org.apache.hudi.org.apache.hadoop.hbase.Tag 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.hadoop.hbase;
import java.nio.ByteBuffer;
import org.apache.hadoop.hbase.util.ByteBufferUtils;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
/**
* Tags are part of cells and helps to add metadata about them.
* Metadata could be ACLs, visibility labels, etc.
*
* Each Tag is having a type (one byte) and value part. The max value length for a Tag is 65533.
*
* See {@link TagType} for reserved tag types.
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface Tag {
public final static int TYPE_LENGTH_SIZE = Bytes.SIZEOF_BYTE;
public final static int TAG_LENGTH_SIZE = Bytes.SIZEOF_SHORT;
public final static int INFRASTRUCTURE_SIZE = TYPE_LENGTH_SIZE + TAG_LENGTH_SIZE;
public static final int MAX_TAG_LENGTH = (2 * Short.MAX_VALUE) + 1 - TAG_LENGTH_SIZE;
/**
* Custom tags if created are suggested to be above this range. So that
* it does not overlap with internal tag types
*/
public static final byte CUSTOM_TAG_TYPE_RANGE = (byte)64;
/**
* @return the tag type
*/
byte getType();
/**
* @return Offset of tag value within the backed buffer
*/
int getValueOffset();
/**
* @return Length of tag value within the backed buffer
*/
int getValueLength();
/**
* Tells whether or not this Tag is backed by a byte array.
* @return true when this Tag is backed by byte array
*/
boolean hasArray();
/**
* @return The array containing the value bytes.
* @throws UnsupportedOperationException
* when {@link #hasArray()} return false. Use {@link #getValueByteBuffer()} in such
* situation
*/
byte[] getValueArray();
/**
* @return The {@link java.nio.ByteBuffer} containing the value bytes.
*/
ByteBuffer getValueByteBuffer();
/**
* Returns tag value in a new byte array. Primarily for use client-side. If server-side, use
* {@link Tag#getValueArray()} with appropriate {@link Tag#getValueOffset()} and
* {@link Tag#getValueLength()} instead to save on allocations.
* @param tag The Tag whose value to be returned
* @return tag value in a new byte array.
*/
public static byte[] cloneValue(Tag tag) {
int tagLength = tag.getValueLength();
byte[] tagArr = new byte[tagLength];
if (tag.hasArray()) {
Bytes.putBytes(tagArr, 0, tag.getValueArray(), tag.getValueOffset(), tagLength);
} else {
ByteBufferUtils.copyFromBufferToArray(tagArr, tag.getValueByteBuffer(), tag.getValueOffset(),
0, tagLength);
}
return tagArr;
}
/**
* Converts the value bytes of the given tag into a String value
* @param tag The Tag
* @return value as String
*/
public static String getValueAsString(Tag tag) {
if (tag.hasArray()) {
return Bytes.toString(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
}
return Bytes.toString(cloneValue(tag));
}
/**
* Matches the value part of given tags
* @param t1 Tag to match the value
* @param t2 Tag to match the value
* @return True if values of both tags are same.
*/
public static boolean matchingValue(Tag t1, Tag t2) {
if (t1.hasArray() && t2.hasArray()) {
return Bytes.equals(t1.getValueArray(), t1.getValueOffset(), t1.getValueLength(),
t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
}
if (t1.hasArray()) {
return ByteBufferUtils.equals(t2.getValueByteBuffer(), t2.getValueOffset(),
t2.getValueLength(), t1.getValueArray(), t1.getValueOffset(), t1.getValueLength());
}
if (t2.hasArray()) {
return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(),
t1.getValueLength(), t2.getValueArray(), t2.getValueOffset(), t2.getValueLength());
}
return ByteBufferUtils.equals(t1.getValueByteBuffer(), t1.getValueOffset(), t1.getValueLength(),
t2.getValueByteBuffer(), t2.getValueOffset(), t2.getValueLength());
}
/**
* Copies the tag's value bytes to the given byte array
* @param tag The Tag
* @param out The byte array where to copy the Tag value.
* @param offset The offset within 'out' array where to copy the Tag value.
*/
public static void copyValueTo(Tag tag, byte[] out, int offset) {
if (tag.hasArray()) {
Bytes.putBytes(out, offset, tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
} else {
ByteBufferUtils.copyFromBufferToArray(out, tag.getValueByteBuffer(), tag.getValueOffset(),
offset, tag.getValueLength());
}
}
/**
* Converts the value bytes of the given tag into a long value
* @param tag The Tag
* @return value as long
*/
public static long getValueAsLong(Tag tag) {
if (tag.hasArray()) {
return Bytes.toLong(tag.getValueArray(), tag.getValueOffset(), tag.getValueLength());
}
return ByteBufferUtils.toLong(tag.getValueByteBuffer(), tag.getValueOffset());
}
/**
* Converts the value bytes of the given tag into a byte value
* @param tag The Tag
* @return value as byte
*/
public static byte getValueAsByte(Tag tag) {
if (tag.hasArray()) {
return tag.getValueArray()[tag.getValueOffset()];
}
return ByteBufferUtils.toByte(tag.getValueByteBuffer(), tag.getValueOffset());
}
}