#include <SyncRecordSource.h>

Inheritance diagram for nidas::dynld::raf::SyncRecordSource:

Public Member Functions
	SyncRecordSource ()
	SyncRecordSource builds "sync records" from a sample stream. More...

virtual	~SyncRecordSource ()

SampleSource *	getRawSampleSource ()
	Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples. More...

SampleSource *	getProcessedSampleSource ()
	Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples. More...

std::list< const SampleTag * >	getSampleTags () const
	Get the output SampleTags. More...

SampleTagIterator	getSampleTagIterator () const
	Implementation of SampleSource::getSampleTagIterator(). More...

void	addSampleClient (SampleClient *client) throw ()
	Implementation of SampleSource::addSampleClient(). More...

void	removeSampleClient (SampleClient *client) throw ()
	Remove a SampleClient from this SampleSource. More...

void	addSampleClientForTag (SampleClient client, const SampleTag ) throw ()
	Add a Client for a given SampleTag. More...

void	removeSampleClientForTag (SampleClient client, const SampleTag ) throw ()
	Remove a SampleClient for a given SampleTag from this SampleSource. More...

int	getClientCount () const throw ()
	How many SampleClients are currently in my list. More...

void	flush () throw ()
	Implementation of Resampler::flush(). More...

const SampleStats &	getSampleStats () const

void	connect (SampleSource *source) throw ()
	Connect the resampler to a source. More...

void	disconnect (SampleSource *source) throw ()

void	init ()
	Create the SyncInfo objects for all samples and their variables that will go in the sync record. More...

void	sendSyncHeader () throw ()
	Generate and send a sync record header sample. More...

bool	receive (const Sample *) throw ()
	Method called to pass a sample to this client. More...

void	preLoadCalibrations (dsm_time_t sampleTime) throw ()

bool	prevRecord (SyncInfo &sinfo)
	If the previous sync record is non-null, do sinfo.decrementRecord(). More...

bool	nextRecord (SyncInfo &sinfo)
	If the next sync record is non-null, do sinfo.incrementRecord(). More...

int	computeSlotIndex (const Sample *samp, SyncInfo &sinfo)
	Which time slot should a sample be placed. More...

Static Public Member Functions
static void	selectVariablesFromProject (Project project, std::list< const Variable > &variables)
	This method and selectVariablesFromSensor() are used to select the list of variables from a Project configuration in order of sensor, with variables in order for each sensor, accepting only the variables which make sense for Aircraft SyncRecords. More...

static void	selectVariablesFromSensor (DSMSensor sensor, std::list< const Variable > &variables)
	See selectVariablesFromProject(). More...

static int	nextRecordIndex (int i)
	Return the index of the next sync record. More...

static int	prevRecordIndex (int i)
	Return the index of the previous sync record. More...

Static Public Attributes
static const int	NSLOT_LIMIT = 2
	Maximum number of delta-Ts allowed between a sample time tag and its slot in the sync record. More...

static const int	NSYNCREC = 2

Private Member Functions
bool	checkTime (const Sample *samp, SyncInfo &sinfo, SampleTracer &stracer, nidas::util::LogContext &lc, int warn_times)

void	slog (SampleTracer &stracer, const std::string &msg, const Sample *samp, const SyncInfo &sinfo)

void	log (nidas::util::LogContext &lc, const std::string &msg, const Sample *samp, const SyncInfo &sinfo)

void	log (nidas::util::LogContext &lc, const std::string &msg, const SyncInfo &sinfo)

void	addSampleTag (const SampleTag *tag) throw ()
	Add a SampleTag to this SampleSource. More...

void	removeSampleTag (const SampleTag *tag) throw ()

void	createHeader (std::ostream &) throw ()

void	sendSyncRecord ()

void	allocateRecord (int irec, dsm_time_t timetag)

int	advanceRecord (dsm_time_t timetag)

	SyncRecordSource (const SyncRecordSource &)
	No copying. More...

SyncRecordSource &	operator= (const SyncRecordSource &)
	No assignment. More...

Private Attributes
SampleSourceSupport	_source

std::map< dsm_sample_id_t, SyncInfo >	_syncInfo
	Info kept for each sample in order to assemble and write sync records. More...

std::list< const Variable * >	_variables
	List of all variables in the sync record. More...

