at.spardat.xma.mdl.util.TransNumber Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2003, 2010 s IT Solutions AT Spardat GmbH .
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* s IT Solutions AT Spardat GmbH - initial API and implementation
*******************************************************************************/
// @(#) $Id: $
package at.spardat.xma.mdl.util;
import java.io.IOException;
import at.spardat.xma.mdl.Synchronization;
import at.spardat.xma.mdl.Transactional;
import at.spardat.xma.serializer.XmaInput;
import at.spardat.xma.serializer.XmaOutput;
/**
* Encapsulates a numeric value and adds Transactional and XMA-Synchronization behavior.
* It can be used for byte, short, int and long.
* The desired type is given to the constructor.
* The type is used during synchronization.
*
* @author gub
* @since 2.3.0
*/
public final class TransNumber implements Transactional, Synchronization, Descriptive {
/** treat the value as byte */
public static final byte T_BYTE=1;
/** treat the value as short */
public static final byte T_SHORT=2;
/** treat the value as int */
public static final byte T_INT=3;
/** treat the value as long */
public static final byte T_LONG=4;
/** logical type of value */
byte type;
/** the current value */
long value;
/** the value at the last syncpoint. May only be accessed if hasHistory is true.*/
long saved;
/** indicates that saved contains a saved state */
boolean hasHistory=false;
/**
* Constructs a TransNumber.
* @param type the logical type of the value
* @param value the initial value
*/
public TransNumber(byte type,long value) {
this.type=type;
this.value=value;
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Transactional#changed()
*/
public boolean changed() {
return hasHistory;
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Transactional#commit()
*/
public void commit() {
saved=0;
hasHistory=false;
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Transactional#rollback()
*/
public void rollback() {
if(hasHistory) {
value=saved;
hasHistory=false;
}
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Synchronization#externalize(XmaOutput,boolean)
*/
public void externalize(XmaOutput xo, boolean forceFull) throws IOException {
switch(type) {
case T_BYTE: xo.writeByte("byte", (byte)value); break;
case T_SHORT: xo.writeShort("short", (short)value); break;
case T_INT: xo.writeInt("short", (int)value); break;
case T_LONG: xo.writeLong("short", (long)value); break;
}
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Synchronization#internalize(XmaInput)
*/
public void internalize(XmaInput in) throws IOException {
switch(type) {
case T_BYTE: value =in.readByte(); break;
case T_SHORT: value =in.readShort(); break;
case T_INT: value =in.readInt(); break;
case T_LONG: value =in.readLong(); break;
}
saved=0;
hasHistory=false;
}
/* (non-Javadoc)
* @see at.spardat.xma.mdl.Descriptive#describe(DNode)
*/
public void describe(DNode node) {
node.sb();
node.app("type", Byte.toString(type)).comma()
.app("value", Long.toString(value)).comma()
.app("saved", Long.toString(saved)).comma()
.app("changed", hasHistory);
node.eb();
}
/**
* Set the current value
* @throws IllegalArgumentException if the new value does not fit into the logical type
*/
public void set(long value) {
switch(type) {
case T_BYTE: if(value>Byte.MAX_VALUE||valueShort.MAX_VALUE||valueInteger.MAX_VALUE||value