/*
 * 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.usergrid.persistence.collection.mvcc.entity;


/**
 * The different stages that can exist in the commit log
 */
public enum Stage {

    /**
     * These are bitmasks that represent the state's we've been through
     *
     * Active => 0000
     * RollBack => 1000
     * COMMITTED => 1100
     * POSTPROCESSOR => 1110
     * ACTIVE => 1111
     */

    /**
     * The entity has started writing but is not yet committed
     */
    ACTIVE( true, 0 ),

    /**
     * The entity has started writing but not yet committed.
     */
    ROLLBACK( true, 1 ),
    /**
     * We have applied enough writes to be able to recover via writeahead logging.  The system can recover from a crash
     * without data loss at this point
     */
    COMMITTED( false, 2 ),
    /**
     * The entity is going through post processing
     */
    POSTPROCESS( false, 6 ),

    /**
     * The entity has completed all post processing
     */
    COMPLETE( false, 14 );


    private final boolean transientStage;
    private final int id;


    private Stage( final boolean transientStage, final int id ) {
        this.transientStage = transientStage;
        this.id = id;
    }


    /**
     * Returns true if this stage is transient and should not be retained in the datastore permanently Stages such as
     * start and write don't need to be retained, but can be used to signal "in flight" updates
     */
    public boolean isTransient() {
        return transientStage;
    }


    public int getId() {
        return this.id;
    }

}