SQL: Remove empty interface (elastic/x-pack-elasticsearch#3564)

After some recent changes this interface is now empty.

Original commit: elastic/x-pack-elasticsearch@4a44812f78

sql/server/src/main/java/org/elasticsearch/xpack/sql/execution/search/Scroller.java

@@ -36,7 +36,6 @@ import org.elasticsearch.xpack.sql.expression.function.scalar.processor.definiti
 import org.elasticsearch.xpack.sql.expression.function.scalar.processor.runtime.Processor;
 import org.elasticsearch.xpack.sql.querydsl.agg.AggPath;
 import org.elasticsearch.xpack.sql.querydsl.container.AggRef;
-import org.elasticsearch.xpack.sql.querydsl.container.ColumnReference;
 import org.elasticsearch.xpack.sql.querydsl.container.ComputedRef;
 import org.elasticsearch.xpack.sql.querydsl.container.QueryContainer;
 import org.elasticsearch.xpack.sql.querydsl.container.ScriptFieldRef;
@@ -115,9 +114,9 @@ public class Scroller {
             // this method assumes the nested aggregation are all part of the same tree (the SQL group-by)
             int maxDepth = -1;
 
-            List<ColumnReference> cols = query.columns();
+            List<FieldExtraction> cols = query.columns();
             for (int index = 0; index < cols.size(); index++) {
-                ColumnReference col = cols.get(index);
+                FieldExtraction col = cols.get(index);
                 Supplier<Object> supplier = null;
 
                 if (col instanceof ComputedRef) {
@@ -157,7 +156,7 @@ public class Scroller {
                     listener::onFailure));
         }
 
-        private Object[] extractAggValue(ColumnReference col, SearchResponse response) {
+        private Object[] extractAggValue(FieldExtraction col, SearchResponse response) {
             if (col == TotalCountRef.INSTANCE) {
                 return new Object[] { Long.valueOf(response.getHits().getTotalHits()) };
             }
@@ -254,17 +253,17 @@ public class Scroller {
 
         private List<HitExtractor> getExtractors() {
             // create response extractors for the first time
-            List<ColumnReference> refs = query.columns();
+            List<FieldExtraction> refs = query.columns();
 
             List<HitExtractor> exts = new ArrayList<>(refs.size());
 
-            for (ColumnReference ref : refs) {
+            for (FieldExtraction ref : refs) {
                 exts.add(createExtractor(ref));
             }
             return exts;
         }
 
-        private HitExtractor createExtractor(ColumnReference ref) {
+        private HitExtractor createExtractor(FieldExtraction ref) {
             if (ref instanceof SearchHitFieldRef) {
                 SearchHitFieldRef f = (SearchHitFieldRef) ref;
                 return new FieldHitExtractor(f.name(), f.useDocValue(), f.hitName());

sql/server/src/main/java/org/elasticsearch/xpack/sql/expression/function/scalar/processor/definition/ProcessorDefinition.java

@@ -9,7 +9,6 @@ import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.expression.Attribute;
 import org.elasticsearch.xpack.sql.expression.Expression;
 import org.elasticsearch.xpack.sql.expression.function.scalar.processor.runtime.Processor;
-import org.elasticsearch.xpack.sql.querydsl.container.ColumnReference;
 import org.elasticsearch.xpack.sql.tree.Node;
 
 import java.util.List;
@@ -33,13 +32,13 @@ public abstract class ProcessorDefinition extends Node<ProcessorDefinition> impl
 
     /**
      * Resolve {@link Attribute}s which are unprocessable into
-     * {@link ColumnReference}s which are processable.
+     * {@link FieldExtraction}s which are processable.
      *
      * @return {@code this} if the resolution doesn't change the
      *      definition, a new {@link ProcessorDefinition} otherwise
      */
     public abstract ProcessorDefinition resolveAttributes(AttributeResolver resolver);
     public interface AttributeResolver {
-        ColumnReference resolve(Attribute attribute);
+        FieldExtraction resolve(Attribute attribute);
     }
 }

sql/server/src/main/java/org/elasticsearch/xpack/sql/expression/function/scalar/processor/definition/ReferenceInput.java

@@ -5,12 +5,12 @@
  */
 package org.elasticsearch.xpack.sql.expression.function.scalar.processor.definition;
 
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.execution.search.SqlSourceBuilder;
 import org.elasticsearch.xpack.sql.expression.Expression;
-import org.elasticsearch.xpack.sql.querydsl.container.ColumnReference;
 
