{-# LANGUAGE CPP, ForeignFunctionInterface, BangPatterns #-}
{-# LANGUAGE UnliftedFFITypes, MagicHash,
            UnboxedTuples, DeriveDataTypeable #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE PatternSynonyms, ViewPatterns #-}
{-# LANGUAGE Unsafe #-}
{-# LANGUAGE TemplateHaskellQuotes #-}
{-# OPTIONS_HADDOCK not-home #-}

-- |
-- Module      : Data.ByteString.Internal
-- Copyright   : (c) Don Stewart 2006-2008
--               (c) Duncan Coutts 2006-2012
-- License     : BSD-style
-- Maintainer  : dons00@gmail.com, duncan@community.haskell.org
-- Stability   : unstable
-- Portability : non-portable
--
-- A module containing semi-public 'ByteString' internals. This exposes the
-- 'ByteString' representation and low level construction functions. As such
-- all the functions in this module are unsafe. The API is also not stable.
--
-- Where possible application should instead use the functions from the normal
-- public interface modules, such as "Data.ByteString.Unsafe". Packages that
-- extend the ByteString system at a low level will need to use this module.
--
module Data.ByteString.Internal (

        -- * The @ByteString@ type and representation
        ByteString
        ( BS
        , PS -- backwards compatibility shim
        ),

        StrictByteString,

        -- * Internal indexing
        findIndexOrLength,

        -- * Conversion with lists: packing and unpacking
        packBytes, packUptoLenBytes, unsafePackLenBytes,
        packChars, packUptoLenChars, unsafePackLenChars,
        unpackBytes, unpackAppendBytesLazy, unpackAppendBytesStrict,
        unpackChars, unpackAppendCharsLazy, unpackAppendCharsStrict,
        unsafePackAddress, unsafePackLenAddress,
        unsafePackLiteral, unsafePackLenLiteral,

        -- * Low level imperative construction
        empty,
        create,
        createUptoN,
        createUptoN',
        createAndTrim,
        createAndTrim',
        unsafeCreate,
        unsafeCreateUptoN,
        unsafeCreateUptoN',
        mallocByteString,

        -- * Conversion to and from ForeignPtrs
        fromForeignPtr,
        toForeignPtr,
        fromForeignPtr0,
        toForeignPtr0,

        -- * Utilities
        nullForeignPtr,
        checkedAdd,

        -- * Standard C Functions
        c_strlen,
        c_free_finalizer,

        memchr,
        memcmp,
        memcpy,
        memset,

        -- * cbits functions
        c_reverse,
        c_intersperse,
        c_maximum,
        c_minimum,
        c_count,
        c_sort,

        -- * Chars
        w2c, c2w, isSpaceWord8, isSpaceChar8,

        -- * Deprecated and unmentionable
        accursedUnutterablePerformIO,

        -- * Exported compatibility shim
        plusForeignPtr,
        unsafeWithForeignPtr
  ) where

import Prelude hiding (concat, null)
import qualified Data.List as List

import Control.Monad            (void)

import Foreign.ForeignPtr       (ForeignPtr, withForeignPtr)
import Foreign.Ptr              (Ptr, FunPtr, plusPtr, minusPtr)
import Foreign.Storable         (Storable(..))
import Foreign.C.Types          (CInt(..), CSize(..))
import Foreign.C.String         (CString)

#if MIN_VERSION_base(4,13,0)
import Data.Semigroup           (Semigroup (sconcat, stimes))
#else
import Data.Semigroup           (Semigroup ((<>), sconcat, stimes))
#endif
import Data.List.NonEmpty       (NonEmpty ((:|)))

import Control.DeepSeq          (NFData(rnf))

import Data.String              (IsString(..))

import Control.Exception        (assert)

import Data.Bits                ((.&.))
import Data.Char                (ord)
import Data.Word

import Data.Typeable            (Typeable)
import Data.Data                (Data(..), mkNoRepType)

import GHC.Base                 (nullAddr#,realWorld#,unsafeChr)
import GHC.Exts                 (IsList(..))
import GHC.CString              (unpackCString#)
import GHC.Prim                 (Addr#)
import GHC.IO                   (IO(IO),unsafeDupablePerformIO)
import GHC.ForeignPtr           (ForeignPtr(ForeignPtr)
#if __GLASGOW_HASKELL__ < 900
                                , newForeignPtr_
#endif
                                , mallocPlainForeignPtrBytes)

#if MIN_VERSION_base(4,10,0)
import GHC.ForeignPtr           (plusForeignPtr)
#else
import GHC.Prim                 (plusAddr#)
#endif

#if __GLASGOW_HASKELL__ >= 811
import GHC.CString              (cstringLength#)
import GHC.ForeignPtr           (ForeignPtrContents(FinalPtr))
#else
import GHC.Ptr                  (Ptr(..))
#endif

#if (__GLASGOW_HASKELL__ < 802) || (__GLASGOW_HASKELL__ >= 811)
import GHC.Types                (Int (..))
#endif

#if MIN_VERSION_base(4,15,0)
import GHC.ForeignPtr           (unsafeWithForeignPtr)
#endif

import qualified Language.Haskell.TH.Lib as TH
import qualified Language.Haskell.TH.Syntax as TH

#if !MIN_VERSION_base(4,15,0)
unsafeWithForeignPtr :: ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr = withForeignPtr
#endif

-- CFILES stuff is Hugs only
{-# CFILES cbits/fpstring.c #-}

#if !MIN_VERSION_base(4,10,0)
-- |Advances the given address by the given offset in bytes.
--
-- The new 'ForeignPtr' shares the finalizer of the original,
-- equivalent from a finalization standpoint to just creating another
-- reference to the original. That is, the finalizer will not be
-- called before the new 'ForeignPtr' is unreachable, nor will it be
-- called an additional time due to this call, and the finalizer will
-- be called with the same address that it would have had this call
-- not happened, *not* the new address.
plusForeignPtr :: ForeignPtr a -> Int -> ForeignPtr b
plusForeignPtr (ForeignPtr addr guts) (I# offset) = ForeignPtr (plusAddr# addr offset) guts
{-# INLINE [0] plusForeignPtr #-}
{-# RULES
"ByteString plusForeignPtr/0" forall fp .
   plusForeignPtr fp 0 = fp
 #-}
#endif

-- -----------------------------------------------------------------------------

-- | A space-efficient representation of a 'Word8' vector, supporting many
-- efficient operations.
--
-- A 'ByteString' contains 8-bit bytes, or by using the operations from
-- "Data.ByteString.Char8" it can be interpreted as containing 8-bit
-- characters.
--
data ByteString = BS {-# UNPACK #-} !(ForeignPtr Word8) -- payload
                     {-# UNPACK #-} !Int                -- length
                     -- ^ @since 0.11.0.0
    deriving (Typeable)

-- | Type synonym for the strict flavour of 'ByteString'.
--
-- @since 0.11.2.0
type StrictByteString = ByteString

