com.yahoo.prelude.semantics

Class SemanticSearcher

java.lang.Object

com.yahoo.component.AbstractComponent

com.yahoo.component.chain.ChainedComponent

com.yahoo.processing.Processor

com.yahoo.search.Searcher

com.yahoo.prelude.semantics.SemanticSearcher

All Implemented Interfaces:

com.yahoo.component.Component, Comparable<com.yahoo.component.Component>

public class SemanticSearcher
extends Searcher

Analyzes query semantics and enhances the query to reflect findings

Author:

bratseth

Field Summary

Fields

Modifier and Type	Field and Description
private RuleBase	defaultRuleBase The default rule base of this
private Map<String,RuleBase>	ruleBases All rule bases of this (always including the default)
private static com.yahoo.processing.request.CompoundName	rulesOff
private static com.yahoo.processing.request.CompoundName	rulesRulebase
private static com.yahoo.processing.request.CompoundName	tracelevelRules

Fields inherited from class com.yahoo.component.AbstractComponent

isDeconstructable

Constructor Summary

Constructors

Constructor and Description
SemanticSearcher(List<RuleBase> ruleBases)
SemanticSearcher(RuleBase... ruleBases)
SemanticSearcher(RuleBase ruleBase) Creates a semantic searcher using the given default rule base
SemanticSearcher(SemanticRulesConfig config)

Method Summary

Modifier and Type	Method and Description
RuleBase	getDefaultRuleBase() Returns the default rule base
RuleBase	getRuleBase(String ruleBaseName) Returns the rule base of the given name, or null if none.
private Result	handleError(RuleBase ruleBase, Query query, String error)
private RuleBase	resolveRuleBase(Query query)
Result	search(Query query, Execution execution) Override this to implement your searcher.
private static List<RuleBase>	toList(SemanticRulesConfig config)

Methods inherited from class com.yahoo.search.Searcher

ensureFilled, fill, getLogger, process, toString

Methods inherited from class com.yahoo.component.chain.ChainedComponent

getAnnotatedDependencies, getDefaultAnnotatedDependencies, getDependencies, initDependencies

Methods inherited from class com.yahoo.component.AbstractComponent

clone, compareTo, deconstruct, getClassName, getId, getIdString, hasInitializedId, initId, isDeconstructable, setIsDeconstructable

Methods inherited from class java.lang.Object

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

Field Detail

rulesRulebase

private static final com.yahoo.processing.request.CompoundName rulesRulebase

rulesOff

private static final com.yahoo.processing.request.CompoundName rulesOff

tracelevelRules

private static final com.yahoo.processing.request.CompoundName tracelevelRules

defaultRuleBase

private RuleBase defaultRuleBase

The default rule base of this

ruleBases

private final Map<String,RuleBase> ruleBases

All rule bases of this (always including the default)

Constructor Detail

SemanticSearcher

public SemanticSearcher(RuleBase ruleBase)

Creates a semantic searcher using the given default rule base

SemanticSearcher

public SemanticSearcher(RuleBase... ruleBases)

SemanticSearcher

@Inject
public SemanticSearcher(SemanticRulesConfig config)

SemanticSearcher

public SemanticSearcher(List<RuleBase> ruleBases)

Method Detail

toList

private static List<RuleBase> toList(SemanticRulesConfig config)

search

public Result search(Query query,
                     Execution execution)

Description copied from class: Searcher

Override this to implement your searcher.

Searcher implementation subclasses will, depending on their type of logic, do one of the following:

• Query processors: Access the query, then call execution.search and return the result
• Result processors: Call execution.search to get the result, access it and return
• Sources (which produces results): Create a result, add the desired hits and return it.
• Federators (which forwards the search to multiple subchains): Call search on the desired subchains in parallel and get the results. Combine the results to one and return it.
• Workflows: Call execution.search as many times as desired, using different queries. Eventually return a result.

Hits come in two kinds - concrete hits are actual content of the kind requested by the user, meta hits are hits which provides information about the collection of hits, on the query, the service and so on.

The query specifies a window into a larger result list that must be returned from the searcher through hits and offset; Searchers which returns list of hits in the top level in the result must return at least hits number of hits (or if impossible; all that are available), starting at the given offset. In addition, searchers are allowed to return any number of meta hits (although this number is expected to be low). For hits contained in nested hit groups, the concept of a window defined by hits and offset is not well defined and does not apply.

Error handling in searchers:

• Unexpected events: Throw any RuntimeException. This query will fail with the exception message, and the error will be logged
• Expected events: Create (new Result(Query, ErrorMessage) or add result.setErrorIfNoOtherErrors(ErrorMessage) an error message to the Result.
• Recoverable user errors: Add a FeedbackHit explaining the condition and how to correct it.

Specified by:

search in class Searcher

Parameters:

query - the query

Returns:

the result of making this query

resolveRuleBase

private RuleBase resolveRuleBase(Query query)

handleError

private Result handleError(RuleBase ruleBase,
                           Query query,
                           String error)

getDefaultRuleBase

public RuleBase getDefaultRuleBase()

Returns the default rule base

getRuleBase

public RuleBase getRuleBase(String ruleBaseName)

Returns the rule base of the given name, or null if none. The part of the name following the last dot (if any) is removed before lookup.