%
-% (c) The GRASP/AQUA Project, Glasgow University, 1997-1998
+% (c) The University of Glasgow, 1997-2006
%
-\section{Fast strings}
-
-Compact representations of character strings with
-unique identifiers (hash-cons'ish).
-
\begin{code}
+{-
+FastString: A compact, hash-consed, representation of character strings.
+ Comparison is O(1), and you can get a Unique from them.
+ Generated by the FSLIT macro
+ Turn into SDoc with Outputable.ftext
+
+LitString: Just a wrapper for the Addr# of a C string (Ptr CChar).
+ Practically no operations
+ Outputing them is fast
+ Generated by the SLIT macro
+ Turn into SDoc with Outputable.ptext
+
+Use LitString unless you want the facilities of FastString
+-}
module FastString
(
+ -- * FastStrings
FastString(..), -- not abstract, for now.
- mkFastString, -- :: String -> FastString
- mkFastStringNarrow, -- :: String -> FastString
- mkFastSubString, -- :: Addr -> Int -> Int -> FastString
-
- mkFastString#, -- :: Addr# -> FastString
- mkFastSubStringBA#, -- :: ByteArray# -> Int# -> Int# -> FastString
-
- mkFastStringInt, -- :: [Int] -> FastString
-
- uniqueOfFS, -- :: FastString -> Int#
- lengthFS, -- :: FastString -> Int
- nullFastString, -- :: FastString -> Bool
+ -- ** Construction
+ mkFastString,
+ mkFastStringBytes,
+ mkFastStringForeignPtr,
+ mkFastString#,
+ mkZFastString,
+ mkZFastStringBytes,
+ -- ** Deconstruction
unpackFS, -- :: FastString -> String
- unpackIntFS, -- :: FastString -> [Int]
- appendFS, -- :: FastString -> FastString -> FastString
- headFS, -- :: FastString -> Char
- headIntFS, -- :: FastString -> Int
- tailFS, -- :: FastString -> FastString
- concatFS, -- :: [FastString] -> FastString
- consFS, -- :: Char -> FastString -> FastString
- indexFS, -- :: FastString -> Int -> Char
- nilFS, -- :: FastString
-
- hPutFS, -- :: Handle -> FastString -> IO ()
-
+ bytesFS, -- :: FastString -> [Word8]
+
+ -- ** Encoding
+ isZEncoded,
+ zEncodeFS,
+
+ -- ** Operations
+ uniqueOfFS,
+ lengthFS,
+ nullFS,
+ appendFS,
+ headFS,
+ tailFS,
+ concatFS,
+ consFS,
+ nilFS,
+
+ -- ** Outputing
+ hPutFS,
+
+ -- ** Internal
+ getFastStringTable,
+ hasZEncoding,
+
+ -- * LitStrings
LitString,
- mkLitString# -- :: Addr# -> LitString
+ mkLitString#,
+ strLength
) where
-- This #define suppresses the "import FastString" that
#define COMPILING_FAST_STRING
#include "HsVersions.h"
-#if __GLASGOW_HASKELL__ < 503
-import PrelIOBase ( IO(..) )
-#else
-import GHC.IOBase ( IO(..) )
-#endif
+import Encoding
-import PrimPacked
-import GLAEXTS
-import UNSAFE_IO ( unsafePerformIO )
-import MONAD_ST ( stToIO )
-import DATA_IOREF ( IORef, newIORef, readIORef, writeIORef )
+import Foreign
+import Foreign.C
+import GHC.Exts
+import System.IO.Unsafe ( unsafePerformIO )
+import Control.Monad.ST ( stToIO )
+import Data.IORef ( IORef, newIORef, readIORef, writeIORef )
+import System.IO ( hPutBuf )
+import Data.Maybe ( isJust )
-#if __GLASGOW_HASKELL__ < 503
-import PrelArr ( STArray(..), newSTArray )
-#else
import GHC.Arr ( STArray(..), newSTArray )
-#endif
+import GHC.IOBase ( IO(..) )
+import GHC.Ptr ( Ptr(..) )
-#if __GLASGOW_HASKELL__ >= 504
-import GHC.IOBase
-import GHC.Handle
-import Foreign.C
-#else
-import IOExts ( hPutBufBAFull )
-#endif
+#define hASH_TBL_SIZE 4091
-import IO
-import Char ( chr, ord )
-#define hASH_TBL_SIZE 993
-\end{code}
+{-|
+A 'FastString' is an array of bytes, hashed to support fast O(1)
+comparison. It is also associated with a character encoding, so that
+we know how to convert a 'FastString' to the local encoding, or to the
+Z-encoding used by the compiler internally.
