| /* |
| * 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.pregelix.api.graph; |
| |
| /** |
| * Users can extend this interface to speedup the performance, e.g., the Alpha-sort optimization for cache locality. |
| * The normalized key is an unsigned integer (represented by a signed integer, though) obtained from the binary represetnation |
| * of the corresponding vertex id. |
| * Usually the normalized key can be obtained from the prefix bytes of the vertex id bytes. |
| * |
| * @author yingyib |
| */ |
| public interface NormalizedKeyComputer { |
| |
| /** |
| * Get the normalized key from the byte region of a vertex id. |
| * The following three parameters represent the byte region of a vertex id. |
| * |
| * @param data |
| * @param start |
| * @param len |
| * @return the normalized key. |
| */ |
| public int getNormalizedKey(byte[] data, int start, int len); |
| } |