ESQL: Move some of ENRICH into compute (#116338) (#116424)

* ESQL: Move some of ENRICH into compute

Move much of the code powering ENRICH and LOOKUP from index into the
`compute` project which has better support for testing `Operator`s.

This is *almost* just a move - except that I had to change the way
`QueryList` looks at `DataType` - because `compute` doesn't have
`DataType`. Instead I've moved the places where we used `DataType` into
method calls. I haven't changed how anything works in the tight loop -
but I have changed how it works in the setup.

* Do better

* Rename

* Drop extra

x-pack/plugin/esql/build.gradle

@@ -289,34 +289,6 @@ tasks.named('stringTemplates').configure {
   var doubleProperties = prop("Double", "double", "DOUBLE", "Double.BYTES", "DoubleArray")
   var bytesRefProperties = prop("BytesRef", "BytesRef", "BYTES_REF", "org.apache.lucene.util.RamUsageEstimator.NUM_BYTES_OBJECT_REF", "")
   var booleanProperties = prop("Boolean", "boolean", "BOOLEAN", "Byte.BYTES", "BitArray")
-  // enrich
-  File enrichResultBuilderInput = file("src/main/java/org/elasticsearch/xpack/esql/enrich/X-EnrichResultBuilder.java.st")
-  template {
-    it.properties = intProperties
-    it.inputFile = enrichResultBuilderInput
-    it.outputFile = "org/elasticsearch/xpack/esql/enrich/EnrichResultBuilderForInt.java"
-  }
-  template {
-    it.properties = longProperties
-    it.inputFile = enrichResultBuilderInput
-    it.outputFile = "org/elasticsearch/xpack/esql/enrich/EnrichResultBuilderForLong.java"
-  }
-  template {
-    it.properties = doubleProperties
-    it.inputFile = enrichResultBuilderInput
-    it.outputFile = "org/elasticsearch/xpack/esql/enrich/EnrichResultBuilderForDouble.java"
-  }
-  template {
-    it.properties = bytesRefProperties
-    it.inputFile = enrichResultBuilderInput
-    it.outputFile = "org/elasticsearch/xpack/esql/enrich/EnrichResultBuilderForBytesRef.java"
-  }
-  template {
-    it.properties = booleanProperties
-    it.inputFile = enrichResultBuilderInput
-    it.outputFile = "org/elasticsearch/xpack/esql/enrich/EnrichResultBuilderForBoolean.java"
-  }
-
 
   File inInputFile = file("src/main/java/org/elasticsearch/xpack/esql/expression/predicate/operator/comparison/X-InEvaluator.java.st")
   template {

x-pack/plugin/esql/compute/build.gradle

@@ -803,4 +803,32 @@ tasks.named('stringTemplates').configure {
     it.inputFile = bucketedSortInputFile
     it.outputFile = "org/elasticsearch/compute/data/sort/DoubleBucketedSort.java"
   }
+
+  File enrichResultBuilderInput = file("src/main/java/org/elasticsearch/compute/operator/lookup/X-EnrichResultBuilder.java.st")
+  template {
+    it.properties = intProperties
+    it.inputFile = enrichResultBuilderInput
+    it.outputFile = "org/elasticsearch/xpack/compute/operator/lookup/EnrichResultBuilderForInt.java"
+  }
+  template {
+    it.properties = longProperties
+    it.inputFile = enrichResultBuilderInput
+    it.outputFile = "org/elasticsearch/xpack/compute/operator/lookup/EnrichResultBuilderForLong.java"
+  }
+  template {
+    it.properties = doubleProperties
+    it.inputFile = enrichResultBuilderInput
+    it.outputFile = "org/elasticsearch/xpack/compute/operator/lookup/EnrichResultBuilderForDouble.java"
+  }
+  template {
+    it.properties = bytesRefProperties
+    it.inputFile = enrichResultBuilderInput
+    it.outputFile = "org/elasticsearch/xpack/compute/operator/lookup/EnrichResultBuilderForBytesRef.java"
+  }
+  template {
+    it.properties = booleanProperties
+    it.inputFile = enrichResultBuilderInput
+    it.outputFile = "org/elasticsearch/xpack/compute/operator/lookup/EnrichResultBuilderForBoolean.java"
+  }
+
 }

