org.apache.bookkeeper.bookie.EntryKeyValue Maven / Gradle / Ivy
/**
* Copyright The Apache Software Foundation
*
* 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.bookie;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import java.nio.ByteBuffer;
/**
* An entry Key/Value.
* EntryKeyValue wraps a byte array and takes offsets and lengths into the array to
* interpret the content as entry blob.
*/
public class EntryKeyValue extends EntryKey {
private final byte [] bytes;
private int offset = 0; // start offset of entry blob
private int length = 0; // length of entry blob
/**
* @return The byte array backing this EntryKeyValue.
*/
public byte [] getBuffer() {
return this.bytes;
}
/**
* @return Offset into {@link #getBuffer()} at which the EntryKeyValue starts.
*/
public int getOffset() {
return this.offset;
}
/**
* @return Length of bytes this EntryKeyValue occupies in {@link #getBuffer()}.
*/
public int getLength() {
return this.length;
}
/**
* Creates a EntryKeyValue from the start of the specified byte array.
* Presumes bytes content contains the value portion of a EntryKeyValue.
* @param bytes byte array
*/
public EntryKeyValue(long ledgerId, long entryId, final byte [] bytes) {
this(ledgerId, entryId, bytes, 0, bytes.length);
}
/**
* Creates a EntryKeyValue from the start of the specified byte array.
* Presumes bytes content contains the value portion of a EntryKeyValue.
* @param bytes byte array
* @param offset offset in bytes as start of blob
* @param length of blob
*/
public EntryKeyValue(long ledgerId, long entryId, final byte [] bytes, int offset, int length) {
super(ledgerId, entryId);
this.bytes = bytes;
this.offset = offset;
this.length = length;
}
/**
* Returns the blob wrapped in a new ByteBuffer.
*
* @return the value
*/
public ByteBuf getValueAsByteBuffer() {
return Unpooled.wrappedBuffer(getBuffer(), getOffset(), getLength());
}
/**
* Write EntryKeyValue blob into the provided byte buffer.
*
* @param dst the bytes buffer to use
*
* @return The number of useful bytes in the buffer.
*
* @throws IllegalArgumentException an illegal value was passed or there is insufficient space
* remaining in the buffer
*/
int writeToByteBuffer(ByteBuffer dst) {
if (dst.remaining() < getLength()) {
throw new IllegalArgumentException("Buffer size " + dst.remaining() + " < " + getLength());
}
dst.put(getBuffer(), getOffset(), getLength());
return getLength();
}
/**
* String representation.
*/
@Override
public String toString() {
return ledgerId + ":" + entryId;
}
@Override
public boolean equals(Object other) {
// since this entry is identified by (lid, eid)
// so just use {@link org.apache.bookkeeper.bookie.EntryKey#equals}.
return super.equals(other);
}
@Override
public int hashCode() {
// since this entry is identified by (lid, eid)
// so just use {@link org.apache.bookkeeper.bookie.EntryKey#hashCode} as the hash code.
return super.hashCode();
}
}