| /* |
| * Copyright 2009-2013 by The Regents of the University of California |
| * Licensed 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 from |
| * |
| * 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 edu.uci.ics.hivesterix.runtime.factory.hashfunction;
|
|
|
| import edu.uci.ics.hivesterix.serde.lazy.LazyUtils;
|
| import edu.uci.ics.hivesterix.serde.lazy.LazyUtils.VInt;
|
| import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunction;
|
| import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunctionFactory;
|
|
|
| public class HiveStingBinaryHashFunctionFactory implements IBinaryHashFunctionFactory {
|
| private static final long serialVersionUID = 1L;
|
|
|
| public static HiveStingBinaryHashFunctionFactory INSTANCE = new HiveStingBinaryHashFunctionFactory();
|
|
|
| private HiveStingBinaryHashFunctionFactory() {
|
| }
|
|
|
| @Override
|
| public IBinaryHashFunction createBinaryHashFunction() {
|
| // TODO Auto-generated method stub
|
| return new IBinaryHashFunction() {
|
| private VInt len = new VInt();
|
|
|
| @Override
|
| public int hash(byte[] bytes, int offset, int length) {
|
| LazyUtils.readVInt(bytes, offset, len);
|
| if (len.value + len.length != length)
|
| throw new IllegalStateException("parse string: length mismatch, expected "
|
| + (len.value + len.length) + " but get " + length);
|
| return hashBytes(bytes, offset + len.length, length - len.length);
|
| }
|
|
|
| public int hashBytes(byte[] bytes, int offset, int length) {
|
| int value = 1;
|
| int end = offset + length;
|
| for (int i = offset; i < end; i++)
|
| value = value * 31 + (int) bytes[i];
|
| return value;
|
| }
|
| };
|
| }
|
|
|
| }
|