Soprano  2.7.56
Public Member Functions | Static Public Member Functions
Soprano::Index::IndexFilterModel Class Reference

The IndexFilterModel provides a full text index around any Soprano Model. More...

#include <Soprano/Index/IndexFilterModel>

+ Inheritance diagram for Soprano::Index::IndexFilterModel:

List of all members.

Public Member Functions

 IndexFilterModel (const QString &indexDir, Soprano::Model *model=0)
 IndexFilterModel (CLuceneIndex *index, Soprano::Model *model=0)
 ~IndexFilterModel ()
CLuceneIndexindex () const
Soprano::Error::ErrorCode addStatement (const Soprano::Statement &statement)
Soprano::Error::ErrorCode removeStatement (const Soprano::Statement &statement)
Soprano::Error::ErrorCode removeAllStatements (const Soprano::Statement &statement)
QueryResultIterator executeQuery (const QString &query, Query::QueryLanguage language, const QString &userQueryLanguage=QString()) const
void setTransactionCacheSize (int size)
int transactionCacheSize () const
void rebuildIndex ()
void optimizeIndex ()
void addIndexOnlyPredicate (const QUrl &predicate)
void setIndexOnlyPredicates (const QList< QUrl > &predicates)
QList< QUrlindexOnlyPredicates () const
void addForceIndexPredicate (const QUrl &predicate)
void setForceIndexPredicates (const QList< QUrl > &predicates)
QList< QUrlforceIndexPredicates () const

Static Public Member Functions

static QString encodeStringForLuceneQuery (const QString &value)
static QString encodeUriForLuceneQuery (const QUrl &uri)

Detailed Description

The IndexFilterModel provides a full text index around any Soprano Model.

All statements with a literal object will be indexed. The literals can then be searched with CLucene queries. More details regarding queries can be found in the documentation fo executeQuery().

Author:
Sebastian Trueg trueg.nosp@m.@kde.nosp@m..org

Definition at line 61 of file indexfiltermodel.h.


Constructor & Destructor Documentation

Create a new index model.

Parameters:
indexDirThe directory where the index should be stored. If the directory already contains an index, it will be used. Otherwise a new one will be created.
modelThe parent model to forward the calls to. If 0 the Model has to be set later on with FilterModel::setParentModel.

Create a new index model.

Parameters:
indexThe index to be used. The filter model will NOT take ownership of the index. The caller has to take care of deleting the index.
modelThe parent model to forward the calls to. If 0 the Model has to be set later on with FilterModel::setParentModel.

Destructor.


Member Function Documentation

Retrieve the index used by this index model.

Adds a new statement.

This will index the statement and then forward the call to the parent model. Normally only statements with literal objects are indexed. An exception are those statements with predicates that are set via setForceIndexPredicates.

Reimplemented from Soprano::FilterModel.

Removes a statement.

This will remove the statement from the index and then forward the call to the parent model.

Reimplemented from Soprano::FilterModel.

Removes statements.

This will remove the statements from the index and then forward the call to the parent model.

Reimplemented from Soprano::FilterModel.

QueryResultIterator Soprano::Index::IndexFilterModel::executeQuery ( const QString query,
Query::QueryLanguage  language,
const QString userQueryLanguage = QString() 
) const [virtual]

The IndexFilterModel is currently based on CLucene. While the index itself is available via index() and allows querying via CLucene queries it is not available over the Soprano::Client interface. Thus, CLucene queries are supported through this method and will return QueryHit objects wrapped in a QueryResultIterator.

Future versions of Soprano will support querying the index through the Soprano::Query API (still unfinished and unstable).

Parameters:
queryThe query string. This can be a CLucene query in which case the query will be passed to CLuceneIndex.
languageThe query language. Set to Soprano::Query::QueryLanguageUser for CLucene queries.
userQueryLanguageIf language equals Query::QueryLanguageUser userQueryLanguage defines the language to use. Use "lucene" to perform CLucene queries.
Returns:
An iterator over all results matching the query, on error an invalid iterator is returned. In case of a CLucene query the iterator will wrap a set of QueryHit objects through the bindings "resource" and "score".
See also:
CLuceneIndex::search()

Reimplemented from Soprano::FilterModel.

