/*
* Copyright 2013-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.util;
/**
* A Base 32 codec implementation.
*
* @author Hanson Char
*/
class Base32Codec extends AbstractBase32Codec {
private static final int OFFSET_OF_2 = '2' - 26;
private static class LazyHolder {
private static final byte[] DECODED = decodeTable();
private static byte[] decodeTable() {
final byte[] dest = new byte['z' + 1];
for (int i = 0; i <= 'z'; i++)
{
if (i >= 'A' && i <= 'Z')
dest[i] = (byte) (i - 'A');
else if (i >= '2' && i <= '7')
dest[i] = (byte) (i - OFFSET_OF_2);
else if (i >= 'a' && i <= 'z')
dest[i] = (byte) (i - 'a');
else
dest[i] = -1;
}
return dest;
}
}
private static byte[] alphabets() {
// Base 32 alphabet as defined at http://www.ietf.org/rfc/rfc4648.txt
return CodecUtils.toBytesDirect("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567");
}
Base32Codec() {
super(alphabets());
}
@Override
protected int pos(byte in) {
int pos = LazyHolder.DECODED[in];
if (pos > -1)
return pos;
throw new IllegalArgumentException("Invalid base 32 character: \'" + (char) in + "\'");
}
}