-public class ReferenceInput extends NonExecutableInput<ColumnReference> {
+public class ReferenceInput extends NonExecutableInput<FieldExtraction> {
-    public ReferenceInput(Expression expression, ColumnReference context) {
+    public ReferenceInput(Expression expression, FieldExtraction context) {
         super(expression, context);
     }
 

sql/server/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/AggRef.java

@@ -5,10 +5,11 @@
  */
 package org.elasticsearch.xpack.sql.querydsl.container;
 
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.execution.search.SqlSourceBuilder;
 import org.elasticsearch.xpack.sql.querydsl.agg.AggPath;
 
-public class AggRef implements ColumnReference {
+public class AggRef implements FieldExtraction {
     private final String path;
     private final int depth;
 

sql/server/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/ColumnReference.java

@@ -1,17 +0,0 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License;
- * you may not use this file except in compliance with the Elastic License.
- */
-package org.elasticsearch.xpack.sql.querydsl.container;
-
-import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
-
-/**
- * Entity representing a 'column' backed by one or multiple results from ES. A
- * column reference can also extract a field (meta or otherwise) from a result
- * set, so extends {@link FieldExtraction}.
- */
-public interface ColumnReference extends FieldExtraction {
-    // TODO remove this interface intirely in a followup
-}

sql/server/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/ComputedRef.java

@@ -5,10 +5,11 @@
  */
 package org.elasticsearch.xpack.sql.querydsl.container;
 
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.execution.search.SqlSourceBuilder;
 import org.elasticsearch.xpack.sql.expression.function.scalar.processor.definition.ProcessorDefinition;
 
-public class ComputedRef implements ColumnReference {
+public class ComputedRef implements FieldExtraction {
 
     private final ProcessorDefinition processor;
 

sql/server/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/FieldReference.java

@@ -5,7 +5,9 @@
  */
 package org.elasticsearch.xpack.sql.querydsl.container;
 
-public abstract class FieldReference implements ColumnReference {
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
+
+public abstract class FieldReference implements FieldExtraction {
     /**
      * Field name.
      *

sql/server/src/main/java/org/elasticsearch/xpack/sql/querydsl/container/QueryContainer.java

@@ -11,6 +11,7 @@ import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.xpack.sql.SqlIllegalArgumentException;
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.execution.search.SourceGenerator;
 import org.elasticsearch.xpack.sql.expression.Attribute;
 import org.elasticsearch.xpack.sql.expression.FieldAttribute;
@@ -55,7 +56,7 @@ public class QueryContainer {
 
     // final output seen by the client (hence the list or ordering)
     // gets converted by the Scroller into Extractors for hits or actual results in case of aggregations
-    private final List<ColumnReference> columns;
+    private final List<FieldExtraction> columns;
 
     // aliases (maps an alias to its actual resolved attribute)
     private final Map<Attribute, Attribute> aliases;
@@ -78,7 +79,7 @@ public class QueryContainer {
         this(null, null, null, null, null, null, null, -1);
     }
 
-    public QueryContainer(Query query, Aggs aggs, List<ColumnReference> refs, Map<Attribute, Attribute> aliases,
+    public QueryContainer(Query query, Aggs aggs, List<FieldExtraction> refs, Map<Attribute, Attribute> aliases,
             Map<String, GroupingAgg> pseudoFunctions,
             Map<Attribute, ProcessorDefinition> scalarFunctions,
             Set<Sort> sort, int limit) {
@@ -90,8 +91,8 @@ public class QueryContainer {
         this.columns = refs == null || refs.isEmpty() ? emptyList() : refs;
         this.sort = sort == null || sort.isEmpty() ? emptySet() : sort;
         this.limit = limit;
-        aggsOnly = columns.stream().allMatch(ColumnReference::supportedByAggsOnlyQuery);
+        aggsOnly = columns.stream().allMatch(FieldExtraction::supportedByAggsOnlyQuery);
-        aggDepth = columns.stream().mapToInt(ColumnReference::depth).max().orElse(0);
+        aggDepth = columns.stream().mapToInt(FieldExtraction::depth).max().orElse(0);
     }
 
     public Query query() {
@@ -102,7 +103,7 @@ public class QueryContainer {
         return aggs;
     }
 
-    public List<ColumnReference> columns() {
+    public List<FieldExtraction> columns() {
         return columns;
     }
 
@@ -142,7 +143,7 @@ public class QueryContainer {
         return new QueryContainer(q, aggs, columns, aliases, pseudoFunctions, scalarFunctions, sort, limit);
     }
 
-    public QueryContainer with(List<ColumnReference> r) {
+    public QueryContainer with(List<FieldExtraction> r) {
         return new QueryContainer(query, aggs, r, aliases, pseudoFunctions, scalarFunctions, sort, limit);
     }
 
