{-# LANGUAGE BangPatterns, CPP, MagicHash, Rank2Types,
    RecordWildCards, UnboxedTuples, UnliftedFFITypes #-}
{-# OPTIONS_GHC -fno-warn-unused-matches #-}
-- |
-- Module      : Data.Text.Array
-- Copyright   : (c) 2009, 2010, 2011 Bryan O'Sullivan
--
-- License     : BSD-style
-- Maintainer  : bos@serpentine.com
-- Portability : portable
--
-- Packed, unboxed, heap-resident arrays.  Suitable for performance
-- critical use, both in terms of large data quantities and high
-- speed.
--
-- This module is intended to be imported @qualified@, to avoid name
-- clashes with "Prelude" functions, e.g.
--
-- > import qualified Data.Text.Array as A
--
-- The names in this module resemble those in the 'Data.Array' family
-- of modules, but are shorter due to the assumption of qualified
-- naming.
module Data.Text.Array
    (
    -- * Types
      Array(..)
    , MArray(..)
    -- * Functions
    , copyM
    , copyI
    , empty
    , equal
    , run
    , run2
    , toList
    , unsafeFreeze
    , unsafeIndex
    , new
    , unsafeWrite
    ) where

#if defined(ASSERTS)
import Control.Exception (assert)
import GHC.Base (sizeofByteArray#, sizeofMutableByteArray#)
import GHC.Stack (HasCallStack)
#endif
import Control.Monad.ST.Unsafe (unsafeIOToST)
import Data.Bits ((.&.), xor)
import Data.Text.Internal.Unsafe (inlinePerformIO)
import Data.Text.Internal.Unsafe.Shift (shiftL, shiftR)
import Foreign.C.Types (CInt(CInt), CSize(CSize))
import GHC.Base (ByteArray#, MutableByteArray#, Int(..),
                 indexWord16Array#, newByteArray#,
                 unsafeFreezeByteArray#, writeWord16Array#)
import GHC.ST (ST(..), runST)
import GHC.Word (Word16(..))
import Prelude hiding (length, read)

-- | Immutable array type.
--
-- The 'Array' constructor is exposed since @text-1.1.1.3@
data Array = Array { Array -> ByteArray#
aBA :: ByteArray# }

-- | Mutable array type, for use in the ST monad.
--
-- The 'MArray' constructor is exposed since @text-1.1.1.3@
data MArray s = MArray { forall s. MArray s -> MutableByteArray# s
maBA :: MutableByteArray# s }

-- | Create an uninitialized mutable array.
new :: forall s. Int -> ST s (MArray s)
new :: forall s. Int -> ST s (MArray s)
new Int
n
  | Int
n Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
0 Bool -> Bool -> Bool
|| Int
n Int -> Int -> Int
forall a. Bits a => a -> a -> a
.&. Int
highBit Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
/= Int
0 = ST s (MArray s)
forall a. a
array_size_error
  | Bool
otherwise = STRep s (MArray s) -> ST s (MArray s)
forall s a. STRep s a -> ST s a
ST (STRep s (MArray s) -> ST s (MArray s))
-> STRep s (MArray s) -> ST s (MArray s)
forall a b. (a -> b) -> a -> b
$ \State# s
s1# ->
       case Int# -> State# s -> (# State# s, MutableByteArray# s #)
forall d. Int# -> State# d -> (# State# d, MutableByteArray# d #)
newByteArray# Int#
len# State# s
s1# of
         (# State# s
s2#, MutableByteArray# s
marr# #) -> (# State# s
s2#, MutableByteArray# s -> MArray s
forall s. MutableByteArray# s -> MArray s
MArray MutableByteArray# s
marr# #)
  where !(I# Int#
len#) = Int -> Int
bytesInArray Int
n
        highBit :: Int
highBit    = Int
forall a. Bounded a => a
maxBound Int -> Int -> Int
forall a. Bits a => a -> a -> a
`xor` (Int
forall a. Bounded a => a
maxBound Int -> Int -> Int
forall a. UnsafeShift a => a -> Int -> a
`shiftR` Int
1)
{-# INLINE new #-}

array_size_error :: a
array_size_error :: forall a. a
array_size_error = [Char] -> a
forall a. HasCallStack => [Char] -> a
error [Char]
"Data.Text.Array.new: size overflow"

