org.exist.indexing.impl
Class NGramIndexWorker

java.lang.Object
  org.exist.indexing.impl.NGramIndexWorker

All Implemented Interfaces:

IndexWorker

public class NGramIndexWorker
extends Object
implements IndexWorker

Each index entry maps a key (collectionId, ngram) to a list of occurrences, which has the following structure:

[docId : int, nameType: byte, occurrenceCount: int, entrySize: long, [id: NodeId, offset: int, ...]* ]

Nested Class Summary

class

NGramIndexWorker.NGramMatch

Constructor Summary

NGramIndexWorker(NGramIndex index)

Method Summary

Object	configure(IndexController controller, NodeList configNodes, Map namespaces) Read an index configuration from an collection.xconf configuration document.
void	flush() Flush the index.
String[]	getDistinctNGrams(CharSequence text)
Index	getIndex()
String	getIndexId() Returns an ID which uniquely identifies this index.
String	getIndexName() Returns an name which uniquely identifies this index.
StreamListener	getListener(int mode, DocumentImpl document) Return a stream listener to index the specified document in the specified mode.
MatchListener	getMatchListener(NodeProxy proxy) Returns a MatchListener, which can be used to filter (and manipulate) the XML output generated by the serializer when serializing query results.
int	getN()
StoredNode	getReindexRoot(StoredNode node, NodePath path, boolean includeSelf) When adding or removing nodes to or from the document tree, it might become necessary to reindex some parts of the tree, in particular if indexes are defined on mixed content nodes.
void	removeCollection(Collection collection) Remove all indexes for the given collection, its subcollections and all resources..
Occurrences[]	scanIndex(DocumentSet docs)
NodeSet	search(int contextId, DocumentSet docs, List qnames, String ngram, XQueryContext context, NodeSet contextSet, int axis)
void	setDocument(DocumentImpl document, int newMode) Notify this worker to operate on the specified document, using the mode given.
String[]	tokenize(CharSequence text)

Methods inherited from class java.lang.Object

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

Constructor Detail

NGramIndexWorker

public NGramIndexWorker(NGramIndex index)

Method Detail

getIndexId

public String getIndexId()

Description copied from interface: IndexWorker

Returns an ID which uniquely identifies this index. This will usually be the class name.

Specified by:

getIndexId in interface IndexWorker

Returns:

a unique ID identifying this index.

getIndexName

public String getIndexName()

Description copied from interface: IndexWorker

Returns an name which uniquely identifies this index.

Specified by:

getIndexName in interface IndexWorker

Returns:

a unique name identifying this index.

getIndex

public Index getIndex()

getN

public int getN()

configure

public Object configure(IndexController controller,
                        NodeList configNodes,
                        Map namespaces)
                 throws DatabaseConfigurationException

Description copied from interface: IndexWorker

Read an index configuration from an collection.xconf configuration document. This method is called by the CollectionConfiguration while reading the collection.xconf configuration file for a given collection. The configNodes parameter lists all top-level child nodes below the <index> element in the collection.xconf. The IndexWorker should scan this list and handle those elements it understands. The returned Object will be stored in the collection configuration structure associated with each collection. It can later be retrieved from the collection configuration, e.g. to check if a given node should be indexed or not.

Specified by:

configure in interface IndexWorker

configNodes - lists the top-level child nodes below the <index> element in collection.xconf

namespaces - the active prefix/namespace map

Returns:

an arbitrary configuration object to be kept for this index in the collection configuration

Throws:

DatabaseConfigurationException - if a configuration error occurs

flush

public void flush()

Description copied from interface: IndexWorker

Flush the index. This method will be called when indexing a document. The implementation should immediately process all data it has buffered (if there is any), release as many memory resources as it can and prepare for being reused for a different job.

Specified by:

flush in interface IndexWorker

removeCollection

public void removeCollection(Collection collection)

Description copied from interface: IndexWorker

Remove all indexes for the given collection, its subcollections and all resources..

Specified by:

removeCollection in interface IndexWorker

search

public NodeSet search(int contextId,
                      DocumentSet docs,
                      List qnames,
                      String ngram,
                      XQueryContext context,
                      NodeSet contextSet,
                      int axis)
               throws TerminatedException

Throws:

TerminatedException

scanIndex

public Occurrences[] scanIndex(DocumentSet docs)

Specified by:

scanIndex in interface IndexWorker

getListener

public StreamListener getListener(int mode,
                                  DocumentImpl document)

Description copied from interface: IndexWorker

Return a stream listener to index the specified document in the specified mode. There will never be more than one StreamListener being used per thread, so it is safe for the implementation to reuse a single StreamListener. Parameter mode specifies the type of the current operation.

Specified by:

getListener in interface IndexWorker

Parameters:

mode - one of StreamListener.STORE, StreamListener.REMOVE_NODES or StreamListener.REMOVE_ALL_NODES.

document - the document to be indexed.

Returns:

a StreamListener

getMatchListener

public MatchListener getMatchListener(NodeProxy proxy)

Description copied from interface: IndexWorker

Returns a MatchListener, which can be used to filter (and manipulate) the XML output generated by the serializer when serializing query results. The method should return null if the implementation is not interested in receiving serialization events.

Specified by:

getMatchListener in interface IndexWorker

Parameters:

proxy - the NodeProxy which is being serialized

Returns:

a MatchListener or null if the implementation does not want to receive serialization events

getReindexRoot

public StoredNode getReindexRoot(StoredNode node,
                                 NodePath path,
                                 boolean includeSelf)

Description copied from interface: IndexWorker

When adding or removing nodes to or from the document tree, it might become necessary to reindex some parts of the tree, in particular if indexes are defined on mixed content nodes. This method will call IndexWorker.getReindexRoot(org.exist.dom.StoredNode, org.exist.storage.NodePath, boolean) on each configured index. It will then return the top-most root.

Specified by:

getReindexRoot in interface IndexWorker

Parameters:

node - the node to be modified.

path - path the NodePath of the node

includeSelf - if set to true, the current node itself will be included in the check

Returns:

the top-most root node to be reindexed

tokenize

public String[] tokenize(CharSequence text)

getDistinctNGrams

public String[] getDistinctNGrams(CharSequence text)

setDocument

public void setDocument(DocumentImpl document,
                        int newMode)

Description copied from interface: IndexWorker

Notify this worker to operate on the specified document, using the mode given. mode will be one of StreamListener.STORE, StreamListener.REMOVE_NODES or StreamListener.REMOVE_ALL_NODES.

Specified by:

setDocument in interface IndexWorker

Parameters:

document - the document which is processed

newMode - the current operation mode