-@FastString@s are packed representations of strings
-with a unique id for fast comparisons. The unique id
-is assigned when creating the @FastString@, using
-a hash table to map from the character string representation
-to the unique ID.
+'FastString's support a memoized conversion to the Z-encoding via zEncodeFS.
+-}
-\begin{code}
-data FastString
- = FastString -- packed repr. on the heap.
- Int# -- unique id
- -- 0 => string literal, comparison
- -- will
- Int# -- length
- ByteArray# -- stuff
-
- | UnicodeStr -- if contains characters outside '\1'..'\xFF'
- Int# -- unique id
- [Int] -- character numbers
+data FastString = FastString {
+ uniq :: {-# UNPACK #-} !Int, -- unique id
+ n_bytes :: {-# UNPACK #-} !Int, -- number of bytes
+ n_chars :: {-# UNPACK #-} !Int, -- number of chars
+ buf :: {-# UNPACK #-} !(ForeignPtr Word8),
+ enc :: FSEncoding
+ }
-instance Eq FastString where
- -- shortcut for real FastStrings
- (FastString u1 _ _) == (FastString u2 _ _) = u1 ==# u2
- a == b = case cmpFS a b of { LT -> False; EQ -> True; GT -> False }
+data FSEncoding
+ = ZEncoded
+ -- including strings that don't need any encoding
+ | UTF8Encoded {-# UNPACK #-} !(IORef (Maybe FastString))
+ -- A UTF-8 string with a memoized Z-encoding
- (FastString u1 _ _) /= (FastString u2 _ _) = u1 /=# u2
- a /= b = case cmpFS a b of { LT -> True; EQ -> False; GT -> True }
+instance Eq FastString where
+ f1 == f2 = uniq f1 == uniq f2
instance Ord FastString where
+ -- Compares lexicographically, not by unique
a <= b = case cmpFS a b of { LT -> True; EQ -> True; GT -> False }
a < b = case cmpFS a b of { LT -> True; EQ -> False; GT -> False }
a >= b = case cmpFS a b of { LT -> False; EQ -> True; GT -> True }
| otherwise = y
compare a b = cmpFS a b
-lengthFS :: FastString -> Int
-lengthFS (FastString _ l# _) = I# l#
-lengthFS (UnicodeStr _ s) = length s
-
-nullFastString :: FastString -> Bool
-nullFastString (FastString _ l# _) = l# ==# 0#
-nullFastString (UnicodeStr _ []) = True
-nullFastString (UnicodeStr _ (_:_)) = False
-
-unpackFS :: FastString -> String
-unpackFS (FastString _ l# ba#) = unpackNBytesBA (BA ba#) (I# l#)
-unpackFS (UnicodeStr _ s) = map chr s
-
-unpackIntFS :: FastString -> [Int]
-unpackIntFS (UnicodeStr _ s) = s
-unpackIntFS fs = map ord (unpackFS fs)
-
-appendFS :: FastString -> FastString -> FastString
-appendFS fs1 fs2 = mkFastStringInt (unpackIntFS fs1 ++ unpackIntFS fs2)
+instance Show FastString where
+ show fs = show (unpackFS fs)
-concatFS :: [FastString] -> FastString
-concatFS ls = mkFastStringInt (concat (map unpackIntFS ls)) -- ToDo: do better
-
-headFS :: FastString -> Char
-headFS (FastString _ l# ba#) =
- if l# ># 0# then C# (indexCharArray# ba# 0#) else error ("headFS: empty FS")
-headFS (UnicodeStr _ (c:_)) = chr c
-headFS (UnicodeStr _ []) = error ("headFS: empty FS")
-
-headIntFS :: FastString -> Int
-headIntFS (UnicodeStr _ (c:_)) = c
-headIntFS fs = ord (headFS fs)
-
-indexFS :: FastString -> Int -> Char
-indexFS f i@(I# i#) =
- case f of
- FastString _ l# ba#
- | l# ># 0# && l# ># i# -> C# (indexCharArray# ba# i#)
- | otherwise -> error (msg (I# l#))
- UnicodeStr _ s -> chr (s!!i)
- where
- msg l = "indexFS: out of range: " ++ show (l,i)
-
-tailFS :: FastString -> FastString
-tailFS (FastString _ l# ba#) = mkFastSubStringBA# ba# 1# (l# -# 1#)
-tailFS fs = mkFastStringInt (tail (unpackIntFS fs))
-
-consFS :: Char -> FastString -> FastString
-consFS c fs = mkFastStringInt (ord c : unpackIntFS fs)
-
-uniqueOfFS :: FastString -> Int#
-uniqueOfFS (FastString u# _ _) = u#
-uniqueOfFS (UnicodeStr u# _) = u#
+cmpFS :: FastString -> FastString -> Ordering
+cmpFS (FastString u1 l1 _ buf1 _) (FastString u2 l2 _ buf2 _) =
+ if u1 == u2 then EQ else
+ let l = if l1 <= l2 then l1 else l2 in
+ inlinePerformIO $
+ withForeignPtr buf1 $ \p1 ->
+ withForeignPtr buf2 $ \p2 -> do
+ res <- memcmp p1 p2 l
+ case () of
+ _ | res < 0 -> return LT
+ | res == 0 -> if l1 == l2 then return EQ
+ else if l1 < l2 then return LT
+ else return GT
+ | otherwise -> return GT
+
+#ifndef __HADDOCK__
+foreign import ccall unsafe "ghc_memcmp"
+ memcmp :: Ptr a -> Ptr b -> Int -> IO Int
+#endif
-nilFS = mkFastString ""
-\end{code}
+-- -----------------------------------------------------------------------------
+-- Construction
+{-
Internally, the compiler will maintain a fast string symbol
table, providing sharing and fast comparison. Creation of
new @FastString@s then covertly does a lookup, re-using the
@FastString@ if there was a hit.
