{-# LANGUAGE BangPatterns, CPP, OverloadedStrings #-}
{-# OPTIONS_GHC -fno-warn-unused-binds #-}
module AesonBP where
import Data.ByteString.Builder
(Builder, byteString, toLazyByteString, charUtf8, word8)
#if !MIN_VERSION_base(4,8,0)
import Control.Applicative ((*>), (<$>), (<*), pure)
import Data.Monoid (mappend, mempty)
#endif
import Control.Applicative (liftA2)
import Control.DeepSeq (NFData(..))
import Control.Monad (forM)
import Data.Bits ((.|.), shiftL)
import Data.ByteString (ByteString)
import Data.Char (chr)
import Data.List (sort)
import Data.Scientific (Scientific)
import Data.Text (Text)
import Data.Text.Encoding (decodeUtf8')
import Data.Vector as Vector (Vector, foldl', fromList)
import Data.Word (Word8)
import System.Directory (getDirectoryContents)
import System.FilePath ((</>), dropExtension)
import qualified Data.Attoparsec.Zepto as Z
import Data.Binary.Get (Get)
import qualified Data.Binary.Parser as BP
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Unsafe as B
import qualified Data.HashMap.Strict as H
import System.Directory (doesDirectoryExist)
import Aeson (Value(..))
#define BACKSLASH 92
#define CLOSE_CURLY 125
#define CLOSE_SQUARE 93
#define COMMA 44
#define COLON 58
#define DOUBLE_QUOTE 34
#define OPEN_CURLY 123
#define OPEN_SQUARE 91
#define C_0 48
#define C_9 57
#define C_A 65
#define C_F 70
#define C_a 97
#define C_f 102
#define C_n 110
#define C_t 116
pathTo :: String -> IO FilePath
pathTo wat = do
exists <- doesDirectoryExist "bench"
return $ if exists
then "bench" </> wat
else wat
data Result a = Error String
| Success a
deriving (Eq, Show)
-- | A JSON \"object\" (key\/value map).
type Object = H.HashMap Text Value
-- | A JSON \"array\" (sequence).
type Array = Vector Value
-- | Parse a top-level JSON value. This must be either an object or
-- an array, per RFC 4627.
--
-- The conversion of a parsed value to a Haskell value is deferred
-- until the Haskell value is needed. This may improve performance if
-- only a subset of the results of conversions are needed, but at a
-- cost in thunk allocation.
json :: Get Value
json = json_ object_ array_
-- | Parse a top-level JSON value. This must be either an object or
-- an array, per RFC 4627.
--
-- This is a strict version of 'json' which avoids building up thunks
-- during parsing; it performs all conversions immediately. Prefer
-- this version if most of the JSON data needs to be accessed.
json' :: Get Value
json' = json_ object_' array_'
json_ :: Get Value -> Get Value -> Get Value
json_ obj ary = do
w <- BP.skipSpaces *> BP.satisfy (\w -> w == OPEN_CURLY || w == OPEN_SQUARE)
if w == OPEN_CURLY
then obj
else ary
{-# INLINE json_ #-}
object_ :: Get Value
object_ = {-# SCC "object_" #-} Object <$> objectValues jstring value
object_' :: Get Value
object_' = {-# SCC "object_'" #-} do
!vals <- objectValues jstring' value'
return (Object vals)
where
jstring' = do
!s <- jstring
return s
objectValues :: Get Text -> Get Value -> Get (H.HashMap Text Value)
objectValues str val = do
BP.skipSpaces
let pair = liftA2 (,) (str <* BP.skipSpaces) (BP.word8 COLON *> BP.skipSpaces *> val)
H.fromList <$> commaSeparated pair CLOSE_CURLY
{-# INLINE objectValues #-}
array_ :: Get Value
array_ = {-# SCC "array_" #-} Array <$> arrayValues value
array_' :: Get Value
array_' = {-# SCC "array_'" #-} do
!vals <- arrayValues value'
return (Array vals)
commaSeparated :: Get a -> Word8 -> Get [a]
commaSeparated item endByte = do
w <- BP.peek
if w == endByte
then BP.skipN 1 >> return []
else loop
where
loop = do
v <- item <* BP.skipSpaces
ch <- BP.satisfy $ \w -> w == COMMA || w == endByte
if ch == COMMA
then BP.skipSpaces >> (v:) <$> loop
else return [v]
{-# INLINE commaSeparated #-}
arrayValues :: Get Value -> Get (Vector Value)
arrayValues val = do
BP.skipSpaces
Vector.fromList <$> commaSeparated val CLOSE_SQUARE
{-# INLINE arrayValues #-}
-- | Parse any JSON value. You should usually 'json' in preference to
-- this function, as this function relaxes the object-or-array
-- requirement of RFC 4627.
