Function Strs_init_from_list

python/stringzilla.c:7135–7273

The inefficient `Strs_init` path initializing from a Pythonic list of strings.

// The inefficient `Strs_init` path initializing from a Pythonic list of strings.
static int Strs_init_from_list(Strs *self, PyObject *sequence_obj, int view) {
    Py_ssize_t count = PyList_GET_SIZE(sequence_obj);

    // Handle empty list
    if (count == 0) {
        self->layout = STRS_FRAGMENTED;
        self->data.fragmented.count = 0;
        self->data.fragmented.spans = NULL;
        sz_memory_allocator_init_default(&self->data.fragmented.allocator);
        self->data.fragmented.parent = NULL;
        return 0;
    }

    // Zero-copy mode for Python sequences - use reordered layout for memory-scattered strings
    if (view) {
        // Initialize allocator for memory management
        sz_memory_allocator_t allocator;
        sz_memory_allocator_init_default(&allocator);

        sz_string_view_t *parts =
            (sz_string_view_t *)allocator.allocate(count * sizeof(sz_string_view_t), allocator.handle);
        if (!parts) {
            PyErr_NoMemory();
            return -1;
        }

        // Build views directly to the string data
        for (Py_ssize_t i = 0; i < count; i++) {
            PyObject *item = PyList_GET_ITEM(sequence_obj, i);

            // Export string data directly (no copying, just span)
            sz_cptr_t item_start;
            sz_size_t item_length;
            if (!sz_py_export_string_like(item, &item_start, &item_length)) {
                allocator.free(parts, count * sizeof(sz_string_view_t), allocator.handle);
                PyErr_Format(PyExc_TypeError, "Item %zd is not a string-like object", i);
                return -1;
            }

            parts[i].start = item_start;
            parts[i].length = item_length;
        }

        // Setup reordered layout with parent list to keep strings alive
        self->layout = STRS_FRAGMENTED;
        self->data.fragmented.count = count;
        self->data.fragmented.spans = parts;
        self->data.fragmented.allocator = allocator;
        self->data.fragmented.parent = sequence_obj; // Keep list alive
        Py_INCREF(sequence_obj);
        return 0;
    }
    // Allocate a new tape to fit all of the items
    else {

        // First pass: calculate total size needed
        sz_size_t total_bytes = 0;
        int use_64bit = 0;