-- |
-- @'PS' foreignPtr offset length@ represents a 'ByteString' with data
-- backed by a given @foreignPtr@, starting at a given @offset@ in bytes
-- and of a specified @length@.
--
-- This pattern is used to emulate the legacy 'ByteString' data
-- constructor, so that pre-existing code generally doesn't need to
-- change to benefit from the simplified 'BS' constructor and can
-- continue to function unchanged.
--
-- /Note:/ Matching with this constructor will always be given a 0 offset,
-- as the base will be manipulated by 'plusForeignPtr' instead.
--
pattern PS :: ForeignPtr Word8 -> Int -> Int -> ByteString
pattern $mPS :: forall {r}.
ByteString
-> (ForeignPtr Word8 -> Int -> Int -> r) -> ((# #) -> r) -> r
$bPS :: ForeignPtr Word8 -> Int -> Int -> ByteString
PS fp zero len <- BS fp ((0,) -> (zero, len)) where
  PS ForeignPtr Word8
fp Int
o Int
len = ForeignPtr Word8 -> Int -> ByteString
BS (forall a b. ForeignPtr a -> Int -> ForeignPtr b
plusForeignPtr ForeignPtr Word8
fp Int
o) Int
len
#if __GLASGOW_HASKELL__ >= 802
{-# COMPLETE PS #-}
#endif

instance Eq  ByteString where
    == :: ByteString -> ByteString -> Bool
(==)    = ByteString -> ByteString -> Bool
eq

instance Ord ByteString where
    compare :: ByteString -> ByteString -> Ordering
compare = ByteString -> ByteString -> Ordering
compareBytes

instance Semigroup ByteString where
    <> :: ByteString -> ByteString -> ByteString
(<>)    = ByteString -> ByteString -> ByteString
append
    sconcat :: NonEmpty ByteString -> ByteString
sconcat (ByteString
b:|[ByteString]
bs) = [ByteString] -> ByteString
concat (ByteString
bforall a. a -> [a] -> [a]
:[ByteString]
bs)
    stimes :: forall b. Integral b => b -> ByteString -> ByteString
stimes  = forall b. Integral b => b -> ByteString -> ByteString
times

instance Monoid ByteString where
    mempty :: ByteString
mempty  = ByteString
empty
    mappend :: ByteString -> ByteString -> ByteString
mappend = forall a. Semigroup a => a -> a -> a
(<>)
    mconcat :: [ByteString] -> ByteString
mconcat = [ByteString] -> ByteString
concat

instance NFData ByteString where
    rnf :: ByteString -> ()
rnf BS{} = ()

instance Show ByteString where
    showsPrec :: Int -> ByteString -> ShowS
showsPrec Int
p ByteString
ps String
r = forall a. Show a => Int -> a -> ShowS
showsPrec Int
p (ByteString -> String
unpackChars ByteString
ps) String
r

instance Read ByteString where
    readsPrec :: Int -> ReadS ByteString
readsPrec Int
p String
str = [ (String -> ByteString
packChars String
x, String
y) | (String
x, String
y) <- forall a. Read a => Int -> ReadS a
readsPrec Int
p String
str ]

-- | @since 0.10.12.0
instance IsList ByteString where
  type Item ByteString = Word8
  fromList :: [Item ByteString] -> ByteString
fromList = [Word8] -> ByteString
packBytes
  toList :: ByteString -> [Item ByteString]
toList   = ByteString -> [Word8]
unpackBytes

-- | Beware: 'fromString' truncates multi-byte characters to octets.
-- e.g. "枯朶に烏のとまりけり秋の暮" becomes �6k�nh~�Q��n�
instance IsString ByteString where
    {-# INLINE fromString #-}
    fromString :: String -> ByteString
fromString = String -> ByteString
packChars

instance Data ByteString where
  gfoldl :: forall (c :: * -> *).
(forall d b. Data d => c (d -> b) -> d -> c b)
-> (forall g. g -> c g) -> ByteString -> c ByteString
gfoldl forall d b. Data d => c (d -> b) -> d -> c b
f forall g. g -> c g
z ByteString
txt = forall g. g -> c g
z [Word8] -> ByteString
packBytes forall d b. Data d => c (d -> b) -> d -> c b
`f` ByteString -> [Word8]
unpackBytes ByteString
txt
  toConstr :: ByteString -> Constr
toConstr ByteString
_     = forall a. (?callStack::CallStack) => String -> a
error String
"Data.ByteString.ByteString.toConstr"
  gunfold :: forall (c :: * -> *).
(forall b r. Data b => c (b -> r) -> c r)
-> (forall r. r -> c r) -> Constr -> c ByteString
gunfold forall b r. Data b => c (b -> r) -> c r
_ forall r. r -> c r
_    = forall a. (?callStack::CallStack) => String -> a
error String
"Data.ByteString.ByteString.gunfold"
  dataTypeOf :: ByteString -> DataType
dataTypeOf ByteString
_   = String -> DataType
mkNoRepType String
"Data.ByteString.ByteString"

-- | @since 0.11.2.0
instance TH.Lift ByteString where
#if MIN_VERSION_template_haskell(2,16,0)
  lift :: forall (m :: * -> *). Quote m => ByteString -> m Exp
lift (BS ForeignPtr Word8
ptr Int
len) = [| unsafePackLenLiteral |]
    forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
`TH.appE` forall (m :: * -> *). Quote m => Lit -> m Exp
TH.litE (Integer -> Lit
TH.integerL (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
len))
    forall (m :: * -> *). Quote m => m Exp -> m Exp -> m Exp
`TH.appE` forall (m :: * -> *). Quote m => Lit -> m Exp
TH.litE (Bytes -> Lit
TH.BytesPrimL forall a b. (a -> b) -> a -> b
$ ForeignPtr Word8 -> Word -> Word -> Bytes
TH.Bytes ForeignPtr Word8
ptr Word
0 (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
len))
#else
  lift bs@(BS _ len) = [| unsafePackLenLiteral |]
    `TH.appE` TH.litE (TH.integerL (fromIntegral len))
    `TH.appE` TH.litE (TH.StringPrimL $ unpackBytes bs)
#endif

#if MIN_VERSION_template_haskell(2,17,0)
  liftTyped :: forall (m :: * -> *). Quote m => ByteString -> Code m ByteString
liftTyped = forall a (m :: * -> *). Quote m => m Exp -> Code m a
TH.unsafeCodeCoerce forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall t (m :: * -> *). (Lift t, Quote m) => t -> m Exp
TH.lift
#elif MIN_VERSION_template_haskell(2,16,0)
  liftTyped = TH.unsafeTExpCoerce . TH.lift
#endif

------------------------------------------------------------------------
-- Internal indexing

-- | 'findIndexOrLength' is a variant of findIndex, that returns the length
-- of the string if no element is found, rather than Nothing.
findIndexOrLength :: (Word8 -> Bool) -> ByteString -> Int
findIndexOrLength :: (Word8 -> Bool) -> ByteString -> Int
findIndexOrLength Word8 -> Bool
k (BS ForeignPtr Word8
x Int
l) =
    forall a. IO a -> a
accursedUnutterablePerformIO forall a b. (a -> b) -> a -> b
$ forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
x Ptr Word8 -> IO Int
g
  where
    g :: Ptr Word8 -> IO Int
g Ptr Word8
ptr = Int -> IO Int
go Int
0
      where
        go :: Int -> IO Int
go !Int
n | Int
n forall a. Ord a => a -> a -> Bool
>= Int
l    = forall (m :: * -> *) a. Monad m => a -> m a
return Int
l
              | Bool
otherwise = do Word8
w <- forall a. Storable a => Ptr a -> IO a
peek forall a b. (a -> b) -> a -> b
$ Ptr Word8
ptr forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
n
                               if Word8 -> Bool
k Word8
w
                                 then forall (m :: * -> *) a. Monad m => a -> m a
return Int
n
                                 else Int -> IO Int
go (Int
nforall a. Num a => a -> a -> a
+Int
1)
{-# INLINE findIndexOrLength #-}

