SK.gnome.dwarf.mail.smtp
Class FileMailQueue

java.lang.Object
  SK.gnome.dwarf.GenericService
      SK.gnome.dwarf.thread.ThreadService
          SK.gnome.dwarf.mail.smtp.FileMailQueue

All Implemented Interfaces:

MailQueue, java.lang.Runnable, SK.gnome.dwarf.Service

public class FileMailQueue

extends SK.gnome.dwarf.thread.ThreadService

implements MailQueue

Provides filesystem-based mail queue.

The queue is stored in a special directory which must be set via the setQueueDir(File) method. It contains two subdirectories "msgs" and "nodes". The first one stores messages and the second one node queues. Each message is represented by a subdirectory with name equal to the message's SMTP identification string. (Subdirectories starting with dot are regarded temporary and deleted automatically after some time.) Each subdirectory contains serialized form of the SMTP envelope data in file named ".control" and the raw message data in file named ".message". In addition, there are one or more files with the serialized form of each message recipient named "xxxx@some.domain.com", where xxxx is hexadecimal value of the hashed recipient's address.

The "nodes" subdirectory contains the scheduling information for all nodes, which are in fact domain names of all recipients of all messages in the queue. Each node is represented by a single subdirectory containing references to all messages enqueued for this particular node. A reference is a zero-length file with name "xxxxx-yyyyy-zzzzz", where the first part is message's SMTP identification string, the second part is Node identification used for enqueueing the message, and the third one is a time in milliseconds for which the message had been enqueued. Zero time means that the message should be dequeued as soon as possible, probably in the very next queue run.

If a message with SMTP id 123671263817_32398 is enqueued for delivery to "joe@public.com" by a Node with 1242482349_09312 id, for example, the "nodes/public.com" subdirectory must contain a file named "123671263817_32398-1232482349_09312-1233074634323", where the last number is time after which message may be dequeued for further processing.

Note: since the serialized queue objects contains also paths to files, it is not safe to move the queue content to another location.

Field Summary

Fields inherited from class SK.gnome.dwarf.thread.ThreadService

daemon, thread

Fields inherited from class SK.gnome.dwarf.GenericService

initParameters, parent

Fields inherited from interface SK.gnome.dwarf.Service

INITIALIZED, LOG_DEBUG, LOG_ERROR, LOG_FATAL, LOG_INFO, LOG_TRACE, LOG_WARN, LOG_XFER, SHUTDOWN, STARTED, STOPPED

Constructor Summary

FileMailQueue(java.lang.String name)

Method Summary

SMTPMessage	dequeueMessage(Node node) Dequeues a message for the given node.
protected boolean	enableThread()
void	enqueueMessage(SMTPMessage message, Node node, long time) Enqueues the message for the given node and time.
SMTPMessage	getMessageInstance() Returns a new SMTPMessage instance.
void	init(SK.gnome.dwarf.Server parent)
void	listMessages(boolean details, java.io.PrintWriter out) Lists all messages in the queue.
java.util.Iterator	listNodes() Lists all active nodes.
protected void	loop()
void	setDeleteFinished(boolean enable)
void	setCheckpoint(int time)
void	setQueueDir(java.io.File dir)

Methods inherited from class SK.gnome.dwarf.thread.ThreadService

finish, run, setDaemon, shutdown, start, stop

Methods inherited from class SK.gnome.dwarf.GenericService

getAuthenticator, getAuthFacility, getFullName, getInitParameter, getInitParameterNames, getLogFacility, getLogger, getName, getParameters, getPrincipal, getShutdownTimeout, getState, log, log, login, logout, setAuthFacility, setInitParameters, setLogFacility, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FileMailQueue

public FileMailQueue(java.lang.String name)

Method Detail

setQueueDir

public void setQueueDir(java.io.File dir)

setCheckpoint

public void setCheckpoint(int time)

setDeleteFinished

public void setDeleteFinished(boolean enable)

init

public void init(SK.gnome.dwarf.Server parent)
          throws SK.gnome.dwarf.ServiceException

Specified by:

init in interface SK.gnome.dwarf.Service

Throws:

SK.gnome.dwarf.ServiceException

getMessageInstance

public SMTPMessage getMessageInstance()
                               throws MailException

Description copied from interface: MailQueue

Returns a new SMTPMessage instance.

Specified by:

getMessageInstance in interface MailQueue

Returns:

the new message instance

Throws:

MailException - if an error occured

listMessages

public void listMessages(boolean details,
                         java.io.PrintWriter out)
                  throws MailException

Description copied from interface: MailQueue

Lists all messages in the queue.

A short or detailed information is printed out about each message waiting in the queue.

Specified by:

listMessages in interface MailQueue

Parameters:

details - true to print message details, false otherwise

out - the output stream

Throws:

MailException - if an error occured

enqueueMessage

public void enqueueMessage(SMTPMessage message,
                           Node node,
                           long time)
                    throws MailException

Description copied from interface: MailQueue

Enqueues the message for the given node and time.

The message as well as its recipient collection are stored to the mail queue and may be returned later via the MailQueue.dequeueMessage(Node) method, if the recipients are targeted for the given node and other conditions are met, too. In other words, the message is scheduled to be processed for the given node at the specified time.

Specified by:

enqueueMessage in interface MailQueue

Parameters:

message - the message

node - the node to enqueue the message for

time - the time for next processing or delivery attempt

Throws:

MailException - if an error occured

dequeueMessage

public SMTPMessage dequeueMessage(Node node)
                           throws MailException

Description copied from interface: MailQueue

Dequeues a message for the given node.

Only those messages may be returned which had been enqueued for the given node and time less or equal the current system time, unless the node's Node.getForceDelivery() returns true. Furthemore, messages which had been already processed for the same Node object previously must not be returned. A returned message's SMTPMessage.getRecipients() method may return only those recipients which are targeted for the given node. After dequeueing the recipients are removed from the queue processing and may be included in it again only by calling MailQueue.enqueueMessage(SMTPMessage, Node, long) on the same message object.

Specified by:

dequeueMessage in interface MailQueue

Parameters:

node - the node to dequeue a message for

Returns:

the message or null if no message waits for the processing

Throws:

MailException - if an error occured

listNodes

public java.util.Iterator listNodes()

Description copied from interface: MailQueue

Lists all active nodes.

A node is active only if it contains any messages for processing. The returned iteration contains java.lang.String objects with the node names.

Specified by:

listNodes in interface MailQueue

Returns:

the iteration of active nodes

enableThread

protected boolean enableThread()

loop

protected void loop()