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


-- | Automatically spin up and spin down local daemons
--   
--   Gargoyle is a framework for managing daemons from Haskell. In the
--   current release the only requirement is that the daemon be able to
--   communicate over a Unix domain socket. See <a>gargoyle-postgresql</a>
--   for a fully worked out example.
--   
--   To use Gargoyle the client must:
--   
--   <ol>
--   <li>Define a value of the <a>Gargoyle</a> type which specifies how to
--   administer the daemon.</li>
--   <li>Create an executable whose <a>main</a> is <a>gargoyleMain</a>. The
--   name of this executable should match the executable name specified in
--   the <a>_gargoyle_exec</a> field of the <a>Gargoyle</a>.</li>
--   <li>The client will run their code with <a>withGargoyle</a> to gain
--   access to the daemon.</li>
--   </ol>
@package gargoyle
@version 0.1


-- | Utilities for running a daemon in a local directory
module Gargoyle
data Gargoyle pid a
Gargoyle :: FilePath -> (FilePath -> IO ()) -> (FilePath -> IO pid) -> (pid -> IO ()) -> (FilePath -> IO a) -> Gargoyle pid a

-- | The path to the executable created with <a>gargoyleMain</a> which will
--   serve as the daemon monitor process.
[_gargoyle_exec] :: Gargoyle pid a -> FilePath

-- | The action to run in order to populate the daemon's environment for
--   the first run.
[_gargoyle_init] :: Gargoyle pid a -> FilePath -> IO ()

-- | The action to run in order to spin up the daemon on every run. This
--   happens after <a>_gargoyle_init</a> if it also runs.
[_gargoyle_start] :: Gargoyle pid a -> FilePath -> IO pid

-- | The action to run when the monitor process detects that no clients are
--   connected anymore.
[_gargoyle_stop] :: Gargoyle pid a -> pid -> IO ()

-- | Run a command which knows about the working directory of the daemon to
--   collect runtime information to pass to client code in
--   <a>withGargoyle</a>.
[_gargoyle_getInfo] :: Gargoyle pid a -> FilePath -> IO a

-- | Run an IO action while maintaining a connection to a daemon. The
--   daemon will automatically be stopped when no clients remain. If the
--   daemon has not yet been initialized, it will be. The counterpart of
--   this function is <a>gargoyleMain</a> which should be used to produce
--   an executable that will monitor the daemon's status.
withGargoyle :: Gargoyle pid a -> FilePath -> (a -> IO b) -> IO b

-- | Run a local daemon over a domain socket; the daemon will be
--   automatically stopped when no clients remain. This function assumes
--   that the daemon has already been initialized in the specified
--   location. This function should be used as the main function of an
--   executable which will then be invoked by calling <a>withGargoyle</a>
--   in the client code to monitor the daemon's status.
gargoyleMain :: Gargoyle pid a -> IO ()