+-}
-Caution: mkFastStringUnicode assumes that if the string is in the
-table, it sits under the UnicodeStr constructor. Other mkFastString
-variants analogously assume the FastString constructor.
-
-\begin{code}
data FastStringTable =
FastStringTable
- Int#
+ {-# UNPACK #-} !Int
(MutableArray# RealWorld [FastString])
-type FastStringTableVar = IORef FastStringTable
-
-string_table :: FastStringTableVar
+string_table :: IORef FastStringTable
string_table =
- unsafePerformIO (
- stToIO (newSTArray (0::Int,hASH_TBL_SIZE) [])
- >>= \ (STArray _ _ arr#) ->
- newIORef (FastStringTable 0# arr#))
-
-lookupTbl :: FastStringTable -> Int# -> IO [FastString]
-lookupTbl (FastStringTable _ arr#) i# =
- IO ( \ s# ->
- readArray# arr# i# s#)
-
-updTbl :: FastStringTableVar -> FastStringTable -> Int# -> [FastString] -> IO ()
-updTbl fs_table_var (FastStringTable uid# arr#) i# ls =
- IO (\ s# -> case writeArray# arr# i# ls s# of { s2# ->
- (# s2#, () #) }) >>
- writeIORef fs_table_var (FastStringTable (uid# +# 1#) arr#)
+ unsafePerformIO $ do
+ (STArray _ _ arr#) <- stToIO (newSTArray (0::Int,hASH_TBL_SIZE) [])
+ newIORef (FastStringTable 0 arr#)
+
+lookupTbl :: FastStringTable -> Int -> IO [FastString]
+lookupTbl (FastStringTable _ arr#) (I# i#) =
+ IO $ \ s# -> readArray# arr# i# s#
+
+updTbl :: IORef FastStringTable -> FastStringTable -> Int -> [FastString] -> IO ()
+updTbl fs_table_var (FastStringTable uid arr#) (I# i#) ls = do
+ (IO $ \ s# -> case writeArray# arr# i# ls s# of { s2# -> (# s2#, () #) })
+ writeIORef fs_table_var (FastStringTable (uid+1) arr#)
mkFastString# :: Addr# -> FastString
-mkFastString# a# =
- case strLength (Ptr a#) of { (I# len#) -> mkFastStringLen# a# len# }
+mkFastString# a# = mkFastStringBytes ptr (strLength ptr)
+ where ptr = Ptr a#
-mkFastStringLen# :: Addr# -> Int# -> FastString
-mkFastStringLen# a# len# =
- unsafePerformIO (
- readIORef string_table >>= \ ft@(FastStringTable uid# tbl#) ->
+mkFastStringBytes :: Ptr Word8 -> Int -> FastString
+mkFastStringBytes ptr len = unsafePerformIO $ do
+ ft@(FastStringTable uid tbl#) <- readIORef string_table
let
- h = hashStr a# len#
- in
--- _trace ("hashed: "++show (I# h)) $
- lookupTbl ft h >>= \ lookup_result ->
+ h = hashStr ptr len
+ add_it ls = do
+ fs <- copyNewFastString uid ptr len
+ updTbl string_table ft h (fs:ls)
+ {- _trace ("new: " ++ show f_str) $ -}
+ return fs
+ --
+ lookup_result <- lookupTbl ft h
case lookup_result of
- [] ->
- -- no match, add it to table by copying out the
- -- the string into a ByteArray
- -- _trace "empty bucket" $
- case copyPrefixStr a# (I# len#) of
- BA barr# ->
- let f_str = FastString uid# len# barr# in
- updTbl string_table ft h [f_str] >>
- ({- _trace ("new: " ++ show f_str) $ -} return f_str)
- ls ->
- -- non-empty `bucket', scan the list looking
- -- entry with same length and compare byte by byte.
