Switch builder implementation to use chunks (#10)
* switch builder implementation to use chunks * micro-optimize the conditional for builders of length one * use fromBoundedOne for ascii chars
This commit is contained in:
Andrew Martin
GitHub
parent
3ad5261ff4
commit
8baf4cc369
6 changed files with 347 additions and 249 deletions
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@ -1,4 +1,5 @@
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{-# language BangPatterns #-}
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{-# language DataKinds #-}
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{-# language DuplicateRecordFields #-}
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{-# language LambdaCase #-}
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{-# language MagicHash #-}
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@ -9,19 +10,12 @@
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module Data.ByteArray.Builder
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( -- * Bounded Primitives
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Builder
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, construct
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, fromBounded
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-- * Evaluation
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, run
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, pasteST
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, pasteIO
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, pasteGrowST
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, pasteGrowIO
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, pasteArrayST
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, pasteArrayIO
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-- * Materialized Byte Sequences
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, bytes
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, bytearray
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, byteArray
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, shortTextUtf8
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, shortTextJsonString
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, cstring
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@ -77,9 +71,10 @@ module Data.ByteArray.Builder
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) where
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import Control.Monad.Primitive (primitive_)
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import Control.Monad.ST (ST,stToIO)
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import Control.Monad.ST (ST,stToIO,runST)
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import Control.Monad.ST.Run (runByteArrayST)
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import Data.ByteArray.Builder.Unsafe (Builder(Builder))
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import Data.ByteArray.Builder.Unsafe (Commits(Initial,Mutable,Immutable))
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import Data.ByteArray.Builder.Unsafe (stringUtf8,cstring)
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import Data.ByteString.Short.Internal (ShortByteString(SBS))
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import Data.Bytes.Types (Bytes(Bytes),MutableBytes(MutableBytes))
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@ -90,8 +85,9 @@ import Data.Primitive.ByteArray.Offset (MutableByteArrayOffset(..))
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import Data.Text.Short (ShortText)
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import Data.Word (Word64,Word32,Word16,Word8)
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import GHC.Exts (Int(I#),Char(C#),Int#,State#,ByteArray#,RealWorld,(>=#),(/=#))
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import GHC.Exts ((+#),(-#))
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import GHC.Exts (MutableByteArray#,(+#),(-#),(<#))
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import GHC.ST (ST(ST))
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import Data.Bytes.Chunks (Chunks(..))
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import qualified Arithmetic.Nat as Nat
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import qualified Arithmetic.Types as Arithmetic
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@ -102,105 +98,31 @@ import qualified Data.Vector as V
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import qualified Data.ByteArray.Builder.Bounded as Bounded
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import qualified Data.ByteArray.Builder.Bounded.Unsafe as UnsafeBounded
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-- | Run a builder. An accurate size hint is important for
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-- good performance. The size hint should be slightly greater
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-- than or equal to the actual size.
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-- | Run a builder.
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run ::
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Int -- ^ Hint for upper bound on size
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Int -- ^ Size of initial chunk (use 4080 if uncertain)
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-> Builder -- ^ Builder
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-> ByteArray
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run hint b = runByteArrayST $ do
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let go !n = do
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arr <- PM.newByteArray n
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pasteST b (MutableBytes arr 0 n) >>= \case
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Nothing -> go (n + n + 16)
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Just len -> do
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shrinkMutableByteArray arr len
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PM.unsafeFreezeByteArray arr
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go (max hint 16)
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-> Chunks
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run hint@(I# hint# ) (Builder f) = runST $ do
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MutableByteArray buf0 <- PM.newByteArray hint
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cs <- ST $ \s0 -> case f buf0 0# hint# Initial s0 of
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(# s1, bufX, offX, _, csX #) ->
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(# s1, Mutable bufX offX csX #)
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commitsOntoChunks ChunksNil cs
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-- | Variant of 'pasteArrayST' that runs in 'IO'.
