org.apache.bookkeeper.client.api.LedgerEntry Maven / Gradle / Ivy
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*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
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* 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.bookkeeper.client.api;
import io.netty.buffer.ByteBuf;
import java.nio.ByteBuffer;
import org.apache.bookkeeper.common.annotation.InterfaceAudience.Public;
import org.apache.bookkeeper.common.annotation.InterfaceStability.Unstable;
/**
* An entry in a ledger.
*
* The entry implementation may hold references to byte buffers under the hood. The users holding the
* references to the instances of this class, are responsible for calling {@link LedgerEntry#close()} to release
* resources held by the entry instances.
*
* @since 4.6
*/
@Public
@Unstable
public interface LedgerEntry extends AutoCloseable {
/**
* The id of the ledger which contains the entry.
*
* @return the id of the ledger
*/
long getLedgerId();
/**
* The id of the entry.
*
* @return the id of the entry
*/
long getEntryId();
/**
* The length of the entry, that is the size of the content expressed in bytes.
*
* @return the size of the content
*/
long getLength();
/**
* Returns the content of the entry as a byte array.
*
* @return the content of the entry
*/
byte[] getEntryBytes();
/**
* Exposes this entry's data as an NIO {@link ByteBuffer}. The returned buffer
* shares the content with this underneath bytebuf (which you can get it by {@link #getEntryBuffer()}).
* Changing the position and limit of the returned NIO buffer does not affect the indexes and
* marks of this underneath buffer. This method is identical
* to {@code entry.getEntryBuffer().nioBuffer()}. This method does not
* modify {@code readerIndex} or {@code writerIndex} of the underlying bytebuf.
*/
ByteBuffer getEntryNioBuffer();
/**
* Return the internal {@link ByteBuf} that contains the entry payload.
*
*
This call doesn't change the reference count on the returned bytebuf. If you want to use the bytebuf
* after the entry is released (via {@link #close()}, the caller must retain the references of the bytebuf.
*
* @return a ByteBuf which contains the data
*/
ByteBuf getEntryBuffer();
/**
* Returns a duplicate of this entry.
*
*
This call will retain a slice of the underneath byte buffer.
*
* @return a duplicated ledger entry
*/
LedgerEntry duplicate();
/**
* {@inheritDoc}
*/
@Override
void close();
}