fix #2751 add rank fusion

src/main/java/org/codelibs/fess/api/json/SearchApiManager.java

@@ -848,6 +848,8 @@ public class SearchApiManager extends BaseApiManager {
 
         private int startPosition = -1;
 
+        private int offset = -1;
+
         private int pageSize = -1;
 
         protected JsonRequestParams(final HttpServletRequest request, final FessConfig fessConfig) {
@@ -935,6 +937,25 @@ public class SearchApiManager extends BaseApiManager {
             return startPosition;
         }
 
+        @Override
+        public int getOffset() {
+            if (offset != -1) {
+                return offset;
+            }
+
+            final String value = request.getParameter("offset");
+            if (StringUtil.isBlank(value)) {
+                offset = 0;
+            } else {
+                try {
+                    offset = Integer.parseInt(value);
+                } catch (final NumberFormatException e) {
+                    offset = 0;
+                }
+            }
+            return offset;
+        }
+
         @Override
         public int getPageSize() {
             if (pageSize != -1) {
@@ -1071,6 +1092,11 @@ public class SearchApiManager extends BaseApiManager {
             throw new UnsupportedOperationException();
         }
 
+        @Override
+        public int getOffset() {
+            throw new UnsupportedOperationException();
+        }
+
         @Override
         public int getPageSize() {
             throw new UnsupportedOperationException();

src/main/java/org/codelibs/fess/app/web/admin/searchlist/ListForm.java

@@ -47,6 +47,9 @@ public class ListForm extends SearchRequestParams {
     @ValidateTypeFailure
     public Integer start;
 
+    @ValidateTypeFailure
+    public Integer offset;
+
     @ValidateTypeFailure
     public Integer pn;
 
@@ -91,6 +94,14 @@ public class ListForm extends SearchRequestParams {
         return start;
     }
 
+    @Override
+    public int getOffset() {
+        if (offset == null) {
+            offset = 0;
+        }
+        return offset;
+    }
+
     @Override
     public int getPageSize() {
         final FessConfig fessConfig = ComponentUtil.getFessConfig();

src/main/java/org/codelibs/fess/app/web/base/SearchForm.java

@@ -55,6 +55,9 @@ public class SearchForm extends SearchRequestParams {
     @ValidateTypeFailure
     public Integer start;
 
+    @ValidateTypeFailure
+    public Integer offset;
+
     @ValidateTypeFailure
     public Integer pn;
 
@@ -68,13 +71,20 @@ public class SearchForm extends SearchRequestParams {
 
     @Override
     public int getStartPosition() {
-        final FessConfig fessConfig = ComponentUtil.getFessConfig();
         if (start == null) {
-            start = fessConfig.getPagingSearchPageStartAsInteger();
+            start = ComponentUtil.getFessConfig().getPagingSearchPageStartAsInteger();
         }
         return start;
     }
 
+    @Override
+    public int getOffset() {
+        if (offset == null) {
+            offset = 0;
+        }
+        return offset;
+    }
+
     @Override
     public int getPageSize() {
         final FessConfig fessConfig = ComponentUtil.getFessConfig();

src/main/java/org/codelibs/fess/entity/GeoInfo.java

@@ -15,8 +15,6 @@
  */
 package org.codelibs.fess.entity;
 
-import static org.codelibs.core.stream.StreamUtil.stream;
-
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -25,6 +23,7 @@ import java.util.Map;
 import javax.servlet.http.HttpServletRequest;
 
 import org.codelibs.core.lang.StringUtil;
+import org.codelibs.core.stream.StreamUtil;
 import org.codelibs.fess.exception.InvalidQueryException;
 import org.codelibs.fess.mylasta.direction.FessConfig;
 import org.codelibs.fess.util.ComponentUtil;
@@ -43,7 +42,7 @@ public class GeoInfo {
         final String[] geoFields = fessConfig.getQueryGeoFieldsAsArray();
         final Map<String, List<QueryBuilder>> geoMap = new HashMap<>();
 
-        stream(request.getParameterMap())
+        StreamUtil.stream(request.getParameterMap())
                 .of(stream -> stream.filter(e -> e.getKey().startsWith("geo.") && e.getKey().endsWith(".point")).forEach(e -> {
                     final String key = e.getKey();
                     for (final String geoField : geoFields) {
@@ -51,7 +50,7 @@ public class GeoInfo {
                             final String distanceKey = key.replaceFirst(".point$", ".distance");
                             final String distance = request.getParameter(distanceKey);
                             if (StringUtil.isNotBlank(distance)) {
-                                stream(e.getValue()).of(s -> s.forEach(pt -> {
+                                StreamUtil.stream(e.getValue()).of(s -> s.forEach(pt -> {
                                     List<QueryBuilder> list = geoMap.get(geoField);
                                     if (list == null) {
                                         list = new ArrayList<>();
@@ -95,7 +94,7 @@ public class GeoInfo {
             builder = queryBuilders[0];
         } else if (queryBuilders.length > 1) {
             final BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
-            stream(queryBuilders).of(stream -> stream.forEach(boolQuery::must));
+            StreamUtil.stream(queryBuilders).of(stream -> stream.forEach(boolQuery::must));
             builder = boolQuery;
         }
 

src/main/java/org/codelibs/fess/entity/SearchRequestParams.java

@@ -63,6 +63,8 @@ public abstract class SearchRequestParams {
 
     public abstract int getPageSize();
 
+    public abstract int getOffset();
+
     public abstract String[] getExtraQueries();
 
     public abstract Object getAttribute(String name);

src/main/java/org/codelibs/fess/es/client/SearchEngineClient.java

@@ -18,6 +18,7 @@ package org.codelibs.fess.es.client;
 import static org.codelibs.core.stream.StreamUtil.split;
 import static org.codelibs.core.stream.StreamUtil.stream;
 import static org.codelibs.opensearch.runner.OpenSearchRunner.newConfigs;
+import static org.opensearch.action.ActionListener.wrap;
 
 import java.io.File;
 import java.io.IOException;
@@ -918,7 +919,7 @@ public class SearchEngineClient implements Client {
     protected void deleteScrollContext(final String scrollId) {
         if (scrollId != null) {
             client.prepareClearScroll().addScrollId(scrollId)
-                    .execute(ActionListener.wrap(res -> {}, e -> logger.warn("Failed to clear the scroll context.", e)));
+                    .execute(wrap(res -> {}, e -> logger.warn("Failed to clear the scroll context.", e)));
         }
     }
 

src/main/java/org/codelibs/fess/helper/SearchHelper.java

@@ -159,33 +159,7 @@ public class SearchHelper {
 
     protected List<Map<String, Object>> searchInternal(final String query, final SearchRequestParams params,
             final OptionalThing<FessUserBean> userBean) {
-        final FessConfig fessConfig = ComponentUtil.getFessConfig();
-        final QueryHelper queryHelper = ComponentUtil.getQueryHelper();
-        final int pageSize = params.getPageSize();
-        LaRequestUtil.getOptionalRequest().ifPresent(request -> {
-            request.setAttribute(Constants.REQUEST_PAGE_SIZE, pageSize);
-        });
-        return ComponentUtil.getSearchEngineClient().search(fessConfig.getIndexDocumentSearchIndex(), searchRequestBuilder -> {
-            queryHelper.processSearchPreference(searchRequestBuilder, userBean, query);
-            return SearchConditionBuilder.builder(searchRequestBuilder).query(query).offset(params.getStartPosition()).size(pageSize)
-                    .facetInfo(params.getFacetInfo()).geoInfo(params.getGeoInfo()).highlightInfo(params.getHighlightInfo())
-                    .similarDocHash(params.getSimilarDocHash()).responseFields(params.getResponseFields())
-                    .searchRequestType(params.getType()).trackTotalHits(params.getTrackTotalHits()).build();
-        }, (searchRequestBuilder, execTime, searchResponse) -> {
-            searchResponse.ifPresent(r -> {
-                if (r.getTotalShards() != r.getSuccessfulShards() && fessConfig.isQueryTimeoutLogging()) {
-                    // partial results
-                    final StringBuilder buf = new StringBuilder(1000);
-                    buf.append("[SEARCH TIMEOUT] {\"exec_time\":").append(execTime)//
-                            .append(",\"request\":").append(searchRequestBuilder.toString())//
-                            .append(",\"response\":").append(r.toString()).append('}');
-                    logger.warn(buf.toString());
-                }
-            });
-            final QueryResponseList queryResponseList = ComponentUtil.getQueryResponseList();
-            queryResponseList.init(searchResponse, params.getStartPosition(), params.getPageSize());
-            return queryResponseList;
-        });
+        return ComponentUtil.getRankFusionProcessor().search(query, params, userBean);
     }
 
     public long scrollSearch(final SearchRequestParams params, final BooleanFunction<Map<String, Object>> cursor,

src/main/java/org/codelibs/fess/mylasta/direction/FessConfig.java

@@ -1140,6 +1140,18 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
      *  */
     String QUERY_FACET_QUERIES = "query.facet.queries";
 
