int aws_xml_node_traverse()

in source/xml_parser.c [278:373]
73 lines of code
16 McCabe index (conditional complexity)

int aws_xml_node_traverse(
    struct aws_xml_parser *parser,
    struct aws_xml_node *node,
    aws_xml_parser_on_node_encountered_fn *on_node_encountered,
    void *user_data) {
    AWS_PRECONDITION(parser);
    AWS_PRECONDITION(node);

    if (on_node_encountered == NULL) {
        AWS_LOGF_ERROR(
            AWS_LS_COMMON_XML_PARSER, "Callback 'on_node_encountered' for aws_xml_node_traverse is invalid.");
        aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
        return AWS_OP_ERR;
    }

    node->processed = true;
    struct cb_stack_data stack_data = {
        .cb = on_node_encountered,
        .user_data = user_data,
    };

    size_t doc_depth = aws_array_list_length(&parser->callback_stack);
    if (doc_depth >= parser->max_depth) {
        AWS_LOGF_ERROR(AWS_LS_COMMON_XML_PARSER, "XML document is invalid.");
        parser->error = aws_raise_error(AWS_ERROR_MALFORMED_INPUT_STRING);
        return AWS_OP_ERR;
    }

    if (aws_array_list_push_back(&parser->callback_stack, &stack_data)) {
        AWS_LOGF_ERROR(AWS_LS_COMMON_XML_PARSER, "XML document is invalid.");
        parser->error = aws_raise_error(AWS_ERROR_MALFORMED_INPUT_STRING);
        return AWS_OP_ERR;
    }

    /* look for the next node at the current level. do this until we encounter the parent node's
     * closing tag. */
    while (!parser->stop_parsing && !parser->error) {
        uint8_t *next_location = memchr(parser->doc.ptr, '<', parser->doc.len);

        if (!next_location) {
            AWS_LOGF_ERROR(AWS_LS_COMMON_XML_PARSER, "XML document is invalid.");
            return aws_raise_error(AWS_ERROR_MALFORMED_INPUT_STRING);
        }

        uint8_t *end_location = memchr(parser->doc.ptr, '>', parser->doc.len);

        if (!end_location) {
            AWS_LOGF_ERROR(AWS_LS_COMMON_XML_PARSER, "XML document is invalid.");
            return aws_raise_error(AWS_ERROR_MALFORMED_INPUT_STRING);
        }

        bool parent_closed = false;

        if (*(next_location + 1) == '/') {
            parent_closed = true;
        }

        size_t node_name_len = end_location - next_location;

        aws_byte_cursor_advance(&parser->doc, end_location - parser->doc.ptr + 1);

        if (parent_closed) {
            break;
        }

        struct aws_byte_cursor decl_body = aws_byte_cursor_from_array(next_location + 1, node_name_len - 1);

        struct aws_xml_node next_node = {
            .doc_at_body = parser->doc,
            .processed = false,
        };

        if (s_load_node_decl(parser, &decl_body, &next_node)) {
            return AWS_OP_ERR;
        }

        if (!on_node_encountered(parser, &next_node, user_data)) {
            parser->stop_parsing = true;
            return parser->error;
        }

        /* if the user simply returned while skipping the node altogether, go ahead and do the skip over. */
        if (!parser->stop_parsing && !next_node.processed) {
            if (s_advance_to_closing_tag(parser, &next_node, NULL)) {
                return AWS_OP_ERR;
            }
        }
    }

    if (parser->stop_parsing) {
        return parser->error;
    }

    aws_array_list_pop_back(&parser->callback_stack);
    return parser->error;
}