http-client-0.3.7.1: Network/HTTP/Client/Manager.hs
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE RankNTypes #-}
module Network.HTTP.Client.Manager
( ManagerSettings (..)
, newManager
, closeManager
, withManager
, getConn
, failedConnectionException
, defaultManagerSettings
) where
#if !MIN_VERSION_base(4,6,0)
import Prelude hiding (catch)
#endif
import Data.Monoid (mappend)
import System.IO (hClose, hFlush, IOMode(..))
import qualified Data.IORef as I
import qualified Data.Map as Map
import qualified Data.ByteString.Char8 as S8
import qualified Data.ByteString.Lazy as L
import qualified Blaze.ByteString.Builder as Blaze
import Data.Text (Text)
import qualified Data.Text as T
import Control.Monad.IO.Class (MonadIO, liftIO)
import Control.Monad (unless, join)
import Control.Exception (mask_, SomeException, bracket, catch, throwIO, fromException, mask, IOException, Exception (..), handle)
import Control.Concurrent (forkIO, threadDelay)
import Data.Time (UTCTime (..), Day (..), DiffTime, getCurrentTime, addUTCTime)
import Control.DeepSeq (deepseq)
import qualified Network.Socket as NS
import Data.Maybe (mapMaybe)
import System.IO (Handle)
import System.Mem.Weak (Weak, deRefWeak)
import Network.HTTP.Types (status200)
import Network.HTTP.Client.Types
import Network.HTTP.Client.Connection
import Network.HTTP.Client.Headers (parseStatusHeaders)
-- | Default value for @ManagerSettings@.
--
-- Since 0.1.0
defaultManagerSettings :: ManagerSettings
defaultManagerSettings = ManagerSettings
{ managerConnCount = 10
, managerRawConnection = return openSocketConnection
, managerTlsConnection = return $ \_ _ _ -> throwIO TlsNotSupported
, managerTlsProxyConnection = return $ \_ _ _ _ _ _ -> throwIO TlsNotSupported
, managerResponseTimeout = Just 30000000
, managerRetryableException = \e ->
case fromException e of
Just (_ :: IOException) -> True
_ ->
case fromException e of
-- Note: Some servers will timeout connections by accepting
-- the incoming packets for the new request, but closing
-- the connection as soon as we try to read. To make sure
-- we open a new connection under these circumstances, we
-- check for the NoResponseDataReceived exception.
Just NoResponseDataReceived -> True
Just IncompleteHeaders -> True
_ -> False
, managerWrapIOException =
let wrapper se =
case fromException se of
Just e -> toException $ InternalIOException e
Nothing -> se
in handle $ throwIO . wrapper
, managerIdleConnectionCount = 512
}
takeSocket :: Manager -> ConnKey -> IO (Maybe Connection)
takeSocket man key =
I.atomicModifyIORef (mConns man) go
where
go ManagerClosed = (ManagerClosed, Nothing)
go mcOrig@(ManagerOpen idleCount m) =
case Map.lookup key m of
Nothing -> (mcOrig, Nothing)
Just (One a _) ->
let mc = ManagerOpen (idleCount - 1) (Map.delete key m)
in mc `seq` (mc, Just a)
Just (Cons a _ _ rest) ->
let mc = ManagerOpen (idleCount - 1) (Map.insert key rest m)
in mc `seq` (mc, Just a)
putSocket :: Manager -> ConnKey -> Connection -> IO ()
putSocket man key ci = do
now <- getCurrentTime
join $ I.atomicModifyIORef (mConns man) (go now)
where
go _ ManagerClosed = (ManagerClosed , connectionClose ci)
go now mc@(ManagerOpen idleCount m)
| idleCount >= mIdleConnectionCount man = (mc, connectionClose ci)
| otherwise = case Map.lookup key m of
Nothing ->
let cnt' = idleCount + 1
m' = ManagerOpen cnt' (Map.insert key (One ci now) m)
in m' `seq` (m', return ())
Just l ->
let (l', mx) = addToList now (mMaxConns man) ci l
cnt' = idleCount + maybe 0 (const 1) mx
m' = ManagerOpen cnt' (Map.insert key l' m)
in m' `seq` (m', maybe (return ()) connectionClose mx)
-- | Add a new element to the list, up to the given maximum number. If we're
-- already at the maximum, return the new value as leftover.
addToList :: UTCTime -> Int -> a -> NonEmptyList a -> (NonEmptyList a, Maybe a)
addToList _ i x l | i <= 1 = (l, Just x)
addToList now _ x l@One{} = (Cons x 2 now l, Nothing)
addToList now maxCount x l@(Cons _ currCount _ _)
| maxCount > currCount = (Cons x (currCount + 1) now l, Nothing)
| otherwise = (l, Just x)
-- | Create a 'Manager'. You may manually call 'closeManager' to shut it down,
-- or allow the @Manager@ to be shut down automatically based on garbage
-- collection.