+    /** The key of the configuration. e.g. 200 */
+    String RANK_FUSION_window_size = "rank.fusion.window_size";
+
+    /** The key of the configuration. e.g. 20 */
+    String RANK_FUSION_rank_constant = "rank.fusion.rank_constant";
+
+    /** The key of the configuration. e.g. -1 */
+    String RANK_FUSION_THREADS = "rank.fusion.threads";
+
+    /** The key of the configuration. e.g. rf_score */
+    String RANK_FUSION_score_field = "rank.fusion.score_field";
+
     /** The key of the configuration. e.g. true */
     String SMB_ROLE_FROM_FILE = "smb.role.from.file";
 
@@ -5345,6 +5357,60 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
      */
     String getQueryFacetQueries();
 
+    /**
+     * Get the value for the key 'rank.fusion.window_size'. <br>
+     * The value is, e.g. 200 <br>
+     * comment: ranking
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     */
+    String getRankFusionWindowSize();
+
+    /**
+     * Get the value for the key 'rank.fusion.window_size' as {@link Integer}. <br>
+     * The value is, e.g. 200 <br>
+     * comment: ranking
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     * @throws NumberFormatException When the property is not integer.
+     */
+    Integer getRankFusionWindowSizeAsInteger();
+
+    /**
+     * Get the value for the key 'rank.fusion.rank_constant'. <br>
+     * The value is, e.g. 20 <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     */
+    String getRankFusionRankConstant();
+
+    /**
+     * Get the value for the key 'rank.fusion.rank_constant' as {@link Integer}. <br>
+     * The value is, e.g. 20 <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     * @throws NumberFormatException When the property is not integer.
+     */
+    Integer getRankFusionRankConstantAsInteger();
+
+    /**
+     * Get the value for the key 'rank.fusion.threads'. <br>
+     * The value is, e.g. -1 <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     */
+    String getRankFusionThreads();
+
+    /**
+     * Get the value for the key 'rank.fusion.threads' as {@link Integer}. <br>
+     * The value is, e.g. -1 <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     * @throws NumberFormatException When the property is not integer.
+     */
+    Integer getRankFusionThreadsAsInteger();
+
+    /**
+     * Get the value for the key 'rank.fusion.score_field'. <br>
+     * The value is, e.g. rf_score <br>
+     * @return The value of found property. (NotNull: if not found, exception but basically no way)
+     */
+    String getRankFusionScoreField();
+
     /**
      * Get the value for the key 'smb.role.from.file'. <br>
      * The value is, e.g. true <br>
@@ -9448,6 +9514,34 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
             return get(FessConfig.QUERY_FACET_QUERIES);
         }
 
+        public String getRankFusionWindowSize() {
+            return get(FessConfig.RANK_FUSION_window_size);
+        }
+
+        public Integer getRankFusionWindowSizeAsInteger() {
+            return getAsInteger(FessConfig.RANK_FUSION_window_size);
+        }
+
+        public String getRankFusionRankConstant() {
+            return get(FessConfig.RANK_FUSION_rank_constant);
+        }
+
+        public Integer getRankFusionRankConstantAsInteger() {
+            return getAsInteger(FessConfig.RANK_FUSION_rank_constant);
+        }
+
+        public String getRankFusionThreads() {
+            return get(FessConfig.RANK_FUSION_THREADS);
+        }
+
+        public Integer getRankFusionThreadsAsInteger() {
+            return getAsInteger(FessConfig.RANK_FUSION_THREADS);
+        }
+
+        public String getRankFusionScoreField() {
+            return get(FessConfig.RANK_FUSION_score_field);
+        }
+
         public String getSmbRoleFromFile() {
             return get(FessConfig.SMB_ROLE_FROM_FILE);
         }
@@ -11019,6 +11113,10 @@ public interface FessConfig extends FessEnv, org.codelibs.fess.mylasta.direction
             defaultMap.put(FessConfig.QUERY_FACET_FIELDS_MISSING, "");
             defaultMap.put(FessConfig.QUERY_FACET_QUERIES,
                     "labels.facet_timestamp_title:labels.facet_timestamp_1day=timestamp:[now/d-1d TO *]\tlabels.facet_timestamp_1week=timestamp:[now/d-7d TO *]\tlabels.facet_timestamp_1month=timestamp:[now/d-1M TO *]\tlabels.facet_timestamp_1year=timestamp:[now/d-1y TO *]\nlabels.facet_contentLength_title:labels.facet_contentLength_10k=content_length:[0 TO 9999]\tlabels.facet_contentLength_10kto100k=content_length:[10000 TO 99999]\tlabels.facet_contentLength_100kto500k=content_length:[100000 TO 499999]\tlabels.facet_contentLength_500kto1m=content_length:[500000 TO 999999]\tlabels.facet_contentLength_1m=content_length:[1000000 TO *]\nlabels.facet_filetype_title:labels.facet_filetype_html=filetype:html\tlabels.facet_filetype_word=filetype:word\tlabels.facet_filetype_excel=filetype:excel\tlabels.facet_filetype_powerpoint=filetype:powerpoint\tlabels.facet_filetype_odt=filetype:odt\tlabels.facet_filetype_ods=filetype:ods\tlabels.facet_filetype_odp=filetype:odp\tlabels.facet_filetype_pdf=filetype:pdf\tlabels.facet_filetype_txt=filetype:txt\tlabels.facet_filetype_others=filetype:others\n");
+            defaultMap.put(FessConfig.RANK_FUSION_window_size, "200");
+            defaultMap.put(FessConfig.RANK_FUSION_rank_constant, "20");
+            defaultMap.put(FessConfig.RANK_FUSION_THREADS, "-1");
+            defaultMap.put(FessConfig.RANK_FUSION_score_field, "rf_score");
             defaultMap.put(FessConfig.SMB_ROLE_FROM_FILE, "true");
             defaultMap.put(FessConfig.SMB_AVAILABLE_SID_TYPES, "1,2,4:2,5:1");
             defaultMap.put(FessConfig.FILE_ROLE_FROM_FILE, "true");