------------------------------------------------------------------------
-- Packing and unpacking from lists

packBytes :: [Word8] -> ByteString
packBytes :: [Word8] -> ByteString
packBytes [Word8]
ws = Int -> [Word8] -> ByteString
unsafePackLenBytes (forall (t :: * -> *) a. Foldable t => t a -> Int
List.length [Word8]
ws) [Word8]
ws

packChars :: [Char] -> ByteString
packChars :: String -> ByteString
packChars String
cs = Int -> String -> ByteString
unsafePackLenChars (forall (t :: * -> *) a. Foldable t => t a -> Int
List.length String
cs) String
cs

{-# INLINE [0] packChars #-}

{-# RULES
"ByteString packChars/packAddress" forall s .
   packChars (unpackCString# s) = unsafePackLiteral s
 #-}

unsafePackLenBytes :: Int -> [Word8] -> ByteString
unsafePackLenBytes :: Int -> [Word8] -> ByteString
unsafePackLenBytes Int
len [Word8]
xs0 =
    Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
len forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> forall {b}. Storable b => Ptr b -> [b] -> IO ()
go Ptr Word8
p [Word8]
xs0
  where
    go :: Ptr b -> [b] -> IO ()
go !Ptr b
_ []     = forall (m :: * -> *) a. Monad m => a -> m a
return ()
    go !Ptr b
p (b
x:[b]
xs) = forall a. Storable a => Ptr a -> a -> IO ()
poke Ptr b
p b
x forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Ptr b -> [b] -> IO ()
go (Ptr b
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
1) [b]
xs

unsafePackLenChars :: Int -> [Char] -> ByteString
unsafePackLenChars :: Int -> String -> ByteString
unsafePackLenChars Int
len String
cs0 =
    Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
len forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> Ptr Word8 -> String -> IO ()
go Ptr Word8
p String
cs0
  where
    go :: Ptr Word8 -> String -> IO ()
go !Ptr Word8
_ []     = forall (m :: * -> *) a. Monad m => a -> m a
return ()
    go !Ptr Word8
p (Char
c:String
cs) = forall a. Storable a => Ptr a -> a -> IO ()
poke Ptr Word8
p (Char -> Word8
c2w Char
c) forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Ptr Word8 -> String -> IO ()
go (Ptr Word8
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
1) String
cs


-- | /O(n)/ Pack a null-terminated sequence of bytes, pointed to by an
-- Addr\# (an arbitrary machine address assumed to point outside the
-- garbage-collected heap) into a @ByteString@. A much faster way to
-- create an 'Addr#' is with an unboxed string literal, than to pack a
-- boxed string. A unboxed string literal is compiled to a static @char
-- []@ by GHC. Establishing the length of the string requires a call to
-- @strlen(3)@, so the 'Addr#' must point to a null-terminated buffer (as
-- is the case with @\"string\"\#@ literals in GHC). Use 'Data.ByteString.Unsafe.unsafePackAddressLen'
-- if you know the length of the string statically.
--
-- An example:
--
-- > literalFS = unsafePackAddress "literal"#
--
-- This function is /unsafe/. If you modify the buffer pointed to by the
-- original 'Addr#' this modification will be reflected in the resulting
-- @ByteString@, breaking referential transparency.
--
-- Note this also won't work if your 'Addr#' has embedded @\'\\0\'@ characters in
-- the string, as @strlen@ will return too short a length.
--
unsafePackAddress :: Addr# -> IO ByteString
unsafePackAddress :: Addr# -> IO ByteString
unsafePackAddress Addr#
addr# = do
#if __GLASGOW_HASKELL__ >= 811
    Int -> Addr# -> IO ByteString
unsafePackLenAddress (Int# -> Int
I# (Addr# -> Int#
cstringLength# Addr#
addr#)) Addr#
addr#
#else
    l <- c_strlen (Ptr addr#)
    unsafePackLenAddress (fromIntegral l) addr#
#endif
{-# INLINE unsafePackAddress #-}

-- | See 'unsafePackAddress'. This function is similar,
-- but takes an additional length argument rather then computing
-- it with @strlen@.
-- Therefore embedding @\'\\0\'@ characters is possible.
--
-- @since 0.11.2.0
unsafePackLenAddress :: Int -> Addr# -> IO ByteString
unsafePackLenAddress :: Int -> Addr# -> IO ByteString
unsafePackLenAddress Int
len Addr#
addr# = do
#if __GLASGOW_HASKELL__ >= 811
    forall (m :: * -> *) a. Monad m => a -> m a
return (ForeignPtr Word8 -> Int -> ByteString
BS (forall a. Addr# -> ForeignPtrContents -> ForeignPtr a
ForeignPtr Addr#
addr# ForeignPtrContents
FinalPtr) Int
len)
#else
    p <- newForeignPtr_ (Ptr addr#)
    return $ BS p len
#endif
{-# INLINE unsafePackLenAddress #-}

-- | See 'unsafePackAddress'. This function has similar behavior. Prefer
-- this function when the address in known to be an @Addr#@ literal. In
-- that context, there is no need for the sequencing guarantees that 'IO'
-- provides. On GHC 9.0 and up, this function uses the @FinalPtr@ data
-- constructor for @ForeignPtrContents@.
--
-- @since 0.11.1.0
unsafePackLiteral :: Addr# -> ByteString
unsafePackLiteral :: Addr# -> ByteString
unsafePackLiteral Addr#
addr# =
#if __GLASGOW_HASKELL__ >= 811
  Int -> Addr# -> ByteString
unsafePackLenLiteral (Int# -> Int
I# (Addr# -> Int#
cstringLength# Addr#
addr#)) Addr#
addr#
#else
  let len = accursedUnutterablePerformIO (c_strlen (Ptr addr#))
   in unsafePackLenLiteral (fromIntegral len) addr#
#endif
{-# INLINE unsafePackLiteral #-}


-- | See 'unsafePackLiteral'. This function is similar,
-- but takes an additional length argument rather then computing
-- it with @strlen@.
-- Therefore embedding @\'\\0\'@ characters is possible.
--
-- @since 0.11.2.0
unsafePackLenLiteral :: Int -> Addr# -> ByteString
unsafePackLenLiteral :: Int -> Addr# -> ByteString
unsafePackLenLiteral Int
len Addr#
addr# =
#if __GLASGOW_HASKELL__ >= 811
  ForeignPtr Word8 -> Int -> ByteString
BS (forall a. Addr# -> ForeignPtrContents -> ForeignPtr a
ForeignPtr Addr#
addr# ForeignPtrContents
FinalPtr) Int
len
#else
  BS (accursedUnutterablePerformIO (newForeignPtr_ (Ptr addr#))) len
#endif
{-# INLINE unsafePackLenLiteral #-}

