org.basex.query.xpath.internal
Class FTIndex

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.xpath.expr.Expr
          org.basex.query.xpath.expr.FTArrayExpr
              org.basex.query.xpath.internal.FTIndex

public final class FTIndex
extends FTArrayExpr

This expression retrieves the ids of indexed fulltext terms.

Author:

Workgroup DBIS, University of Konstanz 2005-08, ISC License, Sebastian Gath, Christian Gruen

Field Summary

Fields inherited from class org.basex.query.xpath.expr.FTArrayExpr

fto

Constructor Summary

FTIndex(byte[] tok, FTOpt o)
Constructor.

Method Summary

Bln	eval(XPContext ctx) Evaluates the expression with the specified context set.
FTArrayExpr	indexEquivalent(XPContext ctx, Step curr, boolean seq) Returns an equivalent expression which accesses an index structure.
int	indexSizes(XPContext ctx, Step curr, int min) Returns the number of results if this query is evaluated by an index.
boolean	more() Checks for more results.
FTNode	next(XPContext ctx) Returns the next ftquery result.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
java.lang.String	toString()

Methods inherited from class org.basex.query.xpath.expr.FTArrayExpr

comp, indexOptions, pos, usesPos, usesSize

Methods inherited from class org.basex.query.xpath.expr.Expr

returnedValue, sameAs

Methods inherited from class org.basex.query.ExprInfo

color, info, name

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FTIndex

public FTIndex(byte[] tok,
               FTOpt o)

Constructor.

Parameters:

tok - index token

o - FTOption for index token

Method Detail

indexEquivalent

public FTArrayExpr indexEquivalent(XPContext ctx,
                                   Step curr,
                                   boolean seq)

Description copied from class: Expr

Returns an equivalent expression which accesses an index structure.

Overrides:

indexEquivalent in class FTArrayExpr

Parameters:

ctx - root

curr - location step

seq - flag for sequential evaluation

Returns:

Equivalent index-expression or null

eval

public Bln eval(XPContext ctx)

Description copied from class: Expr

Evaluates the expression with the specified context set. Additionally provides a context

Specified by:

eval in class Expr

Parameters:

ctx - query context

Returns:

resulting XPathValue

more

public boolean more()

Description copied from class: FTArrayExpr

Checks for more results.

Overrides:

more in class FTArrayExpr

Returns:

boolean

next

public FTNode next(XPContext ctx)

Description copied from class: FTArrayExpr

Returns the next ftquery result.

Overrides:

next in class FTArrayExpr

Parameters:

ctx - current context

Returns:

FTNode container for the next result

indexSizes

public int indexSizes(XPContext ctx,
                      Step curr,
                      int min)

Description copied from class: Expr

Returns the number of results if this query is evaluated by an index. If Integer.MAX_VALUE is returned, no index access is possible.

Overrides:

indexSizes in class Expr

Parameters:

ctx - root

curr - the current location step

min - current minimum index hits

Returns:

number of expected results

plan

public void plan(Serializer ser)
          throws java.io.IOException

Description copied from class: ExprInfo

Recursively sends the abstract syntax of this expression to the specified serializer.

Overrides:

plan in class FTArrayExpr

Parameters:

ser - serializer

Throws:

java.io.IOException - exception

toString

public java.lang.String toString()

Overrides:

toString in class FTArrayExpr