--- /dev/null
+package org.apache.lucene.search.function;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.search.FieldCache;
+import org.apache.lucene.search.function.DocValues;
+
+import java.io.IOException;
+
+/**
+ * Expert: obtains short field values from the
+ * {@link org.apache.lucene.search.FieldCache FieldCache}
+ * using <code>getShorts()</code> and makes those values
+ * available as other numeric types, casting as needed.
+ *
+ * @lucene.experimental
+ *
+ * @see org.apache.lucene.search.function.FieldCacheSource for requirements
+ * on the field.
+ *
+ * <p><b>NOTE</b>: with the switch in 2.9 to segment-based
+ * searching, if {@link #getValues} is invoked with a
+ * composite (multi-segment) reader, this can easily cause
+ * double RAM usage for the values in the FieldCache. It's
+ * best to switch your application to pass only atomic
+ * (single segment) readers to this API.</p>
+ */
+public class ShortFieldSource extends FieldCacheSource {
+ private FieldCache.ShortParser parser;
+
+ /**
+ * Create a cached short field source with default string-to-short parser.
+ */
+ public ShortFieldSource(String field) {
+ this(field, null);
+ }
+
+ /**
+ * Create a cached short field source with a specific string-to-short parser.
+ */
+ public ShortFieldSource(String field, FieldCache.ShortParser parser) {
+ super(field);
+ this.parser = parser;
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.function.ValueSource#description() */
+ @Override
+ public String description() {
+ return "short(" + super.description() + ')';
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.function.FieldCacheSource#getCachedValues(org.apache.lucene.search.FieldCache, java.lang.String, org.apache.lucene.index.IndexReader) */
+ @Override
+ public DocValues getCachedFieldValues (FieldCache cache, String field, IndexReader reader) throws IOException {
+ final short[] arr = cache.getShorts(reader, field, parser);
+ return new DocValues() {
+ /*(non-Javadoc) @see org.apache.lucene.search.function.DocValues#floatVal(int) */
+ @Override
+ public float floatVal(int doc) {
+ return arr[doc];
+ }
+ /*(non-Javadoc) @see org.apache.lucene.search.function.DocValues#intVal(int) */
+ @Override
+ public int intVal(int doc) {
+ return arr[doc];
+ }
+ /*(non-Javadoc) @see org.apache.lucene.search.function.DocValues#toString(int) */
+ @Override
+ public String toString(int doc) {
+ return description() + '=' + intVal(doc);
+ }
+ /*(non-Javadoc) @see org.apache.lucene.search.function.DocValues#getInnerArray() */
+ @Override
+ Object getInnerArray() {
+ return arr;
+ }
+ };
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.function.FieldCacheSource#cachedFieldSourceEquals(org.apache.lucene.search.function.FieldCacheSource) */
+ @Override
+ public boolean cachedFieldSourceEquals(FieldCacheSource o) {
+ if (o.getClass() != ShortFieldSource.class) {
+ return false;
+ }
+ ShortFieldSource other = (ShortFieldSource)o;
+ return this.parser==null ?
+ other.parser==null :
+ this.parser.getClass() == other.parser.getClass();
+ }
+
+ /*(non-Javadoc) @see org.apache.lucene.search.function.FieldCacheSource#cachedFieldSourceHashCode() */
+ @Override
+ public int cachedFieldSourceHashCode() {
+ return parser==null ?
+ Short.class.hashCode() : parser.getClass().hashCode();
+ }
+
+}