org.cdlib.xtf.lazyTree

Class LazyKeyManager

Object

KeyManager

LazyKeyManager

All Implemented Interfaces:

Serializable

public class LazyKeyManager
extends KeyManager

LazyKeyManager wraps a Saxon KeyManager, but stores keys on disk instead of keeping them in RAM. If the same index is accessed later, it need not be recomputed.

Author:

Martin Haye

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private int	nKeysStored Count of keys actually stored on disk

Fields inherited from class KeyManager

keyList

Constructor Summary

Constructors

Constructor and Description
LazyKeyManager(Configuration config, KeyManager prevMgr) Construct and initialize the manager, grabbing existing key definitions from the previous key manager.

Method Summary

Modifier and Type	Method and Description
Map	buildIndex(int keyNameFingerprint, BuiltInAtomicType itemType, Set foundItemTypes, DocumentInfo doc, XPathContext context) Build the index for a particular document for a named key
private String	calcIndexName(NamePool pool, String fingerName, List definitions, Configuration config) Calculates a string name for a given set of xsl:key definitions.
protected void	constructIndex(DocumentInfo doc, Map index, KeyDefinition keydef, BuiltInAtomicType soughtItemType, Set foundItemTypes, XPathContext context, boolean isFirst) Optimized to use node test directly when possible, for speed.
int	createAllKeys(LazyDocument doc, XPathContext context) Called after creation of a lazy tree during the index process.
static LazyDocument	getDocumentImpl(DocumentInfo doc) Retrieve the lazy document for the given doc, if possible.
boolean	isEmpty() Tells whether any keys have been registered.

Methods inherited from class KeyManager

addKeyDefinition, explainKeys, getKeyDefinitions, selectByKey

Methods inherited from class Object

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

Field Detail

nKeysStored

private int nKeysStored

Count of keys actually stored on disk

Constructor Detail

LazyKeyManager

public LazyKeyManager(Configuration config,
                      KeyManager prevMgr)

Construct and initialize the manager, grabbing existing key definitions from the previous key manager.

Method Detail

buildIndex

public Map buildIndex(int keyNameFingerprint,
                      BuiltInAtomicType itemType,
                      Set foundItemTypes,
                      DocumentInfo doc,
                      XPathContext context)
               throws XPathException

Description copied from class: KeyManager

Build the index for a particular document for a named key

Overrides:

buildIndex in class KeyManager

Parameters:

keyNameFingerprint - The fingerprint of the name of the required key

itemType - the type of the values to be indexed.

doc - The source document in question

context - The dynamic context

Returns:

the index in question, as a Map mapping a key value onto a ArrayList of nodes

Throws:

XPathException

constructIndex

protected void constructIndex(DocumentInfo doc,
                              Map index,
                              KeyDefinition keydef,
                              BuiltInAtomicType soughtItemType,
                              Set foundItemTypes,
                              XPathContext context,
                              boolean isFirst)
                       throws XPathException

Optimized to use node test directly when possible, for speed.

Overrides:

constructIndex in class KeyManager

Throws:

XPathException

isEmpty

public boolean isEmpty()

Tells whether any keys have been registered.

createAllKeys

public int createAllKeys(LazyDocument doc,
                         XPathContext context)
                  throws XPathException

Called after creation of a lazy tree during the index process. Iterates through all registered keys, and builds the associated disk-based key indexes on the given tree.

Parameters:

doc - The LazyTree to work on.

context - Context used for name pool, etc.

Returns:

int The number of keys created

Throws:

XPathException

getDocumentImpl

public static LazyDocument getDocumentImpl(DocumentInfo doc)

Retrieve the lazy document for the given doc, if possible.

calcIndexName

private String calcIndexName(NamePool pool,
                             String fingerName,
                             List definitions,
                             Configuration config)

Calculates a string name for a given set of xsl:key definitions. This is done very carefully to ensure that the same key will generate the same name, regardless of ephemeral things like particular name codes or other variables that might be different on a different run.

Parameters:

pool - Name pool used to look up names

fingerName - Fingerprint of the key

definitions - List of key definitions

config - Associated Saxon configuration

Returns:

A unique string for this xsl:key