/**
* Handle the incoming message.
* <P>
* Normal messages are enqueued.</P>
* <P>
* The FLUSH message type tells the Queue to write all
* stored messages to the ouptut PipeFitting, then
* return to normal enqueing operation.</P>
* <P>
* The SORT message type tells the Queue to sort all
* <I>subsequent</I> incoming messages by priority. If there
* are unflushed messages in the queue, they will not be
* sorted unless a new message is sent before the next FLUSH.
* Sorting-by-priority behavior continues even after a FLUSH,
* and can be turned off by sending a FIFO message, which is
* the default behavior for enqueue/dequeue.</P>
*
* @param IPipeMessage $message
* @return bool
*/
public function write(IPipeMessage $message)
{
$success = true;
switch ($message->getType()) {
// Store normal messages
case Message::NORMAL:
$this->store($message);
break;
// Flush the queue
// Flush the queue
case QueueControlMessage::FLUSH:
$success = $this->flush();
break;
// Put Queue into Priority Sort or FIFO mode
// Subsequent messages written to the queue
// will be affected. Sorted messages cannot
// be put back into FIFO order!
// Put Queue into Priority Sort or FIFO mode
// Subsequent messages written to the queue
// will be affected. Sorted messages cannot
// be put back into FIFO order!
case QueueControlMessage::SORT:
case QueueControlMessage::FIFO:
$this->mode = $message->getType();
break;
}
return $success;
}
/**
* Handle the incoming message.
* <P>
* If message type is normal, filter the message (unless in BYPASS mode)
* and write the result to the output pipe fitting if the filter
* operation is successful.</P>
*
* <P>
* The FilterControlMessage.SET_PARAMS message type tells the Filter
* that the message class is FilterControlMessage, which it
* casts the message to in order to retrieve the filter parameters
* object if the message is addressed to this filter.</P>
*
* <P>
* The FilterControlMessage.SET_FILTER message type tells the Filter
* that the message class is FilterControlMessage, which it
* casts the message to in order to retrieve the filter function.</P>
*
* <P>
* The FilterControlMessage.BYPASS message type tells the Filter
* that it should go into Bypass mode operation, passing all normal
* messages through unfiltered.</P>
*
* <P>
* The FilterControlMessage.FILTER message type tells the Filter
* that it should go into Filtering mode operation, filtering all
* normal normal messages before writing out. This is the default
* mode of operation and so this message type need only be sent to
* cancel a previous BYPASS message.</P>
*
* <P>
* The Filter only acts on the control message if it is targeted
* to this named filter instance. Otherwise it writes through to the
* output.</P>
*
* @param IPipeMessage $message
* @return Boolean True if the filter process does not throw an error and subsequent operations
* in the pipeline succede.
*/
public function write(IPipeMessage $message)
{
$outputMessage = null;
$success = true;
// Filter normal messages
switch ($message->getType()) {
case Message::NORMAL:
try {
if ($this->mode == FilterControlMessage::FILTER) {
$outputMessage = $this->applyFilter($message);
} else {
$outputMessage = $message;
}
$success = $this->output->write($outputMessage);
} catch (Exception $e) {
$success = false;
}
break;
// Accept parameters from control message
// Accept parameters from control message
case FilterControlMessage::SET_PARAMS:
if ($this->isTarget($message)) {
$this->setParams($message->getParams());
} else {
$success = $this->output->write($outputMessage);
}
break;
// Accept filter function from control message
// Accept filter function from control message
case FilterControlMessage::SET_FILTER:
if ($this->isTarget($message)) {
$this->setFilter($message->getFilter());
} else {
$success = $this->output->write($outputMessage);
}
break;
// Toggle between Filter or Bypass operational modes
// Toggle between Filter or Bypass operational modes
case FilterControlMessage::BYPASS:
case FilterControlMessage::FILTER:
if ($this->isTarget($message)) {
$this->mode = $message->getType();
} else {
$success = $this->output->write($outputMessage);
}
break;
// Write control messages for other fittings through
// Write control messages for other fittings through
default:
$success = $this->output->write($outputMessage);
}
return $success;
}
