Package org.aksw.limes.core.io.cache

Class MemoryCache

java.lang.Object

org.aksw.limes.core.io.cache.ACache

org.aksw.limes.core.io.cache.MemoryCache

All Implemented Interfaces:

ICache

Direct Known Subclasses:

HybridCache

public class MemoryCache
extends ACache

Implements a cache that is exclusively in memory. Fastest cache as it does not need to read from the hard drive.

Version:

Jul 8, 2015

Author:

Axel-C. Ngonga Ngomo (ngonga@informatik.uni-leipzig.de), Klaus Lyko, Mohamed Sherif (sherif@informatik.uni-leipzig.de)

Field Summary

Fields

Modifier and Type	Field	Description
protected Iterator<Instance>	instanceIterator
protected HashMap<String,Instance>	instanceMap

Constructor Summary

Constructors

Constructor	Description
MemoryCache()

Method Summary

Modifier and Type	Method	Description
void	addInstance(Instance i)
ACache	addProperty(String sourcePropertyName, String targetPropertyName, String processingChain)	Method to process data of a property into a new property with specific preprocessing.
void	addTriple(String s, String p, String o)	Adds a new spo statement to the cache
MemoryCache	clone()	Ignores instanceIterator since there is no sane way to test the equality of iterators
boolean	containsInstance(Instance i)
boolean	containsUri(String uri)
boolean	equals(Object obj)
ArrayList<Instance>	getAllInstances()	Returns all the instance contained in the cache
Set<String>	getAllProperties()	Returns a set of properties (most likely) all instances have.
ArrayList<String>	getAllUris()
Instance	getInstance(String uri)
Instance	getNextInstance()	Returns the next instance in the list of instances
ACache	getSample(int size)
int	hashCode()
org.apache.jena.rdf.model.Model	parseCSVtoRDFModel(String baseURI, String IDbaseURI, String rdfType)	Basic method to create a JENA Model out of a cache.
void	replaceInstance(String uri, Instance a)
void	resetIterator()
int	size()
String	toString()

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

instanceMap

protected HashMap<String,Instance> instanceMap

instanceIterator

protected Iterator<Instance> instanceIterator

Constructor Detail

MemoryCache

public MemoryCache()

Method Detail

getNextInstance

public Instance getNextInstance()

Returns the next instance in the list of instances

Specified by:

getNextInstance in class ACache

Returns:

null if no next instance, else the next instance

getAllInstances

public ArrayList<Instance> getAllInstances()

Returns all the instance contained in the cache

Specified by:

getAllInstances in class ACache

Returns:

ArrayList containing all instances

addInstance

public void addInstance(Instance i)

Specified by:

addInstance in class ACache

getInstance

public Instance getInstance(String uri)

Specified by:

getInstance in class ACache

Parameters:

uri - URI to look for

Returns:

The instance with the URI uri if it is in the cache, else null

size

public int size()

Specified by:

size in class ACache

Returns:

The size of the cache

addTriple

public void addTriple(String s,
                      String p,
                      String o)

Adds a new spo statement to the cache

Specified by:

addTriple in class ACache

Parameters:

s - The URI of the instance linked to o via p

p - The property which links s and o

o - The value of the property of p for the entity s

containsInstance

public boolean containsInstance(Instance i)

Specified by:

containsInstance in class ACache

Parameters:

i - The instance to look for

Returns:

true if the URI of the instance is found in the cache

containsUri

public boolean containsUri(String uri)

Specified by:

containsUri in class ACache

Parameters:

uri - The URI to looks for

Returns:

True if an instance with the URI uri is found in the cache, else false

resetIterator

public void resetIterator()

Specified by:

resetIterator in class ACache

toString

public String toString()

Overrides:

toString in class Object

getAllUris

public ArrayList<String> getAllUris()

Specified by:

getAllUris in class ACache

getSample

public ACache getSample(int size)

Specified by:

getSample in class ACache

addProperty

public ACache addProperty(String sourcePropertyName,
                          String targetPropertyName,
                          String processingChain)

Description copied from class: ACache

Method to process data of a property into a new property with specific preprocessing.

Specified by:

addProperty in class ACache

Parameters:

sourcePropertyName - Name of the property to process.

targetPropertyName - Name of the new property to process data into.

processingChain - Preprocessing Expression.

Returns:

Cache after property add

getAllProperties

public Set<String> getAllProperties()

Returns a set of properties (most likely) all instances have.

Specified by:

getAllProperties in class ACache

Returns:

set of all properties

replaceInstance

public void replaceInstance(String uri,
                            Instance a)

Specified by:

replaceInstance in class ACache

parseCSVtoRDFModel

public org.apache.jena.rdf.model.Model parseCSVtoRDFModel(String baseURI,
                                                          String IDbaseURI,
                                                          String rdfType)

Description copied from class: ACache

Basic method to create a JENA Model out of a cache. Restriction 1: Assumes all objects are literal values. Thus, resource URIs are represented as Strings. Restriction 2: Adds a rdf:Type statement for all instances.

Specified by:

parseCSVtoRDFModel in class ACache

Parameters:

baseURI - Base URI of properties, could be empty.

IDbaseURI - Base URI for id of resources: URI(instance) := IDbaseURI+instance.getID(). Could be empty.

rdfType - rdf:Type of the instances.

Returns:

JENA RDF Model

clone

public MemoryCache clone()

Ignores instanceIterator since there is no sane way to test the equality of iterators

Specified by:

clone in class ACache

hashCode

public int hashCode()

Specified by:

hashCode in class ACache

equals

public boolean equals(Object obj)

Specified by:

equals in class ACache