com.threerings.admin.server.ConfigRegistry Maven / Gradle / Ivy
//
// $Id: ConfigRegistry.java 6407 2011-01-01 05:02:21Z dhoover $
//
// Narya library - tools for developing networked games
// Copyright (C) 2002-2011 Three Rings Design, Inc., All Rights Reserved
// http://code.google.com/p/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.admin.server;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import com.google.common.collect.Maps;
import com.samskivert.io.ByteArrayOutInputStream;
import com.samskivert.util.StringUtil;
import com.threerings.io.ObjectInputStream;
import com.threerings.io.ObjectOutputStream;
import com.threerings.io.Streamer;
import com.threerings.presents.dobj.AccessController;
import com.threerings.presents.dobj.AttributeChangeListener;
import com.threerings.presents.dobj.AttributeChangedEvent;
import com.threerings.presents.dobj.DObject;
import com.threerings.presents.dobj.DSet;
import com.threerings.presents.dobj.ElementUpdateListener;
import com.threerings.presents.dobj.ElementUpdatedEvent;
import com.threerings.presents.dobj.EntryAddedEvent;
import com.threerings.presents.dobj.EntryRemovedEvent;
import com.threerings.presents.dobj.EntryUpdatedEvent;
import com.threerings.presents.dobj.SetListener;
import static com.threerings.admin.Log.log;
/**
* Provides a registry of configuration distributed objects. Using distributed object to store
* runtime configuration data can be exceptionally useful in that clients (with admin privileges)
* can view and update the running server's configuration parameters on the fly.
*
* Users of the service are responsible for creating their own configuration objects which are
* then registered via this class. The config object registry then performs a few functions:
*
*
* - It populates the config object with values from the persistent configuration information.
*
- It mirrors object updates out to the persistent configuration repository.
*
- It makes the set of registered objects available for inspection and modification via the
* admin client interface.
*
*
* Users of this service will want to use {@link AccessController}s on their configuration
* distributed objects to prevent non-administrators from subscribing to or modifying the objects.
*/
public abstract class ConfigRegistry
{
/**
* Creates a ConfigRegistry that isn't transitioning.
*/
public ConfigRegistry ()
{
this(false);
}
/**
* Creates a ConfigRegistry.
*
* @param transitioning if true, serialized Streamable instances stored in the registry will
* be written back out immediately to allow them to be transitioned to new class names.
*/
public ConfigRegistry (boolean transitioning)
{
_transitioning = transitioning;
}
/**
* Registers the supplied configuration object with the system.
*
* @param key a string that identifies this object. These are generally hierarchical in nature
* (of the form system.subsystem), for example: yohoho.crew.
* @param path The the path in the persistent configuration repository. This may mean
* something to the underlying persistent store, for example in the preferences backed
* implementation it defines the path to the preferences node in the package hierarchy.
* @param object the object to be registered.
*/
public void registerObject (String key, String path, DObject object)
{
ObjectRecord record = createObjectRecord(path, object);
record.init();
_configs.put(key, record);
}
/**
* Returns the config object mapped to the specified key, or null if none exists for that key.
*/
public DObject getObject (String key)
{
ObjectRecord record = _configs.get(key);
return (record == null) ? null : record.object;
}
/**
* Returns an array containing the keys of all registered configuration objects.
*/
public String[] getKeys ()
{
return _configs.keySet().toArray(new String[_configs.size()]);
}
/**
* Creates an object record derivation that will handle the management of the specified object.
*/
protected abstract ObjectRecord createObjectRecord (String path, DObject object);
/**
* Create an ObjectInputStream to read serialized config entries.
*/
protected ObjectInputStream createObjectInputStream (InputStream bin)
{
return new ObjectInputStream(bin);
}
/**
* Create an ObjectOutputStream to write serialized config entries.
*/
protected ObjectOutputStream createObjectOutputStream (OutputStream bin)
{
return new ObjectOutputStream(bin);
}
/**
* Contains all necessary info for a configuration object registration.
*/
protected abstract class ObjectRecord
implements AttributeChangeListener, SetListener, ElementUpdateListener
{
public DObject object;
public ObjectRecord (DObject obj)
{
object = obj;
}
public void init ()
{
// read in the initial configuration settings from the persistent config repository
Class cclass = object.getClass();
try {
Field[] fields = cclass.getFields();
for (Field field : fields) {
int mods = field.getModifiers();
if ((mods & Modifier.STATIC) != 0 || (mods & Modifier.PUBLIC) == 0 ||
(mods & Modifier.TRANSIENT) != 0) {
continue;
}
initField(field);
}
// listen for attribute updates
object.addListener(this);
} catch (SecurityException se) {
log.warning("Unable to reflect on " + cclass.getName() + ": " + se + ". " +
"Refusing to monitor object.");
}
}
// from SetListener
public void entryAdded (EntryAddedEvent event)
{
serializeAttribute(event.getName());
}
// from SetListener
public void entryUpdated (EntryUpdatedEvent event)
{
serializeAttribute(event.getName());
}
// from SetListener
public void entryRemoved (EntryRemovedEvent event)
{
serializeAttribute(event.getName());
}
// from ElementUpdateListener
public void elementUpdated (ElementUpdatedEvent event)
{
updateValue(event.getName(), object.getAttribute(event.getName()));
}
// from AttributeChangeListener
public void attributeChanged (AttributeChangedEvent event)
{
// mirror this configuration update to the persistent config
updateValue(event.getName(), event.getValue());
}
protected void updateValue (String name, Object value)
{
String key = nameToKey(name);
if (value instanceof Boolean) {
setValue(key, ((Boolean)value).booleanValue());
} else if (value instanceof Byte) {
setValue(key, ((Byte)value).byteValue());
} else if (value instanceof Short) {
setValue(key, ((Short)value).shortValue());
} else if (value instanceof Integer) {
setValue(key, ((Integer)value).intValue());
} else if (value instanceof Long) {
setValue(key, ((Long)value).longValue());
} else if (value instanceof Float) {
setValue(key, ((Float)value).floatValue());
} else if (value instanceof String) {
setValue(key, (String)value);
} else if (value instanceof float[]) {
setValue(key, (float[])value);
} else if (value instanceof int[]) {
setValue(key, (int[])value);
} else if (value instanceof String[]) {
setValue(key, (String[])value);
} else if (value instanceof long[]) {
setValue(key, (long[])value);
} else if (value == null || Streamer.isStreamable(value.getClass())) {
serializeAttribute(name);
} else {
log.info("Unable to flush config obj change", "cobj", object.getClass().getName(),
"key", key, "type", value.getClass().getName(), "value", value);
}
}
/**
* Initializes a single field of a config distributed object from its corresponding value
* in the associated config repository.
*/
protected void initField (Field field)
{
String key = nameToKey(field.getName());
Class type = field.getType();
try {
if (type.equals(Boolean.TYPE)) {
boolean defval = field.getBoolean(object);
field.setBoolean(object, getValue(key, defval));
} else if (type.equals(Byte.TYPE)) {
byte defval = field.getByte(object);
field.setByte(object, getValue(key, defval));
} else if (type.equals(Short.TYPE)) {
short defval = field.getShort(object);
field.setShort(object, getValue(key, defval));
} else if (type.equals(Integer.TYPE)) {
int defval = field.getInt(object);
field.setInt(object, getValue(key, defval));
} else if (type.equals(Long.TYPE)) {
long defval = field.getLong(object);
field.setLong(object, getValue(key, defval));
} else if (type.equals(Float.TYPE)) {
float defval = field.getFloat(object);
field.setFloat(object, getValue(key, defval));
} else if (type.equals(String.class)) {
String defval = (String)field.get(object);
field.set(object, getValue(key, defval));
} else if (type.equals(int[].class)) {
int[] defval = (int[])field.get(object);
field.set(object, getValue(key, defval));
} else if (type.equals(float[].class)) {
float[] defval = (float[])field.get(object);
field.set(object, getValue(key, defval));
} else if (type.equals(String[].class)) {
String[] defval = (String[])field.get(object);
field.set(object, getValue(key, defval));
} else if (type.equals(long[].class)) {
long[] defval = (long[])field.get(object);
field.set(object, getValue(key, defval));
} else if (Streamer.isStreamable(type)) {
// don't freak out if the conf is blank.