@@ -179,13 +180,13 @@ public class QueryContainer {
     //
     // reference methods
     //
-    private ColumnReference searchHitFieldRef(FieldAttribute fieldAttr) {
+    private FieldExtraction searchHitFieldRef(FieldAttribute fieldAttr) {
         return new SearchHitFieldRef(aliasName(fieldAttr), fieldAttr.dataType().hasDocValues());
     }
 
-    private Tuple<QueryContainer, ColumnReference> nestedFieldRef(FieldAttribute attr) {
+    private Tuple<QueryContainer, FieldExtraction> nestedFieldRef(FieldAttribute attr) {
         // Find the nested query for this field. If there isn't one then create it
-        List<ColumnReference> nestedRefs = new ArrayList<>();
+        List<FieldExtraction> nestedRefs = new ArrayList<>();
 
         Query q = rewriteToContainNestedField(query, attr.location(),
             attr.nestedParent().path(), aliasName(attr), attr.dataType().hasDocValues());
@@ -221,7 +222,7 @@ public class QueryContainer {
     }
 
     // replace function's input with references
-    private Tuple<QueryContainer, ColumnReference> computingRef(ScalarFunctionAttribute sfa) {
+    private Tuple<QueryContainer, FieldExtraction> computingRef(ScalarFunctionAttribute sfa) {
         Attribute name = aliases.getOrDefault(sfa, sfa);
         ProcessorDefinition proc = scalarFunctions.get(name);
 
@@ -243,9 +244,9 @@ public class QueryContainer {
             }
 
             @Override
-            public ColumnReference resolve(Attribute attribute) {
+            public FieldExtraction resolve(Attribute attribute) {
                 Attribute attr = aliases.getOrDefault(attribute, attribute);
-                Tuple<QueryContainer, ColumnReference> ref = container.toReference(attr);
+                Tuple<QueryContainer, FieldExtraction> ref = container.toReference(attr);
                 container = ref.v1();
                 return ref.v2();
             }
@@ -262,11 +263,11 @@ public class QueryContainer {
     }
 
     public QueryContainer addColumn(Attribute attr) {
-        Tuple<QueryContainer, ColumnReference> tuple = toReference(attr);
+        Tuple<QueryContainer, FieldExtraction> tuple = toReference(attr);
         return tuple.v1().addColumn(tuple.v2());
     }
 
-    private Tuple<QueryContainer, ColumnReference> toReference(Attribute attr) {
+    private Tuple<QueryContainer, FieldExtraction> toReference(Attribute attr) {
         if (attr instanceof FieldAttribute) {
             FieldAttribute fa = (FieldAttribute) attr;
             if (fa.isNested()) {
@@ -288,7 +289,7 @@ public class QueryContainer {
         throw new SqlIllegalArgumentException("Unknown output attribute %s", attr);
     }
 
-    public QueryContainer addColumn(ColumnReference ref) {
+    public QueryContainer addColumn(FieldExtraction ref) {
         return with(combine(columns, ref));
     }
 
@@ -304,7 +305,7 @@ public class QueryContainer {
     }
 
     public QueryContainer addAggCount(GroupingAgg parentGroup, String functionId) {
-        ColumnReference ref = parentGroup == null ? TotalCountRef.INSTANCE : new AggRef(AggPath.bucketCount(parentGroup.asParentPath()));
+        FieldExtraction ref = parentGroup == null ? TotalCountRef.INSTANCE : new AggRef(AggPath.bucketCount(parentGroup.asParentPath()));
         Map<String, GroupingAgg> pseudoFunctions = new LinkedHashMap<>(this.pseudoFunctions);
         pseudoFunctions.put(functionId, parentGroup);
         return new QueryContainer(query, aggs, combine(columns, ref), aliases, pseudoFunctions, scalarFunctions, sort, limit);

sql/server/src/test/java/org/elasticsearch/xpack/sql/expression/function/scalar/processor/definition/AttributeInputTests.java

@@ -6,15 +6,15 @@
 package org.elasticsearch.xpack.sql.expression.function.scalar.processor.definition;
 
 import org.elasticsearch.test.ESTestCase;
+import org.elasticsearch.xpack.sql.execution.search.FieldExtraction;
 import org.elasticsearch.xpack.sql.expression.Attribute;
 import org.elasticsearch.xpack.sql.expression.Expression;
-import org.elasticsearch.xpack.sql.querydsl.container.ColumnReference;
 
 import static org.mockito.Mockito.mock;
 
 public class AttributeInputTests extends ESTestCase {
     public void testResolveAttributes() {
-        ColumnReference column = mock(ColumnReference.class);
+        FieldExtraction column = mock(FieldExtraction.class);
         Expression expression = mock(Expression.class);
         Attribute attribute = mock(Attribute.class);