/*
* Copyright 2015 Odnoklassniki Ltd, Mail.Ru Group
*
* 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 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 one.nio.util;
public final class Base64 {
public static final byte[] DEFAULT_TABLE = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};
public static final byte[] URL_TABLE = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_'
};
private static final byte[] DECODE_TABLE = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 62, 0, 62, 0, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 0, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 0, 0, 0, 0, 63,
0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51
};
public static byte[] encode(byte[] s) {
byte[] result = new byte[(s.length + 2) / 3 << 2];
encode(s, result, 0, DEFAULT_TABLE);
return result;
}
public static byte[] encodeUrl(byte[] s) {
byte[] result = new byte[((s.length << 2) + 2) / 3];
encode(s, result, 0, URL_TABLE);
return result;
}
public static void encode(byte[] s, byte[] result, int p, byte[] table) {
final int len = s.length / 3 * 3;
for (int i = 0; i < len; i += 3, p += 4) {
int v = (s[i] & 0xff) << 16 | (s[i + 1] & 0xff) << 8 | (s[i + 2] & 0xff);
result[p] = table[v >>> 18];
result[p + 1] = table[(v >>> 12) & 0x3f];
result[p + 2] = table[(v >>> 6) & 63];
result[p + 3] = table[v & 0x3f];
}
switch (s.length - len) {
case 1:
result[p] = table[(s[len] & 0xff) >> 2];
result[p + 1] = table[(s[len] & 0x03) << 4];
if (p + 3 < result.length) {
result[p + 2] = '=';
result[p + 3] = '=';
}
break;
case 2:
result[p] = table[(s[len] & 0xff) >> 2];
result[p + 1] = table[(s[len] & 0x03) << 4 | (s[len + 1] & 0xff) >> 4];
result[p + 2] = table[(s[len + 1] & 0x0f) << 2];
if (p + 3 < result.length) {
result[p + 3] = '=';
}
break;
}
}
public static char[] encodeToChars(byte[] s) {
char[] result = new char[(s.length + 2) / 3 << 2];
encodeToChars(s, result, 0, DEFAULT_TABLE);
return result;
}
public static char[] encodeUrlToChars(byte[] s) {
char[] result = new char[((s.length << 2) + 2) / 3];
encodeToChars(s, result, 0, URL_TABLE);
return result;
}
public static void encodeToChars(byte[] s, char[] result, int p, byte[] table) {
final int len = s.length / 3 * 3;
for (int i = 0; i < len; i += 3, p += 4) {
int v = (s[i] & 0xff) << 16 | (s[i + 1] & 0xff) << 8 | (s[i + 2] & 0xff);
result[p] = (char) table[v >>> 18];
result[p + 1] = (char) table[(v >>> 12) & 0x3f];
result[p + 2] = (char) table[(v >>> 6) & 63];
result[p + 3] = (char) table[v & 0x3f];
}
switch (s.length - len) {
case 1:
result[p] = (char) table[(s[len] & 0xff) >> 2];
result[p + 1] = (char) table[(s[len] & 0x03) << 4];
if (p + 3 < result.length) {
result[p + 2] = '=';
result[p + 3] = '=';
}
break;
case 2:
result[p] = (char) table[(s[len] & 0xff) >> 2];
result[p + 1] = (char) table[(s[len] & 0x03) << 4 | (s[len + 1] & 0xff) >> 4];
result[p + 2] = (char) table[(s[len + 1] & 0x0f) << 2];
if (p + 3 < result.length) {
result[p + 3] = '=';
}
break;
}
}
public static byte[] decode(byte[] s) {
int len = s.length;
while (len > 0 && s[len - 1] == '=') {
len--;
}
final int full = (len >> 2) * 3;
final int pad = (len & 3) * 3 >> 2;
final byte[] result = new byte[full + pad];
final byte[] table = DECODE_TABLE;
int i = 0;
for (int p = 0; p < full; p += 3, i += 4) {
int v = table[s[i]] << 18 | table[s[i + 1]] << 12 | table[s[i + 2]] << 6 | table[s[i + 3]];
result[p] = (byte) (v >>> 16);
result[p + 1] = (byte) (v >>> 8);
result[p + 2] = (byte) v;
}
switch (pad) {
case 2:
result[full + 1] = (byte) (table[s[i + 1]] << 4 | table[s[i + 2]] >> 2);
case 1:
result[full] = (byte) (table[s[i]] << 2 | table[s[i + 1]] >> 4);
}
return result;
}
public static byte[] decodeFromChars(char[] s) {
int len = s.length;
while (len > 0 && s[len - 1] == '=') {
len--;
}
final int full = (len >> 2) * 3;
final int pad = (len & 3) * 3 >> 2;
final byte[] result = new byte[full + pad];
final byte[] table = DECODE_TABLE;
int i = 0;
for (int p = 0; p < full; p += 3, i += 4) {
int v = table[s[i]] << 18 | table[s[i + 1]] << 12 | table[s[i + 2]] << 6 | table[s[i + 3]];
result[p] = (byte) (v >>> 16);
result[p + 1] = (byte) (v >>> 8);
result[p + 2] = (byte) v;
}
switch (pad) {
case 2:
result[full + 1] = (byte) (table[s[i + 1]] << 4 | table[s[i + 2]] >> 2);
case 1:
result[full] = (byte) (table[s[i]] << 2 | table[s[i + 1]] >> 4);
}
return result;
}
}