/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jackrabbit.jcr2spi.state;
/**
* <code>Status</code>...
*/
public final class Status {
/**
* Avoid instantiation
*/
private Status() {}
public static final int _UNDEFINED_ = -1;
/**
* A state once read from persistent storage has been set to invalid. This
* means that the state needs to be re-fetched from persistent storage when
* accessed the next time.
*/
public static final int INVALIDATED = 0;
/**
* 'existing', i.e. persistent state
*/
public static final int EXISTING = 1;
/**
* 'existing', i.e. persistent state that has been transiently modified (copy-on-write)
*/
public static final int EXISTING_MODIFIED = 2;
/**
* 'existing', i.e. persistent state that has been transiently removed (copy-on-write)
*/
public static final int EXISTING_REMOVED = 3;
/**
* 'new' state
*/
public static final int NEW = 4;
/**
* 'existing', i.e. persistent state that has been persistently modified by somebody else
*/
public static final int STALE_MODIFIED = 5;
/**
* 'existing', i.e. persistent state that has been destroyed by somebody else
*/
public static final int STALE_DESTROYED = 6;
/**
* Temporary status used to mark a state, this is permanently modified
* either by saving transient changes, by workspace operations or by
* external modification.
*/
public static final int MODIFIED = 7;
/**
* a new state was removed and is now 'removed'
* or an existing item has been removed by a workspace operation or
* by an external modification.
*/
public static final int REMOVED = 8;
private static final String[] STATUS_NAMES = new String[] {
"INVALIDATED",
"EXISTING",
"EXISTING_MODIFIED",
"EXISTING_REMOVED",
"NEW",
"STALE_MODIFIED",
"STALE_DESTROYED",
"MODIFIED",
"REMOVED"
};
/**
* Returns <code>true</code> if the given status is a terminal status, i.e.
* the given status one of:
* <ul>
* <li>{@link #REMOVED}</li>
* <li>{@link #STALE_DESTROYED}</li>
* </ul>
*
* @param status
* @return true if the given status is terminal.
*/
public static boolean isTerminal(int status) {
return status == REMOVED || status == STALE_DESTROYED;
}
/**
* Returns <code>true</code> if this item state is valid, that is its status
* is one of:
* <ul>
* <li>{@link #EXISTING}</li>
* <li>{@link #EXISTING_MODIFIED}</li>
* <li>{@link #NEW}</li>
* </ul>
*
* @param status
* @return true if the given status indicates a valid ItemState.
*/
public static boolean isValid(int status) {
return status == EXISTING || status == EXISTING_MODIFIED || status == NEW;
}
/**
* Returns <code>true</code> if <code>status</code> is one of:
* <ul>
* <li>{@link #STALE_DESTROYED}</li>
* <li>{@link #STALE_MODIFIED}</li>
* </ul>
*
* @param status the status to check.
* @return <code>true</code> if <code>status</code> indicates that an item
* state is stale.
*/
public static boolean isStale(int status) {
return status == STALE_DESTROYED || status == STALE_MODIFIED;
}
/**
* Returns <code>true</code> if <code>status</code> is one of:
* <ul>
* <li>{@link #EXISTING_MODIFIED}</li>
* <li>{@link #EXISTING_REMOVED}</li>
* <li>{@link #NEW}</li>
* </ul>
*
* @param status the status to check.
* @return <code>true</code> if <code>status</code> indicates that an item
* state is transiently modified.
*/
public static boolean isTransient(int status) {
return status == EXISTING_MODIFIED || status == EXISTING_REMOVED || status == NEW;
}
/**
* Returns true, if the status of an item state can be changed from
* <code>oldStatus</code> to <code>newStatus</code>, and false if the
* change is illegal or if any of the given status flags is illegal.
*
* @param oldStatus
* @param newStatus
* @return true if a status change from <code>oldStatus</code> to
* <code>newStatus</code> is allowed or if the two status are the same.
*/
public static boolean isValidStatusChange(int oldStatus, int newStatus) {
if (oldStatus == newStatus) {
return true;
}
boolean isValid = false;
// valid status changes for session-states
switch (newStatus) {
case INVALIDATED:
isValid = (oldStatus == EXISTING); // invalidate
break;
case EXISTING:
switch (oldStatus) {
case INVALIDATED: /* refresh */
case NEW: /* save */
case EXISTING_MODIFIED: /* save, revert */
case EXISTING_REMOVED: /* revert */
case STALE_MODIFIED: /* revert */
case MODIFIED:
isValid = true;
break;
/* REMOVED, STALE_DESTROYED -> false */
}
break;
case EXISTING_MODIFIED:
isValid = (oldStatus == EXISTING);
break;
case EXISTING_REMOVED:
isValid = (oldStatus == EXISTING || oldStatus == EXISTING_MODIFIED);
break;
case STALE_MODIFIED:
case STALE_DESTROYED:
isValid = (oldStatus == EXISTING_MODIFIED || oldStatus == EXISTING_REMOVED || oldStatus == STALE_MODIFIED);
break;
case REMOVED:
// removal always possible -> getNewStatus(int, int)
isValid = true;
break;
case MODIFIED:
// except for NEW states an external modification is always valid
if (oldStatus != NEW) {
isValid = true;
}
break;
/* default:
NEW cannot change state to NEW -> false */
}
return isValid;
}
/**
* Returns the given <code>newStatusHint</code> unless the new status
* collides with a pending modification or removal which results in a
* stale item state.
*
* @param oldStatus
* @param newStatusHint
* @return new status that takes transient modification/removal into account.
*/
public static int getNewStatus(int oldStatus, int newStatusHint) {
int newStatus;
switch (newStatusHint) {
case Status.MODIFIED:
// underlying state has been modified by external changes
if (oldStatus == Status.EXISTING || oldStatus == Status.INVALIDATED) {
// temporarily set the state to MODIFIED in order to inform listeners.
newStatus = Status.MODIFIED;
} else if (oldStatus == Status.EXISTING_MODIFIED) {
newStatus = Status.STALE_MODIFIED;
} else {
// old status is EXISTING_REMOVED (or any other) => ignore.
// a NEW state may never be marked modified.
newStatus = oldStatus;
}
break;
case Status.REMOVED:
if (oldStatus == Status.EXISTING_MODIFIED || oldStatus == Status.STALE_MODIFIED) {
newStatus = Status.STALE_DESTROYED;
} else {
// applies both to NEW or to any other status
newStatus = newStatusHint;
}
break;
default:
newStatus = newStatusHint;
break;
}
return newStatus;
}
/**
* @param status A valid status constant.
* @return Human readable status name for the given int.
*/
public static String getName(int status) {
if (status == _UNDEFINED_) {
return "_UNDEFINED_";
}
if (status < 0 || status >= STATUS_NAMES.length) {
throw new IllegalArgumentException("Invalid status " + status);
}
return STATUS_NAMES[status];
}
}