convert.cxx

#include "convert.h"
#ifdef _WIN32
#include <windows.h>
#include <Winnls.h>
#endif
#include <iostream>
 
namespace cgv {
    namespace utils {
 
std::wstring str2wstr(const std::string& s)
{
    std::wstring ws;
    ws.resize(s.size());
#ifdef _WIN32
    if (!s.empty()) {
        int n = MultiByteToWideChar(CP_UTF8,0,s.c_str(),(int)s.size(),&ws[0],(int)ws.size());
        ws.resize(n);
    }
#else
    std::cerr << "str2wstr(const std::string& s) not implemented" << std::endl;
#endif
    return ws;
}
 
std::string wstr2str(const std::wstring& ws)
{
    std::string s;
    s.resize(4*ws.size());
#ifdef _WIN32
    if (!ws.empty()) {
        // BOOL default_char_used;
        char default_char = '#';
        int n = WideCharToMultiByte(CP_UTF8,0,ws.c_str(), (int)ws.size(),&s[0],(int)s.size(),NULL/*&default_char*/, NULL/*&default_char_used*/);
        if (n == 0) {
            switch (GetLastError()) {
            case ERROR_INSUFFICIENT_BUFFER : std::cerr << "A supplied buffer size was not large enough, or it was incorrectly set to NULL." << std::endl; break;
            case ERROR_INVALID_FLAGS : std::cerr << "The values supplied for flags were not valid." << std::endl; break;
            case ERROR_INVALID_PARAMETER : std::cerr << "Any of the parameter values was invalid." << std::endl; break;
            case ERROR_NO_UNICODE_TRANSLATION : std::cerr << "Invalid Unicode was found in a string." << std::endl; break;
            }
        }
        s.resize(n);
    }
#else
    std::cerr << "wstr2str(const std::wstring& ws) not implemented" << std::endl;
#endif
    return s;
}
 
static const std::string base64_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
 
 
static inline bool is_base64(unsigned char c) {
    return (isalnum(c) || (c == '+') || (c == '/'));
}
 
std::string encode_base64(const std::string& s) {
    std::string ret;
    int i = 0;
    int j = 0;
    unsigned char char_array_3[3];
    unsigned char char_array_4[4];
    const char* bytes_to_encode = s.c_str();
    size_t in_len = s.length();
    while (in_len--) {
        char_array_3[i++] = *(bytes_to_encode++);
        if (i == 3) {
            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
            char_array_4[3] = char_array_3[2] & 0x3f;
 
            for (i = 0; (i < 4); i++)
                ret += base64_chars[char_array_4[i]];
            i = 0;
        }
    }
 
    if (i)
    {
        for (j = i; j < 3; j++)
            char_array_3[j] = '\0';
 
        char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
        char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
        char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
        char_array_4[3] = char_array_3[2] & 0x3f;
 
        for (j = 0; (j < i + 1); j++)
            ret += base64_chars[char_array_4[j]];
 
        while ((i++ < 3))
            ret += '=';
 
    }
 
    return ret;
 
}
 
std::string decode_base64(std::string const& encoded_string) {
    int in_len = (int)encoded_string.size();
    int i = 0;
    int j = 0;
    int in_ = 0;
    unsigned char char_array_4[4], char_array_3[3];
    std::string ret;
 
    while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
        char_array_4[i++] = encoded_string[in_]; in_++;
        if (i == 4) {
            for (i = 0; i < 4; i++)
                char_array_4[i] = static_cast<unsigned char>(base64_chars.find(char_array_4[i]));
 
            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
 
            for (i = 0; (i < 3); i++)
                ret += char_array_3[i];
            i = 0;
        }
    }
 
    if (i) {
        for (j = i; j < 4; j++)
            char_array_4[j] = 0;
 
        for (j = 0; j < 4; j++)
            char_array_4[j] = static_cast<unsigned char>(base64_chars.find(char_array_4[j]));
 
        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
 
        for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
    }
 
    return ret;
}
 
    }
}