- -- _trace ("non-empty bucket"++show ls) $
- case bucket_match ls len# a# of
- Nothing ->
- case copyPrefixStr a# (I# len#) of
- BA barr# ->
- let f_str = FastString uid# len# barr# in
- updTbl string_table ft h (f_str:ls) >>
- ( {- _trace ("new: " ++ show f_str) $ -} return f_str)
- Just v -> {- _trace ("re-use: "++show v) $ -} return v)
- where
- bucket_match [] _ _ = Nothing
- bucket_match (v@(FastString _ l# ba#):ls) len# a# =
- if len# ==# l# && eqStrPrefix a# ba# l# then
- Just v
- else
- bucket_match ls len# a#
- bucket_match (UnicodeStr _ _ : ls) len# a# =
- bucket_match ls len# a#
-
-mkFastSubStringBA# :: ByteArray# -> Int# -> Int# -> FastString
-mkFastSubStringBA# barr# start# len# =
- unsafePerformIO (
- readIORef string_table >>= \ ft@(FastStringTable uid# tbl#) ->
+ [] -> add_it []
+ ls -> do
+ b <- bucket_match ls len ptr
+ case b of
+ Nothing -> add_it ls
+ Just v -> {- _trace ("re-use: "++show v) $ -} return v
+
+mkZFastStringBytes :: Ptr Word8 -> Int -> FastString
+mkZFastStringBytes ptr len = unsafePerformIO $ do
+ ft@(FastStringTable uid tbl#) <- readIORef string_table
let
- h = hashSubStrBA barr# start# len#
- in
--- _trace ("hashed(b): "++show (I# h)) $
- lookupTbl ft h >>= \ lookup_result ->
+ h = hashStr ptr len
+ add_it ls = do
+ fs <- copyNewZFastString uid ptr len
+ updTbl string_table ft h (fs:ls)
+ {- _trace ("new: " ++ show f_str) $ -}
+ return fs
+ --
+ lookup_result <- lookupTbl ft h
case lookup_result of
- [] ->
- -- no match, add it to table by copying out the
- -- the string into a ByteArray
- -- _trace "empty bucket(b)" $
- case copySubStrBA (BA barr#) (I# start#) (I# len#) of
- BA ba# ->
- let f_str = FastString uid# len# ba# in
- updTbl string_table ft h [f_str] >>
- -- _trace ("new(b): " ++ show f_str) $
- return f_str
- ls ->
- -- non-empty `bucket', scan the list looking
- -- entry with same length and compare byte by byte.
- -- _trace ("non-empty bucket(b)"++show ls) $
- case bucket_match ls start# len# barr# of
- Nothing ->
- case copySubStrBA (BA barr#) (I# start#) (I# len#) of
- BA ba# ->
- let f_str = FastString uid# len# ba# in
- updTbl string_table ft h (f_str:ls) >>
- -- _trace ("new(b): " ++ show f_str) $
- return f_str
- Just v ->
- -- _trace ("re-use(b): "++show v) $
- return v
- )
- where
- bucket_match [] _ _ _ = Nothing
- bucket_match (v:ls) start# len# ba# =
- case v of
- FastString _ l# barr# ->
- if len# ==# l# && eqStrPrefixBA barr# ba# start# len# then
- Just v
- else
- bucket_match ls start# len# ba#
- UnicodeStr _ _ -> bucket_match ls start# len# ba#
-
-mkFastStringUnicode :: [Int] -> FastString
-mkFastStringUnicode s =
- unsafePerformIO (
- readIORef string_table >>= \ ft@(FastStringTable uid# tbl#) ->
+ [] -> add_it []
+ ls -> do
+ b <- bucket_match ls len ptr
+ case b of
+ Nothing -> add_it ls
+ Just v -> {- _trace ("re-use: "++show v) $ -} return v
+
+-- | Create a 'FastString' from an existing 'ForeignPtr'; the difference
+-- between this and 'mkFastStringBytes' is that we don't have to copy
+-- the bytes if the string is new to the table.
