juham.ts

Module: MQTT to Time Series Database Recorder

Description: Classes in this module povide functionality to subscribe to MQTT topics and record the received data into a time series database. Designed to facilitate seamless integration between MQTT-based data sources and time series databases, enabling efficient storage and retrieval of time-stamped data.

class juham.ts.ForecastRecord(name='forecastrecord')[source]

Bases: Base

Forecast database record.

This class listens the forecast topic and writes to the time series database.

app_name = 'juham'
classmethod classattrs_from_dict(attributes)

Set class attributes from a dictionary.

classmethod classattrs_to_dict()

Convert class attributes to a dictionary.

config_folder = 'config'
copy()

Create and return a copy of the current object.

This method serializes the current object to a dictionary using the to_dict method, creates a new instance of the object’s class, and populates it with the serialized data using the from_dict method.

This method uses class identifier based instantiation (see factory method pattern) to create a new instance of the object, and ‘to_dict’ and ‘from_dict’ methods to initialize object’s state.

Returns:

A new instance of the object’s class with the same state as the original object.

Example:

john = Human("john")
john.height = 1.8
john.age = 62
clone_of_john = john.copy()
database_class_id: str | None = 0
database_client: object | None
debug(msg, details='')

Logs the given debug message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

deserialize_from_json(f)

Load attributes from a JSON file.

epoc2utc(epoch)

Converts the given epoch time to UTC time string. All time coordinates are represented in UTC time. This allows the time coordinate to be mapped to any local time representation without ambiguity.

Parameters:

  • epoch (float) – timestamp in UTC time

  • rc (str) – time string describing date, time and time zone e.g 2024-07-08T12:10:22Z

Returns:

UTC time

error(msg, details='')

Logs the given error message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

classmethod find_class(class_id)

Given class identifier find the registered class. If no class with the give identifier exists return None.

Parameters:

class_id (int) – class identifier

Returns:

class or null if not registered

Return type:

obj (obj)

from_dict(data)

Update instance attributes from a dictionary.

classmethod get_class_id()

Return the class id of the class. Each class has an unique identifier that can be used for instantiating the class via Object.instantiate() method.

Parameters:

cls (class) – class

Return type:

str

Returns:

id (int) unique class identifier through which the class can be instantiated by factory method pattern.

classmethod get_json_file()

Generate the JSON file name based on the class name.

The file is created into users home folder.

info(msg, details='')

Logs the given information message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

Example:

obj = new Base('test')
obj.info('Message arrived', str(msg))
init_database(name)

Instantiates the configured time series database object.

Issues a warning if the database_class_id has not been configured, in which case the object will not have the time series recording feature.

This method is called internally and typically there is no need to call it from the application code.

Return type:

None

init_mqtt(name)

Instantiates the configured MQTT object for networking.

This method is called internally and typically there is no need to call it from the application code.

Issues a warning if the pubsub_class_id has not been configured, even though objects without a capability to communicate are rather crippled.

Return type:

None

classmethod initialize_class()

Initialize the class for instantiation, if not initialized already. This method initializes the class identifier and deserializes the public attributes from the specified configuration folder.

Returns:

returns true if the class was initialized, false implies the class is already initialized in which case the method call has no effect.

Return type:

bool

classmethod instantiate(class_id)

Given class identifier create the corresponding object. This method implements so called factory method pattern.

Parameters:

class_id (int) – class identifier

Returns:

instance of the given class.

Return type:

obj (obj)

classmethod instantiate_with_param(class_id, param)

Given class identifier and one constructor argument create the corresponding object.

Parameters:

  • class_id (str | None) – class identifier

  • param (Any) – class specific constructor parameter

Returns:

instance of the given class.

Return type:

obj

classmethod is_abstract()

Check whether the class is abstract or real. Override in the derived sub-classes. The default is False.

Return type:

bool

Returns:

True (bool) if abstract

is_time_between(begin_time, end_time, check_time=None)

Check if the given time is within the given time line. All timestamps must be in UTC time.

