Package com.yahoo.searchlib.rankingexpression.evaluation.gbdtoptimization

Class GBDTOptimizer

java.lang.Object

com.yahoo.searchlib.rankingexpression.evaluation.Optimizer

com.yahoo.searchlib.rankingexpression.evaluation.gbdtoptimization.GBDTOptimizer

public class GBDTOptimizer
extends Optimizer

This ranking expression processor recognizes and optimizes GBDT expressions. Note that this optimization is destructive - inspection is not possible into optimized subtrees.

This class is not multithread safe.

Author:

bratseth

Constructor Summary

Constructors

Constructor	Description
GBDTOptimizer()

Method Summary

Modifier and Type	Method	Description
void	optimize(RankingExpression expression, ContextIndex context, OptimizationReport report)	Optimizes this by replacing GBDT sub-expressions by GBDTNodes.

Methods inherited from class com.yahoo.searchlib.rankingexpression.evaluation.Optimizer

isEnabled, setEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

GBDTOptimizer

public GBDTOptimizer()

Method Detail

optimize

public void optimize(RankingExpression expression,
                     ContextIndex context,
                     OptimizationReport report)

Optimizes this by replacing GBDT sub-expressions by GBDTNodes. These optimized expressions must be executed using an instance of ArrayContext as context. These thread locally reusable contexts must be created from the ranking expression before the ranking expression is optimized.

Specified by:

optimize in class Optimizer

Parameters:

expression - the expression to destructively optimize

context - a fast lookup context created from the given expression

report - the optimization report to which actions of this is logged