| /* |
| * 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.accumulo.core.client.lexicoder; |
| |
| import org.apache.accumulo.core.client.lexicoder.impl.AbstractLexicoder; |
| |
| /** |
| * Unsigned long lexicoder. The lexicographic encoding sorts first 0l and -1l last. This encoding |
| * does not correspond to the sort of Long because it does not consider the sign bit. If Java had an |
| * unsigned long type, this encoder would correspond to its sort order. |
| * |
| * @since 1.6.0 |
| */ |
| public class ULongLexicoder extends AbstractLexicoder<Long> { |
| |
| @Override |
| public byte[] encode(Long l) { |
| int shift = 56; |
| int index; |
| int prefix = l < 0 ? 0xff : 0x00; |
| |
| for (index = 0; index < 8; index++) { |
| if (((l >>> shift) & 0xff) != prefix) |
| break; |
| |
| shift -= 8; |
| } |
| |
| byte ret[] = new byte[9 - index]; |
| ret[0] = (byte) (8 - index); |
| for (index = 1; index < ret.length; index++) { |
| ret[index] = (byte) (l >>> shift); |
| shift -= 8; |
| } |
| |
| if (l < 0) |
| ret[0] = (byte) (16 - ret[0]); |
| |
| return ret; |
| |
| } |
| |
| @Override |
| protected Long decodeUnchecked(byte[] data, int offset, int len) { |
| |
| long l = 0; |
| int shift = 0; |
| |
| if (data[offset] < 0 || data[offset] > 16) |
| throw new IllegalArgumentException("Unexpected length " + (0xff & data[offset])); |
| |
| for (int i = (offset + len) - 1; i >= offset + 1; i--) { |
| l += (data[i] & 0xffL) << shift; |
| shift += 8; |
| } |
| |
| // fill in 0xff prefix |
| if (data[offset] > 8) |
| l |= -1L << ((16 - data[offset]) << 3); |
| |
| return l; |
| } |
| |
| @Override |
| public Long decode(byte[] b) { |
| // This concrete implementation is provided for binary compatibility with 1.6; it can be removed |
| // in 2.0. See ACCUMULO-3789. |
| return super.decode(b); |
| } |
| } |