Github user trkurc commented on a diff in the pull request:
https://github.com/apache/nifi/pull/1541#discussion_r123135376
--- Diff:
nifi-nar-bundles/nifi-irc-bundle/nifi-irc-processors/src/main/java/org/apache/nifi/processors/irc/handlers/ConsumerEventHandler.java
---
@@ -0,0 +1,127 @@
+/*
+ * 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.nifi.processors.irc.handlers;
+
+import net.engio.mbassy.listener.Handler;
+import net.engio.mbassy.listener.Invoke;
+import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ComponentLog;
+import org.apache.nifi.processor.ProcessContext;
+import org.apache.nifi.processor.ProcessSession;
+import org.apache.nifi.processor.ProcessSessionFactory;
+import org.apache.nifi.processor.exception.FlowFileAccessException;
+import org.apache.nifi.processor.io.OutputStreamCallback;
+import org.apache.nifi.processors.irc.ConsumeIRC;
+import org.apache.nifi.util.StopWatch;
+import org.kitteh.irc.client.library.event.channel.ChannelMessageEvent;
+import org.kitteh.irc.client.library.event.helper.MessageEvent;
+import org.kitteh.irc.client.library.event.user.PrivateMessageEvent;
+import org.kitteh.irc.client.library.util.Format;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+
+public class ConsumerEventHandler extends EventHandler {
+
+ public ConsumerEventHandler(ProcessContext context,
ProcessSessionFactory sessionFactory, ComponentLog logger) {
+ super(context, sessionFactory, logger);
+ }
+
+ @Handler(delivery = Invoke.Asynchronously)
+ protected void onPrivateMessageReceived(PrivateMessageEvent event) {
+ logger.info("Received private message '{}' from {} while waiting
for messages on {} ",
+ new Object[] {event.getMessage(),
event.getActor().getName(),
context.getProperty(ConsumeIRC.IRC_CHANNEL).getValue()});
+ if
(context.getProperty(ConsumeIRC.IRC_PROCESS_PRIV_MESSAGES).asBoolean()) {
+ turnEventIntoFlowFile(event);
+ } else {
+ event.sendReply(String.format("Hi %s. Thank you for your
message but I am not looking to chat with strangers.",
+ String.valueOf(event.getActor().getNick())));
+ }
+ }
+
+ @Handler(delivery = Invoke.Asynchronously)
+ protected void onChannelMessageReceived(ChannelMessageEvent event) {
+ // verify if the message was sent to the channel the processor is
consuming
+ if
(event.getChannel().getName().equals(context.getProperty(ConsumeIRC.IRC_CHANNEL).getValue()))
{
+
+ logger.info("Received message '{}' on channel {} while
waiting for messages on {} ",
+ new Object[]{event.getMessage(),
event.getChannel().getName(),
context.getProperty(ConsumeIRC.IRC_CHANNEL).getValue()});
+ turnEventIntoFlowFile(event);
+ }
+ }
+
+ private void turnEventIntoFlowFile(final MessageEvent messageEvent) {
--- End diff --
I'm not super familiar with this irc library, but I think that what is
going on here is a bit "unorthodox". I think that this irc client allows you to
register callbacks, and when a message arrives, it calls your callback. If I'm
reading this right this class has stashed away the session that was passed into
the first onTrigger(), and then used to create new flowfiles OUTSIDE the
onTrigger method of the processor, which is certainly not the pattern for most
of the other "GetX" processors I've seen (I've seen: create a queue between the
service and the processor, and when onTrigger() is called consumes from that
queue). @joewitt - do you have any cautionary tales about using ProcessSession
in this way?
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