1 files changed, 59 insertions, 0 deletions
diff --git a/config-model/src/main/java/com/yahoo/schema/processing/DynamicSummaryTransformUtils.java b/config-model/src/main/java/com/yahoo/schema/processing/DynamicSummaryTransformUtils.java
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index 00000000000..20597eca64f
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+++ b/config-model/src/main/java/com/yahoo/schema/processing/DynamicSummaryTransformUtils.java
@@ -0,0 +1,59 @@
+package com.yahoo.schema.processing;
+
+import com.yahoo.document.DataType;
+import com.yahoo.vespa.documentmodel.SummaryField;
+
+/**
+ * This class contains utils used when handling summary fields with dynamic transforms during processing and deriving.
+ *
+ * Originally (before Vespa 8.52), dynamic transforms where only supported for string fields.
+ * Due to legacy functionality in the backend docsum framework,
+ * such summary fields are in some cases added as extra document fields and populated in indexing scripts.
+ * This is something we want to avoid in the future, but it might not be entirely possible before Vespa 9.
+ *
+ * With the introduction of dynamic transform for array of string fields,
+ * we move in the right direction and avoid adding extra document fields with indexing script population for this type.
+ * Instead, we configure the dynamic transform in the backend to use the original source field directly.
+ *
+ * See SummaryTransform.isDynamic() for which transforms this applies to.
+ */
+public class DynamicSummaryTransformUtils {
+
+    public static boolean hasSupportedType(SummaryField field) {
+        return isSupportedType(field.getDataType());
+    }
+
+    public static boolean isSupportedType(DataType type) {
+        return isOriginalSupportedType(type) || isNewSupportedType(type);
+    }
+
+    private static boolean isOriginalSupportedType(DataType type) {
+        return (type == DataType.STRING) ||
+                (type == DataType.URI);
+    }
+
+    private static boolean isNewSupportedType(DataType type) {
+        return (type.equals(DataType.getArray(DataType.STRING)));
+    }
+
+    /**
+     * Whether a summary field must be populated by the source field with the given type in an indexing script.
+     */
+    public static boolean summaryFieldIsPopulatedBySourceField(DataType sourceFieldType) {
+        return isOriginalSupportedType(sourceFieldType);
+    }
+
+    /**
+     * Whether a summary field is required as an extra field in the document type.
+     */
+    public static boolean summaryFieldIsRequiredInDocumentType(SummaryField summaryField) {
+        return summaryFieldIsPopulatedBySourceField(summaryField.getDataType());
+    }
+
+    public static String getSource(SummaryField summaryField) {
+        // Summary fields with the original supported type is always present in the document type,
+        // and we must use that field as source at run-time.
+        return isOriginalSupportedType(summaryField.getDataType()) ?
+                summaryField.getName() : summaryField.getSingleSource();
+    }
+}