packUptoLenBytes :: Int -> [Word8] -> (ByteString, [Word8])
packUptoLenBytes :: Int -> [Word8] -> (ByteString, [Word8])
packUptoLenBytes Int
len [Word8]
xs0 =
    forall a. Int -> (Ptr Word8 -> IO (Int, a)) -> (ByteString, a)
unsafeCreateUptoN' Int
len forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p0 ->
      let p_end :: Ptr Word8
p_end = forall a b. Ptr a -> Int -> Ptr b
plusPtr Ptr Word8
p0 Int
len
          go :: Ptr Word8 -> [Word8] -> IO (Int, [Word8])
go !Ptr Word8
p []              = forall (m :: * -> *) a. Monad m => a -> m a
return (Ptr Word8
p forall a b. Ptr a -> Ptr b -> Int
`minusPtr` Ptr Word8
p0, [])
          go !Ptr Word8
p [Word8]
xs | Ptr Word8
p forall a. Eq a => a -> a -> Bool
== Ptr Word8
p_end = forall (m :: * -> *) a. Monad m => a -> m a
return (Int
len, [Word8]
xs)
          go !Ptr Word8
p (Word8
x:[Word8]
xs)          = forall a. Storable a => Ptr a -> a -> IO ()
poke Ptr Word8
p Word8
x forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Ptr Word8 -> [Word8] -> IO (Int, [Word8])
go (Ptr Word8
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
1) [Word8]
xs
      in Ptr Word8 -> [Word8] -> IO (Int, [Word8])
go Ptr Word8
p0 [Word8]
xs0

packUptoLenChars :: Int -> [Char] -> (ByteString, [Char])
packUptoLenChars :: Int -> String -> (ByteString, String)
packUptoLenChars Int
len String
cs0 =
    forall a. Int -> (Ptr Word8 -> IO (Int, a)) -> (ByteString, a)
unsafeCreateUptoN' Int
len forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p0 ->
      let p_end :: Ptr Word8
p_end = forall a b. Ptr a -> Int -> Ptr b
plusPtr Ptr Word8
p0 Int
len
          go :: Ptr Word8 -> String -> IO (Int, String)
go !Ptr Word8
p []              = forall (m :: * -> *) a. Monad m => a -> m a
return (Ptr Word8
p forall a b. Ptr a -> Ptr b -> Int
`minusPtr` Ptr Word8
p0, [])
          go !Ptr Word8
p String
cs | Ptr Word8
p forall a. Eq a => a -> a -> Bool
== Ptr Word8
p_end = forall (m :: * -> *) a. Monad m => a -> m a
return (Int
len, String
cs)
          go !Ptr Word8
p (Char
c:String
cs)          = forall a. Storable a => Ptr a -> a -> IO ()
poke Ptr Word8
p (Char -> Word8
c2w Char
c) forall (m :: * -> *) a b. Monad m => m a -> m b -> m b
>> Ptr Word8 -> String -> IO (Int, String)
go (Ptr Word8
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
1) String
cs
      in Ptr Word8 -> String -> IO (Int, String)
go Ptr Word8
p0 String
cs0

-- Unpacking bytestrings into lists efficiently is a tradeoff: on the one hand
-- we would like to write a tight loop that just blasts the list into memory, on
-- the other hand we want it to be unpacked lazily so we don't end up with a
-- massive list data structure in memory.
--
-- Our strategy is to combine both: we will unpack lazily in reasonable sized
-- chunks, where each chunk is unpacked strictly.
--
-- unpackBytes and unpackChars do the lazy loop, while unpackAppendBytes and
-- unpackAppendChars do the chunks strictly.

unpackBytes :: ByteString -> [Word8]
unpackBytes :: ByteString -> [Word8]
unpackBytes ByteString
bs = ByteString -> [Word8] -> [Word8]
unpackAppendBytesLazy ByteString
bs []

unpackChars :: ByteString -> [Char]
unpackChars :: ByteString -> String
unpackChars ByteString
bs = ByteString -> ShowS
unpackAppendCharsLazy ByteString
bs []

unpackAppendBytesLazy :: ByteString -> [Word8] -> [Word8]
unpackAppendBytesLazy :: ByteString -> [Word8] -> [Word8]
unpackAppendBytesLazy (BS ForeignPtr Word8
fp Int
len) [Word8]
xs
  | Int
len forall a. Ord a => a -> a -> Bool
<= Int
100 = ByteString -> [Word8] -> [Word8]
unpackAppendBytesStrict (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
len) [Word8]
xs
  | Bool
otherwise  = ByteString -> [Word8] -> [Word8]
unpackAppendBytesStrict (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
100) [Word8]
remainder
  where
    remainder :: [Word8]
remainder  = ByteString -> [Word8] -> [Word8]
unpackAppendBytesLazy (ForeignPtr Word8 -> Int -> ByteString
BS (forall a b. ForeignPtr a -> Int -> ForeignPtr b
plusForeignPtr ForeignPtr Word8
fp Int
100) (Int
lenforall a. Num a => a -> a -> a
-Int
100)) [Word8]
xs

  -- Why 100 bytes you ask? Because on a 64bit machine the list we allocate
  -- takes just shy of 4k which seems like a reasonable amount.
  -- (5 words per list element, 8 bytes per word, 100 elements = 4000 bytes)

unpackAppendCharsLazy :: ByteString -> [Char] -> [Char]
unpackAppendCharsLazy :: ByteString -> ShowS
unpackAppendCharsLazy (BS ForeignPtr Word8
fp Int
len) String
cs
  | Int
len forall a. Ord a => a -> a -> Bool
<= Int
100 = ByteString -> ShowS
unpackAppendCharsStrict (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
len) String
cs
  | Bool
otherwise  = ByteString -> ShowS
unpackAppendCharsStrict (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
100) String
remainder
  where
    remainder :: String
remainder  = ByteString -> ShowS
unpackAppendCharsLazy (ForeignPtr Word8 -> Int -> ByteString
BS (forall a b. ForeignPtr a -> Int -> ForeignPtr b
plusForeignPtr ForeignPtr Word8
fp Int
100) (Int
lenforall a. Num a => a -> a -> a
-Int
100)) String
cs

-- For these unpack functions, since we're unpacking the whole list strictly we
-- build up the result list in an accumulator. This means we have to build up
-- the list starting at the end. So our traversal starts at the end of the
-- buffer and loops down until we hit the sentinal:

unpackAppendBytesStrict :: ByteString -> [Word8] -> [Word8]
unpackAppendBytesStrict :: ByteString -> [Word8] -> [Word8]
unpackAppendBytesStrict (BS ForeignPtr Word8
fp Int
len) [Word8]
xs =
    forall a. IO a -> a
accursedUnutterablePerformIO forall a b. (a -> b) -> a -> b
$ forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
base ->
      forall {b}. Storable b => Ptr b -> Ptr b -> [b] -> IO [b]
loop (Ptr Word8
base forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1)) (Ptr Word8
base forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1forall a. Num a => a -> a -> a
+Int
len)) [Word8]
xs
  where
    loop :: Ptr b -> Ptr b -> [b] -> IO [b]
loop !Ptr b
sentinal !Ptr b
p [b]
acc
      | Ptr b
p forall a. Eq a => a -> a -> Bool
== Ptr b
sentinal = forall (m :: * -> *) a. Monad m => a -> m a
return [b]
acc
      | Bool
otherwise     = do b
x <- forall a. Storable a => Ptr a -> IO a
peek Ptr b
p
                           Ptr b -> Ptr b -> [b] -> IO [b]
loop Ptr b
sentinal (Ptr b
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1)) (b
xforall a. a -> [a] -> [a]
:[b]
acc)

unpackAppendCharsStrict :: ByteString -> [Char] -> [Char]
unpackAppendCharsStrict :: ByteString -> ShowS
unpackAppendCharsStrict (BS ForeignPtr Word8
fp Int
len) String
xs =
    forall a. IO a -> a
accursedUnutterablePerformIO forall a b. (a -> b) -> a -> b
$ forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
base ->
      Ptr Word8 -> Ptr Word8 -> String -> IO String
loop (Ptr Word8
base forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1)) (Ptr Word8
base forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1forall a. Num a => a -> a -> a
+Int
len)) String
xs
  where
    loop :: Ptr Word8 -> Ptr Word8 -> String -> IO String
loop !Ptr Word8
sentinal !Ptr Word8
p String
acc
      | Ptr Word8
p forall a. Eq a => a -> a -> Bool
== Ptr Word8
sentinal = forall (m :: * -> *) a. Monad m => a -> m a
return String
acc
      | Bool
otherwise     = do Word8
x <- forall a. Storable a => Ptr a -> IO a
peek Ptr Word8
p
                           Ptr Word8 -> Ptr Word8 -> String -> IO String
loop Ptr Word8
sentinal (Ptr Word8
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` (-Int
1)) (Word8 -> Char
w2c Word8
xforall a. a -> [a] -> [a]
:String
acc)

