CharsetConverter.cpp 4.63 KB

#include <vector>
#include <iterator>
#include <algorithm>
#include <cstdint>
#include <iostream>
#include "../endianness.hpp"
#include "utf8.h"
#include "CharsetConverter.hpp"
#include "conversion_tables.hpp"

using namespace std;

const char DEFAULT_UNDEFINED_CHAR = static_cast<char>(0xF7);

string CharsetConverter::toString(const vector<uint32_t>& codepoints) const {
    string res;
    for (uint32_t cp : codepoints) {
        this->append(cp, res);
    }
    return res;
}

uint32_t UTF8CharsetConverter::peek(const char*& it, const char* end) const {
    return utf8::peek_next(it, end);
}

uint32_t UTF8CharsetConverter::next(const char*& it, const char* end) const {
    return utf8::next(it, end);
}

void UTF8CharsetConverter::append(uint32_t cp, string& result) const {
    utf8::append(cp, back_inserter(result));
}

UTF16CharsetConverter::UTF16CharsetConverter(UTF16CharsetConverter::Endianness endianness)
: endianness(endianness) {
    
}

static inline uint16_t swapBytes(uint16_t n) {
    return (((n & 0xff)<<8) | ((n & 0xff00)>>8));
}

uint16_t UTF16CharsetConverter::convertEndianness(uint16_t cp) const {
    return cp;
    if (this->endianness == BE) {
        return ntohs(cp);
    }
    else {
        return swapBytes(ntohs(cp));
    }
}

uint32_t UTF16CharsetConverter::peek(const char*& it, const char* end) const {
    /*
     * Borrowed from utfcpp
     */

    uint32_t cp = this->convertEndianness(utf8::internal::mask16(*it));
    // Take care of surrogate pairs first
    if (utf8::internal::is_lead_surrogate(cp)) {
        uint32_t trail_surrogate = this->convertEndianness(utf8::internal::mask16(*it));
        cp = (cp << 10) + trail_surrogate + utf8::internal::SURROGATE_OFFSET;
    }
    return cp;
}

uint32_t UTF16CharsetConverter::next(const char*& it, const char* end) const {

    /*
     * Borrowed from utfcpp
     */

    uint32_t cp = this->convertEndianness(utf8::internal::mask16(*it++));
    // Take care of surrogate pairs first
    if (utf8::internal::is_lead_surrogate(cp)) {
        uint32_t trail_surrogate = this->convertEndianness(utf8::internal::mask16(*it++));
        cp = (cp << 10) + trail_surrogate + utf8::internal::SURROGATE_OFFSET;
    }
    return cp;
}

static void appendWCharToString(uint16_t wchar, string& result) {
    uint8_t b[2] = {
        static_cast<uint8_t> (wchar & 0x00FF),
        static_cast<uint8_t> ((wchar & 0xFF00) >> 8)
    };
    char* chars = reinterpret_cast<char*> (b);
    result.push_back(chars[0]);
    result.push_back(chars[1]);
}

void UTF16CharsetConverter::append(uint32_t cp, string& result) const {
    /*
     * borrowed from utfcpp
     */
    if (cp > 0xffff) { //make a surrogate pair
        uint16_t wchar1 = static_cast<uint16_t> ((cp >> 10) + utf8::internal::LEAD_OFFSET);
        uint16_t wchar2 = static_cast<uint16_t> ((cp & 0x3ff) + utf8::internal::TRAIL_SURROGATE_MIN);
        appendWCharToString(wchar1, result);
        appendWCharToString(wchar2, result);
    } else {
        uint16_t wchar = static_cast<uint16_t> (cp);
        appendWCharToString(wchar, result);
    }
}

static vector<char> reverseArray(const uint32_t* array) {
    vector<char> res;
    unsigned char c = 0;
    do {
        uint32_t codepoint = array[c];
        res.resize(max(static_cast<uint32_t> (res.size()), codepoint + 1), DEFAULT_UNDEFINED_CHAR);
        res[codepoint] = static_cast<char> (c);
        c++;
    }    while (c != 255);
    return res;
}

OneByteCharsetConverter::OneByteCharsetConverter(const uint32_t* array)
: array(array),
codepoint2Char(reverseArray(array)) {
}

// TODO - sprawdzanie zakresu

uint32_t OneByteCharsetConverter::peek(const char*& it, const char* end) const {
    return this->array[static_cast<unsigned char> (*it)];
}

uint32_t OneByteCharsetConverter::next(const char*& it, const char* end) const {
    return this->array[static_cast<unsigned char> (*(it++))];
}

void OneByteCharsetConverter::append(uint32_t cp, std::string& result) const {
    if (cp < this->codepoint2Char.size()) {
        result.push_back(this->codepoint2Char[cp]);
    } else {
        result.push_back(DEFAULT_UNDEFINED_CHAR);
    }
}

ISO8859_2_CharsetConverter::ISO8859_2_CharsetConverter()
: OneByteCharsetConverter(ISO_8859_2_TO_CODEPOINT) {
}

Windows_1250_CharsetConverter::Windows_1250_CharsetConverter()
: OneByteCharsetConverter(WINDOWS_1250_TO_CODEPOINT) {
}

string CharsetConverter::fromUTF8(const string& input) const {
    string res;
    const char* currInput = input.c_str();
    const char* inputEnd = input.c_str() + input.length();
    cerr << input << endl;
    while (currInput != inputEnd) {
        uint32_t cp = utf8::next(currInput, inputEnd);
        this->append(cp, res);
    }
    return res;
}