+mkFastStringForeignPtr :: Ptr Word8 -> ForeignPtr Word8 -> Int -> IO FastString
+mkFastStringForeignPtr ptr fp len = do
+ ft@(FastStringTable uid tbl#) <- readIORef string_table
+-- _trace ("hashed: "++show (I# h)) $
let
- h = hashUnicode s
- in
--- _trace ("hashed(b): "++show (I# h)) $
- lookupTbl ft h >>= \ lookup_result ->
+ h = hashStr ptr len
+ add_it ls = do
+ fs <- mkNewFastString uid ptr fp len
+ updTbl string_table ft h (fs:ls)
+ {- _trace ("new: " ++ show f_str) $ -}
+ return fs
+ --
+ lookup_result <- lookupTbl ft h
+ case lookup_result of
+ [] -> add_it []
+ ls -> do
+ b <- bucket_match ls len ptr
+ case b of
+ Nothing -> add_it ls
+ Just v -> {- _trace ("re-use: "++show v) $ -} return v
+
+mkZFastStringForeignPtr :: Ptr Word8 -> ForeignPtr Word8 -> Int -> IO FastString
+mkZFastStringForeignPtr ptr fp len = do
+ ft@(FastStringTable uid tbl#) <- readIORef string_table
+-- _trace ("hashed: "++show (I# h)) $
+ let
+ h = hashStr ptr len
+ add_it ls = do
+ fs <- mkNewZFastString uid ptr fp len
+ updTbl string_table ft h (fs:ls)
+ {- _trace ("new: " ++ show f_str) $ -}
+ return fs
+ --
+ lookup_result <- lookupTbl ft h
case lookup_result of
- [] ->
- -- no match, add it to table by copying out the
- -- the string into a [Int]
- let f_str = UnicodeStr uid# s in
- updTbl string_table ft h [f_str] >>
- -- _trace ("new(b): " ++ show f_str) $
- return f_str
- ls ->
- -- non-empty `bucket', scan the list looking
- -- entry with same length and compare byte by byte.
- -- _trace ("non-empty bucket(b)"++show ls) $
- case bucket_match ls of
- Nothing ->
- let f_str = UnicodeStr uid# s in
- updTbl string_table ft h (f_str:ls) >>
- -- _trace ("new(b): " ++ show f_str) $
- return f_str
- Just v ->
- -- _trace ("re-use(b): "++show v) $
- return v
- )
- where
- bucket_match [] = Nothing
- bucket_match (v@(UnicodeStr _ s'):ls) =
- if s' == s then Just v else bucket_match ls
- bucket_match (FastString _ _ _ : ls) = bucket_match ls
-
-mkFastStringNarrow :: String -> FastString
-mkFastStringNarrow str =
- case packString str of { (I# len#, BA frozen#) ->
- mkFastSubStringBA# frozen# 0# len#
- }
- {- 0-indexed array, len# == index to one beyond end of string,
- i.e., (0,1) => empty string. -}
+ [] -> add_it []
+ ls -> do
+ b <- bucket_match ls len ptr
+ case b of
+ Nothing -> add_it ls
+ Just v -> {- _trace ("re-use: "++show v) $ -} return v
-mkFastString :: String -> FastString
-mkFastString str = if all good str
- then mkFastStringNarrow str
- else mkFastStringUnicode (map ord str)
- where
- good c = c >= '\1' && c <= '\xFF'
-
-mkFastStringInt :: [Int] -> FastString
-mkFastStringInt str = if all good str
- then mkFastStringNarrow (map chr str)
- else mkFastStringUnicode str
- where
- good c = c >= 1 && c <= 0xFF
-
-mkFastSubString :: Addr# -> Int -> Int -> FastString
-mkFastSubString a# (I# start#) (I# len#) =
- mkFastStringLen# (a# `plusAddr#` start#) len#
-\end{code}
-\begin{code}
-hashStr :: Addr# -> Int# -> Int#
+-- | Creates a UTF-8 encoded 'FastString' from a 'String'
+mkFastString :: String -> FastString
+mkFastString str =
+ inlinePerformIO $ do
+ let l = utf8EncodedLength str
+ buf <- mallocForeignPtrBytes l
+ withForeignPtr buf $ \ptr -> do
+ utf8EncodeString ptr str
+ mkFastStringForeignPtr ptr buf l
+
+
+-- | Creates a Z-encoded 'FastString' from a 'String'
+mkZFastString :: String -> FastString
+mkZFastString str =
+ inlinePerformIO $ do
+ let l = Prelude.length str
+ buf <- mallocForeignPtrBytes l
+ withForeignPtr buf $ \ptr -> do
+ pokeCAString (castPtr ptr) str
+ mkZFastStringForeignPtr ptr buf l
+
