lukko

File locking

Version on this page:	0.1.1.3@rev:3
LTS Haskell 20.15:	0.1.1.3@rev:3
Stackage Nightly 2023-03-20:	0.1.1.3@rev:3
Latest on Hackage:	0.1.1.3@rev:4

See all snapshots lukko appears in

GPL-2.0-or-later AND BSD-3-Clause licensed

Maintained by Oleg Grenrus

This version can be pinned in stack with:lukko-0.1.1.3@sha256:efd4c08c4df1ac3f423858a834c0e3b5b4909febda66a901d12a8e1d57bddaa8,4570

Module documentation for 0.1.1.3

Lukko
- Lukko.NoOp

Depends on 1 package(full list with versions):

base

Used by 2 packages in lts-20.9(full list with versions):

cabal-install, hackage-security

This package provides access to platform dependent file locking APIs:

Open file descriptor locking on Linux (Lukko.OFD)
BSD-style flock(2) locks on UNIX platforms (Lukko.FLock)
Windows locking via LockFileEx (Lukko.Windows)
No-op locking, which throws exceptions (Lukko.NoOp)
Lukko module exports the best option for the target platform with uniform API.

There are alternative file locking packages:

GHC.IO.Handle.Lock in base >= 4.10 is good enough for most use cases. However, uses only Handles so these locks cannot be used for intra-process locking. (You should use e.g. MVar in addition).
filelock doesn't support OFD locking.

Lukko means lock in Finnish.

Submodules Lukko.OFD, Lukko.Windows etc are available based on following conditions.

if os(windows)
  cpp-options: -DHAS_WINDOWS_LOCK

elif (os(linux) && flag(ofd-locking))
  cpp-options: -DHAS_OFD_LOCKING
  cpp-options: -DHAS_FLOCK

elif !(os(solaris) || os(aix))
  cpp-options: -DHAS_FLOCK

Lukko.FLock is available on not (Windows or Solaris or AIX). Lukko.NoOp is always available.

Changes

0.1.1.3

Use CApiFFI to call varargs C functions.
Define let alignment only when needed.

0.1.1.2

Make Win32 code more idiomatic

0.1.1.1

Add proper Setup.hs

0.1.1

Add Setup.hs to sdist
Add type-level FileLockingSupported