Change `has_child`, `has_parent` queries and `childen` aggregation to work with the new join field type and

at the same time maintaining support for the `_parent` meta field type.

Relates to #20257

6 files changed, 133 insertions, 23 deletions

diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/aggregations/ChildrenAggregationBuilder.java b/modules/parent-join/src/main/java/org/elasticsearch/join/aggregations/ChildrenAggregationBuilder.java
index 35dc4eacbf..3560736e44 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/aggregations/ChildrenAggregationBuilder.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/aggregations/ChildrenAggregationBuilder.java
@@ -30,6 +30,8 @@ import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.ParentFieldMapper;
 import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.join.mapper.ParentIdFieldMapper;
+import org.elasticsearch.join.mapper.ParentJoinFieldMapper;
 import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.support.FieldContext;
@@ -92,8 +94,30 @@ public class ChildrenAggregationBuilder
     @Override
     protected ValuesSourceConfig<WithOrdinals> resolveConfig(SearchContext context) {
         ValuesSourceConfig<WithOrdinals> config = new ValuesSourceConfig<>(ValuesSourceType.BYTES);
-        DocumentMapper childDocMapper = context.mapperService().documentMapper(childType);
+        if (context.mapperService().getIndexSettings().isSingleType()) {
+            joinFieldResolveConfig(context, config);
+        } else {
+            parentFieldResolveConfig(context, config);
+        }
+        return config;
+    }
+
+    private void joinFieldResolveConfig(SearchContext context, ValuesSourceConfig<WithOrdinals> config) {
+        ParentJoinFieldMapper parentJoinFieldMapper = ParentJoinFieldMapper.getMapper(context.mapperService());
+        ParentIdFieldMapper parentIdFieldMapper = parentJoinFieldMapper.getParentIdFieldMapper(childType, false);
+        if (parentIdFieldMapper != null) {
+            parentFilter = parentIdFieldMapper.getParentFilter();
+            childFilter = parentIdFieldMapper.getChildFilter(childType);
+            MappedFieldType fieldType = parentIdFieldMapper.fieldType();
+            final SortedSetDVOrdinalsIndexFieldData fieldData = context.fieldData().getForField(fieldType);
+            config.fieldContext(new FieldContext(fieldType.name(), fieldData, fieldType));
+        } else {
+            config.unmapped(true);
+        }
+    }
 
+    private void parentFieldResolveConfig(SearchContext context, ValuesSourceConfig<WithOrdinals> config) {
+        DocumentMapper childDocMapper = context.mapperService().documentMapper(childType);
         if (childDocMapper != null) {
             ParentFieldMapper parentFieldMapper = childDocMapper.parentFieldMapper();
             if (!parentFieldMapper.active()) {
@@ -107,14 +131,13 @@ public class ChildrenAggregationBuilder
                 MappedFieldType parentFieldType = parentDocMapper.parentFieldMapper().getParentJoinFieldType();
                 final SortedSetDVOrdinalsIndexFieldData fieldData = context.fieldData().getForField(parentFieldType);
                 config.fieldContext(new FieldContext(parentFieldType.name(), fieldData,
-                        parentFieldType));
+                    parentFieldType));
             } else {
                 config.unmapped(true);
             }
         } else {
             config.unmapped(true);
         }
-        return config;
     }
 
     @Override
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/MetaJoinFieldMapper.java b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/MetaJoinFieldMapper.java
index 43608e9b54..db9fae9b47 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/MetaJoinFieldMapper.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/MetaJoinFieldMapper.java
@@ -40,7 +40,7 @@ import java.util.List;
  * This class is also used to quickly retrieve the parent-join field defined in a mapping without
  * specifying the name of the field.
  */
-class MetaJoinFieldMapper extends FieldMapper {
+public class MetaJoinFieldMapper extends FieldMapper {
     static final String NAME = "_parent_join";
     static final String CONTENT_TYPE = "parent_join";
 
@@ -68,8 +68,9 @@ class MetaJoinFieldMapper extends FieldMapper {
         }
     }
 
-    static final class MetaJoinFieldType extends StringFieldType {
-        ParentJoinFieldMapper mapper;
+    public static class MetaJoinFieldType extends StringFieldType {
+
+        private ParentJoinFieldMapper mapper;
 
