SOLR-10559: Add let and get Streaming Expressions

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

@@ -163,7 +163,8 @@ public class StreamHandler extends RequestHandlerBase implements SolrCoreAware,
       .withFunctionName("echo", EchoStream.class)
       .withFunctionName("cell", CellStream.class)
       .withFunctionName("list", ListStream.class)
-
+      .withFunctionName("let", LetStream.class)
+      .withFunctionName("get", GetStream.class)
       // metrics
          .withFunctionName("min", MinMetric.class)
       .withFunctionName("max", MaxMetric.class)

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

@@ -56,6 +56,10 @@ public class CellStream extends TupleStream implements Expressible {
     init(name, tupleStream);
   }
 
+  public String getName() {
+    return this.name;
+  }
+
   private void init(String name, TupleStream tupleStream) {
     this.name = name;
     this.stream = tupleStream;

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

@@ -0,0 +1,117 @@
+/*
+ * 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.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.comp.StreamComparator;
+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.StreamExplanation;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class GetStream extends TupleStream implements Expressible {
+
+  private static final long serialVersionUID = 1;
+
+  private StreamContext streamContext;
+  private String name;
+  private Iterator<Tuple> tupleIterator;
+
+  public GetStream(String name) throws IOException {
+    init(name);
+  }
+
+  public GetStream(StreamExpression expression, StreamFactory factory) throws IOException {
+    String name = factory.getValueOperand(expression, 0);
+    init(name);
+  }
+
+  private void init(String name) {
+    this.name = name;
+  }
+
+  @Override
+  public StreamExpression toExpression(StreamFactory factory) throws IOException{
+    return toExpression(factory, true);
+  }
+
+  private StreamExpression toExpression(StreamFactory factory, boolean includeStreams) throws IOException {
+    // function name
+    StreamExpression expression = new StreamExpression(factory.getFunctionName(this.getClass()));
+    expression.addParameter(name);
+    return expression;
+  }
+
+  @Override
+  public Explanation toExplanation(StreamFactory factory) throws IOException {
+
+    StreamExplanation explanation = new StreamExplanation(getStreamNodeId().toString());
+    explanation.setFunctionName(factory.getFunctionName(this.getClass()));
+    explanation.setImplementingClass(this.getClass().getName());
+    explanation.setExpressionType(ExpressionType.STREAM_SOURCE);
+    explanation.setExpression(toExpression(factory, false).toString());
+    return explanation;
+  }
+
+  public void setStreamContext(StreamContext context) {
+    this.streamContext = context;
+  }
+
+  public List<TupleStream> children() {
+    List<TupleStream> l =  new ArrayList();
+    return l;
+  }
+
+  public Tuple read() throws IOException {
+    Map map = new HashMap();
+    if(tupleIterator.hasNext()) {
+      Tuple t = tupleIterator.next();
+      map.putAll(t.fields);
+      return new Tuple(map);
+    } else {
+      map.put("EOF", true);
+      return new Tuple(map);
+    }
+  }
+
+  public void close() throws IOException {
+  }
+
+  public void open() throws IOException {
+    Map<String, List<Tuple>> lets = streamContext.getLets();
+    List<Tuple> tuples = lets.get(name);
+    tupleIterator = tuples.iterator();
+  }
+
+  /** Return the stream sort - ie, the order in which records are returned */
+  public StreamComparator getStreamSort(){
+    return null;
+  }
+
+  public int getCost() {
+    return 0;
+  }
+}

