package com.mxgraph.online; import java.util.Arrays; /** A very fast and memory efficient class to encode and decode to and from BASE64 in full accordance * with RFC 2045.<br><br> * On Windows XP sp1 with 1.4.2_04 and later ;), this encoder and decoder is about 10 times faster * on small arrays (10 - 1000 bytes) and 2-3 times as fast on larger arrays (10000 - 1000000 bytes) * compared to <code>sun.misc.Encoder()/Decoder()</code>.<br><br> * * On byte arrays the encoder is about 20% faster than Jakarta Commons Base64 Codec for encode and * about 50% faster for decoding large arrays. This implementation is about twice as fast on very small * arrays (< 30 bytes). If source/destination is a <code>String</code> this * version is about three times as fast due to the fact that the Commons Codec result has to be recoded * to a <code>String</code> from <code>byte[]</code>, which is very expensive.<br><br> * * This encode/decode algorithm doesn't create any temporary arrays as many other codecs do, it only * allocates the resulting array. This produces less garbage and it is possible to handle arrays twice * as large as algorithms that create a temporary array. (E.g. Jakarta Commons Codec). It is unknown * whether Sun's <code>sun.misc.Encoder()/Decoder()</code> produce temporary arrays but since performance * is quite low it probably does.<br><br> * * The encoder produces the same output as the Sun one except that the Sun's encoder appends * a trailing line separator if the last character isn't a pad. Unclear why but it only adds to the * length and is probably a side effect. Both are in conformance with RFC 2045 though.<br> * Commons codec seem to always att a trailing line separator.<br><br> * * <b>Note!</b> * The encode/decode method pairs (types) come in three versions with the <b>exact</b> same algorithm and * thus a lot of code redundancy. This is to not create any temporary arrays for transcoding to/from different * format types. The methods not used can simply be commented out.<br><br> * * There is also a "fast" version of all decode methods that works the same way as the normal ones, but * har a few demands on the decoded input. Normally though, these fast verions should be used if the source if * the input is known and it hasn't bee tampered with.<br><br> * * If you find the code useful or you find a bug, please send me a note at base64 @ miginfocom . com. * * Licence (BSD): * ============== * * Copyright (c) 2004, Mikael Grev, MiG InfoCom AB. (base64 @ miginfocom . com) * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list * of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this * list of conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * Neither the name of the MiG InfoCom AB nor the names of its contributors may be * used to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * @version 2.2 * @author Mikael Grev * Date: 2004-aug-02 * Time: 11:31:11 */ public class mxBase64 { private static final char[] CA = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" .toCharArray(); private static final int[] IA = new int[256]; static { Arrays.fill(IA, -1); for (int i = 0, iS = CA.length; i < iS; i++) IA[CA[i]] = i; IA['='] = 0; } // **************************************************************************************** // * char[] version // **************************************************************************************** /** Encodes a raw byte array into a BASE64 <code>char[]</code> representation i accordance with RFC 2045. * @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned. * @param lineSep Optional " " after 76 characters, unless end of file.