A SampleScanner which supports the set/get of message separation parameters and extracts samples from the internal buffer by recognizing separators in the message stream. More...

#include <SampleScanner.h>

Inheritance diagram for nidas::core::MessageStreamScanner:

[legend]

Public Member Functions
	MessageStreamScanner (int bufsize=4096)

void	setMessageParameters (unsigned int len, const std::string &val, bool eom) throw (nidas::util::InvalidParameterException)
	Set the parameters associated with scanning of character messages. More...

const std::string &	getMessageSeparator () const
	Get message separator string. More...

const std::string	getBackslashedMessageSeparator () const
	Get message separator with backslash sequences added back. More...

bool	getMessageSeparatorAtEOM () const

unsigned int	getMessageLength () const
	Returns 0. More...

void	setNullTerminate (bool val)

bool	getNullTerminate () const
	Should the SampleScanner append a null character, '\0', to the messages. More...

Sample *	nextSample (DSMSensor *sensor)
	Extract the next sample from the buffer. More...

size_t	readBuffer (DSMSensor *sensor, bool &exhausted) throw (nidas::util::IOException)
	Read from the sensor into the internal buffer of this SampleScanner. More...

size_t	readBuffer (DSMSensor *sensor, bool &exhausted, int msecTimeout) throw (nidas::util::IOException)
	Read from the sensor into the internal buffer of this SampleScanner, providing a timeout in milliseconds. More...

void	warnNonIncrTimeTag (const DSMSensor *sensor, dsm_time_t badtt, dsm_time_t cortt, unsigned int nbad)
	Issue warning log message about a non-forward time tag. More...

void	warnBackwardsStepTimeTag (const DSMSensor *sensor, dsm_time_t badtt, unsigned int nbad)

virtual void	init ()
	Initialize the scanner. More...

void	setUsecsPerByte (int val)

int	getUsecsPerByte () const

virtual void	clearBuffer ()

unsigned int	getBytesInBuffer () const

virtual void	resetStatistics ()

virtual void	calcStatistics (unsigned int periodUsec)
	Update the sensor sampling statistics: samples/sec, bytes/sec, min/max sample size, that can be accessed via getObservedSamplingRate(), getObservedDataRate() etc. More...

unsigned int	getMaxSampleLength () const

unsigned int	getMinSampleLength () const

unsigned int	getBadTimeTagCount () const

float	getObservedSamplingRate () const

float	getObservedDataRate () const

void	addNumBytesToStats (size_t val)

void	addSampleToStats (unsigned int val)

void	incrementBadTimeTags ()

Protected Member Functions
virtual Sample *	nextSampleSepBOM (DSMSensor *sensor)
	Method to read input and break it into samples where the message separator occurs at the beginning of the message. More...

virtual Sample *	nextSampleSepEOM (DSMSensor *sensor)
	Method to read input and break it into samples where the message separator occurs at the end of the message. More...

Sample *	nextSampleByLength (DSMSensor *sensor)
	Method to read input and break it into samples strictly by record length. More...

Sample *	requestBiggerSample (unsigned int nc)
	If a new sample can be allocated without exceeding MAX_MESSAGE_STREAM_SAMPLE_SIZE then get a new, larger sample, copying the timetag, id and existing data from the current sample, and return null. More...

Protected Attributes
Sample (MessageStreamScanner::	_nextSampleFunc )(DSMSensor *)

dsm_time_t	_tfirstchar

dsm_time_t	_lastBufferTime

dsm_time_t	_lastSampleTime

const unsigned int	MAX_MESSAGE_STREAM_SAMPLE_SIZE

int	_separatorCnt

dsm_time_t	_bomtt

int	_sampleOverflows

unsigned int	_sampleLengthAlloc
	Size of samples to allocate. More...

bool	_nullTerminate

int	_nsmallSamples
	Count of number of consecutive samples smaller than _sampleLengthAlloc. More...

unsigned int	_outSampLengthAlloc
	Number of bytes allocated in data portion of current output sample. More...

bool	_stepBackwards
	If the system time of a buffer read is earlier than the previous read. More...

unsigned int	_stepBackTimeTag
	Number of time tags that were not monotonically increasing, due to backward step changes. More...

unsigned int	_nonIncrTimeTag
	Number of time tags that were not monotonically increasing, not because of backward step changes, but instead due to system buffering, where the receipt times of two buffers are closer together than should be possible at the given baud rate. More...

const unsigned int	BUFSIZE
	Buffer size for reading from sensor. More...

char *	_buffer

unsigned int	_bufhead

unsigned int	_buftail

Sample *	_osamp

struct dsm_sample	_header

unsigned int	_outSampRead

unsigned int	_outSampToRead

char *	_outSampDataPtr

std::string	_messageSeparator

int	_messageLength

bool	_separatorAtEOM

char *	_separator
	messageSeparator in a C string. More...

int	_separatorLen
	Length of messageSeparator. More...