Parameters:

  • begin_time (timestamp) – beginning of the timeline

  • end_time (timestamp) – end of the timeline

  • check_time (timestamp) – time to be checked

Returns:

True if within the timeline

Return type:

rc (bool)

classmethod load_from_json()

Load class attributes from a JSON file.

log_message(type, msg, details='')

Publish the given log message to the MQTT ‘log’ topic.

This method constructs a log message with a timestamp, class type, source name, message, and optional details. It then publishes this message to the ‘log’ topic using the MQTT protocol.

Parameters:

  • type – str The classification or type of the log message (e.g., ‘Error’, ‘Info’).

  • msg – str The main log message to be published.

  • details – str, optional Additional details about the log message (default is an empty string).

Returns:

None

Raises:

Exception – If there is an issue with the MQTT client while publishing the message.

Example:

# publish info message to the Juham's 'log' topic
self.log_message("Info", f"Some cool message {some_stuff}", str(dict))
mqtt_class_id: str | None = None
mqtt_host: str = 'localhost'
mqtt_port: int = 1883
mqtt_root_topic: str = 'juham'
on_connect(client, userdata, flags, rc)[source]

Standard mqtt connect notification.

This method is called when the client connection with the MQTT broker is established.

on_disconnect(client, userdata, rc=0)

Notification on disconnect.

This method is called whenever the MQTT broker is disconnected. For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • rc (int) – See MQTT docs

on_message(client, userdata, msg)[source]

Standard mqtt message notification method.

This method is called upon new arrived message.

classmethod parse_args()

Parse the startup arguments defined by this class.

Return type:

None

pubsub_class_id = 0
read(point)

Reads the given measurement from the database.

Parameters:

point – point with initialized time stamp.

… note: NOT IMPLEMENTED YET

classmethod register()[source]

Register the class to the class database.

Once registered the class can be instantiated by its class identifier. Note that this method is called automatically by the system when the python loads the class. In this method sub classes should prepare themselves for instantiation by initializing their class attributes, for example.

classmethod register_class(class_id, ctor)

Register the given class identifier for identifier based instantiation . This, factory method pattern, as it is called, decouples the actual implementation from the interface. For more information see instantiate() method.

Parameters:

  • class_id (str) – class identifier

  • ctor (function) – constructor

run()

Start a new thread to runs the network loop in the background.

Allows the main program to continue executing while the MQTT client handles incoming and outgoing messages in the background.

run_forever()

Starts the network loop and blocks the main thread, continuously running the loop to process MQTT messages.

The loop will run indefinitely unless the connection is lost or the program is terminated.

classmethod save_to_json()

Create class configuration file, if the file does not exist yet.

serialize_to_json(f)

Serialize.

classmethod set_log(l)

Set logger.

Parameters:

l (logger) – logger object

Return type:

None

shutdown()

Shut down all services, free resources, stop threads, disconnect from mqtt, in general, prepare for shutdown.

subscribe(topic)

Subscribe to the given MQTT topic.

This method sets up the subscription to the specified MQTT topic and registers the on_message() method as the callback for incoming messages.

Parameters:

topic (str) – The MQTT topic to subscribe to.

Return type:

None

Example:

# configure
obj.subscribe('foo/bar')
timestamp()

Returns the current date-time in UTC.

Returns:

datetime in UTC.

Return type:

rc (datetime)

timestampstr(ts)

Converts the given timestamp to human readable string of form ‘Y-m-d H:M:S’.

Parameters:

ts (timestamp) – time stamp to be converted

Returns:

human readable date-time string

Return type:

rc (string)

to_dict()

Convert instance attributes to a dictionary.

warning(msg, details='')

Logs the given warning message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

write(point)

Writes the given measurement to the database. In case of an error, it tries again until the maximum number of attempts is reached. If it is still unsuccessful, it gives up and passes the first encountered exception to the caller.

Parameters:

point – a measurement describing a time stamp and related attributes for one measurement.

write_attempts = 3
class juham.ts.LogRecord(name='log_record')[source]

Bases: Base

Time series class for log events.

