lux
Class Optimizer

java.lang.Object
  net.sf.saxon.expr.parser.Optimizer
      lux.Optimizer

All Implemented Interfaces:

Serializable

public class Optimizer
extends net.sf.saxon.expr.parser.Optimizer

This Optimizer provides asserts that search results are sorted in document order (when they are), so they don't have to be re-sorted by Saxon. For use with Saxon HE only: PE/EE provide their own, and the optimization provided here is not compatible with those. There is no need for users of these classes to create this explicitly - it is managed by Evaluator.

See Also:

Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.expr.parser.Optimizer

config, FULL_OPTIMIZATION, NO_OPTIMIZATION

Constructor Summary

Optimizer(net.sf.saxon.Configuration config, SaxonTranslator translator)

Method Summary

net.sf.saxon.expr.Expression

makeConditionalDocumentSorter(net.sf.saxon.expr.sort.DocumentSorter sorter, net.sf.saxon.expr.SlashExpression path) Make a conditional document sorter.

Methods inherited from class net.sf.saxon.expr.parser.Optimizer

compileToByteCode, convertPathExpressionToKey, convertToFilterExpression, extractGlobalVariables, generateMultithreadedInstruction, getConfiguration, getOptimizationLevel, isIndexableFilter, isVariableReplaceableByDot, makeCastableToList, makeCastableToUnion, makeCastToList, makeCastToUnion, makeCopyOperationsExplicit, makeIndexedValue, makeInversion, makeOuterForExpression, makeStreamingApplyTemplates, optimizeCopy, optimizeForExpressionForStreaming, optimizeGeneralComparison, optimizeQuantifiedExpressionForStreaming, promoteExpressionsToGlobal, setOptimizationLevel, trace, trace, tryIndexedFilter, tryInlineFunctionCall, trySwitch

Methods inherited from class java.lang.Object

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

Constructor Detail

Optimizer

public Optimizer(net.sf.saxon.Configuration config,
                 SaxonTranslator translator)

Method Detail

makeConditionalDocumentSorter

public net.sf.saxon.expr.Expression makeConditionalDocumentSorter(net.sf.saxon.expr.sort.DocumentSorter sorter,
                                                                  net.sf.saxon.expr.SlashExpression path)

Make a conditional document sorter. This optimization is attempted when a DocumentSorter is wrapped around a path expression. Saxon-HE doesn't provide any optimizations of this sort, but this is critical for lux:search expressions since they may potentially return a huge number of unused documents.

Overrides:

makeConditionalDocumentSorter in class net.sf.saxon.expr.parser.Optimizer

Parameters:

sorter - the document sorter

path - the path expression

Returns:

the path expression, if it is proven to be in document order, or the original sorter unchanged when no such optimization is possible