HSEARCH-4950 Change how nesting/knn checks are performed

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/aggregation/impl/AbstractElasticsearchNestableAggregation.java

@@ -15,6 +15,7 @@
 import org.hibernate.search.backend.elasticsearch.search.common.impl.ElasticsearchSearchIndexScope;
 import org.hibernate.search.backend.elasticsearch.search.common.impl.ElasticsearchSearchIndexValueFieldContext;
 import org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSearchPredicate;
+import org.hibernate.search.backend.elasticsearch.search.predicate.impl.PredicateNestingContext;
 import org.hibernate.search.backend.elasticsearch.search.predicate.impl.PredicateRequestContext;
 import org.hibernate.search.engine.search.predicate.SearchPredicate;
 import org.hibernate.search.util.common.logging.impl.LoggerFactory;
@@ -132,7 +133,8 @@ public void filter(SearchPredicate filter) {
 				throw log.cannotFilterAggregationOnRootDocumentField( field.absolutePath(), field.eventContext() );
 			}
 			ElasticsearchSearchPredicate elasticsearchFilter = ElasticsearchSearchPredicate.from( scope, filter );
-			elasticsearchFilter.checkNestableWithin( nestedPathHierarchy.get( nestedPathHierarchy.size() - 1 ) );
+			elasticsearchFilter.checkNestableWithin(
+					PredicateNestingContext.nested( nestedPathHierarchy.get( nestedPathHierarchy.size() - 1 ) ) );
 			this.filter = elasticsearchFilter;
 		}
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/AbstractElasticsearchNestablePredicate.java

@@ -23,9 +23,11 @@ public abstract class AbstractElasticsearchNestablePredicate extends AbstractEla
 		super( builder );
 	}
 
+
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
+	public void doCheckNestableWithin(PredicateNestingContext context) {
 		List<String> nestedPathHierarchy = getNestedPathHierarchy();
+		String expectedParentNestedPath = context.getNestedPath();
 
 		if ( expectedParentNestedPath != null && !nestedPathHierarchy.contains( expectedParentNestedPath ) ) {
 			throw log.invalidNestedObjectPathForPredicate( this, expectedParentNestedPath,
@@ -34,26 +36,24 @@ public void checkNestableWithin(String expectedParentNestedPath) {
 	}
 
 	@Override
-	public JsonObject buildJsonQuery(PredicateRequestContext context) {
+	public JsonObject toJsonQuery(PredicateRequestContext context) {
 		List<String> nestedPathHierarchy = getNestedPathHierarchy();
 		String expectedNestedPath = nestedPathHierarchy.isEmpty()
 				? null
 				: nestedPathHierarchy.get( nestedPathHierarchy.size() - 1 );
 
 		if ( Objects.equals( context.getNestedPath(), expectedNestedPath ) ) {
 			// Implicit nesting is not necessary
-			checkNestableWithin( context.getNestedPath() );
-			return super.buildJsonQuery( context );
+			return super.toJsonQuery( context );
 		}
 
 		// The context we expect this predicate to be built in.
 		// We'll make sure to wrap it in nested predicates as appropriate in the next few lines,
 		// so that the predicate is actually executed in this context.
 		PredicateRequestContext contextAfterImplicitNesting =
 				context.withNestedPath( expectedNestedPath );
-		checkNestableWithin( expectedNestedPath );
 
-		JsonObject result = super.buildJsonQuery( contextAfterImplicitNesting );
+		JsonObject result = super.toJsonQuery( contextAfterImplicitNesting );
 
 		// traversing the nestedPathHierarchy in the inverted order
 		int hierarchyLastIndex = nestedPathHierarchy.size() - 1;

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/AbstractElasticsearchPredicate.java

@@ -37,7 +37,7 @@ public Set<String> indexNames() {
 	}
 
 	@Override
-	public JsonObject buildJsonQuery(PredicateRequestContext context) {
+	public JsonObject toJsonQuery(PredicateRequestContext context) {
 		JsonObject outerObject = new JsonObject();
 		JsonObject innerObject = new JsonObject();
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchBooleanPredicate.java

@@ -64,11 +64,11 @@ private ElasticsearchBooleanPredicate(Builder builder) {
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
-		checkNestableWithin( expectedParentNestedPath, mustClauses );
-		checkNestableWithin( expectedParentNestedPath, shouldClauses );
-		checkNestableWithin( expectedParentNestedPath, filterClauses );
-		checkNestableWithin( expectedParentNestedPath, mustNotClauses );
+	public void doCheckNestableWithin(PredicateNestingContext context) {
+		checkAcceptableWithin( context, mustClauses );
+		checkAcceptableWithin( context, shouldClauses );
+		checkAcceptableWithin( context, filterClauses );
+		checkAcceptableWithin( context, mustNotClauses );
 	}
 
 	@Override
@@ -126,12 +126,12 @@ private void contributeClauses(PredicateRequestContext context, JsonObject inner
 		}
 	}
 