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

@@ -0,0 +1,152 @@
+/*
+ * 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.List;
+import java.util.Locale;
+import java.util.Map;
+
+import org.apache.solr.client.solrj.io.Tuple;
+import org.apache.solr.client.solrj.io.comp.StreamComparator;
+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.StreamExplanation;
+import org.apache.solr.client.solrj.io.stream.expr.StreamExpression;
+import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
+
+public class LetStream extends TupleStream implements Expressible {
+
+  private static final long serialVersionUID = 1;
+  private TupleStream stream;
+  private List<CellStream> cellStreams;
+  private StreamContext streamContext;
+
+  public LetStream(TupleStream stream, List<CellStream> cellStreams) throws IOException {
+    init(stream, cellStreams);
+  }
+
+  public LetStream(StreamExpression expression, StreamFactory factory) throws IOException {
+    List<StreamExpression> streamExpressions = factory.getExpressionOperandsRepresentingTypes(expression, Expressible.class, TupleStream.class);
+
+    if(streamExpressions.size() < 2){
+      throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting atleast 2 streams but found %d",expression, streamExpressions.size()));
+    }
+
+    TupleStream stream = null;
+    List<CellStream> cellStreams = new ArrayList();
+
+    for(StreamExpression streamExpression : streamExpressions) {
+      TupleStream s = factory.constructStream(streamExpression);
+      if(s instanceof CellStream) {
+        cellStreams.add((CellStream)s);
+      } else {
+        if(stream == null) {
+          stream = s;
+        } else {
+          throw new IOException("Found more then one stream that was not a CellStream");
+        }
+      }
+    }
+
+    init(stream, cellStreams);
+  }
+
+  private void init(TupleStream _stream, List<CellStream> _cellStreams) {
+    this.stream = _stream;
+    this.cellStreams = _cellStreams;
+  }
+
+  @Override
+  public StreamExpression toExpression(StreamFactory factory) throws IOException{
+    return toExpression(factory, true);
+  }
+
+  private StreamExpression toExpression(StreamFactory factory, boolean includeStreams) throws IOException {
+    // function name
+    StreamExpression expression = new StreamExpression(factory.getFunctionName(this.getClass()));
+    expression.addParameter(((Expressible) stream).toExpression(factory));
+    for(CellStream cellStream : cellStreams) {
+      expression.addParameter(((Expressible)cellStream).toExpression(factory));
+    }
+
+    return expression;
+  }
+
+  @Override
+  public Explanation toExplanation(StreamFactory factory) throws IOException {
+
+    StreamExplanation explanation = new StreamExplanation(getStreamNodeId().toString());
+    explanation.setFunctionName(factory.getFunctionName(this.getClass()));
+    explanation.setImplementingClass(this.getClass().getName());
+    explanation.setExpressionType(ExpressionType.STREAM_DECORATOR);
+    explanation.setExpression(toExpression(factory, false).toString());
+    explanation.addChild(stream.toExplanation(factory));
+
+    return explanation;
+  }
+
+  public void setStreamContext(StreamContext context) {
+    this.streamContext = context;
+    this.stream.setStreamContext(context);
+  }
+
+  public List<TupleStream> children() {
+    List<TupleStream> l =  new ArrayList<TupleStream>();
+    l.add(stream);
+
+    return l;
+  }
+
+  public Tuple read() throws IOException {
+    return stream.read();
+  }
+
+  public void close() throws IOException {
+    stream.close();
+  }
+
+  public void open() throws IOException {
+    Map<String, List<Tuple>> lets = streamContext.getLets();
+    for(CellStream cellStream : cellStreams) {
+      try {
+        cellStream.setStreamContext(streamContext);
+        cellStream.open();
+        Tuple tup = cellStream.read();
+        String name = cellStream.getName();
+        List<Tuple> tuples = (List<Tuple>)tup.get(name);
+        lets.put(name, tuples);
+      } finally {
+        cellStream.close();
+      }
+    }
+    stream.open();
+  }
+
+  /** Return the stream sort - ie, the order in which records are returned */
+  public StreamComparator getStreamSort(){
+    return null;
+  }
+
+  public int getCost() {
+    return 0;
+  }
+
+
+}

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

@@ -19,8 +19,10 @@ package org.apache.solr.client.solrj.io.stream;
 import java.io.Serializable;
 import java.util.Map;
 import java.util.HashMap;
+import java.util.List;
 
 import org.apache.solr.client.solrj.io.ModelCache;
+import org.apache.solr.client.solrj.io.Tuple;
 import org.apache.solr.client.solrj.io.SolrClientCache;
 import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
 