Detailed Description

A SampleScanner which supports the set/get of message separation parameters and extracts samples from the internal buffer by recognizing separators in the message stream.

Timetags are applied to the samples based on the time of receipt of each chunk of data, corrected backwards by the computed tranmission time of each byte in the chunk.

See Also: setUsecsPerByte().

Constructor & Destructor Documentation

MessageStreamScanner::MessageStreamScanner ( int bufsize = 4096 )

Member Function Documentation

void nidas::core::SampleScanner::addNumBytesToStats ( size_t val )

inlineinherited

References nidas::core::SampleScanner::_nbytes.

void nidas::core::SampleScanner::addSampleToStats ( unsigned int val )

inlineinherited

References nidas::core::SampleScanner::_currentIndex, nidas::core::SampleScanner::_maxSampleLength, nidas::core::SampleScanner::_minSampleLength, and nidas::core::SampleScanner::_nsamples.

Referenced by nidas::core::DriverSampleScanner::nextSample(), nidas::core::DatagramSampleScanner::nextSample(), nextSampleByLength(), nextSampleSepBOM(), nextSampleSepEOM(), and requestBiggerSample().

void SampleScanner::calcStatistics ( unsigned int periodUsec )

virtualinherited

Update the sensor sampling statistics: samples/sec, bytes/sec, min/max sample size, that can be accessed via getObservedSamplingRate(), getObservedDataRate() etc.

Should be called every periodUsec by a user of this sensor.

Parameters

periodUsec Statistics period.

References nidas::core::SampleScanner::_currentIndex, nidas::core::SampleScanner::_dataRateObs, nidas::core::SampleScanner::_maxSampleLength, nidas::core::SampleScanner::_minSampleLength, nidas::core::SampleScanner::_nbytes, nidas::core::SampleScanner::_nsamples, nidas::core::SampleScanner::_reportIndex, nidas::core::SampleScanner::_sampleRateObs, and USECS_PER_SEC.

Referenced by nidas::core::DSMSensor::calcStatistics().

void SampleScanner::clearBuffer ( )

virtualinherited

References nidas::core::SampleScanner::_bufhead, and nidas::core::SampleScanner::_buftail.

Referenced by nidas::core::DSMSensor::clearBuffer().

const string MessageStreamScanner::getBackslashedMessageSeparator ( ) const

virtual

Get message separator with backslash sequences added back.

Reimplemented from nidas::core::SampleScanner.

References nidas::core::SampleScanner::_messageSeparator, and nidas::util::addBackslashSequences().

unsigned int nidas::core::SampleScanner::getBadTimeTagCount ( ) const

inlineinherited

References nidas::core::SampleScanner::_badTimeTags.

Referenced by nidas::core::DSMSensor::getBadTimeTagCount().

unsigned int nidas::core::SampleScanner::getBytesInBuffer ( ) const

inlineinherited

References nidas::core::SampleScanner::_bufhead, and nidas::core::SampleScanner::_buftail.

unsigned int nidas::core::SampleScanner::getMaxSampleLength ( ) const

inlineinherited

References nidas::core::SampleScanner::_maxSampleLength, and nidas::core::SampleScanner::_reportIndex.

Referenced by nidas::core::DSMSensor::getMaxSampleLength().

unsigned int nidas::core::MessageStreamScanner::getMessageLength ( ) const

inlinevirtual

Returns 0.

Reimplemented from nidas::core::SampleScanner.

References nidas::core::SampleScanner::_messageLength.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

const std::string& nidas::core::MessageStreamScanner::getMessageSeparator ( ) const

inlinevirtual

Get message separator string.

Any backslash sequences will have been replaced by their intended value.

Reimplemented from nidas::core::SampleScanner.

References nidas::core::SampleScanner::_messageSeparator.

bool nidas::core::MessageStreamScanner::getMessageSeparatorAtEOM ( ) const

inlinevirtual

Reimplemented from nidas::core::SampleScanner.

References nidas::core::SampleScanner::_separatorAtEOM.

unsigned int nidas::core::SampleScanner::getMinSampleLength ( ) const

inlineinherited

References nidas::core::SampleScanner::_maxSampleLength, nidas::core::SampleScanner::_minSampleLength, and nidas::core::SampleScanner::_reportIndex.

Referenced by nidas::core::DSMSensor::getMinSampleLength().

bool nidas::core::MessageStreamScanner::getNullTerminate ( ) const

inlinevirtual

Should the SampleScanner append a null character, '\0', to the messages.

Reimplemented from nidas::core::SampleScanner.

References _nullTerminate.