------------------------------------------------------------------------

-- | The 0 pointer. Used to indicate the empty Bytestring.
nullForeignPtr :: ForeignPtr Word8
#if __GLASGOW_HASKELL__ >= 811
nullForeignPtr :: ForeignPtr Word8
nullForeignPtr = forall a. Addr# -> ForeignPtrContents -> ForeignPtr a
ForeignPtr Addr#
nullAddr# ForeignPtrContents
FinalPtr
#else
nullForeignPtr = ForeignPtr nullAddr# (error "nullForeignPtr")
#endif

-- ---------------------------------------------------------------------
-- Low level constructors

-- | /O(1)/ Build a ByteString from a ForeignPtr.
--
-- If you do not need the offset parameter then you should be using
-- 'Data.ByteString.Unsafe.unsafePackCStringLen' or
-- 'Data.ByteString.Unsafe.unsafePackCStringFinalizer' instead.
--
fromForeignPtr :: ForeignPtr Word8
               -> Int -- ^ Offset
               -> Int -- ^ Length
               -> ByteString
fromForeignPtr :: ForeignPtr Word8 -> Int -> Int -> ByteString
fromForeignPtr ForeignPtr Word8
fp Int
o = ForeignPtr Word8 -> Int -> ByteString
BS (forall a b. ForeignPtr a -> Int -> ForeignPtr b
plusForeignPtr ForeignPtr Word8
fp Int
o)
{-# INLINE fromForeignPtr #-}

-- | @since 0.11.0.0
fromForeignPtr0 :: ForeignPtr Word8
               -> Int -- ^ Length
               -> ByteString
fromForeignPtr0 :: ForeignPtr Word8 -> Int -> ByteString
fromForeignPtr0 = ForeignPtr Word8 -> Int -> ByteString
BS
{-# INLINE fromForeignPtr0 #-}

-- | /O(1)/ Deconstruct a ForeignPtr from a ByteString
toForeignPtr :: ByteString -> (ForeignPtr Word8, Int, Int) -- ^ (ptr, offset, length)
toForeignPtr :: ByteString -> (ForeignPtr Word8, Int, Int)
toForeignPtr (BS ForeignPtr Word8
ps Int
l) = (ForeignPtr Word8
ps, Int
0, Int
l)
{-# INLINE toForeignPtr #-}

-- | /O(1)/ Deconstruct a ForeignPtr from a ByteString
--
-- @since 0.11.0.0
toForeignPtr0 :: ByteString -> (ForeignPtr Word8, Int) -- ^ (ptr, length)
toForeignPtr0 :: ByteString -> (ForeignPtr Word8, Int)
toForeignPtr0 (BS ForeignPtr Word8
ps Int
l) = (ForeignPtr Word8
ps, Int
l)
{-# INLINE toForeignPtr0 #-}

-- | A way of creating ByteStrings outside the IO monad. The @Int@
-- argument gives the final size of the ByteString.
unsafeCreate :: Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate :: Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
l Ptr Word8 -> IO ()
f = forall a. IO a -> a
unsafeDupablePerformIO (Int -> (Ptr Word8 -> IO ()) -> IO ByteString
create Int
l Ptr Word8 -> IO ()
f)
{-# INLINE unsafeCreate #-}

-- | Like 'unsafeCreate' but instead of giving the final size of the
-- ByteString, it is just an upper bound. The inner action returns
-- the actual size. Unlike 'createAndTrim' the ByteString is not
-- reallocated if the final size is less than the estimated size.
unsafeCreateUptoN :: Int -> (Ptr Word8 -> IO Int) -> ByteString
unsafeCreateUptoN :: Int -> (Ptr Word8 -> IO Int) -> ByteString
unsafeCreateUptoN Int
l Ptr Word8 -> IO Int
f = forall a. IO a -> a
unsafeDupablePerformIO (Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createUptoN Int
l Ptr Word8 -> IO Int
f)
{-# INLINE unsafeCreateUptoN #-}

-- | @since 0.10.12.0
unsafeCreateUptoN' :: Int -> (Ptr Word8 -> IO (Int, a)) -> (ByteString, a)
unsafeCreateUptoN' :: forall a. Int -> (Ptr Word8 -> IO (Int, a)) -> (ByteString, a)
unsafeCreateUptoN' Int
l Ptr Word8 -> IO (Int, a)
f = forall a. IO a -> a
unsafeDupablePerformIO (forall a. Int -> (Ptr Word8 -> IO (Int, a)) -> IO (ByteString, a)
createUptoN' Int
l Ptr Word8 -> IO (Int, a)
f)
{-# INLINE unsafeCreateUptoN' #-}

-- | Create ByteString of size @l@ and use action @f@ to fill its contents.
create :: Int -> (Ptr Word8 -> IO ()) -> IO ByteString
create :: Int -> (Ptr Word8 -> IO ()) -> IO ByteString
create Int
l Ptr Word8 -> IO ()
action = do
    ForeignPtr Word8
fp <- forall a. Int -> IO (ForeignPtr a)
mallocByteString Int
l
    -- Cannot use unsafeWithForeignPtr, because action can diverge
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> Ptr Word8 -> IO ()
action Ptr Word8
p
    forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
l
{-# INLINE create #-}

-- | Given a maximum size @l@ and an action @f@ that fills the 'ByteString'
-- starting at the given 'Ptr' and returns the actual utilized length,
-- @`createUptoN'` l f@ returns the filled 'ByteString'.
createUptoN :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createUptoN :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createUptoN Int
l Ptr Word8 -> IO Int
action = do
    ForeignPtr Word8
fp <- forall a. Int -> IO (ForeignPtr a)
mallocByteString Int
l
    -- Cannot use unsafeWithForeignPtr, because action can diverge
    Int
l' <- forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> Ptr Word8 -> IO Int
action Ptr Word8
p
    forall a. (?callStack::CallStack) => Bool -> a -> a
assert (Int
l' forall a. Ord a => a -> a -> Bool
<= Int
l) forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
l'
{-# INLINE createUptoN #-}

-- | Like 'createUptoN', but also returns an additional value created by the
-- action.
--
-- @since 0.10.12.0
createUptoN' :: Int -> (Ptr Word8 -> IO (Int, a)) -> IO (ByteString, a)
createUptoN' :: forall a. Int -> (Ptr Word8 -> IO (Int, a)) -> IO (ByteString, a)
createUptoN' Int
l Ptr Word8 -> IO (Int, a)
action = do
    ForeignPtr Word8
fp <- forall a. Int -> IO (ForeignPtr a)
mallocByteString Int
l
    -- Cannot use unsafeWithForeignPtr, because action can diverge
    (Int
l', a
res) <- forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> Ptr Word8 -> IO (Int, a)
action Ptr Word8
p
    forall a. (?callStack::CallStack) => Bool -> a -> a
assert (Int
l' forall a. Ord a => a -> a -> Bool
<= Int
l) forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => a -> m a
return (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
l', a
res)
{-# INLINE createUptoN' #-}

