Fast.hs

module Data.Succinct.Json.Standard.Cursor.Fast
  ( Cursor
  , fromByteString
  , fromByteStringViaBlanking
  , fromByteStringViaSimd
  , fromForeignRegion
  , fromString
  , fromBsIbBp
  , simdToIbBp
  ) where

import Data.Succinct.Json.Standard.Cursor.Generic
import Data.Succinct.Json.Standard.Cursor.IbBp
import Data.Succinct.Json.Standard.Cursor.Specific
import Data.Succinct.RankSelect.CsPoppy1
import Foreign.ForeignPtr

import qualified Data.ByteString                         as BS
import qualified Data.ByteString.Char8                   as BSC
import qualified Data.ByteString.Internal                as BSI
import qualified Data.Succinct.BalancedParens.RangeMin   as RM
import qualified Data.Succinct.Json.Standard.Cursor.IbBp as J
import qualified HaskellWorks.Data.FromForeignRegion     as F

data Fast

instance SpecificCursor Fast where
  type CursorOf Fast = Cursor

type Cursor = GenericCursor BS.ByteString CsPoppy1 (RM.RangeMin CsPoppy1)

fromBsIbBp :: BS.ByteString -> IbBp -> Cursor
fromBsIbBp bs ibBp = GenericCursor
  { cursorText      = bs
  , interests       = makeCsPoppy ibPart
  , balancedParens  = RM.mkRangeMin (makeCsPoppy bpPart)
  , cursorRank      = 1
  }
  where J.IbBp ibPart bpPart = ibBp

-- | Load a 'Cursor' from a 'ByteString'
fromByteString :: BS.ByteString -> Cursor
fromByteString = fromByteStringViaBlanking
{-# DEPRECATED fromByteString "Use one of the other fromByteString* functions" #-}

-- | Load a 'Cursor' from a 'ByteString' via the blanking process.
-- This has reasonable performance, but uses a lot of memory due to
-- the lack of streaming
fromByteStringViaBlanking :: BS.ByteString -> Cursor
fromByteStringViaBlanking bs = fromBsIbBp bs (J.slowToIbBp bs)

-- | Load a 'Cursor' from a 'ByteString' via the blanking via `simd`
-- This has fast performance and streaming, but is only available
-- recent x86 platforms
fromByteStringViaSimd :: BS.ByteString -> Cursor
fromByteStringViaSimd jsonBs = fromBsIbBp jsonBs (simdToIbBp jsonBs)

fromForeignRegion :: F.ForeignRegion -> Cursor
fromForeignRegion (fptr, offset, size) = fromByteString (BSI.fromForeignPtr (castForeignPtr fptr) offset size)

fromString :: String -> Cursor
fromString = fromByteString . BSC.pack