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pasteArrayIO ::
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MutableBytes RealWorld -- ^ Buffer
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-> (a -> Builder) -- ^ Builder
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-> V.Vector a -- ^ Elements to serialize
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-> IO (V.Vector a, MutableBytes RealWorld) -- ^ Shifted vector, shifted buffer
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pasteArrayIO !arr f !xs = stToIO (pasteArrayST arr f xs)
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-- | Fold over a vector, applying the builder to each element until
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-- the buffer cannot accomodate any more.
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pasteArrayST ::
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MutableBytes s -- ^ Buffer
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-> (a -> Builder) -- ^ Builder
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-> V.Vector a -- ^ Elements to serialize
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-> ST s (V.Vector a, MutableBytes s) -- ^ Shifted vector, shifted buffer
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pasteArrayST (MutableBytes arr off0 len0) f !xs0 = do
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let go !xs !ixBufA !lenBufA = if V.length xs > 0
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then do
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let a = V.unsafeHead xs
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pasteST (f a) (MutableBytes arr ixBufA lenBufA) >>= \case
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Nothing -> pure (xs,MutableBytes arr ixBufA lenBufA)
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Just ixBufB ->
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go (V.unsafeTail xs) ixBufB (lenBufA + (ixBufA - ixBufB))
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else pure (xs,MutableBytes arr ixBufA lenBufA)
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go xs0 off0 len0
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-- | Paste the builder into the byte array starting at offset zero.
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-- This repeatedly reallocates the byte array if it cannot accomodate
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-- the builder, replaying the builder each time.
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pasteGrowST ::
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Int -- ^ How many bytes to grow by at a time
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-> Builder
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-> MutableByteArrayOffset s
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-- ^ Initial buffer, used linearly. Do not reuse this argument.
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-> ST s (MutableByteArrayOffset s)
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-- ^ Final buffer that accomodated the builder.
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pasteGrowST !n b !(MutableByteArrayOffset arr0 off0) = do
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let go !arr !sz = pasteST b (MutableBytes arr off0 (sz - off0)) >>= \case
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Nothing -> do
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let szNext = sz + n
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arrNext <- PM.resizeMutableByteArray arr szNext
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go arrNext szNext
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Just ix -> pure (MutableByteArrayOffset{array=arr,offset=ix})
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go arr0 =<< PM.getSizeofMutableByteArray arr0
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-- | Variant of 'pasteGrowST' that runs in 'IO'.
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pasteGrowIO ::
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Int -- ^ How many bytes to grow by at a time
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-> Builder
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-> MutableByteArrayOffset RealWorld
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-- ^ Initial buffer, used linearly. Do not reuse this argument.
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-> IO (MutableByteArrayOffset RealWorld)
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-- ^ Final buffer that accomodated the builder.
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pasteGrowIO !n b !arr = stToIO (pasteGrowST n b arr)
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-- | Execute the builder, pasting its contents into a buffer.
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-- If the buffer is not large enough, this returns 'Nothing'.
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-- Otherwise, it returns the index in the buffer that follows
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-- the payload just written.
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pasteST :: Builder -> MutableBytes s -> ST s (Maybe Int)
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{-# inline pasteST #-}
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pasteST (Builder f) (MutableBytes (MutableByteArray arr) (I# off) (I# len)) =
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ST $ \s0 -> case f arr off len s0 of
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(# s1, r #) -> if Exts.isTrue# (r /=# (-1#))
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then (# s1, Just (I# r) #)
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else (# s1, Nothing #)
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-- | Variant of 'pasteST' that runs in 'IO'.
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pasteIO :: Builder -> MutableBytes RealWorld -> IO (Maybe Int)
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{-# inline pasteIO #-}
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pasteIO b m = stToIO (pasteST b m)
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-- | Constructor for 'Builder' that works on a function with lifted
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-- arguments instead of unlifted ones. This is just as unsafe as the
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-- actual constructor.
