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Moved Lifecycle to samskivert (my initial desire to do this came from a

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non-work project). I promise to stop fooling around now.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5805 542714f4-19e9-0310-aa3c-eee0fc999fb1
This commit is contained in:
Michael Bayne
2009-05-27 19:16:49 +00:00
parent e87c86dc2c
commit 3f19fcacf2
11 changed files with 9 additions and 353 deletions
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src/java/com/threerings/presents/util/Lifecycle.java
-176
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@@ -1,176 +0,0 @@
//
// $Id$
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2008 Three Rings Design, Inc., All Rights Reserved
// http://www.threerings.net/code/narya/
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published
// by the Free Software Foundation; either version 2.1 of the License, or
// (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package com.threerings.util;
import com.google.inject.Inject;
import com.samskivert.util.ObserverList;
import com.threerings.util.DependencyGraph;
import static com.threerings.presents.Log.log;
/**
* Manages the lifecycle (initialization and shutdown) of a collection of components.
*/
public class Lifecycle
{
/** An interface implemented by components which wish to participate in the lifecycle. */
public interface BaseComponent
{
}
/** An interface implemented by components which wish to participate in the lifecycle. */
public interface InitComponent extends BaseComponent
{
/** Called after dependencies have been fully resolved to initialize this component. */
public void init ();
}
/** An interface implemented by components which wish to participate in the lifecycle. */
public interface ShutdownComponent extends BaseComponent
{
/** Called when the server is shutting down. */
public void shutdown ();
}
/** An interface implemented by components which wish to participate in the lifecycle. */
public interface Component extends InitComponent, ShutdownComponent
{
}
/** Constraints for use with {@link #addConstraint}. */
public static enum Constraint { RUNS_BEFORE, RUNS_AFTER };
/**
* Registers a component with the lifecycle. This should be done during dependency resolution
* by injecting the Lifecycle into your constructor and calling this method there.
*/
public void addComponent (BaseComponent comp)
{
if (_initers == null || _downers == null) {
throw new IllegalStateException("Too late to register component.");
}
if (comp instanceof InitComponent) {
_initers.add((InitComponent)comp);
}
if (comp instanceof ShutdownComponent) {
_downers.add((ShutdownComponent)comp);
}
}
/**
* Removes a component from the lifecycle. This is generally not used.
*/
public void removeComponent (BaseComponent comp)
{
if (_initers != null && comp instanceof InitComponent) {
_initers.remove((InitComponent)comp);
}
if (_downers != null && comp instanceof ShutdownComponent) {
_downers.remove((ShutdownComponent)comp);
}
}
/**
* Adds a constraint that a certain component must be initialized before another.
*/
public void addInitConstraint (InitComponent lhs, Constraint constraint, InitComponent rhs)
{
if (lhs == null || rhs == null) {
throw new IllegalArgumentException("Cannot add constraint about null component.");
}
InitComponent before = (constraint == Constraint.RUNS_BEFORE) ? lhs : rhs;
InitComponent after = (constraint == Constraint.RUNS_BEFORE) ? rhs : lhs;
_initers.addDependency(after, before);
}
/**
* Adds a constraint that a certain component must be shutdown before another.
*/
public void addShutdownConstraint (ShutdownComponent lhs, Constraint constraint,
ShutdownComponent rhs)
{
if (lhs == null || rhs == null) {
throw new IllegalArgumentException("Cannot add constraint about null component.");
}
ShutdownComponent before = (constraint == Constraint.RUNS_BEFORE) ? lhs : rhs;
ShutdownComponent after = (constraint == Constraint.RUNS_BEFORE) ? rhs : lhs;
_downers.addDependency(after, before);
}
/**
* Returns true if we're in the process of shutting down.
*/
public boolean isShuttingDown ()
{
return (_downers == null);
}
/**
* Initializes all components immediately on the caller's thread.
*/
public void init ()
{
if (_initers == null) {
log.warning("Refusing repeat init() request.");
return;
}
ObserverList<InitComponent> list = _initers.toObserverList();
_initers = null;
list.apply(new ObserverList.ObserverOp<InitComponent>() {
public boolean apply (InitComponent comp) {
log.debug("Initializing component", "comp", comp);
comp.init();
return true;
}
});
}
/**
* Shuts down all components immediately on the caller's thread.
*/
public void shutdown ()
{
if (_downers == null) {
log.warning("Refusing repeat shutdown() request.");
return;
}
ObserverList<ShutdownComponent> list = _downers.toObserverList();
_downers = null;
list.apply(new ObserverList.ObserverOp<ShutdownComponent>() {
public boolean apply (ShutdownComponent comp) {
log.debug("Shutting down component", "comp", comp);
comp.shutdown();
return true;
}
});
}
/** A dependency graph of our components arranged by initialization dependencies. */
protected DependencyGraph<InitComponent> _initers = new DependencyGraph<InitComponent>();
/** A dependency graph of our components arranged by shutdown dependencies. */
protected DependencyGraph<ShutdownComponent> _downers =
new DependencyGraph<ShutdownComponent>();
}