Records all log events to time series database.

app_name = 'juham'
classmethod classattrs_from_dict(attributes)

Set class attributes from a dictionary.

classmethod classattrs_to_dict()

Convert class attributes to a dictionary.

config_folder = 'config'
copy()

Create and return a copy of the current object.

This method serializes the current object to a dictionary using the to_dict method, creates a new instance of the object’s class, and populates it with the serialized data using the from_dict method.

This method uses class identifier based instantiation (see factory method pattern) to create a new instance of the object, and ‘to_dict’ and ‘from_dict’ methods to initialize object’s state.

Returns:

A new instance of the object’s class with the same state as the original object.

Example:

john = Human("john")
john.height = 1.8
john.age = 62
clone_of_john = john.copy()
database_class_id: str | None = 0
database_client: object | None
debug(msg, details='')

Logs the given debug message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

deserialize_from_json(f)

Load attributes from a JSON file.

epoc2utc(epoch)

Converts the given epoch time to UTC time string. All time coordinates are represented in UTC time. This allows the time coordinate to be mapped to any local time representation without ambiguity.

Parameters:

  • epoch (float) – timestamp in UTC time

  • rc (str) – time string describing date, time and time zone e.g 2024-07-08T12:10:22Z

Returns:

UTC time

error(msg, details='')

Logs the given error message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

classmethod find_class(class_id)

Given class identifier find the registered class. If no class with the give identifier exists return None.

Parameters:

class_id (int) – class identifier

Returns:

class or null if not registered

Return type:

obj (obj)

from_dict(data)

Update instance attributes from a dictionary.

classmethod get_class_id()

Return the class id of the class. Each class has an unique identifier that can be used for instantiating the class via Object.instantiate() method.

Parameters:

cls (class) – class

Return type:

str

Returns:

id (int) unique class identifier through which the class can be instantiated by factory method pattern.

classmethod get_json_file()

Generate the JSON file name based on the class name.

The file is created into users home folder.

info(msg, details='')

Logs the given information message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

Example:

obj = new Base('test')
obj.info('Message arrived', str(msg))
init_database(name)

Instantiates the configured time series database object.

Issues a warning if the database_class_id has not been configured, in which case the object will not have the time series recording feature.

This method is called internally and typically there is no need to call it from the application code.

Return type:

None

init_mqtt(name)

Instantiates the configured MQTT object for networking.

This method is called internally and typically there is no need to call it from the application code.

Issues a warning if the pubsub_class_id has not been configured, even though objects without a capability to communicate are rather crippled.

Return type:

None

classmethod initialize_class()

Initialize the class for instantiation, if not initialized already. This method initializes the class identifier and deserializes the public attributes from the specified configuration folder.

Returns:

returns true if the class was initialized, false implies the class is already initialized in which case the method call has no effect.

Return type:

bool

classmethod instantiate(class_id)

Given class identifier create the corresponding object. This method implements so called factory method pattern.

Parameters:

class_id (int) – class identifier

Returns:

instance of the given class.

Return type:

obj (obj)

classmethod instantiate_with_param(class_id, param)

Given class identifier and one constructor argument create the corresponding object.

Parameters:

  • class_id (str | None) – class identifier

  • param (Any) – class specific constructor parameter

Returns:

instance of the given class.

Return type:

obj

classmethod is_abstract()

Check whether the class is abstract or real. Override in the derived sub-classes. The default is False.

Return type:

bool

Returns:

True (bool) if abstract

is_time_between(begin_time, end_time, check_time=None)

Check if the given time is within the given time line. All timestamps must be in UTC time.

Parameters:

  • begin_time (timestamp) – beginning of the timeline

  • end_time (timestamp) – end of the timeline

  • check_time (timestamp) – time to be checked

Returns:

True if within the timeline

Return type:

rc (bool)

classmethod load_from_json()

Load class attributes from a JSON file.

log_message(type, msg, details='')

Publish the given log message to the MQTT ‘log’ topic.