         MetaJoinFieldType() {}
 
@@ -100,6 +101,10 @@ class MetaJoinFieldMapper extends FieldMapper {
             BytesRef binaryValue = (BytesRef) value;
             return binaryValue.utf8ToString();
         }
+
+        public ParentJoinFieldMapper getMapper() {
+            return mapper;
+        }
     }
 
     MetaJoinFieldMapper(String name, MappedFieldType fieldType, Settings indexSettings) {
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentIdFieldMapper.java b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentIdFieldMapper.java
index 7a042eae84..cc2815c373 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentIdFieldMapper.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentIdFieldMapper.java
@@ -23,6 +23,12 @@ import org.apache.lucene.document.Field;
 import org.apache.lucene.document.SortedDocValuesField;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.ConstantScoreQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.settings.Settings;
@@ -47,7 +53,7 @@ public final class ParentIdFieldMapper extends FieldMapper {
     static final String CONTENT_TYPE = "parent";
 
     static class Defaults {
-        public static final MappedFieldType FIELD_TYPE = new ParentIdFieldType();
+        static final MappedFieldType FIELD_TYPE = new ParentIdFieldType();
 
         static {
             FIELD_TYPE.setTokenized(false);
@@ -86,7 +92,7 @@ public final class ParentIdFieldMapper extends FieldMapper {
     }
 
     public static final class ParentIdFieldType extends StringFieldType {
-        public ParentIdFieldType() {
+        ParentIdFieldType() {
             setIndexAnalyzer(Lucene.KEYWORD_ANALYZER);
             setSearchAnalyzer(Lucene.KEYWORD_ANALYZER);
         }
@@ -145,6 +151,9 @@ public final class ParentIdFieldMapper extends FieldMapper {
         return parentName;
     }
 
+    public Query getParentFilter() {
+        return new TermQuery(new Term(name().substring(0, name().indexOf('#')), parentName));
+    }
     /**
      * Returns the children names associated with this mapper.
      */
@@ -152,6 +161,18 @@ public final class ParentIdFieldMapper extends FieldMapper {
         return children;
     }
 
+    public Query getChildFilter(String type) {
+        return new TermQuery(new Term(name().substring(0, name().indexOf('#')), type));
+    }
+
+    public Query getChildrenFilter() {
+        BooleanQuery.Builder builder = new BooleanQuery.Builder();
+        for (String child : children) {
+            builder.add(getChildFilter(child), BooleanClause.Occur.SHOULD);
+        }
+        return new ConstantScoreQuery(builder.build());
+    }
+
     @Override
     protected void parseCreateField(ParseContext context, List<IndexableField> fields) throws IOException {
         if (context.externalValueSet() == false) {
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentJoinFieldMapper.java b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentJoinFieldMapper.java
index d9c12d85c1..ecabbb096e 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentJoinFieldMapper.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/mapper/ParentJoinFieldMapper.java
@@ -81,7 +81,7 @@ public final class ParentJoinFieldMapper extends FieldMapper {
     public static ParentJoinFieldMapper getMapper(MapperService service) {
         MetaJoinFieldMapper.MetaJoinFieldType fieldType =
             (MetaJoinFieldMapper.MetaJoinFieldType) service.fullName(MetaJoinFieldMapper.NAME);
-        return fieldType == null ? null : fieldType.mapper;
+        return fieldType == null ? null : fieldType.getMapper();
     }
 
     private static String getParentIdFieldName(String joinFieldName, String parentName) {
@@ -121,11 +121,11 @@ public final class ParentJoinFieldMapper extends FieldMapper {
         }
     }
 
-    static class Builder extends FieldMapper.Builder<Builder, ParentJoinFieldMapper> {
+    public static class Builder extends FieldMapper.Builder<Builder, ParentJoinFieldMapper> {
         final List<ParentIdFieldMapper.Builder> parentIdFieldBuilders = new ArrayList<>();
         boolean eagerGlobalOrdinals = true;
 
-        Builder(String name) {
+        public Builder(String name) {
             super(name, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE);
             builder = this;
         }
@@ -431,4 +431,5 @@ public final class ParentJoinFieldMapper extends FieldMapper {
             }
         }
     }
+
 }
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
index f574236b35..6485b8f649 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasChildQueryBuilder.java
@@ -49,6 +49,8 @@ import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.query.QueryRewriteContext;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.join.mapper.ParentIdFieldMapper;
+import org.elasticsearch.join.mapper.ParentJoinFieldMapper;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -305,6 +307,34 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
 
