File monitor

Simplified File Watching Interface

Use cases

• Watch for source code changes and rerun unit tests
  • Shell command, should be cancelable
  • Needs to be filterable (ie .go, .cpp, .hpp)
• Watch for kernel/nvidia driver changes and copy to EFI

Requirements

• Must support cancelable shell command.
• Functions/GoRoutines can't be canceled.
• Different editors have differnt save strategies.
• Most changes result in multiple events (touch for example CREAT+CHMOD).
• Should support a delay (could stop spamming changes).
• Delay should be reset each time a new action occurs.

Modification time? Might not help if you copy an old file onto a new one...

Example

file: /usr/lib/modules/linux.so
cancelable: yes
delay: 10ms
action: cp /usr/lib/modules/linux.so /boot/efi/blah.so

file: /src/program
cancelable: yes
delay: 10ms
action: go test ./...

file: /mnt/storage/large_files
cancelable: no
delay: 10ms
action: go func {SomeLongRunningAction()}

fsnotify event examples

touch a

2016/04/09 11:59:47 Event: "/home/hegemon/programming/ansible/a": CREATE
2016/04/09 11:59:47 Event: "/home/hegemon/programming/ansible/a": CHMOD

vim :wq

2016/04/09 12:00:19 Event: "/home/hegemon/programming/ansible/4913": CREATE
2016/04/09 12:00:19 Event: "/home/hegemon/programming/ansible/a": RENAME
2016/04/09 12:00:19 Event: "/home/hegemon/programming/ansible/a": CREATE
2016/04/09 12:00:19 Event: "/home/hegemon/programming/ansible/a": WRITE
2016/04/09 12:00:19 Event: "/home/hegemon/programming/ansible/a": CHMOD

atom (save existing file):

2016/04/09 13:32:59 Event: "/home/hegemon/programming/ansible/a": WRITE
2016/04/09 13:32:59 Event: "/home/hegemon/programming/ansible/a": WRITE

mv b a

2016/04/09 13:31:24 Event: "/home/hegemon/programming/ansible/b": RENAME
2016/04/09 13:31:24 Event: "/home/hegemon/programming/ansible/a": CREATE