module Network.Wai.Handler.Warp.Header where
import Data.Array
import Data.Array.ST
import Network.HTTP.Types
import Network.Wai.Handler.Warp.Types
type IndexedHeader = Array Int (Maybe HeaderValue)
indexRequestHeader :: RequestHeaders -> IndexedHeader
indexRequestHeader hdr = traverseHeader hdr requestMaxIndex requestKeyIndex
data RequestHeaderIndex = ReqContentLength
| ReqTransferEncoding
| ReqExpect
| ReqConnection
| ReqRange
| ReqHost
| ReqIfModifiedSince
| ReqIfUnmodifiedSince
| ReqIfRange
| ReqReferer
| ReqUserAgent
deriving (Enum,Bounded)
requestMaxIndex :: Int
requestMaxIndex = fromEnum (maxBound :: RequestHeaderIndex)
requestKeyIndex :: HeaderName -> Int
requestKeyIndex "content-length" = fromEnum ReqContentLength
requestKeyIndex "transfer-encoding" = fromEnum ReqTransferEncoding
requestKeyIndex "expect" = fromEnum ReqExpect
requestKeyIndex "connection" = fromEnum ReqConnection
requestKeyIndex "range" = fromEnum ReqRange
requestKeyIndex "host" = fromEnum ReqHost
requestKeyIndex "if-modified-since" = fromEnum ReqIfModifiedSince
requestKeyIndex "if-unmodified-since" = fromEnum ReqIfUnmodifiedSince
requestKeyIndex "if-range" = fromEnum ReqIfRange
requestKeyIndex "referer" = fromEnum ReqReferer
requestKeyIndex "user-agent" = fromEnum ReqUserAgent
requestKeyIndex _ = 1
defaultIndexRequestHeader :: IndexedHeader
defaultIndexRequestHeader = array (0,requestMaxIndex) [(i,Nothing)|i<-[0..requestMaxIndex]]
indexResponseHeader :: ResponseHeaders -> IndexedHeader
indexResponseHeader hdr = traverseHeader hdr responseMaxIndex responseKeyIndex
data ResponseHeaderIndex = ResContentLength
| ResServer
| ResDate
deriving (Enum,Bounded)
responseMaxIndex :: Int
responseMaxIndex = fromEnum (maxBound :: ResponseHeaderIndex)
responseKeyIndex :: HeaderName -> Int
responseKeyIndex "content-length" = fromEnum ResContentLength
responseKeyIndex "server" = fromEnum ResServer
responseKeyIndex "date" = fromEnum ResDate
responseKeyIndex _ = 1
traverseHeader :: [Header] -> Int -> (HeaderName -> Int) -> IndexedHeader
traverseHeader hdr maxidx getIndex = runSTArray $ do
arr <- newArray (0,maxidx) Nothing
mapM_ (insert arr) hdr
return arr
where
insert arr (key,val)
| idx == 1 = return ()
| otherwise = writeArray arr idx (Just val)
where
idx = getIndex key