Safe Haskell	None
Language	Haskell2010

Ouroboros.Network.PeerSelection.RootPeersDNS.DNSActions

Contents

DNS based actions for local and public root providers
DNSActions IO
Utils
- Resource
- Error type

Synopsis

data DNSActions resolver exception m = DNSActions {
- dnsResolverResource :: ResolvConf -> m ( Resource m ( DNSorIOError exception) resolver)
- dnsAsyncResolverResource :: ResolvConf -> m ( Resource m ( DNSorIOError exception) resolver)
- dnsLookupWithTTL :: ResolvConf -> resolver -> Domain -> m ([ DNSError ], [( IP , TTL )])
}
ioDNSActions :: LookupReqs -> DNSActions Resolver IOException IO
data LookupReqs
- = LookupReqAOnly
- | LookupReqAAAAOnly
- | LookupReqAAndAAAA
newtype Resource m err a = Resource {
- withResource :: m ( Either err a, Resource m err a)
}
withResource' :: MonadDelay m => Tracer m err -> NonEmpty DiffTime -> Resource m err a -> m (a, Resource m err a)
constantResource :: Applicative m => a -> Resource m err a
data DNSorIOError exception
- = DNSError ! DNSError
- | IOError !exception

DNS based actions for local and public root providers

data DNSActions resolver exception m Source #

Dictionary of DNS actions vocabulary

Constructors

DNSActions

Fields

dnsResolverResource :: ResolvConf -> m ( Resource m ( DNSorIOError exception) resolver)

TODO: it could be useful for publicRootPeersProvider .
dnsAsyncResolverResource :: ResolvConf -> m ( Resource m ( DNSorIOError exception) resolver)

Resource which passes the Resolver (or abstract resolver type) through a StrictTVar . Better than resolverResource when using in multiple threads.

On Windows we use a different implementation which always returns a newly initialised Resolver at each step. This is because on Windows we don't have a way to check that the network configuration has changed. The dns library is using 'GetNetworkParams@ win32 api call to get the list of default dns servers.
dnsLookupWithTTL :: ResolvConf -> resolver -> Domain -> m ([ DNSError ], [( IP , TTL )])

Like lookupA but also return the TTL for the results.

DNS library timeouts do not work reliably on Windows (#1873), hence the additional timeout.

DNSActions IO

ioDNSActions :: LookupReqs -> DNSActions Resolver IOException IO Source #

Bundle of DNS Actions that runs in IO The IPv4 and IPv6 addresses the node will be using should determine the LookupReqs so that we can avoid lookups for address types that wont be used.

data LookupReqs Source #

Constructors

LookupReqAOnly
LookupReqAAAAOnly
LookupReqAAndAAAA

Instances

Instances details

Show LookupReqs Source #
Instance details Defined in Ouroboros.Network.PeerSelection.RootPeersDNS.DNSActions Methods showsPrec :: Int -> LookupReqs -> ShowS Source # show :: LookupReqs -> String Source # showList :: [ LookupReqs ] -> ShowS Source #

Utils

Resource

newtype Resource m err a Source #

Evolving resource; We use it to reinitialise the dns library if the ` etc resolv.conf` file was modified.

Constructors

Resource
Fields withResource :: m ( Either err a, Resource m err a)

withResource' Source #

Arguments

:: MonadDelay m
=> Tracer m err
-> NonEmpty DiffTime	delays between each re-try
-> Resource m err a
-> m (a, Resource m err a)

Like withResource but retries untill success.

constantResource :: Applicative m => a -> Resource m err a Source #

Error type

data DNSorIOError exception Source #

Constructors

DNSError ! DNSError
IOError !exception

Instances

Instances details

Show exception => Show ( DNSorIOError exception) Source #
Instance details Defined in Ouroboros.Network.PeerSelection.RootPeersDNS.DNSActions Methods showsPrec :: Int -> DNSorIOError exception -> ShowS Source # show :: DNSorIOError exception -> String Source # showList :: [ DNSorIOError exception] -> ShowS Source #
Exception exception => Exception ( DNSorIOError exception) Source #
Instance details Defined in Ouroboros.Network.PeerSelection.RootPeersDNS.DNSActions Methods toException :: DNSorIOError exception -> SomeException Source # fromException :: SomeException -> Maybe ( DNSorIOError exception) Source # displayException :: DNSorIOError exception -> String Source #