SOLR-10684: Add finddelay Stream Evaluator

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

@@ -185,6 +185,7 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
       .withFunctionName("percentile", PercentileEvaluator.class)
       .withFunctionName("empiricalDistribution", EmpiricalDistributionEvaluator.class)
       .withFunctionName("describe", DescribeEvaluator.class)
+      .withFunctionName("finddelay", FindDelayEvaluator.class)
 
       // metrics
          .withFunctionName("min", MinMetric.class)

solr/solrj/src/java/org/apache/solr/client/solrj/io/Tuple.java

@@ -90,7 +90,9 @@ public class Tuple implements Cloneable, MapWriter {
     }
 
     if(o instanceof Long) {
-      return (Long)o;
+      return (Long) o;
+    } else if (o instanceof Number) {
+      return ((Number)o).longValue();
     } else {
       //Attempt to parse the long
       return Long.parseLong(o.toString());

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

@@ -0,0 +1,92 @@
+/*
+ * 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.List;
+
+import org.apache.commons.math3.util.MathArrays;
+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 FindDelayEvaluator extends ComplexEvaluator implements Expressible {
+
+  private static final long serialVersionUID = 1;
+
+  public FindDelayEvaluator(StreamExpression expression, StreamFactory factory) throws IOException {
+    super(expression, factory);
+  }
+
+  public Number evaluate(Tuple tuple) throws IOException {
+    StreamEvaluator colEval1 = subEvaluators.get(0);
+    StreamEvaluator colEval2 = subEvaluators.get(1);
+
+    List<Number> numbers1 = (List<Number>)colEval1.evaluate(tuple);
+    List<Number> numbers2 = (List<Number>)colEval2.evaluate(tuple);
+    double[] column1 = new double[numbers1.size()];
+    double[] column2 = new double[numbers2.size()];
+
+    for(int i=0; i<numbers1.size(); i++) {
+      column1[i] = numbers1.get(i).doubleValue();
+    }
+
+    //Reverse the second column.
+    //The convolve function will reverse it back.
+    //This allows correlation to be represented using the convolution math.
+    int rIndex=0;
+    for(int i=numbers2.size()-1; i>=0; i--) {
+      column2[rIndex++] = numbers2.get(i).doubleValue();
+    }
+
+    double[] convolution = MathArrays.convolve(column1, column2);
+    double max = -Double.MAX_VALUE;
+    double maxIndex = -1;
+
+    for(int i=0; i< convolution.length; i++) {
+      double abs = Math.abs(convolution[i]);
+      if(abs > max) {
+        max = abs;
+        maxIndex = i;
+      }
+    }
+
+    return (maxIndex+1)-column2.length;
+  }
+
+  @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

@@ -5864,6 +5864,100 @@ public class StreamExpressionTest extends SolrCloudTestCase {
     assertTrue(prediction == 600.0D);
   }
 
