wikivis.data.WikiVisDataService Class Reference

Service class for all page revision data related actions. More...

Public Member Functions
void	initialize (ServletContext servContext)
	initializes the data service.
boolean	isKnownPage (String pageTitle)
	determines if a page with the given title is known (and data exists) or not
WikiVisData	getData (ServletContext servContext, String pageTitle, int width, int height, int fromMonth, int fromYear, int toMonth, int toYear) throws RevisionExtractionException
	calculate and returns the data for the given page title and conditions.
WikiVisData	getData (ServletContext servContext, String pageTitle, int width, int height, int fromMonth, int fromYear, int toMonth, int toYear, boolean ignoreChacedData) throws RevisionExtractionException
	calculate and returns the data for the given page title and conditions.
Map	getKnownPages ()
	returns the map of known pages
String	getVersion ()
	returns the version of the service

Private Member Functions
void	computeVariance (WikiVisData data, int fromMonth, int fromYear, int toMonth, int toYear)
	computes and sets the variance values for each author
void	calculateOverallStatistics (WikiVisData data)
	calculates and sets the statistics for the given data
WikiVisData	extractRevisionData (ServletContext servContext, String pageTitle) throws RevisionExtractionException
	loads the revision data from the page data file
void	calculatePositions (WikiVisData data, int width, int height)
	calculates the positions of the nodes of the revision network of the given data.
void	cacheData (WikiVisData data)
	updates the cache with the given data
void	manageCache ()
	tries to optimize the cache with a simple cache strategy
WikiVisData	getCachedData (String pageTitle)
	restores the cahce page data with the given title
String	getDataFileName (String pageTitle)
	returns the file name for the given page title.

Static Private Member Functions
static long	getMonthIndex (int year, int month)
	calculate the month index for the given month and year.
static List< Revision >	filterRevisionList (List< Revision > revisions, int fromMonth, int fromYear, int toMonth, int toYear)
	filters a given revision list according to the filter conditions.
static void	createNodesAndEdges (WikiVisData data, int fromMonth, int fromYear, int toMonth, int toYear)
	creates and sets the revision network from the given data (the data must contain revisions and authors).

Private Attributes
Properties	pageConfig
	the page configuration as Properties instance
Map< String, WikiVisCachedData >	cachedData = new HashMap<String, WikiVisCachedData>()
	the cached data map

Static Private Attributes
static final String	DATA_DIR = "/data/"
	the data directory that holds all page data
static final String	CONFIG_PAGEDATA_FILENAME = "/pagedata-config.xml"
	the configuration file name
static final int	MAX_CACHE_DATA = 10
	the maximum number of cached items
static final int	THRESHOLD_VAR = 50
	the revision number threshold used in variance calculation
static final int	MAX_ALLOWED_NODES = 7000
	the maximum number of authors where eigenvalue calculation is possible (limited to prevent OutOfMemoryError)

Detailed Description

Service class for all page revision data related actions.

Data is loaded from WebContent/data/,the page title to xml file mapping is specified in the configuration file. The configuration file "pagedata-config.xml" is an properties-xml file that contains all page entries with their titles as keys and the xml file name as value.

See Also

java.uitl.Properties

Author

Manuel Wyss e0106.nosp@m.157@.nosp@m.stude.nosp@m.nt.t.nosp@m.uwien.nosp@m..ac..nosp@m.at

Florian Zoubek zoube.nosp@m.k@bi.nosp@m.tanda.nosp@m.rt.a.nosp@m.t

Member Function Documentation

void wikivis.data.WikiVisDataService.cacheData ( WikiVisData  data )

private

updates the cache with the given data

Parameters

data	the data to cache

void wikivis.data.WikiVisDataService.calculateOverallStatistics ( WikiVisData  data )

private

calculates and sets the statistics for the given data

Parameters

data	the data to operate upon

void wikivis.data.WikiVisDataService.calculatePositions ( WikiVisData  data, int  width, int  height  )

private

calculates the positions of the nodes of the revision network of the given data.

If the number of nodes exceeds MAX_ALLOWED_NODES , the positions will not be calculated and the according flag will be set in the data. This limit exists to prevent OutOfMemoryErrors due to eigenvalue calculation of huge adjacency matrices.

Parameters

data	the data to operate upon
width	the width of the visualization area
height	the height of the visualization area

void wikivis.data.WikiVisDataService.computeVariance ( WikiVisData  data, int  fromMonth, int  fromYear, int  toMonth, int  toYear  )

private

computes and sets the variance values for each author

Parameters

data	the data to operate upon
fromMonth	the from month value of the time range filter (0-11)
fromYear	the from year value of the time range filter
toMonth	the to month value of the time range filter (0-11)
toYear	the to year value of the time range filter

static void wikivis.data.WikiVisDataService.createNodesAndEdges ( WikiVisData  data, int  fromMonth, int  fromYear, int  toMonth, int  toYear  )

staticprivate

creates and sets the revision network from the given data (the data must contain revisions and authors).

Filtering of the data will not be performed if any of the given conditions is negative.