This method constructs a log message with a timestamp, class type, source name, message, and optional details. It then publishes this message to the ‘log’ topic using the MQTT protocol.

Parameters:

  • type – str The classification or type of the log message (e.g., ‘Error’, ‘Info’).

  • msg – str The main log message to be published.

  • details – str, optional Additional details about the log message (default is an empty string).

Returns:

None

Raises:

Exception – If there is an issue with the MQTT client while publishing the message.

Example:

# publish info message to the Juham's 'log' topic
self.log_message("Info", f"Some cool message {some_stuff}", str(dict))
mqtt_class_id: str | None = None
mqtt_host: str = 'localhost'
mqtt_port: int = 1883
mqtt_root_topic: str = 'juham'
on_connect(client, userdata, flags, rc)[source]

Connects the client to mqtt broker.

Parameters:

  • client (obj) – client to be connected

  • userdata (any) – caller specific data

  • flags (int) – implementation specific shit

Returns:

True if succesful

Return type:

rc (bool)

on_disconnect(client, userdata, rc=0)

Notification on disconnect.

This method is called whenever the MQTT broker is disconnected. For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • rc (int) – See MQTT docs

on_message(client, userdata, msg)[source]

MQTT message notification on arrived message.

Called whenever a new message is posted on one of the topics the object has subscribed to via subscribe() method. This method is the heart of automation: here, derived subclasses should automate whatever they were designed to automate. For example, they could switch a relay when a boiler temperature sensor signals that the temperature is too low for a comforting shower for say one’s lovely wife.

For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • msg (object) – The MQTT message

classmethod parse_args()

Parse the startup arguments defined by this class.

Return type:

None

pubsub_class_id = 0
read(point)

Reads the given measurement from the database.

Parameters:

point – point with initialized time stamp.

… note: NOT IMPLEMENTED YET

classmethod register()[source]

Register the class to the class database.

Once registered the class can be instantiated by its class identifier. Note that this method is called automatically by the system when the python loads the class. In this method sub classes should prepare themselves for instantiation by initializing their class attributes, for example.

classmethod register_class(class_id, ctor)

Register the given class identifier for identifier based instantiation . This, factory method pattern, as it is called, decouples the actual implementation from the interface. For more information see instantiate() method.

Parameters:

  • class_id (str) – class identifier

  • ctor (function) – constructor

run()

Start a new thread to runs the network loop in the background.

Allows the main program to continue executing while the MQTT client handles incoming and outgoing messages in the background.

run_forever()

Starts the network loop and blocks the main thread, continuously running the loop to process MQTT messages.

The loop will run indefinitely unless the connection is lost or the program is terminated.

classmethod save_to_json()

Create class configuration file, if the file does not exist yet.

serialize_to_json(f)

Serialize.

classmethod set_log(l)

Set logger.

Parameters:

l (logger) – logger object

Return type:

None

shutdown()

Shut down all services, free resources, stop threads, disconnect from mqtt, in general, prepare for shutdown.

subscribe(topic)

Subscribe to the given MQTT topic.

This method sets up the subscription to the specified MQTT topic and registers the on_message() method as the callback for incoming messages.

Parameters:

topic (str) – The MQTT topic to subscribe to.

Return type:

None

Example:

# configure
obj.subscribe('foo/bar')
timestamp()

Returns the current date-time in UTC.

Returns:

datetime in UTC.

Return type:

rc (datetime)

timestampstr(ts)

Converts the given timestamp to human readable string of form ‘Y-m-d H:M:S’.

Parameters:

ts (timestamp) – time stamp to be converted

Returns:

human readable date-time string

Return type:

rc (string)

to_dict()

Convert instance attributes to a dictionary.

warning(msg, details='')

Logs the given warning message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

write(point)

Writes the given measurement to the database. In case of an error, it tries again until the maximum number of attempts is reached. If it is still unsuccessful, it gives up and passes the first encountered exception to the caller.

