/**
* Instantiate a message
*
* @param type {@link MessageType} as a string or a custom message type
* @param msgId unique message identifier
*/
public Message(String type, MessageId msgId) {
super(new ZNRecord(msgId.stringify()));
_record.setSimpleField(Attributes.MSG_TYPE.toString(), type);
setMessageId(msgId);
setMsgState(MessageState.NEW);
_record.setLongField(Attributes.CREATE_TIMESTAMP.toString(), new Date().getTime());
}
/**
* Instantiate a message
*
* @param record a ZNRecord corresponding to a message
*/
public Message(ZNRecord record) {
super(record);
if (getMsgState() == null) {
setMsgState(MessageState.NEW);
}
if (getCreateTimeStamp() == 0) {
_record.setLongField(Attributes.CREATE_TIMESTAMP.toString(), new Date().getTime());
}
}
/**
* Create a reply based on an incoming message
*
* @param srcMessage the incoming message
* @param instanceName the instance that is the source of the reply
* @param taskResultMap the result of executing the incoming message
* @return the reply Message
*/
public static Message createReplyMessage(
Message srcMessage, String instanceName, Map<String, String> taskResultMap) {
if (srcMessage.getCorrelationId() == null) {
throw new HelixException(
"Message " + srcMessage.getMessageId() + " does not contain correlation id");
}
Message replyMessage =
new Message(MessageType.TASK_REPLY, MessageId.from(UUID.randomUUID().toString()));
replyMessage.setCorrelationId(srcMessage.getCorrelationId());
replyMessage.setResultMap(taskResultMap);
replyMessage.setTgtSessionId(SessionId.from("*"));
replyMessage.setMsgState(MessageState.NEW);
replyMessage.setSrcName(instanceName);
if (srcMessage.getSrcInstanceType() == InstanceType.CONTROLLER) {
replyMessage.setTgtName("Controller");
} else {
replyMessage.setTgtName(srcMessage.getMsgSrc());
}
return replyMessage;
}