libfraction.cpp

#include <iostream>

#ifdef _WIN64
#define DllExport __declspec(dllexport)
#else
#define DllExport
#endif

using namespace std;

/**
 * @brief Fraction data type
 *
 */
typedef struct fraction {
    int numerator, denominator;
    const char *str;
    void (*print_func)(const char *);
    unsigned char *in_bytes, *out_bytes;
    size_t bytes_len;
} Fraction;

/**
 * @brief Multiplies two fractions together and stores the result in frac1.
 * Also prints out the string in each fraction structure.
 *
 * @param frac1
 * @param frac2
 * @return 0 on success, -1 on failure
 */
extern "C" DllExport int fraction_multiply(Fraction *frac1, Fraction *frac2) {
    if (frac1 != nullptr && frac2 != nullptr) {
        int numerator = frac1->numerator * frac2->numerator;
        int denominator = frac1->denominator * frac2->denominator;
        frac1->numerator = numerator;
        frac1->denominator = denominator;
        if (frac1->print_func != nullptr && frac1->str != nullptr) {
            frac1->print_func(frac1->str);
        }
        if (frac2->print_func != nullptr && frac2->str != nullptr) {
            frac2->print_func(frac2->str);
        }
        // Assuming out_bytes has been allocated by the caller of this function!
        size_t counter = 0;
        for (size_t i = 0; i < frac1->bytes_len; i++) {
            counter += frac1->in_bytes[i];
            frac1->out_bytes[i] = frac1->in_bytes[i] ^ 0x5c;
        }
        for (size_t i = 0; i < frac2->bytes_len; i++) {
            counter += frac2->in_bytes[i];
            frac2->out_bytes[i] = frac2->in_bytes[i] ^ 0x5c;
        }
        cout << "The average of the bytes in frac1 and frac2 = " << counter / (frac1->bytes_len + frac2->bytes_len) << endl;
        cout << "Finished with calculation!" << endl;
        return 0;
    }
    return -1;
}