Add the possibility to use spdlog with YARP

[GiulioRomualdi]

This PR closes #407. In detail, I implemented a custom sink to handle the logging through yarp.

The switching between the normal logging to the yarp one is pretty simple and has been implemented using the factory pattern.

#include <BipedalLocomotion/TextLogging/Logger.h>
#include <BipedalLocomotion/TextLogging/YarpLogger.h>
#include <BipedalLocomotion/TextLogging/LoggerBuilder.h>
// Change the logger
BipedalLocomotion::TextLogging::LoggerBuilder::setFactory(std::make_shared<BipedalLocomotion::TextLogging::YarpLoggerFactory>()));

BipedalLocomotion::log()->info("My info");

will print

[INFO] [2021-09-02 23:20:43.501] [thread: 108475] [blf] My info

using yInfo()

Thanks to this feature all the applications that uses BipedalLocomotion::log can log all the info/errors in a yarp logger

[diegoferigo]

Disclaimer: I didn't review the files yet.

Does this implementation change the logger in a process-wise manner? And I mean, if there are multiple systems (advanceables) running, but just one in its compile unit switches the logger to YARP, do all the logging -also of the other systems- be sunk to the new logger?

[GiulioRomualdi]

Does this implementation change the logger in a process-wise manner?

Since the logger is treated as a singleton the builder should be called before calling the first time log() (i.e. at the beginning of your main).

Then all the treads spawned by that application will use yarp to log

[diegoferigo]

Ok, I guess that this operation will be done in the main() and then the entire application will dump to the right sink 👍

[traversaro]

Ok, I guess that this operation will be done in the main() and then the entire application will dump to the right sink 👍

Yes, I think that's the idea in general with spdlog loggers, at least the one provided by singletons .

[diegoferigo]

Yep, this morning for some reason I was assuming this to be done in the Advanceable's code. But that makes no sense, hence I asked. From the main is definitely the intended pattern.