module Text.HTML.TagSoup.Fast
( parseTags, renderTags, parseTagsT, renderTagsT, ensureUtf8Xml )
where
import Text.HTML.TagSoup (Tag(..))
import Text.HTML.TagSoup.Entity
import Text.StringLike (StringLike(..))
import qualified Data.ByteString.Char8 as B
import qualified Data.ByteString.Internal as B
import qualified Data.ByteString as B8
import Data.Bits
import Data.Word
import Foreign.Ptr
import Foreign.ForeignPtr
import Foreign.Storable
import System.IO.Unsafe
import Data.String
import Data.Char
import Data.Text (Text)
import qualified Data.Text as T
import qualified Data.Text.Encoding as T
import qualified Data.Text.ICU.Convert as ICU
import qualified Control.Exception as E
instance IsString Word8 where
fromString [c] = B.c2w c
type P = Ptr Word8
r :: P -> Word8
r ptr = B.inlinePerformIO (peek ptr)
instance Enum (Ptr Word8) where
succ p = p `plusPtr` 1
toEnum = error "toEnum: Ptr Word8"
fromEnum = error "toEnum: Ptr Word8"
pp :: Enum a => a -> a
pp !x = succ x
mm !y = pred y
toLowerBS bs@(B.PS fp o l) = B.inlinePerformIO $ withForeignPtr fp $ \ p -> do
let go !o 0 = return bs
go !o l = do
w <- peekByteOff p o
pokeByteOff p o (B.c2w $ toLower $ B.w2c w)
go (o+1) (l1)
go o l
parseTags :: B.ByteString -> [Tag B.ByteString]
parseTags s = B.inlinePerformIO $ withForeignPtr fp $ \ p ->
return $
map fixTag $ filter (/= TagText "") $
dat (p `plusPtr` offset) len 0
where (fp, offset, len) =
B.toForeignPtr $ B.copy s
fixTag (TagOpen t a) =
TagOpen t (map (\(a,v) -> (toLowerBS a, unescapeHtml v)) $
reverse a)
fixTag t = t
mkS !left !n = B.fromForeignPtr fp (offset + len left n) n
mkText unescape !left !n
| unescape = TagText $ unescapeHtml $ mkS left n
| otherwise = TagText $ mkS left n
script :: P -> Int -> Int -> [Tag B.ByteString]
script p 0 0 = []
script p 0 n = [mkText False 0 n]
script !p !l !n
| nextIC p l (toLowerUpperPairs "</script>") =
mkText False l n : TagClose "script"
: dat (p `plusPtr` 9) (l 9) 0
| otherwise = script (pp p) (mm l) (pp n)
style :: P -> Int -> Int -> [Tag B.ByteString]
style p 0 0 = []
style p 0 n = [mkText False 0 n]
style !p !l !n
| nextIC p l (toLowerUpperPairs "</style>") =
mkText False l n : TagClose "style"
: dat (p `plusPtr` 8) (l 8) 0
| otherwise = style (pp p) (mm l) (pp n)
dat :: P -> Int -> Int -> [Tag B.ByteString]
dat p 0 0 = []
dat p 0 n = [mkText True 0 n]
dat !p !left !n
| r p == "<" = mkText True left n : tagOpen (pp p) (mm left)
| otherwise = dat (pp p) (mm left) (pp n)
tdat !t !p !l = t : case t of
TagOpen "script" _ -> script p l 0
TagOpen "style" _ -> style p l 0
_ -> dat p l 0
tagOpen p 0 = dat p 0 1
tagOpen !p !left
| r p == "!" = markupDeclOpen (pp p) (mm left)
| alpha (r p) || r p == "?" = tagName True (pp p) (mm left) 1
| r p == "/" = closeTagOpen (pp p) (mm left)
| otherwise = dat p left 1
closeTagOpen p 0 = dat p 0 2
closeTagOpen !p !left
| alphaBQ (r p) = tagName False (pp p) (mm left) 1
| otherwise = dat p 0 2
tagName o p 0 n = []
tagName !o !p !left !n