SampleTag	_syncRecordHeaderSampleTag

SampleTag	_syncRecordDataSampleTag

size_t	_recSize

dsm_time_t	_syncHeaderTime

dsm_time_t	_syncTime [2]

int	_current
	Index of current sync record. More...

int	_halfMaxUsecsPerSample

SampleT< double > *	_syncRecord [2]

double *	_dataPtr [2]

size_t	_unrecognizedSamples

std::ostringstream	_headerStream

const Aircraft *	_aircraft

bool	_initialized

int	_unknownSampleType

unsigned int	_badLaterSamples

Constructor & Destructor Documentation

SyncRecordSource::SyncRecordSource ( )

SyncRecordSource builds "sync records" from a sample stream.

This is a lossy process whete data is being munged into a one-second, ragged matrix of double precision values, called a sync record. Each row of the matrix contains the data for the variables with a given sample id. In NIDAS, a sample is a group of variables all with the same timetag. In order to build sync records a sample also must have a known sampling rate, SampleTag::getRate().

Each row of the matrix is formatted as follows, where the sample row includes variables var0, var1, etc: toffset, var0[0], var0[1], ... var0[N-1], var1[0], var1[1], ... toffset is the number of microseconds into the second to associate with the zeroth value of each variable. N is the sampling rate (#/sec) of all the variables in the sample, rounded up to the next highest integer if the rate is not integral. var0[i] are the vector of values of a variable at time i in the record. The vector may have more then one value, if for example the variable is a histogram.

So a sync record is a 4D ragged array with the following dimensions, where last dimension varies most rapidly:

 syncrec[nsamples][nvars][nSlots][varlen]

nsamples is the number of different sample IDs in the configuration. nvars is the number of variables in a sample. varlen is the number of values for a sample of a variable, usually 1. nSlots is the number of samples per second for a variable/sample, rounded up if necessary. toffset is like an initial variable in the sample with a time and nvalue dimension of 1.

Typical sampling rates are:

rate usec/sample nSlots 1000 1000 1000 100 10000 100 50 20000 50 12.5 80000 13 ARINC (next highest integer) 10 100000 10 8 125000 8 6.25 160000 7 ARINC 3.125 320000 4 ARINC 3 333333 in-exact 3 1.5625 640000 2 ARINC 1 1000000 1

The information to unpack a sync record is stored in the header, which is passed first to clients.

When a sync record is read, the timetags corresponding to the time slot of each variable value are re-constructed from:

sync record sample time, the time at beginning of the second
time offset into the second for each sample, in microseconds
timeIndex of the variable, from 0 to (N-1)

The slot time tags are then: sampleTime = syncTime + toffset + (timeIndex * dt)

If the samples are not actually evenly spaced, then exact time information is lost in resampling into the sync record. Data samples can be discarded, or slots skipped in the output, if a sample time tag is more than NSLOT_LIMIT*dt from the slot time.

For example, assume these timetags for a 10 Hz variable, with some usual timetag jitter:

sample times dataval 00:00:00.09 0 00:00:00.18 1 00:00:00.32 2 00:00:00.60 3 gap, followed by closely spaced samples, typically 00:00:00.62 4 due to DSM latency. 00:00:00.65 5 00:00:00.71 6 00:00:00.79 7 00:00:01.20 8 big gap 0.41 sec 00:00:01.22 9

The corresponding values will be put into a row of a sync record whose time is 00:00:00. The time offset for the sample row will be .09 sec (the offset of the first sample).

Placing this data in the sync record loses time information for all but the first sample. The slot times in the sync record are (syncTime + toffset + N * dT), where N=[0,9], and dT=0.1 sec:

As each sample is received, it is placed in the next slot in the sync record, unless its time tag differs from the slot time by more than NSLOT_LIMIT time dt.

syncrec dataval time difference from actual sample time 00:00:00.09 0 0.0 00:00:00.19 1 +0.1 00:00:00.29 2 -0.3 00:00:00.39 3 -0.21 value from 00:00:00.60 00:00:00.49 4 -0.13 value from 00:00:00.62 00:00:00.59 5 -0.03 value from 00:00:00.65 00:00:00.69 6 -0.2 00:00:00.79 7 0.0 00:00:00.89 NaN result of gap, diff of 0.31 sec 00:00:00.99 8 -0.21 value from 00:00:01.20 00:00:01.10 9 0.0 next record, offset of 0.10 sec