--
-- In particular, be careful in using this function if you think your
-- code might interoperate with Javascript. A naïve Javascript
-- library that parses JSON data using @eval@ is vulnerable to attack
-- unless the encoded data represents an object or an array. JSON
-- implementations in other languages conform to that same restriction
-- to preserve interoperability and security.
value :: Get Value
value = do
w <- BP.peek
case w of
DOUBLE_QUOTE -> BP.skipN 1 *> (String <$> jstring_)
OPEN_CURLY -> BP.skipN 1 *> object_
OPEN_SQUARE -> BP.skipN 1 *> array_
C_f -> BP.string "false" *> pure (Bool False)
C_t -> BP.string "true" *> pure (Bool True)
C_n -> BP.string "null" *> pure Null
_ | w >= 48 && w <= 57 || w == 45
-> Number <$> BP.scientific
| otherwise -> fail "not a valid json value"
-- | Strict version of 'value'. See also 'json''.
value' :: Get Value
value' = do
w <- BP.peek
case w of
DOUBLE_QUOTE -> do
!s <- BP.skipN 1 *> jstring_
return (String s)
OPEN_CURLY -> BP.skipN 1 *> object_'
OPEN_SQUARE -> BP.skipN 1 *> array_'
C_f -> BP.string "false" *> pure (Bool False)
C_t -> BP.string "true" *> pure (Bool True)
C_n -> BP.string "null" *> pure Null
_ | w >= 48 && w <= 57 || w == 45
-> do
!n <- BP.scientific
return (Number n)
| otherwise -> fail "not a valid json value"
-- | Parse a quoted JSON string.
jstring :: Get Text
jstring = BP.word8 DOUBLE_QUOTE *> jstring_
-- | Parse a string without a leading quote.
jstring_ :: Get Text
jstring_ = {-# SCC "jstring_" #-} do
s <- BP.scan False $ \s c -> if s then Just False
else if c == DOUBLE_QUOTE
then Nothing
else Just (c == BACKSLASH)
BP.word8 DOUBLE_QUOTE
s1 <- if BACKSLASH `B.elem` s
then case Z.parse unescape s of
Right r -> return r
Left err -> fail err
else return s
case decodeUtf8' s1 of
Right r -> return r
Left err -> fail $ show err
{-# INLINE jstring_ #-}
unescape :: Z.Parser ByteString
unescape = toByteString <$> go mempty where
go acc = do
h <- Z.takeWhile (/=BACKSLASH)
let rest = do
start <- Z.take 2
let !slash = B.unsafeHead start
!t = B.unsafeIndex start 1
escape = case B.findIndex (==t) "\"\\/ntbrfu" of
Just i -> i
_ -> 255
if slash /= BACKSLASH || escape == 255
then fail "invalid JSON escape sequence"
else do
let cont m = go (acc `mappend` byteString h `mappend` m)
{-# INLINE cont #-}
if t /= 117 -- 'u'
then cont (word8 (B.unsafeIndex mapping escape))
else do
a <- hexQuad
if a < 0xd800 || a > 0xdfff
then cont (charUtf8 (chr a))
else do
b <- Z.string "\\u" *> hexQuad
if a <= 0xdbff && b >= 0xdc00 && b <= 0xdfff
then let !c = ((a - 0xd800) `shiftL` 10) +
(b - 0xdc00) + 0x10000
in cont (charUtf8 (chr c))
else fail "invalid UTF-16 surrogates"
done <- Z.atEnd
if done
then return (acc `mappend` byteString h)
else rest
mapping = "\"\\/\n\t\b\r\f"
hexQuad :: Z.Parser Int
hexQuad = do
s <- Z.take 4
let hex n | w >= C_0 && w <= C_9 = w - C_0
| w >= C_a && w <= C_f = w - 87
| w >= C_A && w <= C_F = w - 55
| otherwise = 255
where w = fromIntegral $ B.unsafeIndex s n
a = hex 0; b = hex 1; c = hex 2; d = hex 3
if (a .|. b .|. c .|. d) /= 255
then return $! d .|. (c `shiftL` 4) .|. (b `shiftL` 8) .|. (a `shiftL` 12)
else fail "invalid hex escape"
-- $lazy
--
-- The 'json' and 'value' parsers decouple identification from
-- conversion. Identification occurs immediately (so that an invalid
-- JSON document can be rejected as early as possible), but conversion
-- to a Haskell value is deferred until that value is needed.
--
-- This decoupling can be time-efficient if only a smallish subset of
-- elements in a JSON value need to be inspected, since the cost of
-- conversion is zero for uninspected elements. The trade off is an
-- increase in memory usage, due to allocation of thunks for values
-- that have not yet been converted.
-- $strict
--
-- The 'json'' and 'value'' parsers combine identification with
-- conversion. They consume more CPU cycles up front, but have a
-- smaller memory footprint.
-- | Parse a top-level JSON value followed by optional whitespace and
-- end-of-input. See also: 'json'.
jsonEOF :: Get Value
jsonEOF = json <* BP.skipSpaces
-- | Parse a top-level JSON value followed by optional whitespace and
-- end-of-input. See also: 'json''.
jsonEOF' :: Get Value
jsonEOF' = json' <* BP.skipSpaces
toByteString :: Builder -> ByteString
toByteString = L.toStrict . toLazyByteString
{-# INLINE toByteString #-}