lux

Class Evaluator

java.lang.Object

lux.Evaluator

public class Evaluator
extends Object

This class holds all the per-request state required for evaluating queries. It is *not* thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Evaluator.LuxCollectionURIResolver

Field Summary

Fields

Modifier and Type	Field and Description
static String	LUX_NAMESPACE

Constructor Summary

Constructors

Constructor and Description
Evaluator() Creates a query evaluator that has no association with an index (no searcher or writer).
Evaluator(Compiler compiler, LuxSearcher searcher, DocWriter docWriter) Creates an evaluator that uses the provided objects to evaluate queries.

Method Summary

Methods

Modifier and Type	Method and Description
net.sf.saxon.s9api.XdmNode	build(InputStream xml, String uri) Build a document as a Saxon XdmNode.
net.sf.saxon.s9api.XdmNode	build(Reader xml, String uri) Build a document as a Saxon XdmNode.
void	close() Call this method to release the Evaluator from its role as the URI and Collection URI Resolver, and to close the underlying Lucene Searcher.
static Evaluator	createEvaluator(org.apache.lucene.store.Directory dir) Creates a query evaluator that searches and writes to the given Directory (Lucene index).
XdmResultSet	evaluate(String query) Compile and evaluate the given query, as XQuery, with no context defined.
XdmResultSet	evaluate(String query, QueryContext context)
XdmResultSet	evaluate(net.sf.saxon.s9api.XQueryExecutable xquery) Evaluate the already-compiled query, with no context defined.
XdmResultSet	evaluate(net.sf.saxon.s9api.XQueryExecutable xquery, QueryContext context)
Compiler	getCompiler()
net.sf.saxon.s9api.DocumentBuilder	getDocBuilder()
CachingDocReader	getDocReader()
DocWriter	getDocWriter()
TransformErrorListener	getErrorListener()
LuxQueryParser	getLuxQueryParser()
QueryContext	getQueryContext()
QueryStats	getQueryStats()
LuxSearcher	getSearcher()
XmlQueryParser	getXmlQueryParser()
Iterator<net.sf.saxon.s9api.XdmItem>	iterator(net.sf.saxon.s9api.XQueryExecutable xquery, QueryContext context) Evaluate the already-compiled query
void	reopenSearcher() reopen the searcher so it sees any updates.
void	setQueryStats(QueryStats queryStats)

Methods inherited from class java.lang.Object

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

Field Detail

LUX_NAMESPACE

public static final String LUX_NAMESPACE

See Also:

Constant Field Values

Constructor Detail

Evaluator

public Evaluator(Compiler compiler,
         LuxSearcher searcher,
         DocWriter docWriter)

Creates an evaluator that uses the provided objects to evaluate queries.

Parameters:

compiler - queries are compiled using this

searcher - search operations required by evaluated queries are carried out using this

docWriter - this writer is used to modify the index (write, delete documents). It must be tied to the same index as the searcher.

Evaluator

public Evaluator()

Creates a query evaluator that has no association with an index (no searcher or writer). A searcher must be supplied in order to compile or evaluate queries that are optimized for use with a Lux (Lucene) index. This constructor is used in testing, or may be useful for compiling and executing queries that don't rely on documents stored in Lucene.

Method Detail

createEvaluator

public static Evaluator createEvaluator(org.apache.lucene.store.Directory dir)
                                 throws IOException

Creates a query evaluator that searches and writes to the given Directory (Lucene index). The Directory is opened and locked; the Evaluator must be closed when it is no longer in use.

Parameters:

dir - the directory where documents are to be searched, store and retrieved

Returns:

the new Evaluator

Throws:

IOException - if the Directory cannot be opened

close

public void close()

Call this method to release the Evaluator from its role as the URI and Collection URI Resolver, and to close the underlying Lucene Searcher.

evaluate

public XdmResultSet evaluate(String query)

Compile and evaluate the given query, as XQuery, with no context defined.

Parameters:

query - an XQuery expression (main module)

Returns:

the results of the evaluation; any errors are encapsulated in the result set.

evaluate

public XdmResultSet evaluate(String query,
                    QueryContext context)

evaluate

public XdmResultSet evaluate(net.sf.saxon.s9api.XQueryExecutable xquery)

Evaluate the already-compiled query, with no context defined.

Parameters:

xquery - a compiled XQuery expression

Returns:

the results of the evaluation; any errors are encapsulated in the result set.

evaluate

public XdmResultSet evaluate(net.sf.saxon.s9api.XQueryExecutable xquery,
                    QueryContext context)

iterator

public Iterator<net.sf.saxon.s9api.XdmItem> iterator(net.sf.saxon.s9api.XQueryExecutable xquery,
                                            QueryContext context)

Evaluate the already-compiled query

Parameters:

xquery - a compiled XQuery expression

context - the dynamic query context

Returns:

an iterator over the results of the evaluation.

build

public net.sf.saxon.s9api.XdmNode build(Reader xml,
                               String uri)

Build a document as a Saxon XdmNode. The document will be given a generated id outside the space of ids reserved for indexed documents.

Parameters:

xml - the document content

uri - the document uri

Returns:

the constructed document

Throws:

LuxException - if any error occurs (such as an XML parse error).

build

public net.sf.saxon.s9api.XdmNode build(InputStream xml,
                               String uri)

Build a document as a Saxon XdmNode. The document will be given a generated id outside the space of ids reserved for indexed documents.

Parameters:

xml - the document content

uri - the document uri

Returns:

the constructed document

Throws:

LuxException - if any error occurs (such as an XML parse error).

reopenSearcher

public void reopenSearcher()

reopen the searcher so it sees any updates. Do NOT call this when operating within Solr: it interferes with Solr's management of open searchers/readers.

getCompiler

public Compiler getCompiler()

getDocReader

public CachingDocReader getDocReader()

getDocBuilder

public net.sf.saxon.s9api.DocumentBuilder getDocBuilder()

getDocWriter

public DocWriter getDocWriter()

getSearcher

public LuxSearcher getSearcher()

getQueryStats

public QueryStats getQueryStats()

setQueryStats

public void setQueryStats(QueryStats queryStats)

getLuxQueryParser

public LuxQueryParser getLuxQueryParser()

Returns:

a new parser, which will be cached for re-use, or the cached parser

getXmlQueryParser

public XmlQueryParser getXmlQueryParser()

Returns:

a new parser, which will be cached for re-use, or the cached parser

getErrorListener

public TransformErrorListener getErrorListener()

Returns:

the error listener that receives static and dynamic error events.

getQueryContext

public QueryContext getQueryContext()

Returns:

the context associated with this query; wraps the variable bindings, namespace declarations, and the Solr XQueryComponent if this is a distributed query running via SolrCloud.