src/main/java/org/codelibs/fess/rank/fusion/DefaultSearcher.java

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2012-2023 CodeLibs Project and the Others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+package org.codelibs.fess.rank.fusion;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.codelibs.core.stream.StreamUtil;
+import org.codelibs.fess.Constants;
+import org.codelibs.fess.entity.SearchRequestParams;
+import org.codelibs.fess.es.client.SearchEngineClient.SearchConditionBuilder;
+import org.codelibs.fess.helper.ViewHelper;
+import org.codelibs.fess.mylasta.action.FessUserBean;
+import org.codelibs.fess.mylasta.direction.FessConfig;
+import org.codelibs.fess.rank.fusion.SearchResult.SearchResultBuilder;
+import org.codelibs.fess.util.ComponentUtil;
+import org.codelibs.fess.util.FacetResponse;
+import org.dbflute.optional.OptionalEntity;
+import org.dbflute.optional.OptionalThing;
+import org.lastaflute.web.util.LaRequestUtil;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.common.document.DocumentField;
+import org.opensearch.search.SearchHit;
+import org.opensearch.search.SearchHits;
+import org.opensearch.search.aggregations.Aggregations;
+import org.opensearch.search.fetch.subphase.highlight.HighlightField;
+
+public class DefaultSearcher extends RankFusionSearcher {
+
+    private static final Logger logger = LogManager.getLogger(DefaultSearcher.class);
+
+    @Override
+    protected SearchResult search(final String query, final SearchRequestParams params, final OptionalThing<FessUserBean> userBean) {
+        final int pageSize = params.getPageSize();
+        LaRequestUtil.getOptionalRequest().ifPresent(request -> {
+            request.setAttribute(Constants.REQUEST_PAGE_SIZE, pageSize);
+        });
+        final OptionalEntity<SearchResponse> searchResponseOpt = sendRequest(query, params, userBean);
+        return processResponse(searchResponseOpt);
+    }
+
+    protected SearchResult processResponse(final OptionalEntity<SearchResponse> searchResponseOpt) {
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        final SearchResultBuilder builder = SearchResult.create();
+        searchResponseOpt.ifPresent(searchResponse -> {
+            final SearchHits searchHits = searchResponse.getHits();
+            builder.allRecordCount(searchHits.getTotalHits().value);
+            builder.allRecordCountRelation(searchHits.getTotalHits().relation.toString());
+            builder.queryTime(searchResponse.getTook().millis());
+
+            if (searchResponse.getTotalShards() != searchResponse.getSuccessfulShards()) {
+                builder.partialResults(true);
+            }
+
+            // build highlighting fields
+            final String hlPrefix = ComponentUtil.getQueryHelper().getHighlightPrefix();
+            for (final SearchHit searchHit : searchHits.getHits()) {
+                final Map<String, Object> docMap = parseSearchHit(fessConfig, hlPrefix, searchHit);
+
+                if (fessConfig.isResultCollapsed()) {
+                    final Map<String, SearchHits> innerHits = searchHit.getInnerHits();
+                    if (innerHits != null) {
+                        final SearchHits innerSearchHits = innerHits.get(fessConfig.getQueryCollapseInnerHitsName());
+                        if (innerSearchHits != null) {
+                            final long totalHits = innerSearchHits.getTotalHits().value;
+                            if (totalHits > 1) {
+                                docMap.put(fessConfig.getQueryCollapseInnerHitsName() + "_count", totalHits);
+                                final DocumentField bitsField = searchHit.getFields().get(fessConfig.getIndexFieldContentMinhashBits());
+                                if (bitsField != null && !bitsField.getValues().isEmpty()) {
+                                    docMap.put(fessConfig.getQueryCollapseInnerHitsName() + "_hash", bitsField.getValues().get(0));
+                                }
+                                docMap.put(fessConfig.getQueryCollapseInnerHitsName(), StreamUtil.stream(innerSearchHits.getHits())
+                                        .get(stream -> stream.map(v -> parseSearchHit(fessConfig, hlPrefix, v)).toArray(n -> new Map[n])));
+                            }
+                        }
+                    }
+                }
+
+                builder.addDocument(docMap);
+            }
+
+            // facet
+            final Aggregations aggregations = searchResponse.getAggregations();
+            if (aggregations != null) {
+                builder.facetResponse(new FacetResponse(aggregations));
+            }
+
+        });
+        return builder.build();
+    }
+
+    protected OptionalEntity<SearchResponse> sendRequest(final String query, final SearchRequestParams params,
+            final OptionalThing<FessUserBean> userBean) {
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        final int pageSize = params.getPageSize();
+        return ComponentUtil.getSearchEngineClient().search(fessConfig.getIndexDocumentSearchIndex(), searchRequestBuilder -> {
+            ComponentUtil.getQueryHelper().processSearchPreference(searchRequestBuilder, userBean, query);
+            return SearchConditionBuilder.builder(searchRequestBuilder).query(query).offset(params.getStartPosition()).size(pageSize)
+                    .facetInfo(params.getFacetInfo()).geoInfo(params.getGeoInfo()).highlightInfo(params.getHighlightInfo())
+                    .similarDocHash(params.getSimilarDocHash()).responseFields(params.getResponseFields())
+                    .searchRequestType(params.getType()).trackTotalHits(params.getTrackTotalHits()).build();
+        }, (searchRequestBuilder, execTime, searchResponse) -> {
+            searchResponse.ifPresent(r -> {
+                if (r.getTotalShards() != r.getSuccessfulShards() && fessConfig.isQueryTimeoutLogging()) {
+                    // partial results
+                    final StringBuilder buf = new StringBuilder(1000);
+                    buf.append("[SEARCH TIMEOUT] {\"exec_time\":").append(execTime)//
+                            .append(",\"request\":").append(searchRequestBuilder.toString())//
+                            .append(",\"response\":").append(r.toString()).append('}');
+                    logger.warn(buf.toString());
+                }
+            });
+            return searchResponse;
+        });
+    }
+
+    protected Map<String, Object> parseSearchHit(final FessConfig fessConfig, final String hlPrefix, final SearchHit searchHit) {
+        final Map<String, Object> docMap = new HashMap<>(32);
+        if (searchHit.getSourceAsMap() == null) {
+            searchHit.getFields().forEach((key, value) -> {
+                docMap.put(key, value.getValue());
+            });
+        } else {
+            docMap.putAll(searchHit.getSourceAsMap());
+        }
+
+        final ViewHelper viewHelper = ComponentUtil.getViewHelper();
+
+        final Map<String, HighlightField> highlightFields = searchHit.getHighlightFields();
+        try {
+            if (highlightFields != null) {
+                highlightFields.values().stream().forEach(highlightField -> {
+                    final String text = viewHelper.createHighlightText(highlightField);
+                    if (text != null) {
+                        docMap.put(hlPrefix + highlightField.getName(), text);
+                    }
+                });
+                if (Constants.TEXT_FRAGMENT_TYPE_HIGHLIGHT.equals(fessConfig.getQueryHighlightTextFragmentType())) {
+                    docMap.put(Constants.TEXT_FRAGMENTS,
+                            viewHelper.createTextFragmentsByHighlight(highlightFields.values().toArray(n -> new HighlightField[n])));
+                }
+            }
+        } catch (final Exception e) {
+            if (logger.isDebugEnabled()) {
+                logger.debug("Could not create a highlighting value: {}", docMap, e);
+            }
+        }
+
+        if (Constants.TEXT_FRAGMENT_TYPE_QUERY.equals(fessConfig.getQueryHighlightTextFragmentType())) {
+            docMap.put(Constants.TEXT_FRAGMENTS, viewHelper.createTextFragmentsByQuery());
+        }
+
+        // ContentTitle
+        if (viewHelper != null) {
+            docMap.put(fessConfig.getResponseFieldContentTitle(), viewHelper.getContentTitle(docMap));
+            docMap.put(fessConfig.getResponseFieldContentDescription(), viewHelper.getContentDescription(docMap));
+            docMap.put(fessConfig.getResponseFieldUrlLink(), viewHelper.getUrlLink(docMap));
+            docMap.put(fessConfig.getResponseFieldSitePath(), viewHelper.getSitePath(docMap));
+        }
+
+        if (!docMap.containsKey(Constants.SCORE)) {
+            docMap.put(Constants.SCORE, searchHit.getScore());
+        }
+
+        if (!docMap.containsKey(fessConfig.getIndexFieldId())) {
+            docMap.put(fessConfig.getIndexFieldId(), searchHit.getId());
+        }
+        return docMap;
+    }
+
+}