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construct :: (forall s. MutableBytes s -> ST s (Maybe Int)) -> Builder
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construct f = Builder
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$ \arr off len s0 ->
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case unST (f (MutableBytes (MutableByteArray arr) (I# off) (I# len))) s0 of
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(# s1, m #) -> case m of
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Nothing -> (# s1, (-1#) #)
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Just (I# n) -> (# s1, n #)
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-- Internal. This freezes all the mutable byte arrays in-place,
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-- so be careful. It also reverses the chunks since everything
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-- is backwards.
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commitsOntoChunks :: Chunks -> Commits s -> ST s Chunks
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commitsOntoChunks !xs Initial = pure xs
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commitsOntoChunks !xs (Immutable arr off len cs) =
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commitsOntoChunks (ChunksCons (Bytes (ByteArray arr) (I# off) (I# len)) xs) cs
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commitsOntoChunks !xs (Mutable buf len cs) = case len of
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0# -> commitsOntoChunks xs cs
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_ -> do
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shrinkMutableByteArray (MutableByteArray buf) (I# len)
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arr <- PM.unsafeFreezeByteArray (MutableByteArray buf)
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commitsOntoChunks (ChunksCons (Bytes arr 0 (I# len)) xs) cs
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-- | Convert a bounded builder to an unbounded one. If the size
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-- is a constant, use @Arithmetic.Nat.constant@ as the first argument
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@ -210,23 +132,51 @@ fromBounded ::
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-> Bounded.Builder n
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-> Builder
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{-# inline fromBounded #-}
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fromBounded n (UnsafeBounded.Builder f) = Builder $ \arr off len s0 ->
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let !(I# req) = Nat.demote n in
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case len >=# req of
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1# -> f arr off s0
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_ -> (# s0, (-1#) #)
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fromBounded n (UnsafeBounded.Builder f) = Builder $ \buf0 off0 len0 cs0 s0 ->
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let !(I# req) = Nat.demote n
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!(# s1, buf1, off1, len1, cs1 #) = case len0 >=# req of
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1# -> (# s0, buf0, off0, len0, cs0 #)
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_ -> let !(I# lenX) = max 4080 (I# req) in
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case Exts.newByteArray# lenX s0 of
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(# sX, bufX #) ->
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(# sX, bufX, 0#, lenX, Mutable buf0 off0 cs0 #)
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in case f buf1 off1 s1 of
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(# s2, off2 #) -> (# s2, buf1, off2, len1 -# (off2 -# off1), cs1 #)
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-- This is a micro-optimization that uses an equality check instead
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-- of an inequality check when the required number of bytes is one.
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-- Use this instead of fromBounded (where possible) leads to marginally
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-- better results in benchmarks.
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fromBoundedOne ::
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Bounded.Builder 1
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-> Builder
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{-# inline fromBoundedOne #-}
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fromBoundedOne (UnsafeBounded.Builder f) = Builder $ \buf0 off0 len0 cs0 s0 ->
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let !(# s1, buf1, off1, len1, cs1 #) = case len0 of
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0# -> case Exts.newByteArray# 4080# s0 of
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(# sX, bufX #) ->
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(# sX, bufX, 0#, 4080#, Mutable buf0 off0 cs0 #)
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_ -> (# s0, buf0, off0, len0, cs0 #)
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in case f buf1 off1 s1 of
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(# s2, off2 #) -> (# s2, buf1, off2, len1 -# (off2 -# off1), cs1 #)
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-- | Create a builder from an unsliced byte sequence.
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bytearray :: ByteArray -> Builder
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bytearray a = bytes (Bytes a 0 (PM.sizeofByteArray a))
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byteArray :: ByteArray -> Builder
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byteArray a = bytes (Bytes a 0 (PM.sizeofByteArray a))
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-- | Create a builder from a sliced byte sequence.
