org.apache.bookkeeper.mledger.offload.jcloud.DataBlockHeader Maven / Gradle / Ivy
/**
* 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.bookkeeper.mledger.offload.jcloud;
import java.io.InputStream;
import org.apache.bookkeeper.common.annotation.InterfaceStability.Unstable;
/**
* The data block header in tiered storage for each data block.
*
* Currently, It is in format:
* [ magic_word -- int ][ block_len -- int ][ first_entry_id -- long][padding]
*
* with the size: 4 + 4 + 8 + padding = 128 Bytes
*/
@Unstable
public interface DataBlockHeader {
/**
* Get the length of the block in bytes, including the header.
*/
long getBlockLength();
/**
* Get the message entry Id for the first message that stored in this data block.
*/
long getFirstEntryId();
/**
* Get the size of this DataBlockHeader.
*/
long getHeaderLength();
/**
* Get the content of the data block header as InputStream.
* Read out in current format.
*/
InputStream toStream();
}