+bucket_match [] _ _ = return Nothing
+bucket_match (v@(FastString _ l _ buf _):ls) len ptr
+ | len == l = do
+ b <- cmpStringPrefix ptr buf len
+ if b then return (Just v)
+ else bucket_match ls len ptr
+ | otherwise =
+ bucket_match ls len ptr
+
+mkNewFastString uid ptr fp len = do
+ ref <- newIORef Nothing
+ n_chars <- countUTF8Chars ptr len
+ return (FastString uid len n_chars fp (UTF8Encoded ref))
+
+mkNewZFastString uid ptr fp len = do
+ return (FastString uid len len fp ZEncoded)
+
+
+copyNewFastString uid ptr len = do
+ fp <- copyBytesToForeignPtr ptr len
+ ref <- newIORef Nothing
+ n_chars <- countUTF8Chars ptr len
+ return (FastString uid len n_chars fp (UTF8Encoded ref))
+
+copyNewZFastString uid ptr len = do
+ fp <- copyBytesToForeignPtr ptr len
+ return (FastString uid len len fp ZEncoded)
+
+
+copyBytesToForeignPtr ptr len = do
+ fp <- mallocForeignPtrBytes len
+ withForeignPtr fp $ \ptr' -> copyBytes ptr' ptr len
+ return fp
+
+cmpStringPrefix :: Ptr Word8 -> ForeignPtr Word8 -> Int -> IO Bool
+cmpStringPrefix ptr fp len =
+ withForeignPtr fp $ \ptr' -> do
+ r <- memcmp ptr ptr' len
+ return (r == 0)
+
+
+hashStr :: Ptr Word8 -> Int -> Int
-- use the Addr to produce a hash value between 0 & m (inclusive)
-hashStr a# len# =
- case len# of
- 0# -> 0#
- 1# -> ((ord# c0 *# 631#) +# len#) `remInt#` hASH_TBL_SIZE#
- 2# -> ((ord# c0 *# 631#) +# (ord# c1 *# 217#) +# len#) `remInt#` hASH_TBL_SIZE#
- _ -> ((ord# c0 *# 631#) +# (ord# c1 *# 217#) +# (ord# c2 *# 43#) +# len#) `remInt#` hASH_TBL_SIZE#
- where
- c0 = indexCharOffAddr# a# 0#
- c1 = indexCharOffAddr# a# (len# `quotInt#` 2# -# 1#)
- c2 = indexCharOffAddr# a# (len# -# 1#)
-{-
- c1 = indexCharOffAddr# a# 1#
- c2 = indexCharOffAddr# a# 2#
--}
+hashStr (Ptr a#) (I# len#) = loop 0# 0#
+ where
+ loop h n | n ==# len# = I# h
+ | otherwise = loop h2 (n +# 1#)
+ where c = ord# (indexCharOffAddr# a# n)
+ h2 = (c +# (h *# 128#)) `remInt#` hASH_TBL_SIZE#
-hashSubStrBA :: ByteArray# -> Int# -> Int# -> Int#
- -- use the byte array to produce a hash value between 0 & m (inclusive)
-hashSubStrBA ba# start# len# =
- case len# of
- 0# -> 0#
- 1# -> ((ord# c0 *# 631#) +# len#) `remInt#` hASH_TBL_SIZE#
- 2# -> ((ord# c0 *# 631#) +# (ord# c1 *# 217#) +# len#) `remInt#` hASH_TBL_SIZE#
- _ -> ((ord# c0 *# 631#) +# (ord# c1 *# 217#) +# (ord# c2 *# 43#) +# len#) `remInt#` hASH_TBL_SIZE#
- where
- c0 = indexCharArray# ba# 0#
- c1 = indexCharArray# ba# (len# `quotInt#` 2# -# 1#)
- c2 = indexCharArray# ba# (len# -# 1#)
-
--- c1 = indexCharArray# ba# 1#
--- c2 = indexCharArray# ba# 2#
-
-hashUnicode :: [Int] -> Int#
- -- use the Addr to produce a hash value between 0 & m (inclusive)
-hashUnicode [] = 0#
-hashUnicode [I# c0] = ((c0 *# 631#) +# 1#) `remInt#` hASH_TBL_SIZE#
-hashUnicode [I# c0, I# c1] = ((c0 *# 631#) +# (c1 *# 217#) +# 2#) `remInt#` hASH_TBL_SIZE#
-hashUnicode s = ((c0 *# 631#) +# (c1 *# 217#) +# (c2 *# 43#) +# len#) `remInt#` hASH_TBL_SIZE#
- where
- I# len# = length s
- I# c0 = s !! 0
- I# c1 = s !! (I# (len# `quotInt#` 2# -# 1#))
- I# c2 = s !! (I# (len# -# 1#))
+-- -----------------------------------------------------------------------------
+-- Operations
-\end{code}
+-- | Returns the length of the 'FastString' in characters
+lengthFS :: FastString -> Int
+lengthFS f = n_chars f
+
+-- | Returns 'True' if the 'FastString' is Z-encoded
+isZEncoded :: FastString -> Bool
+isZEncoded fs | ZEncoded <- enc fs = True
+ | otherwise = False
+
+-- | Returns 'True' if this 'FastString' is not Z-encoded but already has
+-- a Z-encoding cached (used in producing stats).