--
-- Creating a new 'Manager' is a relatively expensive operation, you are
-- advised to share a single 'Manager' between requests instead.
--
-- The first argument to this function is often 'defaultManagerSettings',
-- though add-on libraries may provide a recommended replacement.
--
-- Since 0.1.0
newManager :: ManagerSettings -> IO Manager
newManager ms = do
rawConnection <- managerRawConnection ms
tlsConnection <- managerTlsConnection ms
tlsProxyConnection <- managerTlsProxyConnection ms
mapRef <- I.newIORef $! ManagerOpen 0 Map.empty
wmapRef <- I.mkWeakIORef mapRef $ closeManager' mapRef
_ <- forkIO $ reap wmapRef
let manager = Manager
{ mConns = mapRef
, mMaxConns = managerConnCount ms
, mResponseTimeout = managerResponseTimeout ms
, mRawConnection = rawConnection
, mTlsConnection = tlsConnection
, mTlsProxyConnection = tlsProxyConnection
, mRetryableException = managerRetryableException ms
, mWrapIOException = managerWrapIOException ms
, mIdleConnectionCount = managerIdleConnectionCount ms
}
return manager
-- | Collect and destroy any stale connections.
reap :: Weak (I.IORef ConnsMap) -> IO ()
reap wmapRef =
mask_ loop
where
loop = do
threadDelay (5 * 1000 * 1000)
mmapRef <- deRefWeak wmapRef
case mmapRef of
Nothing -> return () -- manager is closed
Just mapRef -> goMapRef mapRef
goMapRef mapRef = do
now <- getCurrentTime
let isNotStale time = 30 `addUTCTime` time >= now
toDestroy <- I.atomicModifyIORef mapRef (findStaleWrap isNotStale)
mapM_ safeConnClose toDestroy
loop
findStaleWrap _ ManagerClosed = (ManagerClosed, [])
findStaleWrap isNotStale (ManagerOpen idleCount m) =
let (x, y) = findStale isNotStale m
in (ManagerOpen (idleCount - length y) x, y)
findStale isNotStale =
findStale' id id . Map.toList
where
findStale' destroy keep [] = (Map.fromList $ keep [], destroy [])
findStale' destroy keep ((connkey, nelist):rest) =
findStale' destroy' keep' rest
where
-- Note: By definition, the timestamps must be in descending order,
-- so we don't need to traverse the whole list.
(notStale, stale) = span (isNotStale . fst) $ neToList nelist
destroy' = destroy . (map snd stale++)
keep' =
case neFromList notStale of
Nothing -> keep
Just x -> keep . ((connkey, x):)
flushStaleCerts now =
Map.fromList . mapMaybe flushStaleCerts' . Map.toList
where
flushStaleCerts' (host', inner) =
case mapMaybe flushStaleCerts'' $ Map.toList inner of
[] -> Nothing
pairs ->
let x = take 10 pairs
in x `seqPairs` Just (host', Map.fromList x)
flushStaleCerts'' (certs, expires)
| expires > now = Just (certs, expires)
| otherwise = Nothing
seqPairs :: [(L.ByteString, UTCTime)] -> b -> b
seqPairs [] b = b
seqPairs (p:ps) b = p `seqPair` ps `seqPairs` b
seqPair :: (L.ByteString, UTCTime) -> b -> b
seqPair (lbs, utc) b = lbs `seqLBS` utc `seqUTC` b
seqLBS :: L.ByteString -> b -> b
seqLBS lbs b = L.length lbs `seq` b
seqUTC :: UTCTime -> b -> b
seqUTC (UTCTime day dt) b = day `seqDay` dt `seqDT` b
seqDay :: Day -> b -> b
seqDay (ModifiedJulianDay i) b = i `deepseq` b
seqDT :: DiffTime -> b -> b
seqDT = seq
neToList :: NonEmptyList a -> [(UTCTime, a)]
neToList (One a t) = [(t, a)]
neToList (Cons a _ t nelist) = (t, a) : neToList nelist
neFromList :: [(UTCTime, a)] -> Maybe (NonEmptyList a)
neFromList [] = Nothing
neFromList [(t, a)] = Just (One a t)
neFromList xs =
Just . snd . go $ xs
where
go [] = error "neFromList.go []"
go [(t, a)] = (2, One a t)
go ((t, a):rest) =
let (i, rest') = go rest
i' = i + 1
in i' `seq` (i', Cons a i t rest')
-- | Close all connections in a 'Manager'.
--
-- Note that this doesn't affect currently in-flight connections,
-- meaning you can safely use it without hurting any queries you may
-- have concurrently running.