Parameters:

point – a measurement describing a time stamp and related attributes for one measurement.

write_attempts = 3
class juham.ts.PowerPlanRecord(name='powerplanrecord')[source]

Bases: Base

Power plan time series record.

Listens powerplan topic and updates time series database accordingly.

app_name = 'juham'
classmethod classattrs_from_dict(attributes)

Set class attributes from a dictionary.

classmethod classattrs_to_dict()

Convert class attributes to a dictionary.

config_folder = 'config'
copy()

Create and return a copy of the current object.

This method serializes the current object to a dictionary using the to_dict method, creates a new instance of the object’s class, and populates it with the serialized data using the from_dict method.

This method uses class identifier based instantiation (see factory method pattern) to create a new instance of the object, and ‘to_dict’ and ‘from_dict’ methods to initialize object’s state.

Returns:

A new instance of the object’s class with the same state as the original object.

Example:

john = Human("john")
john.height = 1.8
john.age = 62
clone_of_john = john.copy()
database_class_id: str | None = 0
database_client: object | None
debug(msg, details='')

Logs the given debug message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

deserialize_from_json(f)

Load attributes from a JSON file.

epoc2utc(epoch)

Converts the given epoch time to UTC time string. All time coordinates are represented in UTC time. This allows the time coordinate to be mapped to any local time representation without ambiguity.

Parameters:

  • epoch (float) – timestamp in UTC time

  • rc (str) – time string describing date, time and time zone e.g 2024-07-08T12:10:22Z

Returns:

UTC time

error(msg, details='')

Logs the given error message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

classmethod find_class(class_id)

Given class identifier find the registered class. If no class with the give identifier exists return None.

Parameters:

class_id (int) – class identifier

Returns:

class or null if not registered

Return type:

obj (obj)

from_dict(data)

Update instance attributes from a dictionary.

classmethod get_class_id()

Return the class id of the class. Each class has an unique identifier that can be used for instantiating the class via Object.instantiate() method.

Parameters:

cls (class) – class

Return type:

str

Returns:

id (int) unique class identifier through which the class can be instantiated by factory method pattern.

classmethod get_json_file()

Generate the JSON file name based on the class name.

The file is created into users home folder.

info(msg, details='')

Logs the given information message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

Example:

obj = new Base('test')
obj.info('Message arrived', str(msg))
init_database(name)

Instantiates the configured time series database object.

Issues a warning if the database_class_id has not been configured, in which case the object will not have the time series recording feature.

This method is called internally and typically there is no need to call it from the application code.

Return type:

None

init_mqtt(name)

Instantiates the configured MQTT object for networking.

This method is called internally and typically there is no need to call it from the application code.

Issues a warning if the pubsub_class_id has not been configured, even though objects without a capability to communicate are rather crippled.

Return type:

None

classmethod initialize_class()

Initialize the class for instantiation, if not initialized already. This method initializes the class identifier and deserializes the public attributes from the specified configuration folder.

Returns:

returns true if the class was initialized, false implies the class is already initialized in which case the method call has no effect.

Return type:

bool

classmethod instantiate(class_id)

Given class identifier create the corresponding object. This method implements so called factory method pattern.

Parameters:

class_id (int) – class identifier

Returns:

instance of the given class.

Return type:

obj (obj)

classmethod instantiate_with_param(class_id, param)

Given class identifier and one constructor argument create the corresponding object.

Parameters:

  • class_id (str | None) – class identifier

  • param (Any) – class specific constructor parameter

Returns:

instance of the given class.

Return type:

obj

classmethod is_abstract()

Check whether the class is abstract or real. Override in the derived sub-classes. The default is False.

Return type:

bool

Returns:

True (bool) if abstract

is_time_between(begin_time, end_time, check_time=None)

Check if the given time is within the given time line. All timestamps must be in UTC time.

Parameters:

  • begin_time (timestamp) – beginning of the timeline

  • end_time (timestamp) – end of the timeline

  • check_time (timestamp) – time to be checked

Returns:

True if within the timeline

Return type:

rc (bool)

classmethod load_from_json()

Load class attributes from a JSON file.

log_message(type, msg, details='')

Publish the given log message to the MQTT ‘log’ topic.

