Class: Imap::Backup::Lockfile

Inherits:
Object
  • Object
show all
Defined in:
lib/imap/backup/lockfile.rb

Defined Under Namespace

Classes: LockfileExistsError, ProcessStartTimeUnavailableError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path:) ⇒ Lockfile

Initializes a new Lockfile instance.



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# File 'lib/imap/backup/lockfile.rb', line 16

def initialize(path:)
  @path = path
end

Instance Attribute Details

#path ⇒ Object (readonly)

Returns the value of attribute path.



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# File 'lib/imap/backup/lockfile.rb', line 12

def path
  @path
end

Instance Method Details

#exists? ⇒ Boolean

Checks if the lockfile exists.



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# File 'lib/imap/backup/lockfile.rb', line 35

def exists?
  File.exist?(path)
end

#remove ⇒ Object

Removes the lockfile.



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# File 'lib/imap/backup/lockfile.rb', line 40

def remove
  FileUtils.rm_f(path)
end

#stale? ⇒ Boolean

Checks if the lockfile is stale (i.e., the process that created it is no longer running).



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# File 'lib/imap/backup/lockfile.rb', line 46

def stale?
  return false if !exists?

  file_content = File.read(path)
  data = JSON.parse(file_content, symbolize_names: true)
  pid = data[:pid]
  starttime = data[:starttime]
  proc_table_entry = Sys::ProcTable.ps(pid: pid)

  return true if proc_table_entry.nil?

  other_starttime = starttime(proc_table_entry)

  other_starttime != starttime
end

#with_lock(&block) ⇒ Object

Creates the lockfile, yields to the given block and ensures the lockfile is removed afterwards.

Raises:



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# File 'lib/imap/backup/lockfile.rb', line 22

def with_lock(&block)
  raise LockfileExistsError, "Lockfile already exists at #{path}" if exists?

  begin
    create
    block.call
  ensure
    remove
  end
end