Script: ulong via fields API

modules/lang-painless/src/main/resources/org/elasticsearch/painless/org.elasticsearch.script.fields.txt

@@ -10,10 +10,18 @@
 
 # API
 class org.elasticsearch.script.Field {
+  org.elasticsearch.script.Converter BigInteger
+  org.elasticsearch.script.Converter Long
   String getName()
   boolean isEmpty()
   List getValues()
   def getValue(def)
+  double getDouble(double)
+  long getLong(long)
+  org.elasticsearch.script.Field as(org.elasticsearch.script.Converter)
+}
+
+class org.elasticsearch.script.Converter {
 }
 
 class org.elasticsearch.script.DocBasedScript {

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/40_fields_api.yml

@@ -158,3 +158,69 @@ setup:
                     script: "field('sval.keyword').getValue('b') == 'a'"
     - match: { hits.total: 1 }
     - match: { hits.hits.0._id: d3 }
+
+---
+"missing field":
+    - do:
+        indices.create:
+          index: test
+          body:
+            settings:
+              number_of_shards: 2
+            mappings:
+              properties:
+                dval:
+                  type: double
+    - do:
+        index:
+          index: test
+          id: d1
+          body: {"foo": 25, "dval": 1.0 }
+    - do:
+        index:
+          index: test
+          id: d2
+          body: {"foo": 9223372036854775807, "dval": 2.0 }
+    - do:
+        index:
+          index: test
+          id: d3
+          body: { "bar": "abc", "dval": 3.0 }
+    - do:
+        indices.refresh: {}
+    - do:
+        search:
+          rest_total_hits_as_int: true
+          index: test
+          body:
+            query: { "match_all": {} }
+            sort: [ { dval: asc } ]
+            script_fields:
+              missing_field:
+                script:
+                  source: "field('foo').as(Field.BigInteger).getValue(BigInteger.TEN).add(BigInteger.ONE)"
+    - match: { hits.total: 3 }
+    - match: { hits.hits.0._id: d1 }
+    - match: { hits.hits.0.fields.missing_field.0: 26 }
+    - match: { hits.hits.1._id: d2 }
+    - match: { hits.hits.1.fields.missing_field.0: 9223372036854775808 }
+    - match: { hits.hits.2._id: d3 }
+    - match: { hits.hits.2.fields.missing_field.0: 11 }
+    - do:
+        search:
+          rest_total_hits_as_int: true
+          index: test
+          body:
+            query: { "match_all": {} }
+            sort: [ { dval: asc } ]
+            script_fields:
+              missing_field:
+                script:
+                  source: "field('foo').as(Field.BigInteger).as(Field.Long).getValue(10L) + 2L"
+    - match: { hits.total: 3 }
+    - match: { hits.hits.0._id: d1 }
+    - match: { hits.hits.0.fields.missing_field.0: 27 }
+    - match: { hits.hits.1._id: d2 }
+    - match: { hits.hits.1.fields.missing_field.0: -9223372036854775809 }
+    - match: { hits.hits.2._id: d3 }
+    - match: { hits.hits.2.fields.missing_field.0: 12 }

server/src/main/java/org/elasticsearch/index/fielddata/ScriptDocValues.java

@@ -17,6 +17,9 @@
 import org.elasticsearch.common.geo.GeoUtils;
 import org.elasticsearch.common.time.DateUtils;
 import org.elasticsearch.geometry.utils.Geohash;
+import org.elasticsearch.script.Field;
+import org.elasticsearch.script.FieldValues;
+import org.elasticsearch.script.InvalidConversion;
 import org.elasticsearch.script.JodaCompatibleZonedDateTime;
 
 import java.io.IOException;
@@ -25,6 +28,8 @@
 import java.util.AbstractList;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
 import java.util.function.UnaryOperator;
 
 /**
@@ -35,7 +40,7 @@
  * return as a single {@link ScriptDocValues} instance can be reused to return
  * values form multiple documents.
  */
-public abstract class ScriptDocValues<T> extends AbstractList<T> {
+public abstract class ScriptDocValues<T> extends AbstractList<T> implements FieldValues<T> {
 
     /**
      * Set the current doc ID.
@@ -68,6 +73,31 @@ public final void sort(Comparator<? super T> c) {
         throw new UnsupportedOperationException("doc values are unmodifiable");
     }
 
+    public abstract Field<T> toField(String fieldName);
+
+    public List<T> getValues() {
+        return this;
+    }
+
+    public T getNonPrimitiveValue() {
+        return get(0);
+    }
+
+    public long getLongValue() {
+        throw new InvalidConversion(this.getClass(), long.class);
+    }
+
+    public double getDoubleValue() {
+        throw new InvalidConversion(this.getClass(), double.class);
+    }
+
+    protected void throwIfEmpty() {
+        if (size() == 0) {
+            throw new IllegalStateException("A document doesn't have a value for a field! " +
+                "Use doc[<field>].size()==0 to check if a document is missing a field!");
+        }
+    }
+
     public static final class Longs extends ScriptDocValues<Long> {
         private final SortedNumericDocValues in;
         private long[] values = new long[0];
@@ -107,17 +137,31 @@ public long getValue() {
 
