org.apache.hadoop.hbase.protobuf.ProtobufMagic 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.hadoop.hbase.protobuf;
import org.apache.yetus.audience.InterfaceAudience;
/**
* Protobufs utility.
*/
@InterfaceAudience.Private
public class ProtobufMagic {
private ProtobufMagic() {
}
/**
* Magic we put ahead of a serialized protobuf message. For example, all znode content is protobuf
* messages with the below magic for preamble.
*/
public static final byte[] PB_MAGIC = new byte[] { 'P', 'B', 'U', 'F' };
/**
* Returns True if passed bytes has {@link #PB_MAGIC} for a prefix.
*/
public static boolean isPBMagicPrefix(final byte[] bytes) {
if (bytes == null) return false;
return isPBMagicPrefix(bytes, 0, bytes.length);
}
/*
* Copied from Bytes.java to here hbase-common now depends on hbase-protocol Referencing
* Bytes.java directly would create circular dependency
*/
private static int compareTo(byte[] buffer1, int offset1, int length1, byte[] buffer2,
int offset2, int length2) {
// Short circuit equal case
if (buffer1 == buffer2 && offset1 == offset2 && length1 == length2) {
return 0;
}
// Bring WritableComparator code local
int end1 = offset1 + length1;
int end2 = offset2 + length2;
for (int i = offset1, j = offset2; i < end1 && j < end2; i++, j++) {
int a = (buffer1[i] & 0xff);
int b = (buffer2[j] & 0xff);
if (a != b) {
return a - b;
}
}
return length1 - length2;
}
/** Returns True if passed bytes has {@link #PB_MAGIC} for a prefix. */
public static boolean isPBMagicPrefix(final byte[] bytes, int offset, int len) {
if (bytes == null || len < PB_MAGIC.length) return false;
return compareTo(PB_MAGIC, 0, PB_MAGIC.length, bytes, offset, PB_MAGIC.length) == 0;
}
/** Returns Length of {@link #PB_MAGIC} */
public static int lengthOfPBMagic() {
return PB_MAGIC.length;
}
}