/*
* RHQ Management Platform
* Copyright (C) 2005-2008 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.rhq.enterprise.communications.command.server;
import org.rhq.enterprise.communications.command.CommandType;
/**
* The public interface to the directory that provides information on what {@link CommandType command types} a
* particular {@link CommandServiceMBean command service} supports.
*
* <p>If a command type is supported by a command service, it is said that the command service is a <i>provider</i> of
* that command type.</p>
*
* <p>Each command service belongs to a particular subsystem - a subsystem is made up of one or more command services.
* Subsystems are identified by simple <code>String</code> names - with the unnamed, anonymous subsystem being
* identified by the <code>null</code> subsystem name.</p>
*
* @author John Mazzitelli
*/
public interface CommandServiceDirectoryMBean {
/**
* Given a particular {@link CommandType} and subsystem, this method will return an entry that gives you the <code>
* ObjectName</code> to a {@link CommandServiceMBean command service} that provides support for that command type
* within that subsystem.
*
* <p>If no command service provider exists for the given command type within the given subsystem, <code>null</code>
* is returned.</p>
*
* <p><code>subsystem</code> may be <code>null</code> to denote the unnamed, anonymous subsystem.</p>
*
* @param subsystem the subsystem to look in (may be <code>null</code>)
* @param commandType find a provider for this command type
*
* @return the entry that indicates the name of the subsystem's command service that provides support for the given
* command type, or <code>null</code> if no provider exists
*/
CommandServiceDirectoryEntry getCommandTypeProvider(String subsystem, CommandType commandType);
/**
* Given a subsystem, this will return all the entries for that subsystem - in other words, all the supported
* command types and the command services that provide them.
*
* <p>If no command service providers exists for the given subsystem, an empty array is returned.</p>
*
* <p><code>subsystem</code> may be <code>null</code> to denote the unnamed, anonymous subsystem.</p>
*
* @param subsystem the subsystem to look in (may be <code>null</code>)
*
* @return array of all entries for the given subsystem
*/
CommandServiceDirectoryEntry[] getSubsystemEntries(String subsystem);
/**
* This will return all the entries for all subsystems - in other words, all the supported command types and the
* command services that provide them in all subsystems.
*
* <p>If no command service providers exists, an empty array is returned.</p>
*
* @return array of all entries in the directory
*/
CommandServiceDirectoryEntry[] getAllEntries();
/**
* This attribute will indicate if new commands are allowed to be added dynamically at runtime. If <code>
* false</code>, only those command services currently installed at the time of this directory's registration will
* be found in the directory. If <code>true</code>, the directory will add new command services to the directory as
* they come online.
*
* <p>Note that this has no effect on dynamically discovering the <i>removal</i> of command services. The directory
* will always detect the removal of commands and remove their entries from the directory.</p>
*
* @return <code>true</code> will allow the directory to discovery changes during runtime. <code>false</code> means
* only those command services already in existence at the time the directory service is registered will be
* stored in the directory.
*/
boolean getAllowDynamicDiscovery();
/**
* This attribute will indicate if new commands are allowed to be added dynamically at runtime. If <code>
* false</code>, only those command services currently installed at the time of this directory's registration will
* be found in the directory. If <code>true</code>, the directory will add new command services to the directory as
* they come online.
*
* <p>Note that this has no effect on dynamically discovering the <i>removal</i> of command services. The directory
* will always detect the removal of commands and remove their entries from the directory.</p>
*
* @param flag <code>true</code> will allow the directory to discovery changes during runtime. <code>false</code>
* means only those command services already in existence at the time the directory service is
* registered will be stored in the directory.
*/
void setAllowDynamicDiscovery(boolean flag);
}