This method constructs a log message with a timestamp, class type, source name, message, and optional details. It then publishes this message to the ‘log’ topic using the MQTT protocol.

Parameters:

  • type – str The classification or type of the log message (e.g., ‘Error’, ‘Info’).

  • msg – str The main log message to be published.

  • details – str, optional Additional details about the log message (default is an empty string).

Returns:

None

Raises:

Exception – If there is an issue with the MQTT client while publishing the message.

Example:

# publish info message to the Juham's 'log' topic
self.log_message("Info", f"Some cool message {some_stuff}", str(dict))
mqtt_class_id: str | None = None
mqtt_host: str = 'localhost'
mqtt_port: int = 1883
mqtt_root_topic: str = 'juham'
on_connect(client, userdata, flags, rc)[source]

Notification on connect.

This method is called whenever the MQTT broker is connected. For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • flags (int) – Consult MQTT

  • rc (int) – See MQTT docs

on_disconnect(client, userdata, rc=0)

Notification on disconnect.

This method is called whenever the MQTT broker is disconnected. For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • rc (int) – See MQTT docs

on_message(client, userdata, msg)[source]

MQTT message notification on arrived message.

Called whenever a new message is posted on one of the topics the object has subscribed to via subscribe() method. This method is the heart of automation: here, derived subclasses should automate whatever they were designed to automate. For example, they could switch a relay when a boiler temperature sensor signals that the temperature is too low for a comforting shower for say one’s lovely wife.

For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • msg (object) – The MQTT message

classmethod parse_args()

Parse the startup arguments defined by this class.

Return type:

None

pubsub_class_id = 0
read(point)

Reads the given measurement from the database.

Parameters:

point – point with initialized time stamp.

… note: NOT IMPLEMENTED YET

classmethod register()[source]

Register the class to the class database.

Once registered the class can be instantiated by its class identifier. Note that this method is called automatically by the system when the python loads the class. In this method sub classes should prepare themselves for instantiation by initializing their class attributes, for example.

classmethod register_class(class_id, ctor)

Register the given class identifier for identifier based instantiation . This, factory method pattern, as it is called, decouples the actual implementation from the interface. For more information see instantiate() method.

Parameters:

  • class_id (str) – class identifier

  • ctor (function) – constructor

run()

Start a new thread to runs the network loop in the background.

Allows the main program to continue executing while the MQTT client handles incoming and outgoing messages in the background.

run_forever()

Starts the network loop and blocks the main thread, continuously running the loop to process MQTT messages.

The loop will run indefinitely unless the connection is lost or the program is terminated.

classmethod save_to_json()

Create class configuration file, if the file does not exist yet.

serialize_to_json(f)

Serialize.

classmethod set_log(l)

Set logger.

Parameters:

l (logger) – logger object

Return type:

None

shutdown()

Shut down all services, free resources, stop threads, disconnect from mqtt, in general, prepare for shutdown.

subscribe(topic)

Subscribe to the given MQTT topic.

This method sets up the subscription to the specified MQTT topic and registers the on_message() method as the callback for incoming messages.

Parameters:

topic (str) – The MQTT topic to subscribe to.

Return type:

None

Example:

# configure
obj.subscribe('foo/bar')
timestamp()

Returns the current date-time in UTC.

Returns:

datetime in UTC.

Return type:

rc (datetime)

timestampstr(ts)

Converts the given timestamp to human readable string of form ‘Y-m-d H:M:S’.

Parameters:

ts (timestamp) – time stamp to be converted

Returns:

human readable date-time string

Return type:

rc (string)

to_dict()

Convert instance attributes to a dictionary.

warning(msg, details='')

Logs the given warning message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

write(point)

Writes the given measurement to the database. In case of an error, it tries again until the maximum number of attempts is reached. If it is still unsuccessful, it gives up and passes the first encountered exception to the caller.

