pip/libs/main/io_utils/pipacketextractor.h

/*! \file pipacketextractor.h
 * \ingroup IO
 * \~\brief
 * \~english Packets extractor
 * \~russian Извлекатель пакетов
 */
/*
    PIP - Platform Independent Primitives
    Packets extractor
    Ivan Pelipenko peri4ko@yandex.ru, Andrey Bychkov work.a.b@yandex.ru

    This program 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.

    This program 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 a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef PIPACKETEXTRACTOR_H
#define PIPACKETEXTRACTOR_H

#include "piiodevice.h"

/// TODO: написать документацию, тут ничего не понятно
/// Pass SourceHeaderPtr, ReceivedHeaderPtr, HeaderSize.
/// Return size of payload if packet is correct, or -1 if incorrect.
typedef std::function<int(const uchar *, const uchar *, int)> PacketExtractorHeaderFunc;

/// Pass ReceivedDataPtr, DataSize.
/// Return true if packet is correct, false otherwise.
typedef std::function<bool(const uchar *, int)> PacketExtractorPayloadFunc;

/// Pass SourceFooterPtr, ReceivedFooterPtr, FooterSize.
/// Return true if packet is correct, false otherwise.
typedef std::function<bool(const uchar *, const uchar *, int)> PacketExtractorFooterFunc;

class PIP_EXPORT PIPacketExtractor: public PIIODevice {
	PIIODEVICE(PIPacketExtractor, "pckext");
	friend class PIConnection;

public:
	//! Extract algorithms
	enum SplitMode {
		None /** No data processing */,
		Header /** Detect packets with \a header() and following \a payloadSize() */,
		Footer /** Detect packets with \a footer() and leading \a payloadSize() */,
		HeaderAndFooter /** Detect packets with \a header() and \a footer() without \a payloadSize() */,
		Size /** Detect packets with \a packetSize() */,
		Timeout /** Wait for first read, then read for \a timeout() milliseconds */
	};

	//! Contructs extractor with child device "device_" and extract algorithm "mode"
	explicit PIPacketExtractor(PIIODevice * device_ = nullptr, SplitMode mode = None);

	virtual ~PIPacketExtractor() { stop(); }


	//! Returns child %device
	PIIODevice * device() { return dev; }

	//! Set child %device to "device_"
	void setDevice(PIIODevice * device_);

	ssize_t bytesAvailable() const override;

	void setHeaderCheckSlot(PacketExtractorHeaderFunc f) { func_header = f; }
	void setPayloadCheckSlot(PacketExtractorPayloadFunc f) { func_payload = f; }
	void setFooterCheckSlot(PacketExtractorFooterFunc f) { func_footer = f; }


	//! Set extract algorithm
	void setSplitMode(SplitMode mode) { setProperty("splitMode", int(mode)); }

	//! Set payload size, used for PIPacketExtractor::Header and PIPacketExtractor::Footer algorithms
	void setPayloadSize(int size);

	//! Set header data, used for PIPacketExtractor::Header and PIPacketExtractor::HeaderAndFooter algorithms
	void setHeader(const PIByteArray & data);

	//! Set footer data, used for PIPacketExtractor::Footer and PIPacketExtractor::HeaderAndFooter algorithms
	void setFooter(const PIByteArray & data);

	//! Set timeout in milliseconds, used for PIPacketExtractor::Timeout algorithm
	void setTimeout(double msecs) { setProperty("timeout", msecs); }


	//! Returns current extract algorithm
	SplitMode splitMode() const { return mode_; }

	//! Returns current payload size, used for PIPacketExtractor::Header and PIPacketExtractor::Footer and PIPacketExtractor::Size
	//! algorithms
	int payloadSize() const { return dataSize; }

	//! Returns current header data, used for PIPacketExtractor::Header and PIPacketExtractor::HeaderAndFooter algorithms
	PIByteArray header() const { return src_header; }

	//! Returns current footer data, used for PIPacketExtractor::Footer and PIPacketExtractor::HeaderAndFooter algorithms
	PIByteArray footer() const { return src_footer; }

	//! Returns current timeout in milliseconds, used for PIPacketExtractor::Timeout algorithm
	double timeout() const { return time_; }

	//! Returns missed by validating functions bytes count
	ullong missedBytes() const { return missed; }

	//! Add data to extractor, raise \a packetReceived() if packet is ready
	void appendData(const uchar * d, int s) { threadedRead(d, s); }

	//! Add data to extractor, raise \a packetReceived() if packet is ready
	void appendData(const PIByteArray & data) { threadedRead(data.data(), data.size_s()); }

	EVENT2(packetReceived, const uchar *, data, int, size);

	//! \events
	//! \{

	//! \fn void packetReceived(const uchar * data, int size)
	//! \brief Raise on successfull \a packetValidate() function

	//! \}

protected:
	/** \brief Function to validate header
	 * \param src Your header content
	 * \param rec Received header
	 * \param size Header size
	 * \details Default implementation returns by-byte "src" with "rec" compare result */
	virtual int validateHeader(const uchar * src, const uchar * rec, int size);

	/** \brief Function to validate footer
	 * \param src Your footer content
	 * \param rec Received footer
	 * \param size Footer size
	 * \details Default implementation returns by-byte "src" with "rec" compare result */
	virtual bool validateFooter(const uchar * src, const uchar * rec, int size);

	/** \brief Function to validate payload
	 * \param rec Received payload
	 * \param size payload size
	 * \details Default implementation returns \b true */
	virtual bool validatePayload(const uchar * rec, int size);

private:
	void construct();
	void propertyChanged(const char *) override;
	ssize_t readDevice(void * read_to, ssize_t max_size) override;
	ssize_t writeDevice(const void * data, ssize_t max_size) override;
	bool threadedRead(const uchar * readed, ssize_t size) override;
	PIString constructFullPathDevice() const override;
	bool openDevice() override;
	bool closeDevice() override;
	DeviceInfoFlags deviceInfoFlags() const override;

	PIIODevice * dev;
	PIByteArray src_header, src_footer, tmpbuf;
	PacketExtractorHeaderFunc func_header;
	PacketExtractorPayloadFunc func_payload;
	PacketExtractorFooterFunc func_footer;
	SplitMode mode_;
	int dataSize, packetSize_pending, footerInd;
	double time_;
	bool header_found;
	ullong missed;
};

#endif // PIPACKETEXTRACTOR_H