-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Open temporary anonymous Linux file handles
--   
--   memfd lets us open memory-only files that are not linked into a
--   directory and are not backed by persistent storage. This feature is
--   only available on Linux.
@package memfd
@version 1.0.1.2


-- | This module is a small FFI wrapper around the <tt>memfd_create</tt> C
--   system call. Some documentation in this package is copied/paraphrased
--   from the Linux Programmer's Manual. Run "man 2 memfd_create" to see
--   the full documentation.
module Memfd

-- | Creates an anonymous file
--   
--   The file behaves like a regular file, and so can be modified,
--   truncated, memory-mapped, and so on. However, unlike a regular file,
--   it lives in RAM and has a volatile backing storage. Once all
--   references to the file are dropped, it is automatically released.
create :: CreateOptions -> IO Fd

-- | Default options for <a>create</a>, corresponding to what you get what
--   you use the C library and don't set any flags
--   
--   <ul>
--   <li><a>onExec</a> = <a>RemainOpenOnExec</a></li>
--   <li><a>sealing</a> = <a>DoNotAllowSealing</a></li>
--   <li><a>fileSystem</a> = <a>TemporaryFileSystem</a></li>
--   </ul>
defaultCreateOptions :: Name -> CreateOptions

-- | The name of an anonymous file
--   
--   The name is used as a filename and will be displayed as the target of
--   the corresponding symbolic link in the directory
--   <tt>/proc/self/fd/</tt>. The displayed name is always prefixed with
--   "memfd:" and serves only for debugging purposes. Names do not affect
--   the behavior of the file descriptor, and as such multiple files can
--   have the same name without any side effects.
newtype Name
NameString :: String -> Name
[nameString] :: Name -> String
data CreateOptions
CreateOptions :: Name -> OnExec -> Sealing -> FileSystem -> CreateOptions
[name] :: CreateOptions -> Name
[onExec] :: CreateOptions -> OnExec
[sealing] :: CreateOptions -> Sealing
[fileSystem] :: CreateOptions -> FileSystem
data OnExec

-- | The file descriptor will automatically be closed during a successful
--   execve
CloseOnExec :: OnExec
RemainOpenOnExec :: OnExec
data Sealing

-- | File seals can be applied to the file descriptor
AllowSealing :: Sealing
DoNotAllowSealing :: Sealing
data FileSystem
TemporaryFileSystem :: FileSystem
HugeTLBFileSystem :: HugeTLBOptions -> FileSystem

-- | Not every <a>HugeTLBSize</a> may be available on your platform. If you
--   select an unsupported page size, the system default page size will be
--   used instead. See <a>supportedHugeTLBSizes</a>.
data HugeTLBOptions

-- | Use the system default hugetlb page size
DefaultHugeTLB :: HugeTLBOptions

-- | Prefer the given hugetlb page size
HugeTLBSize :: HugeTLBSize -> HugeTLBOptions

-- | These sizes may not all be available on your platform. See
--   <a>supportedHugeTLBSizes</a>.
data HugeTLBSize
HugeTLB_64KB :: HugeTLBSize
HugeTLB_512KB :: HugeTLBSize
HugeTLB_1MB :: HugeTLBSize
HugeTLB_2MB :: HugeTLBSize
HugeTLB_8MB :: HugeTLBSize
HugeTLB_16MB :: HugeTLBSize
HugeTLB_32MB :: HugeTLBSize
HugeTLB_256MB :: HugeTLBSize
HugeTLB_512MB :: HugeTLBSize
HugeTLB_1GB :: HugeTLBSize
HugeTLB_2GB :: HugeTLBSize
HugeTLB_16GB :: HugeTLBSize

-- | List of hugetlb sizes that are supported by your platform
supportedHugeTLBSizes :: [HugeTLBSize]