A previous version of SyncRecordSource computed a slot time index for each sample timeIndex = (sampleTime - syncTime - toffset + dt/2) / dt This resulted in an more loss of samples over gaps and latency jitter: 00:00:00.09 0 0.0 00:00:00.19 1 +0.1 00:00:00.29 2 -0.3 00:00:00.39 NaN 00:00:00.49 NaN 00:00:00.59 4 data from 0.62 00:00:00.69 NaN 00:00:00.79 7 data from 0.79 00:00:00.89 NaN 00:00:00.99 NaN 00:00:01.22 NaN

The received samples are sorted in time before they are placed in the sync record, but because a sample from the next second may be placed in the previous sync record, we have maintain two sync records as they are filled.

References _syncRecordDataSampleTag, _syncRecordHeaderSampleTag, _syncTime, addSampleTag(), nidas::core::SampleTag::setDSMId(), nidas::core::SampleTag::setRate(), nidas::core::SampleTag::setSampleId(), nidas::core::SampleTag::setSensorId(), SYNC_RECORD_HEADER_ID, and SYNC_RECORD_ID.

SyncRecordSource::~SyncRecordSource ( )

virtual

References _syncInfo, _syncRecord, nidas::dynld::raf::SyncInfo::discarded, nidas::core::SampleT< DataT >::freeReference(), GET_DSM_ID, GET_SPS_ID, ILOG, nidas::dynld::raf::SyncInfo::noverWritten, nidas::dynld::raf::SyncInfo::rate, nidas::dynld::raf::SyncInfo::skipped, and nidas::dynld::raf::SyncInfo::total.

nidas::dynld::raf::SyncRecordSource::SyncRecordSource ( const SyncRecordSource & )

private

No copying.

Member Function Documentation

void nidas::dynld::raf::SyncRecordSource::addSampleClient	(	SampleClient *	client	)
throw	(
	)

inlinevirtual

Implementation of SampleSource::addSampleClient().

Implements nidas::core::SampleSource.

void nidas::dynld::raf::SyncRecordSource::addSampleClientForTag	(	SampleClient *	client,
		const SampleTag *
	)
throw	(
	)

inlinevirtual

Add a Client for a given SampleTag.

Implementation of SampleSource::addSampleClient().

Implements nidas::core::SampleSource.

void nidas::dynld::raf::SyncRecordSource::addSampleTag	(	const SampleTag *	tag	)
throw	(
	)

inlineprivatevirtual

Add a SampleTag to this SampleSource.

Implements nidas::core::SampleSource.

References nidas::core::SampleSourceSupport::addSampleTag().

Referenced by SyncRecordSource().

int SyncRecordSource::advanceRecord ( dsm_time_t timetag )

private

References _current, _syncInfo, _syncRecord, _syncTime, allocateRecord(), nidas::util::UTime::format(), nextRecordIndex(), and sendSyncRecord().

void SyncRecordSource::allocateRecord	(	int	irec,
		dsm_time_t	timetag
	)

private

References _dataPtr, _recSize, _syncRecord, _syncTime, nidas::util::LogContext::active(), nidas::core::doubleNAN, nidas::util::LogContext::log(), LOG_DEBUG, nidas::core::Sample::setTimeTag(), SYNC_RECORD_ID, and USECS_PER_SEC.

Referenced by advanceRecord(), and nextRecord().

bool SyncRecordSource::checkTime	(	const Sample *	samp,
		SyncInfo &	sinfo,
		SampleTracer &	stracer,
		nidas::util::LogContext &	lc,
		int	warn_times
	)

private

Returns: : true OK, false: cannot place sample in either sync record.

int SyncRecordSource::computeSlotIndex	(	const Sample *	samp,
		SyncInfo &	sinfo
	)

Which time slot should a sample be placed.

References _syncRecord, _syncTime, nidas::dynld::raf::SyncInfo::dtUsec, nidas::dynld::raf::SyncInfo::getRecordIndex(), nidas::core::Sample::getTimeTag(), log(), LOG_ERR, nextRecord(), and USECS_PER_SEC.

Referenced by nidas::dynld::raf::SyncInfo::computeSlotIndex().

void SyncRecordSource::connect	(	SampleSource *	source	)
throw	(
	)

virtual

Connect the resampler to a source.

