Add long flavored script field (#59721)

This adds the `long` runtime type to `script` fields and implements doc
values, field data, the `term` and `exists` query.

Author: nik9000

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

@@ -701,23 +701,7 @@ public List<Field> createFields(String name, Number value,
         LONG("long", NumericType.LONG) {
             @Override
             public Long parse(Object value, boolean coerce) {
-                if (value instanceof Long) {
-                    return (Long)value;
-                }
-
-                double doubleValue = objectToDouble(value);
-                // this check does not guarantee that value is inside MIN_VALUE/MAX_VALUE because values up to 9223372036854776832 will
-                // be equal to Long.MAX_VALUE after conversion to double. More checks ahead.
-                if (doubleValue < Long.MIN_VALUE || doubleValue > Long.MAX_VALUE) {
-                    throw new IllegalArgumentException("Value [" + value + "] is out of range for a long");
-                }
-                if (!coerce && doubleValue % 1 != 0) {
-                    throw new IllegalArgumentException("Value [" + value + "] has a decimal part");
-                }
-
-                // longs need special handling so we don't lose precision while parsing
-                String stringValue = (value instanceof BytesRef) ? ((BytesRef) value).utf8ToString() : value.toString();
-                return Numbers.toLong(stringValue, coerce);
+                return objectToLong(value, coerce);
             }
 
             @Override
@@ -854,7 +838,7 @@ Number valueForSearch(Number value) {
         /**
          * Returns true if the object is a number and has a decimal part
          */
-        boolean hasDecimalPart(Object number) {
+        public static boolean hasDecimalPart(Object number) {
             if (number instanceof Number) {
                 double doubleValue = ((Number) number).doubleValue();
                 return doubleValue % 1 != 0;
@@ -898,6 +882,30 @@ private static double objectToDouble(Object value) {
 
             return doubleValue;
         }
+
+        /**
+         * Converts and Object to a {@code long} by checking it against known
+         * types and checking its range.
+         */
+        public static long objectToLong(Object value, boolean coerce) {
+            if (value instanceof Long) {
+                return (Long)value;
+            }
+
+            double doubleValue = objectToDouble(value);
+            // this check does not guarantee that value is inside MIN_VALUE/MAX_VALUE because values up to 9223372036854776832 will
+            // be equal to Long.MAX_VALUE after conversion to double. More checks ahead.
+            if (doubleValue < Long.MIN_VALUE || doubleValue > Long.MAX_VALUE) {
+                throw new IllegalArgumentException("Value [" + value + "] is out of range for a long");
+            }
+            if (!coerce && doubleValue % 1 != 0) {
+                throw new IllegalArgumentException("Value [" + value + "] has a decimal part");
+            }
+
+            // longs need special handling so we don't lose precision while parsing
+            String stringValue = (value instanceof BytesRef) ? ((BytesRef) value).utf8ToString() : value.toString();
+            return Numbers.toLong(stringValue, coerce);
+        }
     }
 
     public static final class NumberFieldType extends SimpleMappedFieldType {

x-pack/plugin/runtime-fields/src/main/java/org/elasticsearch/xpack/runtimefields/LongScriptFieldScript.java

@@ -7,6 +7,7 @@
 package org.elasticsearch.xpack.runtimefields;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.util.ArrayUtil;
 import org.elasticsearch.painless.spi.Whitelist;
 import org.elasticsearch.painless.spi.WhitelistLoader;
 import org.elasticsearch.script.ScriptContext;
@@ -16,10 +17,9 @@
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
-import java.util.function.LongConsumer;
 
 public abstract class LongScriptFieldScript extends AbstractScriptFieldScript {
-    static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("long_script_field", Factory.class);
+    public static final ScriptContext<Factory> CONTEXT = new ScriptContext<>("long_script_field", Factory.class);
 
     static List<Whitelist> whitelist() {
         return List.of(WhitelistLoader.loadFromResourceFiles(RuntimeFieldsPainlessExtension.class, "long_whitelist.txt"));
@@ -32,14 +32,47 @@ public interface Factory extends ScriptFactory {
     }
 
     public interface LeafFactory {
-        LongScriptFieldScript newInstance(LeafReaderContext ctx, LongConsumer sync) throws IOException;
+        LongScriptFieldScript newInstance(LeafReaderContext ctx) throws IOException;
     }
 
-    private final LongConsumer sync;
+    private long[] values = new long[1];
+    private int count;
 