Parameters:

point – a measurement describing a time stamp and related attributes for one measurement.

write_attempts = 3
class juham.ts.PowerRecord(name='powerrecord')[source]

Bases: Base

Power utilization record.

This class listens the power utilization message and writes the state to time series database.

app_name = 'juham'
classmethod classattrs_from_dict(attributes)

Set class attributes from a dictionary.

classmethod classattrs_to_dict()

Convert class attributes to a dictionary.

config_folder = 'config'
copy()

Create and return a copy of the current object.

This method serializes the current object to a dictionary using the to_dict method, creates a new instance of the object’s class, and populates it with the serialized data using the from_dict method.

This method uses class identifier based instantiation (see factory method pattern) to create a new instance of the object, and ‘to_dict’ and ‘from_dict’ methods to initialize object’s state.

Returns:

A new instance of the object’s class with the same state as the original object.

Example:

john = Human("john")
john.height = 1.8
john.age = 62
clone_of_john = john.copy()
database_class_id: str | None = 0
database_client: object | None
debug(msg, details='')

Logs the given debug message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

deserialize_from_json(f)

Load attributes from a JSON file.

epoc2utc(epoch)

Converts the given epoch time to UTC time string. All time coordinates are represented in UTC time. This allows the time coordinate to be mapped to any local time representation without ambiguity.

Parameters:

  • epoch (float) – timestamp in UTC time

  • rc (str) – time string describing date, time and time zone e.g 2024-07-08T12:10:22Z

Returns:

UTC time

error(msg, details='')

Logs the given error message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

classmethod find_class(class_id)

Given class identifier find the registered class. If no class with the give identifier exists return None.

Parameters:

class_id (int) – class identifier

Returns:

class or null if not registered

Return type:

obj (obj)

from_dict(data)

Update instance attributes from a dictionary.

classmethod get_class_id()

Return the class id of the class. Each class has an unique identifier that can be used for instantiating the class via Object.instantiate() method.

Parameters:

cls (class) – class

Return type:

str

Returns:

id (int) unique class identifier through which the class can be instantiated by factory method pattern.

classmethod get_json_file()

Generate the JSON file name based on the class name.

The file is created into users home folder.

info(msg, details='')

Logs the given information message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

Example:

obj = new Base('test')
obj.info('Message arrived', str(msg))
init_database(name)

Instantiates the configured time series database object.

Issues a warning if the database_class_id has not been configured, in which case the object will not have the time series recording feature.

This method is called internally and typically there is no need to call it from the application code.

Return type:

None

init_mqtt(name)

Instantiates the configured MQTT object for networking.

This method is called internally and typically there is no need to call it from the application code.

Issues a warning if the pubsub_class_id has not been configured, even though objects without a capability to communicate are rather crippled.

Return type:

None

classmethod initialize_class()

Initialize the class for instantiation, if not initialized already. This method initializes the class identifier and deserializes the public attributes from the specified configuration folder.

Returns:

returns true if the class was initialized, false implies the class is already initialized in which case the method call has no effect.

Return type:

bool

classmethod instantiate(class_id)

Given class identifier create the corresponding object. This method implements so called factory method pattern.

Parameters:

class_id (int) – class identifier

Returns:

instance of the given class.

Return type:

obj (obj)

classmethod instantiate_with_param(class_id, param)

Given class identifier and one constructor argument create the corresponding object.

Parameters:

  • class_id (str | None) – class identifier

  • param (Any) – class specific constructor parameter

Returns:

instance of the given class.

Return type:

obj

classmethod is_abstract()

Check whether the class is abstract or real. Override in the derived sub-classes. The default is False.

Return type:

bool

Returns:

True (bool) if abstract

is_time_between(begin_time, end_time, check_time=None)

Check if the given time is within the given time line. All timestamps must be in UTC time.

Parameters:

  • begin_time (timestamp) – beginning of the timeline

  • end_time (timestamp) – end of the timeline

  • check_time (timestamp) – time to be checked

Returns:

True if within the timeline

Return type:

rc (bool)

classmethod load_from_json()

Load class attributes from a JSON file.

log_message(type, msg, details='')

Publish the given log message to the MQTT ‘log’ topic.