<br> * No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a * little faster. * @return A BASE64 encoded array. Never <code>null</code>. */ public final static char[] encodeToChar(byte[] sArr, boolean lineSep) { // Check special case int sLen = sArr != null ? sArr.length : 0; if (sLen == 0) return new char[0]; int eLen = (sLen / 3) * 3; // Length of even 24-bits. int cCnt = ((sLen - 1) / 3 + 1) << 2; // Returned character count int dLen = cCnt + (lineSep ? (cCnt - 1) / 76 << 1 : 0); // Length of returned array char[] dArr = new char[dLen]; // Encode even 24-bits for (int s = 0, d = 0, cc = 0; s < eLen;) { // Copy next three bytes into lower 24 bits of int, paying attension to sign. int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff); // Encode the int into four chars dArr[d++] = CA[(i >>> 18) & 0x3f]; dArr[d++] = CA[(i >>> 12) & 0x3f]; dArr[d++] = CA[(i >>> 6) & 0x3f]; dArr[d++] = CA[i & 0x3f]; // Add optional line separator if (lineSep && ++cc == 19 && d < dLen - 2) { dArr[d++] = ' '; dArr[d++] = ' '; cc = 0; } } // Pad and encode last bits if source isn't even 24 bits. int left = sLen - eLen; // 0 - 2. if (left > 0) { // Prepare the int int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0); // Set last four chars dArr[dLen - 4] = CA[i >> 12]; dArr[dLen - 3] = CA[(i >>> 6) & 0x3f]; dArr[dLen - 2] = left == 2 ? CA[i & 0x3f] : '='; dArr[dLen - 1] = '='; } return dArr; } /** Decodes a BASE64 encoded char array. All illegal characters will be ignored and can handle both arrays with * and without line separators. * @param sArr The source array. <code>null</code> or length 0 will return an empty array. * @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters * (including '=') isn't divideable by 4. (I.e. definitely corrupted). */ public final static byte[] decode(char[] sArr) { // Check special case int sLen = sArr != null ? sArr.length : 0; if (sLen == 0) return new byte[0]; // Count illegal characters (including ' ', ' ') to know what size the returned array will be, // so we don't have to reallocate & copy it later. int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...) for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out. if (IA[sArr[i]] < 0) sepCnt++; // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045. if ((sLen - sepCnt) % 4 != 0) return null; int pad = 0; for (int i = sLen; i > 1 && IA[sArr[--i]] <= 0;) if (sArr[i] == '=') pad++; int len = ((sLen - sepCnt) * 6 >> 3) - pad; byte[] dArr = new byte[len]; // Preallocate byte[] of exact length for (int s = 0, d = 0; d < len;) { // Assemble three bytes into an int from four "valid" characters. int i = 0; for (int j = 0; j < 4; j++) { // j only increased if a valid char was found. int c = IA[sArr[s++]]; if (c >= 0) i |= c << (18 - j * 6); else j--; } // Add the bytes dArr[d++] = (byte) (i >> 16); if (d < len) { dArr[d++] = (byte) (i >> 8); if (d < len) dArr[d++] = (byte) i; } } return dArr; } /** Decodes a BASE64 encoded char array that is known to be resonably well formatted. The method is about twice as * fast as {@link #decode(char[])}. The preconditions are:<br> * + The array must have a line length of 76 chars OR no line separators at all (one line).<br> * + Line separator must be " ", as specified in RFC 2045 * + The array must not contain illegal characters within the encoded string<br> * + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br> * @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception. * @return The decoded array of bytes. May be of length 0. */ public final static byte[] decodeFast(char[] sArr) { // Check special case int sLen = sArr.length; if (sLen == 0) return new byte[0]; int sIx = 0, eIx = sLen - 1; // Start and end index after trimming. // Trim illegal chars from start while (sIx < eIx && IA[sArr[sIx]] < 0) sIx++; // Trim illegal chars from end while (eIx > 0 && IA[sArr[eIx]] < 0) eIx--; // get the padding count (=) (0, 1 or 2) int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end. int cCnt = eIx - sIx + 1; // Content count including