Implements nidas::core::Resampler.

References DLOG, nidas::dynld::raf::Aircraft::getAircraft(), and nidas::core::Project::getInstance().

Referenced by nidas::dynld::raf::SyncRecordGenerator::connectSource().

void SyncRecordSource::createHeader	(	std::ostream &	)
throw	(
	)

private

Referenced by sendSyncHeader().

void SyncRecordSource::disconnect	(	SampleSource *	source	)
throw	(
	)

virtual

Implements nidas::core::Resampler.

void SyncRecordSource::flush	(	)
throw	(
	)

virtual

Implementation of Resampler::flush().

Send current sync record, whether finished or not.

Implements nidas::core::Resampler.

References _current, DLOG, nextRecordIndex(), NSYNCREC, and sendSyncRecord().

int nidas::dynld::raf::SyncRecordSource::getClientCount	(	)	const
throw	(
	)

inlinevirtual

How many SampleClients are currently in my list.

Implements nidas::core::SampleSource.

SampleSource* nidas::dynld::raf::SyncRecordSource::getProcessedSampleSource ( )

inlinevirtual

Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples.

SampleClients use this method to get a pointer to whatever sample source they are interested in. Derived classes can return NULL if they are not a SampleSource of processed samples.

Implements nidas::core::SampleSource.

SampleSource* nidas::dynld::raf::SyncRecordSource::getRawSampleSource ( )

inlinevirtual

Several objects in NIDAS can be both a SampleSource of raw Samples and processed Samples.

SampleClients use this method to get a pointer to whatever sample source they are interested in. Derived classes can return NULL if they are not a SampleSource of raw samples.

Implements nidas::core::SampleSource.

const SampleStats& nidas::dynld::raf::SyncRecordSource::getSampleStats ( ) const

inlinevirtual

Implements nidas::core::SampleSource.

SampleTagIterator nidas::dynld::raf::SyncRecordSource::getSampleTagIterator ( ) const

inlinevirtual

Implementation of SampleSource::getSampleTagIterator().

Implements nidas::core::SampleSource.

std::list<const SampleTag*> nidas::dynld::raf::SyncRecordSource::getSampleTags ( ) const

inlinevirtual

Get the output SampleTags.

Implements nidas::core::SampleSource.

Referenced by nidas::dynld::raf::SyncRecordGenerator::connectSource().

void SyncRecordSource::init ( )

Create the SyncInfo objects for all samples and their variables that will go in the sync record.

SyncRecordSource first generates the list of variables with selectVariablesFromProject() prior to calling init().

References _halfMaxUsecsPerSample, _initialized, _recSize, _syncInfo, _syncRecordDataSampleTag, _syncRecordHeaderSampleTag, _variables, nidas::core::SampleTag::addVariable(), nidas::dynld::raf::SyncInfo::addVariable(), nidas::core::SampleTag::getId(), nidas::core::SampleTag::getRate(), nidas::core::Variable::getSampleTag(), rate, nidas::dynld::raf::SyncInfo::sampleLength, nidas::dynld::raf::SyncInfo::sampleSRIndex, USECS_PER_SEC, nidas::dynld::raf::SyncInfo::variables, and nidas::dynld::raf::SyncInfo::varSRIndex.

void nidas::dynld::raf::SyncRecordSource::log	(	nidas::util::LogContext &	lc,
		const std::string &	msg,
		const Sample *	samp,
		const SyncInfo &	sinfo
	)

private

Referenced by checkTime(), computeSlotIndex(), and nextRecord().

void nidas::dynld::raf::SyncRecordSource::log	(	nidas::util::LogContext &	lc,
		const std::string &	msg,
		const SyncInfo &	sinfo
	)

private

bool SyncRecordSource::nextRecord ( SyncInfo & sinfo )

If the next sync record is non-null, do sinfo.incrementRecord().

References _current, _syncRecord, _syncTime, allocateRecord(), nidas::dynld::raf::SyncInfo::getRecordIndex(), nidas::dynld::raf::SyncInfo::incrementRecord(), log(), LOG_ERR, nextRecordIndex(), nidas::dynld::raf::SyncInfo::overWritten, and USECS_PER_SEC.