This method constructs a log message with a timestamp, class type, source name, message, and optional details. It then publishes this message to the ‘log’ topic using the MQTT protocol.

Parameters:

  • type – str The classification or type of the log message (e.g., ‘Error’, ‘Info’).

  • msg – str The main log message to be published.

  • details – str, optional Additional details about the log message (default is an empty string).

Returns:

None

Raises:

Exception – If there is an issue with the MQTT client while publishing the message.

Example:

# publish info message to the Juham's 'log' topic
self.log_message("Info", f"Some cool message {some_stuff}", str(dict))
mqtt_class_id: str | None = None
mqtt_host: str = 'localhost'
mqtt_port: int = 1883
mqtt_root_topic: str = 'juham'
on_connect(client, userdata, flags, rc)[source]

Standard mqtt connect notification.

This method is called when the client connection with the MQTT broker is established.

on_disconnect(client, userdata, rc=0)

Notification on disconnect.

This method is called whenever the MQTT broker is disconnected. For more information on this method consult MQTT documentation available in many public sources.

Parameters:

  • client (obj) – MQTT client

  • userdata (Any) – application specific data

  • rc (int) – See MQTT docs

on_message(client, userdata, msg)[source]

Standard mqtt message notification method.

This method is called upon new arrived message.

classmethod parse_args()

Parse the startup arguments defined by this class.

Return type:

None

pubsub_class_id = 0
read(point)

Reads the given measurement from the database.

Parameters:

point – point with initialized time stamp.

… note: NOT IMPLEMENTED YET

classmethod register()[source]

Register the class to the class database.

Once registered the class can be instantiated by its class identifier. Note that this method is called automatically by the system when the python loads the class. In this method sub classes should prepare themselves for instantiation by initializing their class attributes, for example.

classmethod register_class(class_id, ctor)

Register the given class identifier for identifier based instantiation . This, factory method pattern, as it is called, decouples the actual implementation from the interface. For more information see instantiate() method.

Parameters:

  • class_id (str) – class identifier

  • ctor (function) – constructor

run()

Start a new thread to runs the network loop in the background.

Allows the main program to continue executing while the MQTT client handles incoming and outgoing messages in the background.

run_forever()

Starts the network loop and blocks the main thread, continuously running the loop to process MQTT messages.

The loop will run indefinitely unless the connection is lost or the program is terminated.

classmethod save_to_json()

Create class configuration file, if the file does not exist yet.

serialize_to_json(f)

Serialize.

classmethod set_log(l)

Set logger.

Parameters:

l (logger) – logger object

Return type:

None

shutdown()

Shut down all services, free resources, stop threads, disconnect from mqtt, in general, prepare for shutdown.

subscribe(topic)

Subscribe to the given MQTT topic.

This method sets up the subscription to the specified MQTT topic and registers the on_message() method as the callback for incoming messages.

Parameters:

topic (str) – The MQTT topic to subscribe to.

Return type:

None

Example:

# configure
obj.subscribe('foo/bar')
timestamp()

Returns the current date-time in UTC.

Returns:

datetime in UTC.

Return type:

rc (datetime)

timestampstr(ts)

Converts the given timestamp to human readable string of form ‘Y-m-d H:M:S’.

Parameters:

ts (timestamp) – time stamp to be converted

Returns:

human readable date-time string

Return type:

rc (string)

to_dict()

Convert instance attributes to a dictionary.

warning(msg, details='')

Logs the given warning message to the database after logging it using the BaseClass’s info() method.

Parameters:

  • msg (str) – The information message to be logged.

  • details (str) – Additional detailed information for the message to be logged

write(point)

Writes the given measurement to the database. In case of an error, it tries again until the maximum number of attempts is reached. If it is still unsuccessful, it gives up and passes the first encountered exception to the caller.

Parameters:

point – a measurement describing a time stamp and related attributes for one measurement.

write_attempts = 3