src/main/java/org/codelibs/fess/rank/fusion/RankFusionProcessor.java

@@ -0,0 +1,311 @@
+/*
+ * Copyright 2012-2023 CodeLibs Project and the Others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+package org.codelibs.fess.rank.fusion;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.lucene.search.TotalHits.Relation;
+import org.codelibs.fess.entity.FacetInfo;
+import org.codelibs.fess.entity.GeoInfo;
+import org.codelibs.fess.entity.HighlightInfo;
+import org.codelibs.fess.entity.SearchRequestParams;
+import org.codelibs.fess.mylasta.action.FessUserBean;
+import org.codelibs.fess.mylasta.direction.FessConfig;
+import org.codelibs.fess.util.ComponentUtil;
+import org.codelibs.fess.util.QueryResponseList;
+import org.dbflute.optional.OptionalThing;
+
+public class RankFusionProcessor implements AutoCloseable {
+
+    private static final Logger logger = LogManager.getLogger(RankFusionProcessor.class);
+
+    protected RankFusionSearcher[] searchers = new RankFusionSearcher[1];
+
+    protected ExecutorService executorService;
+
+    protected int windowSize;
+
+    @PostConstruct
+    public void init() {
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        final int maxPageSize = fessConfig.getPagingSearchPageMaxSizeAsInteger();
+        final int windowSize = fessConfig.getRankFusionWindowSizeAsInteger();
+        if (maxPageSize * 2 < windowSize) {
+            logger.warn("rank.fusion.window_size is lower than paging.search.page.max.size. "
+                    + "The window size should be 2x more than the page size. ({} * 2 <= {})", maxPageSize, windowSize);
+            this.windowSize = 2 * maxPageSize;
+        } else {
+            this.windowSize = windowSize;
+        }
+    }
+
+    @PreDestroy
+    public void close() throws Exception {
+        if (executorService != null) {
+            try {
+                executorService.shutdown();
+                executorService.awaitTermination(60, TimeUnit.SECONDS);
+            } catch (final InterruptedException e) {
+                if (logger.isDebugEnabled()) {
+                    logger.debug("Interrupted.", e);
+                }
+            } finally {
+                executorService.shutdownNow();
+            }
+        }
+    }
+
+    public List<Map<String, Object>> search(final String query, final SearchRequestParams params,
+            final OptionalThing<FessUserBean> userBean) {
+        final int pageSize = params.getPageSize();
+        if (searchers.length == 1) {
+            final SearchResult searchResult = searchers[0].search(query, params, userBean);
+            return new QueryResponseList(searchResult.getDocumentList(), searchResult.getAllRecordCount(),
+                    searchResult.getAllRecordCountRelation(), searchResult.getQueryTime(), searchResult.isPartialResults(),
+                    searchResult.getFacetResponse(), params.getStartPosition(), pageSize, 0);
+        }
+
+        final int startPosition = params.getStartPosition();
+        if (startPosition * 2 >= windowSize) {
+            int offset = params.getOffset();
+            if (offset < 0) {
+                offset = 0;
+            } else if (offset > windowSize / 2) {
+                offset = windowSize / 2;
+            }
+            int start = startPosition - offset;
+            if (start < 0) {
+                start = 0;
+            }
+            final SearchRequestParams reqParams = new SearchRequestParamsWrapper(params, start, pageSize);
+            final SearchResult searchResult = searchers[0].search(query, reqParams, userBean);
+            long allRecordCount = searchResult.getAllRecordCount();
+            if (Relation.EQUAL_TO.toString().equals(searchResult.getAllRecordCountRelation())) {
+                allRecordCount += offset;
+            }
+            return new QueryResponseList(searchResult.getDocumentList(), allRecordCount, searchResult.getAllRecordCountRelation(),
+                    searchResult.getQueryTime(), searchResult.isPartialResults(), searchResult.getFacetResponse(),
+                    params.getStartPosition(), pageSize, offset);
+        }
+
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        final int rankConstant = fessConfig.getRankFusionRankConstantAsInteger();
+        final int size = windowSize / searchers.length;
+        final List<Future<SearchResult>> resultList = new ArrayList<>();
+        for (int i = 0; i < searchers.length; i++) {
+            final SearchRequestParams reqParams = new SearchRequestParamsWrapper(params, 0, i == 0 ? windowSize : size);
+            final RankFusionSearcher searcher = searchers[i];
+            resultList.add(executorService.submit(() -> searcher.search(query, reqParams, userBean)));
+        }
+        final SearchResult[] results = resultList.stream().map(f -> {
+            try {
+                return f.get();
+            } catch (InterruptedException | ExecutionException e) {
+                if (logger.isDebugEnabled()) {
+                    logger.debug("Failed to process a search result.", e);
+                }
+                return SearchResult.create().build();
+            }
+        }).toArray(n -> new SearchResult[n]);
+
+        final String scoreField = fessConfig.getRankFusionScoreField();
+        final Map<String, Map<String, Object>> scoreDocMap = new HashMap<>();
+        final String idField = fessConfig.getIndexFieldId();
+        final Set<Object> mainIdSet = new HashSet<>();
+        for (int i = 0; i < results.length; i++) {
+            final List<Map<String, Object>> docList = results[i].getDocumentList();
+            for (int j = 0; j < docList.size(); j++) {
+                final Map<String, Object> doc = docList.get(j);
+                if (doc.get(idField) instanceof final String id) {
+                    final float score = 1.0f / (rankConstant + j);
+                    if (scoreDocMap.containsKey(id)) {
+                        Map<String, Object> baseDoc = scoreDocMap.get(id);
+                        float oldScore = toFloat(baseDoc.get(scoreField));
+                        baseDoc.put(scoreField, oldScore + score);
+                    } else {
+                        doc.put(scoreField, Float.valueOf(score));
+                        scoreDocMap.put(id, doc);
+                    }
+                    if (i == 0 && j < windowSize / 2) {
+                        mainIdSet.add(id);
+                    }
+                }
+            }
+        }
+
+        final var docs = scoreDocMap.values().stream()
+                .sorted((e1, e2) -> Float.compare(toFloat(e2.get(scoreField)), toFloat(e1.get(scoreField)))).toList();
+        int offset = 0;
+        for (int i = 0; i < windowSize / 2; i++) {
+            if (!mainIdSet.contains(docs.get(i).get(idField))) {
+                offset++;
+            }
+        }
+        final SearchResult mainResult = results[0];
+        long allRecordCount = mainResult.getAllRecordCount();
+        if (Relation.EQUAL_TO.toString().equals(mainResult.getAllRecordCountRelation())) {
+            allRecordCount += offset;
+        }
+        return new QueryResponseList(docs.subList(startPosition, startPosition + pageSize), allRecordCount,
+                mainResult.getAllRecordCountRelation(), mainResult.getQueryTime(), mainResult.isPartialResults(),
+                mainResult.getFacetResponse(), startPosition, pageSize, offset);
+    }
+
+    protected float toFloat(final Object value) {
+        if (value instanceof final Float f) {
+            return f;
+        }
+        if (value instanceof final String s) {
+            return Float.parseFloat(s);
+        }
+        return 0.0f;
+    }
+
+    protected static class SearchRequestParamsWrapper extends SearchRequestParams {
+        private final SearchRequestParams parent;
+        private final int startPosition;
+        private final int pageSize;
+
+        SearchRequestParamsWrapper(final SearchRequestParams parent, final int startPosition, final int pageSize) {
+            this.parent = parent;
+            this.startPosition = startPosition;
+            this.pageSize = pageSize;
+        }
+
+        public SearchRequestParams getParent() {
+            return parent;
+        }
+
+        @Override
+        public String getQuery() {
+            return parent.getQuery();
+        }
+
+        @Override
+        public Map<String, String[]> getFields() {
+            return parent.getFields();
+        }
+
+        @Override
+        public Map<String, String[]> getConditions() {
+            return parent.getConditions();
+        }
+
+        @Override
+        public String[] getLanguages() {
+            return parent.getLanguages();
+        }
+
+        @Override
+        public GeoInfo getGeoInfo() {
+            return parent.getGeoInfo();
+        }
+
+        @Override
+        public FacetInfo getFacetInfo() {
+            return parent.getFacetInfo();
+        }
+
+        @Override
+        public HighlightInfo getHighlightInfo() {
+            return parent.getHighlightInfo();
+        }
+
+        @Override
+        public String getSort() {
+            return parent.getSort();
+        }
+
+        @Override
+        public int getStartPosition() {
+            return startPosition;
+        }
+
+        @Override
+        public int getOffset() {
+            return 0;
+        }
+
+        @Override
+        public int getPageSize() {
+            return pageSize;
+        }
+
+        @Override
+        public String[] getExtraQueries() {
+            return parent.getExtraQueries();
+        }
+
+        @Override
+        public Object getAttribute(final String name) {
+            return parent.getAttribute(name);
+        }
+
+        @Override
+        public Locale getLocale() {
+            return parent.getLocale();
+        }
+
+        @Override
+        public SearchRequestType getType() {
+            return parent.getType();
+        }
+
+        @Override
+        public String getSimilarDocHash() {
+            return parent.getSimilarDocHash();
+        }
+    }
+
+    public void setSeacher(final RankFusionSearcher searcher) {
+        this.searchers[0] = searcher;
+    }
+
+    public void register(final RankFusionSearcher searcher) {
+        if (logger.isDebugEnabled()) {
+            logger.debug("Load {}", searcher.getClass().getSimpleName());
+        }
+        final RankFusionSearcher[] newSearchers = Arrays.copyOf(searchers, searchers.length + 1);
+        newSearchers[newSearchers.length - 1] = searcher;
+        searchers = newSearchers;
+        synchronized (this) {
+            if (executorService == null) {
+                int numThreads = ComponentUtil.getFessConfig().getRankFusionThreadsAsInteger();
+                if (numThreads <= 0) {
+                    numThreads = (Runtime.getRuntime().availableProcessors() * 3) / 2 + 1;
+                }
+                executorService = Executors.newFixedThreadPool(numThreads);
+            }
+        }
+    }
+}

src/main/java/org/codelibs/fess/rank/fusion/RankFusionSearcher.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2012-2023 CodeLibs Project and the Others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+package org.codelibs.fess.rank.fusion;
+
+import org.codelibs.fess.entity.SearchRequestParams;
+import org.codelibs.fess.mylasta.action.FessUserBean;
+import org.dbflute.optional.OptionalThing;
+
+public abstract class RankFusionSearcher {
+
+    protected abstract SearchResult search(String query, SearchRequestParams params, OptionalThing<FessUserBean> userBean);
+
+}