Referenced by computeSlotIndex(), and nidas::dynld::raf::SyncInfo::incrementSlot().

int SyncRecordSource::nextRecordIndex ( int i )

static

Return the index of the next sync record.

References NSYNCREC.

Referenced by advanceRecord(), nidas::dynld::raf::SyncInfo::advanceRecord(), flush(), nextRecord(), and prevRecordIndex().

SyncRecordSource& nidas::dynld::raf::SyncRecordSource::operator= ( const SyncRecordSource & )

private

No assignment.

void SyncRecordSource::preLoadCalibrations	(	dsm_time_t	sampleTime	)
throw	(
	)

References nidas::util::LogContext::active(), nidas::util::endlog(), nidas::core::Polynomial::getCoefficients(), nidas::core::Variable::getConverter(), nidas::core::Linear::getIntercept(), nidas::core::Variable::getName(), nidas::core::Linear::getSlope(), ILOG, LOG_INFO, and nidas::core::VariableConverter::readCalFile().

bool SyncRecordSource::prevRecord ( SyncInfo & sinfo )

If the previous sync record is non-null, do sinfo.decrementRecord().

References _current, _syncRecord, nidas::dynld::raf::SyncInfo::decrementRecord(), nidas::dynld::raf::SyncInfo::getRecordIndex(), and prevRecordIndex().

Referenced by nidas::dynld::raf::SyncInfo::decrementSlot().

int SyncRecordSource::prevRecordIndex ( int i )

static

Return the index of the previous sync record.

Since currently NSYNCREC==2, this return the same value as nextRecordIndex().

References nextRecordIndex().

Referenced by prevRecord().

bool SyncRecordSource::receive	(	const Sample *	s	)
throw	(
	)

virtual

Method called to pass a sample to this client.

This method is typically called by a SampleSource for each of its SampleClients when it has a sample ready. Returns true: success false: sample rejected. This is meant to signal a warning-type situation - like a socket not being available temporarily. True errors will be thrown as an IOException.

Implements nidas::core::SampleClient.

void nidas::dynld::raf::SyncRecordSource::removeSampleClient	(	SampleClient *	c	)
throw	(
	)

inlinevirtual

Remove a SampleClient from this SampleSource.

Implements nidas::core::SampleSource.

Referenced by nidas::dynld::raf::SyncRecordGenerator::~SyncRecordGenerator().

void nidas::dynld::raf::SyncRecordSource::removeSampleClientForTag	(	SampleClient *	c,
		const SampleTag *
	)
throw	(
	)

inlinevirtual

Remove a SampleClient for a given SampleTag from this SampleSource.

The pointer to the SampleClient must remain valid, until after it is removed.

Implements nidas::core::SampleSource.

void nidas::dynld::raf::SyncRecordSource::removeSampleTag	(	const SampleTag *	tag	)
throw	(
	)

inlineprivatevirtual

Implements nidas::core::SampleSource.

void SyncRecordSource::selectVariablesFromProject	(	Project *	project,
		std::list< const Variable * > &	variables
	)

static

This method and selectVariablesFromSensor() are used to select the list of variables from a Project configuration in order of sensor, with variables in order for each sensor, accepting only the variables which make sense for Aircraft SyncRecords.

The variables are appended to the variables list.

Rather than rely on the sample tags from the source, this allows a single function to be shared to accumulate processed sample tags and variables directly from the Project. Applications (like nimbus) can use this to get the same list of Variables as would be retrieved from SyncRecordReader, except they include all the metadata directly from the Project instead of the sync record header.

References nidas::core::Project::getSensorIterator(), nidas::core::SensorIterator::hasNext(), nidas::core::SensorIterator::next(), and selectVariablesFromSensor().

void SyncRecordSource::selectVariablesFromSensor	(	DSMSensor *	sensor,
		std::list< const Variable * > &	variables
	)

static

See selectVariablesFromProject().

References nidas::core::Variable::CONTINUOUS, nidas::core::Variable::COUNTER, GET_DSM_ID, GET_SPS_ID, nidas::core::SampleTag::getId(), nidas::util::Logger::getInstance(), nidas::core::DSMSensor::getSampleTags(), nidas::core::Variable::getType(), nidas::core::SampleTag::getVariables(), nidas::core::SampleTag::isProcessed(), nidas::util::Logger::log(), and LOG_WARNING.