-- | Freeze a mutable array. Do not mutate the 'MArray' afterwards!
unsafeFreeze :: MArray s -> ST s Array
unsafeFreeze :: forall s. MArray s -> ST s Array
unsafeFreeze MArray{MutableByteArray# s
maBA :: MutableByteArray# s
maBA :: forall s. MArray s -> MutableByteArray# s
..} = STRep s Array -> ST s Array
forall s a. STRep s a -> ST s a
ST (STRep s Array -> ST s Array) -> STRep s Array -> ST s Array
forall a b. (a -> b) -> a -> b
$ \State# s
s1# ->
    case MutableByteArray# s -> State# s -> (# State# s, ByteArray# #)
forall d.
MutableByteArray# d -> State# d -> (# State# d, ByteArray# #)
unsafeFreezeByteArray# MutableByteArray# s
maBA State# s
s1# of
        (# State# s
s2#, ByteArray#
ba# #) -> (# State# s
s2#, ByteArray# -> Array
Array ByteArray#
ba# #)
{-# INLINE unsafeFreeze #-}

-- | Indicate how many bytes would be used for an array of the given
-- size.
bytesInArray :: Int -> Int
bytesInArray :: Int -> Int
bytesInArray Int
n = Int
n Int -> Int -> Int
forall a. UnsafeShift a => a -> Int -> a
`shiftL` Int
1
{-# INLINE bytesInArray #-}

-- | Unchecked read of an immutable array.  May return garbage or
-- crash on an out-of-bounds access.
unsafeIndex ::
#if defined(ASSERTS)
  HasCallStack =>
#endif
  Array -> Int -> Word16
unsafeIndex :: Array -> Int -> Word16
unsafeIndex a :: Array
a@Array{ByteArray#
aBA :: ByteArray#
aBA :: Array -> ByteArray#
..} i :: Int
i@(I# Int#
i#) =
#if defined(ASSERTS)
  let word16len = I# (sizeofByteArray# aBA) `quot` 2 in
  if i < 0 || i >= word16len
  then error ("Data.Text.Array.unsafeIndex: bounds error, offset " ++ show i ++ ", length " ++ show word16len)
  else
#endif
  case ByteArray# -> Int# -> Word16#
indexWord16Array# ByteArray#
aBA Int#
i# of Word16#
r# -> (Word16# -> Word16
W16# Word16#
r#)
{-# INLINE unsafeIndex #-}

-- | Unchecked write of a mutable array.  May return garbage or crash
-- on an out-of-bounds access.
unsafeWrite ::
#if defined(ASSERTS)
  HasCallStack =>
#endif
  MArray s -> Int -> Word16 -> ST s ()
unsafeWrite :: forall s. MArray s -> Int -> Word16 -> ST s ()
unsafeWrite ma :: MArray s
ma@MArray{MutableByteArray# s
maBA :: MutableByteArray# s
maBA :: forall s. MArray s -> MutableByteArray# s
..} i :: Int
i@(I# Int#
i#) (W16# Word16#
e#) = STRep s () -> ST s ()
forall s a. STRep s a -> ST s a
ST (STRep s () -> ST s ()) -> STRep s () -> ST s ()
forall a b. (a -> b) -> a -> b
$ \State# s
s1# ->
#if defined(ASSERTS)
  let word16len = I# (sizeofMutableByteArray# maBA) `quot` 2 in
  if i < 0 || i >= word16len then error ("Data.Text.Array.unsafeWrite: bounds error, offset " ++ show i ++ ", length " ++ show word16len) else
#endif
  case MutableByteArray# s -> Int# -> Word16# -> State# s -> State# s
forall d.
MutableByteArray# d -> Int# -> Word16# -> State# d -> State# d
writeWord16Array# MutableByteArray# s
maBA Int#
i# Word16#
e# State# s
s1# of
    State# s
s2# -> (# State# s
s2#, () #)
{-# INLINE unsafeWrite #-}