src/main/java/org/codelibs/fess/rank/fusion/SearchResult.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2012-2023 CodeLibs Project and the Others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+package org.codelibs.fess.rank.fusion;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.lucene.search.TotalHits.Relation;
+import org.codelibs.fess.util.FacetResponse;
+
+public class SearchResult {
+
+    protected final List<Map<String, Object>> documentList;
+    protected final long allRecordCount;
+    protected final String allRecordCountRelation;
+    protected final long queryTime;
+    protected final boolean partialResults;
+    protected final FacetResponse facetResponse;
+
+    SearchResult(final List<Map<String, Object>> documentList, final long allRecordCount, final String allRecordCountRelation,
+            final long queryTime, final boolean partialResults, final FacetResponse facetResponse) {
+        this.documentList = documentList;
+        this.allRecordCount = allRecordCount;
+        this.allRecordCountRelation = allRecordCountRelation;
+        this.queryTime = queryTime;
+        this.partialResults = partialResults;
+        this.facetResponse = facetResponse;
+    }
+
+    public List<Map<String, Object>> getDocumentList() {
+        return documentList;
+    }
+
+    public long getAllRecordCount() {
+        return allRecordCount;
+    }
+
+    public String getAllRecordCountRelation() {
+        return allRecordCountRelation;
+    }
+
+    public long getQueryTime() {
+        return queryTime;
+    }
+
+    public boolean isPartialResults() {
+        return partialResults;
+    }
+
+    public FacetResponse getFacetResponse() {
+        return facetResponse;
+    }
+
+    public static SearchResultBuilder create() {
+        return new SearchResultBuilder();
+    }
+
+    static class SearchResultBuilder {
+
+        private long allRecordCount;
+        private String allRecordCountRelation = Relation.GREATER_THAN_OR_EQUAL_TO.toString();
+        private long queryTime;
+        private boolean partialResults;
+        private FacetResponse facetResponse;
+        private final List<Map<String, Object>> documentList = new ArrayList<>();
+
+        public SearchResultBuilder allRecordCount(final long allRecordCount) {
+            this.allRecordCount = allRecordCount;
+            return this;
+        }
+
+        public SearchResultBuilder allRecordCountRelation(final String allRecordCountRelation) {
+            this.allRecordCountRelation = allRecordCountRelation;
+            return this;
+        }
+
+        public SearchResultBuilder queryTime(final long queryTime) {
+            this.queryTime = queryTime;
+            return this;
+        }
+
+        public SearchResultBuilder partialResults(final boolean partialResults) {
+            this.partialResults = partialResults;
+            return this;
+        }
+
+        public SearchResultBuilder addDocument(final Map<String, Object> doc) {
+            documentList.add(doc);
+            return this;
+        }
+
+        public SearchResultBuilder facetResponse(final FacetResponse facetResponse) {
+            this.facetResponse = facetResponse;
+            return this;
+        }
+
+        public SearchResult build() {
+            return new SearchResult(documentList, //
+                    allRecordCount, //
+                    allRecordCountRelation, //
+                    queryTime, //
+                    partialResults, //
+                    facetResponse);
+        }
+    }
+}

src/main/java/org/codelibs/fess/util/ComponentUtil.java

@@ -81,6 +81,7 @@ import org.codelibs.fess.mylasta.direction.FessProp;
 import org.codelibs.fess.query.QueryFieldConfig;
 import org.codelibs.fess.query.QueryProcessor;
 import org.codelibs.fess.query.parser.QueryParser;
+import org.codelibs.fess.rank.fusion.RankFusionProcessor;
 import org.codelibs.fess.script.ScriptEngineFactory;
 import org.codelibs.fess.sso.SsoManager;
 import org.codelibs.fess.thumbnail.ThumbnailManager;
@@ -196,8 +197,6 @@ public final class ComponentUtil {
 
     private static final String CRAWLER_PROPERTIES = "systemProperties";
 
-    private static final String QUERY_RESPONSE_LIST = "queryResponseList";
-
     private static final String JOB_EXECUTOR_SUFFIX = "JobExecutor";
 
     private static final String KEY_MATCH_HELPER = "keyMatchHelper";
@@ -214,6 +213,8 @@ public final class ComponentUtil {
 
     private static final String CORS_HANDLER_FACTORY = "corsHandlerFactory";
 
+    private static final String RANK_FUSION_PROCESSOR = "rankFusionProcessor";
+
     private static IndexingHelper indexingHelper;
 
     private static CrawlingConfigHelper crawlingConfigHelper;
@@ -247,10 +248,6 @@ public final class ComponentUtil {
         return getComponent(cipherName);
     }
 
-    public static QueryResponseList getQueryResponseList() {
-        return getComponent(QUERY_RESPONSE_LIST);
-    }
-
     public static DynamicProperties getSystemProperties() {
         return getComponent(CRAWLER_PROPERTIES);
     }
@@ -519,6 +516,10 @@ public final class ComponentUtil {
         return getComponent(CORS_HANDLER_FACTORY);
     }
 
+    public static RankFusionProcessor getRankFusionProcessor() {
+        return getComponent(RANK_FUSION_PROCESSOR);
+    }
+
     public static <T> T getComponent(final Class<T> clazz) {
         try {
             return SingletonLaContainer.getComponent(clazz);

src/main/java/org/codelibs/fess/util/FacetResponse.java

@@ -94,4 +94,9 @@ public class FacetResponse {
         return fieldList;
     }
 
+    @Override
+    public String toString() {
+        return "FacetResponse [queryCountMap=" + queryCountMap + ", fieldList=" + fieldList + "]";
+    }
+
 }

src/main/java/org/codelibs/fess/util/QueryResponseList.java

@@ -17,35 +17,21 @@ package org.codelibs.fess.util;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Map;
 
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
-import org.codelibs.core.stream.StreamUtil;
-import org.codelibs.fess.Constants;
-import org.codelibs.fess.helper.QueryHelper;
-import org.codelibs.fess.helper.ViewHelper;
-import org.codelibs.fess.mylasta.direction.FessConfig;
-import org.dbflute.optional.OptionalEntity;
-import org.opensearch.action.search.SearchResponse;
-import org.opensearch.common.document.DocumentField;
-import org.opensearch.search.SearchHit;
-import org.opensearch.search.SearchHits;
-import org.opensearch.search.aggregations.Aggregations;
-import org.opensearch.search.fetch.subphase.highlight.HighlightField;
-
 public class QueryResponseList implements List<Map<String, Object>> {
 
-    private static final Logger logger = LogManager.getLogger(QueryResponseList.class);
-
     protected final List<Map<String, Object>> parent;
 
+    protected final int start;
+
+    protected final int offset;
+
     /** The value of current page number. */
-    protected int pageSize;
+    protected final int pageSize;
 
     /** The value of current page number. */
     protected int currentPageNumber;
@@ -76,127 +62,36 @@ public class QueryResponseList implements List<Map<String, Object>> {
 
     protected long queryTime;
 
-    public QueryResponseList() {
-        parent = new ArrayList<>();
-    }
-
     // for testing
-    protected QueryResponseList(final List<Map<String, Object>> parent) {
-        this.parent = parent;
-    }
-
-    public void init(final OptionalEntity<SearchResponse> searchResponseOpt, final int start, final int pageSize) {
-        searchResponseOpt.ifPresent(searchResponse -> {
-            final FessConfig fessConfig = ComponentUtil.getFessConfig();
-            final SearchHits searchHits = searchResponse.getHits();
-            allRecordCount = searchHits.getTotalHits().value;
-            allRecordCountRelation = searchHits.getTotalHits().relation.toString();
-            queryTime = searchResponse.getTook().millis();
-
-            if (searchResponse.getTotalShards() != searchResponse.getSuccessfulShards()) {
-                partialResults = true;
-            }
-
-            // build highlighting fields
-            final QueryHelper queryHelper = ComponentUtil.getQueryHelper();
-            final String hlPrefix = queryHelper.getHighlightPrefix();
-            for (final SearchHit searchHit : searchHits.getHits()) {
-                final Map<String, Object> docMap = parseSearchHit(fessConfig, hlPrefix, searchHit);
-
-                if (fessConfig.isResultCollapsed()) {
-                    final Map<String, SearchHits> innerHits = searchHit.getInnerHits();
-                    if (innerHits != null) {
-                        final SearchHits innerSearchHits = innerHits.get(fessConfig.getQueryCollapseInnerHitsName());
-                        if (innerSearchHits != null) {
-                            final long totalHits = innerSearchHits.getTotalHits().value;
-                            if (totalHits > 1) {
-                                docMap.put(fessConfig.getQueryCollapseInnerHitsName() + "_count", totalHits);
-                                final DocumentField bitsField = searchHit.getFields().get(fessConfig.getIndexFieldContentMinhashBits());
-                                if (bitsField != null && !bitsField.getValues().isEmpty()) {
-                                    docMap.put(fessConfig.getQueryCollapseInnerHitsName() + "_hash", bitsField.getValues().get(0));
-                                }
-                                docMap.put(fessConfig.getQueryCollapseInnerHitsName(), StreamUtil.stream(innerSearchHits.getHits())
-                                        .get(stream -> stream.map(v -> parseSearchHit(fessConfig, hlPrefix, v)).toArray(n -> new Map[n])));
-                            }
-                        }
-                    }
-                }
-
-                parent.add(docMap);
-            }
-
-            // facet
-            final Aggregations aggregations = searchResponse.getAggregations();
-            if (aggregations != null) {
-                facetResponse = new FacetResponse(aggregations);
-            }
-
-        });
-
+    protected QueryResponseList(final List<Map<String, Object>> documentList, final int start, final int pageSize, final int offset) {
+        this.parent = documentList;
+        this.offset = offset;
+        this.start = start;
+        this.pageSize = pageSize;
+    }
+
+    public QueryResponseList(final List<Map<String, Object>> documentList, final long allRecordCount, final String allRecordCountRelation,
+            final long queryTime, final boolean partialResults, final FacetResponse facetResponse, final int start, final int pageSize,
+            final int offset) {
+        this(documentList, start, pageSize, offset);
+        this.allRecordCount = allRecordCount;
+        this.allRecordCountRelation = allRecordCountRelation;
+        this.queryTime = queryTime;
+        this.partialResults = partialResults;
+        this.facetResponse = facetResponse;
         if (pageSize > 0) {
-            calculatePageInfo(start, pageSize);
+            calculatePageInfo();
         }
     }
 