Referenced by selectVariablesFromProject().

void SyncRecordSource::sendSyncHeader	(	)
throw	(
	)

Generate and send a sync record header sample.

The sync record should have been laid out already, but that happens when a source is connected with connect(SampleSource*). Typically sendSyncHeader() should be called after clients are connected with addSampleClient(). The header time tag is the time of the first raw sample read from the input stream, set in the call to preLoadCalibrations(). This is not to be confused with a NIDAS stream header, like would be generated by a HeaderSource, thus the distinction in the name.

References _headerStream, _source, _syncHeaderTime, createHeader(), nidas::core::SampleSourceSupport::distribute(), DLOG, nidas::core::SampleT< DataT >::getDataPtr(), nidas::core::Sample::getTimeTag(), nidas::core::Sample::setId(), nidas::core::Sample::setTimeTag(), and SYNC_RECORD_HEADER_ID.

void SyncRecordSource::sendSyncRecord ( )

private

References _current, _source, _syncRecord, _syncTime, nidas::util::LogContext::active(), nidas::core::SampleSourceSupport::distribute(), format_time(), nidas::core::Sample::getTimeTag(), nidas::util::LogContext::log(), LOG_DEBUG, and NSYNCREC.

Referenced by advanceRecord(), and flush().

void SyncRecordSource::slog	(	SampleTracer &	stracer,
		const std::string &	msg,
		const Sample *	samp,
		const SyncInfo &	sinfo
	)

private

References _current, _syncTime, nidas::core::SampleTracer::active(), nidas::util::endlog(), format_time(), nidas::dynld::raf::SyncInfo::getRecordIndex(), nidas::dynld::raf::SyncInfo::getSlotIndex(), nidas::dynld::raf::SyncInfo::minDiff, nidas::core::SampleTracer::msg(), nidas::dynld::raf::SyncInfo::nSlots, nidas::dynld::raf::SyncInfo::rate, nidas::dynld::raf::SyncInfo::skipMod, nidas::dynld::raf::SyncInfo::skipModCount, and USECS_PER_SEC.

Referenced by checkTime().

Member Data Documentation

const Aircraft* nidas::dynld::raf::SyncRecordSource::_aircraft

private

unsigned int nidas::dynld::raf::SyncRecordSource::_badLaterSamples

private

int nidas::dynld::raf::SyncRecordSource::_current

private

Index of current sync record.

Referenced by advanceRecord(), flush(), nextRecord(), prevRecord(), sendSyncRecord(), and slog().

double* nidas::dynld::raf::SyncRecordSource::_dataPtr[2]

private

Referenced by allocateRecord().

int nidas::dynld::raf::SyncRecordSource::_halfMaxUsecsPerSample

private

Referenced by init().

std::ostringstream nidas::dynld::raf::SyncRecordSource::_headerStream

private

Referenced by sendSyncHeader().

bool nidas::dynld::raf::SyncRecordSource::_initialized

private

Referenced by init().

size_t nidas::dynld::raf::SyncRecordSource::_recSize

private

Referenced by allocateRecord(), and init().

SampleSourceSupport nidas::dynld::raf::SyncRecordSource::_source

private

Referenced by sendSyncHeader(), and sendSyncRecord().

dsm_time_t nidas::dynld::raf::SyncRecordSource::_syncHeaderTime

private

Referenced by sendSyncHeader().

std::map<dsm_sample_id_t, SyncInfo> nidas::dynld::raf::SyncRecordSource::_syncInfo

private

Info kept for each sample in order to assemble and write sync records.

Note there is not a default, no-arg constuctor for SyncInfo. So you can't do: SyncInfo& sinfo = _syncInfo[id]; which would need the no-arg constructor if the element is not found. Instead, do: map<dsm_sample_id_t, SyncInfo>::iterator si = _syncInfo.find(id); if (si != _syncInfo.end()) { SyncInfo& sinfo = si->second; // use reference to avoid copy ... }

Referenced by advanceRecord(), init(), and ~SyncRecordSource().

SampleT<double>* nidas::dynld::raf::SyncRecordSource::_syncRecord[2]

private

Referenced by advanceRecord(), allocateRecord(), computeSlotIndex(), nextRecord(), prevRecord(), sendSyncRecord(), and ~SyncRecordSource().