Function array_from_text

numpy/core/src/multiarray/ctors.c:3363–3474

 */
#define FROM_BUFFER_SIZE 4096
static PyArrayObject *
array_from_text(PyArray_Descr *dtype, npy_intp num, char const *sep, size_t *nread,
                void *stream, next_element next, skip_separator skip_sep,
                void *stream_data)
{
    PyArrayObject *r;
    npy_intp i;
    char *dptr, *clean_sep, *tmp;
    int err = 0;
    int stop_reading_flag = 0;  /* -1 means end reached; -2 a parsing error */
    npy_intp thisbuf = 0;
    npy_intp size;
    npy_intp bytes, totalbytes;

    size = (num >= 0) ? num : FROM_BUFFER_SIZE;

    /*
     * Array creation may move sub-array dimensions from the dtype to array
     * dimensions, so we need to use the original dtype when reading.
     */
    Py_INCREF(dtype);

    r = (PyArrayObject *)
        PyArray_NewFromDescr(&PyArray_Type, dtype, 1, &size,
                             NULL, NULL, 0, NULL);
    if (r == NULL) {
        return NULL;
    }

    clean_sep = swab_separator(sep);
    if (clean_sep == NULL) {
        err = 1;
        goto fail;
    }

    NPY_BEGIN_ALLOW_THREADS;
    totalbytes = bytes = size * dtype->elsize;
    dptr = PyArray_DATA(r);
    for (i = 0; num < 0 || i < num; i++) {
        stop_reading_flag = next(&stream, dptr, dtype, stream_data);
        if (stop_reading_flag < 0) {
            break;
        }
        *nread += 1;
        thisbuf += 1;
        dptr += dtype->elsize;
        if (num < 0 && thisbuf == size) {
            totalbytes += bytes;
            /* The handler is always valid */
            tmp = PyDataMem_UserRENEW(PyArray_DATA(r), totalbytes,
                                  PyArray_HANDLER(r));
            if (tmp == NULL) {
                err = 1;
                break;
            }
            ((PyArrayObject_fields *)r)->data = tmp;
            dptr = tmp + (totalbytes - bytes);
            thisbuf = 0;