Function algorithm_sort

algorithm/algorithm.c:244–274

* @brief Sorts an array using a non-stable quicksort algorithm. * * @param base Pointer to the start of the array. * @param num Number of elements in the array. * @param size Size of each element in bytes. * @param comp Comparison function used to order the elements. */

 * @param comp Comparison function used to order the elements.
 */
void algorithm_sort(void *base, size_t num, size_t size, CompareFunc comp) {
    if (num <= 1 || size == 0 || base == NULL || comp == NULL) {
        ALGORITHM_LOG("[algorithm_sort] No sorting needed / invalid arguments.");
        return;
    }

    ALGORITHM_LOG("[algorithm_sort] Starting introsort for %zu elements.", num);

    /* Two 1-element scratch slots in one allocation: `tmp` for insertion/heap
     * moves and `pivot` for the partition pivot value. */
    void *scratch = malloc(size * 2);
    if (!scratch) {
        ALGORITHM_LOG("[algorithm_sort] Error: scratch allocation failed; array left unmodified.");
        return;
    }
    void *tmp   = scratch;
    void *pivot = (char *)scratch + size;

    /* Introspection depth limit: 2*floor(log2(num)). Beyond it, heapsort takes
     * over to guarantee O(n log n) even on adversarial input. */
    int depth = 0;
    for (size_t t = num; t > 1; t >>= 1) {
        ++depth;
    }
    depth *= 2;

    srt_introsort((char *)base, num, size, comp, tmp, pivot, depth);

    free(scratch);
    ALGORITHM_LOG("[algorithm_sort] Introsort completed.");
}


/**