-    protected Map<String, Object> parseSearchHit(final FessConfig fessConfig, final String hlPrefix, final SearchHit searchHit) {
-        final Map<String, Object> docMap = new HashMap<>(32);
-        if (searchHit.getSourceAsMap() == null) {
-            searchHit.getFields().forEach((key, value) -> {
-                docMap.put(key, value.getValue());
-            });
-        } else {
-            docMap.putAll(searchHit.getSourceAsMap());
-        }
-
-        final ViewHelper viewHelper = ComponentUtil.getViewHelper();
-
-        final Map<String, HighlightField> highlightFields = searchHit.getHighlightFields();
-        try {
-            if (highlightFields != null) {
-                highlightFields.values().stream().forEach(highlightField -> {
-                    final String text = viewHelper.createHighlightText(highlightField);
-                    if (text != null) {
-                        docMap.put(hlPrefix + highlightField.getName(), text);
-                    }
-                });
-                if (Constants.TEXT_FRAGMENT_TYPE_HIGHLIGHT.equals(fessConfig.getQueryHighlightTextFragmentType())) {
-                    docMap.put(Constants.TEXT_FRAGMENTS,
-                            viewHelper.createTextFragmentsByHighlight(highlightFields.values().toArray(n -> new HighlightField[n])));
-                }
-            }
-        } catch (final Exception e) {
-            if (logger.isDebugEnabled()) {
-                logger.debug("Could not create a highlighting value: {}", docMap, e);
-            }
-        }
-
-        if (Constants.TEXT_FRAGMENT_TYPE_QUERY.equals(fessConfig.getQueryHighlightTextFragmentType())) {
-            docMap.put(Constants.TEXT_FRAGMENTS, viewHelper.createTextFragmentsByQuery());
-        }
-
-        // ContentTitle
-        if (viewHelper != null) {
-            docMap.put(fessConfig.getResponseFieldContentTitle(), viewHelper.getContentTitle(docMap));
-            docMap.put(fessConfig.getResponseFieldContentDescription(), viewHelper.getContentDescription(docMap));
-            docMap.put(fessConfig.getResponseFieldUrlLink(), viewHelper.getUrlLink(docMap));
-            docMap.put(fessConfig.getResponseFieldSitePath(), viewHelper.getSitePath(docMap));
+    protected void calculatePageInfo() {
+        int startWithOffset = start - offset;
+        if (startWithOffset < 0) {
+            startWithOffset = 0;
         }
-
-        if (!docMap.containsKey(Constants.SCORE)) {
-            docMap.put(Constants.SCORE, searchHit.getScore());
-        }
-
-        if (!docMap.containsKey(fessConfig.getIndexFieldId())) {
-            docMap.put(fessConfig.getIndexFieldId(), searchHit.getId());
-        }
-        return docMap;
-    }
-
-    protected void calculatePageInfo(final int start, final int size) {
-        pageSize = size;
         allPageCount = (int) ((allRecordCount - 1) / pageSize) + 1;
-        existPrevPage = start > 0;
-        existNextPage = start < (long) (allPageCount - 1) * (long) pageSize;
+        existPrevPage = startWithOffset > 0;
+        existNextPage = startWithOffset < (long) (allPageCount - 1) * (long) pageSize;
         currentPageNumber = start / pageSize + 1;
         if (existNextPage && size() < pageSize) {
             // collapsing
@@ -347,6 +242,14 @@ public class QueryResponseList implements List<Map<String, Object>> {
         return parent.toArray(a);
     }
 
+    public int getStart() {
+        return start;
+    }
+
+    public int getOffset() {
+        return offset;
+    }
+
     public int getPageSize() {
         return pageSize;
     }
@@ -415,4 +318,14 @@ public class QueryResponseList implements List<Map<String, Object>> {
         return queryTime;
     }
 
+    @Override
+    public String toString() {
+        return "QueryResponseList [parent=" + parent + ", start=" + start + ", offset=" + offset + ", pageSize=" + pageSize
+                + ", currentPageNumber=" + currentPageNumber + ", allRecordCount=" + allRecordCount + ", allRecordCountRelation="
+                + allRecordCountRelation + ", allPageCount=" + allPageCount + ", existNextPage=" + existNextPage + ", existPrevPage="
+                + existPrevPage + ", currentStartRecordNumber=" + currentStartRecordNumber + ", currentEndRecordNumber="
+                + currentEndRecordNumber + ", pageNumberList=" + pageNumberList + ", searchQuery=" + searchQuery + ", execTime=" + execTime
+                + ", facetResponse=" + facetResponse + ", partialResults=" + partialResults + ", queryTime=" + queryTime + "]";
+    }
+
 }

src/main/resources/app.xml

@@ -7,15 +7,16 @@
 	<include path="lasta_job.xml"/>
 
 	<include path="fess.xml"/>
-	<include path="fess_ldap.xml"/>
 	<include path="fess_api.xml"/>
 	<include path="fess_cors.xml"/>
 	<include path="fess_dict.xml"/>
 	<include path="fess_job.xml"/>
-	<include path="fess_thumbnail.xml"/>
-	<include path="fess_sso.xml"/>
-	<include path="fess_score.xml"/>
+	<include path="fess_ldap.xml"/>
 	<include path="fess_query.xml"/>
+	<include path="fess_rankfusion.xml"/>
+	<include path="fess_score.xml"/>
+	<include path="fess_sso.xml"/>
+	<include path="fess_thumbnail.xml"/>
 
 	<include path="crawler/client.xml" />
 	<include path="crawler/mimetype.xml" />
@@ -103,8 +104,6 @@
 	</component>
 	<component name="suggestHelper" class="org.codelibs.fess.helper.SuggestHelper">
 	</component>
-	<component name="queryResponseList" class="org.codelibs.fess.util.QueryResponseList" instance="prototype">
-	</component>
 	<component name="gsaConfigParser" class="org.codelibs.fess.util.GsaConfigParser" instance="prototype">
 	</component>
 

src/main/resources/fess_config.properties

@@ -604,6 +604,12 @@ labels.facet_filetype_pdf=filetype:pdf\t\
 labels.facet_filetype_txt=filetype:txt\t\
 labels.facet_filetype_others=filetype:others\n\
 