+hasZEncoding :: FastString -> Bool
+hasZEncoding fs@(FastString uid n_bytes _ fp enc) =
+ case enc of
+ ZEncoded -> False
+ UTF8Encoded ref ->
+ inlinePerformIO $ do
+ m <- readIORef ref
+ return (isJust m)
+
+-- | Returns 'True' if the 'FastString' is empty
+nullFS :: FastString -> Bool
+nullFS f = n_bytes f == 0
+
+-- | unpacks and decodes the FastString
+unpackFS :: FastString -> String
+unpackFS (FastString _ n_bytes _ buf enc) =
+ inlinePerformIO $ withForeignPtr buf $ \ptr ->
+ case enc of
+ ZEncoded -> peekCAStringLen (castPtr ptr,n_bytes)
+ UTF8Encoded _ -> utf8DecodeString ptr n_bytes
+
+bytesFS :: FastString -> [Word8]
+bytesFS (FastString _ n_bytes _ buf enc) =
+ inlinePerformIO $ withForeignPtr buf $ \ptr ->
+ peekArray n_bytes ptr
+
+-- | returns a Z-encoded version of a 'FastString'. This might be the
+-- original, if it was already Z-encoded. The first time this
+-- function is applied to a particular 'FastString', the results are
+-- memoized.
+--
+zEncodeFS :: FastString -> FastString
+zEncodeFS fs@(FastString uid n_bytes _ fp enc) =
+ case enc of
+ ZEncoded -> fs
+ UTF8Encoded ref ->
+ inlinePerformIO $ do
+ m <- readIORef ref
+ case m of
+ Just fs -> return fs
+ Nothing -> do
+ let efs = mkZFastString (zEncodeString (unpackFS fs))
+ writeIORef ref (Just efs)
+ return efs
-\begin{code}
-cmpFS :: FastString -> FastString -> Ordering
-cmpFS (UnicodeStr u1# s1) (UnicodeStr u2# s2) = if u1# ==# u2# then EQ
- else compare s1 s2
-cmpFS (UnicodeStr _ s1) s2 = compare s1 (unpackIntFS s2)
-cmpFS s1 (UnicodeStr _ s2) = compare (unpackIntFS s1) s2
-cmpFS (FastString u1# l1# b1#) (FastString u2# l2# b2#) =
- if u1# ==# u2# then EQ else
- let l# = if l1# <=# l2# then l1# else l2# in
- unsafePerformIO (
- memcmp b1# b2# l# >>= \ (I# res) ->
- return (
- if res <# 0# then LT
- else if res ==# 0# then
- if l1# ==# l2# then EQ
- else if l1# <# l2# then LT else GT
- else GT
- ))
-
-foreign import ccall "ghc_memcmp" unsafe
- memcmp :: ByteArray# -> ByteArray# -> Int# -> IO Int
+appendFS :: FastString -> FastString -> FastString
+appendFS fs1 fs2 = mkFastString (unpackFS fs1 ++ unpackFS fs2)
+
+concatFS :: [FastString] -> FastString
+concatFS ls = mkFastString (Prelude.concat (map unpackFS ls)) -- ToDo: do better
+
+headFS :: FastString -> Char
+headFS (FastString _ n_bytes _ buf enc) =
+ inlinePerformIO $ withForeignPtr buf $ \ptr -> do
+ case enc of
+ ZEncoded -> do
+ w <- peek (castPtr ptr)
+ return (castCCharToChar w)
+ UTF8Encoded _ ->
+ return (fst (utf8DecodeChar ptr))
+
+tailFS :: FastString -> FastString
+tailFS (FastString _ n_bytes _ buf enc) =
+ inlinePerformIO $ withForeignPtr buf $ \ptr -> do
+ case enc of
+ ZEncoded -> do
+ return $! mkZFastStringBytes (ptr `plusPtr` 1) (n_bytes - 1)
+ UTF8Encoded _ -> do
+ let (_,ptr') = utf8DecodeChar ptr
+ let off = ptr' `minusPtr` ptr
+ return $! mkFastStringBytes (ptr `plusPtr` off) (n_bytes - off)
+
+consFS :: Char -> FastString -> FastString
+consFS c fs = mkFastString (c : unpackFS fs)
+
+uniqueOfFS :: FastString -> Int#
+uniqueOfFS (FastString (I# u#) _ _ _ _) = u#
+
+nilFS = mkFastString ""
-- -----------------------------------------------------------------------------
--- Outputting 'FastString's
+-- Stats
-#if __GLASGOW_HASKELL__ >= 504
-
--- this is our own version of hPutBuf for FastStrings, because in
--- 5.04+ we don't have mutable byte arrays and therefore hPutBufBA.
