Interacting with Queue Server

Subscribing to Published Console Output

If console output publishing is enabled at RE Manager (parameter --zmq-publish-console), the output is published to 0MQ socket. Client applications may subscribe to the messages and use them for processing, display them to users or forward to other applications.

The messages are published to a PUB 0MQ socket running. Multiple applications may subscribe to the socket simultaneously. The clients must be subscribed to the socket to receive the messages. The messages are not delivered to the client if they are published while the client is not subscribed to the socket. The messages are published using the topic named QS_Console.

Each message contains timestamped string printed by RE Manager. Some strings can be empty or contain multiple lines. Messages are python JSON-represented dictionaries with the following format:

{"time": <timestamp>, "msg": <message>}

<timestamp> is floating point number (returned by time.time()) and <message> is a string.

The bluesky-queueserver package provides convenience API class (ReceiveConsoleOutput) for use in synchronous or thread-based applications. The class provides subscribe() and unsubscribe() methods that enable caching of published messages by 0MQ and blocking recv() method (with timeout) for loading published messages. See the class documentation for detailed description of the methods and code examples.

`ReceiveConsoleOutput`	The class defaults are set to receive 0MQ messages with console output.
`ReceiveConsoleOutput.subscribe`	Subscribe 0MQ socket to the topic.
`ReceiveConsoleOutput.unsubscribe`	Unsubscribe 0MQ socket from the topic.
`ReceiveConsoleOutput.recv`	Get the next published message.

Asyncio-based applications (e.g. HTTP server) may use ReceiveConsoleOutputAsync API class to receive captured console output. The class provides subscribe() and unsubscribe() methods to explicitly subscribe and unsubscribe 0MQ socket. The class may be used in two modes: polling using recv() method or setting callback function or coroutine with set_callback() method and starting and then stopping acquisition with start() and stop() methods.

`ReceiveConsoleOutputAsync`	The class defaults are set to receive 0MQ messages with console output.
`ReceiveConsoleOutputAsync.subscribe`	Subscribe 0MQ socket to the topic.
`ReceiveConsoleOutputAsync.unsubscribe`	Unsubscribe 0MQ socket from the topic.
`ReceiveConsoleOutputAsync.recv`	Get the next published message.
`ReceiveConsoleOutputAsync.set_callback`	Set callback function, which is called once for each received message.
`ReceiveConsoleOutputAsync.start`	Start collection of messages published by RE Manager.
`ReceiveConsoleOutputAsync.stop`	Stop collection of messages published by RE Manager.

Subscribing to Published System Info

In addition to streaming of console output, RE Manager is publishing status information to the same 0MQ PUB socket. The status information published using a different topic and can be easily separated from console output messages. The messages are published once per second or each time status is changed by RE Manager. Periodically published status can be used as ‘heartbeat’ to detect that RE Manager is running properly.

The message format used for streaming is similar to the message format for console output. The status key indicates that the message contains status information. Messages with other information may be added to the stream in the future:

{"time": <timestamp>, "msg": {"status": <status-info>}}

The ReceiveSystemInfo class can be used in synchronous or thread-based applications to receive the streamed messages:

`ReceiveSystemInfo`	The class defaults are set to receive 0MQ messages with system information.
`ReceiveSystemInfo.subscribe`	Subscribe 0MQ socket to the topic.
`ReceiveSystemInfo.unsubscribe`	Unsubscribe 0MQ socket from the topic.
`ReceiveSystemInfo.recv`	Get the next published message.

ReceiveSystemInfoAsync is the asyncio-based version of the class:

`ReceiveSystemInfoAsync`	The class defaults are set to receive 0MQ messages with system information.
`ReceiveSystemInfoAsync.subscribe`	Subscribe 0MQ socket to the topic.
`ReceiveSystemInfoAsync.unsubscribe`	Unsubscribe 0MQ socket from the topic.
`ReceiveSystemInfoAsync.recv`	Get the next published message.
`ReceiveSystemInfoAsync.set_callback`	Set callback function, which is called once for each received message.
`ReceiveSystemInfoAsync.start`	Start collection of messages published by RE Manager.
`ReceiveSystemInfoAsync.stop`	Stop collection of messages published by RE Manager.

Formatting Descriptions of Plans and Plan Parameters

format_text_descriptions function may be used to generate formatted text descriptions of plans and plan parameters. The formatted descriptions are intended to be displayed to users by client applications. See the docstring for the function for more details.

format_text_descriptions

Format parameter descriptions for a plan from the list of allowed plans.