solr/solrj/src/java/org/apache/solr/client/solrj/impl/StreamingBinaryResponseParser.java

/*
 * 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.impl;

import org.apache.solr.client.solrj.StreamingResponseCallback;
import org.apache.solr.common.SolrDocument;
import org.apache.solr.common.SolrDocumentList;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.util.FastInputStream;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.JavaBinCodec;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

/**
 * A BinaryResponseParser that sends callback events rather then build
 * a large response 
 * 
 *
 * @since solr 4.0
 */
public class StreamingBinaryResponseParser extends BinaryResponseParser {
  final StreamingResponseCallback callback;
  
  public StreamingBinaryResponseParser( StreamingResponseCallback cb )
  {
    this.callback = cb;
  }
  
  @Override
  public NamedList<Object> processResponse(InputStream body, String encoding) {
    try {
      JavaBinCodec codec = new JavaBinCodec() {

        @Override
        public SolrDocument readSolrDocument(FastInputStream dis) throws IOException {
          SolrDocument doc = super.readSolrDocument(dis);
          callback.streamSolrDocument( doc );
          return null;
        }

        @Override
        public SolrDocumentList readSolrDocumentList(FastInputStream dis) throws IOException {
          SolrDocumentList solrDocs = new SolrDocumentList();
          List list = (List) readVal(dis);
          solrDocs.setNumFound((Long) list.get(0));
          solrDocs.setStart((Long) list.get(1));
          solrDocs.setMaxScore((Float) list.get(2));

          callback.streamDocListInfo( 
              solrDocs.getNumFound(), 
              solrDocs.getStart(), 
              solrDocs.getMaxScore() );
          
          // Read the Array
          tagByte = dis.readByte();
          if( (tagByte >>> 5) != (ARR >>> 5) ) {
            throw new RuntimeException( "doclist must have an array" );
          } 
          int sz = readSize(dis);
          for (int i = 0; i < sz; i++) {
            // must be a SolrDocument
            readVal( dis ); 
          }
          return solrDocs;
        }
      };
      
      return (NamedList<Object>) codec.unmarshal(body);
    } 
    catch (IOException e) {
      throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "parsing error", e);
    }
  }
}