Version1¶
Warning
This version is deprecated. It describes an older version of the library, which is no longer in use. This page is only kept for development purposes, and will be removed shortly.
Note
The code for this version is located in /poc1
Description¶
Demonstrator for the new Python binding. Main features are (once finsihed): - Full feature set (all functionalities of the underlying DDS library available) - Able to handle idl files properly (the atolab implementation converts everything to a string, and disregards idl files). - Pythonic implementation, to ensure the easy of use for developers.
Currently there is a minimal version available. It is possible to send and receive basic messages, using the json method. IDL support will be added in the near future.
Assumptions¶
The following library files need to be in the stated directory:
- libddsc.so at “/usr/local/lib”
- libddstubs.so at “/usr/local/lib”
The latter is the one coming from the atolab implementation, and is only needed temporarily. It contains the topic descriptor for the json topic. Once IDL support is added it will be removed.
![@startuml
class Participant {
ID: int
}
class Topic {
name: str
participant: Participant
ID: int
}
class Writer {
participant: Participant
topic: Topic
ID: int
--
__init__(Participant, Topic)
__call__(message)
}
class Listener {
ID: int
}
class Reader {
participant: Participant
topic: Topic
listener: Listener
ID: int
buffer: [void]
ivec: [SampleInfo]
size: int
---
__call__(as_type:type=None)
}
Topic o-- Participant
Writer o-- Participant
Writer o-- Topic
Reader o-- Participant
Reader o-- Topic
Reader o-- Listener
@enduml](../../../_images/plantuml-ae5086745f41f35e7723d6a76abfbd2cda1ce0f8.png)
Examples¶
The files sender.py and receiver.py demonstrate the usage of the library. Sender publishes a simple message to the topic “testtopic” every 2 seconds, and logs it to the console.
Receiver reads the same topic, once every 3 seconds, and logs the list of read messages to the console. (It always reads a list of messages, so reading more than one at a time is not a problem.)
The files can be called from the Examples folder as follows:
python3 sender.py
and
python3 receiver.py