-	private void checkNestableWithin(String expectedParentNestedPath, List<ElasticsearchSearchPredicate> clauses) {
+	private void checkAcceptableWithin(PredicateNestingContext context, List<ElasticsearchSearchPredicate> clauses) {
 		if ( clauses == null ) {
 			return;
 		}
 		for ( ElasticsearchSearchPredicate clause : clauses ) {
-			clause.checkNestableWithin( expectedParentNestedPath );
+			clause.checkNestableWithin( context );
 		}
 	}
 
@@ -218,31 +218,39 @@ public void must(SearchPredicate clause) {
 			if ( mustClauses == null ) {
 				mustClauses = new ArrayList<>();
 			}
-			mustClauses.add( ElasticsearchSearchPredicate.from( scope, clause ) );
+			ElasticsearchSearchPredicate elasticsearchClause = ElasticsearchSearchPredicate.from( scope, clause );
+			elasticsearchClause.checkNestableWithin( PredicateNestingContext.doesNotAcceptKnn() );
+			mustClauses.add( elasticsearchClause );
 		}
 
 		@Override
 		public void mustNot(SearchPredicate clause) {
 			if ( mustNotClauses == null ) {
 				mustNotClauses = new ArrayList<>();
 			}
-			mustNotClauses.add( ElasticsearchSearchPredicate.from( scope, clause ) );
+			ElasticsearchSearchPredicate elasticsearchClause = ElasticsearchSearchPredicate.from( scope, clause );
+			elasticsearchClause.checkNestableWithin( PredicateNestingContext.doesNotAcceptKnn() );
+			mustNotClauses.add( elasticsearchClause );
 		}
 
 		@Override
 		public void should(SearchPredicate clause) {
 			if ( shouldClauses == null ) {
 				shouldClauses = new ArrayList<>();
 			}
-			shouldClauses.add( ElasticsearchSearchPredicate.from( scope, clause ) );
+			ElasticsearchSearchPredicate elasticsearchClause = ElasticsearchSearchPredicate.from( scope, clause );
+			elasticsearchClause.checkNestableWithin( PredicateNestingContext.acceptsKnn() );
+			shouldClauses.add( elasticsearchClause );
 		}
 
 		@Override
 		public void filter(SearchPredicate clause) {
 			if ( filterClauses == null ) {
 				filterClauses = new ArrayList<>();
 			}
-			filterClauses.add( ElasticsearchSearchPredicate.from( scope, clause ) );
+			ElasticsearchSearchPredicate elasticsearchClause = ElasticsearchSearchPredicate.from( scope, clause );
+			elasticsearchClause.checkNestableWithin( PredicateNestingContext.doesNotAcceptKnn() );
+			filterClauses.add( elasticsearchClause );
 		}
 
 		@Override

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchKnnPredicate.java

@@ -119,7 +119,9 @@ public void vector(Object vector) {
 
 		@Override
 		public void filter(SearchPredicate filter) {
-			this.filter = ElasticsearchSearchPredicate.from( scope, filter );
+			ElasticsearchSearchPredicate elasticsearchFilter = ElasticsearchSearchPredicate.from( scope, filter );
+			elasticsearchFilter.checkNestableWithin( PredicateNestingContext.doesNotAcceptKnn() );
+			this.filter = elasticsearchFilter;
 		}
 
 	}
@@ -157,9 +159,9 @@ private ElasticsearchImpl(Builder<?> builder) {
 		}
 
 		@Override
-		public JsonObject buildJsonQuery(PredicateRequestContext context) {
+		public JsonObject toJsonQuery(PredicateRequestContext context) {
 			// we want the query to get created and passed to the request context
-			context.contributeKnnClause( ( super.buildJsonQuery( context ) ) );
+			context.contributeKnnClause( ( super.toJsonQuery( context ) ) );
 			// but we don't want it to be an actual query so we return `null`:
 			return null;
 		}
@@ -181,8 +183,8 @@ protected JsonObject doToJsonQuery(PredicateRequestContext context, JsonObject o
 		}
 
 		@Override
-		public void checkNestableWithin(String expectedParentNestedPath) {
-			if ( expectedParentNestedPath != null ) {
+		public void doCheckNestableWithin(PredicateNestingContext context) {
+			if ( context.getNestedPath() != null || !context.acceptsKnnClause() ) {
 				throw log.cannotAddKnnClauseAtThisStep();
 			}
 		}

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchMatchAllPredicate.java

@@ -23,7 +23,7 @@ private ElasticsearchMatchAllPredicate(Builder builder) {
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
+	public void doCheckNestableWithin(PredicateNestingContext context) {
 		// Nothing to do
 	}
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchMatchIdPredicate.java

@@ -59,7 +59,7 @@ private ElasticsearchMatchIdPredicate(Builder builder) {
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
+	public void doCheckNestableWithin(PredicateNestingContext context) {
 		// Nothing to do
 	}
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchMatchNonePredicate.java

@@ -24,7 +24,7 @@ class ElasticsearchMatchNonePredicate extends AbstractElasticsearchPredicate {
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
+	public void doCheckNestableWithin(PredicateNestingContext context) {
 		// Nothing to do
 	}
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchNamedPredicate.java

