| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Network.Wait
Description
This module contains computations which wait for some networked service
to become available, subject to some retry policy from Control.Retry.
The waitSocketWith function is the most general function exported by
this module, but several variants exist for convenience. You may wish
to start out with e.g. waitTcp or waitSocket initially and move
on to the more feature-rich variants if you need their functionality.
Synopsis
- waitTcp :: (MonadIO m, MonadMask m) => RetryPolicyM m -> HostName -> ServiceName -> m Socket
- waitTcpVerbose :: (MonadIO m, MonadMask m) => (String -> m ()) -> RetryPolicyM m -> HostName -> ServiceName -> m Socket
- waitTcpVerboseFormat :: forall e m. (MonadIO m, MonadMask m, Exception e) => (Bool -> e -> RetryStatus -> m ()) -> RetryPolicyM m -> HostName -> ServiceName -> m Socket
- waitTcpWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> HostName -> ServiceName -> m Socket
- waitSocket :: (MonadIO m, MonadMask m) => RetryPolicyM m -> AddrInfo -> m Socket
- waitSocketVerbose :: (MonadIO m, MonadMask m) => (String -> m ()) -> RetryPolicyM m -> AddrInfo -> m Socket
- waitSocketVerboseFormat :: forall e m. (MonadIO m, MonadMask m, Exception e) => (Bool -> e -> RetryStatus -> m ()) -> RetryPolicyM m -> AddrInfo -> m Socket
- waitSocketWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> AddrInfo -> m Socket
- recoveringWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> m a -> m a
TCP
waitTcp :: (MonadIO m, MonadMask m) => RetryPolicyM m -> HostName -> ServiceName -> m Socket Source #
waitTcp retryPolicy hostName serviceName is a variant of waitTcpWith
which does not install any additional handlers.
waitTcp retryPolicyDefault "localhost" "80"
waitTcpVerbose :: (MonadIO m, MonadMask m) => (String -> m ()) -> RetryPolicyM m -> HostName -> ServiceName -> m Socket Source #
waitTcpVerbose outputHandler retryPolicy addrInfo is a variant
of waitTcpVerboseFormat which catches all exceptions derived from
SomeException and formats retry attempt information using defaultLogMsg
before passing the resulting String to out.
waitTcpVerbose putStrLn retryPolicyDefault "localhost" "80"
waitTcpVerboseFormat :: forall e m. (MonadIO m, MonadMask m, Exception e) => (Bool -> e -> RetryStatus -> m ()) -> RetryPolicyM m -> HostName -> ServiceName -> m Socket Source #
waitTcpVerboseFormat outputHandler retryPolicy addrInfo is a
variant of waitTcpWith which installs an extra handler based on
logRetries which passes status information for each retry attempt
to outputHandler.
waitTcpVerboseFormat @SomeException
(\b ex st -> putStrLn $ defaultLogMsg b ex st)
retryPolicyDefault "localhost" "80"waitTcpWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> HostName -> ServiceName -> m Socket Source #
waitTcpWith extraHandlers retryPolicy hostName serviceName is a
variant of waitSocketWith which constructs a suitable AddrInfo value
for a TCP socket from hostName and serviceName.
Sockets
waitSocket :: (MonadIO m, MonadMask m) => RetryPolicyM m -> AddrInfo -> m Socket Source #
waitSocket retryPolicy addrInfo is a variant of waitSocketWith which
does not install any additional exception handlers.
waitSocketVerbose :: (MonadIO m, MonadMask m) => (String -> m ()) -> RetryPolicyM m -> AddrInfo -> m Socket Source #
waitSocketVerbose outputHandler retryPolicy addrInfo is a variant
of waitSocketVerboseFormat which catches all exceptions derived from
SomeException and formats retry attempt information using defaultLogMsg
before passing the resulting String to out.
waitSocketVerboseFormat :: forall e m. (MonadIO m, MonadMask m, Exception e) => (Bool -> e -> RetryStatus -> m ()) -> RetryPolicyM m -> AddrInfo -> m Socket Source #
waitSocketVerboseFormat outputHandler retryPolicy addrInfo is a
variant of waitSocketWith which installs an extra handler based on
logRetries which passes status information for each retry attempt
to outputHandler.
waitSocketWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> AddrInfo -> m Socket Source #
waitSocketWith extraHandlers retryPolicy addrInfo will attempt to
connect to addrInfo. If the connection fails, retryPolicy is used
to determine whether (and how often) this function should attempt to
retry establishing the connection. By default, this function will
retry after all exceptions (except for those given by
skipAsyncExceptions). This behaviour may be customised with
extraHandlers which are installed after skipAsyncExceptions, but
before the default exception handler. The extraHandlers may also
be used to report retry attempts to e.g. the standard output or a
logger.
Utility
recoveringWith :: (MonadIO m, MonadMask m) => [RetryStatus -> Handler m Bool] -> RetryPolicyM m -> m a -> m a Source #
recoveringWith extraHandlers retryPolicy action will attempt to
run action. If the action fails, retryPolicy is used
to determine whether (and how often) this function should attempt to
retry action. By default, this function will retry after all
exceptions (except for those given by skipAsyncExceptions). This
behaviour may be customised with extraHandlers which are installed
after skipAsyncExceptions, but before the default exception handler.
The extraHandlers may also be used to report retry attempts to e.g.
the standard output or a logger.