SOLR-10693: Add copyOfRange Stream Evaluator

solr/core/src/java/org/apache/solr/handler/StreamHandler.java

@@ -180,6 +180,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
       .withFunctionName("scale", ScaleEvaluator.class)
       .withFunctionName("distance", DistanceEvaluator.class)
       .withFunctionName("copyOf", CopyOfEvaluator.class)
+      .withFunctionName("copyOfRange", CopyOfRangeEvaluator.class)
       .withFunctionName("percentile", PercentileEvaluator.class)
       .withFunctionName("empiricalDistribution", EmpiricalDistributionEvaluator.class)
 

solr/solrj/src/java/org/apache/solr/client/solrj/io/stream/CopyOfRangeEvaluator.java

@@ -0,0 +1,85 @@
+/*
+ * 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.
+ */
+package org.apache.solr.client.solrj.io.stream;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.apache.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.eval.ComplexEvaluator;
+import org.apache.solr.client.solrj.io.eval.StreamEvaluator;
+import org.apache.solr.client.solrj.io.stream.expr.Explanation;
+import org.apache.solr.client.solrj.io.stream.expr.Explanation.ExpressionType;
+import org.apache.solr.client.solrj.io.stream.expr.Expressible;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionParameter;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class CopyOfRangeEvaluator extends ComplexEvaluator implements Expressible {
+
+  private static final long serialVersionUID = 1;
+
+  public CopyOfRangeEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  public List<Number> evaluate(Tuple tuple) throws IOException {
+    StreamEvaluator colEval1 = subEvaluators.get(0);
+
+    List<Number> numbers1 = (List<Number>)colEval1.evaluate(tuple);
+    double[] vals = new double[numbers1.size()];
+
+    for(int i=0; i<vals.length; i++) {
+      vals[i] = numbers1.get(i).doubleValue();
+    }
+
+    StreamEvaluator startIndexEval = subEvaluators.get(1);
+    Number startIndexNum = (Number)startIndexEval.evaluate(tuple);
+    int startIndex = startIndexNum.intValue();
+
+    StreamEvaluator endIndexEval = subEvaluators.get(2);
+    Number endIndexNum = (Number)endIndexEval.evaluate(tuple);
+    int endIndex = endIndexNum.intValue();
+
+    vals = Arrays.copyOfRange(vals, startIndex, endIndex);
+
+    List<Number> copyOf = new ArrayList(vals.length);
+
+    for(int i=0; i<vals.length; i++) {
+      copyOf.add(vals[i]);
+    }
+
+    return copyOf;
+  }
+
+  @Override
+  public StreamExpressionParameter toExpression(StreamFactory factory) throws IOException {
+    StreamExpression expression = new StreamExpression(factory.getFunctionName(getClass()));
+    return expression;
+  }
+
+  @Override
+  public Explanation toExplanation(StreamFactory factory) throws IOException {
+    return new Explanation(nodeId.toString())
+        .withExpressionType(ExpressionType.EVALUATOR)
+        .withFunctionName(factory.getFunctionName(getClass()))
+        .withImplementingClass(getClass().getName())
+        .withExpression(toExpression(factory).toString());
+  }
+}

solr/solrj/src/test/org/apache/solr/client/solrj/io/stream/StreamExpressionTest.java

@@ -5508,6 +5508,54 @@ public class StreamExpressionTest extends SolrCloudTestCase {
   }
 
 
+  public void testCopyOfRange() throws Exception {
+    UpdateRequest updateRequest = new UpdateRequest();
+
+    int i=0;
+    while(i<50) {
+      updateRequest.add(id, "id_"+(++i),"test_dt", getDateString("2016", "5", "1"), "price_f", "400.00");
+    }
+
+    while(i<100) {
+      updateRequest.add(id, "id_"+(++i),"test_dt", getDateString("2015", "5", "1"), "price_f", "300.0");
+    }
+
+    while(i<150) {
+      updateRequest.add(id, "id_"+(++i),"test_dt", getDateString("2014", "5", "1"), "price_f", "500.0");
+    }
+
+    while(i<250) {
+      updateRequest.add(id, "id_"+(++i),"test_dt", getDateString("2013", "5", "1"), "price_f", "100.00");
+    }
+
+    updateRequest.commit(cluster.getSolrClient(), COLLECTIONORALIAS);
+
+    String expr = "timeseries("+COLLECTIONORALIAS+", q=\"*:*\", start=\"2013-01-01T01:00:00.000Z\", " +
+        "end=\"2016-12-01T01:00:00.000Z\", " +
+        "gap=\"+1YEAR\", " +
+        "field=\"test_dt\", " +
+        "count(*), sum(price_f), max(price_f), min(price_f))";
+
+    String cexpr = "let(a="+expr+", c=col(a, max(price_f)), tuple(copy=copyOfRange(c, 1, 3)))";
+
+    ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    String url = cluster.getJettySolrRunners().get(0).getBaseUrl().toString()+"/"+COLLECTIONORALIAS;
+    TupleStream solrStream = new SolrStream(url, paramsLoc);
+
+    StreamContext context = new StreamContext();
+    solrStream.setStreamContext(context);
+    List<Tuple> tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    List<Number> copy1 = (List<Number>)tuples.get(0).get("copy");
+    assertTrue(copy1.size() == 2);
+    assertTrue(copy1.get(0).doubleValue() == 500D);
+    assertTrue(copy1.get(1).doubleValue() == 300D);
+  }
+
+
   @Test
   public void testPercentiles() throws Exception {
     UpdateRequest updateRequest = new UpdateRequest();