     @Override
     protected Query doToQuery(QueryShardContext context) throws IOException {
+        if (context.getIndexSettings().isSingleType()) {
+            return joinFieldDoToQuery(context);
+        } else {
+            return parentFieldDoToQuery(context);
+        }
+    }
+
+    private Query joinFieldDoToQuery(QueryShardContext context) throws IOException {
+        ParentJoinFieldMapper joinFieldMapper = ParentJoinFieldMapper.getMapper(context.getMapperService());
+        ParentIdFieldMapper parentIdFieldMapper = joinFieldMapper.getParentIdFieldMapper(type, false);
+        if (parentIdFieldMapper != null) {
+            Query parentFilter = parentIdFieldMapper.getParentFilter();
+            Query childFilter = parentIdFieldMapper.getChildFilter(type);
+            Query innerQuery = Queries.filtered(query.toQuery(context), childFilter);
+            MappedFieldType fieldType = parentIdFieldMapper.fieldType();
+            final SortedSetDVOrdinalsIndexFieldData fieldData = context.getForField(fieldType);
+            return new LateParsingQuery(parentFilter, innerQuery, minChildren(), maxChildren(),
+                fieldType.name(), scoreMode, fieldData, context.getSearchSimilarity());
+        } else {
+            if (ignoreUnmapped) {
+                return new MatchNoDocsQuery();
+            } else {
+                throw new QueryShardException(context, "[" + NAME + "] join field has no parent type configured");
+            }
+        }
+    }
+
+    private Query parentFieldDoToQuery(QueryShardContext context) throws IOException {
         Query innerQuery;
         final String[] previousTypes = context.getTypes();
         context.setTypes(type);
@@ -313,8 +343,7 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
         } finally {
             context.setTypes(previousTypes);
         }
-
-        DocumentMapper childDocMapper = context.documentMapper(type);
+        DocumentMapper childDocMapper = context.getMapperService().documentMapper(type);
         if (childDocMapper == null) {
             if (ignoreUnmapped) {
                 return new MatchNoDocsQuery();
@@ -330,16 +359,17 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
         DocumentMapper parentDocMapper = context.getMapperService().documentMapper(parentType);
         if (parentDocMapper == null) {
             throw new QueryShardException(context,
-                    "[" + NAME + "] Type [" + type + "] points to a non existent parent type [" + parentType + "]");
+                "[" + NAME + "] Type [" + type + "] points to a non existent parent type [" + parentType + "]");
         }
 
         // wrap the query with type query
         innerQuery = Queries.filtered(innerQuery, childDocMapper.typeFilter(context));
 
+        String joinField = ParentFieldMapper.joinField(parentType);
         final MappedFieldType parentFieldType = parentDocMapper.parentFieldMapper().getParentJoinFieldType();
         final SortedSetDVOrdinalsIndexFieldData fieldData = context.getForField(parentFieldType);
         return new LateParsingQuery(parentDocMapper.typeFilter(context), innerQuery, minChildren(), maxChildren(),
-            parentType, scoreMode, fieldData, context.getSearchSimilarity());
+            joinField, scoreMode, fieldData, context.getSearchSimilarity());
     }
 
     /**
@@ -358,19 +388,19 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
         private final Query innerQuery;
         private final int minChildren;
         private final int maxChildren;
-        private final String parentType;
+        private final String joinField;
         private final ScoreMode scoreMode;
         private final SortedSetDVOrdinalsIndexFieldData fieldDataJoin;
         private final Similarity similarity;
 
