, UnicodeSyntax
#-}
module Network.HTTP.Lucu.Dispatcher.Internal
- ( SchemeMapper(..)
- , SchemeMap
- , HostMapper(..)
+ ( HostMapper(..)
, HostMap
, ResourceMapper(..)
, ResourceMap
import Control.Monad.Trans.Maybe
import Control.Monad.Unicode
import Data.Collections
+import qualified Data.Collections.Newtype.TH as C
import qualified Data.Map as M
import Data.Monoid
import Data.Monoid.Unicode
import Network.HTTP.Lucu.Resource.Internal
import Network.HTTP.Lucu.Utils
import Network.URI hiding (path)
-import Prelude hiding (filter, lookup, null)
+import Prelude hiding (filter, foldr, lookup, null)
import Prelude.Unicode
--- |FIXME: docs
+-- |Class of maps from 'Host' to 'ResourceMap' to provide name-based
+-- virtual hosts.
--
--- Minimal complete definition: 'findHostMap'
-class SchemeMapper α where
- findHostMap ∷ Scheme → α → MaybeT IO HostMap
- schemeMap ∷ α → SchemeMap
- {-# INLINE schemeMap #-}
- schemeMap = SMap
-
--- |Container type for the 'SchemeMapper' type class.
-data SchemeMap = ∀α. SchemeMapper α ⇒ SMap α
-
--- |FIXME: docs
+-- Note that Lucu currently does not implement neither RFC 2817
+-- connection upgrading (<http://tools.ietf.org/html/rfc2817>) nor RFC
+-- 3546 server name indication
+-- (<http://tools.ietf.org/html/rfc3546#section-3.1>) so you won't be
+-- able to host more than one SSL virtual host on the same port
+-- without using wildcard certificates
+-- (<http://tools.ietf.org/html/rfc2818#section-3.1>).
--
-- Minimal complete definition: 'findResourceMap'
class HostMapper α where
+ -- |Find a repository of resources for the given host name if any.
findResourceMap ∷ Host → α → MaybeT IO ResourceMap
+ -- |Wrap an instance of 'HostMapper' in a monoidal, homogeneous
+ -- container.
hostMap ∷ α → HostMap
{-# INLINE hostMap #-}
hostMap = HMap
-- |Container type for the 'HostMapper' type class.
-data HostMap = ∀α. HostMapper α ⇒ HMap α
+data HostMap = ∀α. HostMapper α ⇒ HMap !α
--- |FIXME: docs
+-- |Class of maps from resource 'Path' to 'Resource'.
--
-- Minimal complete definition: 'findResource'
class ResourceMapper α where
- findResource ∷ PathSegments → α → MaybeT IO (PathSegments, Resource)
+ -- |Find a resource handler for the given resource path, along
+ -- with the path where the said handler was found. The found path
+ -- is usually the same as the queried path, but there are
+ -- situations where the found path is just a prefix of the queried
+ -- path. See 'greedy'.
+ findResource ∷ Path → α → MaybeT IO (Path, Resource)
+ -- |Wrap an instance of 'ResourceMapper' in a monoidal,
+ -- homogeneous container.
resourceMap ∷ α → ResourceMap
{-# INLINE resourceMap #-}
resourceMap = RMap
-- |Container type for the 'ResourceMapper' type class.
-data ResourceMap = ∀α. ResourceMapper α ⇒ RMap α
+data ResourceMap = ∀α. ResourceMapper α ⇒ RMap !α
--- |'ResourceTree' is an opaque structure which is a map from resource
--- path to 'Resource'.
+-- |'ResourceTree' is an opaque structure which a map from resource
+-- 'Path' to 'ResourceNode'.
--
-- @
-- 'fromList' [ ([] , 'nonGreedy' '$' 'Network.HTTP.Lucu.StaticFile.staticFile' \"\/usr\/include\/stdio.h\" ) -- \/
-- has no involvement in character encodings such as UTF-8, since RFC
-- 2616 (HTTP/1.1) says nothing about character encodings to be used
-- in \"http\" and \"https\" URI schemas.
-newtype ResourceTree = Tree (M.Map PathSegments ResourceNode)
+newtype ResourceTree = Tree (M.Map Path ResourceNode)
deriving Monoid
--- |FIXME: doc
+-- |A node of 'Resource' located somewhere in a 'ResourceTree'. Such
+-- nodes are either 'greedy' or 'nonGreedy'.
data ResourceNode
= Greedy { nResource ∷ !Resource }
| NonGreedy { nResource ∷ !Resource }
--- |FIXME: doc
+-- |Make a greedy resource node.
+--
+-- Say a client is trying to access \"\/aaa\/bbb\/ccc\' while there is
+-- no resource node at the path. If there are greedy resource nodes at
+-- \"\/aaa\/bbb\", \"\/aaa\" or \"/\" they will be chosen instead as a
+-- fallback. Greedy resource nodes are searched in depth-first
+-- order, just like CGI scripts.
greedy ∷ Resource → ResourceNode
{-# INLINE CONLIKE greedy #-}
greedy = Greedy
--- |FIXME: doc
+-- |Make a normal, non-greedy resource node.
nonGreedy ∷ Resource → ResourceNode
{-# INLINE CONLIKE nonGreedy #-}
nonGreedy = NonGreedy
--- Instances of SchemeMapper --------------------------------------------------
-instance SchemeMapper SchemeMap where
- {-# INLINE findHostMap #-}
- findHostMap s (SMap α) = findHostMap s α
- {-# INLINE schemeMap #-}
- schemeMap = id
-
--- |'HostMap's are also 'SchemeMapper's too, which matches to any
--- schemes.
