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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.search.query.rewrite.rewriters;
import java.io.*;
import java.util.*;
import java.util.logging.Logger;
import com.yahoo.component.annotation.Inject;
import com.yahoo.component.chain.dependencies.Provides;
import com.yahoo.search.query.rewrite.*;
import com.yahoo.search.*;
import com.yahoo.component.ComponentId;
import com.yahoo.filedistribution.fileacquirer.FileAcquirer;
import com.yahoo.search.query.rewrite.RewritesConfig;
/**
* This rewriter would add rewrites to name entities to boost precision<br>
* - FSA dict: [normalized original query]\t[rewrite 1]\t[rewrite 2]\t[etc]<br>
* - Features:<br>
* OriginalAsUnit flag: add proximity boosting to original query<br>
* RewritesAsUnitEquiv flag: add proximity boosted rewrites to original query<br>
* RewritesAsEquiv flag: add rewrites to original query<br>
*
* @author Karen Sze Wing Lee
*/
@Provides("NameRewriter")
public class NameRewriter extends QueryRewriteSearcher {
// Flag for skipping this rewriter if the query has been rewritten
private final boolean SKIP_REWRITER_IF_REWRITTEN = false;
// Name of the rewriter
public static final String REWRITER_NAME = "NameRewriter";
// Name entity expansion dictionary name
public static final String NAME_ENTITY_EXPAND_DICT = "NameEntityExpansion";
// Default Name entity expansion dictionary file name
public static final String NAME_ENTITY_EXPAND_DICT_FILENAME = "NameRewriter.fsa";
private Logger logger;
/**
* Constructor for NameRewriter<br>
* Load configs using default format
*/
@Inject
public NameRewriter(ComponentId id,
FileAcquirer fileAcquirer,
RewritesConfig config) {
super(id, fileAcquirer, config);
}
/**
* Constructor for NameRewriter unit test<br>
* Load configs using default format
*/
public NameRewriter(RewritesConfig config,
HashMap<String, File> fileList) {
super(config, fileList);
}
/**
* Instance creation time config loading besides FSA<br>
* Empty for this rewriter
*/
public boolean configure(FileAcquirer fileAcquirer,
RewritesConfig config,
HashMap<String, File> fileList) {
logger = Logger.getLogger(NameRewriter.class.getName());
return true;
}
/**
* Main logic of rewriter<br>
* - Retrieve rewrites from FSA dict<br>
* - rewrite query using features that are enabled by user
*/
public HashMap<String, Object> rewrite(Query query,
String dictKey) throws RuntimeException {
Boolean rewritten = false;
// Pass the original dict key to the next rewriter
HashMap<String, Object> result = new HashMap<>();
result.put(RewriterConstants.REWRITTEN, rewritten);
result.put(RewriterConstants.DICT_KEY, dictKey);
RewriterUtils.log(logger, query,
"In NameRewriter, query used for dict retrieval=[" + dictKey + "]");
// Retrieve rewrite from FSA dict using normalized query
String rewrites = super.getRewriteFromFSA(query, NAME_ENTITY_EXPAND_DICT, dictKey);
RewriterUtils.log(logger, query, "Retrieved rewrites: " + rewrites);
// No rewrites
if(rewrites==null) {
RewriterUtils.log(logger, query, "No rewrite is retrieved");
return result;
}
// Retrieve max number of rewrites allowed
int maxNumRewrites = 0;
String maxNumRewritesStr = getQPConfig(query, RewriterConstants.MAX_REWRITES);
if(maxNumRewritesStr!=null) {
maxNumRewrites = Integer.parseInt(maxNumRewritesStr);
RewriterUtils.log(logger, query,
"Limiting max number of rewrites to: " + maxNumRewrites);
} else {
RewriterUtils.log(logger, query, "No limit on number of rewrites");
}
// Retrieve flags for enabling the features
String originalAsUnit = getQPConfig(query, RewriterConstants.ORIGINAL_AS_UNIT);
String originalAsUnitEquiv = getQPConfig(query, RewriterConstants.ORIGINAL_AS_UNIT_EQUIV);
String rewritesAsUnitEquiv = getQPConfig(query, RewriterConstants.REWRITES_AS_UNIT_EQUIV);
String rewritesAsEquiv = getQPConfig(query, RewriterConstants.REWRITES_AS_EQUIV);
// Add proximity boosting to original query and keeping
// the original query if it's enabled
if(originalAsUnitEquiv!=null && originalAsUnitEquiv.equalsIgnoreCase("true")) {
RewriterUtils.log(logger, query, "OriginalAsUnitEquiv is enabled");
query = RewriterFeatures.addUnitToOriginalQuery(query, dictKey, true);
RewriterUtils.log(logger, query,
"Query after OriginalAsUnitEquiv: " + query.toDetailString());
rewritten = true;
// Add proximity boosting to original query
// if it's enabled
} else if(originalAsUnit!=null && originalAsUnit.equalsIgnoreCase("true")) {
RewriterUtils.log(logger, query, "OriginalAsUnit is enabled");
query = RewriterFeatures.addUnitToOriginalQuery(query, dictKey, false);
RewriterUtils.log(logger, query,
"Query after OriginalAsUnit: " + query.toDetailString());
rewritten = true;
}
// Add rewrites as unit equiv if it's enabled
if(rewritesAsUnitEquiv!=null && rewritesAsUnitEquiv.equalsIgnoreCase("true")) {
RewriterUtils.log(logger, query, "RewritesAsUnitEquiv is enabled");
//query = RewriterFeatures.addRewritesAsEquiv(query, dictKey, rewrites, true, maxNumRewrites);
query = RewriterFeatures.addRewritesAsEquiv(query, dictKey, rewrites, true, maxNumRewrites);
RewriterUtils.log(logger, query,
"Query after RewritesAsUnitEquiv: " + query.toDetailString());
rewritten = true;
// Add rewrites as equiv if it's enabled
} else if(rewritesAsEquiv!=null && rewritesAsEquiv.equalsIgnoreCase("true")) {
RewriterUtils.log(logger, query, "RewritesAsEquiv is enabled");
//query = RewriterFeatures.addRewritesAsEquiv(query, dictKey, rewrites, false, maxNumRewrites);
query = RewriterFeatures.addRewritesAsEquiv(query, dictKey, rewrites, false, maxNumRewrites);
RewriterUtils.log(logger, query,
"Query after RewritesAsEquiv: " + query.toDetailString());
rewritten = true;
}
RewriterUtils.log(logger, query, "NameRewriter final query: " + query.toDetailString());
result.put(RewriterConstants.REWRITTEN, rewritten);
return result;
}
/**
* Get the flag which specifies whether this rewriter.
* should be skipped if the query has been rewritten
*
* @return true if rewriter should be skipped, false
* otherwise
*/
public boolean getSkipRewriterIfRewritten() {
return SKIP_REWRITER_IF_REWRITTEN;
}
/**
* Get the name of the rewriter
*
* @return Name of the rewriter
*/
public String getRewriterName() {
return REWRITER_NAME;
}
/**
* Get default FSA dictionary names
*
* @return Pair of FSA dictionary name and filename
*/
public HashMap<String, String> getDefaultFSAs() {
HashMap<String, String> defaultDicts = new HashMap<>();
defaultDicts.put(NAME_ENTITY_EXPAND_DICT, NAME_ENTITY_EXPAND_DICT_FILENAME);
return defaultDicts;
}
}
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