Function parse_and_intersect_capabilities

python/stringzillas.c:278–344

* @brief Parse capabilities from a Python tuple of strings and intersect with hardware capabilities. * @param[in] caps_tuple Python tuple containing capability strings (e.g., ('serial', 'haswell')). * @param[out] result Output capability mask after intersection with hardware capabilities. * @return 0 on success, -1 on error (with Python exception set). */

 *  @return 0 on success, -1 on error (with Python exception set).
 */
static int parse_and_intersect_capabilities(PyObject *caps_obj, sz_capability_t *result) {
    // Handle `DeviceScope` objects
    if (PyObject_IsInstance(caps_obj, (PyObject *)&DeviceScopeType)) {
        DeviceScope *device_scope = (DeviceScope *)caps_obj;

        // Try to get GPU device
        sz_size_t gpu_device;
        char const *error_detail_gpu = NULL;
        if (szs_device_scope_get_gpu_device(device_scope->handle, &gpu_device, &error_detail_gpu) == sz_success_k) {
            if (default_hardware_capabilities & sz_caps_cuda_k) {
                *result = sz_caps_cuda_k & default_hardware_capabilities;
                return 0;
            }
            else {
                PyErr_SetString(PyExc_RuntimeError, "GPU DeviceScope requested but CUDA not available");
                return -1;
            }
        }

        // Try to get CPU cores first
        sz_size_t cpu_cores;
        char const *error_detail_cpu = NULL;
        if (szs_device_scope_get_cpu_cores(device_scope->handle, &cpu_cores, &error_detail_cpu) == sz_success_k) {
            *result = sz_caps_cpus_k & default_hardware_capabilities;
            return 0;
        }

        // Default scope - use all available capabilities
        *result = default_hardware_capabilities;
        return 0;
    }

    // Handle tuple of capability strings (original behavior)
    if (!PyTuple_Check(caps_obj)) {
        PyErr_SetString(PyExc_TypeError, "capabilities must be a tuple of strings or a DeviceScope object");
        return -1;
    }

    sz_capability_t requested_caps = 0;
    Py_ssize_t n = PyTuple_Size(caps_obj);

    for (Py_ssize_t i = 0; i < n; i++) {
        PyObject *item = PyTuple_GET_ITEM(caps_obj, i);
        if (!PyUnicode_Check(item)) {
            PyErr_SetString(PyExc_TypeError, "capabilities must be a tuple of strings");
            return -1;
        }

        char const *cap_str = PyUnicode_AsUTF8(item);
        if (!cap_str) return -1;

        sz_capability_t flag = sz_capability_from_string_implementation_(cap_str);
        if (flag == sz_caps_none_k) {
            PyErr_Format(PyExc_ValueError, "Unknown capability: %s", cap_str);
            return -1;
        }
        requested_caps |= flag;
    }