possible separators int sepCnt = sLen > 76 ? (sArr[76] == ' ' ? cCnt / 78 : 0) << 1 : 0; int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes byte[] dArr = new byte[len]; // Preallocate byte[] of exact length // Decode all but the last 0 - 2 bytes. int d = 0; for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) { // Assemble three bytes into an int from four "valid" characters. int i = IA[sArr[sIx++]] << 18 | IA[sArr[sIx++]] << 12 | IA[sArr[sIx++]] << 6 | IA[sArr[sIx++]]; // Add the bytes dArr[d++] = (byte) (i >> 16); dArr[d++] = (byte) (i >> 8); dArr[d++] = (byte) i; // If line separator, jump over it. if (sepCnt > 0 && ++cc == 19) { sIx += 2; cc = 0; } } if (d < len) { // Decode last 1-3 bytes (incl '=') into 1-3 bytes int i = 0; for (int j = 0; sIx <= eIx - pad; j++) i |= IA[sArr[sIx++]] << (18 - j * 6); for (int r = 16; d < len; r -= 8) dArr[d++] = (byte) (i >> r); } return dArr; } // **************************************************************************************** // * byte[] version // **************************************************************************************** /** Encodes a raw byte array into a BASE64 <code>byte[]</code> representation i accordance with RFC 2045. * @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned. * @param lineSep Optional " " after 76 characters, unless end of file.<br> * No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a * little faster. * @return A BASE64 encoded array. Never <code>null</code>. */ public final static byte[] encodeToByte(byte[] sArr, boolean lineSep) { // Check special case int sLen = sArr != null ? sArr.length : 0; if (sLen == 0) return new byte[0]; int eLen = (sLen / 3) * 3; // Length of even 24-bits. int cCnt = ((sLen - 1) / 3 + 1) << 2; // Returned character count int dLen = cCnt + (lineSep ? (cCnt - 1) / 76 << 1 : 0); // Length of returned array byte[] dArr = new byte[dLen]; // Encode even 24-bits for (int s = 0, d = 0, cc = 0; s < eLen;) { // Copy next three bytes into lower 24 bits of int, paying attension to sign. int i = (sArr[s++] & 0xff) << 16 | (sArr[s++] & 0xff) << 8 | (sArr[s++] & 0xff); // Encode the int into four chars dArr[d++] = (byte) CA[(i >>> 18) & 0x3f]; dArr[d++] = (byte) CA[(i >>> 12) & 0x3f]; dArr[d++] = (byte) CA[(i >>> 6) & 0x3f]; dArr[d++] = (byte) CA[i & 0x3f]; // Add optional line separator if (lineSep && ++cc == 19 && d < dLen - 2) { dArr[d++] = ' '; dArr[d++] = ' '; cc = 0; } } // Pad and encode last bits if source isn't an even 24 bits. int left = sLen - eLen; // 0 - 2. if (left > 0) { // Prepare the int int i = ((sArr[eLen] & 0xff) << 10) | (left == 2 ? ((sArr[sLen - 1] & 0xff) << 2) : 0); // Set last four chars dArr[dLen - 4] = (byte) CA[i >> 12]; dArr[dLen - 3] = (byte) CA[(i >>> 6) & 0x3f]; dArr[dLen - 2] = left == 2 ? (byte) CA[i & 0x3f] : (byte) '='; dArr[dLen - 1] = '='; } return dArr; } /** Decodes a BASE64 encoded byte array. All illegal characters will be ignored and can handle both arrays with * and without line separators. * @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception. * @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters * (including '=') isn't divideable by 4. (I.e. definitely corrupted). */ public final static byte[] decode(byte[] sArr) { // Check special case int sLen = sArr.length; // Count illegal characters (including ' ', ' ') to know what size the returned array will be, // so we don't have to reallocate & copy it later. int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...) for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out. if (IA[sArr[i] & 0xff] < 0) sepCnt++; // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045. if ((sLen - sepCnt) % 4 != 0) return null; int pad = 0; for (int i = sLen; i > 1 && IA[sArr[--i] & 0xff] <= 0;) if (sArr[i] == '=') pad++; int len = ((sLen - sepCnt) * 6 >> 