BookieProtocol.java

package org.apache.bookkeeper.proto;

/*
 * 
 * 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.
 * 
 */

/**
 * The packets of the Bookie protocol all have a 4-byte integer indicating the
 * type of request or response at the very beginning of the packet followed by a
 * payload.
 * 
 */
public interface BookieProtocol {
    /**
     * The Add entry request payload will be a ledger entry exactly as it should
     * be logged. The response payload will be a 4-byte integer that has the
     * error code followed by the 8-byte ledger number and 8-byte entry number
     * of the entry written.
     */
    public static final int ADDENTRY = 1;
    /**
     * The Read entry request payload will be the ledger number and entry number
     * to read. (The ledger number is an 8-byte integer and the entry number is
     * a 8-byte integer.) The response payload will be a 4-byte integer
     * representing an error code and a ledger entry if the error code is EOK,
     * otherwise it will be the 8-byte ledger number and the 4-byte entry number
     * requested. (Note that the first sixteen bytes of the entry happen to be
     * the ledger number and entry number as well.)
     */
    public static final int READENTRY = 2;

    /**
     * The error code that indicates success
     */
    public static final int EOK = 0;
    /**
     * The error code that indicates that the ledger does not exist
     */
    public static final int ENOLEDGER = 1;
    /**
     * The error code that indicates that the requested entry does not exist
     */
    public static final int ENOENTRY = 2;
    /**
     * The error code that indicates an invalid request type
     */
    public static final int EBADREQ = 100;
    /**
     * General error occurred at the server
     */
    public static final int EIO = 101;

    /**
     * Unauthorized access to ledger
     */
    public static final int EUA = 102;

}