@@ -37,12 +39,17 @@ public class StreamContext implements Serializable{
 
   private Map entries = new HashMap();
   private Map tupleContext = new HashMap();
+  private Map<String, List<Tuple>> lets = new HashMap();
   public int workerID;
   public int numWorkers;
   private SolrClientCache clientCache;
   private ModelCache modelCache;
   private StreamFactory streamFactory;
 
+  public Map<String, List<Tuple>> getLets(){
+    return lets;
+  }
+
   public Object get(Object key) {
     return entries.get(key);
   }

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

@@ -5099,6 +5099,82 @@ public class StreamExpressionTest extends SolrCloudTestCase {
 
   }
 
+  @Test
+  public void testLetGetStream() throws Exception {
+    UpdateRequest updateRequest = new UpdateRequest();
+    updateRequest.add(id, "hello", "test_t", "l b c d c e");
+    updateRequest.add(id, "hello1", "test_t", "l b c d c");
+
+    updateRequest.commit(cluster.getSolrClient(), COLLECTIONORALIAS);
+
+    String expr = "search("+COLLECTIONORALIAS+", q=\"*:*\", fl=\"id,test_t\", sort=\"id desc\")";
+    String cat = "let(cell(results,"+expr+"), get(results))";
+    ModifiableSolrParams paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cat);
+    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() == 2);
+    assertTrue(tuples.get(0).get("id").equals("hello1"));
+    assertTrue(tuples.get(0).get("test_t").equals("l b c d c"));
+    assertTrue(tuples.get(1).get("id").equals("hello"));
+    assertTrue(tuples.get(1).get("test_t").equals("l b c d c e"));
+
+
+    //Test there are no side effects when transforming tuples.
+    expr = "search("+COLLECTIONORALIAS+", q=\"*:*\", fl=\"id,test_t\", sort=\"id desc\")";
+    cat = "let(cell(results,"+expr+"), list(select(get(results), id as newid, test_t), get(results)))";
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cat);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    context = new StreamContext();
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 4);
+    assertTrue(tuples.get(0).get("newid").equals("hello1"));
+    assertTrue(tuples.get(0).get("test_t").equals("l b c d c"));
+    assertTrue(tuples.get(1).get("newid").equals("hello"));
+    assertTrue(tuples.get(1).get("test_t").equals("l b c d c e"));
+    assertTrue(tuples.get(2).get("id").equals("hello1"));
+    assertTrue(tuples.get(2).get("test_t").equals("l b c d c"));
+    assertTrue(tuples.get(3).get("id").equals("hello"));
+    assertTrue(tuples.get(3).get("test_t").equals("l b c d c e"));
+
+    //Test multiple lets
+
+    //Test there are no side effects when transforming tuples.
+    expr = "search("+COLLECTIONORALIAS+", q=\"*:*\", fl=\"id,test_t\", sort=\"id desc\")";
+    String expr1 = "search("+COLLECTIONORALIAS+", q=\"*:*\", fl=\"id,test_t\", sort=\"id asc\")";
+
+    cat = "let(cell(results,"+expr+"), cell(results1,"+expr1+"), list(select(get(results), id as newid, test_t), get(results1)))";
+    paramsLoc = new ModifiableSolrParams();
+    paramsLoc.set("expr", cat);
+    paramsLoc.set("qt", "/stream");
+
+    solrStream = new SolrStream(url, paramsLoc);
+
+    context = new StreamContext();
+    solrStream.setStreamContext(context);
+    tuples = getTuples(solrStream);
+    assertTrue(tuples.size() == 4);
+    assertTrue(tuples.get(0).get("newid").equals("hello1"));
+    assertTrue(tuples.get(0).get("test_t").equals("l b c d c"));
+    assertTrue(tuples.get(1).get("newid").equals("hello"));
+    assertTrue(tuples.get(1).get("test_t").equals("l b c d c e"));
+    assertTrue(tuples.get(2).get("id").equals("hello"));
+    assertTrue(tuples.get(2).get("test_t").equals("l b c d c e"));
+    assertTrue(tuples.get(3).get("id").equals("hello1"));
+    assertTrue(tuples.get(3).get("test_t").equals("l b c d c"));
+  }
+
   @Test
   public void testConvertEvaluator() throws Exception {