         @Override
         public Long get(int index) {
-            if (count == 0) {
-                throw new IllegalStateException("A document doesn't have a value for a field! " +
-                    "Use doc[<field>].size()==0 to check if a document is missing a field!");
-            }
+            throwIfEmpty();
             return values[index];
         }
 
         @Override
         public int size() {
             return count;
         }
+
+        @Override
+        public long getLongValue() {
+            throwIfEmpty();
+            return values[0];
+        }
+
+        @Override
+        public double getDoubleValue() {
+            throwIfEmpty();
+            return values[0];
+        }
+
+        @Override
+        public Field<Long> toField(String fieldName) {
+            return new Field.LongField(fieldName, this);
+        }
     }
 
     public static final class Dates extends ScriptDocValues<JodaCompatibleZonedDateTime> {
@@ -192,6 +236,29 @@ void refreshArray() throws IOException {
                 }
             }
         }
+
+        @Override
+        public long getLongValue() {
+            throwIfEmpty();
+            Instant dt = dates[0].toInstant();
+            if (isNanos) {
+                return TimeUnit.SECONDS.toNanos(dt.getEpochSecond()) + dt.getNano();
+            }
+            return dt.toEpochMilli();
+        }
+
+        @Override
+        public double getDoubleValue() {
+            return getLongValue();
+        }
+
+        @Override
+        public Field<JodaCompatibleZonedDateTime> toField(String fieldName) {
+            if (isNanos) {
+                return new Field.DateNanosField(fieldName, this);
+            }
+            return new Field.DateMillisField(fieldName, this);
+        }
     }
 
     public static final class Doubles extends ScriptDocValues<Double> {
@@ -246,6 +313,22 @@ public Double get(int index) {
         public int size() {
             return count;
         }
+
+        @Override
+        public long getLongValue() {
+            return (long) getDoubleValue();
+        }
+
+        @Override
+        public double getDoubleValue() {
+            throwIfEmpty();
+            return values[0];
+        }
+
+        @Override
+        public Field<Double> toField(String fieldName) {
+            return new Field.DoubleField(fieldName, this);
+        }
     }
 
     public abstract static class Geometry<T> extends ScriptDocValues<T> {
@@ -436,6 +519,11 @@ public double getMercatorHeight() {
         public GeoBoundingBox getBoundingBox() {
           return size() == 0 ? null : boundingBox;
         }
+
+        @Override
+        public Field<GeoPoint> toField(String fieldName) {
+            return new Field.GeoPointField(fieldName, this);
+        }
     }
 
     public static final class Booleans extends ScriptDocValues<Boolean> {
@@ -496,6 +584,22 @@ private static boolean[] grow(boolean[] array, int minSize) {
                 return array;
         }
 
+        @Override
+        public long getLongValue() {
+            throwIfEmpty();
+            return values[0] ? 1L : 0L;
+        }
+
+        @Override
+        public double getDoubleValue() {
+            throwIfEmpty();
+            return values[0] ? 1.0D : 0.0D;
+        }
+
+        @Override
+        public Field<Boolean> toField(String fieldName) {
+            return new Field.BooleanField(fieldName, this);
+        }
     }
 
     abstract static class BinaryScriptDocValues<T> extends ScriptDocValues<T> {
@@ -568,6 +672,21 @@ protected String bytesToString(BytesRef bytes) {
         public final String getValue() {
             return get(0);
         }
+
+        @Override
+        public long getLongValue() {
+            return Long.parseLong(get(0));
+        }
+
+        @Override
+        public double getDoubleValue() {
+            return Double.parseDouble(get(0));
+        }
+
+        @Override
+        public Field<String> toField(String fieldName) {
+            return new Field.StringField(fieldName, this);
+        }
     }
 
     public static final class BytesRefs extends BinaryScriptDocValues<BytesRef> {
@@ -594,5 +713,9 @@ public BytesRef getValue() {
             return get(0);
         }
 
+        @Override
+        public Field<BytesRef> toField(String fieldName) {
+            return new Field.BytesRefField(fieldName, this);
+        }
     }
 }

server/src/main/java/org/elasticsearch/index/mapper/IpFieldMapper.java

@@ -355,6 +355,11 @@ public String get(int index) {
             public int size() {
                 return count;
             }
+
+            @Override
+            public org.elasticsearch.script.Field<String> toField(String fieldName) {
+                return new org.elasticsearch.script.Field.IpField(fieldName, this);
+            }
         }
 
         @Override

server/src/main/java/org/elasticsearch/script/Converter.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.script;
+
+/**
+ * Converts between one scripting {@link Field} type and another,  {@code CF}, with a different underlying
+ * value type, {@code CT}.
+ */
+public interface Converter<CT, CF extends Field<CT>> {
+    /**
+     * Convert {@code sourceField} to a new field-type.  Conversions come from user scripts so {@code covert} may
+     * be called on a {@link Field}'s own type.
+     */
+    CF convert(Field<?> sourceField);
+
+    /**
+     * The destination {@link Field} class.
+     */
+    Class<CF> getFieldClass();
+
+    /**
+     * The target value type.
+     */
+    Class<CT> getTargetClass();
+}