DataLoad Class Reference

A class used in the North service to load data from the buffer. More...

#include <data_load.h>

Inheritance diagram for DataLoad:

Collaboration diagram for DataLoad:

Public Member Functions
	DataLoad (const std::string &name, long streamId, StorageClient *storage)
	DataLoad Constructor. More...
virtual	~DataLoad ()
	DataLoad destructor. More...
void	loadThread ()
	The background thread that loads data from the database.
bool	setDataSource (const std::string &source)
	Set the source of data for the service. More...
void	triggerRead (unsigned int blockSize)
	Trigger the loading thread to read a block of data. More...
void	updateLastSentId (unsigned long id)
	Update the last sent ID for our stream.
void	flushLastSentId ()
	Flush the last sent Id to the storeage layer.
ReadingSet *	fetchReadings (bool wait)
	Fetch Readings. More...
void	shutdown ()
	External call to shutdown the north service.
void	restart ()
	External call to restart the north service.
bool	isRunning ()
void	configChange (const std::string &category, const std::string &newConfig)
	Configuration change for one of the filters or to the pipeline. More...
void	configChildCreate (const std::string &, const std::string &, const std::string &)
void	configChildDelete (const std::string &, const std::string &)
unsigned long	getLastFetched ()
void	setBlockSize (unsigned long blockSize)
void	setStreamUpdate (unsigned long streamUpdate)
void	setPerfMonitor (PerformanceMonitor *perfMonitor)
const std::string &	getName ()
StorageClient *	getStorage ()
void	setPrefetchLimit (unsigned int limit)
Public Member Functions inherited from ServiceHandler
virtual bool	securityChange (const std::string &payload)

Static Public Member Functions
static void	passToOnwardFilter (OUTPUT_HANDLE *outHandle, READINGSET *readings)
	Pass the current readings set to the next filter in the pipeline. More...
static void	pipelineEnd (OUTPUT_HANDLE *outHandle, READINGSET *readings)
	Use the current readings (they have been filtered by all filters) More...

Detailed Description

A class used in the North service to load data from the buffer.

This class is responsible for loading the reading from the storage service and buffering them ready for the egress thread to process them.

Constructor & Destructor Documentation

DataLoad()

DataLoad::DataLoad	(	const std::string &	name,
		long	streamId,
		StorageClient *	storage
	)

DataLoad Constructor.

Create and start the loading thread

~DataLoad()

DataLoad::~DataLoad ( )

virtual

DataLoad destructor.

Shutdown and wait for the loading thread

Member Function Documentation

configChange()

void DataLoad::configChange ( const std::string &  category, const std::string &  newConfig  )

virtual

Configuration change for one of the filters or to the pipeline.

Parameters

category	The name of the configuration category
newConfig	The new category contents

The category that has changed is the one for the north service itself. The only items that concerns us here is the filter item that defines the filter pipeline and the data source. If the item is the filter pipeline we extract that item and check to see if it defines a pipeline that is different to the one we currently have.

If it is the filter pipeline we destroy the current pipeline and create a new one.

Implements ServiceHandler.

fetchReadings()

ReadingSet * DataLoad::fetchReadings

(

bool

wait

)

Fetch Readings.

Parameters

wait	Boolean to determine if the call should block the calling thread

Returns

ReadingSet* Return a block of readings from the buffer

passToOnwardFilter()

void DataLoad::passToOnwardFilter ( OUTPUT_HANDLE *  outHandle, READINGSET *  readingSet  )

static

Pass the current readings set to the next filter in the pipeline.

Note: This routine must be passed to all filters "plugin_init" except the last one

Static method

Parameters

outHandle	Pointer to next filter
readings	Current readings set

pipelineEnd()

void DataLoad::pipelineEnd ( OUTPUT_HANDLE *  outHandle, READINGSET *  readingSet  )

static

Use the current readings (they have been filtered by all filters)

The assumption is that one of two things has happened.

1. The filtering has all been done in place. In which case the m_data vector is in the ReadingSet passed in here.
2. The filtering has created new ReadingSet in which case the reading vector must be copied into m_data from the ReadingSet.

Note: This routine must be passed to last filter "plugin_init" only

Static method

Parameters

outHandle	Pointer to DataLoad class
readingSet	Filtered reading set being added to Ingest::m_data

setDataSource()

bool DataLoad::setDataSource

(

const std::string &

source

)

Set the source of data for the service.

Parameters

source

The data source

triggerRead()

void DataLoad::triggerRead

(

unsigned int

blockSize

)

Trigger the loading thread to read a block of data.

This is called by any thread to request that data be added to the buffer ready for collection.

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

• C/services/north/include/data_load.h
• C/services/north/data_load.cpp