/*
* 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.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.solr.client.solrj.io.Tuple;
import org.apache.solr.client.solrj.io.comp.SingleValueComparator;
import org.apache.solr.client.solrj.io.comp.StreamComparator;
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.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.StreamExpressionParameter;
import org.apache.solr.client.solrj.io.stream.expr.StreamExpressionValue;
import org.apache.solr.client.solrj.io.stream.expr.StreamFactory;
public class TupStream extends TupleStream implements Expressible {
private static final long serialVersionUID = 1;
private StreamContext streamContext;
private Map<String,String> stringParams = new HashMap<>();
private Map<String,StreamEvaluator> evaluatorParams = new HashMap<>();
private Map<String,TupleStream> streamParams = new HashMap<>();
private List<String> fieldNames = new ArrayList();
private Map<String, String> fieldLabels = new HashMap();
private boolean finished;
public TupStream(StreamExpression expression, StreamFactory factory) throws IOException {
List<StreamExpressionNamedParameter> namedParams = factory.getNamedOperands(expression);
//Get all the named params
for(StreamExpressionNamedParameter np : namedParams) {
String name = np.getName();
fieldNames.add(name);
fieldLabels.put(name, name);
StreamExpressionParameter param = np.getParameter();
// we're going to split these up here so we only make the choice once
// order of these in read() doesn't matter
if(param instanceof StreamExpressionValue) {
stringParams.put(name, ((StreamExpressionValue)param).getValue());
} else if (factory.isEvaluator((StreamExpression) param)) {
StreamEvaluator evaluator = factory.constructEvaluator((StreamExpression) param);
evaluatorParams.put(name, evaluator);
} else if(factory.isStream((StreamExpression)param)) {
TupleStream tupleStream = factory.constructStream((StreamExpression) param);
streamParams.put(name, tupleStream);
}
else{
throw new IOException(String.format(Locale.ROOT,"Invalid expression %s - only string, evaluator, or stream named parameters are supported, but param %d is none of those",expression, 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()));
// add string based params
for(Entry<String,String> param : stringParams.entrySet()){
expression.addParameter(new StreamExpressionNamedParameter(param.getKey(), param.getValue()));
}
// add evaluator based params
for(Entry<String,StreamEvaluator> param : evaluatorParams.entrySet()){
expression.addParameter(new StreamExpressionNamedParameter(param.getKey(), param.getValue().toExpression(factory)));
}
// add stream based params
for(Entry<String,TupleStream> param : streamParams.entrySet()){
if(includeStreams){
expression.addParameter(new StreamExpressionNamedParameter(param.getKey(), ((Expressible)param.getValue()).toExpression(factory)));
}
else{
expression.addParameter(new StreamExpressionNamedParameter(param.getKey(), "<stream>"));
}
}
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());
return explanation;
}
public void setStreamContext(StreamContext context) {
this.streamContext = context;
// also set in evalators and streams
for(StreamEvaluator evaluator : evaluatorParams.values()){
evaluator.setStreamContext(context);
}
for(TupleStream stream : streamParams.values()){
stream.setStreamContext(context);
}
}
public List<TupleStream> children() {
List<TupleStream> l = new ArrayList<TupleStream>();
return l;
}
public Tuple read() throws IOException {
if(finished) {
Map<String,Object> m = new HashMap<>();
m.put("EOF", true);
return new Tuple(m);
} else {
finished = true;
Map<String, Object> values = new HashMap<>();
// add all string based params
// these could come from the context, or they will just be treated as straight strings
for(Entry<String,String> param : stringParams.entrySet()){
if(streamContext.getLets().containsKey(param.getValue())){
values.put(param.getKey(), streamContext.getLets().get(param.getValue()));
}
else{
values.put(param.getKey(), param.getValue());
}
}
// add all evaluators
for(Entry<String,StreamEvaluator> param : evaluatorParams.entrySet()){
values.put(param.getKey(), param.getValue().evaluateOverContext());
}
// Add all streams
for(Entry<String,TupleStream> param : streamParams.entrySet()){
try{
List<Tuple> streamTuples = new ArrayList<Tuple>();
// open the stream, closed in finally block
param.getValue().open();
// read all values from stream (memory expensive)
Tuple streamTuple = param.getValue().read();
while(!streamTuple.EOF){
streamTuples.add(streamTuple);
streamTuple = param.getValue().read();
}
values.put(param.getKey(), streamTuples);
}
finally{
// safely close the stream
param.getValue().close();
}
}
Tuple tup = new Tuple(values);
tup.fieldNames = fieldNames;
tup.fieldLabels = fieldLabels;
return tup;
}
}
public void close() throws IOException {
// Nothing to do here
}
public void open() throws IOException {
// nothing to do here
}
/** Return the stream sort - ie, the order in which records are returned */
public StreamComparator getStreamSort(){
return new SingleValueComparator();
}
public int getCost() {
return 0;
}
}