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bytes :: Bytes -> Builder
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bytes (Bytes src soff slen) = construct $ \(MutableBytes arr off len) -> if len >= slen
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then do
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PM.copyByteArray arr off src soff slen
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pure (Just (off + slen))
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else pure Nothing
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bytes (Bytes (ByteArray src# ) (I# soff# ) slen@(I# slen# )) = Builder
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(\buf0 off0 len0 cs0 s0 -> if slen >= 1024
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then case Exts.newByteArray# 0# s0 of
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(# s1, buf1 #) -> (# s1, buf1, 0#, 0#, Immutable src# soff# slen# (Mutable buf0 off0 cs0) #)
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else case len0 <# slen# of
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1# -> case Exts.newByteArray# 4080# s0 of
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(# s1, buf1 #) -> case Exts.copyByteArray# src# soff# buf1 0# slen# s1 of
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s2 -> (# s2, buf1, slen#, 4080# -# slen#, Mutable buf0 off0 cs0 #)
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_ -> let !s1 = Exts.copyByteArray# src# soff# buf0 off0 slen# s0 in
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(# s1, buf0, off0 +# slen#, len0 -# slen#, cs0 #)
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)
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-- | Create a builder from a slice of an array of 'Word8'. There is the same
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-- as 'bytes' but is provided as a convenience for users working with different
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@ -238,31 +188,44 @@ word8Array (PrimArray arr) off len = bytes (Bytes (ByteArray arr) off len)
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-- byte sequence is UTF-8 encoded text.
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slicedUtf8TextJson :: ByteArray# -> Int# -> Int# -> Builder
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{-# inline slicedUtf8TextJson #-}
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slicedUtf8TextJson !src# !soff0# !slen0# = construct $ \(MutableBytes dst doff0 dlen0) ->
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let slen0 = I# slen0#
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in if dlen0 > (2 * slen0) + 2
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then do
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PM.writeByteArray dst doff0 (c2w '"')
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let go !soff !slen !doff = if slen > 0
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then case indexChar8Array (ByteArray src#) soff of
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'\\' -> write2 dst doff '\\' '\\' *> go (soff + 1) (slen - 1) (doff + 2)
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'\"' -> write2 dst doff '\\' '\"' *> go (soff + 1) (slen - 1) (doff + 2)
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'\n' -> write2 dst doff '\\' 'n' *> go (soff + 1) (slen - 1) (doff + 2)
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'\r' -> write2 dst doff '\\' 'r' *> go (soff + 1) (slen - 1) (doff + 2)
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'\t' -> write2 dst doff '\\' 't' *> go (soff + 1) (slen - 1) (doff + 2)
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c -> if c >= '\x20'
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then PM.writeByteArray dst doff (c2w c) *> go (soff + 1) (slen - 1) (doff + 1)
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else do
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write2 dst doff '\\' 'u'
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doff' <- UnsafeBounded.pasteST
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(Bounded.word16PaddedUpperHex (fromIntegral (c2w c)))
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dst (doff + 2)
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go (soff + 1) (slen - 1) doff'
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else pure doff
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doffRes <- go (I# soff0#) (I# slen0#) (doff0 + 1)
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PM.writeByteArray dst doffRes (c2w '"')
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pure (Just (doffRes + 1))
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else pure Nothing
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slicedUtf8TextJson !src# !soff0# !slen0# = fromFunction reqLen $ \dst doff0 -> do
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PM.writeByteArray dst doff0 (c2w '"')
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let go !soff !slen !doff = if slen > 0
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then case indexChar8Array (ByteArray src#) soff of
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'\\' -> write2 dst doff '\\' '\\' *> go (soff + 1) (slen - 1) (doff + 2)
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'\"' -> write2 dst doff '\\' '\"' *> go (soff + 1) (slen - 1) (doff + 2)
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'\n' -> write2 dst doff '\\' 'n' *> go (soff + 1) (slen - 1) (doff + 2)
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'\r' -> write2 dst doff '\\' 'r' *> go (soff + 1) (slen - 1) (doff + 2)
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'\t' -> write2 dst doff '\\' 't' *> go (soff + 1) (slen - 1) (doff + 2)
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c -> if c >= '\x20'
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then PM.writeByteArray dst doff (c2w c) *> go (soff + 1) (slen - 1) (doff + 1)
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else do
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write2 dst doff '\\' 'u'
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doff' <- UnsafeBounded.pasteST
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(Bounded.word16PaddedUpperHex (fromIntegral (c2w c)))
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dst (doff + 2)
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go (soff + 1) (slen - 1) doff'
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else pure doff
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doffRes <- go (I# soff0#) (I# slen0#) (doff0 + 1)
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PM.writeByteArray dst doffRes (c2w '"')
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pure (doffRes + 1)
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where
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slen0 = I# slen0#
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reqLen = (2 * slen0) + 2
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-- | Constructor for 'Builder' that works on a function with lifted
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-- arguments instead of unlifted ones. This is just as unsafe as the
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-- actual constructor.