-- | Convert an immutable array to a list.
toList :: Array -> Int -> Int -> [Word16]
toList :: Array -> Int -> Int -> [Word16]
toList Array
ary Int
off Int
len = Int -> [Word16]
loop Int
0
    where loop :: Int -> [Word16]
loop Int
i | Int
i Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
< Int
len   = Array -> Int -> Word16
unsafeIndex Array
ary (Int
offInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
i) Word16 -> [Word16] -> [Word16]
forall a. a -> [a] -> [a]
: Int -> [Word16]
loop (Int
iInt -> Int -> Int
forall a. Num a => a -> a -> a
+Int
1)
                 | Bool
otherwise = []

-- | An empty immutable array.
empty :: Array
empty :: Array
empty = (forall s. ST s Array) -> Array
forall a. (forall s. ST s a) -> a
runST (Int -> ST s (MArray s)
forall s. Int -> ST s (MArray s)
new Int
0 ST s (MArray s) -> (MArray s -> ST s Array) -> ST s Array
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= MArray s -> ST s Array
forall s. MArray s -> ST s Array
unsafeFreeze)

-- | Run an action in the ST monad and return an immutable array of
-- its result.
run :: (forall s. ST s (MArray s)) -> Array
run :: (forall s. ST s (MArray s)) -> Array
run forall s. ST s (MArray s)
k = (forall s. ST s Array) -> Array
forall a. (forall s. ST s a) -> a
runST (ST s (MArray s)
forall s. ST s (MArray s)
k ST s (MArray s) -> (MArray s -> ST s Array) -> ST s Array
forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b
>>= MArray s -> ST s Array
forall s. MArray s -> ST s Array
unsafeFreeze)

-- | Run an action in the ST monad and return an immutable array of
-- its result paired with whatever else the action returns.
run2 :: (forall s. ST s (MArray s, a)) -> (Array, a)
run2 :: forall a. (forall s. ST s (MArray s, a)) -> (Array, a)
run2 forall s. ST s (MArray s, a)
k = (forall s. ST s (Array, a)) -> (Array, a)
forall a. (forall s. ST s a) -> a
runST (do
                 (MArray s
marr,a
b) <- ST s (MArray s, a)
forall s. ST s (MArray s, a)
k
                 Array
arr <- MArray s -> ST s Array
forall s. MArray s -> ST s Array
unsafeFreeze MArray s
marr
                 (Array, a) -> ST s (Array, a)
forall (m :: * -> *) a. Monad m => a -> m a
return (Array
arr,a
b))
{-# INLINE run2 #-}

-- | Copy some elements of a mutable array.
copyM :: MArray s               -- ^ Destination
      -> Int                    -- ^ Destination offset
      -> MArray s               -- ^ Source
      -> Int                    -- ^ Source offset
      -> Int                    -- ^ Count
      -> ST s ()
copyM :: forall s. MArray s -> Int -> MArray s -> Int -> Int -> ST s ()
copyM MArray s
dest Int
didx MArray s
src Int
sidx Int
count
    | Int
count Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
<= Int
0 = () -> ST s ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
    | Bool
otherwise =
#if defined(ASSERTS)
    assert (sidx + count <= I# (sizeofMutableByteArray# (maBA src))  `quot` 2) .
    assert (didx + count <= I# (sizeofMutableByteArray# (maBA dest)) `quot` 2) .
#endif
    IO () -> ST s ()
forall a s. IO a -> ST s a
unsafeIOToST (IO () -> ST s ()) -> IO () -> ST s ()
forall a b. (a -> b) -> a -> b
$ MutableByteArray# s
-> CSize -> MutableByteArray# s -> CSize -> CSize -> IO ()
forall s.
MutableByteArray# s
-> CSize -> MutableByteArray# s -> CSize -> CSize -> IO ()
memcpyM (MArray s -> MutableByteArray# s
forall s. MArray s -> MutableByteArray# s
maBA MArray s
dest) (Int -> CSize
intToCSize Int
didx)
                           (MArray s -> MutableByteArray# s
forall s. MArray s -> MutableByteArray# s
maBA MArray s
src) (Int -> CSize
intToCSize Int
sidx)
                           (Int -> CSize
intToCSize Int
count)
{-# INLINE copyM #-}

