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Added link layer "tags". Tags add filter criteria to individual queues for restricting/allowing traffic during certain slots

Eric Gallimore requested to merge dev/link_layer_tags into devel
  • Significant refactoring of message_queue_node.py. Added a ton of comments in-line.

Breaking Changes

  • Changes to the following message types:
    • TdmaStatus.msg, TdmaAdvancedStatus.msg, TdmaScriptedStatus.msg, TdmaSlottedAlohaStatus.msg:
      • added require_tags: str[]
      • added exclude_tags: str[]

New Features / Improvements

  • New feature added called "tags".
    • all TDMA MAC types support tags. For TDMA, the tags are associated with a slot. The rosparam is: ~slot_tags.
    • message_queue_node now supports tags:
      • on link layer queues and dynamic queues.
      • added Optional tag attr to QueueParams dataclass (list of strings).

Bugfixes

  • message_queue_node:
    • fixed bug in query_dynamic_queues. Now checks if dest_address is None
    • now check that the highest priority packet codec can fit in the available space with the overhead

Notes:

We have created a tool called "tags". Tags are used for adding context to individual queues that can then be used for filtering while building a packet. The TDMA MAC uses tags slightly differently. Rather than a list of tags, TDMA creates a ~slot_tags structure which associates require_tags and/or exclude_tags (also includes optional minimum_priority) with a specific slot or range of slots. When TDMA is ready to build a packet for transmit, it will pass the tag information for the current slot to message_queue in the call to get_next_packet_data().

When TDMA makes the call to get_next_packet_data() it includes the set of require_tags and exclude_tags for THIS slot. For message_queue these are the setting it will use for the packet it returns from get_next_packet_data().

Tags are supported in dynamic_queues. The difference is, we don't manage those queues directly so we pass the tags information in the dynamic_queue query call for the client to manage directly.

Our current MAC type is TDMA but, this paradigm could be expanded to fit MACs other than TDMA. The service endpoints defined in GetNextPacketData.srv and GetNextQueuedMessage.srv defines the API for using tags.

How tag exclusion criteria works:

queue excluded has tag in require_tags has tag in exclude_tags
True True True
True False True
False ** False False
False True False

** Would be: True if there were require_tags this slot.

MAC Configuration:

Example of a ~slot_tags configuration:

slot_tags:
  - slots: 0-11           # settings for slots 0-11 (no tags in this one, just priority)
    minimum_priority: 10  # ** this minimum_priority will be overwritten in tagged slots below this one
  - slots: 2              # this is a set of tags for slot 2 (tags that cover slot ranges will be combined)
    minimum_priority: 50  # this will set the minimum priority for this slot (this will overwrite minimum_priority: 10 set ^^)
    exclude_tags:         # any queues with these tag(s) will not be transmitted in this slot
      - 'low_priority' 
      - 'images'
  - slots: 4-11        # this set of slot tags will be used for slots 4-11
    require_tags:      # any queues with these tag(s) WILL be transmitted in this slot (IF they don't have any on exclude list)
      - 'chat'         
  - slots: 4-11:2      # this set of slot tags will be used for slots 4-11:2 == (4,6,8,10)
    exclude_tags:      # any queues with these tag(s) will not be transmitted in this slot
      - 'images'
  - slots: 4,6,7       # this set of slot tags will be used for slots 4,6,7
    require_tags:      # any queues with these tag(s) WILL be transmitted in this slot (IF they don't have any on exclude list)
      - 'some_aloha'   
    exclude_tags:      # any queues with these tag(s) will not be transmitted in this slot
      - 'images'

Codec Configuration:

Example of tags defined for a specific queue in a codec yaml:

    - id: 100
      message_codec: default
      subscribe_topic: "chat_msgs"
      publish_topic: "from_acomms"
      ros_type: "std_msgs/Int8"
      default_dest: 121
      queue_order: fifo
      queue_maxsize: 10
      priority: 50
      tags:
        - 'chat'
      fields:
        data:
          codec: int8
    - id: 101
      message_codec: default
      subscribe_topic: "chat_images"
      publish_topic: "from_acomms"
      ros_type: "std_msgs/Int8"
      default_dest: 121
      queue_order: fifo
      queue_maxsize: 10
      priority: 50
      tags:
        - 'chat'
        - 'images'
      fields:
        data:
          codec: int8
    - id: 102
      message_codec: default
      subscribe_topic: "low_priority"
      publish_topic: "from_acomms"
      ros_type: "std_msgs/Int8"
      default_dest: 121
      queue_order: fifo
      queue_maxsize: 10
      priority: 50
      tags:
        - 'low_priority'
      fields:
        data:
          codec: int8
Edited by Caileigh Fitzgerald

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