Parameters

data	the data operate upon
fromMonth	the month value of the first month to include
fromYear	the year value of the first month to include
toMonth	the month value of the last month to include
toYear	the year value of the last month to include

WikiVisData wikivis.data.WikiVisDataService.extractRevisionData ( ServletContext  servContext, String  pageTitle  ) throws RevisionExtractionException

private

loads the revision data from the page data file

Parameters

servContext	the current servlet context
pageTitle	the page title of the page to load

Returns

the extracted data

Exceptions

RevisionExtractionException

if the revision data could not be loaded

static List<Revision> wikivis.data.WikiVisDataService.filterRevisionList ( List< Revision >  revisions, int  fromMonth, int  fromYear, int  toMonth, int  toYear  )

staticprivate

filters a given revision list according to the filter conditions.

If any condition is negative no filtering will be performed and the given instance will be returned.

Parameters

revisions	a list of revisions to filter
fromMonth	the month value of the first month to include
fromYear	the year value of the first month to include
toMonth	the month value of the last month to include
toYear	the year value of the last month to include

Returns

a filtered list of revisions

WikiVisData wikivis.data.WikiVisDataService.getCachedData ( String  pageTitle )

private

restores the cahce page data with the given title

Parameters

pageTitle

the page title

Returns

the restored data (does not contain variances and revision network)

WikiVisData wikivis.data.WikiVisDataService.getData	(	ServletContext	servContext,
		String	pageTitle,
		int	width,
		int	height,
		int	fromMonth,
		int	fromYear,
		int	toMonth,
		int	toYear
	)		throws RevisionExtractionException

calculate and returns the data for the given page title and conditions.

If any of fromMonth, fromYear, toMonth or toYear, is given a negative value, no filtering will be performed. No caching will be performed.

Parameters

servContext	the current servlet context
pageTitle	the page title
width	the width of the visualization area
height	the height of the visualization area
fromMonth	the from month value of the time range filter (0-11)
fromYear	the from year value of the time range filter
toMonth	the to month value of the time range filter (0-11)
toYear	the to year value of the time range filter

Returns

the requested data

Exceptions

RevisionExtractionException

if the revision data could not be loaded

WikiVisData wikivis.data.WikiVisDataService.getData	(	ServletContext	servContext,
		String	pageTitle,
		int	width,
		int	height,
		int	fromMonth,
		int	fromYear,
		int	toMonth,
		int	toYear,
		boolean	ignoreChacedData
	)		throws RevisionExtractionException

calculate and returns the data for the given page title and conditions.

If any of fromMonth, fromYear, toMonth or toYear, is given a negative value, no filtering will be performed. Caching will be performed if specified.

Parameters

servContext	the current servlet context
pageTitle	the page title
width	the width of the visualization area
height	the height of the visualization area
fromMonth	the from month value of the time range filter (0-11)
fromYear	the from year value of the time range filter
toMonth	the to month value of the time range filter (0-11)
toYear	the to year value of the time range filter
ignoreChacedData	true if no caching should be performed, false otherwise

Returns

the requested data

Exceptions

RevisionExtractionException

if the revision data could not be loaded

String wikivis.data.WikiVisDataService.getDataFileName ( String  pageTitle )

private

returns the file name for the given page title.

The page must be known to the service.

Parameters

pageTitle

the title of the page

Returns

the file containing the revision data

Map wikivis.data.WikiVisDataService.getKnownPages

(

)

returns the map of known pages

Returns

the map of known pages

static long wikivis.data.WikiVisDataService.getMonthIndex ( int  year, int  month  )

staticprivate

calculate the month index for the given month and year.

The characteristics of this index are:

• if month1/year1 is before month2/year2 then monthIndex1 < monthIndex2
• if month1/year1 is equal month2/year2 then monthIndex1 = monthIndex2
• if month1/year1 is after month2/year2 then monthIndex1 > monthIndex2

Parameters

year	the year
month	the month (0-11)

Returns

String wikivis.data.WikiVisDataService.getVersion

(

)

returns the version of the service

Returns

the version of the service

void wikivis.data.WikiVisDataService.initialize

(

ServletContext

servContext

)

initializes the data service.

This method must be called and succeed before any other method of this class should be called

Parameters

servContext

the Servlet context used in this service

boolean wikivis.data.WikiVisDataService.isKnownPage

(

String

pageTitle

)

determines if a page with the given title is known (and data exists) or not

Parameters

pageTitle

the page title of the page

Returns

true if the page is known, false otherwise

void wikivis.data.WikiVisDataService.manageCache ( )

private

tries to optimize the cache with a simple cache strategy

Member Data Documentation

Map<String, WikiVisCachedData> wikivis.data.WikiVisDataService.cachedData = new HashMap<String, WikiVisCachedData>()

private

the cached data map

final String wikivis.data.WikiVisDataService.CONFIG_PAGEDATA_FILENAME = "/pagedata-config.xml"

staticprivate

the configuration file name

final String wikivis.data.WikiVisDataService.DATA_DIR = "/data/"

staticprivate

the data directory that holds all page data

final int wikivis.data.WikiVisDataService.MAX_ALLOWED_NODES = 7000

staticprivate

the maximum number of authors where eigenvalue calculation is possible (limited to prevent OutOfMemoryError)

final int wikivis.data.WikiVisDataService.MAX_CACHE_DATA = 10

staticprivate

the maximum number of cached items

Properties wikivis.data.WikiVisDataService.pageConfig

private

the page configuration as Properties instance

final int wikivis.data.WikiVisDataService.THRESHOLD_VAR = 50

staticprivate

the revision number threshold used in variance calculation

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

• src/wikivis/data/WikiVisDataService.java