3) - pad; byte[] dArr = new byte[len]; // Preallocate byte[] of exact length for (int s = 0, d = 0; d < len;) { // Assemble three bytes into an int from four "valid" characters. int i = 0; for (int j = 0; j < 4; j++) { // j only increased if a valid char was found. int c = IA[sArr[s++] & 0xff]; if (c >= 0) i |= c << (18 - j * 6); else j--; } // Add the bytes dArr[d++] = (byte) (i >> 16); if (d < len) { dArr[d++] = (byte) (i >> 8); if (d < len) dArr[d++] = (byte) i; } } return dArr; } /** Decodes a BASE64 encoded byte array that is known to be resonably well formatted. The method is about twice as * fast as {@link #decode(byte[])}. The preconditions are:<br> * + The array must have a line length of 76 chars OR no line separators at all (one line).<br> * + Line separator must be " ", as specified in RFC 2045 * + The array must not contain illegal characters within the encoded string<br> * + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br> * @param sArr The source array. Length 0 will return an empty array. <code>null</code> will throw an exception. * @return The decoded array of bytes. May be of length 0. */ public final static byte[] decodeFast(byte[] sArr) { // Check special case int sLen = sArr.length; if (sLen == 0) return new byte[0]; int sIx = 0, eIx = sLen - 1; // Start and end index after trimming. // Trim illegal chars from start while (sIx < eIx && IA[sArr[sIx] & 0xff] < 0) sIx++; // Trim illegal chars from end while (eIx > 0 && IA[sArr[eIx] & 0xff] < 0) eIx--; // get the padding count (=) (0, 1 or 2) int pad = sArr[eIx] == '=' ? (sArr[eIx - 1] == '=' ? 2 : 1) : 0; // Count '=' at end. int cCnt = eIx - sIx + 1; // Content count including possible separators int sepCnt = sLen > 76 ? (sArr[76] == ' ' ? cCnt / 78 : 0) << 1 : 0; int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes byte[] dArr = new byte[len]; // Preallocate byte[] of exact length // Decode all but the last 0 - 2 bytes. int d = 0; for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) { // Assemble three bytes into an int from four "valid" characters. int i = IA[sArr[sIx++]] << 18 | IA[sArr[sIx++]] << 12 | IA[sArr[sIx++]] << 6 | IA[sArr[sIx++]]; // Add the bytes dArr[d++] = (byte) (i >> 16); dArr[d++] = (byte) (i >> 8); dArr[d++] = (byte) i; // If line separator, jump over it. if (sepCnt > 0 && ++cc == 19) { sIx += 2; cc = 0; } } if (d < len) { // Decode last 1-3 bytes (incl '=') into 1-3 bytes int i = 0; for (int j = 0; sIx <= eIx - pad; j++) i |= IA[sArr[sIx++]] << (18 - j * 6); for (int r = 16; d < len; r -= 8) dArr[d++] = (byte) (i >> r); } return dArr; } // **************************************************************************************** // * String version // **************************************************************************************** /** Encodes a raw byte array into a BASE64 <code>String</code> representation i accordance with RFC 2045. * @param sArr The bytes to convert. If <code>null</code> or length 0 an empty array will be returned. * @param lineSep Optional " " after 76 characters, unless end of file.<br> * No line separator will be in breach of RFC 2045 which specifies max 76 per line but will be a * little faster. * @return A BASE64 encoded array. Never <code>null</code>. */ public final static String encodeToString(byte[] sArr, boolean lineSep) { // Reuse char[] since we can't create a String incrementally anyway and StringBuffer/Builder would be slower. return new String(encodeToChar(sArr, lineSep)); } /** Decodes a BASE64 encoded <code>String</code>. All illegal characters will be ignored and can handle both strings with * and without line separators.<br> * <b>Note!