org.apache.jena.riot.system

Class FastAbbreviatingPrefixMap

java.lang.Object

org.apache.jena.riot.system.PrefixMapBase

org.apache.jena.riot.system.FastAbbreviatingPrefixMap

All Implemented Interfaces:

PrefixMap

public class FastAbbreviatingPrefixMap
extends PrefixMapBase

A prefix map implementation suited to output heavy workloads

This is an alternative implementation of the PrefixMap interface, it is broadly similar to the default PrefixMapStd implementation but is faster in output heavy workloads. If you are calling the PrefixMap.expand(String) or PrefixMap.expand(String, String) methods a lot then you should be using this implementation.

To improve on output performance this implementation maintains a Trie mapping namespace IRIs to their prefixes as well as a normal mapping. Therefore IRI abbreviation can be done as an approximately O(1) operation in the worst case . If you contrast this with the abbreviation performance of the default PrefixMap which is worst case O(n) then this is a substantial saving in scenarios where you primarily use a prefix map for output.

Generally speaking all other operations should be roughly equivalent to the default PrefixMap though the memory overhead of this implementation will be marginally higher due to the extra information maintained in the Trie.

Constructor Summary

Constructors

Constructor and Description
FastAbbreviatingPrefixMap() Create a new fast abbreviating prefix map
FastAbbreviatingPrefixMap(PrefixMap pmap) Create a new fast abbreviating prefix map which copies mappings from an existing map

Method Summary

Methods

Modifier and Type	Method and Description
Pair<String,String>	abbrev(String uriStr) Abbreviate an IRI and return a pair of prefix and local parts, or null.
String	abbreviate(String uriStr) Abbreviate an IRI or return null
void	add(String prefix, org.apache.jena.iri.IRI iri) Add a prefix, overwrites any existing association
boolean	contains(String prefix) Gets whether the map contains a given prefix
void	delete(String prefix) Delete a prefix
String	expand(String prefixedName) Expand a prefix named, return null if it can't be expanded
String	expand(String prefix, String localName) Expand a prefix, return null if it can't be expanded
Map<String,org.apache.jena.iri.IRI>	getMapping() Return the underlying mapping, this is generally unsafe to modify and implementations may opt to return an unmodifiable view of the mapping if they wish
boolean	isEmpty() return whether the
int	size() Return the number of entries in the prefix map.

Methods inherited from class org.apache.jena.riot.system.PrefixMapBase

add, getMappingCopy, getMappingCopyStr, putAll, putAll, putAll, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FastAbbreviatingPrefixMap

public FastAbbreviatingPrefixMap()

Create a new fast abbreviating prefix map

FastAbbreviatingPrefixMap

public FastAbbreviatingPrefixMap(PrefixMap pmap)

Create a new fast abbreviating prefix map which copies mappings from an existing map

Parameters:

pmap - Prefix Map

Method Detail

getMapping

public Map<String,org.apache.jena.iri.IRI> getMapping()

Description copied from interface: PrefixMap

Return the underlying mapping, this is generally unsafe to modify and implementations may opt to return an unmodifiable view of the mapping if they wish

Returns:

Underlying mapping

add

public void add(String prefix,
       org.apache.jena.iri.IRI iri)

Description copied from interface: PrefixMap

Add a prefix, overwrites any existing association

Parameters:

prefix - Prefix

iri - Namespace IRI

delete

public void delete(String prefix)

Description copied from interface: PrefixMap

Delete a prefix

Parameters:

prefix - Prefix to delete

contains

public boolean contains(String prefix)

Description copied from interface: PrefixMap

Gets whether the map contains a given prefix

Parameters:

prefix - Prefix

Returns:

True if the prefix is contained in the map, false otherwise

abbreviate

public String abbreviate(String uriStr)

Description copied from interface: PrefixMap

Abbreviate an IRI or return null

Parameters:

uriStr - URI to abbreviate

Returns:

URI in prefixed name form if possible, null otherwise

abbrev

public Pair<String,String> abbrev(String uriStr)

Description copied from interface: PrefixMap

Abbreviate an IRI and return a pair of prefix and local parts, or null.

Parameters:

uriStr - URI string to abbreviate

Returns:

Pair of prefix and local name

See Also:

PrefixMap.abbreviate(java.lang.String)

expand

public String expand(String prefixedName)

Description copied from interface: PrefixMap

Expand a prefix named, return null if it can't be expanded

Specified by:

expand in interface PrefixMap

Overrides:

expand in class PrefixMapBase

Parameters:

prefixedName - Prefixed Name

Returns:

Expanded URI if possible, null otherwise

expand

public String expand(String prefix,
            String localName)

Description copied from interface: PrefixMap

Expand a prefix, return null if it can't be expanded

Parameters:

prefix - Prefix

localName - Local name

Returns:

Expanded URI if possible, null otherwise

isEmpty

public boolean isEmpty()

Description copied from interface: PrefixMap

return whether the

Returns:

boolean

size

public int size()

Description copied from interface: PrefixMap

Return the number of entries in the prefix map.

Returns:

Size of the prefix mapping