nidas::core::MessageSampleScanner Class Reference

A DriverSampleScanner which supports the set/get of message separation parameters. More...

#include <SampleScanner.h>

Inheritance diagram for nidas::core::MessageSampleScanner:

Public Member Functions
	MessageSampleScanner (int bufsize=8192)
void	setMessageParameters (unsigned int len, const std::string &val, bool eom) throw (nidas::util::InvalidParameterException)
	Set the parameters which delineate a message for this scanner. 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
	Is the message separator at the end of the message (true), or at the beginning (false)? More...
unsigned int	getMessageLength () const
	Returns 0. More...
Sample *	nextSample (DSMSensor *sensor)
	Extract the next sample from the buffer. More...
virtual void	init ()
	Initialize the scanner. More...
virtual bool	getNullTerminate () const
	Should the SampleScanner append a null character, '\0', to the messages. More...
void	setUsecsPerByte (int val)
int	getUsecsPerByte () const
virtual size_t	readBuffer (DSMSensor *sensor, bool &exhausted) throw (nidas::util::IOException)
	Read from the sensor into the internal buffer of this SampleScanner. More...
virtual 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...
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 Attributes
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 DriverSampleScanner which supports the set/get of message separation parameters.

Typically these parameters are sent down to a driver module by an implementation of DSMSensor.

Constructor & Destructor Documentation

MessageSampleScanner::MessageSampleScanner

(

int

bufsize = 8192

)

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(), nidas::core::MessageStreamScanner::nextSampleByLength(), nidas::core::MessageStreamScanner::nextSampleSepBOM(), nidas::core::MessageStreamScanner::nextSampleSepEOM(), and nidas::core::MessageStreamScanner::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 MessageSampleScanner::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::MessageSampleScanner::getMessageLength ( ) const

inlinevirtual

Returns 0.

Reimplemented from nidas::core::SampleScanner.

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

const std::string& nidas::core::MessageSampleScanner::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::MessageSampleScanner::getMessageSeparatorAtEOM ( ) const

inlinevirtual

Is the message separator at the end of the message (true), or at the beginning (false)?

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().

virtual bool nidas::core::SampleScanner::getNullTerminate ( ) const

inlinevirtualinherited

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

Reimplemented in nidas::core::DatagramSampleScanner, and nidas::core::MessageStreamScanner.

Referenced by nidas::core::CharacterSensor::getNullTerminated().

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 nidas::core::MessageStreamScanner::nextSampleByLength(), nidas::core::MessageStreamScanner::nextSampleSepBOM(), and nidas::core::MessageStreamScanner::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 * DriverSampleScanner::nextSample ( DSMSensor *  sensor )

virtualinherited

Extract the next sample from the buffer.

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

Implements nidas::core::SampleScanner.

References nidas::core::SampleScanner::_buffer, nidas::core::SampleScanner::_bufhead, nidas::core::SampleScanner::_buftail, nidas::core::SampleScanner::_header, nidas::core::SampleScanner::_osamp, nidas::core::SampleScanner::_outSampDataPtr, nidas::core::SampleScanner::_outSampRead, nidas::core::SampleScanner::_outSampToRead, nidas::core::SampleClock::addSampleDate(), nidas::core::SampleScanner::addSampleToStats(), nidas::core::Sample::freeReference(), nidas::core::Sample::getDataByteLength(), nidas::core::DSMSensor::getDriverTimeTagUsecs(), nidas::core::DSMSensor::getId(), nidas::core::SampleClock::getInstance(), nidas::core::Sample::getVoidDataPtr(), nidas::core::SampleScanner::incrementBadTimeTags(), len, dsm_sample::length, nidas::core::SampleClock::OK, nidas::core::Sample::setDataLength(), nidas::core::Sample::setId(), nidas::core::Sample::setTimeTag(), SIZEOF_DSM_SAMPLE_HEADER, and dsm_sample::timetag.

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

virtualinherited

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

Reimplemented in nidas::core::DatagramSampleScanner, and nidas::core::MessageStreamScanner.

References DLOG, nidas::core::Project::getInstance(), and len.

Referenced by nidas::core::SampleScanner::readBuffer(), nidas::core::MessageStreamScanner::readBuffer(), and nidas::core::DSMSensor::readBuffer().

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

virtualinherited

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 in nidas::core::MessageStreamScanner.

References MSECS_PER_SEC, NLOG, NSECS_PER_MSEC, and nidas::core::SampleScanner::readBuffer().

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

virtual

Set the parameters which delineate a message for this scanner.

The messageSeparator is the string of bytes that a sensor outputs between messages. The string may contain baskslash sequences.

Parameters

len

The message length in bytes. A value of zero means the message length is completely variable, and that a scanner is should always be looking for a messageSeparator in the data. A positive value means read in messageLength number of bytes and then start looking for the messageSeparator. The messageLength does not include the length of the messageSeparator.

Setting a positive message length is only necessary if there is a chance that the message separator could be found in the data portion of the message. This may be the case if the sensor is generating binary data. A positive message length causes the parser to read messageLength number of bytes before again searching for the separator. This also makes the parsing a bit more efficient. If the messageLength is too small it will not necessarily cause messages to be truncated - all the data up to, and including the separator is still read and passed along for processing. If the value is larger than the actual message length it will cause two or more messages to be concatenated into one.

Parameters

eom

True means the message scanner expects the separator at the end of the message, and the next byte read after the separator is the first byte of the next message. The timetag of a sample is the receipt time of the first byte after the separator of the previous message. False means the scanner expects the separator at the beginning of the message, in which case the timetag of a sample is the receipt time of the first byte of the messageSeparator.

See Also

* nidas::util::replaceBackslashSequences()

Reimplemented from nidas::core::DriverSampleScanner.

References len, and nidas::util::replaceBackslashSequences().

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().

Member Data Documentation

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

protectedinherited

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

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

protectedinherited

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

int nidas::core::SampleScanner::_messageLength

protectedinherited

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

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

protectedinherited

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

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

protectedinherited

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

char* nidas::core::SampleScanner::_outSampDataPtr

protectedinherited

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

unsigned int nidas::core::SampleScanner::_outSampRead

protectedinherited

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

unsigned int nidas::core::SampleScanner::_outSampToRead

protectedinherited

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

char* nidas::core::SampleScanner::_separator

protectedinherited

messageSeparator in a C string.

Referenced by nidas::core::MessageStreamScanner::nextSampleSepBOM(), nidas::core::MessageStreamScanner::nextSampleSepEOM(), and nidas::core::SampleScanner::~SampleScanner().

bool nidas::core::SampleScanner::_separatorAtEOM

protectedinherited

Referenced by getMessageSeparatorAtEOM(), and nidas::core::MessageStreamScanner::getMessageSeparatorAtEOM().

int nidas::core::SampleScanner::_separatorLen

protectedinherited

Length of messageSeparator.

Referenced by nidas::core::MessageStreamScanner::nextSampleSepBOM(), and nidas::core::MessageStreamScanner::nextSampleSepEOM().

const unsigned int nidas::core::SampleScanner::BUFSIZE

protectedinherited

Buffer size for reading from sensor.

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The documentation for this class was generated from the following files:

• nidas/core/SampleScanner.h
• nidas/core/SampleScanner.cc