Referenced by nextSampleSepBOM(), nextSampleSepEOM(), and requestBiggerSample().

float SampleScanner::getObservedDataRate ( ) const

inherited

References nidas::core::SampleScanner::_currentIndex, nidas::core::SampleScanner::_dataRateObs, nidas::core::SampleScanner::_initialTimeSecs, nidas::core::SampleScanner::_nbytes, and nidas::core::SampleScanner::_reportIndex.

Referenced by nidas::core::DSMSensor::getObservedDataRate().

float SampleScanner::getObservedSamplingRate ( ) const

inherited

References nidas::core::SampleScanner::_currentIndex, nidas::core::SampleScanner::_initialTimeSecs, nidas::core::SampleScanner::_nsamples, nidas::core::SampleScanner::_reportIndex, and nidas::core::SampleScanner::_sampleRateObs.

Referenced by nidas::core::DSMSensor::getObservedSamplingRate().

int nidas::core::SampleScanner::getUsecsPerByte ( ) const

inlineinherited

References nidas::core::SampleScanner::_usecsPerByte.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

void nidas::core::SampleScanner::incrementBadTimeTags ( )

inlineinherited

References nidas::core::SampleScanner::_badTimeTags.

Referenced by nidas::core::DriverSampleScanner::nextSample().

void SampleScanner::init ( )

virtualinherited

Initialize the scanner.

Must be called by a user of SampleScanner prior to calling readSamples().

References nidas::core::SampleScanner::resetStatistics().

Sample* nidas::core::MessageStreamScanner::nextSample ( DSMSensor * sensor )

inlinevirtual

Extract the next sample from the buffer.

Returns NULL if there are no more samples in the buffer.

Implements nidas::core::SampleScanner.

References _nextSampleFunc.

Sample * MessageStreamScanner::nextSampleByLength ( DSMSensor * sensor )

protected

Method to read input and break it into samples strictly by record length.

Referenced by setMessageParameters().

Sample * MessageStreamScanner::nextSampleSepBOM ( DSMSensor * sensor )

protectedvirtual

Method to read input and break it into samples where the message separator occurs at the beginning of the message.

Referenced by setMessageParameters().

Sample * MessageStreamScanner::nextSampleSepEOM ( DSMSensor * sensor )

protectedvirtual

Method to read input and break it into samples where the message separator occurs at the end of the message.

Referenced by setMessageParameters().

size_t MessageStreamScanner::readBuffer	(	DSMSensor *	sensor,
		bool &	exhausted
	)
throw	(	nidas::util::IOException
	)

virtual

Read from the sensor into the internal buffer of this SampleScanner.

Reimplemented from nidas::core::SampleScanner.

References nidas::util::getSystemTime(), and nidas::core::SampleScanner::readBuffer().

size_t MessageStreamScanner::readBuffer	(	DSMSensor *	sensor,
		bool &	exhausted,
		int	msecTimeout
	)
throw	(	nidas::util::IOException
	)

virtual

Read from the sensor into the internal buffer of this SampleScanner, providing a timeout in milliseconds.

This will throw nidas::util::IOTimeoutException if the read fails due to a timeout.

Reimplemented from nidas::core::SampleScanner.

References nidas::util::getSystemTime(), and nidas::core::SampleScanner::readBuffer().

Sample * MessageStreamScanner::requestBiggerSample ( unsigned int nc )

protected

If a new sample can be allocated without exceeding MAX_MESSAGE_STREAM_SAMPLE_SIZE then get a new, larger sample, copying the timetag, id and existing data from the current sample, and return null.

The data members _osamp, and _outSampDataPtr are updated to point to the new sample. Otherwise, since we've reached the MAX limit, more data will not be added to the sample, so return a pointer to the existing max'd out sample, which should then be returned as the value of the nextSample() method.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

void SampleScanner::resetStatistics ( )

virtualinherited

References nidas::core::SampleScanner::_badTimeTags, nidas::core::SampleScanner::_currentIndex, nidas::core::SampleScanner::_dataRateObs, nidas::core::SampleScanner::_initialTimeSecs, nidas::core::SampleScanner::_maxSampleLength, nidas::core::SampleScanner::_minSampleLength, nidas::core::SampleScanner::_nbytes, nidas::core::SampleScanner::_nsamples, nidas::core::SampleScanner::_reportIndex, and nidas::core::SampleScanner::_sampleRateObs.

Referenced by nidas::core::SampleScanner::init(), and nidas::core::SampleScanner::SampleScanner().

void MessageStreamScanner::setMessageParameters	(	unsigned int	len,
		const std::string &	val,
		bool	eom
	)
throw	(	nidas::util::InvalidParameterException
	)

virtual

Set the parameters associated with scanning of character messages.

