FastAbbreviatingPrefixMap (Apache Jena ARQ)

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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
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
`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
`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