/**
* 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.drill.exec.ref.rops;
import java.util.Iterator;
import org.apache.drill.common.logical.data.Constant;
import org.apache.drill.exec.ref.IteratorRegistry;
import org.apache.drill.exec.ref.RecordIterator;
import org.apache.drill.exec.ref.RecordPointer;
import org.apache.drill.exec.ref.RunOutcome.OutcomeType;
import org.apache.drill.exec.ref.UnbackedRecord;
import org.apache.drill.exec.ref.exceptions.SetupException;
import org.apache.drill.exec.ref.rse.JSONRecordReader;
import com.fasterxml.jackson.databind.JsonNode;
public class ConstantROP extends ROPBase<Constant>{
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(ScanROP.class);
private UnbackedRecord record;
public ConstantROP(Constant config) {
super(config);
record = new UnbackedRecord();
}
@Override
protected void setupIterators(IteratorRegistry registry) throws SetupException {
// try{
super.setupIterators(registry);
// need to assign reader
// throw new IOException();
//}catch(IOException e){
//throw new SetupException("Failure while setting up reader.");
//}
}
@Override
protected RecordIterator getIteratorInternal() {
return new ConstantIterator(ConstantROP.this.config.getContent().getRoot());
}
@Override
public void cleanup(OutcomeType outcome) {
super.cleanup(outcome);
}
class ConstantIterator implements RecordIterator {
Iterator<JsonNode> jsonIter;
ConstantIterator(JsonNode json) {
jsonIter = json.elements();
}
public RecordPointer getRecordPointer(){
return record;
}
public NextOutcome next(){
if ( ! jsonIter.hasNext()){
return NextOutcome.NONE_LEFT;
}
JsonNode contentJSON = ConstantROP.this.config.getContent().getRoot();
if (contentJSON.isArray())
{ // list of constant records was specified
JsonNode node;
node = jsonIter.next();
convertJsonToRP(node, record);
return NextOutcome.INCREMENTED_SCHEMA_UNCHANGED;
}
else{
convertJsonToRP(contentJSON, record);
return NextOutcome.NONE_LEFT;
}
}
private void convertJsonToRP(JsonNode node, RecordPointer rp){
record.clear();
record.merge(JSONRecordReader.convert(node));
}
public ROP getParent(){
return ConstantROP.this;
}
}
}