cassandra-trunk/src/java/org/apache/cassandra/exceptions/UnavailableException.java
/*
 * 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.cassandra.exceptions;

import org.apache.cassandra.db.ConsistencyLevel;

public class UnavailableException extends RequestExecutionException
{
    public final ConsistencyLevel consistency;
    public final int required;
    public final int alive;

    public static UnavailableException create(ConsistencyLevel consistency, int required, int alive)
    {
        assert alive < required;
        return create(consistency, required, 0, alive, 0);
    }

    public static UnavailableException create(ConsistencyLevel consistency, int required, int requiredFull, int alive, int aliveFull)
    {
        if (required > alive)
            return new UnavailableException("Cannot achieve consistency level " + consistency, consistency, required, alive);
        assert requiredFull < aliveFull;
        return new UnavailableException("Insufficient full replicas", consistency, required, alive);
    }

    public static UnavailableException create(ConsistencyLevel consistency, String dc, int required, int requiredFull, int alive, int aliveFull)
    {
        if (required > alive)
            return new UnavailableException("Cannot achieve consistency level " + consistency + " in DC " + dc, consistency, required, alive);
        assert requiredFull < aliveFull;
        return new UnavailableException("Insufficient full replicas in DC " + dc, consistency, required, alive);
    }

    public UnavailableException(String msg, ConsistencyLevel consistency, int required, int alive)
    {
        super(ExceptionCode.UNAVAILABLE, msg);
        this.consistency = consistency;
        this.required = required;
        this.alive = alive;
    }
}
