package redstorm.storm.jruby;
import backtype.storm.spout.SpoutOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.IRichSpout;
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 JRubySpout class is a proxy class to the actual spout 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 spout class is instanciated in the open 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 JRubySpout implements IRichSpout {
private final String _realSpoutClassName;
private final String[] _fields;
private final String _bootstrap;
// transient to avoid serialization
private transient IRubyObject _ruby_spout;
private transient Ruby __ruby__;
/**
* create a new JRubySpout
*
* @param baseClassPath the topology/project base JRuby class file path
* @param realSpoutClassName the fully qualified JRuby spout implementation class name
* @param fields the output fields names
*/
public JRubySpout(String baseClassPath, String realSpoutClassName, String[] fields) {
_realSpoutClassName = realSpoutClassName;
_fields = fields;
_bootstrap = "require '" + baseClassPath + "'";
}
@Override
public void open(final Map conf, final TopologyContext context, final SpoutOutputCollector collector) {
_ruby_spout = initialize_ruby_spout();
IRubyObject ruby_conf = JavaUtil.convertJavaToRuby(__ruby__, conf);
IRubyObject ruby_context = JavaUtil.convertJavaToRuby(__ruby__, context);
IRubyObject ruby_collector = JavaUtil.convertJavaToRuby(__ruby__, collector);
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "open", ruby_conf, ruby_context, ruby_collector);
}
@Override
public void close() {
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "close");
}
@Override
public void activate() {
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "activate");
}
@Override
public void deactivate() {
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "deactivate");
}
@Override
public void nextTuple() {
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "next_tuple");
}
@Override
public void ack(Object msgId) {
IRubyObject ruby_msg_id = JavaUtil.convertJavaToRuby(__ruby__, msgId);
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "ack", ruby_msg_id);
}
@Override
public void fail(Object msgId) {
IRubyObject ruby_msg_id = JavaUtil.convertJavaToRuby(__ruby__, msgId);
Helpers.invoke(__ruby__.getCurrentContext(), _ruby_spout, "fail", ruby_msg_id);
}
@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
// declareOutputFields is executed in the topology creation time, before serialisation.
// just create tmp spout instance to call declareOutputFields.
if (_fields.length > 0) {
declarer.declare(new Fields(_fields));
} else {
IRubyObject ruby_spout = initialize_ruby_spout();
IRubyObject ruby_declarer = JavaUtil.convertJavaToRuby(__ruby__, declarer);
Helpers.invoke(__ruby__.getCurrentContext(), ruby_spout, "declare_output_fields", ruby_declarer);
}
}
@Override
public Map<String, Object> getComponentConfiguration() {
// getComponentConfiguration is executed in the topology creation time, before serialisation.
// just create tmp spout instance to call getComponentConfiguration.
IRubyObject ruby_spout = initialize_ruby_spout();
IRubyObject ruby_result = Helpers.invoke(__ruby__.getCurrentContext(), ruby_spout, "get_component_configuration");
return (Map)ruby_result.toJava(Map.class);
}
private IRubyObject initialize_ruby_spout() {
__ruby__ = Ruby.getGlobalRuntime();
RubyModule ruby_class;
try {
ruby_class = __ruby__.getClassFromPath(_realSpoutClassName);
}
catch (RaiseException e) {
// after deserialization we need to recreate ruby environment
__ruby__.evalScriptlet(_bootstrap);
ruby_class = __ruby__.getClassFromPath(_realSpoutClassName);
}
return Helpers.invoke(__ruby__.getCurrentContext(), ruby_class, "new");
}
}