| /* |
| * 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 org.apache.solr.client.solrj.io.Tuple; |
| import org.apache.solr.client.solrj.io.comp.StreamComparator; |
| import org.apache.solr.client.solrj.io.eq.FieldEqualitor; |
| import org.apache.solr.client.solrj.io.eq.StreamEqualitor; |
| 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.StreamExpressionNamedParameter; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionValue; |
| import org.apache.solr.client.solrj.io.stream.expr.StreamFactory; |
| |
| /** |
| * Emits tuples from streamA which do not exist in streamB. Resulting tuples are ordered |
| * the same as they were in streamA. Both streams must be sorted by the fields being compared. |
| * @since 6.0.0 |
| **/ |
| |
| public class ComplementStream extends TupleStream implements Expressible { |
| |
| private static final long serialVersionUID = 1; |
| |
| private PushBackStream streamA; |
| private PushBackStream streamB; |
| private TupleStream originalStreamB; |
| private StreamEqualitor eq; |
| |
| public ComplementStream(TupleStream streamA, TupleStream streamB, StreamEqualitor eq) throws IOException { |
| init(streamA, streamB, eq); |
| } |
| |
| public ComplementStream(StreamExpression expression,StreamFactory factory) throws IOException { |
| // grab all parameters out |
| List<StreamExpression> streamExpressions = factory.getExpressionOperandsRepresentingTypes(expression, Expressible.class, TupleStream.class); |
| StreamExpressionNamedParameter onExpression = factory.getNamedOperand(expression, "on"); |
| |
| // validate expression contains only what we want. |
| if(expression.getParameters().size() != streamExpressions.size() + 1){ |
| throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - unknown operands found", expression)); |
| } |
| |
| if(2 != streamExpressions.size()){ |
| throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting two streams but found %d (must be TupleStream types)",expression, streamExpressions.size())); |
| } |
| |
| if(null == onExpression || !(onExpression.getParameter() instanceof StreamExpressionValue)){ |
| throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - expecting single 'on' parameter listing fields to merge on but didn't find one",expression)); |
| } |
| |
| init( factory.constructStream(streamExpressions.get(0)), |
| factory.constructStream(streamExpressions.get(1)), |
| factory.constructEqualitor(((StreamExpressionValue)onExpression.getParameter()).getValue(), FieldEqualitor.class) |
| ); |
| } |
| |
| private void init(TupleStream streamA, TupleStream streamB, StreamEqualitor eq) throws IOException { |
| this.streamA = new PushBackStream(streamA); |
| this.streamB = new PushBackStream(new UniqueStream(streamB, eq)); |
| this.originalStreamB = streamB; // hold onto this for toExpression |
| this.eq = eq; |
| |
| // streamA and streamB must both be sorted so that comp can be derived from |
| if(!eq.isDerivedFrom(streamA.getStreamSort()) || !eq.isDerivedFrom(streamB.getStreamSort())){ |
| throw new IOException("Invalid ComplementStream - both substream comparators (sort) must be a superset of this stream's equalitor."); |
| } |
| } |
| |
| @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())); |
| |
| if(includeStreams){ |
| // streams |
| if(streamA instanceof Expressible){ |
| expression.addParameter(((Expressible)streamA).toExpression(factory)); |
| } |
| else{ |
| throw new IOException("This IntersectionStream contains a non-expressible TupleStream - it cannot be converted to an expression"); |
| } |
| |
| if(originalStreamB instanceof Expressible){ |
| expression.addParameter(((Expressible)originalStreamB).toExpression(factory)); |
| } |
| else{ |
| throw new IOException("This IntersectStream contains a non-expressible TupleStream - it cannot be converted to an expression"); |
| } |
| } |
| else{ |
| expression.addParameter("<stream>"); |
| expression.addParameter("<stream>"); |
| } |
| |
| // on |
| expression.addParameter(new StreamExpressionNamedParameter("on",eq.toExpression(factory))); |
| |
| return expression; |
| } |
| |
| @Override |
| public Explanation toExplanation(StreamFactory factory) throws IOException { |
| |
| return new StreamExplanation(getStreamNodeId().toString()) |
| .withChildren(new Explanation[]{ |
| streamA.toExplanation(factory), |
| originalStreamB.toExplanation(factory) |
| }) |
| .withFunctionName(factory.getFunctionName(this.getClass())) |
| .withImplementingClass(this.getClass().getName()) |
| .withExpressionType(ExpressionType.STREAM_DECORATOR) |
| .withExpression(toExpression(factory, false).toString()) |
| .withHelper(eq.toExplanation(factory)) |
| ; |
| } |
| |
| public void setStreamContext(StreamContext context) { |
| this.streamA.setStreamContext(context); |
| this.streamB.setStreamContext(context); |
| } |
| |
| public List<TupleStream> children() { |
| List<TupleStream> l = new ArrayList<TupleStream>(); |
| l.add(streamA); |
| l.add(streamB); |
| return l; |
| } |
| |
| public void open() throws IOException { |
| streamA.open(); |
| streamB.open(); |
| } |
| |
| public void close() throws IOException { |
| streamA.close(); |
| streamB.close(); |
| } |
| |
| public Tuple read() throws IOException { |
| |
| while(true){ |
| Tuple a = streamA.read(); |
| Tuple b = streamB.read(); |
| |
| // if a is EOF then we're done |
| if(a.EOF){ return a; } |
| |
| // if b is EOF then return a |
| if(b.EOF){ |
| streamB.pushBack(b); |
| return a; |
| } |
| |
| // if a != b && a < b then we know there is no b which a might equal so return a |
| if(!eq.test(a, b) && streamA.getStreamSort().compare(a, b) < 0){ |
| streamB.pushBack(b); |
| return a; |
| } |
| |
| // if a == b then ignore a cause it exists in b |
| // else we know that b < a so we can ignore b |
| if(eq.test(a, b)){ |
| streamB.pushBack(b); |
| } |
| else{ |
| streamA.pushBack(a); |
| } |
| } |
| } |
| |
| /** Return the stream sort - ie, the order in which records are returned */ |
| public StreamComparator getStreamSort(){ |
| return streamA.getStreamSort(); |
| } |
| |
| |
| public int getCost() { |
| return 0; |
| } |
| } |