x-pack/plugin/esql/compute/src/main/java/module-info.java

@@ -29,6 +29,7 @@
     exports org.elasticsearch.compute.operator.exchange;
     exports org.elasticsearch.compute.aggregation.blockhash;
     exports org.elasticsearch.compute.aggregation.spatial;
+    exports org.elasticsearch.compute.operator.lookup;
     exports org.elasticsearch.compute.operator.topn;
     exports org.elasticsearch.compute.operator.mvdedupe;
     exports org.elasticsearch.compute.aggregation.table;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/enrich/EnrichQuerySourceOperator.java → x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/lookup/EnrichQuerySourceOperator.java

@@ -5,7 +5,7 @@
  * 2.0.
  */
 
-package org.elasticsearch.xpack.esql.enrich;
+package org.elasticsearch.compute.operator.lookup;
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReaderContext;
@@ -31,8 +31,7 @@
  * This operator will emit Pages consisting of a {@link DocVector} and {@link IntBlock} of positions for each query of the input queries.
  * The position block will be used as keys to combine the extracted values by {@link MergePositionsOperator}.
  */
-final class EnrichQuerySourceOperator extends SourceOperator {
-
+public final class EnrichQuerySourceOperator extends SourceOperator {
     private final BlockFactory blockFactory;
     private final QueryList queryList;
     private int queryPosition = -1;
@@ -41,9 +40,9 @@ final class EnrichQuerySourceOperator extends SourceOperator {
     private final int maxPageSize;
 
     // using smaller pages enables quick cancellation and reduces sorting costs
-    static final int DEFAULT_MAX_PAGE_SIZE = 256;
+    public static final int DEFAULT_MAX_PAGE_SIZE = 256;
 
-    EnrichQuerySourceOperator(BlockFactory blockFactory, int maxPageSize, QueryList queryList, IndexReader indexReader) {
+    public EnrichQuerySourceOperator(BlockFactory blockFactory, int maxPageSize, QueryList queryList, IndexReader indexReader) {
         this.blockFactory = blockFactory;
         this.maxPageSize = maxPageSize;
         this.queryList = queryList;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/enrich/EnrichResultBuilder.java → x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/lookup/EnrichResultBuilder.java

@@ -5,7 +5,7 @@
  * 2.0.
  */
 
-package org.elasticsearch.xpack.esql.enrich;
+package org.elasticsearch.compute.operator.lookup;
 
 import org.elasticsearch.compute.data.Block;
 import org.elasticsearch.compute.data.BlockFactory;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/enrich/MergePositionsOperator.java → x-pack/plugin/esql/compute/src/main/java/org/elasticsearch/compute/operator/lookup/MergePositionsOperator.java

@@ -5,7 +5,7 @@
  * 2.0.
  */
 
-package org.elasticsearch.xpack.esql.enrich;
+package org.elasticsearch.compute.operator.lookup;
 
 import org.elasticsearch.compute.data.Block;
 import org.elasticsearch.compute.data.BlockFactory;
@@ -43,15 +43,15 @@
  * |  null      | null       |
  * |  d         | 2023       |
  */
-final class MergePositionsOperator implements Operator {
+public final class MergePositionsOperator implements Operator {
     private boolean finished = false;
     private final int positionChannel;
     private final EnrichResultBuilder[] builders;
     private final IntBlock selectedPositions;
 
     private Page outputPage;
 
-    MergePositionsOperator(
+    public MergePositionsOperator(
         int positionChannel,
         int[] mergingChannels,
         ElementType[] mergingTypes,