git-annex/Backend/Hash.hs
Joey Hess 067aabdd48
wip RawFilePath 2x git-annex find speedup
Finally builds (oh the agoncy of making it build), but still very
unmergable, only Command.Find is included and lots of stuff is badly
hacked to make it compile.

Benchmarking vs master, this git-annex find is significantly faster!
Specifically:

	num files	old	new	speedup
	48500		4.77	3.73	28%
	12500		1.36	1.02	66%
	20		0.075	0.074	0% (so startup time is unchanged)

That's without really finishing the optimization. Things still to do:

* Eliminate all the fromRawFilePath, toRawFilePath, encodeBS,
  decodeBS conversions.
* Use versions of IO actions like getFileStatus that take a RawFilePath.
* Eliminate some Data.ByteString.Lazy.toStrict, which is a slow copy.
* Use ByteString for parsing git config to speed up startup.

It's likely several of those will speed up git-annex find further.
And other commands will certianly benefit even more.
2019-11-26 16:01:58 -04:00

301 lines
9.6 KiB
Haskell

{- git-annex hashing backends
-
- Copyright 2011-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
module Backend.Hash (
backends,
testKeyBackend,
keyHash,
) where
import Annex.Common
import qualified Annex
import Types.Key
import Types.Backend
import Types.KeySource
import Utility.Hash
import Utility.Metered
import qualified Data.ByteString as S
import qualified Data.ByteString.Char8 as S8
import qualified Data.ByteString.Lazy as L
import Data.Char
import Control.DeepSeq
import Control.Exception (evaluate)
data Hash
= MD5Hash
| SHA1Hash
| SHA2Hash HashSize
| SHA3Hash HashSize
| SkeinHash HashSize
| Blake2bHash HashSize
| Blake2bpHash HashSize
| Blake2sHash HashSize
| Blake2spHash HashSize
{- Order is slightly significant; want SHA256 first, and more general
- sizes earlier. -}
hashes :: [Hash]
hashes = concat
[ map (SHA2Hash . HashSize) [256, 512, 224, 384]
, map (SHA3Hash . HashSize) [256, 512, 224, 384]
, map (SkeinHash . HashSize) [256, 512]
, map (Blake2bHash . HashSize) [256, 512, 160, 224, 384]
, map (Blake2bpHash . HashSize) [512]
, map (Blake2sHash . HashSize) [256, 160, 224]
, map (Blake2spHash . HashSize) [256, 224]
, [SHA1Hash]
, [MD5Hash]
]
{- The SHA256E backend is the default, so genBackendE comes first. -}
backends :: [Backend]
backends = concatMap (\h -> [genBackendE h, genBackend h]) hashes
genBackend :: Hash -> Backend
genBackend hash = Backend
{ backendVariety = hashKeyVariety hash (HasExt False)
, getKey = keyValue hash
, verifyKeyContent = Just $ checkKeyChecksum hash
, canUpgradeKey = Just needsUpgrade
, fastMigrate = Just trivialMigrate
, isStableKey = const True
}
genBackendE :: Hash -> Backend
genBackendE hash = (genBackend hash)
{ backendVariety = hashKeyVariety hash (HasExt True)
, getKey = keyValueE hash
}
hashKeyVariety :: Hash -> HasExt -> KeyVariety
hashKeyVariety MD5Hash he = MD5Key he
hashKeyVariety SHA1Hash he = SHA1Key he
hashKeyVariety (SHA2Hash size) he = SHA2Key size he
hashKeyVariety (SHA3Hash size) he = SHA3Key size he
hashKeyVariety (SkeinHash size) he = SKEINKey size he
hashKeyVariety (Blake2bHash size) he = Blake2bKey size he
hashKeyVariety (Blake2bpHash size) he = Blake2bpKey size he
hashKeyVariety (Blake2sHash size) he = Blake2sKey size he
hashKeyVariety (Blake2spHash size) he = Blake2spKey size he
{- A key is a hash of its contents. -}
keyValue :: Hash -> KeySource -> MeterUpdate -> Annex (Maybe Key)
keyValue hash source meterupdate = do
let file = contentLocation source
filesize <- liftIO $ getFileSize file
