brew/Library/Homebrew/lock_file.rb
2024-11-24 00:03:31 +01:00

90 lines
2.0 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
sig { void }
def lock
ignore_interrupts do
create_lockfile
next if @lockfile.flock(File::LOCK_EX | File::LOCK_NB)
raise OperationInProgressError, @locked_path
end
end
sig { params(unlink: T::Boolean).void }
def unlock(unlink: false)
ignore_interrupts do
next if @lockfile.nil? || @lockfile.closed?
@lockfile.flock(File::LOCK_UN)
@lockfile.close
if unlink
@path.unlink if @path.exist?
@lockfile = nil
end
end
end
def with_lock
lock
yield
ensure
unlock
end
private
def create_lockfile
return if @lockfile.present? && !@lockfile.closed?
@path.dirname.mkpath
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