-    public LongScriptFieldScript(Map<String, Object> params, SearchLookup searchLookup, LeafReaderContext ctx, LongConsumer sync) {
+    public LongScriptFieldScript(Map<String, Object> params, SearchLookup searchLookup, LeafReaderContext ctx) {
         super(params, searchLookup, ctx);
-        this.sync = sync;
+    }
+
+    /**
+     * Execute the script for the provided {@code docId}.
+     */
+    public final void runForDoc(int docId) {
+        count = 0;
+        setDocument(docId);
+        execute();
+    }
+
+    /**
+     * Values from the last time {@link #runForDoc(int)} was called. This array
+     * is mutable and will change with the next call of {@link #runForDoc(int)}.
+     * It is also oversized and will contain garbage at all indices at and
+     * above {@link #count()}.
+     */
+    public final long[] values() {
+        return values;
+    }
+
+    /**
+     * The number of results produced the last time {@link #runForDoc(int)} was called.
+     */
+    public final int count() {
+        return count;
+    }
+
+    private void collectValue(long v) {
+        if (values.length < count + 1) {
+            values = ArrayUtil.grow(values, count + 1);
+        }
+        values[count++] = v;
     }
 
     public static class Value {
@@ -50,7 +83,7 @@ public Value(LongScriptFieldScript script) {
         }
 
         public void value(long v) {
-            script.sync.accept(v);
+            script.collectValue(v);
         }
     }
 }

x-pack/plugin/runtime-fields/src/main/java/org/elasticsearch/xpack/runtimefields/StringScriptFieldScript.java

@@ -35,7 +35,7 @@ public interface LeafFactory {
         StringScriptFieldScript newInstance(LeafReaderContext ctx) throws IOException;
     }
 
-    protected final List<String> results = new ArrayList<>();
+    private final List<String> results = new ArrayList<>();
 
     public StringScriptFieldScript(Map<String, Object> params, SearchLookup searchLookup, LeafReaderContext ctx) {
         super(params, searchLookup, ctx);

x-pack/plugin/runtime-fields/src/main/java/org/elasticsearch/xpack/runtimefields/fielddata/ScriptBinaryFieldData.java

@@ -9,7 +9,7 @@
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.util.SetOnce;
-import org.elasticsearch.ElasticsearchException;
+import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.index.AbstractIndexComponent;
 import org.elasticsearch.index.IndexSettings;
@@ -34,8 +34,6 @@
 import org.elasticsearch.xpack.runtimefields.StringScriptFieldScript;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
 
 public final class ScriptBinaryFieldData extends AbstractIndexComponent
     implements
@@ -81,6 +79,7 @@ private ScriptBinaryFieldData(
         this.scriptFactory = scriptFactory;
     }
 
+    @Override
     public void setSearchLookup(SearchLookup searchLookup) {
         this.leafFactory.set(scriptFactory.newFactory(script.getParams(), searchLookup));
     }
@@ -100,11 +99,7 @@ public ScriptBinaryLeafFieldData load(LeafReaderContext context) {
         try {
             return loadDirect(context);
         } catch (Exception e) {
-            if (e instanceof ElasticsearchException) {
-                throw (ElasticsearchException) e;
-            } else {
-                throw new ElasticsearchException(e);
-            }
+            throw ExceptionsHelper.convertToElastic(e);
         }
     }
 
@@ -165,16 +160,4 @@ public void close() {
 
         }
     }
-
-    static class ScriptBinaryResult {
-        private final List<String> result = new ArrayList<>();
-
-        void accept(String value) {
-            this.result.add(value);
-        }
-
-        List<String> getResult() {
-            return result;
-        }
-    }
 }

x-pack/plugin/runtime-fields/src/main/java/org/elasticsearch/xpack/runtimefields/fielddata/ScriptLongDocValues.java

@@ -0,0 +1,43 @@
+/*
+ * 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.runtimefields.fielddata;
+
+import org.elasticsearch.index.fielddata.AbstractSortedNumericDocValues;
+import org.elasticsearch.xpack.runtimefields.LongScriptFieldScript;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+public final class ScriptLongDocValues extends AbstractSortedNumericDocValues {
+    private final LongScriptFieldScript script;
+    private int cursor;
+
+    ScriptLongDocValues(LongScriptFieldScript script) {
+        this.script = script;
+    }
+
+    @Override
+    public boolean advanceExact(int docId) {
+        script.runForDoc(docId);
+        if (script.count() == 0) {
+            return false;
+        }
+        Arrays.sort(script.values(), 0, script.count());
+        cursor = 0;
+        return true;
+    }
+
+    @Override
+    public long nextValue() throws IOException {
+        return script.values()[cursor++];
+    }
+
+    @Override
+    public int docValueCount() {
+        return script.count();
+    }
+}