+# ranking
+rank.fusion.window_size=200
+rank.fusion.rank_constant=20
+rank.fusion.threads=-1
+rank.fusion.score_field=rf_score
+
 # acl
 smb.role.from.file=true
 smb.available.sid.types=1,2,4:2,5:1

src/main/resources/fess_rankfusion.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE components PUBLIC "-//DBFLUTE//DTD LastaDi 1.0//EN"
+	"http://dbflute.org/meta/lastadi10.dtd">
+<components>
+	<component name="rankFusionProcessor"
+		class="org.codelibs.fess.rank.fusion.RankFusionProcessor">
+		<postConstruct name="setSeacher">
+			<arg>
+				<component
+					class="org.codelibs.fess.rank.fusion.DefaultSearcher">
+				</component>
+			</arg>
+		</postConstruct>
+	</component>
+</components>

src/test/java/org/codelibs/fess/rank/fusion/RankFusionProcessorTest.java

@@ -0,0 +1,371 @@
+/*
+ * Copyright 2012-2023 CodeLibs Project and the Others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+ * either express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+package org.codelibs.fess.rank.fusion;
+
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+
+import org.apache.lucene.search.TotalHits.Relation;
+import org.codelibs.fess.entity.FacetInfo;
+import org.codelibs.fess.entity.GeoInfo;
+import org.codelibs.fess.entity.HighlightInfo;
+import org.codelibs.fess.entity.SearchRequestParams;
+import org.codelibs.fess.mylasta.action.FessUserBean;
+import org.codelibs.fess.rank.fusion.SearchResult.SearchResultBuilder;
+import org.codelibs.fess.unit.UnitFessTestCase;
+import org.codelibs.fess.util.QueryResponseList;
+import org.dbflute.optional.OptionalThing;
+
+public class RankFusionProcessorTest extends UnitFessTestCase {
+
+    private static final String ID_FIELD = "_id";
+
+    public void test_default_1000docs_10size() throws Exception {
+        String query = "*";
+        int allRecordCount = 1000;
+        int pageSize = 10;
+        try (RankFusionProcessor rankFusionProcessor = new RankFusionProcessor()) {
+            rankFusionProcessor.setSeacher(new TestMainSearcher(allRecordCount));
+            rankFusionProcessor.init();
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(0, pageSize, 0),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount, list.getAllRecordCount());
+                assertEquals(100, list.getAllPageCount());
+                assertEquals(10, list.getCurrentEndRecordNumber());
+                assertEquals(1, list.getCurrentPageNumber());
+                assertEquals(1, list.getCurrentStartRecordNumber());
+                assertEquals(0, list.getOffset());
+                assertEquals(10, list.getPageSize());
+                assertEquals(0, list.getStart());
+                assertEquals("0", list.get(0).get(ID_FIELD));
+                assertEquals("9", list.get(9).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(10, pageSize, 0),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount, list.getAllRecordCount());
+                assertEquals(100, list.getAllPageCount());
+                assertEquals(20, list.getCurrentEndRecordNumber());
+                assertEquals(2, list.getCurrentPageNumber());
+                assertEquals(11, list.getCurrentStartRecordNumber());
+                assertEquals(0, list.getOffset());
+                assertEquals(10, list.getPageSize());
+                assertEquals(10, list.getStart());
+                assertEquals("10", list.get(0).get(ID_FIELD));
+                assertEquals("19", list.get(9).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(990, pageSize, 0),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount, list.getAllRecordCount());
+                assertEquals(100, list.getAllPageCount());
+                assertEquals(1000, list.getCurrentEndRecordNumber());
+                assertEquals(100, list.getCurrentPageNumber());
+                assertEquals(991, list.getCurrentStartRecordNumber());
+                assertEquals(0, list.getOffset());
+                assertEquals(10, list.getPageSize());
+                assertEquals(990, list.getStart());
+                assertEquals("990", list.get(0).get(ID_FIELD));
+                assertEquals("999", list.get(9).get(ID_FIELD));
+            } else {
+                fail();
+            }
+        }
+    }
+
+    public void test_1searcher10_1000docs_100size() throws Exception {
+        String query = "*";
+        int allRecordCount = 1000;
+        int pageSize = 100;
+        int offset = 45;
+        try (RankFusionProcessor rankFusionProcessor = new RankFusionProcessor()) {
+            rankFusionProcessor.setSeacher(new TestMainSearcher(allRecordCount));
+            rankFusionProcessor.register(new TestSubSearcher(10, 45, 45));
+            rankFusionProcessor.init();
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(0, pageSize, 0),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount + offset, list.getAllRecordCount());
+                assertEquals(11, list.getAllPageCount());
+                assertEquals(100, list.getCurrentEndRecordNumber());
+                assertEquals(1, list.getCurrentPageNumber());
+                assertEquals(1, list.getCurrentStartRecordNumber());
+                assertEquals(offset, list.getOffset());
+                assertEquals(100, list.getPageSize());
+                assertEquals(0, list.getStart());
+                assertEquals("0", list.get(0).get(ID_FIELD));
+                assertEquals("9", list.get(1).get(ID_FIELD));
+                assertEquals("1", list.get(2).get(ID_FIELD));
+                assertEquals("8", list.get(3).get(ID_FIELD));
+                assertEquals("2", list.get(4).get(ID_FIELD));
+                assertEquals("7", list.get(5).get(ID_FIELD));
+                assertEquals("3", list.get(6).get(ID_FIELD));
+                assertEquals("6", list.get(7).get(ID_FIELD));
+                assertEquals("4", list.get(8).get(ID_FIELD));
+                assertEquals("5", list.get(9).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(0, pageSize, offset),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount + offset, list.getAllRecordCount());
+                assertEquals(11, list.getAllPageCount());
+                assertEquals(100, list.getCurrentEndRecordNumber());
+                assertEquals(1, list.getCurrentPageNumber());
+                assertEquals(1, list.getCurrentStartRecordNumber());
+                assertEquals(offset, list.getOffset());
+                assertEquals(100, list.getPageSize());
+                assertEquals(0, list.getStart());
+                assertEquals("0", list.get(0).get(ID_FIELD));
+                assertEquals("9", list.get(1).get(ID_FIELD));
+                assertEquals("1", list.get(2).get(ID_FIELD));
+                assertEquals("8", list.get(3).get(ID_FIELD));
+                assertEquals("2", list.get(4).get(ID_FIELD));
+                assertEquals("7", list.get(5).get(ID_FIELD));
+                assertEquals("3", list.get(6).get(ID_FIELD));
+                assertEquals("6", list.get(7).get(ID_FIELD));
+                assertEquals("4", list.get(8).get(ID_FIELD));
+                assertEquals("5", list.get(9).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(100, pageSize, offset),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount + offset, list.getAllRecordCount());
+                assertEquals(11, list.getAllPageCount());
+                assertEquals(200, list.getCurrentEndRecordNumber());
+                assertEquals(2, list.getCurrentPageNumber());
+                assertEquals(101, list.getCurrentStartRecordNumber());
+                assertEquals(offset, list.getOffset());
+                assertEquals(100, list.getPageSize());
+                assertEquals(100, list.getStart());
+                assertEquals("55", list.get(0).get(ID_FIELD));
+                assertEquals("154", list.get(99).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(900, pageSize, offset),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount + offset, list.getAllRecordCount());
+                assertEquals(11, list.getAllPageCount());
+                assertEquals(1000, list.getCurrentEndRecordNumber());
+                assertEquals(10, list.getCurrentPageNumber());
+                assertEquals(901, list.getCurrentStartRecordNumber());
+                assertEquals(offset, list.getOffset());
+                assertEquals(100, list.getPageSize());
+                assertEquals(900, list.getStart());
+                assertEquals("855", list.get(0).get(ID_FIELD));
+                assertEquals("954", list.get(99).get(ID_FIELD));
+            } else {
+                fail();
+            }
+
+            if (rankFusionProcessor.search(query, new TestSearchRequestParams(1000, pageSize, offset),
+                    OptionalThing.empty()) instanceof QueryResponseList list) {
+                assertEquals(pageSize, list.size());
+                assertEquals(allRecordCount + offset, list.getAllRecordCount());
+                assertEquals(11, list.getAllPageCount());
+                assertEquals(1045, list.getCurrentEndRecordNumber());
+                assertEquals(11, list.getCurrentPageNumber());
+                assertEquals(1001, list.getCurrentStartRecordNumber());
+                assertEquals(offset, list.getOffset());
+                assertEquals(100, list.getPageSize());
+                assertEquals(1000, list.getStart());
+                assertEquals("955", list.get(0).get(ID_FIELD));
+                assertEquals("999", list.get(44).get(ID_FIELD));
+            } else {
+                fail();
+            }
+        }
+    }
+
+    static class TestMainSearcher extends RankFusionSearcher {
+
+        private long allRecordCount;
+
+        TestMainSearcher(int allRecordCount) {
+            this.allRecordCount = allRecordCount;
+        }
+
+        @Override
+        protected SearchResult search(String query, SearchRequestParams params, OptionalThing<FessUserBean> userBean) {
+            int start = params.getStartPosition();
+            int size = params.getPageSize();
+            SearchResultBuilder builder = SearchResult.create();
+            for (int i = start; i < start + size; i++) {
+                Map<String, Object> doc = new HashMap<>();
+                doc.put(ID_FIELD, Integer.toString(i));
+                doc.put("score", 1.0f / (i + 1));
+                builder.addDocument(doc);
+            }
+            builder.allRecordCount(allRecordCount);
+            if (allRecordCount < 10000) {
+                builder.allRecordCountRelation(Relation.EQUAL_TO.toString());
+            }
+            return builder.build();
+        }
+    }
+
+    static class TestSubSearcher extends RankFusionSearcher {
+
+        private int mainSize;
+        private int inSize;
+        private int outSize;
+
+        TestSubSearcher(int mainSize, int inSize, int outSize) {
+            this.mainSize = mainSize;
+            this.inSize = inSize;
+            this.outSize = outSize;
+        }
+
+        @Override
+        protected SearchResult search(String query, SearchRequestParams params, OptionalThing<FessUserBean> userBean) {
+            SearchResultBuilder builder = SearchResult.create();
+            for (int i = 0; i < mainSize; i++) {
+                Map<String, Object> doc = new HashMap<>();
+                doc.put(ID_FIELD, Integer.toString(mainSize - i - 1));
+                doc.put("score", 1.0f / (i + 2));
+                builder.addDocument(doc);
+            }
+            for (int i = 100; i < inSize + 100; i++) {
+                Map<String, Object> doc = new HashMap<>();
+                doc.put(ID_FIELD, Integer.toString(i));
+                doc.put("score", 1.0f / (mainSize + i + 2));
+                builder.addDocument(doc);
+            }
+            for (int i = 200; i < outSize + 200; i++) {
+                Map<String, Object> doc = new HashMap<>();
+                doc.put(ID_FIELD, Integer.toString(i));
+                doc.put("score", 1.0f / (mainSize + i + 3));
+                builder.addDocument(doc);
+            }
+            builder.allRecordCount(mainSize + inSize + outSize);
+            return builder.build();
+        }
+    }
+
+    static class TestSearchRequestParams extends SearchRequestParams {
+
+        private int startPosition;
+
+        private int pageSize;
+
+        private int offset;
+
+        TestSearchRequestParams(int startPosition, int pageSize, int offset) {
+            this.startPosition = startPosition;
+            this.pageSize = pageSize;
+            this.offset = offset;
+        }
+
+        @Override
+        public String getQuery() {
+            return null;
+        }
+
+        @Override
+        public Map<String, String[]> getFields() {
+            return null;
+        }
+
+        @Override
+        public Map<String, String[]> getConditions() {
+            return null;
+        }
+
+        @Override
+        public String[] getLanguages() {
+            return null;
+        }
+
+        @Override
+        public GeoInfo getGeoInfo() {
+            return null;
+        }
+
+        @Override
+        public FacetInfo getFacetInfo() {
+            return null;
+        }
+
+        @Override
+        public HighlightInfo getHighlightInfo() {
+            return null;
+        }
+
+        @Override
+        public String getSort() {
+            return null;
+        }
+
+        @Override
+        public int getStartPosition() {
+            return startPosition;
+        }
+
+        @Override
+        public int getOffset() {
+            return offset;
+        }
+
+        @Override
+        public int getPageSize() {
+            return pageSize;
+        }
+
+        @Override
+        public String[] getExtraQueries() {
+            return null;
+        }
+
+        @Override
+        public Object getAttribute(String name) {
+            return null;
+        }
+
+        @Override
+        public Locale getLocale() {
+            return null;
+        }
+
+        @Override
+        public SearchRequestType getType() {
+            return null;
+        }
+
+        @Override
+        public String getSimilarDocHash() {
+            return null;
+        }
+
+    }
+}

