/*
* 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.hadoop.hbase;
import java.nio.ByteBuffer;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.util.ByteBufferUtils;
import org.apache.hadoop.hbase.util.ByteRange;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.IterableUtils;
import org.apache.hadoop.io.WritableUtils;
/**
* static convenience methods for dealing with KeyValues and collections of KeyValues
*/
@InterfaceAudience.Private
public class KeyValueUtil {
/**************** length *********************/
public static int length(final Cell cell) {
return (int)KeyValue.getKeyValueDataStructureSize(cell.getRowLength(), cell.getFamilyLength(),
cell.getQualifierLength(), cell.getValueLength());
}
protected static int keyLength(final Cell cell) {
return (int)KeyValue.getKeyDataStructureSize(cell.getRowLength(), cell.getFamilyLength(),
cell.getQualifierLength());
}
public static int lengthWithMvccVersion(final KeyValue kv, final boolean includeMvccVersion) {
int length = kv.getLength();
if (includeMvccVersion) {
length += WritableUtils.getVIntSize(kv.getMvccVersion());
}
return length;
}
public static int totalLengthWithMvccVersion(final Iterable<? extends KeyValue> kvs,
final boolean includeMvccVersion) {
int length = 0;
for (KeyValue kv : IterableUtils.nullSafe(kvs)) {
length += lengthWithMvccVersion(kv, includeMvccVersion);
}
return length;
}
/**************** copy key only *********************/
public static KeyValue copyToNewKeyValue(final Cell cell) {
KeyValue kvCell = new KeyValue(copyToNewByteArray(cell));
kvCell.setMvccVersion(cell.getMvccVersion());
return kvCell;
}
public static ByteBuffer copyKeyToNewByteBuffer(final Cell cell) {
byte[] bytes = new byte[keyLength(cell)];
appendKeyToByteArrayWithoutValue(cell, bytes, 0);
ByteBuffer buffer = ByteBuffer.wrap(bytes);
buffer.position(buffer.limit());//make it look as if each field were appended
return buffer;
}
public static byte[] copyToNewByteArray(final Cell cell) {
int v1Length = length(cell);
byte[] backingBytes = new byte[v1Length];
appendToByteArray(cell, backingBytes, 0);
return backingBytes;
}
protected static int appendKeyToByteArrayWithoutValue(final Cell cell, final byte[] output,
final int offset) {
int nextOffset = offset;
nextOffset = Bytes.putShort(output, nextOffset, cell.getRowLength());
nextOffset = CellUtil.copyRowTo(cell, output, nextOffset);
nextOffset = Bytes.putByte(output, nextOffset, cell.getFamilyLength());
nextOffset = CellUtil.copyFamilyTo(cell, output, nextOffset);
nextOffset = CellUtil.copyQualifierTo(cell, output, nextOffset);
nextOffset = Bytes.putLong(output, nextOffset, cell.getTimestamp());
nextOffset = Bytes.putByte(output, nextOffset, cell.getTypeByte());
return nextOffset;
}
/**************** copy key and value *********************/
public static int appendToByteArray(final Cell cell, final byte[] output, final int offset) {
int pos = offset;
pos = Bytes.putInt(output, pos, keyLength(cell));
pos = Bytes.putInt(output, pos, cell.getValueLength());
pos = appendKeyToByteArrayWithoutValue(cell, output, pos);
CellUtil.copyValueTo(cell, output, pos);
return pos + cell.getValueLength();
}
public static ByteBuffer copyToNewByteBuffer(final Cell cell) {
byte[] bytes = new byte[length(cell)];
appendToByteArray(cell, bytes, 0);
ByteBuffer buffer = ByteBuffer.wrap(bytes);
buffer.position(buffer.limit());//make it look as if each field were appended
return buffer;
}
public static void appendToByteBuffer(final ByteBuffer bb, final KeyValue kv,
final boolean includeMvccVersion) {
// keep pushing the limit out. assume enough capacity
bb.limit(bb.position() + kv.getLength());
bb.put(kv.getBuffer(), kv.getOffset(), kv.getLength());
if (includeMvccVersion) {
int numMvccVersionBytes = WritableUtils.getVIntSize(kv.getMvccVersion());
ByteBufferUtils.extendLimit(bb, numMvccVersionBytes);
ByteBufferUtils.writeVLong(bb, kv.getMvccVersion());
}
}
/**************** iterating *******************************/
/**
* Creates a new KeyValue object positioned in the supplied ByteBuffer and sets the ByteBuffer's
* position to the start of the next KeyValue. Does not allocate a new array or copy data.
*/
public static KeyValue nextShallowCopy(final ByteBuffer bb, final boolean includesMvccVersion) {
if (bb.isDirect()) {
throw new IllegalArgumentException("only supports heap buffers");
}
if (bb.remaining() < 1) {
return null;
}
int underlyingArrayOffset = bb.arrayOffset() + bb.position();
int keyLength = bb.getInt();
int valueLength = bb.getInt();
int kvLength = KeyValue.KEYVALUE_INFRASTRUCTURE_SIZE + keyLength + valueLength;
KeyValue keyValue = new KeyValue(bb.array(), underlyingArrayOffset, kvLength);
ByteBufferUtils.skip(bb, keyLength + valueLength);
if (includesMvccVersion) {
long mvccVersion = ByteBufferUtils.readVLong(bb);
keyValue.setMvccVersion(mvccVersion);
}
return keyValue;
}
/*************** next/previous **********************************/
/**
* Append single byte 0x00 to the end of the input row key
*/
public static KeyValue createFirstKeyInNextRow(final Cell in){
byte[] nextRow = new byte[in.getRowLength() + 1];
System.arraycopy(in.getRowArray(), in.getRowOffset(), nextRow, 0, in.getRowLength());
nextRow[nextRow.length - 1] = 0;//maybe not necessary
return KeyValue.createFirstOnRow(nextRow);
}
/**
* Increment the row bytes and clear the other fields
*/
public static KeyValue createFirstKeyInIncrementedRow(final Cell in){
byte[] thisRow = new ByteRange(in.getRowArray(), in.getRowOffset(), in.getRowLength())
.deepCopyToNewArray();
byte[] nextRow = Bytes.unsignedCopyAndIncrement(thisRow);
return KeyValue.createFirstOnRow(nextRow);
}
/**
* Decrement the timestamp. For tests (currently wasteful)
*
* Remember timestamps are sorted reverse chronologically.
* @param in
* @return previous key
*/
public static KeyValue previousKey(final KeyValue in) {
return KeyValue.createFirstOnRow(CellUtil.getRowArray(in), CellUtil.getFamilyArray(in),
CellUtil.getQualifierArray(in), in.getTimestamp() - 1);
}
/*************** misc **********************************/
/**
* @param cell
* @return <code>cell<code> if it is an instance of {@link KeyValue} else we will return a
* new {@link KeyValue} instance made from <code>cell</code>
*/
public static KeyValue ensureKeyValue(final Cell cell) {
if (cell == null) return null;
return cell instanceof KeyValue? (KeyValue)cell: copyToNewKeyValue(cell);
}
}