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fromFunction :: Int -> (forall s. MutableByteArray s -> Int -> ST s Int) -> Builder
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fromFunction (I# req) f = Builder $ \buf0 off0 len0 cs0 s0 ->
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let !(# s1, buf1, off1, len1, cs1 #) = case len0 >=# req of
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1# -> (# s0, buf0, off0, len0, cs0 #)
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_ -> let !(I# lenX) = max 4080 (I# req) in
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case Exts.newByteArray# lenX s0 of
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(# sX, bufX #) ->
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(# sX, bufX, 0#, lenX, Mutable buf0 off0 cs0 #)
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in case unST (f (MutableByteArray buf1) (I# off1)) s1 of
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(# s2, I# off2 #) -> (# s2, buf1, off2, len1 -# (off2 -# off1), cs1 #)
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-- Internal. Write two characters in the ASCII plane to a byte array.
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write2 :: MutableByteArray s -> Int -> Char -> Char -> ST s ()
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@ -420,7 +383,7 @@ word8PaddedUpperHex w =
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-- | Encode an ASCII char.
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-- Precondition: Input must be an ASCII character. This is not checked.
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ascii :: Char -> Builder
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ascii c = fromBounded Nat.constant (Bounded.ascii c)
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ascii c = fromBoundedOne (Bounded.ascii c)
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-- | Encode an UTF8 char. This only uses as much space as is required.
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char :: Char -> Builder
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@ -475,7 +438,7 @@ word16BE w = fromBounded Nat.constant (Bounded.word16BE w)
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-- | Requires exactly 1 byte.
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word8 :: Word8 -> Builder
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word8 w = fromBounded Nat.constant (Bounded.word8 w)
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word8 w = fromBoundedOne (Bounded.word8 w)
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-- | Prefix a builder with its size in bytes. This size is
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-- presented as a big-endian 32-bit word. The need to prefix
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@ -490,35 +453,54 @@ word8 w = fromBounded Nat.constant (Bounded.word8 w)
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-- However, using 'consLength32BE' is much more efficient here
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-- since it only materializes the 'ByteArray' once.
