Class BlendingSearcher
- java.lang.Object
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- com.yahoo.component.AbstractComponent
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- com.yahoo.component.chain.ChainedComponent
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- com.yahoo.processing.Processor
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- com.yahoo.search.Searcher
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- com.yahoo.prelude.searcher.BlendingSearcher
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- All Implemented Interfaces:
com.yahoo.component.Component
,com.yahoo.component.Deconstructable
,Comparable<com.yahoo.component.Component>
public class BlendingSearcher extends Searcher
Flattens a result consisting of multiple hit groups containing hits into a single flat list of hits.- Author:
- Bob Travis, Steinar Knutsen, Arne Fossaa
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Constructor Summary
Constructors Constructor Description BlendingSearcher(com.yahoo.component.ComponentId id, com.yahoo.container.QrSearchersConfig cfg)
BlendingSearcher(String blendingField)
Only for legacy tests.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected Result
blendResults(Result result, Query q, int offset, int hits, Execution execution)
Produce a single blended hit list from a group of hitgroups.void
fill(Result result, String summaryClass, Execution execution)
Fills this result by forwarding to the right chained searchersResult
search(Query query, Execution execution)
Override this to implement your searcher.-
Methods inherited from class com.yahoo.search.Searcher
ensureFilled, getLogger, process, toString
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Methods inherited from class com.yahoo.component.chain.ChainedComponent
getAnnotatedDependencies, getDefaultAnnotatedDependencies, getDependencies, initDependencies
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Field Detail
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BLENDING
public static final String BLENDING
- See Also:
- Constant Field Values
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Constructor Detail
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BlendingSearcher
@Inject public BlendingSearcher(com.yahoo.component.ComponentId id, com.yahoo.container.QrSearchersConfig cfg)
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BlendingSearcher
public BlendingSearcher(String blendingField)
Only for legacy tests.
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Method Detail
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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.
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fill
public void fill(Result result, String summaryClass, Execution execution)
Fills this result by forwarding to the right chained searchers
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