+
+  @Test
+  public void testFinddelay() throws Exception {
+    UpdateRequest updateRequest = new UpdateRequest();
+
+    //Pad column 1 with three zeros.
+    updateRequest.add(id, "10", "price_f", "0.0", "col_s", "a", "order_i", "0");
+    updateRequest.add(id, "11", "price_f", "0.0", "col_s", "a", "order_i", "0");
+    updateRequest.add(id, "12", "price_f", "0.0", "col_s", "a", "order_i", "0");
+    updateRequest.add(id, "1", "price_f", "100.0", "col_s", "a", "order_i", "1");
+    updateRequest.add(id, "2", "price_f", "200.0", "col_s", "a", "order_i", "2");
+    updateRequest.add(id, "3", "price_f", "300.0", "col_s", "a", "order_i", "3");
+    updateRequest.add(id, "4", "price_f", "100.0", "col_s", "a", "order_i", "4");
+    updateRequest.add(id, "5", "price_f", "200.0", "col_s", "a", "order_i", "5");
+    updateRequest.add(id, "6", "price_f", "400.0", "col_s", "a", "order_i", "6");
+    updateRequest.add(id, "7", "price_f", "600.0", "col_s", "a", "order_i", "7");
+
+    updateRequest.add(id, "100", "price_f", "200.0", "col_s", "b", "order_i", "1");
+    updateRequest.add(id, "101", "price_f", "400.0", "col_s", "b", "order_i", "2");
+    updateRequest.add(id, "102", "price_f", "600.0", "col_s", "b", "order_i", "3");
+    updateRequest.add(id, "103", "price_f", "200.0", "col_s", "b", "order_i", "4");
+    updateRequest.add(id, "104", "price_f", "400.0", "col_s", "b", "order_i", "5");
+    updateRequest.add(id, "105", "price_f", "800.0", "col_s", "b", "order_i", "6");
+    updateRequest.add(id, "106", "price_f", "1200.0", "col_s", "b", "order_i", "7");
+
+
+    updateRequest.add(id, "200", "price_f", "-200.0", "col_s", "c", "order_i", "1");
+    updateRequest.add(id, "301", "price_f", "-400.0", "col_s", "c", "order_i", "2");
+    updateRequest.add(id, "402", "price_f", "-600.0", "col_s", "c", "order_i", "3");
+    updateRequest.add(id, "503", "price_f", "-200.0", "col_s", "c", "order_i", "4");
+    updateRequest.add(id, "604", "price_f", "-400.0", "col_s", "c", "order_i", "5");
+    updateRequest.add(id, "705", "price_f", "-800.0", "col_s", "c", "order_i", "6");
+    updateRequest.add(id, "806", "price_f", "-1200.0", "col_s", "c", "order_i", "7");
+    updateRequest.commit(cluster.getSolrClient(), COLLECTIONORALIAS);
+
+    String expr1 = "search("+COLLECTIONORALIAS+", q=\"col_s:a\", fl=\"price_f, order_i\", sort=\"order_i asc\")";
+    String expr2 = "search("+COLLECTIONORALIAS+", q=\"col_s:b\", fl=\"price_f, order_i\", sort=\"order_i asc\")";
+
+    String cexpr = "let(a="+expr1+", b="+expr2+", c=col(a, price_f), d=col(b, price_f), tuple(delay=finddelay(c, d)))";
+
+    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);
+    Tuple tuple = tuples.get(0);
+    long delay = tuple.getLong("delay");
+    assert(delay == 3);
+
+    expr1 = "search("+COLLECTIONORALIAS+", q=\"col_s:a\", fq=\"id:(1 2 3 4 5 6 7)\", fl=\"price_f, order_i\", sort=\"order_i asc\")";
+    expr2 = "search("+COLLECTIONORALIAS+", q=\"col_s:b\", fl=\"price_f, order_i\", sort=\"order_i asc\")";
+
+    cexpr = "let(a="+expr1+", b="+expr2+", c=col(a, price_f), d=col(b, price_f), tuple(delay=finddelay(c, d)))";
+
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    tuple = tuples.get(0);
+    delay = tuple.getLong("delay");
+    assert(delay == 0);
+
+    //Test negative correlation.
+    expr1 = "search("+COLLECTIONORALIAS+", q=\"col_s:a\", fq=\"id:(1 2 3 4 5 6 7 11 12)\",fl=\"price_f, order_i\", sort=\"order_i asc\")";
+    expr2 = "search("+COLLECTIONORALIAS+", q=\"col_s:c\", fl=\"price_f, order_i\", sort=\"order_i asc\")";
+
+    cexpr = "let(a="+expr1+", b="+expr2+", c=col(a, price_f), d=col(b, price_f), tuple(delay=finddelay(c, d)))";
+
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cexpr);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 1);
+    tuple = tuples.get(0);
+    delay = tuple.getLong("delay");
+    assert(delay == 2);
+  }
+
+
   @Test
   public void testDescribe() throws Exception {
     UpdateRequest updateRequest = new UpdateRequest();