| /* |
| * 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.commons.compress.archivers.cpio; |
| |
| /** |
| * Package private utility class for Cpio |
| * |
| * @Immutable |
| */ |
| class CpioUtil { |
| /** |
| * Converts a byte array to a long. Halfwords can be swapped by setting |
| * swapHalfWord=true. |
| * |
| * @param number |
| * An array of bytes containing a number |
| * @param swapHalfWord |
| * Swap halfwords ([0][1][2][3]->[1][0][3][2]) |
| * @return The long value |
| * @throws UnsupportedOperationException if number length is not a multiple of 2 |
| */ |
| static long byteArray2long(final byte[] number, final boolean swapHalfWord) { |
| if (number.length % 2 != 0) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| long ret = 0; |
| int pos = 0; |
| byte tmp_number[] = new byte[number.length]; |
| System.arraycopy(number, 0, tmp_number, 0, number.length); |
| |
| if (!swapHalfWord) { |
| byte tmp = 0; |
| for (pos = 0; pos < tmp_number.length; pos++) { |
| tmp = tmp_number[pos]; |
| tmp_number[pos++] = tmp_number[pos]; |
| tmp_number[pos] = tmp; |
| } |
| } |
| |
| ret = tmp_number[0] & 0xFF; |
| for (pos = 1; pos < tmp_number.length; pos++) { |
| ret <<= 8; |
| ret |= tmp_number[pos] & 0xFF; |
| } |
| return ret; |
| } |
| |
| /** |
| * Converts a long number to a byte array |
| * Halfwords can be swapped by setting swapHalfWord=true. |
| * |
| * @param number |
| * the input long number to be converted |
| * |
| * @param length |
| * The length of the returned array |
| * @param swapHalfWord |
| * Swap halfwords ([0][1][2][3]->[1][0][3][2]) |
| * @return The long value |
| * @throws UnsupportedOperationException if the length is not a positive multiple of two |
| */ |
| static byte[] long2byteArray(final long number, final int length, |
| final boolean swapHalfWord) { |
| byte[] ret = new byte[length]; |
| int pos = 0; |
| long tmp_number = 0; |
| |
| if (length % 2 != 0 || length < 2) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| tmp_number = number; |
| for (pos = length - 1; pos >= 0; pos--) { |
| ret[pos] = (byte) (tmp_number & 0xFF); |
| tmp_number >>= 8; |
| } |
| |
| if (!swapHalfWord) { |
| byte tmp = 0; |
| for (pos = 0; pos < length; pos++) { |
| tmp = ret[pos]; |
| ret[pos++] = ret[pos]; |
| ret[pos] = tmp; |
| } |
| } |
| |
| return ret; |
| } |
| } |