-instance SchemeMapper HostMap where
- {-# INLINE findHostMap #-}
- findHostMap = const return
-
--- |'ResourceMap's are also 'SchemeMapper's too, which matches to any
--- schemes and hosts.
-instance SchemeMapper ResourceMap where
- {-# INLINE findHostMap #-}
- findHostMap _ r = return $ hostMap f
- where
- f ∷ Host → Maybe ResourceMap
- {-# INLINE f #-}
- f = const $ Just r
-
--- |@'insert' a b@ first tries @a@, and if it fails, tries @b@ next.
-instance SchemeMapper α ⇒ Unfoldable SchemeMap α where
- {-# INLINE insert #-}
- insert a (SMap b) = schemeMap c
- where
- c ∷ Scheme → MaybeT IO HostMap
- {-# INLINEABLE c #-}
- c s = findHostMap s a <|> findHostMap s b
- {-# INLINE empty #-}
- empty = (∅)
- {-# INLINE singleton #-}
- singleton = schemeMap
-
--- |@'mappend' a b@ first tries @a@, and if it fails, tries @b@ next.
-instance Monoid SchemeMap where
- {-# INLINE mempty #-}
- mempty = schemeMap e
- where
- e ∷ Scheme → MaybeT IO HostMap
- {-# INLINE e #-}
- e = const (fail (⊥))
- {-# INLINE mappend #-}
- mappend = insert
-
--- |Any 'Map's from 'Scheme' to 'HostMap' are also 'SchemeMapper's.
-instance Map α Scheme HostMap ⇒ SchemeMapper α where
- {-# INLINE findHostMap #-}
- findHostMap = (maybe (fail (⊥)) return ∘) ∘ lookup
-
--- |An IO-based scheme mapper.
-instance SchemeMapper (Scheme → MaybeT IO HostMap) where
- {-# INLINE findHostMap #-}
- findHostMap = flip id
-
--- |A pure scheme mapper.
-instance SchemeMapper (Scheme → Maybe HostMap) where
- {-# INLINE findHostMap #-}
- findHostMap = (maybe (fail (⊥)) return ∘) ∘ flip id
-
-- Instances of HostMapper ----------------------------------------------------
instance HostMapper HostMap where
{-# INLINE insert #-}
insert a (RMap b) = resourceMap c
where
- c ∷ PathSegments → MaybeT IO (PathSegments, Resource)
+ c ∷ Path → MaybeT IO (Path, Resource)
{-# INLINEABLE c #-}
c s = findResource s a <|> findResource s b
{-# INLINE empty #-}
{-# INLINE mempty #-}
mempty = resourceMap e
where
- e ∷ PathSegments → MaybeT IO (PathSegments, Resource)
+ e ∷ Path → MaybeT IO (Path, Resource)
{-# INLINE e #-}
e = const (fail (⊥))
{-# INLINE mappend #-}
mappend = insert
--- |Any 'Map's from 'PathSegments' to @('PathSegments', 'Resource')@
--- are also 'ResourceMapper's.
-instance Map α PathSegments (PathSegments, Resource) ⇒ ResourceMapper α where
+-- |Any 'Map's from 'Path' to @('Path', 'Resource')@ are also
+-- 'ResourceMapper's.
+instance Map α Path (Path, Resource) ⇒ ResourceMapper α where
{-# INLINE findResource #-}
findResource = (maybe (fail (⊥)) return ∘) ∘ lookup
-- |An IO-based resource mapper.
-instance ResourceMapper (PathSegments → MaybeT IO (PathSegments, Resource)) where
+instance ResourceMapper (Path → MaybeT IO (Path, Resource)) where
{-# INLINE findResource #-}
findResource = flip id
-- |A pure resource mapper.
-instance ResourceMapper (PathSegments → Maybe (PathSegments, Resource)) where
+instance ResourceMapper (Path → Maybe (Path, Resource)) where
{-# INLINE findResource #-}
findResource = (maybe (fail (⊥)) return ∘) ∘ flip id
-- Instances of ResourceTree --------------------------------------------------
-instance Unfoldable ResourceTree (PathSegments, ResourceNode) where
+instance Unfoldable ResourceTree (Path, ResourceNode) where
{-# INLINEABLE insert #-}
insert (p, n) (Tree m) = Tree $ insert (canonPath p, n) m
{-# INLINE empty #-}
{-# INLINEABLE canonPath #-}
canonPath = filter ((¬) ∘ null)
+C.derive [d| instance Foldable ResourceTree (Path, ResourceNode)
+ |]
+
+instance Collection ResourceTree (Path, ResourceNode) where
+ {-# INLINE filter #-}
+ filter f (Tree m) = Tree $ filter f m
+
-- |'findResource' performs the longest prefix match on the tree,
-- finding the most specific one.
instance ResourceMapper ResourceTree where
Just n → return (p, nResource n)
Nothing → findGreedyResource p m
-findGreedyResource ∷ (Monad m, Map α PathSegments ResourceNode)
- ⇒ PathSegments
+findGreedyResource ∷ (Monad m, Map α Path ResourceNode)
+ ⇒ Path
→ α
- → MaybeT m (PathSegments, Resource)
+ → MaybeT m (Path, Resource)
findGreedyResource p m
= case back p of
Nothing → fail (⊥)
_ → findGreedyResource p' m
-- dispatch -------------------------------------------------------------------
-dispatch ∷ SchemeMapper α ⇒ URI → α → MaybeT IO (PathSegments, Resource)
+dispatch ∷ HostMapper α ⇒ URI → α → MaybeT IO (Path, Resource)
dispatch uri
= (findResource (uriPathSegments uri) =≪)
- ∘ (findResourceMap (uriHost uri) =≪)
- ∘ findHostMap (uriCIScheme uri)
+ ∘ findResourceMap (uriHost uri)