Base64.java

Go to the documentation of this file.

package org.xbmc.android.jsonrpc.io;

import java.util.Arrays;

public class Base64
{
        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
        // ****************************************************************************************

        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++] = '\r';
                                dArr[d++] = '\n';
                                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;
        }

        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 '\r', '\n') 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;
        }

        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] == '\r' ? 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
        // ****************************************************************************************

        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++] = '\r';
                                dArr[d++] = '\n';
                                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;
        }

        public final static byte[] decode(byte[] sArr)
        {
                // Check special case
                int sLen = sArr.length;

                // Count illegal characters (including '\r', '\n') 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;
        }


        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] == '\r' ? 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
        // ****************************************************************************************

        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));
        }

        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 '\r', '\n') 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;
        }

        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) == '\r' ? 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;
        }
}