         LateParsingQuery(Query toQuery, Query innerQuery, int minChildren, int maxChildren,
-                         String parentType, ScoreMode scoreMode,
+                         String joinField, ScoreMode scoreMode,
                          SortedSetDVOrdinalsIndexFieldData fieldData, Similarity similarity) {
             this.toQuery = toQuery;
             this.innerQuery = innerQuery;
             this.minChildren = minChildren;
             this.maxChildren = maxChildren;
-            this.parentType = parentType;
+            this.joinField = joinField;
             this.scoreMode = scoreMode;
             this.fieldDataJoin = fieldData;
             this.similarity = similarity;
@@ -383,7 +413,6 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
                 return rewritten;
             }
             if (reader instanceof DirectoryReader) {
-                String joinField = ParentFieldMapper.joinField(parentType);
                 IndexSearcher indexSearcher = new IndexSearcher(reader);
                 indexSearcher.setQueryCache(null);
                 indexSearcher.setSimilarity(similarity);
@@ -414,18 +443,18 @@ public class HasChildQueryBuilder extends AbstractQueryBuilder<HasChildQueryBuil
             if (maxChildren != that.maxChildren) return false;
             if (!toQuery.equals(that.toQuery)) return false;
             if (!innerQuery.equals(that.innerQuery)) return false;
-            if (!parentType.equals(that.parentType)) return false;
+            if (!joinField.equals(that.joinField)) return false;
             return scoreMode == that.scoreMode;
         }
 
         @Override
         public int hashCode() {
-            return Objects.hash(classHash(), toQuery, innerQuery, minChildren, maxChildren, parentType, scoreMode);
+            return Objects.hash(getClass(), toQuery, innerQuery, minChildren, maxChildren, joinField, scoreMode);
         }
 
         @Override
         public String toString(String s) {
-            return "LateParsingQuery {parentType=" + parentType + "}";
+            return "LateParsingQuery {joinField=" + joinField + "}";
         }
 
         public int getMinChildren() {
diff --git a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
index 7bcbf7c611..3d23fac01b 100644
--- a/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
+++ b/modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java
@@ -55,6 +55,8 @@ import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.query.QueryRewriteContext;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.join.mapper.ParentIdFieldMapper;
+import org.elasticsearch.join.mapper.ParentJoinFieldMapper;
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.search.SearchHitField;
 import org.elasticsearch.search.fetch.subphase.InnerHitsContext;
@@ -187,6 +189,35 @@ public class HasParentQueryBuilder extends AbstractQueryBuilder<HasParentQueryBu
 
     @Override
     protected Query doToQuery(QueryShardContext context) throws IOException {
+        if (context.getIndexSettings().isSingleType()) {
+            return joinFieldDoToQuery(context);
+        } else  {
+            return parentFieldDoToQuery(context);
+        }
+    }
+
+    private Query joinFieldDoToQuery(QueryShardContext context) throws IOException {
+        ParentJoinFieldMapper joinFieldMapper = ParentJoinFieldMapper.getMapper(context.getMapperService());
+        ParentIdFieldMapper parentIdFieldMapper = joinFieldMapper.getParentIdFieldMapper(type, true);
+        if (parentIdFieldMapper != null) {
+            Query parentFilter = parentIdFieldMapper.getParentFilter();
+            Query innerQuery = Queries.filtered(query.toQuery(context), parentFilter);
+            Query childFilter = parentIdFieldMapper.getChildrenFilter();
+            MappedFieldType fieldType = parentIdFieldMapper.fieldType();
+            final SortedSetDVOrdinalsIndexFieldData fieldData = context.getForField(fieldType);
+            return new HasChildQueryBuilder.LateParsingQuery(childFilter, innerQuery,
+                HasChildQueryBuilder.DEFAULT_MIN_CHILDREN, HasChildQueryBuilder.DEFAULT_MAX_CHILDREN,
+                fieldType.name(), score ? ScoreMode.Max : ScoreMode.None, fieldData, context.getSearchSimilarity());
+        } else {
+            if (ignoreUnmapped) {
+                return new MatchNoDocsQuery();
+            } else {
+                throw new QueryShardException(context, "[" + NAME + "] join field has no parent type configured");
+            }
+        }
+    }
+
+    private Query parentFieldDoToQuery(QueryShardContext context) throws IOException {
         Query innerQuery;
         String[] previousTypes = context.getTypes();
         context.setTypes(type);
@@ -239,7 +270,7 @@ public class HasParentQueryBuilder extends AbstractQueryBuilder<HasParentQueryBu
             innerQuery,
             HasChildQueryBuilder.DEFAULT_MIN_CHILDREN,
             HasChildQueryBuilder.DEFAULT_MAX_CHILDREN,
-            type,
+            ParentFieldMapper.joinField(type),
             score ? ScoreMode.Max : ScoreMode.None,
             fieldData,
             context.getSearchSimilarity());