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sorkisorki
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add Path hashing / parsing and tests
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‎hnix-store-core/hnix-store-core.cabal‎

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@@ -25,6 +25,7 @@ library
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, System.Nix.Nar
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, System.Nix.Path
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, System.Nix.ReadonlyStore
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, System.Nix.Internal.Path
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, System.Nix.Store
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, System.Nix.Util
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, System.Nix.ValidPath
@@ -64,6 +65,7 @@ test-suite format-tests
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other-modules:
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NarFormat
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Hash
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Path
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hs-source-dirs:
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tests
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build-depends:

‎hnix-store-core/src/System/Nix/Internal/Path.hs‎

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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE TypeApplications #-}
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{-|
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Description : Internal path utilities
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Maintainer : srk <[email protected]>
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|-}
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module System.Nix.Internal.Path where
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import Control.Monad
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import qualified Data.ByteString.Lazy as BSL
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import qualified Data.ByteString.Char8 as BSC
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import Data.Text (Text)
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import qualified Data.Text as T
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import System.FilePath.Posix (takeBaseName, takeDirectory)
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import System.Nix.Path (Path(..), PathName(..), pathName, PathHashAlgo)
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import System.Nix.Internal.Hash (Digest(..), HashAlgorithm'( SHA256 ))
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import System.Nix.Hash (HasDigest, printAsBase16, printAsBase32, printHashAlgo)
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import qualified System.Nix.Hash
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-- | Parse store location
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parseStore :: BSL.ByteString -> T.Text
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parseStore = T.pack . takeDirectory . BSC.unpack . BSL.toStrict
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-- | Parse path from string
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--
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-- in form <storeDir>/<hash>-<pathName>
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-- into (Just (Path <hash> (PathName <pathName>)))
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-- or Nothing on error
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--
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-- XXX: should check for @PathHashAlgo length
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parsePath :: BSL.ByteString -> Maybe Path
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parsePath p = case name of
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Nothing -> Nothing
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Just n -> Just $ Path digest n
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where
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base = T.pack . takeBaseName . BSC.unpack . BSL.toStrict $ p
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parts = T.breakOn "-" base
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digest = Digest . BSC.pack . T.unpack . fst $ parts
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name = pathName . T.drop 1 . snd $ parts
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-- experimental
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-- Directory of the store
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type StoreDir = Text
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type Stored a = (StoreDir, a)
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-- wrap StoreDir and Path into tuple
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makeStored :: StoreDir -> Path -> Stored Path
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makeStored sl p = (sl, p)
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type PathType = Text
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-- "text:<r1>:<r2>:...<rN>"
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-- "source"
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-- "output:<id>"
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-- <id> is the name of the output (usually, "out").
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-- store settings
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data Settings = Settings {
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storeDir :: StoreDir -- settings.nixStore
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} deriving (Eq, Show)
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-- build a store path in the following form:
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-- <storeDir>/<hash>-<pathName>
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storedToText :: Stored Path -> Text
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storedToText (storeLoc, (Path digest pName)) = T.concat
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[ storeLoc
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, "/"
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, printAsBase32 @PathHashAlgo digest
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, "-"
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, pathNameContents pName
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]
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makeStorePath :: (HasDigest a) => PathType -> PathName -> Digest a -> Settings -> Text
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makeStorePath typ pName digest settings = T.concat
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[ storeDir settings
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, "/"
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, printAsBase32 @PathHashAlgo $ pathHash typ pName digest (storeDir settings)
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, "-"
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, pathNameContents pName
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]
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makeStorePath' :: (HasDigest a) => PathType -> PathName -> Digest a -> StoreDir -> Path
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makeStorePath' typ pName digest storeLoc = snd $ makeStoredPath typ pName digest storeLoc
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-- | build Stored Path from the type of the path, path name and a digest stored at StoreDir
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-- As StoreDir is part of the path hashing process we need to take it into account
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-- when building Path(s)
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makeStoredPath :: (HasDigest a) => PathType -> PathName -> Digest a -> StoreDir -> Stored Path
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makeStoredPath typ pName digest storeLoc = makeStored storeLoc $ Path (pathHash typ pName digest storeLoc) pName
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-- build <h> string which is a truncated base32 formatted SHA256 hash of <s>
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pathHash :: (HasDigest a) => PathType -> PathName -> Digest a -> StoreDir -> Digest PathHashAlgo
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pathHash typ pName digest storeLoc = System.Nix.Hash.hash . BSC.pack . T.unpack $
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makePathDigestString typ pName digest storeLoc
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-- build <s> string which is hashed and used in makeStorePath
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-- <s> = "<pathType>:<hash_algo>:<base16_hash>:<storeDir>:<pathName>"
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-- (exposed for testing purposes only)
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makePathDigestString :: (HasDigest a) => PathType -> PathName -> Digest a -> StoreDir -> Text
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makePathDigestString typ pName digest storeLoc = T.intercalate (T.pack ":")
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[ typ
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, printHashAlgo digest
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, printAsBase16 digest
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, storeLoc
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, pathNameContents pName
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]
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-- make output path from `PathName` digest and outputId which typically is "out"
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makeOutputPath :: (HasDigest a) => PathName -> Digest a -> T.Text -> Settings -> Text
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makeOutputPath pName digest outputId settings =
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makeStorePath typ (adjustName pName) digest settings
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where
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typ = T.concat [ "output:", outputId ]
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adjustName n | outputId == "out" = n
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adjustName (PathName name) | otherwise = PathName $ T.concat [ name, T.pack "-", outputId ]
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type Recursive = Bool
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-- make fixed output path from `PathName` and Recursive option
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makeFixedOutputPath :: (HasDigest a) => PathName -> Digest a -> Recursive -> Settings -> Text
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makeFixedOutputPath pName digest True settings = -- XXX: this needs be restricted to @a == @SHA256
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makeStorePath ("source") pName digest settings
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makeFixedOutputPath pName digest recursive settings =
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makeStorePath ("output:out") pName digest' settings
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where
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rec True = "r:"
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rec False = T.empty
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digest' = System.Nix.Hash.hash @SHA256 $ BSC.pack . T.unpack . T.concat $
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[ "fixed:out:"
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, rec recursive
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, printHashAlgo digest
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, printAsBase16 digest
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, ":"
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]
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-- references should be PathSet not [T.Text]
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-- but how to turn PathSet into store paths (texts) again
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-- when we don't have PathType
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type References = [T.Text]
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makeTextPath :: (HasDigest a) => PathName -> Digest a -> References-> Settings -> Text
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makeTextPath pName digest references settings =
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makeStorePath typ pName digest settings
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where typ = T.concat $ [ "text" ] ++ (map (T.cons ':') references)
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storePathForText :: PathName -> T.Text -> References -> Settings -> Text
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storePathForText pName contents references settings =
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makeTextPath pName hashOfContents references settings
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where hashOfContents = System.Nix.Hash.hash @SHA256 (BSC.pack . T.unpack $ contents)

