module Network.HPACK.Table.Header (
HeaderTable(..)
, newHeaderTable
, printHeaderTable
, insertEntry
, toIndexValue
) where
import Data.Array.IO (IOArray, newArray, readArray, writeArray)
import qualified Data.ByteString.Char8 as BS
import Network.HPACK.Table.Entry
data HeaderTable = HeaderTable {
maxNumOfEntries :: Int
, offset :: Index
, numOfEntries :: Int
, circularTable :: !(IOArray Index Entry)
, headerTableSize :: Size
, maxHeaderTableSize :: Size
}
printHeaderTable :: HeaderTable -> IO ()
printHeaderTable (HeaderTable maxN off n tbl tblsiz _) = do
es <- mapM (readArray tbl . adj maxN) [beg .. end]
let ts = zip [1..] es
mapM_ printEntry ts
putStrLn $ " Table size: " ++ show tblsiz
where
beg = off + 1
end = off + n
printEntry :: (Index,Entry) -> IO ()
printEntry (i,e) = do
putStr "[ "
putStr $ show i
putStr "] (s = "
putStr $ show $ entrySize e
putStr ") "
BS.putStr $ entryHeaderName e
putStr ": "
BS.putStrLn $ entryHeaderValue e
newHeaderTable :: Size -> IO HeaderTable
newHeaderTable maxsiz = do
tbl <- newArray (0,end) dummyEntry
return HeaderTable {
maxNumOfEntries = maxN
, offset = end
, numOfEntries = 0
, circularTable = tbl
, headerTableSize = 0
, maxHeaderTableSize = maxsiz
}
where
maxN = maxNumbers maxsiz
end = maxN 1
insertEntry :: Entry -> HeaderTable -> IO (HeaderTable,[Index])
insertEntry e hdrtbl = insertOne e hdrtbl >>= adjustTableSize
insertOne :: Entry -> HeaderTable -> IO HeaderTable
insertOne e hdrtbl@(HeaderTable maxN off n tbl tsize _) = do
writeArray tbl i e
return $ hdrtbl {
offset = off'
, numOfEntries = n + 1
, headerTableSize = tsize'
}
where
i = off
tsize' = tsize + entrySize e
off' = adj maxN (off 1)
adjustTableSize :: HeaderTable -> IO (HeaderTable, [Index])
adjustTableSize hdrtbl = adjust hdrtbl []
adjust :: HeaderTable -> [Index] -> IO (HeaderTable, [Index])
adjust hdrtbl is
| tsize <= maxtsize = return (hdrtbl, is)
| otherwise = do
(hdrtbl', i) <- removeOne hdrtbl
adjust hdrtbl' (i:is)
where
tsize = headerTableSize hdrtbl
maxtsize = maxHeaderTableSize hdrtbl
removeOne :: HeaderTable -> IO (HeaderTable,Index)
removeOne hdrtbl@(HeaderTable maxN off n tbl tsize _) = do
let i = adj maxN (off + n)
e <- readArray tbl i
writeArray tbl i dummyEntry
let tsize' = tsize entrySize e
let hdrtbl' = hdrtbl {
numOfEntries = n 1
, headerTableSize = tsize'
}
return (hdrtbl',n)
toIndexValue :: HeaderName -> HeaderTable -> IO (Maybe (Index, HeaderValue))
toIndexValue k (HeaderTable maxN off n tbl _ _) = go 1
where
go i
| i > n = return Nothing
| otherwise = do
let idx = adj maxN (off + i)
e <- readArray tbl idx
if entryHeaderName e == k then
return $ Just (i, entryHeaderValue e)
else
go (i+1)
adj :: Int -> Int -> Int
adj maxN x = (x + maxN) `mod` maxN