com.yahoo.search.querytransform

Class LegacyCombinator

java.lang.Object

com.yahoo.component.AbstractComponent

com.yahoo.component.chain.ChainedComponent

com.yahoo.processing.Processor

com.yahoo.search.Searcher

com.yahoo.search.querytransform.LegacyCombinator

All Implemented Interfaces:

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

public class LegacyCombinator
extends Searcher

Compatibility layer to implement the old multi part query syntax, along with the features of QueryCombinator. Do not use both QueryCombinator and LegacyCombinator in a single search.

A searcher which grabs query parameters of the form "defidx.(identifier)=(index name)" and "query.(identifier)=(user query)", parses them and adds them as AND items to the query root.

If the given default index does not exist in the search definition, the query part will be parsed with the settings of the default index set to "".

If any of the following arguments exist, they will be used:

query.(identifier)=query string
query.(identifier).operator={"req", "rank", "not"}, where "req" is default
query.(identifier).defidx=default index
query.(identifier).type={"all", "any", "phrase", "adv", "web"} where "all" is default

If both defidx.(identifier) and any of query.(identifier).{operator,defidx,type} is present in the query, an InvalidQueryParameter error will be added, and the query will be passed through untransformed.

Author:

Steinar Knutsen

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	LegacyCombinator.Combinator
private static class	LegacyCombinator.QueryPart

Field Summary

Fields

Modifier and Type	Field and Description
private static String	DEFIDXPREFIX
private static String	DEFIDXSUFFIX
private static String	OPERATORSUFFIX
private static String	QUERYPREFIX
private static String	TYPESUFFIX

Fields inherited from class com.yahoo.component.AbstractComponent

isDeconstructable

Constructor Summary

Constructors

Constructor and Description
LegacyCombinator()

Method Summary

Modifier and Type	Method and Description
private static void	addAndItem(QueryTree queryTree, Item item)
private void	addAndItems(com.yahoo.language.Language language, Query query, Iterable<LegacyCombinator.QueryPart> pieces, IndexFacts.Session session, Execution.Context context)
private void	addNotItem(QueryTree queryTree, Item item)
private void	addNotItems(com.yahoo.language.Language language, Query query, Set<LegacyCombinator.QueryPart> pieces, IndexFacts.Session session, Execution.Context context)
private void	addRankItem(QueryTree queryTree, Item item)
private void	addRankItems(com.yahoo.language.Language language, Query query, Set<LegacyCombinator.QueryPart> pieces, IndexFacts.Session session, Execution.Context context)
private static void	assignDefaultIndex(Item item, String defaultIndex)
private String	defaultIndex(IndexFacts.Session indexFacts, LegacyCombinator.QueryPart part)
private static Set<LegacyCombinator.QueryPart>	findQuerySnippets(Properties properties)
private static boolean	hasDots(String name)
private Item	parse(com.yahoo.language.Language language, Query query, LegacyCombinator.QueryPart part, String defaultIndex, Execution.Context context)
Result	search(Query query, Execution execution) Override this to implement your searcher.
private void	setDefaultIndex(LegacyCombinator.QueryPart part, String defaultIndex, Item item)

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

TYPESUFFIX

private static final String TYPESUFFIX

See Also:

Constant Field Values

OPERATORSUFFIX

private static final String OPERATORSUFFIX

See Also:

Constant Field Values

DEFIDXSUFFIX

private static final String DEFIDXSUFFIX

See Also:

Constant Field Values

DEFIDXPREFIX

private static final String DEFIDXPREFIX

See Also:

Constant Field Values

QUERYPREFIX

private static final String QUERYPREFIX

See Also:

Constant Field Values

Constructor Detail

LegacyCombinator

public LegacyCombinator()

Method Detail

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

addNotItems

private void addNotItems(com.yahoo.language.Language language,
                         Query query,
                         Set<LegacyCombinator.QueryPart> pieces,
                         IndexFacts.Session session,
                         Execution.Context context)

addNotItem

private void addNotItem(QueryTree queryTree,
                        Item item)

addRankItems

private void addRankItems(com.yahoo.language.Language language,
                          Query query,
                          Set<LegacyCombinator.QueryPart> pieces,
                          IndexFacts.Session session,
                          Execution.Context context)

addRankItem

private void addRankItem(QueryTree queryTree,
                         Item item)

addAndItems

private void addAndItems(com.yahoo.language.Language language,
                         Query query,
                         Iterable<LegacyCombinator.QueryPart> pieces,
                         IndexFacts.Session session,
                         Execution.Context context)

setDefaultIndex

private void setDefaultIndex(LegacyCombinator.QueryPart part,
                             String defaultIndex,
                             Item item)

parse

private Item parse(com.yahoo.language.Language language,
                   Query query,
                   LegacyCombinator.QueryPart part,
                   String defaultIndex,
                   Execution.Context context)

defaultIndex

private String defaultIndex(IndexFacts.Session indexFacts,
                            LegacyCombinator.QueryPart part)

addAndItem

private static void addAndItem(QueryTree queryTree,
                               Item item)

assignDefaultIndex

private static void assignDefaultIndex(Item item,
                                       String defaultIndex)

findQuerySnippets

private static Set<LegacyCombinator.QueryPart> findQuerySnippets(Properties properties)

hasDots

private static boolean hasDots(String name)