‎hnix-store-core/src/System/Nix/ValidPath.hs‎

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@@ -8,8 +8,7 @@ module System.Nix.ValidPath
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( ValidPath(..)
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) where
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import System.Nix.Hash (Digest(..),
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HashAlgorithm(Truncated, SHA256))
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import System.Nix.Hash (Digest(..))
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import System.Nix.Path (Path(..), PathSet)
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import qualified Data.ByteString as BS
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import qualified Data.ByteString.Char8 as BSC

‎hnix-store-core/tests/Path.hs‎

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{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE ScopedTypeVariables #-}
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{-# LANGUAGE TypeApplications #-}
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module Path where
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import Control.Monad.IO.Class (liftIO)
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import Control.Exception (bracket)
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import qualified Data.ByteString as BS
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import qualified Data.ByteString.Base64.Lazy as B64
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import qualified Data.ByteString.Lazy as BSL
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import Data.Monoid ((<>))
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import qualified Data.Text as T
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import System.Directory (removeFile)
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import System.IO.Temp (withSystemTempFile, writeSystemTempFile)
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import qualified System.IO as IO -- (hGetContents, hPutStr, openFile)
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import qualified System.Process as P
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import Test.Tasty as T
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import Test.Tasty.Hspec
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import qualified Test.Tasty.HUnit as HU
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import Test.Tasty.QuickCheck
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import Text.Read (readMaybe)
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import System.Nix.Hash
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import System.Nix.Path
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import System.Nix.Internal.Hash
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import System.Nix.Internal.Path
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import NarFormat -- TODO: Move the fixtures into a common module
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spec_path :: Spec
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spec_path = do
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describe "path operations" $ do
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it "makeStorePath hashes correctly" $
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makeStorePath "text" (PathName "lal") (hash @MD5 "Hello World") (Settings "/nix/store") `shouldBe` "/nix/store/vsfi9phi6a2hvvvihyh48jn8xh9ld5ax-lal"
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it "store path for text matches real world test scenario" $
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storePathForText (PathName "lal") ("Hello World") [] (Settings "/run/user/1000/test-nix-store-a256230bc88fe520/store") `shouldBe` "/run/user/1000/test-nix-store-a256230bc88fe520/store/3v0g8si7h0as1nqdanymv2zh2gagbl4f-lal"
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it "parses valid path" $
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parsePath "/nix/store/vsfi9phi6a2hvvvihyh48jn8xh9ld5ax-lal" `shouldBe` (Just (Path (Digest "vsfi9phi6a2hvvvihyh48jn8xh9ld5ax") (PathName "lal")))
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it "fails on invalid name" $
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parsePath "/st/hash-$%^^#" `shouldBe` Nothing
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it "parses store" $
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parseStore "/nix/store/vsfi9phi6a2hvvvihyh48jn8xh9ld5ax-lal" `shouldBe` "/nix/store"

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