{
		GeneralPump2(maxSize, true, maxTime, checkDelimiter, delimiter);
		return maxSize;
	}
	unsigned long TimedPump(unsigned long maxTime)
		{return GeneralPump(ULONG_MAX, maxTime);}
	unsigned long PumpLine(byte delimiter='\n', unsigned long maxSize=1024)
		{return GeneralPump(maxSize, INFINITE_TIME, true, delimiter);}

	unsigned int Pump2(unsigned long &byteCount, bool blocking=true)
		{return GeneralPump2(byteCount, blocking, blocking ? INFINITE_TIME : 0);}
	unsigned int PumpMessages2(unsigned int &messageCount, bool blocking=true);
	//@}

private:
	bool m_messageEndSent;
};

//! Network Receiver
class CRYPTOPP_NO_VTABLE NetworkReceiver : public Waitable
{
public:
	virtual bool MustWaitToReceive() {return false;}
	virtual bool MustWaitForResult() {return false;}
	//! receive data from network source, returns whether result is immediately available
	virtual bool Receive(byte* buf, unsigned int bufLen) =0;
	virtual unsigned int GetReceiveResult() =0;
	virtual bool EofReceived() const =0;
};

class CRYPTOPP_NO_VTABLE NonblockingSinkInfo
{
public:
	virtual ~NonblockingSinkInfo() {}
	virtual unsigned int GetMaxBufferSize() const =0;
	virtual unsigned int GetCurrentBufferSize() const =0;
	//! compute the current speed of this sink in bytes per second
	virtual float ComputeCurrentSpeed() =0;
	//! get the maximum observed speed of this sink in bytes per second
	virtual float GetMaxObservedSpeed() const =0;
};

//! a Sink class that queues input and can flush to a device for a specified amount of time.
class CRYPTOPP_NO_VTABLE NonblockingSink : public Sink, public NonblockingSinkInfo
{
public:
	bool IsolatedFlush(bool hardFlush, bool blocking);

	//! flush to device for no more than maxTime milliseconds
	/*! This function will repeatedly attempt to flush data to some device, until
		the queue is empty, or a total of maxTime milliseconds have elapsed.
		If maxTime == 0, at least one attempt will be made to flush some data, but
		it is likely that not all queued data will be flushed, even if the device
		is ready to receive more data without waiting. If you want to flush as much data
		as possible without waiting for the device, call this function in a loop.
		For example: while (sink.TimedFlush(0) > 0) {}
		\return number of bytes flushed
	*/
	virtual unsigned int TimedFlush(unsigned long maxTime, unsigned int targetSize = 0) =0;

	virtual void SetMaxBufferSize(unsigned int maxBufferSize) =0;
	//! set a bound which will cause sink to flush if exceeded by GetCurrentBufferSize()
	virtual void SetAutoFlushBound(unsigned int bound) =0;
};

//! Network Sender
class CRYPTOPP_NO_VTABLE NetworkSender : public Waitable
{
public:
	virtual bool MustWaitToSend() {return false;}
	virtual bool MustWaitForResult() {return false;}
	virtual void Send(const byte* buf, unsigned int bufLen) =0;
	virtual unsigned int GetSendResult() =0;
	virtual void SendEof() =0;
};

#ifdef HIGHRES_TIMER_AVAILABLE

//! Network Source
class CRYPTOPP_NO_VTABLE NetworkSource : public NonblockingSource
{
public:
	NetworkSource(BufferedTransformation *attachment);

	unsigned int GetMaxWaitObjectCount() const
		{return GetReceiver().GetMaxWaitObjectCount() + AttachedTransformation()->GetMaxWaitObjectCount();}
	void GetWaitObjects(WaitObjectContainer &container);

	unsigned int GeneralPump2(unsigned long &byteCount, bool blockingOutput=true, unsigned long maxTime=INFINITE_TIME, bool checkDelimiter=false, byte delimiter='\n');
	bool SourceExhausted() const {return m_dataBegin == m_dataEnd && GetReceiver().EofReceived();}

protected:
	virtual NetworkReceiver & AccessReceiver() =0;
	const NetworkReceiver & GetReceiver() const {return const_cast<NetworkSource *>(this)->AccessReceiver();}

private:
	SecByteBlock m_buf;
	unsigned int m_putSize, m_dataBegin, m_dataEnd;
	bool m_waitingForResult, m_outputBlocked;
};

//! Network Sink
class CRYPTOPP_NO_VTABLE NetworkSink : public NonblockingSink
{
public:
	NetworkSink(unsigned int maxBufferSize, unsigned int autoFlushBound);

	unsigned int GetMaxWaitObjectCount() const
		{return GetSender().GetMaxWaitObjectCount();}
	void GetWaitObjects(WaitObjectContainer &container)
		{if (m_wasBlocked || !m_buffer.IsEmpty()) AccessSender().GetWaitObjects(container);}

	unsigned int Put2(const byte *inString, unsigned int length, int messageEnd, bool blocking);

	unsigned int TimedFlush(unsigned long maxTime, unsigned int targetSize = 0);

	void SetMaxBufferSize(unsigned int maxBufferSize) {m_maxBufferSize = maxBufferSize; m_buffer.SetNodeSize(STDMIN(16U*1024U+256, maxBufferSize));}
	void SetAutoFlushBound(unsigned int bound) {m_autoFlushBound = bound;}

	unsigned int GetMaxBufferSize() const {return m_maxBufferSize;}
	unsigned int GetCurrentBufferSize() const {return m_buffer.CurrentSize();}

	void ClearBuffer() {m_buffer.Clear();}

	//! compute the current speed of this sink in bytes per second
	float ComputeCurrentSpeed();
	//! get the maximum observed speed of this sink in bytes per second
	float GetMaxObservedSpeed() const {return m_maxObservedSpeed;}

protected:
	virtual NetworkSender & AccessSender() =0;
	const NetworkSender & GetSender() const {return const_cast<NetworkSink *>(this)->AccessSender();}

private:
	unsigned int m_maxBufferSize, m_autoFlushBound;
	bool m_needSendResult, m_wasBlocked;
	ByteQueue m_buffer;
	unsigned int m_skipBytes;
	Timer m_speedTimer;
	float m_byteCountSinceLastTimerReset, m_currentSpeed, m_maxObservedSpeed;
};

#endif	// #ifdef HIGHRES_TIMER_AVAILABLE

NAMESPACE_END

#endif