--
-- Since 0.1.0
closeManager :: Manager -> IO ()
closeManager = closeManager' . mConns
closeManager' :: I.IORef ConnsMap
-> IO ()
closeManager' connsRef = mask_ $ do
!m <- I.atomicModifyIORef connsRef $ \x -> (ManagerClosed, x)
case m of
ManagerClosed -> return ()
ManagerOpen _ m -> mapM_ (nonEmptyMapM_ safeConnClose) $ Map.elems m
-- | Create, use and close a 'Manager'.
--
-- Since 0.2.1
withManager :: ManagerSettings -> (Manager -> IO a) -> IO a
withManager settings = bracket (newManager settings) closeManager
safeConnClose :: Connection -> IO ()
safeConnClose ci = connectionClose ci `catch` \(_ :: IOException) -> return ()
nonEmptyMapM_ :: Monad m => (a -> m ()) -> NonEmptyList a -> m ()
nonEmptyMapM_ f (One x _) = f x
nonEmptyMapM_ f (Cons x _ _ l) = f x >> nonEmptyMapM_ f l
-- | This function needs to acquire a @ConnInfo@- either from the @Manager@ or
-- via I\/O, and register it with the @ResourceT@ so it is guaranteed to be
-- either released or returned to the manager.
getManagedConn
:: Manager
-> ConnKey
-> IO Connection
-> IO (ConnRelease, Connection, ManagedConn)
-- We want to avoid any holes caused by async exceptions, so let's mask.
getManagedConn man key open = mask $ \restore -> do
-- Try to take the socket out of the manager.
mci <- takeSocket man key
(ci, isManaged) <-
case mci of
-- There wasn't a matching connection in the manager, so create a
-- new one.
Nothing -> do
ci <- restore open
return (ci, Fresh)
-- Return the existing one
Just ci -> return (ci, Reused)
-- When we release this connection, we can either reuse it (put it back in
-- the manager) or not reuse it (close the socket). We set up a mutable
-- reference to track what we want to do. By default, we say not to reuse
-- it, that way if an exception is thrown, the connection won't be reused.
toReuseRef <- I.newIORef DontReuse
wasReleasedRef <- I.newIORef False
-- When the connection is explicitly released, we update our toReuseRef to
-- indicate what action should be taken, and then call release.
let connRelease r = do
I.writeIORef toReuseRef r
releaseHelper
releaseHelper = mask $ \restore -> do
wasReleased <- I.atomicModifyIORef wasReleasedRef $ \x -> (True, x)
unless wasReleased $ do
toReuse <- I.readIORef toReuseRef
restore $ case toReuse of
Reuse -> putSocket man key ci
DontReuse -> connectionClose ci
return (connRelease, ci, isManaged)
-- | Create an exception to be thrown if the connection for the given request
-- fails.
failedConnectionException :: Request -> HttpException
failedConnectionException req =
FailedConnectionException host' port'
where
(_, host', port') = getConnDest req
getConnDest :: Request -> (Bool, String, Int)
getConnDest req =
case proxy req of
Just p -> (True, S8.unpack (proxyHost p), proxyPort p)
Nothing -> (False, S8.unpack $ host req, port req)
getConn :: Request
-> Manager
-> IO (ConnRelease, Connection, ManagedConn)
getConn req m
-- Stop Mac OS X from getting high:
-- https://github.com/snoyberg/http-client/issues/40#issuecomment-39117909
| S8.null h = throwIO $ InvalidDestinationHost h
| otherwise =
getManagedConn m (ConnKey connKeyHost connport (secure req)) $
wrapConnectExc $ go connaddr connhost connport
where
h = host req
(useProxy, connhost, connport) = getConnDest req
(connaddr, connKeyHost) =
case (hostAddress req, useProxy) of
(Just ha, False) -> (Just ha, HostAddress ha)
_ -> (Nothing, HostName $ T.pack connhost)
wrapConnectExc = handle $ \e ->
throwIO $ FailedConnectionException2 connhost connport (secure req)
(toException (e :: IOException))
go =
case (secure req, useProxy) of
(False, _) -> mRawConnection m
(True, False) -> mTlsConnection m
(True, True) ->
let ultHost = host req
ultPort = port req
connstr = S8.concat
[ "CONNECT "
, ultHost
, ":"
, S8.pack $ show ultPort
, " HTTP/1.1\r\n\r\n"
]
parse conn = do
sh@(StatusHeaders status _ _) <- parseStatusHeaders conn
unless (status == status200) $
throwIO $ ProxyConnectException ultHost ultPort $ Left $ S8.pack $ show sh
in mTlsProxyConnection m connstr parse (S8.unpack ultHost)