67 lines
1.9 KiB
Haskell
67 lines
1.9 KiB
Haskell
-- | Development version to be run inside GHCi.
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--
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-- start this up with:
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--
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-- cabal repl --ghc-options="-O0 -fobject-code"
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--
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-- run with:
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--
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-- :l DevelMain
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-- DevelMain.update
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--
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-- You will need to add these packages to your .cabal file
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-- * foreign-store >= 0.1 (very light-weight)
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-- * warp (you already depend on this, it just isn't in your .cabal file)
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--
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-- If you don't use cabal repl, you will need
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-- to add settings to your .ghci file.
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--
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-- :set -DDEVELOPMENT
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--
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-- There is more information about using ghci
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-- on the wiki: https://github.com/yesodweb/yesod/wiki/ghci
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module DevelMain where
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import Application (getApplicationDev)
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import Control.Exception (finally)
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import Control.Concurrent
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import Data.IORef
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import Foreign.Store
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import Network.Wai.Handler.Warp
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-- | Start or restart the server.
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-- A Store holds onto some data across ghci reloads
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update :: IO ()
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update = do
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mtidStore <- lookupStore tidStoreNum
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case mtidStore of
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-- no server running
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Nothing -> do
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done <- storeAction doneStore newEmptyMVar
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tid <- start done
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_ <- storeAction (Store tidStoreNum) (newIORef tid)
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return ()
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-- server is already running
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Just tidStore ->
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-- shut the server down with killThread and wait for the done signal
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modifyStoredIORef tidStore $ \tid -> do
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killThread tid
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withStore doneStore takeMVar >> readStore doneStore >>= start
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where
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doneStore = Store 0
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tidStoreNum = 1
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modifyStoredIORef :: Store (IORef a) -> (a -> IO a) -> IO ()
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modifyStoredIORef store f = withStore store $ \ref -> do
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v <- readIORef ref
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f v >>= writeIORef ref
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-- | Start the server in a separate thread.
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start :: MVar () -- ^ Written to when the thread is killed.
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-> IO ThreadId
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start done = do
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(settings,app) <- getApplicationDev
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forkIO (finally (runSettings settings app)
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(putMVar done ()))
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