Fix for insane memory usage

[Lucu.git] / Network / HTTP / Lucu / Parser.hs

diff --git a/Network/HTTP/Lucu/Parser.hs b/Network/HTTP/Lucu/Parser.hs
index 6c66e7f42e3c02c7fc12b63ceab537dfda0774d1..9a36ad5d83978048d3414b26090146db576a9562 100644 (file)
--- a/Network/HTTP/Lucu/Parser.hs
+++ b/Network/HTTP/Lucu/Parser.hs
@@ -39,6 +39,7 @@ module Network.HTTP.Lucu.Parser
     , hexDigit
     , notFollowedBy
     , many
+    , manyChar
     , many1
     , count
     , option
@@ -55,6 +56,7 @@ import           Control.Monad.State.Strict
 import qualified Data.ByteString.Lazy as Lazy (ByteString)
 import qualified Data.ByteString.Lazy.Char8 as B hiding (ByteString)
 import qualified Data.Foldable as Fold
+import           Data.Int
 import qualified Data.Sequence as Seq
 import           Data.Sequence (Seq, (|>))
 
@@ -88,8 +90,8 @@ instance Monad Parser where
                                                 return IllegalInput
                              ReachedEOF   -> do put saved -- 状態を復歸
                                                 return ReachedEOF
-    return x = x `seq` Parser $! return $! Success x
-    fail _   = Parser $! return $! IllegalInput
+    return !x = Parser $! return $! Success x
+    fail _    = Parser $! return $! IllegalInput
 
 -- |@'failP'@ is just a synonym for @'Prelude.fail'
 -- 'Prelude.undefined'@.
@@ -99,17 +101,15 @@ failP = fail undefined
 -- |@'parse' p bstr@ parses @bstr@ with @p@ and returns @(# result,
 -- remaining #)@.
 parse :: Parser a -> Lazy.ByteString -> (# ParserResult a, Lazy.ByteString #)
-parse p input -- input は lazy である必要有り。
-    = p `seq`
-      let (result, state') = runState (runParser p) (PST input True)
+parse !p input -- input は lazy である必要有り。
+    = let (!result, state') = runState (runParser p) (PST input True)
       in
-        result `seq` (# result, pstInput state' #) -- pstInput state' も lazy である必要有り。
+        (# result, pstInput state' #) -- pstInput state' も lazy である必要有り。
 
 -- |@'parseStr' p str@ packs @str@ and parses it.
 parseStr :: Parser a -> String -> (# ParserResult a, Lazy.ByteString #)
-parseStr p input
-    = p `seq` -- input は lazy である必要有り。
-      parse p (B.pack input)
+parseStr !p input -- input は lazy である必要有り。
+    = parse p (B.pack input)
 
 
 anyChar :: Parser Char
@@ -132,16 +132,16 @@ eof = Parser $!
 
 -- |@'allowEOF' p@ makes @p@ treat reaching EOF a normal failure.
 allowEOF :: Parser a -> Parser a
-allowEOF f = f `seq`
-             Parser $! do saved@(PST _ isEOFFatal) <- get
-                          put $! saved { pstIsEOFFatal = False }
+allowEOF !f
+    = Parser $! do saved@(PST _ isEOFFatal) <- get
+                   put $! saved { pstIsEOFFatal = False }
 
-                          result <- runParser f
+                   result <- runParser f
                          
-                          state <- get
-                          put $! state { pstIsEOFFatal = isEOFFatal }
+                   state <- get
+                   put $! state { pstIsEOFFatal = isEOFFatal }
 
-                          return result
+                   return result
 
 
 satisfy :: (Char -> Bool) -> Parser Char
@@ -158,9 +158,22 @@ char !c = satisfy (== c)
 
 
 string :: String -> Parser String
-string !str = str `seq`
-              do mapM_ char str
-                 return str
+string !str
+    = let bs  = B.pack str
+          len = B.length bs
+      in
+        Parser $!
+        do st <- get
+           let (bs', rest) = B.splitAt len $ pstInput st
+               st'         = st { pstInput = rest }
+           if B.length bs' < len then
+               return ReachedEOF
+             else
+               if bs == bs' then
+                   do put st'
+                      return $ Success str
+               else
+                   return IllegalInput
 
 
 infixr 0 <|>
@@ -168,9 +181,8 @@ infixr 0 <|>
 -- |This is the backtracking alternation. There is no non-backtracking
 -- equivalent.
 (<|>) :: Parser a -> Parser a -> Parser a
-f <|> g
-    = f `seq` g `seq`
-      Parser $! do saved  <- get -- 状態を保存
+(!f) <|> (!g)
+    = Parser $! do saved  <- get -- 状態を保存
                    result <- runParser f
                    case result of
                      Success a    -> return $! Success a
@@ -240,6 +252,32 @@ many !p = Parser $!
                                    else
                                        (# Success (Fold.toList soFar), st #)
 
+manyChar :: Parser Char -> Parser Lazy.ByteString
+manyChar !p = Parser $!
+              do state <- get
+                 case scan' state 0 of
+                   Success len
+                       -> do let (bs, rest) = B.splitAt len (pstInput state)
+                                 state'     = state { pstInput = rest }
+                             put state'
+                             return $ Success bs
+                   ReachedEOF
+                       -> if pstIsEOFFatal state then
+                              return ReachedEOF
+                          else
+                              error "internal error"
+                   _   -> error "internal error"
+    where
+      scan' :: ParserState -> Int64 -> ParserResult Int64
+      scan' !st !soFar
+          = case runState (runParser p) st of
+              (Success _   , st') -> scan' st' (soFar + 1)
+              (IllegalInput, _  ) -> Success soFar
+              (ReachedEOF  , _  ) -> if pstIsEOFFatal st then
+                                         ReachedEOF
+                                     else
+                                         Success soFar
+
 
 many1 :: Parser a -> Parser [a]
 many1 !p = do x  <- p
@@ -266,20 +304,18 @@ count' !n !p !soFar = do saved  <- get
 
 -- def may be a _|_
 option :: a -> Parser a -> Parser a
-option def p = p `seq`
-               p <|> return def
+option def !p = p <|> return def
 
 
 sepBy :: Parser a -> Parser sep -> Parser [a]
-sepBy p sep = p `seq` sep `seq`
-              sepBy1 p sep <|> return []
+sepBy !p !sep = sepBy1 p sep <|> return []
 
 
 sepBy1 :: Parser a -> Parser sep -> Parser [a]
-sepBy1 p sep = p `seq` sep `seq`
-               do x  <- p
-                  xs <- many $! sep >> p
-                  return (x:xs)
+sepBy1 !p !sep
+    = do x  <- p
+         xs <- many $! sep >> p
+         return (x:xs)
 
 
 sp :: Parser Char