-- | Given the maximum size needed and a function to make the contents
-- of a ByteString, createAndTrim makes the 'ByteString'. The generating
-- function is required to return the actual final size (<= the maximum
-- size), and the resulting byte array is reallocated to this size.
--
-- createAndTrim is the main mechanism for creating custom, efficient
-- ByteString functions, using Haskell or C functions to fill the space.
--
createAndTrim :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createAndTrim :: Int -> (Ptr Word8 -> IO Int) -> IO ByteString
createAndTrim Int
l Ptr Word8 -> IO Int
action = do
    ForeignPtr Word8
fp <- forall a. Int -> IO (ForeignPtr a)
mallocByteString Int
l
    -- Cannot use unsafeWithForeignPtr, because action can diverge
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
        Int
l' <- Ptr Word8 -> IO Int
action Ptr Word8
p
        if forall a. (?callStack::CallStack) => Bool -> a -> a
assert (Int
l' forall a. Ord a => a -> a -> Bool
<= Int
l) forall a b. (a -> b) -> a -> b
$ Int
l' forall a. Ord a => a -> a -> Bool
>= Int
l
            then forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
l
            else Int -> (Ptr Word8 -> IO ()) -> IO ByteString
create Int
l' forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p' -> Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
p' Ptr Word8
p Int
l'
{-# INLINE createAndTrim #-}

createAndTrim' :: Int -> (Ptr Word8 -> IO (Int, Int, a)) -> IO (ByteString, a)
createAndTrim' :: forall a.
Int -> (Ptr Word8 -> IO (Int, Int, a)) -> IO (ByteString, a)
createAndTrim' Int
l Ptr Word8 -> IO (Int, Int, a)
action = do
    ForeignPtr Word8
fp <- forall a. Int -> IO (ForeignPtr a)
mallocByteString Int
l
    -- Cannot use unsafeWithForeignPtr, because action can diverge
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
withForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
        (Int
off, Int
l', a
res) <- Ptr Word8 -> IO (Int, Int, a)
action Ptr Word8
p
        if forall a. (?callStack::CallStack) => Bool -> a -> a
assert (Int
l' forall a. Ord a => a -> a -> Bool
<= Int
l) forall a b. (a -> b) -> a -> b
$ Int
l' forall a. Ord a => a -> a -> Bool
>= Int
l
            then forall (m :: * -> *) a. Monad m => a -> m a
return (ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
l, a
res)
            else do ByteString
ps <- Int -> (Ptr Word8 -> IO ()) -> IO ByteString
create Int
l' forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p' ->
                            Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
p' (Ptr Word8
p forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
off) Int
l'
                    forall (m :: * -> *) a. Monad m => a -> m a
return (ByteString
ps, a
res)
{-# INLINE createAndTrim' #-}

-- | Wrapper of 'Foreign.ForeignPtr.mallocForeignPtrBytes' with faster implementation for GHC
--
mallocByteString :: Int -> IO (ForeignPtr a)
mallocByteString :: forall a. Int -> IO (ForeignPtr a)
mallocByteString = forall a. Int -> IO (ForeignPtr a)
mallocPlainForeignPtrBytes
{-# INLINE mallocByteString #-}

------------------------------------------------------------------------
-- Implementations for Eq, Ord and Monoid instances

eq :: ByteString -> ByteString -> Bool
eq :: ByteString -> ByteString -> Bool
eq a :: ByteString
a@(BS ForeignPtr Word8
fp Int
len) b :: ByteString
b@(BS ForeignPtr Word8
fp' Int
len')
  | Int
len forall a. Eq a => a -> a -> Bool
/= Int
len' = Bool
False    -- short cut on length
  | ForeignPtr Word8
fp forall a. Eq a => a -> a -> Bool
== ForeignPtr Word8
fp'   = Bool
True     -- short cut for the same string
  | Bool
otherwise   = ByteString -> ByteString -> Ordering
compareBytes ByteString
a ByteString
b forall a. Eq a => a -> a -> Bool
== Ordering
EQ
{-# INLINE eq #-}
-- ^ still needed

compareBytes :: ByteString -> ByteString -> Ordering
compareBytes :: ByteString -> ByteString -> Ordering
compareBytes (BS ForeignPtr Word8
_   Int
0)    (BS ForeignPtr Word8
_   Int
0)    = Ordering
EQ  -- short cut for empty strings
compareBytes (BS ForeignPtr Word8
fp1 Int
len1) (BS ForeignPtr Word8
fp2 Int
len2) =
    forall a. IO a -> a
accursedUnutterablePerformIO forall a b. (a -> b) -> a -> b
$
      forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp1 forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p1 ->
      forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp2 forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p2 -> do
        CInt
i <- Ptr Word8 -> Ptr Word8 -> Int -> IO CInt
memcmp Ptr Word8
p1 Ptr Word8
p2 (forall a. Ord a => a -> a -> a
min Int
len1 Int
len2)
        forall (m :: * -> *) a. Monad m => a -> m a
return forall a b. (a -> b) -> a -> b
$! case CInt
i forall a. Ord a => a -> a -> Ordering
`compare` CInt
0 of
                    Ordering
EQ  -> Int
len1 forall a. Ord a => a -> a -> Ordering
`compare` Int
len2
                    Ordering
x   -> Ordering
x


-- | /O(1)/ The empty 'ByteString'
empty :: ByteString
-- This enables bypassing #457 by not using (polymorphic) mempty in
-- any definitions used by the (Monoid ByteString) instance
empty :: ByteString
empty = ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
nullForeignPtr Int
0

append :: ByteString -> ByteString -> ByteString
append :: ByteString -> ByteString -> ByteString
append (BS ForeignPtr Word8
_   Int
0)    ByteString
b                  = ByteString
b
append ByteString
a             (BS ForeignPtr Word8
_   Int
0)    = ByteString
a
append (BS ForeignPtr Word8
fp1 Int
len1) (BS ForeignPtr Word8
fp2 Int
len2) =
    Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate (Int
len1forall a. Num a => a -> a -> a
+Int
len2) forall a b. (a -> b) -> a -> b
$ \Ptr Word8
destptr1 -> do
      let destptr2 :: Ptr Word8
destptr2 = Ptr Word8
destptr1 forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
len1
      forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp1 forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p1 -> Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
destptr1 Ptr Word8
p1 Int
len1
      forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp2 forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p2 -> Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
destptr2 Ptr Word8
p2 Int
len2

concat :: [ByteString] -> ByteString
concat :: [ByteString] -> ByteString
concat = \[ByteString]
bss0 -> [ByteString] -> [ByteString] -> ByteString
goLen0 [ByteString]
bss0 [ByteString]
bss0
    -- The idea here is we first do a pass over the input list to determine:
    --
    --  1. is a copy necessary? e.g. @concat []@, @concat [mempty, "hello"]@,
    --     and @concat ["hello", mempty, mempty]@ can all be handled without
    --     copying.
    --  2. if a copy is necessary, how large is the result going to be?
    --
    -- If a copy is necessary then we create a buffer of the appropriate size
    -- and do another pass over the input list, copying the chunks into the
    -- buffer. Also, since foreign calls aren't entirely free we skip over
    -- empty chunks while copying.
    --
    -- We pass the original [ByteString] (bss0) through as an argument through
    -- goLen0, goLen1, and goLen since we will need it again in goCopy. Passing
    -- it as an explicit argument avoids capturing it in these functions'
    -- closures which would result in unnecessary closure allocation.
  where
    -- It's still possible that the result is empty
    goLen0 :: [ByteString] -> [ByteString] -> ByteString
goLen0 [ByteString]
_    []                     = ByteString
empty
    goLen0 [ByteString]
bss0 (BS ForeignPtr Word8
_ Int
0     :[ByteString]
bss)    = [ByteString] -> [ByteString] -> ByteString
goLen0 [ByteString]
bss0 [ByteString]
bss
    goLen0 [ByteString]
bss0 (ByteString
bs           :[ByteString]
bss)    = [ByteString] -> ByteString -> [ByteString] -> ByteString
goLen1 [ByteString]
bss0 ByteString
bs [ByteString]
bss

