package redstorm.storm.jruby;
import backtype.storm.task.OutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.transactional.TransactionAttempt;
import backtype.storm.topology.base.BaseTransactionalBolt;
import backtype.storm.coordination.BatchOutputCollector;
import backtype.storm.coordination.IBatchBolt;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.tuple.Tuple;
import backtype.storm.tuple.Fields;
import java.util.Map;
import org.jruby.Ruby;
import org.jruby.RubyObject;
import org.jruby.runtime.Helpers;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.javasupport.JavaUtil;
import org.jruby.RubyModule;
import org.jruby.exceptions.RaiseException;
/**
* the JRubyBolt class is a proxy class to the actual bolt implementation in JRuby.
* this proxy is required to bypass the serialization/deserialization issues of JRuby objects.
* JRuby classes do not support Java serialization.
*
* Note that the JRuby bolt class is instanciated in the prepare method which is called after
* deserialization at the worker and in the declareOutputFields & getComponentConfiguration
* methods which are called once before serialization at topology creation.
*/
public class JRubyTransactionalBolt extends BaseTransactionalBolt {
private final String _realBoltClassName;
private final String[] _fields;
private final String _bootstrap;
// transient to avoid serialization
protected transient IRubyObject _ruby_bolt;
protected transient Ruby __ruby__;
/**
* create a new JRubyBolt
*
* @param baseClassPath the topology/project base JRuby class file path
* @param realBoltClassName the fully qualified JRuby bolt implementation class name
* @param fields the output fields names
*/
public JRubyTransactionalBolt(String baseClassPath, String realBoltClassName, String[] fields) {
_realBoltClassName = realBoltClassName;
_fields = fields;
_bootstrap = "require '" + baseClassPath + "'";
}
@Override
public void prepare(final Map conf, final TopologyContext context, final BatchOutputCollector collector, final TransactionAttempt id) {
_ruby_bolt = initialize_ruby_bolt();
IRubyObject ruby_conf = JavaUtil.convertJavaToRuby(__ruby__, conf);
IRubyObject ruby_context = JavaUtil.convertJavaToRuby(__ruby__, context);
IRubyObject ruby_collector = JavaUtil.convertJavaToRuby(__ruby__, collector);
IRubyObject ruby_id = JavaUtil.convertJavaToRuby(__ruby__, id);
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_bolt, "prepare", ruby_conf, ruby_context, ruby_collector, ruby_id);
}
@Override
public void execute(Tuple input) {
IRubyObject ruby_input = JavaUtil.convertJavaToRuby(__ruby__, input);
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_bolt, "execute", ruby_input);
}
@Override
public void finishBatch() {
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_bolt, "finish_batch");
}
@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
// declareOutputFields is executed in the topology creation time, before serialisation.
// just create tmp bolt instance to call declareOutputFields.
if (_fields.length > 0) {
declarer.declare(new Fields(_fields));
} else {
IRubyObject ruby_bolt = initialize_ruby_bolt();
IRubyObject ruby_declarer = JavaUtil.convertJavaToRuby(__ruby__, declarer);
Helpers.invoke(__ruby__.getCurrentContext(), ruby_bolt, "declare_output_fields", ruby_declarer);
}
}
@Override
public Map<String, Object> getComponentConfiguration() {
// getComponentConfiguration is executed in the topology creation time, before serialisation.
// just create tmp bolt instance to call getComponentConfiguration.
IRubyObject ruby_bolt = initialize_ruby_bolt();
IRubyObject ruby_result = Helpers.invoke(__ruby__.getCurrentContext(), ruby_bolt, "get_component_configuration");
return (Map)ruby_result.toJava(Map.class);
}
protected IRubyObject initialize_ruby_bolt() {
__ruby__ = Ruby.getGlobalRuntime();
RubyModule ruby_class;
try {
ruby_class = __ruby__.getClassFromPath(_realBoltClassName);
}
catch (RaiseException e) {
// after deserialization we need to recreate ruby environment
__ruby__.evalScriptlet(_bootstrap);
ruby_class = __ruby__.getClassFromPath(_realBoltClassName);
}
return Helpers.invoke(__ruby__.getCurrentContext(), ruby_class, "new");
}
}