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consLength32BE :: Builder -> Builder
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consLength32BE (Builder f) = Builder $ \arr off len s0 -> case len >=# 4# of
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1# -> case f arr (off +# 4# ) (len -# 4# ) s0 of
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(# s1, r #) -> case r of
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(-1#) -> (# s1, (-1#) #)
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_ ->
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let ST g = UnsafeBounded.pasteST
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(Bounded.word32BE (fromIntegral ((I# r - I# off) - 4)))
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(MutableByteArray arr)
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(I# off)
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in case g s1 of
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(# s2, _ #) -> (# s2, r #)
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_ -> (# s0, (-1#) #)
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consLength32BE (Builder f) = Builder $ \buf0 off0 len0 cs0 s0 ->
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let !(# s1, buf1, off1, len1, cs1 #) = case len0 >=# 4# of
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1# -> (# s0, buf0, off0, len0, cs0 #)
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_ -> case Exts.newByteArray# 4080# s0 of
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(# sX, bufX #) ->
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(# sX, bufX, 0#, 4080#, Mutable buf0 off0 cs0 #)
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in case f buf1 (off1 +# 4# ) (len1 -# 4# ) cs1 s1 of
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(# s2, buf2, off2, len2, cs2 #) ->
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let !dist = case Exts.sameMutableByteArray# buf1 buf2 of
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1# -> off2 -# off1
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_ -> commitDistance buf1 off2 cs2 -# off1
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ST g = UnsafeBounded.pasteST
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(Bounded.word32BE (fromIntegral (I# (dist -# 4# ))))
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(MutableByteArray buf1)
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(I# off1)
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||||
in case g s2 of
|
||||
(# s3, _ #) -> (# s3, buf2, off2, len2, cs2 #)
|
||||
|
||||
|
||||
-- | Prefix a builder with its size in bytes. This size is
|
||||
-- presented as a big-endian 64-bit word. See 'consLength32BE'.
|
||||
consLength64BE :: Builder -> Builder
|
||||
consLength64BE (Builder f) = Builder $ \arr off len s0 -> case len >=# 8# of
|
||||
1# -> case f arr (off +# 8# ) (len -# 8# ) s0 of
|
||||
(# s1, r #) -> case r of
|
||||
(-1#) -> (# s1, (-1#) #)
|
||||
_ ->
|
||||
let ST g = UnsafeBounded.pasteST
|
||||
(Bounded.word64BE (fromIntegral ((I# r - I# off) - 8)))
|
||||
(MutableByteArray arr)
|
||||
(I# off)
|
||||
in case g s1 of
|
||||
(# s2, _ #) -> (# s2, r #)
|
||||
_ -> (# s0, (-1#) #)
|
||||
consLength64BE (Builder f) = Builder $ \buf0 off0 len0 cs0 s0 ->
|
||||
let !(# s1, buf1, off1, len1, cs1 #) = case len0 >=# 8# of
|
||||
1# -> (# s0, buf0, off0, len0, cs0 #)
|
||||
_ -> case Exts.newByteArray# 4080# s0 of
|
||||
(# sX, bufX #) ->
|
||||
(# sX, bufX, 0#, 4080#, Mutable buf0 off0 cs0 #)
|
||||
in case f buf1 (off1 +# 8# ) (len1 -# 8# ) cs1 s1 of
|
||||
(# s2, buf2, off2, len2, cs2 #) ->
|
||||
let !dist = case Exts.sameMutableByteArray# buf1 buf2 of
|
||||
1# -> off2 -# off1
|
||||
_ -> commitDistance buf1 off2 cs2 -# off1
|
||||
ST g = UnsafeBounded.pasteST
|
||||
(Bounded.word64BE (fromIntegral (I# (dist -# 8# ))))
|
||||
(MutableByteArray buf1)
|
||||
(I# off1)
|
||||
in case g s2 of
|
||||
(# s3, _ #) -> (# s3, buf2, off2, len2, cs2 #)
|
||||
|
||||
commitDistance :: MutableByteArray# s -> Int# -> Commits s -> Int#
|
||||
commitDistance _ !_ Initial = error "chunkDistance: chunk not found"
|
||||
commitDistance target !n (Immutable _ _ len cs) =
|
||||
commitDistance target (n +# len) cs
|
||||
commitDistance target !n (Mutable buf len cs) =
|
||||
case Exts.sameMutableByteArray# target buf of
|
||||
1# -> n +# len
|
||||
_ -> commitDistance target (n +# len) cs
|
||||
|
||||
-- ShortText is already UTF-8 encoded. This is a no-op.
|
||||
shortTextToByteArray :: ShortText -> ByteArray
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue