/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: DummyPreferences.java
*
* Copyright (c) 2007 Sun Microsystems and Static Free Software
*
* Electric(tm) 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; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) 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 Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.sandbox;
import java.util.HashMap;
import java.util.prefs.AbstractPreferences;
import java.util.prefs.BackingStoreException;
/**
* Dummy implementation of Preferebces class.
*/
public class DummyPreferences extends AbstractPreferences {
private HashMap<String,String> items = new HashMap<String,String>();
/** Creates a new instance of MyPrefernces */
protected DummyPreferences(AbstractPreferences parent, String name) {
super(parent, name);
}
// "SPI" METHODS
/**
* Put the given key-value association into this preference node. It is
* guaranteed that <tt>key</tt> and <tt>value</tt> are non-null and of
* legal length. Also, it is guaranteed that this node has not been
* removed. (The implementor needn't check for any of these things.)
*
* <p>This method is invoked with the lock on this node held.
*/
protected void putSpi(String key, String value) {
// System.out.println("MyPreferences putSpi " + absolutePath() + " " + key + " " + value);
items.put(key, value);
}
/**
* Return the value associated with the specified key at this preference
* node, or <tt>null</tt> if there is no association for this key, or the
* association cannot be determined at this time. It is guaranteed that
* <tt>key</tt> is non-null. Also, it is guaranteed that this node has
* not been removed. (The implementor needn't check for either of these
* things.)
*
* <p> Generally speaking, this method should not throw an exception
* under any circumstances. If, however, if it does throw an exception,
* the exception will be intercepted and treated as a <tt>null</tt>
* return value.
*
* <p>This method is invoked with the lock on this node held.
*
* @return the value associated with the specified key at this preference
* node, or <tt>null</tt> if there is no association for this
* key, or the association cannot be determined at this time.
*/
protected String getSpi(String key) {
// System.out.println("MyPreferences getSpi " + absolutePath() + " " + key);
return items.get(key);
}
/**
* Remove the association (if any) for the specified key at this
* preference node. It is guaranteed that <tt>key</tt> is non-null.
* Also, it is guaranteed that this node has not been removed.
* (The implementor needn't check for either of these things.)
*
* <p>This method is invoked with the lock on this node held.
*/
protected void removeSpi(String key) {
System.out.println("MyPreferences removeSpi " + absolutePath() + " " + key);
items.remove(key);
}
/**
* Removes this preference node, invalidating it and any preferences that
* it contains. The named child will have no descendants at the time this
* invocation is made (i.e., the {@link java.util.prefs.Preferences#removeNode()} method
* invokes this method repeatedly in a bottom-up fashion, removing each of
* a node's descendants before removing the node itself).
*
* <p>This method is invoked with the lock held on this node and its
* parent (and all ancestors that are being removed as a
* result of a single invocation to {@link java.util.prefs.Preferences#removeNode()}).
*
* <p>The removal of a node needn't become persistent until the
* <tt>flush</tt> method is invoked on this node (or an ancestor).
*
* <p>If this node throws a <tt>BackingStoreException</tt>, the exception
* will propagate out beyond the enclosing {@link #removeNode()}
* invocation.
*
* @throws BackingStoreException if this operation cannot be completed
* due to a failure in the backing store, or inability to
* communicate with it.
*/
protected void removeNodeSpi() throws BackingStoreException {
// System.out.println("MyPreferences.removeNodeSpi " + absolutePath());
}
/**
* Returns all of the keys that have an associated value in this
* preference node. (The returned array will be of size zero if
* this node has no preferences.) It is guaranteed that this node has not
* been removed.
*
* <p>This method is invoked with the lock on this node held.
*
* <p>If this node throws a <tt>BackingStoreException</tt>, the exception
* will propagate out beyond the enclosing {@link #keys()} invocation.
*
* @return an array of the keys that have an associated value in this
* preference node.
* @throws BackingStoreException if this operation cannot be completed
* due to a failure in the backing store, or inability to
* communicate with it.
*/
protected String[] keysSpi() throws BackingStoreException {
return items.keySet().toArray(new String[items.size()]);
}
private final static String[] EMPTY_STRING_ARRAY = new String[0];
/**
* Returns the names of the children of this preference node. (The
* returned array will be of size zero if this node has no children.)
* This method need not return the names of any nodes already cached,
* but may do so without harm.
*
* <p>This method is invoked with the lock on this node held.
*
* <p>If this node throws a <tt>BackingStoreException</tt>, the exception
* will propagate out beyond the enclosing {@link #childrenNames()}
* invocation.
*
* @return an array containing the names of the children of this
* preference node.
* @throws BackingStoreException if this operation cannot be completed
* due to a failure in the backing store, or inability to
* communicate with it.
*/
protected String[] childrenNamesSpi() throws BackingStoreException {
return EMPTY_STRING_ARRAY;
}
/**
* Returns the named child of this preference node, creating it if it does
* not already exist. It is guaranteed that <tt>name</tt> is non-null,
* non-empty, does not contain the slash character ('/'), and is no longer
* than {@link #MAX_NAME_LENGTH} characters. Also, it is guaranteed that
* this node has not been removed. (The implementor needn't check for any
* of these things.)
*
* <p>Finally, it is guaranteed that the named node has not been returned
* by a previous invocation of this method or {@link #getChild(String)}
* after the last time that it was removed. In other words, a cached
* value will always be used in preference to invoking this method.
* Subclasses need not maintain their own cache of previously returned
* children.
*
* <p>The implementer must ensure that the returned node has not been
* removed. If a like-named child of this node was previously removed, the
* implementer must return a newly constructed <tt>AbstractPreferences</tt>
* node; once removed, an <tt>AbstractPreferences</tt> node
* cannot be "resuscitated."
*
* <p>If this method causes a node to be created, this node is not
* guaranteed to be persistent until the <tt>flush</tt> method is
* invoked on this node or one of its ancestors (or descendants).
*
* <p>This method is invoked with the lock on this node held.
*
* @param name The name of the child node to return, relative to
* this preference node.
* @return The named child node.
*/
protected AbstractPreferences childSpi(String name) {
return new DummyPreferences(this, name);
}
/**
* This method is invoked with this node locked. The contract of this
* method is to synchronize any cached preferences stored at this node
* with any stored in the backing store. (It is perfectly possible that
* this node does not exist on the backing store, either because it has
* been deleted by another VM, or because it has not yet been created.)
* Note that this method should <i>not</i> synchronize the preferences in
* any subnodes of this node. If the backing store naturally syncs an
* entire subtree at once, the implementer is encouraged to override
* sync(), rather than merely overriding this method.
*
* <p>If this node throws a <tt>BackingStoreException</tt>, the exception
* will propagate out beyond the enclosing {@link #sync()} invocation.
*
* @throws BackingStoreException if this operation cannot be completed
* due to a failure in the backing store, or inability to
* communicate with it.
*/
protected void syncSpi() throws BackingStoreException {
System.out.println("MyPreferences.syncSpi");
}
/**
* This method is invoked with this node locked. The contract of this
* method is to force any cached changes in the contents of this
* preference node to the backing store, guaranteeing their persistence.
* (It is perfectly possible that this node does not exist on the backing
* store, either because it has been deleted by another VM, or because it
* has not yet been created.) Note that this method should <i>not</i>
* flush the preferences in any subnodes of this node. If the backing
* store naturally flushes an entire subtree at once, the implementer is
* encouraged to override flush(), rather than merely overriding this
* method.
*
* <p>If this node throws a <tt>BackingStoreException</tt>, the exception
* will propagate out beyond the enclosing {@link #flush()} invocation.
*
* @throws BackingStoreException if this operation cannot be completed
* due to a failure in the backing store, or inability to
* communicate with it.
*/
protected void flushSpi() throws BackingStoreException {
// System.out.println("MyPreferences.flushSpi");
}
}