String value = getValue(key, "");
if (StringUtil.isBlank(value)) {
return;
}
try {
Object deserializedValue = deserialize(value);
field.set(object, deserializedValue);
if (_transitioning) {
// Use serialize rather than serializeAttribute so we don't get
// ObjectAccessExceptions
serialize(key, nameToKey(key), deserializedValue);
}
} catch (Exception e) {
log.warning("Failure decoding config value", "type", type, "field", field,
"exception", e);
}
} else {
log.warning("Can't init field of unknown type",
"cobj", object.getClass().getName(), "key", key,
"type", type.getName());
}
} catch (IllegalAccessException iae) {
log.warning("Can't set field", "cobj", object.getClass().getName(), "key", key,
"error", iae);
}
}
/**
* Get the specified attribute from the configuration object, and serialize it.
*/
protected void serializeAttribute (String attributeName)
{
String key = nameToKey(attributeName);
Object value = object.getAttribute(attributeName);
if (value == null || Streamer.isStreamable(value.getClass())) {
serialize(attributeName, key, value);
} else {
log.info("Unable to flush config obj change", "cobj", object.getClass().getName(),
"key", key, "type", value.getClass().getName(), "value", value);
}
}
/**
* Save the specified object as serialized data associated with the specified key.
*/
protected void serialize (String name, String key, Object value)
{
ByteArrayOutInputStream out = new ByteArrayOutInputStream();
ObjectOutputStream oout = createObjectOutputStream(out);
try {
oout.writeObject(value);
oout.flush();
setValue(key, StringUtil.hexlate(out.toByteArray()));
} catch (IOException ioe) {
log.info("Error serializing value " + value);
}
}
/**
* Deserializes the object contained in the specified string.
*/
protected Object deserialize (String value)
throws Exception
{
ByteArrayInputStream bin = new ByteArrayInputStream(StringUtil.unhexlate(value));
ObjectInputStream oin = createObjectInputStream(bin);
return oin.readObject();
}
/**
* Converts a config object field name (someConfigMember) to a configuration key
* (some_config_member).
*/
protected String nameToKey (String attributeName)
{
return StringUtil.unStudlyName(attributeName).toLowerCase();
}
protected abstract boolean getValue (String field, boolean defval);
protected abstract byte getValue (String field, byte defval);
protected abstract short getValue (String field, short defval);
protected abstract int getValue (String field, int defval);
protected abstract long getValue (String field, long defval);
protected abstract float getValue (String field, float defval);
protected abstract String getValue (String field, String defval);
protected abstract int[] getValue (String field, int[] defval);
protected abstract float[] getValue (String field, float[] defval);
protected abstract long[] getValue (String field, long[] defval);
protected abstract String[] getValue (String field, String[] defval);
protected abstract void setValue (String field, boolean value);
protected abstract void setValue (String field, byte value);
protected abstract void setValue (String field, short value);
protected abstract void setValue (String field, int value);
protected abstract void setValue (String field, long value);
protected abstract void setValue (String field, float value);
protected abstract void setValue (String field, String value);
protected abstract void setValue (String field, int[] value);
protected abstract void setValue (String field, float[] value);
protected abstract void setValue (String field, long[] value);
protected abstract void setValue (String field, String[] value);
}
/** A mapping from identifying key to config object. */
protected HashMap _configs = Maps.newHashMap();
/** If we need to transition serialized Streamables to a new class format in init.. */
protected boolean _transitioning;
}