Set the number or addStatement operations that are to be cached in the index. The default value is 1 which means that no caching occurs. Be aware that query operations will always close cached transactions.

Parameters:
sizeThe number of operations that should be handled in one transaction. Set to 1 to disable.
See also:
CLuceneIndex::startTransaction, CLuceneIndex::closeTransaction

The number of addStatement operations to cache in one transaction.

See also:
setTransactionCacheSize

Rebuild the complete index. This means that the index will be cleared and all literal statements will be re-indexed.

This method is purely intended for maintenance.

Since:
2.1

Optimize the index for search. This makes sense after adding or removing a large number of statements.

See also:
CLuceneIndex::optimize
Since:
2.2

Add a predicate which should only be indexed. This might be useful for very large literals whose value is of no interest but which should be searchable.

Parameters:
predicateThe predicate that should only be indexed but not stored in the underlying Model.
See also:
indexOnlyPredicates, setIndexOnlyPredicates
Since:
2.1

Set the predicates that should only be indexed. This might be useful for very large literals whose value is of no interest but which should be searchable.

Parameters:
predicatesA list of predicates that should only be indexed but not stored in the underlying Model.
See also:
indexOnlyPredicates, addIndexOnlyPredicate
Since:
2.1

The IndexFilterModel supports to not forward certain predicates to the parent Model but only index their value. This might be useful for very large literals whose value is of no interest but which should be searchable.

Returns:
A list of predicates that will only be indexed but not stored in the underlying Model.
See also:
addIndexOnlyPredicate, setIndexOnlyPredicates
Since:
2.1

Add a predicate which should be indexed even if the object is a resource. See setForceIndexPredicates for a detailed explanation.

Parameters:
predicateThe predicate that should be indexed in any case.
See also:
forceIndexPredicates, setForceIndexPredicates
Since:
2.2

Normally only statements with a literal object are indexed when added thorugh addStatement. In some cases however, it is useful to also index resource objects.

Statement with a resource object (a URI) and a predicate that matches one of the force index predicates, are converted to strings using QUrl::toEncoded and added to the index non-tokenized. Thus, the resources will be searchable directly via a 'field:uri' query but not via the default search field.

A typical and very useful predicate is Vocabulary::RDF::type(). This allows to restrict the type of resources in lucene queries:

 model->executeQuery( QString( "foobar AND %1:%2" )
                      .arg( encodeUriForLuceneQuery( RDF::type() ) )
                      .arg( encodeUriForLuceneQuery( myType ) ),
                      Query::QueryLanguageUser,
                      "lucene" );
Parameters:
predicatesThe predicates that should be indexed in any case.
See also:
forceIndexPredicates, addForceIndexPredicate
Since:
2.2

See setForceIndexPredicates for a detailed explanation.

Returns:
A list of predicates that will be indexed even if the object is not a literal.
See also:
addForceIndexPredicate, setForceIndexPredicates
Since:
2.2

Encodes a string to be used in a lucene query. String values may contain characters that are reserved in lucene queries. These are property escaped by this method.

This method converts an arbitrary string into a string that can be used in a lucene query.

Parameters:
valueThe string to be encoded.
Returns:
An encoded and escaped string representation of the provided string.
See also:
encodeUriForLuceneQuery
Since:
2.2

Encodes a URI to be used in a lucene query. URIs often contain characters that are reserved in lucene queries and, thus, need to be escaped. In addition, the URIs are encoded by the index model for storage in clucene.

This method converts a URI into a string that can be used in a lucene query.

Parameters:
uriThe URI to be encoded.
Returns:
An encoded and escaped string representation of the URI.
See also:
encodeStringForLuceneQuery
Since:
2.2

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