com.google.protobuf.HBaseZeroCopyByteString 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 com.google.protobuf; // This is a lie.
import org.apache.yetus.audience.InterfaceAudience;
/**
* Helper class to extract byte arrays from {@link ByteString} without copy.
*
* Without this protobufs would force us to copy every single byte array out
* of the objects de-serialized from the wire (which already do one copy, on
* top of the copies the JVM does to go from kernel buffer to C buffer and
* from C buffer to JVM buffer).
*
* @since 0.96.1
*/
@InterfaceAudience.Private
public final class HBaseZeroCopyByteString extends LiteralByteString {
// Gotten from AsyncHBase code base with permission.
/** Private constructor so this class cannot be instantiated. */
private HBaseZeroCopyByteString() {
super(null);
throw new UnsupportedOperationException("Should never be here.");
}
/**
* Wraps a byte array in a {@link ByteString} without copying it.
* @param array array to be wrapped
* @return wrapped array
*/
public static ByteString wrap(final byte[] array) {
return new LiteralByteString(array);
}
/**
* Wraps a subset of a byte array in a {@link ByteString} without copying it.
* @param array array to be wrapped
* @param offset from
* @param length length
* @return wrapped array
*/
public static ByteString wrap(final byte[] array, int offset, int length) {
return new BoundedByteString(array, offset, length);
}
// TODO:
// ZeroCopyLiteralByteString.wrap(this.buf, 0, this.count);
/**
* Extracts the byte array from the given {@link ByteString} without copy.
* @param buf A buffer from which to extract the array. This buffer must be
* actually an instance of a {@code LiteralByteString}.
* @return byte[] representation
*/
public static byte[] zeroCopyGetBytes(final ByteString buf) {
if (buf instanceof LiteralByteString) {
return ((LiteralByteString) buf).bytes;
}
throw new UnsupportedOperationException("Need a LiteralByteString, got a "
+ buf.getClass().getName());
}
}