| space (r p) = beforeAttName tag (pp p) (mm left)
| r p == ">" = tdat tag (pp p) (mm left)
| r p == "?" || r p == "/" =
selfClosingStartTag tag (pp p) (mm left)
| otherwise = tagName o (pp p) (mm left) (pp n)
where tag | o = TagOpen (toLowerBS $ mkS left n) []
| otherwise = TagClose (toLowerBS $ mkS left n)
markupDeclOpen p 0 = dat p 0 2
markupDeclOpen !p !l
| alpha (r p) = tagName True (pp p) (mm l) 1
| next p l "--" = commentStart (p `plusPtr` 2) (l 2) 0
| next p l "[CDATA[" = cdataSection (p `plusPtr` 7) (l 7) 0
| otherwise = dat p l 2
beforeAttName t p 0 = [t]
beforeAttName !t !p !l
| space (r p) = beforeAttName t (pp p) (mm l)
| r p == ">" = tdat t (pp p) (mm l)
| r p == "?" || r p == "/" = selfClosingStartTag t (pp p) (mm l)
| otherwise = attName t (pp p) (mm l) 1
attName t p 0 n = [t]
attName !t !p !l !n
| space (r p) = afterAttName t (mkS l n) (pp p) (mm l)
| r p == ">" = tdat (addAttr t (mkS l n) "") (pp p) (mm l)
| r p == "?" || r p == "/" =
selfClosingStartTag (addAttr t (mkS l n) "") (pp p) (mm l)
| r p == "=" = beforeAttValue t (mkS l n) (pp p) (mm l)
| otherwise = attName t (pp p) (mm l) (pp n)
afterAttName t a p 0 = [t]
afterAttName !t !a !p !l
| space (r p) = afterAttName t a (pp p) (mm l)
| r p == "=" = beforeAttValue t a (pp p) (mm l)
| r p == ">" = tdat (addAttr t a "") (pp p) (mm l)
| r p == "?" || r p == "/" =
selfClosingStartTag (addAttr t a "") (pp p) (mm l)
| r p == "'" || r p == "\"" = attValue (r p) t a (pp p) (mm l) 0
| otherwise = attName (addAttr t a "") (pp p) (mm l) 1
beforeAttValue t a p 0 = [t]
beforeAttValue !t !a !p !l
| space (r p) = beforeAttValue t a (pp p) (mm l)
| r p == ">" = tdat (addAttr t a "") (pp p) (mm l)
| r p == "'" || r p == "\"" = attValue (r p) t a (pp p) (mm l) 0
| otherwise = attValueUnquoted t a (pp p) (mm l) 1
attValue end t a p 0 n = [t]
attValue !end !t !a !p !l !n
| r p == end = beforeAttName (addAttr t a (mkS l n)) (pp p) (mm l)
| otherwise = attValue end t a (pp p) (mm l) (pp n)
attValueUnquoted t a p 0 n = [t]
attValueUnquoted !t !a !p !l !n
| space (r p) = beforeAttName (addAttr t a (mkS l n)) (pp p) (mm l)
| r p == ">"
= beforeAttName (addAttr t a (mkS l n)) p l
| otherwise = attValueUnquoted t a (pp p) (mm l) (pp n)
commentStart p 0 n = []
commentStart !p !l !n
| next p l "-->" = dat (p `plusPtr` 3) (l 3) 0
| otherwise = commentStart (pp p) (mm l) (pp n)
cdataSection p 0 n = dat p 0 n
cdataSection !p !l !n
| next p l "]]>" = mkText False l n : dat (p `plusPtr` 3) (l3) 0
| otherwise = cdataSection (pp p) (mm l) (pp n)
selfClosingStartTag t p 0 = closeTag t []
selfClosingStartTag !t !p !l
| r p == ">" = closeTag t $ dat (pp p) (mm l) 0
| otherwise = beforeAttName t p l
addAttr (TagOpen !tn !ta) !a !v = TagOpen tn ((a, v):ta)
addAttr t _ _ = t
closeTag !t@(TagOpen !tn _) !r = t : TagClose tn : r
closeTag !t !r = t : r
space 0x20 = True
space !n = n >= 9 && n <= 13
alpha !c = (c >= "a" && c <= "z") || (c >= "A" && c <= "Z")
alphaBQ !c = alpha c || c == "?" || c == "!"
