interface TimeInterface

interface TimeInterface {
    
    /**
     * Returns the timestamp for the current request.
     *
     * This method should be used to obtain the current system time at the start
     * of the request. It will be the same value for the life of the request
     * (even for long execution times).
     *
     * If the request is not available it will fallback to the current system
     * time.
     *
     * This method can replace instances of
     * @code
     * $request_time = $_SERVER['REQUEST_TIME'];
     * $request_time = REQUEST_TIME;
     * $request_time = $requestStack->getCurrentRequest()->server->get('REQUEST_TIME');
     * $request_time = $request->server->get('REQUEST_TIME');
     * @endcode
     * and most instances of
     * @code
     * $time = time();
     * @endcode
     * with
     * @code
     * $request_time = \Drupal::time()->getRequestTime();
     * @endcode
     * or the equivalent using the injected service.
     *
     * Using the time service, rather than other methods, is especially important
     * when creating tests, which require predictable timestamps.
     *
     * @return int
     *   A Unix timestamp.
     *
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestMicroTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentMicroTime()
     */
    public function getRequestTime();
    
    /**
     * Returns the timestamp for the current request with microsecond precision.
     *
     * This method should be used to obtain the current system time, with
     * microsecond precision, at the start of the request. It will be the same
     * value for the life of the request (even for long execution times).
     *
     * If the request is not available it will fallback to the current system
     * time with microsecond precision.
     *
     * This method can replace instances of
     * @code
     * $request_time_float = $_SERVER['REQUEST_TIME_FLOAT'];
     * $request_time_float = $requestStack->getCurrentRequest()->server->get('REQUEST_TIME_FLOAT');
     * $request_time_float = $request->server->get('REQUEST_TIME_FLOAT');
     * @endcode
     * and many instances of
     * @code
     * $microtime = microtime();
     * $microtime = microtime(TRUE);
     * @endcode
     * with
     * @code
     * $request_time = \Drupal::time()->getRequestMicroTime();
     * @endcode
     * or the equivalent using the injected service.
     *
     * Using the time service, rather than other methods, is especially important
     * when creating tests, which require predictable timestamps.
     *
     * @return float
     *   A Unix timestamp with a fractional portion.
     *
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentMicroTime()
     */
    public function getRequestMicroTime();
    
    /**
     * Returns the current system time as an integer.
     *
     * This method should be used to obtain the current system time, at the time
     * the method was called.
     *
     * This method can replace many instances of
     * @code
     * $time = time();
     * @endcode
     * with
     * @code
     * $request_time = \Drupal::time()->getCurrentTime();
     * @endcode
     * or the equivalent using the injected service.
     *
     * This method should only be used when the current system time is actually
     * needed, such as with timers or time interval calculations. If only the
     * time at the start of the request is needed,
     * use TimeInterface::getRequestTime().
     *
     * Using the time service, rather than other methods, is especially important
     * when creating tests, which require predictable timestamps.
     *
     * @return int
     *   A Unix timestamp.
     *
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestMicroTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentMicroTime()
     */
    public function getCurrentTime();
    
    /**
     * Returns the current system time with microsecond precision.
     *
     * This method should be used to obtain the current system time, with
     * microsecond precision, at the time the method was called.
     *
     * This method can replace many instances of
     * @code
     * $microtime = microtime();
     * $microtime = microtime(TRUE);
     * @endcode
     * with
     * @code
     * $request_time = \Drupal::time()->getCurrentMicroTime();
     * @endcode
     * or the equivalent using the injected service.
     *
     * This method should only be used when the current system time is actually
     * needed, such as with timers or time interval calculations. If only the
     * time at the start of the request and microsecond precision is needed,
     * use TimeInterface::getRequestMicroTime().
     *
     * Using the time service, rather than other methods, is especially important
     * when creating tests, which require predictable timestamps.
     *
     * @return float
     *   A Unix timestamp with a fractional portion.
     *
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getRequestMicroTime()
     * @see \Drupal\Component\Datetime\TimeInterface::getCurrentTime()
     */
    public function getCurrentMicroTime();

}