    -- It's still possible that the result is a single chunk
    goLen1 :: [ByteString] -> ByteString -> [ByteString] -> ByteString
goLen1 [ByteString]
_    ByteString
bs []                  = ByteString
bs
    goLen1 [ByteString]
bss0 ByteString
bs (BS ForeignPtr Word8
_ Int
0  :[ByteString]
bss)    = [ByteString] -> ByteString -> [ByteString] -> ByteString
goLen1 [ByteString]
bss0 ByteString
bs [ByteString]
bss
    goLen1 [ByteString]
bss0 ByteString
bs (BS ForeignPtr Word8
_ Int
len:[ByteString]
bss)    = [ByteString] -> Int -> [ByteString] -> ByteString
goLen [ByteString]
bss0 (String -> Int -> Int -> Int
checkedAdd String
"concat" Int
len' Int
len) [ByteString]
bss
      where BS ForeignPtr Word8
_ Int
len' = ByteString
bs

    -- General case, just find the total length we'll need
    goLen :: [ByteString] -> Int -> [ByteString] -> ByteString
goLen [ByteString]
bss0 !Int
total (BS ForeignPtr Word8
_ Int
len:[ByteString]
bss) = [ByteString] -> Int -> [ByteString] -> ByteString
goLen [ByteString]
bss0 Int
total' [ByteString]
bss
      where total' :: Int
total' = String -> Int -> Int -> Int
checkedAdd String
"concat" Int
total Int
len
    goLen [ByteString]
bss0 Int
total [] =
      Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
total forall a b. (a -> b) -> a -> b
$ \Ptr Word8
ptr -> [ByteString] -> Ptr Word8 -> IO ()
goCopy [ByteString]
bss0 Ptr Word8
ptr

    -- Copy the data
    goCopy :: [ByteString] -> Ptr Word8 -> IO ()
goCopy []                  !Ptr Word8
_   = forall (m :: * -> *) a. Monad m => a -> m a
return ()
    goCopy (BS ForeignPtr Word8
_  Int
0  :[ByteString]
bss) !Ptr Word8
ptr = [ByteString] -> Ptr Word8 -> IO ()
goCopy [ByteString]
bss Ptr Word8
ptr
    goCopy (BS ForeignPtr Word8
fp Int
len:[ByteString]
bss) !Ptr Word8
ptr = do
      forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
ptr Ptr Word8
p Int
len
      [ByteString] -> Ptr Word8 -> IO ()
goCopy [ByteString]
bss (Ptr Word8
ptr forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
len)
{-# NOINLINE concat #-}

{-# RULES
"ByteString concat [] -> empty"
   concat [] = empty
"ByteString concat [bs] -> bs" forall x.
   concat [x] = x
 #-}

-- | /O(log n)/ Repeats the given ByteString n times.
times :: Integral a => a -> ByteString -> ByteString
times :: forall b. Integral b => b -> ByteString -> ByteString
times a
n (BS ForeignPtr Word8
fp Int
len)
  | a
n forall a. Ord a => a -> a -> Bool
< a
0 = forall a. (?callStack::CallStack) => String -> a
error String
"stimes: non-negative multiplier expected"
  | a
n forall a. Eq a => a -> a -> Bool
== a
0 = ByteString
empty
  | a
n forall a. Eq a => a -> a -> Bool
== a
1 = ForeignPtr Word8 -> Int -> ByteString
BS ForeignPtr Word8
fp Int
len
  | Int
len forall a. Eq a => a -> a -> Bool
== Int
0 = ByteString
empty
  | Int
len forall a. Eq a => a -> a -> Bool
== Int
1 = Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
size forall a b. (a -> b) -> a -> b
$ \Ptr Word8
destptr ->
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
      Word8
byte <- forall a. Storable a => Ptr a -> IO a
peek Ptr Word8
p
      forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memset Ptr Word8
destptr Word8
byte (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
size)
  | Bool
otherwise = Int -> (Ptr Word8 -> IO ()) -> ByteString
unsafeCreate Int
size forall a b. (a -> b) -> a -> b
$ \Ptr Word8
destptr ->
    forall a b. ForeignPtr a -> (Ptr a -> IO b) -> IO b
unsafeWithForeignPtr ForeignPtr Word8
fp forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
      Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
destptr Ptr Word8
p Int
len
      Ptr Word8 -> Int -> IO ()
fillFrom Ptr Word8
destptr Int
len
  where
    size :: Int
size = Int
len forall a. Num a => a -> a -> a
* forall a b. (Integral a, Num b) => a -> b
fromIntegral a
n

    fillFrom :: Ptr Word8 -> Int -> IO ()
    fillFrom :: Ptr Word8 -> Int -> IO ()
fillFrom Ptr Word8
destptr Int
copied
      | Int
2 forall a. Num a => a -> a -> a
* Int
copied forall a. Ord a => a -> a -> Bool
< Int
size = do
        Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy (Ptr Word8
destptr forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
copied) Ptr Word8
destptr Int
copied
        Ptr Word8 -> Int -> IO ()
fillFrom Ptr Word8
destptr (Int
copied forall a. Num a => a -> a -> a
* Int
2)
      | Bool
otherwise = Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy (Ptr Word8
destptr forall a b. Ptr a -> Int -> Ptr b
`plusPtr` Int
copied) Ptr Word8
destptr (Int
size forall a. Num a => a -> a -> a
- Int
copied)

-- | Add two non-negative numbers. Errors out on overflow.
checkedAdd :: String -> Int -> Int -> Int
checkedAdd :: String -> Int -> Int -> Int
checkedAdd String
fun Int
x Int
y
  | Int
r forall a. Ord a => a -> a -> Bool
>= Int
0    = Int
r
  | Bool
otherwise = forall a. String -> a
overflowError String
fun
  where r :: Int
r = Int
x forall a. Num a => a -> a -> a
+ Int
y
{-# INLINE checkedAdd #-}

------------------------------------------------------------------------

-- | Conversion between 'Word8' and 'Char'. Should compile to a no-op.
w2c :: Word8 -> Char
w2c :: Word8 -> Char
w2c = Int -> Char
unsafeChr forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a b. (Integral a, Num b) => a -> b
fromIntegral
{-# INLINE w2c #-}

-- | Unsafe conversion between 'Char' and 'Word8'. This is a no-op and
-- silently truncates to 8 bits Chars > '\255'. It is provided as
-- convenience for ByteString construction.
c2w :: Char -> Word8
c2w :: Char -> Word8
c2w = forall a b. (Integral a, Num b) => a -> b
fromIntegral forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Int
ord
{-# INLINE c2w #-}