next p l [] = True
next p 0 _ = False
next !p !l (x:xs) = (r p == B.c2w x) && next (pp p) (mm l) xs
toLowerUpperPairs s = [(B.c2w $ toLower x, B.c2w $ toUpper x) | x <- s]
nextIC p l [] = True
nextIC p 0 _ = False
nextIC !p !l ((a,b):xs) = (r p == a || r p == b) && nextIC (pp p) (mm l) xs
unescapeHtml :: B.ByteString -> B.ByteString
unescapeHtml s
| not (B8.elem "&" s) = s
| B.length s' == 0 = s
| otherwise = s'
where s' = B.inlinePerformIO $ withForeignPtr fp $ \ src ->
B.createAndTrim (len*2) $ \ dst -> do
(ch, dst') <- go (src `plusPtr` offset) dst len False
return $ if ch then dst' `minusPtr` dst else 0
(fp, offset, len) = B.toForeignPtr s
go :: P -> P -> Int -> Bool -> IO (Bool, P)
go !s !d !0 !c = return (c, d)
go !s !d !l !c
| r s /= "&" =
poke d (r s) >> go (pp s) (pp d) (mm l) c
| otherwise = entity (pp s) d (mm l) 9 [] c
entity !s !d !l !n !acc !c
| n == 0 || l == 0 =
poke d "&" >> go (s `plusPtr` (n9)) (pp d) (l+9n) c
| r s /= ";" =
entity (pp s) d (mm l) (mm n) (B.w2c (r s) : acc) c
| otherwise = case lookupEntity $ reverse acc of
Nothing ->
poke d "&" >> go (s `plusPtr` (n9)) (pp d) (l+9n) c
Just i -> do
let put !d [] = go (pp s) d (mm l) True
put !d (x:xs) =
poke d x >> put (pp d) xs
put d $ encodeChar i
encodeChar :: Char -> [Word8]
encodeChar = map fromIntegral . go . ord
where
go oc
| oc <= 0x7f = [oc]
| oc <= 0x7ff = [ 0xc0 + (oc `shiftR` 6)
, 0x80 + oc .&. 0x3f
]
| oc <= 0xffff = [ 0xe0 + (oc `shiftR` 12)
, 0x80 + ((oc `shiftR` 6) .&. 0x3f)
, 0x80 + oc .&. 0x3f
]
| otherwise = [ 0xf0 + (oc `shiftR` 18)
, 0x80 + ((oc `shiftR` 12) .&. 0x3f)
, 0x80 + ((oc `shiftR` 6) .&. 0x3f)
, 0x80 + oc .&. 0x3f
]
bst = T.decodeUtf8With (\ _ -> fmap B.w2c)
parseTagsT :: B.ByteString -> [Tag T.Text]
parseTagsT = map textTag . parseTags
textTag (TagOpen t a) = TagOpen (bst t) [(bst n, bst v) | (n,v) <- a]
textTag (TagClose t) = TagClose (bst t)
textTag (TagText t) = TagText (bst t)
textTag (TagComment t) = TagComment (bst t)
textTag (TagWarning t) = TagWarning (bst t)
textTag (TagPosition r c) = TagPosition r c
escapeHtmlT :: T.Text -> T.Text
escapeHtmlT s
| not $ T.any (\ c -> c=='&'||c=='<'||c=='>'||c=='\''||c=='"') s = s
| otherwise = bst $ escapeHtml $ T.encodeUtf8 s
escapeHtml :: B.ByteString -> B.ByteString
escapeHtml s
| Nothing <- B8.find (\ c -> c=="&"||c=="<"||c==">"||c=="'"||c=="\"") s = s
| B.length s' == 0 = s
| otherwise = s'
where s' = B.inlinePerformIO $ withForeignPtr fp $ \ src ->
B.createAndTrim (len*6) $ \ dst -> do
(ch, dst') <- go (src `plusPtr` offset) dst len False
return $ if ch then dst' `minusPtr` dst else 0
(fp, offset, len) = B.toForeignPtr s
go :: P -> P -> Int -> Bool -> IO (Bool, P)
go !s !d !0 !c = return (c, d)
go !s !d !l !c
| r s == "&" = add s d l $ map B.c2w "&"
| r s == "<" = add s d l $ map B.c2w "<"
| r s == ">" = add s d l $ map B.c2w ">"
| r s == "'" = add s d l $ map B.c2w "'"
| r s == "\"" = add s d l $ map B.c2w """
| otherwise =
poke d (r s) >> go (pp s) (pp d) (mm l) c
add !s !d !l [] = go (pp s) d (mm l) True
add !s !d !l (x:xs) = do
poke d x
add s (pp d) l xs
renderTags = renderTags' escapeHtml B.concat
renderTagsT = renderTags' escapeHtmlT T.concat
renderTags' escape concat = go []
where go acc [] = concat $ reverse acc
go acc (TagOpen "br" _ : TagClose "br" : ts) =
go ("<br/>" : acc) ts
go acc (TagOpen t as : ts) =
go (">" : renderAtts (reverse as) (t : "<" : acc)) ts
go acc (TagClose t : ts) =
go (">" : t : "</" : acc) ts
go acc (TagText t : ts) =
go (escape t : acc) ts
renderAtts [] r = r
renderAtts ((a,v):as) r =
"\"" : escape v : "=\"" : a : " " : renderAtts as r
ensureUtf8Xml s
| Right _ <- T.decodeUtf8' s = s
| otherwise =
case parseTags $ B.dropWhile isSpace s of
(TagOpen "?xml" attrs : _)
| Just enc <- lookup "encoding" attrs
, B.map toLower enc /= "utf-8" ->
unsafePerformIO $
(do
c <- ICU.open (toString enc) Nothing
let r = T.encodeUtf8 $ ICU.toUnicode c s
B.length r `seq` return r)
`E.catch`
\ (e :: E.SomeException) -> return s
_ -> s