--- The closest is hPutArray in Data.Array.IO, but that does some extra
--- range checks that we want to avoid here.
-
-foreign import ccall unsafe "__hscore_memcpy_dst_off"
- memcpy_baoff_ba :: RawBuffer -> Int -> RawBuffer -> CSize -> IO (Ptr ())
-
-hPutFS handle (FastString _ l# ba#)
- | l# ==# 0# = return ()
- | otherwise
- = do wantWritableHandle "hPutFS" handle $
- \ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=stream } -> do
-
- old_buf@Buffer{ bufBuf=old_raw, bufRPtr=r, bufWPtr=w, bufSize=size }
- <- readIORef ref
-
- let count = I# l#
- raw = unsafeCoerce# ba# :: MutableByteArray# RealWorld
-
- -- enough room in handle buffer?
- if (size - w > count)
- -- There's enough room in the buffer:
- -- just copy the data in and update bufWPtr.
- then do memcpy_baoff_ba old_raw w raw (fromIntegral count)
- writeIORef ref old_buf{ bufWPtr = w + count }
- return ()
-
- -- else, we have to flush
- else do flushed_buf <- flushWriteBuffer fd stream old_buf
- writeIORef ref flushed_buf
- let this_buf =
- Buffer{ bufBuf=raw, bufState=WriteBuffer,
- bufRPtr=0, bufWPtr=count, bufSize=count }
- flushWriteBuffer fd stream this_buf
- return ()
-
-#else
-
-hPutFS :: Handle -> FastString -> IO ()
-hPutFS handle (FastString _ l# ba#)
- | l# ==# 0# = return ()
- | otherwise = do mba <- stToIO $ unsafeThawByteArray (ByteArray (bot::Int) bot ba#)
- hPutBufBAFull handle mba (I# l#)
- where
- bot = error "hPutFS.ba"
+getFastStringTable :: IO [[FastString]]
+getFastStringTable = do
+ tbl <- readIORef string_table
+ buckets <- mapM (lookupTbl tbl) [0 .. hASH_TBL_SIZE]
+ return buckets
-#endif
+-- -----------------------------------------------------------------------------
+-- Outputting 'FastString's
+
+-- |Outputs a 'FastString' with /no decoding at all/, that is, you
+-- get the actual bytes in the 'FastString' written to the 'Handle'.
+hPutFS handle (FastString _ len _ fp _)
+ | len == 0 = return ()
+ | otherwise = do withForeignPtr fp $ \ptr -> hPutBuf handle ptr len
--- ONLY here for debugging the NCG (so -ddump-stix works for string
--- literals); no idea if this is really necessary. JRS, 010131
-hPutFS handle (UnicodeStr _ is)
- = hPutStr handle ("(UnicodeStr " ++ show is ++ ")")
+-- ToDo: we'll probably want an hPutFSLocal, or something, to output
+-- in the current locale's encoding (for error messages and suchlike).
-- -----------------------------------------------------------------------------
-- LitStrings, here for convenience only.
type LitString = Ptr ()
--- ToDo: make it a Ptr when we don't have to support 4.08 any more
mkLitString# :: Addr# -> LitString
mkLitString# a# = Ptr a#
+
+foreign import ccall unsafe "ghc_strlen"
+ strLength :: Ptr () -> Int
+
+-- -----------------------------------------------------------------------------
+-- under the carpet
+
+-- Just like unsafePerformIO, but we inline it.
+{-# INLINE inlinePerformIO #-}
+inlinePerformIO :: IO a -> a
+inlinePerformIO (IO m) = case m realWorld# of (# _, r #) -> r
+
+-- NB. does *not* add a '\0'-terminator.
+pokeCAString :: Ptr CChar -> String -> IO ()
+pokeCAString ptr str =
+ let
+ go [] n = return ()
+ go (c:cs) n = do pokeElemOff ptr n (castCharToCChar c); go cs (n+1)
+ in
+ go str 0
+
+#if __GLASGOW_HASKELL__ < 600
+
+mallocForeignPtrBytes :: Int -> IO (ForeignPtr a)
+mallocForeignPtrBytes n = do
+ r <- mallocBytes n
+ newForeignPtr r (finalizerFree r)
+
+foreign import ccall unsafe "stdlib.h free"
+ finalizerFree :: Ptr a -> IO ()
+
+peekCAStringLen = peekCStringLen
+
+#elif __GLASGOW_HASKELL__ <= 602
+
+peekCAStringLen = peekCStringLen
+
+#endif
\end{code}
projects / ghc-hetmet.git / blobdiff