int s_advance_to_closing_tag()

in source/xml_parser.c [189:268]

• 63 lines of code
• 9 McCabe index (conditional complexity)

int s_advance_to_closing_tag(
    struct aws_xml_parser *parser,
    struct aws_xml_node *node,
    struct aws_byte_cursor *out_body) {
    AWS_PRECONDITION(parser);
    AWS_PRECONDITION(node);

    /* currently the max node name is 256 characters. This is arbitrary, but should be enough
     * for our uses. If we ever generalize this, we'll have to come back and rethink this. */
    uint8_t name_close[MAX_NAME_LEN + NODE_CLOSE_OVERHEAD] = {0};
    uint8_t name_open[MAX_NAME_LEN + NODE_CLOSE_OVERHEAD] = {0};

    struct aws_byte_buf closing_cmp_buf = aws_byte_buf_from_empty_array(name_close, sizeof(name_close));
    struct aws_byte_buf open_cmp_buf = aws_byte_buf_from_empty_array(name_open, sizeof(name_open));

    size_t closing_name_len = node->name.len + NODE_CLOSE_OVERHEAD;

    if (closing_name_len > node->doc_at_body.len) {
        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 (sizeof(name_close) < closing_name_len) {
        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;
    }

    struct aws_byte_cursor open_bracket = aws_byte_cursor_from_c_str("<");
    struct aws_byte_cursor close_token = aws_byte_cursor_from_c_str("/");
    struct aws_byte_cursor close_bracket = aws_byte_cursor_from_c_str(">");

    aws_byte_buf_append(&open_cmp_buf, &open_bracket);
    aws_byte_buf_append(&open_cmp_buf, &node->name);

    aws_byte_buf_append(&closing_cmp_buf, &open_bracket);
    aws_byte_buf_append(&closing_cmp_buf, &close_token);
    aws_byte_buf_append(&closing_cmp_buf, &node->name);
    aws_byte_buf_append(&closing_cmp_buf, &close_bracket);

    size_t depth_count = 1;
    struct aws_byte_cursor to_find_open = aws_byte_cursor_from_buf(&open_cmp_buf);
    struct aws_byte_cursor to_find_close = aws_byte_cursor_from_buf(&closing_cmp_buf);
    struct aws_byte_cursor close_find_result;
    AWS_ZERO_STRUCT(close_find_result);
    do {
        if (aws_byte_cursor_find_exact(&parser->doc, &to_find_close, &close_find_result)) {
            AWS_LOGF_ERROR(AWS_LS_COMMON_XML_PARSER, "XML document is invalid.");
            return aws_raise_error(AWS_ERROR_MALFORMED_INPUT_STRING);
        }

        /* if we find an opening node with the same name, before the closing tag keep going. */
        struct aws_byte_cursor open_find_result;
        AWS_ZERO_STRUCT(open_find_result);

        while (parser->doc.len) {
            if (!aws_byte_cursor_find_exact(&parser->doc, &to_find_open, &open_find_result)) {
                if (open_find_result.ptr < close_find_result.ptr) {
                    size_t skip_len = open_find_result.ptr - parser->doc.ptr;
                    aws_byte_cursor_advance(&parser->doc, skip_len + 1);
                    depth_count++;
                    continue;
                }
            }
            size_t skip_len = close_find_result.ptr - parser->doc.ptr;
            aws_byte_cursor_advance(&parser->doc, skip_len + closing_cmp_buf.len);
            depth_count--;
            break;
        }
    } while (depth_count > 0);

    size_t len = close_find_result.ptr - node->doc_at_body.ptr;

    if (out_body) {
        *out_body = aws_byte_cursor_from_array(node->doc_at_body.ptr, len);
    }

    return parser->error;
}