Improve responsiveness on macos: add support for kFSEventStreamCreateFlagNoDefer

[iwelch]

hi enrico---in the docs, you probably want to change "OS X" to "macos" now.

even with a latency request of 0.2, fswatch sometimes takes several seconds. Other apps, liked Marked 2 (https://marked2app.com/) are always instant, using fsevents.

regards, /iaw

[emcrisostomo]

Thank you very much @iwelch: in fact fswatch doesn't allow you to specify the kFSEventStreamCreateFlagNoDefer flag (libfswatch does):

Here is the documentation and the rationale for the behaviour of fswatch is:

This is the default behavior and is more appropriate for background, daemon or batch processing apps.

I'm marking this as an enhancement.

[iwelch]

Suggestion: If fswatch is running on a tty, make fast check the update. if fswatch is invoked in batch, make slow check the update. (and maybe allow a flag to toggle.)

[emcrisostomo]

Thanks, that's a good suggestion indeed.

[emcrisostomo]

This has been implemented in master. Thanks @iwelch