/**
* Output an instance after filtering and remove from the output queue.
*
* @return the instance that has most recently been filtered (or null if the queue is empty).
* @exception NullPointerException if no output structure has been defined
*/
public M5Instance output() {
if (m_OutputFormat == null) {
throw new NullPointerException("No output instance format defined");
}
if (m_OutputQueue.empty()) {
return null;
}
M5Instance result = (M5Instance) m_OutputQueue.pop();
// Clear out references to old strings occasionally
if (m_OutputQueue.empty() && m_NewBatch) {
if (m_OutputStringAtts.length > 0) {
m_OutputFormat = m_OutputFormat.stringFreeStructure();
}
}
return result;
}
/**
* Output an instance after filtering but do not remove from the output queue.
*
* @return the instance that has most recently been filtered (or null if the queue is empty).
* @exception NullPointerException if no input structure has been defined
*/
public M5Instance outputPeek() {
if (m_OutputFormat == null) {
throw new NullPointerException("No output instance format defined");
}
if (m_OutputQueue.empty()) {
return null;
}
M5Instance result = (M5Instance) m_OutputQueue.peek();
return result;
}
// Return true if there is a message in the queue
public boolean hasMessage() {
return !messageQueue.empty();
}