Support openTempFile and friends, fixes #2

[hasufell]

Also see: haskell/directory#182

TODO:

• windows

@Rufflewind

[Bodigrim]

LGTM, no idea what’s up with Windows CI job though.

[hasufell]

LGTM, no idea what’s up with Windows CI job though.

It's suspicious. It also seems to be flaky.

[hasufell]

@Rufflewind @Mistuke

Any idea why these concurrency tests would sometimes fail on windows?

https://github.com/hasufell/file-io/blob/a4a0464ccd38e8380c202949a90b21d9e592aeef/tests/Properties.hs#L109-L137

I can not reproduce in my windows VM.

[Rufflewind]

_ <- OSP.openFile fp ReadMode

Is this intended to create a dangling handle? Genreally I would be a bit wary of writing a standalone statement in a garbage-collected language since there may or may not be a finalizer that releases the handle automatically if it goes unused.

Maybe someone familiar with the implementation details of hANDLEToHandle has a better idea of what's going on.

[Bodigrim]

Yeah, it might be worth to try something like

     !h <- OSP.openFile fp ReadMode 
     r <- try @IOException $ OSP.withFile fp WriteMode $ \h' -> do BS.hPut h' "test" 
     BS.hPut h "should have failed before"

[Mistuke]

_ <- OSP.openFile fp ReadMode

Is this intended to create a dangling handle? Genreally I would be a bit wary of writing a standalone statement in a garbage-collected language since there may or may not be a finalizer that releases the handle automatically if it goes unused.

Maybe someone familiar with the implementation details of hANDLEToHandle has a better idea of what's going on.

We always add a finalizer to any handle you create. But the intention there is usually to make sure we don't leak resources. The RTS will invoke all finalizers before terminating. But when the finalizer run is non-deterministic. We only guarantee that it will run by the time you shutdown.

I think @Bodigrim 's solution is correct for the tests that check if the file is locked, and for the ones that check if you can read it you need >>= hClose.

[hasufell]

This is released as file-io-0.1.3.