</b> It can be up to about 2x the speed to call <code>decode(str.toCharArray())</code> instead. That * will create a temporary array though. This version will use <code>str.charAt(i)</code> to iterate the string. * @param str The source string. <code>null</code> or length 0 will return an empty array. * @return The decoded array of bytes. May be of length 0. Will be <code>null</code> if the legal characters * (including '=') isn't divideable by 4. (I.e. definitely corrupted). */ public final static byte[] decode(String str) { // Check special case int sLen = str != null ? str.length() : 0; if (sLen == 0) return new byte[0]; // Count illegal characters (including ' ', ' ') to know what size the returned array will be, // so we don't have to reallocate & copy it later. int sepCnt = 0; // Number of separator characters. (Actually illegal characters, but that's a bonus...) for (int i = 0; i < sLen; i++) // If input is "pure" (I.e. no line separators or illegal chars) base64 this loop can be commented out. if (IA[str.charAt(i)] < 0) sepCnt++; // Check so that legal chars (including '=') are evenly divideable by 4 as specified in RFC 2045. if ((sLen - sepCnt) % 4 != 0) return null; // Count '=' at end int pad = 0; for (int i = sLen; i > 1 && IA[str.charAt(--i)] <= 0;) if (str.charAt(i) == '=') pad++; int len = ((sLen - sepCnt) * 6 >> 3) - pad; byte[] dArr = new byte[len]; // Preallocate byte[] of exact length for (int s = 0, d = 0; d < len;) { // Assemble three bytes into an int from four "valid" characters. int i = 0; for (int j = 0; j < 4; j++) { // j only increased if a valid char was found. int c = IA[str.charAt(s++)]; if (c >= 0) i |= c << (18 - j * 6); else j--; } // Add the bytes dArr[d++] = (byte) (i >> 16); if (d < len) { dArr[d++] = (byte) (i >> 8); if (d < len) dArr[d++] = (byte) i; } } return dArr; } /** Decodes a BASE64 encoded string that is known to be resonably well formatted. The method is about twice as * fast as {@link #decode(String)}. The preconditions are:<br> * + The array must have a line length of 76 chars OR no line separators at all (one line).<br> * + Line separator must be " ", as specified in RFC 2045 * + The array must not contain illegal characters within the encoded string<br> * + The array CAN have illegal characters at the beginning and end, those will be dealt with appropriately.<br> * @param s The source string. Length 0 will return an empty array. <code>null</code> will throw an exception. * @return The decoded array of bytes. May be of length 0. */ public final static byte[] decodeFast(String s) { // Check special case int sLen = s.length(); if (sLen == 0) return new byte[0]; int sIx = 0, eIx = sLen - 1; // Start and end index after trimming. // Trim illegal chars from start while (sIx < eIx && IA[s.charAt(sIx) & 0xff] < 0) sIx++; // Trim illegal chars from end while (eIx > 0 && IA[s.charAt(eIx) & 0xff] < 0) eIx--; // get the padding count (=) (0, 1 or 2) int pad = s.charAt(eIx) == '=' ? (s.charAt(eIx - 1) == '=' ? 2 : 1) : 0; // Count '=' at end. int cCnt = eIx - sIx + 1; // Content count including possible separators int sepCnt = sLen > 76 ? (s.charAt(76) == ' ' ? cCnt / 78 : 0) << 1 : 0; int len = ((cCnt - sepCnt) * 6 >> 3) - pad; // The number of decoded bytes byte[] dArr = new byte[len]; // Preallocate byte[] of exact length // Decode all but the last 0 - 2 bytes. int d = 0; for (int cc = 0, eLen = (len / 3) * 3; d < eLen;) { // Assemble three bytes into an int from four "valid" characters. int i = IA[s.charAt(sIx++)] << 18 | IA[s.charAt(sIx++)] << 12 | IA[s.charAt(sIx++)] << 6 | IA[s.charAt(sIx++)]; // Add the bytes dArr[d++] = (byte) (i >> 16); dArr[d++] = (byte) (i >> 8); dArr[d++] = (byte) i; // If line separator, jump over it. if (sepCnt > 0 && ++cc == 19) { sIx += 2; cc = 0; } } if (d < len) { // Decode last 1-3 bytes (incl '=') into 1-3 bytes int i = 0; for (int j = 0; sIx <= eIx - pad; j++) i |= IA[s.charAt(sIx++)] << (18 - j * 6); for (int r = 16; d < len; r -= 8) dArr[d++] = (byte) (i >> r); } return dArr; } }