Implements nidas::core::SampleScanner.

References len, nextSampleByLength(), nextSampleSepBOM(), nextSampleSepEOM(), and nidas::util::replaceBackslashSequences().

Referenced by nidas::dynld::GPS_NMEA_Serial::buildSampleScanner().

void nidas::core::MessageStreamScanner::setNullTerminate ( bool val )

inline

References _nullTerminate.

Referenced by nidas::core::CharacterSensor::buildSampleScanner(), and nidas::dynld::GPS_NMEA_Serial::buildSampleScanner().

void nidas::core::SampleScanner::setUsecsPerByte ( int val )

inlineinherited

References nidas::core::SampleScanner::_usecsPerByte.

Referenced by nidas::core::SerialSensor::buildSampleScanner(), and nidas::dynld::GPS_NMEA_Serial::buildSampleScanner().

void MessageStreamScanner::warnBackwardsStepTimeTag	(	const DSMSensor *	sensor,
		dsm_time_t	badtt,
		unsigned int	nbad
	)

References nidas::util::UTime::format(), nidas::core::DSMSensor::getDSMId(), nidas::core::DSMSensor::getName(), nidas::core::DSMSensor::getSensorId(), and WLOG.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

void MessageStreamScanner::warnNonIncrTimeTag	(	const DSMSensor *	sensor,
		dsm_time_t	badtt,
		dsm_time_t	cortt,
		unsigned int	nbad
	)

Issue warning log message about a non-forward time tag.

References nidas::util::UTime::format(), nidas::core::DSMSensor::getDSMId(), nidas::core::DSMSensor::getName(), nidas::core::DSMSensor::getSensorId(), USECS_PER_SEC, and WLOG.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

Member Data Documentation

dsm_time_t nidas::core::MessageStreamScanner::_bomtt

protected

Referenced by nextSampleSepBOM().

char* nidas::core::SampleScanner::_buffer

protectedinherited

Referenced by nidas::core::DriverSampleScanner::nextSample(), nidas::core::DatagramSampleScanner::nextSample(), nextSampleByLength(), nextSampleSepBOM(), nextSampleSepEOM(), and nidas::core::SampleScanner::~SampleScanner().

unsigned int nidas::core::SampleScanner::_bufhead

protectedinherited

Referenced by nidas::core::SampleScanner::clearBuffer(), nidas::core::SampleScanner::getBytesInBuffer(), nidas::core::DriverSampleScanner::nextSample(), nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

unsigned int nidas::core::SampleScanner::_buftail

protectedinherited

Referenced by nidas::core::SampleScanner::clearBuffer(), nidas::core::SampleScanner::getBytesInBuffer(), nidas::core::DriverSampleScanner::nextSample(), nidas::core::DatagramSampleScanner::nextSample(), nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

struct dsm_sample nidas::core::SampleScanner::_header

protectedinherited

Referenced by nidas::core::DriverSampleScanner::nextSample().

dsm_time_t nidas::core::MessageStreamScanner::_lastBufferTime

protected

dsm_time_t nidas::core::MessageStreamScanner::_lastSampleTime

protected

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

int nidas::core::SampleScanner::_messageLength

protectedinherited

Referenced by nidas::core::MessageSampleScanner::getMessageLength(), and getMessageLength().

std::string nidas::core::SampleScanner::_messageSeparator

protectedinherited

Referenced by nidas::core::MessageSampleScanner::getBackslashedMessageSeparator(), getBackslashedMessageSeparator(), nidas::core::MessageSampleScanner::getMessageSeparator(), and getMessageSeparator().

Sample*(MessageStreamScanner::* nidas::core::MessageStreamScanner::_nextSampleFunc)(DSMSensor *)

protected

Referenced by nextSample().

unsigned int nidas::core::MessageStreamScanner::_nonIncrTimeTag

protected

Number of time tags that were not monotonically increasing, not because of backward step changes, but instead due to system buffering, where the receipt times of two buffers are closer together than should be possible at the given baud rate.

Referenced by nextSampleByLength(), nextSampleSepBOM(), and nextSampleSepEOM().

int nidas::core::MessageStreamScanner::_nsmallSamples

protected

Count of number of consecutive samples smaller than _sampleLengthAlloc.

Referenced by nextSampleSepBOM(), and nextSampleSepEOM().

bool nidas::core::MessageStreamScanner::_nullTerminate

protected

Referenced by getNullTerminate(), and setNullTerminate().

Sample* nidas::core::SampleScanner::_osamp

protectedinherited

Referenced by nidas::core::DriverSampleScanner::nextSample(), nextSampleByLength(), nextSampleSepBOM(), nextSampleSepEOM(), requestBiggerSample(), and nidas::core::SampleScanner::~SampleScanner().