std::string AlibabaCloud::PDS::Base64Encode()

in sdk/src/utils/Utils.cc [110:147]

• 31 lines of code
• 6 McCabe index (conditional complexity)

std::string AlibabaCloud::PDS::Base64Encode(const char *src, int len)
{
    if (!src || len == 0) {
        return "";
    }

    static const char *ENC = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    auto in = reinterpret_cast<const unsigned char *>(src);
    auto inLen = len;
    std::stringstream ss;
    while (inLen) {
        // first 6 bits of char 1
        ss << ENC[*in >> 2];
        if (!--inLen) {
            // last 2 bits of char 1, 4 bits of 0
            ss << ENC[(*in & 0x3) << 4];
            ss << '=';
            ss << '=';
            break;
        }
        // last 2 bits of char 1, first 4 bits of char 2
        ss << ENC[((*in & 0x3) << 4) | (*(in + 1) >> 4)];
        in++;
        if (!--inLen) {
            // last 4 bits of char 2, 2 bits of 0
            ss << ENC[(*in & 0xF) << 2];
            ss << '=';
            break;
        }
        // last 4 bits of char 2, first 2 bits of char 3
        ss << ENC[((*in & 0xF) << 2) | (*(in + 1) >> 6)];
        in++;
        // last 6 bits of char 3
        ss << ENC[*in & 0x3F];
        in++, inLen--;
    }
    return ss.str();
}