src/test/java/org/codelibs/fess/util/QueryResponseListTest.java

@@ -15,9 +15,7 @@
  */
 package org.codelibs.fess.util;
 
-import java.util.ArrayList;
 import java.util.List;
-import java.util.Map;
 
 import org.codelibs.fess.unit.UnitFessTestCase;
 
@@ -25,13 +23,13 @@ public class QueryResponseListTest extends UnitFessTestCase {
     public void test_calculatePageInfo_page0() {
         QueryResponseList qrList;
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 0;
             }
         };
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(0, qrList.getAllRecordCount());
@@ -45,14 +43,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
     public void test_calculatePageInfo_page1() {
         QueryResponseList qrList;
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 10;
             }
         };
         qrList.allRecordCount = 10;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(10, qrList.getAllRecordCount());
@@ -62,14 +60,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(10, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 20;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(20, qrList.getAllRecordCount());
@@ -79,14 +77,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 21;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(21, qrList.getAllRecordCount());
@@ -96,14 +94,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 40;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(40, qrList.getAllRecordCount());
@@ -113,14 +111,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 41;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(41, qrList.getAllRecordCount());
@@ -134,14 +132,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
     public void test_calculatePageInfo_page2() {
         QueryResponseList qrList;
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 1;
             }
         };
         qrList.allRecordCount = 21;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(2, qrList.getCurrentPageNumber());
         assertEquals(21, qrList.getAllRecordCount());
@@ -151,14 +149,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(21, qrList.getCurrentStartRecordNumber());
         assertEquals(21, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 40;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(2, qrList.getCurrentPageNumber());
         assertEquals(40, qrList.getAllRecordCount());
@@ -168,14 +166,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(21, qrList.getCurrentStartRecordNumber());
         assertEquals(40, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 41;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(2, qrList.getCurrentPageNumber());
         assertEquals(41, qrList.getAllRecordCount());
@@ -185,14 +183,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(21, qrList.getCurrentStartRecordNumber());
         assertEquals(40, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 61;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(2, qrList.getCurrentPageNumber());
         assertEquals(61, qrList.getAllRecordCount());
@@ -207,26 +205,26 @@ public class QueryResponseListTest extends UnitFessTestCase {
         QueryResponseList qrList;
         List<String> pnList;
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 20;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(1, pnList.size());
         assertEquals("1", pnList.get(0));
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 61;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(4, pnList.size());
         assertEquals("1", pnList.get(0));
@@ -234,14 +232,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals("3", pnList.get(2));
         assertEquals("4", pnList.get(3));
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 200;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(6, pnList.size());
         assertEquals("1", pnList.get(0));
@@ -251,27 +249,27 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals("5", pnList.get(4));
         assertEquals("6", pnList.get(5));
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 1;
             }
         };
         qrList.allRecordCount = 21;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(2, pnList.size());
         assertEquals("1", pnList.get(0));
         assertEquals("2", pnList.get(1));
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 61;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(4, pnList.size());
         assertEquals("1", pnList.get(0));
@@ -279,14 +277,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals("3", pnList.get(2));
         assertEquals("4", pnList.get(3));
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 20;
             }
         };
         qrList.allRecordCount = 200;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         pnList = qrList.getPageNumberList();
         assertEquals(7, pnList.size());
         assertEquals("1", pnList.get(0));
@@ -302,13 +300,13 @@ public class QueryResponseListTest extends UnitFessTestCase {
     public void test_calculatePageInfo_collapse() {
         QueryResponseList qrList;
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 0;
             }
         };
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(0, qrList.getAllRecordCount());
@@ -318,14 +316,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(0, qrList.getCurrentStartRecordNumber());
         assertEquals(0, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 10;
             }
         };
         qrList.allRecordCount = 20;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(20, qrList.getAllRecordCount());
@@ -335,14 +333,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 10;
             }
         };
         qrList.allRecordCount = 21;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(21, qrList.getAllRecordCount());
@@ -352,14 +350,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 0, 20, 0) {
             @Override
             public int size() {
                 return 21;
             }
         };
         qrList.allRecordCount = 41;
-        qrList.calculatePageInfo(0, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(1, qrList.getCurrentPageNumber());
         assertEquals(41, qrList.getAllRecordCount());
@@ -369,14 +367,14 @@ public class QueryResponseListTest extends UnitFessTestCase {
         assertEquals(1, qrList.getCurrentStartRecordNumber());
         assertEquals(20, qrList.getCurrentEndRecordNumber());
 
-        qrList = new QueryResponseList(new ArrayList<Map<String, Object>>()) {
+        qrList = new QueryResponseList(null, 20, 20, 0) {
             @Override
             public int size() {
                 return 1;
             }
         };
         qrList.allRecordCount = 41;
-        qrList.calculatePageInfo(20, 20);
+        qrList.calculatePageInfo();
         assertEquals(20, qrList.getPageSize());
         assertEquals(2, qrList.getCurrentPageNumber());
         assertEquals(41, qrList.getAllRecordCount());

src/test/java/org/codelibs/fess/util/QueryStringBuilderTest.java

@@ -131,6 +131,11 @@ public class QueryStringBuilderTest extends UnitFessTestCase {
                 return 0;
             }
 
+            @Override
+            public int getOffset() {
+                return 0;
+            }
+
             @Override
             public int getPageSize() {
                 return 0;