-- | Copy some elements of an immutable array.
copyI :: MArray s               -- ^ Destination
      -> Int                    -- ^ Destination offset
      -> Array                  -- ^ Source
      -> Int                    -- ^ Source offset
      -> Int                    -- ^ First offset in destination /not/ to
                                -- copy (i.e. /not/ length)
      -> ST s ()
copyI :: forall s. MArray s -> Int -> Array -> Int -> Int -> ST s ()
copyI MArray s
dest Int
i0 Array
src Int
j0 Int
top
    | Int
i0 Int -> Int -> Bool
forall a. Ord a => a -> a -> Bool
>= Int
top = () -> ST s ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()
    | Bool
otherwise = IO () -> ST s ()
forall a s. IO a -> ST s a
unsafeIOToST (IO () -> ST s ()) -> IO () -> ST s ()
forall a b. (a -> b) -> a -> b
$
                  MutableByteArray# s
-> CSize -> ByteArray# -> CSize -> CSize -> IO ()
forall s.
MutableByteArray# s
-> CSize -> ByteArray# -> CSize -> CSize -> IO ()
memcpyI (MArray s -> MutableByteArray# s
forall s. MArray s -> MutableByteArray# s
maBA MArray s
dest) (Int -> CSize
intToCSize Int
i0)
                          (Array -> ByteArray#
aBA Array
src) (Int -> CSize
intToCSize Int
j0)
                          (Int -> CSize
intToCSize (Int
topInt -> Int -> Int
forall a. Num a => a -> a -> a
-Int
i0))
{-# INLINE copyI #-}

-- | Compare portions of two arrays for equality.  No bounds checking
-- is performed.
equal :: Array                  -- ^ First
      -> Int                    -- ^ Offset into first
      -> Array                  -- ^ Second
      -> Int                    -- ^ Offset into second
      -> Int                    -- ^ Count
      -> Bool
equal :: Array -> Int -> Array -> Int -> Int -> Bool
equal Array
arrA Int
offA Array
arrB Int
offB Int
count = IO Bool -> Bool
forall a. IO a -> a
inlinePerformIO (IO Bool -> Bool) -> IO Bool -> Bool
forall a b. (a -> b) -> a -> b
$ do
  CInt
i <- ByteArray# -> CSize -> ByteArray# -> CSize -> CSize -> IO CInt
memcmp (Array -> ByteArray#
aBA Array
arrA) (Int -> CSize
intToCSize Int
offA)
                     (Array -> ByteArray#
aBA Array
arrB) (Int -> CSize
intToCSize Int
offB) (Int -> CSize
intToCSize Int
count)
  Bool -> IO Bool
forall (m :: * -> *) a. Monad m => a -> m a
return (Bool -> IO Bool) -> Bool -> IO Bool
forall a b. (a -> b) -> a -> b
$! CInt
i CInt -> CInt -> Bool
forall a. Eq a => a -> a -> Bool
== CInt
0
{-# INLINE equal #-}

intToCSize :: Int -> CSize
intToCSize :: Int -> CSize
intToCSize = Int -> CSize
forall a b. (Integral a, Num b) => a -> b
fromIntegral

foreign import ccall unsafe "_hs_text_memcpy" memcpyI
    :: MutableByteArray# s -> CSize -> ByteArray# -> CSize -> CSize -> IO ()

foreign import ccall unsafe "_hs_text_memcmp" memcmp
    :: ByteArray# -> CSize -> ByteArray# -> CSize -> CSize -> IO CInt

foreign import ccall unsafe "_hs_text_memcpy" memcpyM
    :: MutableByteArray# s -> CSize -> MutableByteArray# s -> CSize -> CSize
    -> IO ()