brew/Library/Homebrew/lock_file.rb
Issy Long 45978435e7
rubocop: Use Sorbet/StrictSigil as it's better than comments
- Previously I thought that comments were fine to discourage people from
  wasting their time trying to bump things that used `undef` that Sorbet
  didn't support. But RuboCop is better at this since it'll complain if
  the comments are unnecessary.

- Suggested in https://github.com/Homebrew/brew/pull/18018#issuecomment-2283369501.

- I've gone for a mixture of `rubocop:disable` for the files that can't
  be `typed: strict` (use of undef, required before everything else, etc)
  and `rubocop:todo` for everything else that should be tried to make
  strictly typed. There's no functional difference between the two as
  `rubocop:todo` is `rubocop:disable` with a different name.

- And I entirely disabled the cop for the docs/ directory since
  `typed: strict` isn't going to gain us anything for some Markdown
  linting config files.

- This means that now it's easier to track what needs to be done rather
  than relying on checklists of files in our big Sorbet issue:

```shell
$ git grep 'typed: true # rubocop:todo Sorbet/StrictSigil' | wc -l
    268
```

- And this is confirmed working for new files:

```shell
$ git status
On branch use-rubocop-for-sorbet-strict-sigils
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        Library/Homebrew/bad.rb
        Library/Homebrew/good.rb

nothing added to commit but untracked files present (use "git add" to track)

$ brew style
Offenses:

bad.rb:1:1: C: Sorbet/StrictSigil: Sorbet sigil should be at least strict got true.
^^^^^^^^^^^^^

1340 files inspected, 1 offense detected
```
2024-08-12 15:24:27 +01:00

77 lines
1.7 KiB
Ruby

# typed: true # rubocop:todo Sorbet/StrictSigil
# frozen_string_literal: true
require "fcntl"
# A lock file to prevent multiple Homebrew processes from modifying the same path.
class LockFile
attr_reader :path
sig { params(type: Symbol, locked_path: Pathname).void }
def initialize(type, locked_path)
@locked_path = locked_path
lock_name = locked_path.basename.to_s
@path = HOMEBREW_LOCKS/"#{lock_name}.#{type}.lock"
@lockfile = nil
end
def lock
@path.parent.mkpath
create_lockfile
return if @lockfile.flock(File::LOCK_EX | File::LOCK_NB)
raise OperationInProgressError, @locked_path
end
def unlock
return if @lockfile.nil? || @lockfile.closed?
@lockfile.flock(File::LOCK_UN)
@lockfile.close
end
def with_lock
lock
yield
ensure
unlock
end
private
def create_lockfile
return if @lockfile.present? && !@lockfile.closed?
begin
@lockfile = @path.open(File::RDWR | File::CREAT)
rescue Errno::EMFILE
odie "The maximum number of open files on this system has been reached. Use `ulimit -n` to increase this limit."
end
@lockfile.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
end
end
# A lock file for a formula.
class FormulaLock < LockFile
sig { params(rack_name: String).void }
def initialize(rack_name)
super(:formula, HOMEBREW_CELLAR/rack_name)
end
end
# A lock file for a cask.
class CaskLock < LockFile
sig { params(cask_token: String).void }
def initialize(cask_token)
super(:cask, HOMEBREW_PREFIX/"Caskroom/#{cask_token}")
end
end
# A lock file for a download.
class DownloadLock < LockFile
sig { params(download_path: Pathname).void }
def initialize(download_path)
super(:download, download_path)
end
end