WebLogic Server 6.1 API Reference

weblogic.apache.xpath.axes
Class WalkerFactory

java.lang.Object
  |
  +--weblogic.apache.xpath.axes.WalkerFactory

public class WalkerFactory

extends java.lang.Object

This class is both a factory for XPath location path expressions, which are built from the opcode map output, and an analysis engine for the location path expressions in order to provide optimization hints.

Author:

Copyright © 2001 BEA Systems, Inc. All Rights Reserved.

Field Summary

static int	BIT_ANCESTOR Bit is on if any of the walkers contain an ancestor step.
static int	BIT_ANCESTOR_OR_SELF Bit is on if any of the walkers contain an ancestor-or-self step.
static int	BIT_ANY_DESCENDANT_FROM_ROOT Found "//foo" pattern
static int	BIT_ATTRIBUTE Bit is on if any of the walkers contain an attribute step.
static int	BIT_BACKWARDS_SELF Bit is on if any of the walkers can go backwards in document order from the context node.
static int	BIT_CHILD Bit is on if any of the walkers contain a child step.
static int	BIT_DESCENDANT Bit is on if any of the walkers contain a descendant step.
static int	BIT_DESCENDANT_OR_SELF Bit is on if any of the walkers contain a descendant-or-self step.
static int	BIT_FILTER Bit is on if any of the walkers contain a filter (i.e.
static int	BIT_FOLLOWING Bit is on if any of the walkers contain a following step.
static int	BIT_FOLLOWING_SIBLING Bit is on if any of the walkers contain a following-sibiling step.
static int	BIT_MATCH_PATTERN Bit is on if the expression is a match pattern.
static int	BIT_NAMESPACE Bit is on if any of the walkers contain a namespace step.
static int	BIT_NODETEST_ANY Bit is on if any of the walkers contain an node() test.
static int	BIT_PARENT Bit is on if any of the walkers contain a parent step.
static int	BIT_PRECEDING Bit is on if any of the walkers contain a preceding step.
static int	BIT_PRECEDING_SIBLING Bit is on if any of the walkers contain a preceding-sibling step.
static int	BIT_PREDICATE Bit is on if the expression contains a top-level predicate.
static int	BIT_ROOT Bit is on if any of the walkers contain a root step.
static int	BIT_SELF Bit is on if any of the walkers contain a self step.
static int	BITMASK_TRAVERSES_OUTSIDE_SUBTREE If any of these bits are on, the expression may likely traverse outside the given subtree.
static int	BITS_COUNT First 8 bits are the number of top-level location steps.
static int	BITS_RESERVED 4 bits are reserved for future use.

Constructor Summary

WalkerFactory()

Method Summary

static LocPathIterator

newLocPathIterator(Compiler compiler, int opPos) Create a new LocPathIterator iterator.

Methods inherited from class java.lang.Object

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

Field Detail

BITS_COUNT

public static final int BITS_COUNT

First 8 bits are the number of top-level location steps. Hopefully there will never be more that 255 location steps!!!

BITS_RESERVED

public static final int BITS_RESERVED

4 bits are reserved for future use.

BIT_PREDICATE

public static final int BIT_PREDICATE

Bit is on if the expression contains a top-level predicate.

BIT_ANCESTOR

public static final int BIT_ANCESTOR

Bit is on if any of the walkers contain an ancestor step.

BIT_ANCESTOR_OR_SELF

public static final int BIT_ANCESTOR_OR_SELF

Bit is on if any of the walkers contain an ancestor-or-self step.

BIT_ATTRIBUTE

public static final int BIT_ATTRIBUTE

Bit is on if any of the walkers contain an attribute step.

BIT_CHILD

public static final int BIT_CHILD

Bit is on if any of the walkers contain a child step.

BIT_DESCENDANT

public static final int BIT_DESCENDANT

Bit is on if any of the walkers contain a descendant step.

BIT_DESCENDANT_OR_SELF

public static final int BIT_DESCENDANT_OR_SELF

Bit is on if any of the walkers contain a descendant-or-self step.

BIT_FOLLOWING

public static final int BIT_FOLLOWING

Bit is on if any of the walkers contain a following step.

BIT_FOLLOWING_SIBLING

public static final int BIT_FOLLOWING_SIBLING

Bit is on if any of the walkers contain a following-sibiling step.

BIT_NAMESPACE

public static final int BIT_NAMESPACE

Bit is on if any of the walkers contain a namespace step.

BIT_PARENT

public static final int BIT_PARENT

Bit is on if any of the walkers contain a parent step.

BIT_PRECEDING

public static final int BIT_PRECEDING

Bit is on if any of the walkers contain a preceding step.

BIT_PRECEDING_SIBLING

public static final int BIT_PRECEDING_SIBLING

Bit is on if any of the walkers contain a preceding-sibling step.

BIT_SELF

public static final int BIT_SELF

Bit is on if any of the walkers contain a self step.

BIT_FILTER

public static final int BIT_FILTER

Bit is on if any of the walkers contain a filter (i.e. id(), extension function, etc.) step.

BIT_ROOT

public static final int BIT_ROOT

Bit is on if any of the walkers contain a root step.

BITMASK_TRAVERSES_OUTSIDE_SUBTREE

public static final int BITMASK_TRAVERSES_OUTSIDE_SUBTREE

If any of these bits are on, the expression may likely traverse outside the given subtree.

BIT_BACKWARDS_SELF

public static final int BIT_BACKWARDS_SELF

Bit is on if any of the walkers can go backwards in document order from the context node.

BIT_ANY_DESCENDANT_FROM_ROOT

public static final int BIT_ANY_DESCENDANT_FROM_ROOT

Found "//foo" pattern

BIT_NODETEST_ANY

public static final int BIT_NODETEST_ANY

Bit is on if any of the walkers contain an node() test. This is really only useful if the count is 1.

BIT_MATCH_PATTERN

public static final int BIT_MATCH_PATTERN

Bit is on if the expression is a match pattern.

Constructor Detail

WalkerFactory

public WalkerFactory()

Method Detail

newLocPathIterator

public static LocPathIterator newLocPathIterator(Compiler compiler,
                                                 int opPos)
                                          throws javax.xml.transform.TransformerException

Create a new LocPathIterator iterator. The exact type of iterator returned is based on an analysis of the XPath operations.

Parameters:

compiler - non-null reference to compiler object that has processed the XPath operations into an opcode map.

opPos - The position of the operation code for this itterator.

Returns:

non-null reference to a LocPathIterator or derivative.

Throws:

javax.xml.transform.TransformerException -