sirius.search.suggestion.Complete Maven / Gradle / Ivy
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/*
* Made with all the love in the world
* by scireum in Remshalden, Germany
*
* Copyright by scireum GmbH
* http://www.scireum.de - [email protected]
*/
package sirius.search.suggestion;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
import org.elasticsearch.search.suggest.completion.RegexOptions;
import sirius.search.Entity;
import sirius.search.IndexAccess;
import java.util.Collections;
import java.util.List;
import java.util.Map;
/**
* Represents a completion against the database which are created via {@link IndexAccess#complete(Class)}.
*
* A completion can ONLY be used on fields annotated with {@link sirius.search.annotations.NestedObject} and {@link
* sirius.search.annotations.FastCompletion}. This is necessary as elasticsearch internally builds a fast datastructure
* (FST) to allow fast completions.
*
* @param the type of entities for which a field should be completed
*/
public class Complete {
private IndexAccess index;
private Class clazz;
private String field;
private String query;
private int limit = 5;
private Map> contexts;
private Fuzziness fuzziness = Fuzziness.AUTO;
private boolean isRegexQuery = false;
private int maxDeterminizedStates = -1;
/**
* Creates a new completion for the given index access and entity type.
*
* @param index the instance of IndexAccess being used
* @param clazz the entity type to operate on
*/
public Complete(IndexAccess index, Class clazz) {
this.index = index;
this.clazz = clazz;
}
/**
* Defines the field which is used for completion
*
* @param field a field of type {@link AutoCompletion}
* @return a newly created completion helper
*/
public Complete on(String field) {
this.field = field;
return this;
}
/**
* Sets a regex as completion query.
*
* @param regex the query regex
* @return the completion helper itself for fluent method calls
*/
public Complete regex(String regex) {
this.query = regex;
this.isRegexQuery = true;
return this;
}
/**
* Sets the query to a prefix that must be matched.
*
* @param prefix the query prefix
* @return the completion helper itself for fluent method calls
*/
public Complete prefix(String prefix) {
this.query = prefix;
return this;
}
/**
* Limits the number of completions that are generated
*
* @param limit the maximum number of completions to generate
* @return the completion helper itself for fluent method calls
*/
public Complete limit(int limit) {
this.limit = limit;
return this;
}
/**
* Specifies the maximal number of determinized states.
*
* @param maxDeterminizedStates the maximal number of determinized states
* @return the completion helper itself for fluent method calls
*/
public Complete maxDeterminizedStates(int maxDeterminizedStates) {
this.maxDeterminizedStates = maxDeterminizedStates;
return this;
}
/**
* Allows to restrict/filter completions by adding context.
*
* @param contexts the contexts that should be applied
* @return the completion helper itself for fluent method calls
*/
public Complete contexts(Map> contexts) {
this.contexts = contexts;
return this;
}
/**
* Sets the fuzziness for the completer to compensate misspellings
*
* @param fuzziness defines the levenshtein distance
* @return the completion helper itself for fluent method calls
*/
public Complete fuzziness(Fuzziness fuzziness) {
this.fuzziness = fuzziness;
return this;
}
/**
* Executes available completion-options or an empty list otherwise
*
* @return the generated completions or an empty list
*/
public List completeList() {
SuggestBuilder csb = generateCompletionBuilder();
SearchRequestBuilder sqb = generateRequestBuilder(csb);
return execute(sqb);
}
private List execute(SearchRequestBuilder sqb) {
SearchResponse response = sqb.execute().actionGet();
CompletionSuggestion completionSuggestion = response.getSuggest().getSuggestion("completion");
if (completionSuggestion != null) {
List entryList = completionSuggestion.getEntries();
if (entryList != null && entryList.get(0) != null && entryList.get(0).getOptions() != null) {
return entryList.get(0).getOptions();
}
}
return Collections.emptyList();
}
private SearchRequestBuilder generateRequestBuilder(SuggestBuilder builder) {
return index.getClient()
.prepareSearch(index.getIndexName(index.getDescriptor(clazz).getIndex()))
.suggest(builder);
}
private SuggestBuilder generateCompletionBuilder() {
CompletionSuggestionBuilder builder = SuggestBuilders.completionSuggestion(field).size(limit);
if (isRegexQuery) {
RegexOptions.Builder regexOptionsBuilder = RegexOptions.builder();
if (maxDeterminizedStates != -1) {
regexOptionsBuilder.setMaxDeterminizedStates(maxDeterminizedStates);
}
builder.regex(query, regexOptionsBuilder.build());
} else {
builder.prefix(query, fuzziness);
}
if (contexts != null) {
builder.contexts(contexts);
}
return new SuggestBuilder().addSuggestion("completion", builder);
}
}