herostools.actor.statemachine
=============================

.. py:module:: herostools.actor.statemachine

.. autoapi-nested-parse::

   # State Machine for HEROs

   This keeps a cache of the last known state of a datasource and
   allows to query this cache via a HTTP metrics endpoint. This is
   especially useful for scraping from prometheus or influxdb.


    * {observable}_time {return_value.time}
    * {observable}_value {return_value.value}
      if unit is not 'None' a label {unit='{{return_value.unit}}'} is attached
    * {observable}_raw_value {return_value.raw_value}
      if unit is not 'None' a label {unit='{{return_value.raw_unit}}'} is attached

   A predefined set of labels is attached to the metrics.
   Observable names are cleaned to match metric names [a-z0-9_]
    trailing _ and repetitions _ are removed.



Attributes
----------

.. autoapisummary::

   herostools.actor.statemachine.no_metric
   herostools.actor.statemachine.minify_metric
   herostools.actor.statemachine.allowed_types
   herostools.actor.statemachine.loop


Classes
-------

.. autoapisummary::

   herostools.actor.statemachine.HERODatasourceStateMachine


Module Contents
---------------

.. py:data:: no_metric

.. py:data:: minify_metric

.. py:data:: allowed_types

.. py:class:: HERODatasourceStateMachine(loop, *args, http_port: int = 9090, bind_address: str = 'localhost', metrics_endpoint='/metrics', object_selector: str = '*', labels: dict = {}, **kwargs)

   Bases: :py:obj:`heros.DatasourceObserver`


   A class that can observe and handle the data emitted by one or more datasource HEROs.
   In particular, this class provides an efficient way to listen to the data emitted by all datasource HEROs in
   the realm. By not instantiating the HEROs themselves but just subscribing to the topics for the datasource, this
   reduces the pressure on the backing zenoh network. If, however, only the data of a few HEROs should be observed,
   it might make more sense to just instantiate the according RemoteHEROs and connect a callback to their `observable_data`
   signal.

   :param object_selector: selector to specify which objects to observe. This becomes part of a zenoh selector and thus
   :param can be anything that makes sense in the selector. Defaults to * to observe all HEROs in the realm.:


   .. py:attribute:: cache


   .. py:attribute:: _http_port
      :value: 9090



   .. py:attribute:: _bind_address
      :value: 'localhost'



   .. py:attribute:: _metrics_endpoint
      :value: '/metrics'



   .. py:attribute:: _global_labels


   .. py:method:: _http_handle_metrics(request)
      :async:



   .. py:method:: _start_webserver()
      :async:



   .. py:method:: _metric_name(key)

      create a clean name for a metric without special characters matching [a-z0-9_].



   .. py:method:: _unit_name(unit)

      cleans units to not contain special characters



   .. py:method:: _update(source_name, data)

      update the values in the cache for source_name



   .. py:method:: _convert_to_metrics(dsrs: heros.datasource.types.DatasourceReturnSet, prefix=None)


   .. py:method:: get_cache()


   .. py:method:: clear()


.. py:data:: loop