Function xmlOutputBufferWriteBase64

ThirdParty/libxml2/vtklibxml2/xmlwriter.c:1533–1602

* xmlOutputBufferWriteBase64: * @out: the xmlOutputBufferPtr * @data: binary data * @len: the number of bytes to encode * * Write base64 encoded data to an xmlOutputBuffer. * Adapted from John Walker's base64.c (http://www.fourmilab.ch/). * * Returns the bytes written (may be 0 because of buffering) or -1 in case of error */

 * Returns the bytes written (may be 0 because of buffering) or -1 in case of error
 */
static int
xmlOutputBufferWriteBase64(xmlOutputBufferPtr out, int len,
                           const unsigned char *data)
{
    static const unsigned char dtable[64] =
            {'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','+','/'};

    int i;
    int linelen;
    int count;
    int sum;

    if ((out == NULL) || (len < 0) || (data == NULL))
        return(-1);

    linelen = 0;
    sum = 0;

    i = 0;
    while (1) {
        unsigned char igroup[3];
        unsigned char ogroup[4];
        int c;
        int n;

        igroup[0] = igroup[1] = igroup[2] = 0;
        for (n = 0; n < 3 && i < len; n++, i++) {
            c = data[i];
            igroup[n] = (unsigned char) c;
        }

        if (n > 0) {
            ogroup[0] = dtable[igroup[0] >> 2];
            ogroup[1] = dtable[((igroup[0] & 3) << 4) | (igroup[1] >> 4)];
            ogroup[2] =
                dtable[((igroup[1] & 0xF) << 2) | (igroup[2] >> 6)];
            ogroup[3] = dtable[igroup[2] & 0x3F];

            if (n < 3) {
                ogroup[3] = '=';
                if (n < 2) {
                    ogroup[2] = '=';
                }
            }

            if (linelen >= B64LINELEN) {
                count = xmlOutputBufferWrite(out, 2, B64CRLF);
                if (count == -1)
                    return -1;
                sum += count;
                linelen = 0;
            }
            count = xmlOutputBufferWrite(out, 4, (const char *) ogroup);
            if (count == -1)