1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18 package org.apache.hadoop.hbase.util;
19
20 import org.apache.commons.logging.Log;
21 import org.apache.commons.logging.LogFactory;
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23
24 import com.google.protobuf.ByteString;
25 import com.google.protobuf.HBaseZeroCopyByteString;
26
27 /**
28 * Hack to workaround HBASE-1304 issue that keeps bubbling up when a mapreduce context.
29 */
30 @InterfaceAudience.Private
31 public class ByteStringer {
32 private static final Log LOG = LogFactory.getLog(ByteStringer.class);
33
34 /**
35 * Flag set at class loading time.
36 */
37 private static boolean USE_ZEROCOPYBYTESTRING = true;
38
39 // Can I classload HBaseZeroCopyByteString without IllegalAccessError?
40 // If we can, use it passing ByteStrings to pb else use native ByteString though more costly
41 // because it makes a copy of the passed in array.
42 static {
43 try {
44 HBaseZeroCopyByteString.wrap(new byte [0]);
45 } catch (IllegalAccessError iae) {
46 USE_ZEROCOPYBYTESTRING = false;
47 LOG.debug("Failed to classload HBaseZeroCopyByteString: " + iae.toString());
48 }
49 }
50
51 private ByteStringer() {
52 super();
53 }
54
55 /**
56 * Wraps a byte array in a {@link ByteString} without copying it.
57 */
58 public static ByteString wrap(final byte[] array) {
59 return USE_ZEROCOPYBYTESTRING? HBaseZeroCopyByteString.wrap(array): ByteString.copyFrom(array);
60 }
61
62 /**
63 * Wraps a subset of a byte array in a {@link ByteString} without copying it.
64 */
65 public static ByteString wrap(final byte[] array, int offset, int length) {
66 return USE_ZEROCOPYBYTESTRING? HBaseZeroCopyByteString.wrap(array, offset, length):
67 ByteString.copyFrom(array, offset, length);
68 }
69 }