Adding OSAL inotify

[MaciejKaszynski]

Adding a small wrapper around score::os::InotifyInstance to get iterator syntax.

Usage:

    auto instance = std::make_unique<score::os::InotifyInstanceImpl>();
    instance.AddWatch("/tmp", score::os::Inotify::EventMask::kInCreate);

    for (const score::os::InotifyEvent& event : INotifyRange{std::move(instance)})
    {
        // will block until a new event is present
        // running touch /tmp/test will print test!
        std::cout << event.GetName() << std::endl;
    };

[github-actions]

License Check Results

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bazel run --lockfile_mode=error //:license-check

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[License Check Output]
Extracting Bazel installation...
Starting local Bazel server (8.6.0) and connecting to it...
INFO: Invocation ID: f0d1cd6a-813c-4eee-96f8-e2a378148cb0
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Analyzing: target //:license-check (1 packages loaded, 0 targets configured)
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Analyzing: target //:license-check (35 packages loaded, 10 targets configured)

Analyzing: target //:license-check (89 packages loaded, 10 targets configured)

Analyzing: target //:license-check (136 packages loaded, 394 targets configured)

Analyzing: target //:license-check (157 packages loaded, 4090 targets configured)

Analyzing: target //:license-check (157 packages loaded, 7860 targets configured)

Analyzing: target //:license-check (160 packages loaded, 9344 targets configured)

Analyzing: target //:license-check (160 packages loaded, 9344 targets configured)

Analyzing: target //:license-check (170 packages loaded, 9397 targets configured)

Analyzing: target //:license-check (170 packages loaded, 9397 targets configured)

Analyzing: target //:license-check (173 packages loaded, 11285 targets configured)

Analyzing: target //:license-check (173 packages loaded, 11285 targets configured)

INFO: Analyzed target //:license-check (175 packages loaded, 11535 targets configured).
[1 / 12] Writing repo mapping manifest for //:license.check.license_check; 0s local ... (3 actions running)
[12 / 16] JavaToolchainCompileClasses external/rules_java+/toolchains/platformclasspath_classes; 0s disk-cache, processwrapper-sandbox ... (2 actions running)
[15 / 16] [Prepa] Building license.check.license_check.jar ()
INFO: Found 1 target...
Target //:license.check.license_check up-to-date:
  bazel-bin/license.check.license_check
  bazel-bin/license.check.license_check.jar
INFO: Elapsed time: 30.495s, Critical Path: 2.59s
INFO: 16 processes: 12 internal, 3 processwrapper-sandbox, 1 worker.
INFO: Build completed successfully, 16 total actions
INFO: Running command line: bazel-bin/license.check.license_check ./formatted.txt <args omitted>
usage: org.eclipse.dash.licenses.cli.Main [-batch <int>] [-cd <url>]
       [-confidence <int>] [-ef <url>] [-excludeSources <sources>] [-help] [-lic
       <url>] [-project <shortname>] [-repo <url>] [-review] [-summary <file>]
       [-timeout <seconds>] [-token <token>]

[github-actions]

The created documentation from the pull request is available at: docu-html

[paulquiring]

OSAL_INOTIFY_RANGE_HPP_INCLUDED

[SimonKozik]

Just a suggestion, shall we also include namespace in the #def?
SCORE_MW_LIFECYCLE_OSAL_INOTIFY_RANGE_HPP

[paulquiring]

Some findings nothing major.

[NicolasFussberger]

I am not sure I completely understand how this would be used.
It looks like you would still need to interact with the InotifyInstance to setup the file notification first.
And then later to call Close() but the pointer has already been moved to the INotifyRange

E.g. within some kind of FileWatchReadyCondition class:

std::unique_ptr<InotifyInstance> inotify = std::make_unique<InotifyInstanceImpl>();

// init
bool init() {
  if(!inotify->IsValid) {
    // ready condition failed
     return false;
  }
  
  if(!inotify->AddWatch(path, event_mask)) {
    // ready condition failed
    return false;
  }
}

// at runtime
score::cpp::expected_blank<Error> WaitForReadyCondition(stop_token) {
   INotifyRange range(std::move(inotify);
   while(!ready_timeout_over) {
       for(events : range) {  // does this block? How to interrupt this on timeout?
          // if the expected event occured -> return Success
          // else continue until timeout
       }
   }
}

// at destruction
// want to call inotify->Close() but its already moved out

[MaciejKaszynski]

I will add this to a FileHandler class that will work like OsHandler (seperate thread).

I will add a stop() method I think then this would be the code

FileHandler::run(){
    auto instance = std::make_unique<score::os::InotifyInstanceImpl>();
    instance.AddWatch("/tmp", score::os::Inotify::EventMask::kInCreate);
    range_ = INotifyRange{std::move(instance)}
    for (const score::os::InotifyEvent& event : range_)
    {
        std::cout << event.GetName() << std::endl;
    };
}

FileHandler::stop()
{
    range_.stop();
}

[NicolasFussberger]

As far as I understood, this Read() call blocks until there is an event.
How to interrupt this when the ready timeout is over?
Or the startup needs to be aborted?

[MaciejKaszynski]

InotifyInstance.Close() aborts this