-- | Selects words corresponding to white-space characters in the Latin-1 range
isSpaceWord8 :: Word8 -> Bool
isSpaceWord8 :: Word8 -> Bool
isSpaceWord8 Word8
w8 =
    -- Avoid the cost of narrowing arithmetic results to Word8,
    -- the conversion from Word8 to Word is free.
    let w :: Word
        !w :: Word
w = forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
w8
     in Word
w forall a. Bits a => a -> a -> a
.&. Word
0x50 forall a. Eq a => a -> a -> Bool
== Word
0    -- Quick non-whitespace filter
        Bool -> Bool -> Bool
&& Word
w forall a. Num a => a -> a -> a
- Word
0x21 forall a. Ord a => a -> a -> Bool
> Word
0x7e -- Second non-whitespace filter
        Bool -> Bool -> Bool
&& ( Word
w forall a. Eq a => a -> a -> Bool
== Word
0x20     -- SP
          Bool -> Bool -> Bool
|| Word
w forall a. Eq a => a -> a -> Bool
== Word
0xa0     -- NBSP
          Bool -> Bool -> Bool
|| Word
w forall a. Num a => a -> a -> a
- Word
0x09 forall a. Ord a => a -> a -> Bool
< Word
5) -- HT, NL, VT, FF, CR
{-# INLINE isSpaceWord8 #-}

-- | Selects white-space characters in the Latin-1 range
isSpaceChar8 :: Char -> Bool
isSpaceChar8 :: Char -> Bool
isSpaceChar8 = Word8 -> Bool
isSpaceWord8 forall b c a. (b -> c) -> (a -> b) -> a -> c
. Char -> Word8
c2w
{-# INLINE isSpaceChar8 #-}

overflowError :: String -> a
overflowError :: forall a. String -> a
overflowError String
fun = forall a. (?callStack::CallStack) => String -> a
error forall a b. (a -> b) -> a -> b
$ String
"Data.ByteString." forall a. [a] -> [a] -> [a]
++ String
fun forall a. [a] -> [a] -> [a]
++ String
": size overflow"

------------------------------------------------------------------------

-- | This \"function\" has a superficial similarity to 'System.IO.Unsafe.unsafePerformIO' but
-- it is in fact a malevolent agent of chaos. It unpicks the seams of reality
-- (and the 'IO' monad) so that the normal rules no longer apply. It lulls you
-- into thinking it is reasonable, but when you are not looking it stabs you
-- in the back and aliases all of your mutable buffers. The carcass of many a
-- seasoned Haskell programmer lie strewn at its feet.
--
-- Witness the trail of destruction:
--
-- * <https://github.com/haskell/bytestring/commit/71c4b438c675aa360c79d79acc9a491e7bbc26e7>
--
-- * <https://github.com/haskell/bytestring/commit/210c656390ae617d9ee3b8bcff5c88dd17cef8da>
--
-- * <https://ghc.haskell.org/trac/ghc/ticket/3486>
--
-- * <https://ghc.haskell.org/trac/ghc/ticket/3487>
--
-- * <https://ghc.haskell.org/trac/ghc/ticket/7270>
--
-- Do not talk about \"safe\"! You do not know what is safe!
--
-- Yield not to its blasphemous call! Flee traveller! Flee or you will be
-- corrupted and devoured!
--
{-# INLINE accursedUnutterablePerformIO #-}
accursedUnutterablePerformIO :: IO a -> a
accursedUnutterablePerformIO :: forall a. IO a -> a
accursedUnutterablePerformIO (IO State# RealWorld -> (# State# RealWorld, a #)
m) = case State# RealWorld -> (# State# RealWorld, a #)
m State# RealWorld
realWorld# of (# State# RealWorld
_, a
r #) -> a
r

-- ---------------------------------------------------------------------
--
-- Standard C functions
--

foreign import ccall unsafe "string.h strlen" c_strlen
    :: CString -> IO CSize

foreign import ccall unsafe "static stdlib.h &free" c_free_finalizer
    :: FunPtr (Ptr Word8 -> IO ())

foreign import ccall unsafe "string.h memchr" c_memchr
    :: Ptr Word8 -> CInt -> CSize -> IO (Ptr Word8)

memchr :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memchr :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memchr Ptr Word8
p Word8
w = Ptr Word8 -> CInt -> CSize -> IO (Ptr Word8)
c_memchr Ptr Word8
p (forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
w)

foreign import ccall unsafe "string.h memcmp" c_memcmp
    :: Ptr Word8 -> Ptr Word8 -> CSize -> IO CInt

memcmp :: Ptr Word8 -> Ptr Word8 -> Int -> IO CInt
memcmp :: Ptr Word8 -> Ptr Word8 -> Int -> IO CInt
memcmp Ptr Word8
p Ptr Word8
q Int
s = Ptr Word8 -> Ptr Word8 -> CSize -> IO CInt
c_memcmp Ptr Word8
p Ptr Word8
q (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
s)

foreign import ccall unsafe "string.h memcpy" c_memcpy
    :: Ptr Word8 -> Ptr Word8 -> CSize -> IO (Ptr Word8)

memcpy :: Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy :: Ptr Word8 -> Ptr Word8 -> Int -> IO ()
memcpy Ptr Word8
p Ptr Word8
q Int
s = forall (f :: * -> *) a. Functor f => f a -> f ()
void forall a b. (a -> b) -> a -> b
$ Ptr Word8 -> Ptr Word8 -> CSize -> IO (Ptr Word8)
c_memcpy Ptr Word8
p Ptr Word8
q (forall a b. (Integral a, Num b) => a -> b
fromIntegral Int
s)

{-
foreign import ccall unsafe "string.h memmove" c_memmove
    :: Ptr Word8 -> Ptr Word8 -> CSize -> IO (Ptr Word8)

memmove :: Ptr Word8 -> Ptr Word8 -> CSize -> IO ()
memmove p q s = do c_memmove p q s
                   return ()
-}

foreign import ccall unsafe "string.h memset" c_memset
    :: Ptr Word8 -> CInt -> CSize -> IO (Ptr Word8)

memset :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memset :: Ptr Word8 -> Word8 -> CSize -> IO (Ptr Word8)
memset Ptr Word8
p Word8
w = Ptr Word8 -> CInt -> CSize -> IO (Ptr Word8)
c_memset Ptr Word8
p (forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
w)

-- ---------------------------------------------------------------------
--
-- Uses our C code
--

foreign import ccall unsafe "static fpstring.h fps_reverse" c_reverse
    :: Ptr Word8 -> Ptr Word8 -> CSize -> IO ()

foreign import ccall unsafe "static fpstring.h fps_intersperse" c_intersperse
    :: Ptr Word8 -> Ptr Word8 -> CSize -> Word8 -> IO ()

foreign import ccall unsafe "static fpstring.h fps_maximum" c_maximum
    :: Ptr Word8 -> CSize -> IO Word8

foreign import ccall unsafe "static fpstring.h fps_minimum" c_minimum
    :: Ptr Word8 -> CSize -> IO Word8

foreign import ccall unsafe "static fpstring.h fps_count" c_count
    :: Ptr Word8 -> CSize -> Word8 -> IO CSize

foreign import ccall unsafe "static fpstring.h fps_sort" c_sort
    :: Ptr Word8 -> CSize -> IO ()