git-annex/Key.hs
Joey Hess 19e78816f0
convert Key to ShortByteString
This adds the overhead of a copy when serializing and deserializing keys.
I have not benchmarked much, but runtimes seem barely changed at all by that.

When a lot of keys are in memory, it improves memory use.

And, it prevents keys sometimes getting PINNED in memory and failing to GC,
which is a problem ByteString has sometimes. In particular, git-annex sync
from a borg special remote had that problem and this improved its memory
use by a large amount.

Sponsored-by: Shae Erisson on Patreon
2021-10-05 20:20:08 -04:00

108 lines
2.8 KiB
Haskell

{- git-annex Keys
-
- Copyright 2011-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Key (
Key,
KeyData(..),
AssociatedFile(..),
fromKey,
mkKey,
alterKey,
keyParser,
serializeKey,
serializeKey',
deserializeKey,
deserializeKey',
nonChunkKey,
chunkKeyOffset,
isChunkKey,
isKeyPrefix,
splitKeyNameExtension,
prop_isomorphic_key_encode
) where
import qualified Data.Text as T
import qualified Data.ByteString as S
import qualified Data.ByteString.Short as S (toShort, fromShort)
import qualified Data.Attoparsec.ByteString as A
import Common
import Types.Key
import Utility.QuickCheck
import Utility.Bloom
import Utility.Aeson
import qualified Utility.SimpleProtocol as Proto
-- Gets the parent of a chunk key.
nonChunkKey :: Key -> Key
nonChunkKey k
| fromKey keyChunkSize k == Nothing && fromKey keyChunkNum k == Nothing = k
| otherwise = alterKey k $ \d -> d
{ keyChunkSize = Nothing
, keyChunkNum = Nothing
}
-- Where a chunk key is offset within its parent.
chunkKeyOffset :: Key -> Maybe Integer
chunkKeyOffset k = (*)
<$> fromKey keyChunkSize k
<*> (pred <$> fromKey keyChunkNum k)
isChunkKey :: Key -> Bool
isChunkKey k = isJust (fromKey keyChunkSize k) && isJust (fromKey keyChunkNum k)
serializeKey :: Key -> String
serializeKey = decodeBS . serializeKey'
serializeKey' :: Key -> S.ByteString
serializeKey' = S.fromShort . keySerialization
deserializeKey :: String -> Maybe Key
deserializeKey = deserializeKey' . encodeBS
deserializeKey' :: S.ByteString -> Maybe Key
deserializeKey' = eitherToMaybe . A.parseOnly keyParser
instance Arbitrary KeyData where
arbitrary = Key
<$> (S.toShort . encodeBS <$> (listOf1 $ elements $ ['A'..'Z'] ++ ['a'..'z'] ++ ['0'..'9'] ++ "-_\r\n \t"))
<*> (parseKeyVariety . encodeBS <$> (listOf1 $ elements ['A'..'Z'])) -- BACKEND
<*> ((abs <$>) <$> arbitrary) -- size cannot be negative
<*> ((abs . fromInteger <$>) <$> arbitrary) -- mtime cannot be negative
<*> ((abs <$>) <$> arbitrary) -- chunksize cannot be negative
<*> ((succ . abs <$>) <$> arbitrary) -- chunknum cannot be 0 or negative
instance Arbitrary AssociatedFile where
arbitrary = AssociatedFile
. fmap (toRawFilePath . fromTestableFilePath)
<$> arbitrary
instance Arbitrary Key where
arbitrary = mkKey . const <$> arbitrary
instance Hashable Key where
hashIO32 = hashIO32 . serializeKey'
hashIO64 = hashIO64 . serializeKey'
instance ToJSON' Key where
toJSON' = toJSON' . serializeKey
instance FromJSON Key where
parseJSON (String t) = maybe mempty pure $ deserializeKey $ T.unpack t
parseJSON _ = mempty
instance Proto.Serializable Key where
serialize = serializeKey
deserialize = deserializeKey
prop_isomorphic_key_encode :: Key -> Bool
prop_isomorphic_key_encode k = Just k == (deserializeKey . serializeKey) k