@@ -38,9 +38,9 @@ private ElasticsearchNamedPredicate(Builder builder, ElasticsearchSearchPredicat
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
-		providedPredicate.checkNestableWithin( expectedParentNestedPath );
-		super.checkNestableWithin( expectedParentNestedPath );
+	public void doCheckNestableWithin(PredicateNestingContext context) {
+		providedPredicate.checkNestableWithin( context );
+		super.checkNestableWithin( context );
 	}
 
 	@Override

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchNestedPredicate.java

@@ -77,7 +77,7 @@ private static class Builder extends AbstractBuilder implements NestedPredicateB
 		public void nested(SearchPredicate nestedPredicate) {
 			ElasticsearchSearchPredicate elasticsearchPredicate = ElasticsearchSearchPredicate.from(
 					scope, nestedPredicate );
-			elasticsearchPredicate.checkNestableWithin( absoluteFieldPath );
+			elasticsearchPredicate.checkNestableWithin( PredicateNestingContext.nested( absoluteFieldPath ) );
 			this.nestedPredicate = elasticsearchPredicate;
 		}
 

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchSearchPredicate.java

@@ -22,13 +22,13 @@ public abstract class ElasticsearchSearchPredicate implements SearchPredicate {
 
 	public abstract Set<String> indexNames();
 
-	public abstract void checkNestableWithin(String expectedParentNestedPath);
-
-	public final JsonObject toJsonQuery(PredicateRequestContext context) {
-		return buildJsonQuery( context.predicateContext( this ) );
+	public final void checkNestableWithin(PredicateNestingContext context) {
+		doCheckNestableWithin( context.wrap( this ) );
 	}
 
-	public abstract JsonObject buildJsonQuery(PredicateRequestContext context);
+	protected abstract void doCheckNestableWithin(PredicateNestingContext context);
+
+	public abstract JsonObject toJsonQuery(PredicateRequestContext context);
 
 	public static ElasticsearchSearchPredicate from(ElasticsearchSearchIndexScope<?> scope, SearchPredicate predicate) {
 		if ( !( predicate instanceof ElasticsearchSearchPredicate ) ) {

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/ElasticsearchUserProvidedJsonPredicate.java

@@ -29,12 +29,12 @@ public Set<String> indexNames() {
 	}
 
 	@Override
-	public void checkNestableWithin(String expectedParentNestedPath) {
+	public void doCheckNestableWithin(PredicateNestingContext context) {
 		// Nothing to do: we'll assume the user knows what they are doing.
 	}
 
 	@Override
-	public JsonObject buildJsonQuery(PredicateRequestContext context) {
+	public JsonObject toJsonQuery(PredicateRequestContext context) {
 		return json;
 	}
 }

backend/elasticsearch/src/main/java/org/hibernate/search/backend/elasticsearch/search/predicate/impl/PredicateNestingContext.java

@@ -0,0 +1,63 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.backend.elasticsearch.search.predicate.impl;
+
+public class PredicateNestingContext {
+	private static final PredicateNestingContext ACCEPTS_KNN = new PredicateNestingContext( true );
+	private static final PredicateNestingContext DOES_NOT_ACCEPT_KNN = new PredicateNestingContext( false );
+	private final String nestedPath;
+	private final boolean acceptsKnnClause;
+
+	private final Class<? extends ElasticsearchSearchPredicate> predicateType;
+
+	public static PredicateNestingContext acceptsKnn() {
+		return ACCEPTS_KNN;
+	}
+
+	public static PredicateNestingContext doesNotAcceptKnn() {
+		return DOES_NOT_ACCEPT_KNN;
+	}
+
+	public static PredicateNestingContext nested(String nestedPath) {
+		return new PredicateNestingContext( nestedPath );
+	}
+
+	private PredicateNestingContext(String nestedPath, boolean acceptsKnnClause) {
+		this( nestedPath, acceptsKnnClause, null );
+	}
+
+	private PredicateNestingContext(String nestedPath, boolean acceptsKnnClause,
+			Class<? extends ElasticsearchSearchPredicate> predicateType) {
+		this.nestedPath = nestedPath;
+		this.acceptsKnnClause = acceptsKnnClause;
+		this.predicateType = predicateType;
+	}
+
+	private PredicateNestingContext(String nestedPath) {
+		this( nestedPath, false );
+	}
+
+	private PredicateNestingContext(boolean acceptsKnnClause) {
+		this( null, acceptsKnnClause );
+	}
+
+	public String getNestedPath() {
+		return nestedPath;
+	}
+
+	public boolean acceptsKnnClause() {
+		return acceptsKnnClause;
+	}
+
+	public PredicateNestingContext wrap(ElasticsearchSearchPredicate elasticsearchSearchPredicate) {
+		return new PredicateNestingContext(
+				nestedPath,
+				acceptsKnnClause && this.predicateType == null,
+				elasticsearchSearchPredicate.getClass()
+		);
+	}
+}