lux

Class CachingDocReader

java.lang.Object

lux.CachingDocReader

public class CachingDocReader
extends Object

Reads, parses and caches XML documents from a Lucene index. Assigns Lucene docIDs as Saxon document numbers. This reader and its cache are intended to survive for a single query only, and is *not thread-safe*.

Constructor Summary

Constructors

Constructor and Description
CachingDocReader(net.sf.saxon.s9api.DocumentBuilder builder, net.sf.saxon.Configuration config, IndexConfiguration indexConfig) Create a CachingDocReader that will use the provided objects to read and parse XML documents.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clears all cached documents.
net.sf.saxon.s9api.XdmNode	createXdmNode(long docID, String uri, String xml, byte[] bytes) Either the xml or the bytes parameter carries the document contents.
net.sf.saxon.s9api.XdmNode	get(int leafDocID, org.apache.lucene.index.AtomicReaderContext context) Reads the document with the given relative id from an atomic reader.
net.sf.saxon.s9api.XdmNode	get(int docID, org.apache.lucene.index.IndexReader reader) Reads the document with the given id from a top-level reader.
net.sf.saxon.s9api.XdmNode	get(long docID)
long	getBuildTime()
int	getCacheHits()
int	getCacheMisses()

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingDocReader

public CachingDocReader(net.sf.saxon.s9api.DocumentBuilder builder,
                net.sf.saxon.Configuration config,
                IndexConfiguration indexConfig)

Create a CachingDocReader that will use the provided objects to read and parse XML documents.

Parameters:

builder - will be used to construct XML documents as XdmNodes

config - assigns the proper document ID to each constructed document

indexConfig - supplies the names of the xml storage and uri fields

Method Detail

get

public net.sf.saxon.s9api.XdmNode get(int leafDocID,
                             org.apache.lucene.index.AtomicReaderContext context)
                               throws IOException

Reads the document with the given relative id from an atomic reader. If cached, the cached copy is returned. Otherwise the document is read from the index. If the document does not exist in the index, or has been deleted, results are not well-defined: see IndexReader.

Parameters:

leafDocID - the relative docid of the document to read

context - an atomic Lucene index reader context (a leaf of the segmented index tree)

Returns:

the document, as a Saxon XdmNode

Throws:

IOException - if there is some sort of low-level problem with the index

LuxException - if there is an error building the document that has been retrieved

get

public net.sf.saxon.s9api.XdmNode get(int docID,
                             org.apache.lucene.index.IndexReader reader)
                               throws IOException

Reads the document with the given id from a top-level reader. If cached, the cached copy is returned. Otherwise the document is read from the index. If the document does not exist in the index, or has been deleted, results are not well-defined: see IndexReader.

Parameters:

docID - the absolute docid of the document to read

reader - the Lucene index reader

Returns:

the document, as a Saxon XdmNode

Throws:

IOException - if there is some sort of low-level problem with the index

LuxException - if there is an error building the document that has been retrieved

get

public net.sf.saxon.s9api.XdmNode get(long docID)

Parameters:

docID -

Returns:

a document from the cache, or null if no document matching the docID is in the cache

createXdmNode

public net.sf.saxon.s9api.XdmNode createXdmNode(long docID,
                                       String uri,
                                       String xml,
                                       byte[] bytes)

Either the xml or the bytes parameter carries the document contents. If the xml is non-null, it is assumed to be a serialized XML document, and is parsed. If the bytes is non-null and begins with a tinybin signature, it is interpreted as tiny binary. Otherwise, the bytes are treated as a binary (non-XML) document. If both xml and bytes are null, a warning is logged and an empty binary document created.

Parameters:

docID - The Solr/Lucene docid; or a shard/docid combo under Solr Cloud

uri - The uri path (no scheme) of the document to create

xml - The contents of the document, if an XML document

bytes - The contents of the document

Returns:

a new document made from the arguments

getCacheHits

public int getCacheHits()

Returns:

the number of items retrieved from the cache

getCacheMisses

public int getCacheMisses()

Returns:

the number of items retrieved and added to the cache

getBuildTime

public long getBuildTime()

Returns:

the total time spent building documents (in nanoseconds). This includes time spent parsing and constructing a Saxon NodeInfo/XdmNode.

clear

public void clear()

Clears all cached documents.