s <- hashFile hash file meterupdate
return $ Just $ mkKey $ \k -> k
{ keyName = encodeBS s
, keyVariety = hashKeyVariety hash (HasExt False)
, keySize = Just filesize
}
{- Extension preserving keys. -}
keyValueE :: Hash -> KeySource -> MeterUpdate -> Annex (Maybe Key)
keyValueE hash source meterupdate =
keyValue hash source meterupdate >>= maybe (return Nothing) addE
where
addE k = do
maxlen <- annexMaxExtensionLength <$> Annex.getGitConfig
let ext = selectExtension maxlen (keyFilename source)
return $ Just $ alterKey k $ \d -> d
{ keyName = keyName d <> encodeBS ext
, keyVariety = hashKeyVariety hash (HasExt True)
}
selectExtension :: Maybe Int -> FilePath -> String
selectExtension maxlen f
| null es = ""
| otherwise = intercalate "." ("":es)
where
es = filter (not . null) $ reverse $
take 2 $ filter (all validInExtension) $
takeWhile shortenough $
reverse $ splitc '.' $ takeExtensions f
shortenough e = length e <= fromMaybe maxExtensionLen maxlen
maxExtensionLen :: Int
maxExtensionLen = 4 -- long enough for "jpeg"
{- A key's checksum is checked during fsck when it's content is present
- except for in fast mode. -}
checkKeyChecksum :: Hash -> Key -> FilePath -> Annex Bool
checkKeyChecksum hash key file = catchIOErrorType HardwareFault hwfault $ do
fast <- Annex.getState Annex.fast
exists <- liftIO $ doesFileExist file
case (exists, fast) of
(True, False) -> do
showAction "checksum"
check <$> hashFile hash file nullMeterUpdate
_ -> return True
where
expected = decodeBS (keyHash key)
check s
| s == expected = True
{- A bug caused checksums to be prefixed with \ in some
- cases; still accept these as legal now that the bug has been
- fixed. -}
| '\\' : s == expected = True
| otherwise = False
hwfault e = do
warning $ "hardware fault: " ++ show e
return False
keyHash :: Key -> S.ByteString
keyHash = fst . splitKeyNameExtension
validInExtension :: Char -> Bool
validInExtension c
| isAlphaNum c = True
| c == '.' = True
| otherwise = False
{- Upgrade keys that have the \ prefix on their hash due to a bug, or
- that contain non-alphanumeric characters in their extension.
-
- Also, for a while migrate from eg SHA256E to SHA256 resulted in a SHA256
- key that contained an extension inside its keyName. Upgrade those
- keys, removing the extension.
-}
needsUpgrade :: Key -> Bool
needsUpgrade key = or
[ "\\" `S8.isPrefixOf` keyHash key
, any (not . validInExtension) (decodeBS $ snd $ splitKeyNameExtension key)
, not (hasExt (fromKey keyVariety key)) && keyHash key /= fromKey keyName key
]
trivialMigrate :: Key -> Backend -> AssociatedFile -> Annex (Maybe Key)
trivialMigrate oldkey newbackend afile = trivialMigrate' oldkey newbackend afile
<$> (annexMaxExtensionLength <$> Annex.getGitConfig)
trivialMigrate' :: Key -> Backend -> AssociatedFile -> Maybe Int -> Maybe Key
trivialMigrate' oldkey newbackend afile maxextlen
{- Fast migration from hashE to hash backend. -}
| migratable && hasExt oldvariety = Just $ alterKey oldkey $ \d -> d
{ keyName = keyHash oldkey
, keyVariety = newvariety
}
{- Fast migration from hash to hashE backend. -}
| migratable && hasExt newvariety = case afile of
AssociatedFile Nothing -> Nothing
AssociatedFile (Just file) -> Just $ alterKey oldkey $ \d -> d
{ keyName = keyHash oldkey
<> encodeBS' (selectExtension maxextlen (fromRawFilePath file))
, keyVariety = newvariety
}
{- Upgrade to fix bad previous migration that created a
- non-extension preserving key, with an extension
- in its keyName. -}
| newvariety == oldvariety && not (hasExt oldvariety) &&
