Allow unsigned long field to use decay functions (#96394)

This change adds support for unsigned long fields (and any fields that can provide numeric data) to use decay functions as described by (#89603). This allows mapped fields developed as plugins to also have access to this set of functions provided they return IndexNumericFieldData from getForField. Closes #89603.

Author: jdconrad

docs/changelog/96394.yaml

@@ -0,0 +1,6 @@
+pr: 96394
+summary: Allow unsigned long field to use decay functions
+area: Mapping
+type: enhancement
+issues:
+ - 89603

server/src/main/java/org/elasticsearch/index/query/functionscore/DecayFunctionBuilder.java

@@ -26,6 +26,7 @@
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.index.fielddata.FieldData;
+import org.elasticsearch.index.fielddata.IndexFieldData;
 import org.elasticsearch.index.fielddata.IndexGeoPointFieldData;
 import org.elasticsearch.index.fielddata.IndexNumericFieldData;
 import org.elasticsearch.index.fielddata.MultiGeoPointValues;
@@ -35,7 +36,6 @@
 import org.elasticsearch.index.mapper.DateFieldMapper;
 import org.elasticsearch.index.mapper.GeoPointFieldMapper.GeoPointFieldType;
 import org.elasticsearch.index.mapper.MappedFieldType;
-import org.elasticsearch.index.mapper.NumberFieldMapper;
 import org.elasticsearch.index.query.SearchExecutionContext;
 import org.elasticsearch.search.MultiValueMode;
 import org.elasticsearch.xcontent.NamedXContentRegistry;
@@ -217,15 +217,8 @@ private AbstractDistanceScoreFunction parseVariable(
  return parseDateVariable(parser, context, fieldType, mode);
  } else if (fieldType instanceof GeoPointFieldType) {
  return parseGeoVariable(parser, context, fieldType, mode);
- } else if (fieldType instanceof NumberFieldMapper.NumberFieldType) {
- return parseNumberVariable(parser, context, fieldType, mode);
  } else {
- throw new ParsingException(
- parser.getTokenLocation(),
- "field [{}] is of type [{}], but only numeric types are supported.",
- fieldName,
- fieldType
- );
+ return parseNumberVariable(parser, context, fieldType, mode);
  }
  }
 
@@ -267,8 +260,15 @@ private AbstractDistanceScoreFunction parseNumberVariable(
  DecayFunctionBuilder.ORIGIN
  );
  }
- IndexNumericFieldData numericFieldData = context.getForField(fieldType, MappedFieldType.FielddataOperation.SEARCH);
- return new NumericFieldDataScoreFunction(origin, scale, decay, offset, getDecayFunction(), numericFieldData, mode);
+
+ IndexFieldData<?> indexFieldData = context.getForField(fieldType, MappedFieldType.FielddataOperation.SEARCH);
+ if (indexFieldData instanceof IndexNumericFieldData numericFieldData) {
+ return new NumericFieldDataScoreFunction(origin, scale, decay, offset, getDecayFunction(), numericFieldData, mode);
+ } else {
+ throw new IllegalArgumentException(
+ "field [" + fieldName + "] is of type [" + fieldType + "], but only numeric types are supported."
+ );
+ }
  }
 
  private AbstractDistanceScoreFunction parseGeoVariable(

x-pack/plugin/mapper-unsigned-long/src/yamlRestTest/resources/rest-api-spec/test/10_basic.yml

@@ -376,3 +376,32 @@ setup:
  }]
 
  - length: { aggregations.test.buckets: 0 }
+
+---
+"Decay":
+ - skip:
+ features: close_to
+ version: " - 8.8.99"
+ reason: "decay functions not supported for unsigned_long"
+
+ - do:
+ search:
+ index: test1
+ body:
+ size: 10
+ query:
+ function_score:
+ functions: [{
+ "linear": {
+ "ul": {
+ "scale": 18000000000000000000.0,
+ "origin": 12000000000000000000.0
+ }
+ }
+ }]
+
+ - close_to: { hits.hits.0._score: { value: 0.9228715, error: 0.001 } }
+ - close_to: { hits.hits.1._score: { value: 0.9228715, error: 0.001 } }
+ - close_to: { hits.hits.2._score: { value: 0.8209238, error: 0.001 } }
+ - close_to: { hits.hits.3._score: { value: 0.8209238, error: 0.001 } }
+ - close_to: { hits.hits.4._score: { value: 0.6666667, error: 0.001 } }