keyHash oldkey /= fromKey keyName oldkey =
Just $ alterKey oldkey $ \d -> d
{ keyName = keyHash oldkey
}
| otherwise = Nothing
where
migratable = oldvariety /= newvariety
&& sameExceptExt oldvariety newvariety
oldvariety = fromKey keyVariety oldkey
newvariety = backendVariety newbackend
hashFile :: Hash -> FilePath -> MeterUpdate -> Annex String
hashFile hash file meterupdate =
liftIO $ withMeteredFile file meterupdate $ \b -> do
let h = hasher b
-- Force full evaluation of hash so whole file is read
-- before returning.
evaluate (rnf h)
return h
where
hasher = case hash of
MD5Hash -> md5Hasher
SHA1Hash -> sha1Hasher
SHA2Hash hashsize -> sha2Hasher hashsize
SHA3Hash hashsize -> sha3Hasher hashsize
SkeinHash hashsize -> skeinHasher hashsize
Blake2bHash hashsize -> blake2bHasher hashsize
Blake2bpHash hashsize -> blake2bpHasher hashsize
Blake2sHash hashsize -> blake2sHasher hashsize
Blake2spHash hashsize -> blake2spHasher hashsize
sha2Hasher :: HashSize -> (L.ByteString -> String)
sha2Hasher (HashSize hashsize)
| hashsize == 256 = use sha2_256
| hashsize == 224 = use sha2_224
| hashsize == 384 = use sha2_384
| hashsize == 512 = use sha2_512
| otherwise = error $ "unsupported SHA size " ++ show hashsize
where
use hasher = show . hasher
sha3Hasher :: HashSize -> (L.ByteString -> String)
sha3Hasher (HashSize hashsize)
| hashsize == 256 = show . sha3_256
| hashsize == 224 = show . sha3_224
| hashsize == 384 = show . sha3_384
| hashsize == 512 = show . sha3_512
| otherwise = error $ "unsupported SHA3 size " ++ show hashsize
skeinHasher :: HashSize -> (L.ByteString -> String)
skeinHasher (HashSize hashsize)
| hashsize == 256 = show . skein256
| hashsize == 512 = show . skein512
| otherwise = error $ "unsupported SKEIN size " ++ show hashsize
blake2bHasher :: HashSize -> (L.ByteString -> String)
blake2bHasher (HashSize hashsize)
| hashsize == 256 = show . blake2b_256
| hashsize == 512 = show . blake2b_512
| hashsize == 160 = show . blake2b_160
| hashsize == 224 = show . blake2b_224
| hashsize == 384 = show . blake2b_384
| otherwise = error $ "unsupported BLAKE2B size " ++ show hashsize
blake2bpHasher :: HashSize -> (L.ByteString -> String)
blake2bpHasher (HashSize hashsize)
| hashsize == 512 = show . blake2bp_512
| otherwise = error $ "unsupported BLAKE2BP size " ++ show hashsize
blake2sHasher :: HashSize -> (L.ByteString -> String)
blake2sHasher (HashSize hashsize)
| hashsize == 256 = show . blake2s_256
| hashsize == 160 = show . blake2s_160
| hashsize == 224 = show . blake2s_224
| otherwise = error $ "unsupported BLAKE2S size " ++ show hashsize
blake2spHasher :: HashSize -> (L.ByteString -> String)
blake2spHasher (HashSize hashsize)
| hashsize == 256 = show . blake2sp_256
| hashsize == 224 = show . blake2sp_224
| otherwise = error $ "unsupported BLAKE2SP size " ++ show hashsize
sha1Hasher :: L.ByteString -> String
sha1Hasher = show . sha1
md5Hasher :: L.ByteString -> String
md5Hasher = show . md5
{- A varient of the SHA256E backend, for testing that needs special keys
- that cannot collide with legitimate keys in the repository.
-
- This is accomplished by appending a special extension to the key,
- that is not one that selectExtension would select (due to being too
- long).
-}
testKeyBackend :: Backend
testKeyBackend =
let b = genBackendE (SHA2Hash (HashSize 256))
in b { getKey = \ks p -> (fmap addE) <$> getKey b ks p }
where
addE k = alterKey k $ \d -> d
{ keyName = keyName d <> longext
}
longext = ".this-is-a-test-key"