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-----------------------------------------------------------------------------
-- |
-- Module : Distribution.Client.Index
-- Maintainer : cabal-devel@haskell.org
-- Portability : portable
--
-- Querying and modifying local build tree references in the package index.
-----------------------------------------------------------------------------
module Distribution.Client.Index (
index,
createEmpty,
addBuildTreeRefs,
removeBuildTreeRefs,
listBuildTreeRefs,
defaultIndexFileName
) where
import qualified Distribution.Client.Tar as Tar
import Distribution.Client.IndexUtils ( getSourcePackages )
import Distribution.Client.PackageIndex ( allPackages )
import Distribution.Client.Setup ( IndexFlags(..) )
import Distribution.Client.Types ( Repo(..), LocalRepo(..)
, SourcePackageDb(..)
, SourcePackage(..), PackageLocation(..) )
import Distribution.Client.Utils ( byteStringToFilePath, filePathToByteString
, makeAbsoluteToCwd )
import Distribution.Simple.Setup ( fromFlagOrDefault )
import Distribution.Simple.Utils ( die, debug, notice, findPackageDesc )
import Distribution.Verbosity ( Verbosity )
import qualified Data.ByteString.Lazy as BS
import Control.Exception ( evaluate )
import Control.Monad ( liftM, when, unless )
import Data.List ( (\\), nub )
import Data.Maybe ( catMaybes )
import System.Directory ( canonicalizePath, createDirectoryIfMissing,
doesDirectoryExist, doesFileExist,
renameFile )
import System.FilePath ( (</>), (<.>), takeDirectory, takeExtension )
import System.IO ( IOMode(..), SeekMode(..)
, hSeek, withBinaryFile )
-- | A reference to a local build tree.
newtype BuildTreeRef = BuildTreeRef {
buildTreePath :: FilePath
}
defaultIndexFileName :: FilePath
defaultIndexFileName = "00-index.tar"
-- | Entry point for the 'cabal index' command.
index :: Verbosity -> IndexFlags -> FilePath -> IO ()
index verbosity indexFlags path' = do
let runInit = fromFlagOrDefault False (indexInit indexFlags)
let refsToAdd = indexLinkSource indexFlags
let runLinkSource = not . null $ refsToAdd
let refsToRemove = indexRemoveSource indexFlags
let runRemoveSource = not . null $ refsToRemove
let runList = fromFlagOrDefault False (indexList indexFlags)
unless (or [runInit, runLinkSource, runRemoveSource, runList]) $ do
die "no arguments passed to the 'index' command"
path <- validateIndexPath path'
when runInit $ do
createEmpty verbosity path
when runLinkSource $ do
addBuildTreeRefs verbosity path refsToAdd
when runRemoveSource $ do
removeBuildTreeRefs verbosity path refsToRemove
when runList $ do
refs <- listBuildTreeRefs verbosity path
mapM_ putStrLn refs
-- | Given a path, ensure that it refers to a local build tree.
buildTreeRefFromPath :: FilePath -> IO (Maybe BuildTreeRef)
buildTreeRefFromPath dir = do
dirExists <- doesDirectoryExist dir
when (not dirExists) $ do
die $ "directory '" ++ dir ++ "' does not exist"
_ <- findPackageDesc dir
return . Just $ BuildTreeRef { buildTreePath = dir }
-- | Given a tar archive entry, try to parse it as a local build tree reference.
readBuildTreePath :: Tar.Entry -> Maybe FilePath
readBuildTreePath entry = case Tar.entryContent entry of
(Tar.OtherEntryType typeCode bs size)
| (typeCode == Tar.buildTreeRefTypeCode)
&& (size == BS.length bs) -> Just $ byteStringToFilePath bs
| otherwise -> Nothing
_ -> Nothing
-- | Given a sequence of tar archive entries, extract all references to local
-- build trees.
readBuildTreePaths :: Tar.Entries -> [FilePath]
readBuildTreePaths =
catMaybes
. Tar.foldrEntries (\e r -> (readBuildTreePath e):r)
[] error
-- | Given a path to a tar archive, extract all references to local build trees.
readBuildTreePathsFromFile :: FilePath -> IO [FilePath]
readBuildTreePathsFromFile = liftM (readBuildTreePaths . Tar.read)
. BS.readFile
-- | Given a local build tree, serialise it to a tar archive entry.
writeBuildTreeRef :: BuildTreeRef -> Tar.Entry
writeBuildTreeRef lbt = Tar.simpleEntry tarPath content
where
bs = filePathToByteString path
path = buildTreePath lbt
-- fromRight can't fail because the path is shorter than 255 characters.
tarPath = fromRight $ Tar.toTarPath True tarPath'
-- Provide a filename for tools that treat custom entries as ordinary files.
tarPath' = "local-build-tree-reference"
content = Tar.OtherEntryType Tar.buildTreeRefTypeCode bs (BS.length bs)
-- TODO: Move this to D.C.Utils?
fromRight (Left err) = error err
fromRight (Right a) = a
-- | Check that the provided path is either an existing directory, or a tar
-- archive in an existing directory.
validateIndexPath :: FilePath -> IO FilePath
validateIndexPath path' = do
path <- makeAbsoluteToCwd path'
if (== ".tar") . takeExtension $ path
then return path
else do dirExists <- doesDirectoryExist path
unless dirExists $ do
die $ "directory does not exist: '" ++ path ++ "'"
return $ path </> defaultIndexFileName
-- | Create an empty index file.
createEmpty :: Verbosity -> FilePath -> IO ()
createEmpty verbosity path = do
indexExists <- doesFileExist path
if indexExists
then debug verbosity $ "Package index already exists: " ++ path
else do
debug verbosity $ "Creating the index file '" ++ path ++ "'"
createDirectoryIfMissing True (takeDirectory path)
-- Equivalent to 'tar cvf empty.tar --files-from /dev/null'.
let zeros = BS.replicate (512*20) 0
BS.writeFile path zeros
-- | Add given local build tree references to the index.
addBuildTreeRefs :: Verbosity -> FilePath -> [FilePath] -> IO ()
addBuildTreeRefs _ _ [] =
error "Distribution.Client.Index.addBuildTreeRefs: unexpected"
addBuildTreeRefs verbosity path l' = do
checkIndexExists path
l <- liftM nub . mapM canonicalizePath $ l'
treesInIndex <- readBuildTreePathsFromFile path
-- Add only those paths that aren't already in the index.
treesToAdd <- mapM buildTreeRefFromPath (l \\ treesInIndex)
let entries = map writeBuildTreeRef (catMaybes treesToAdd)
when (not . null $ entries) $ do
offset <-
fmap (Tar.foldrEntries (\e acc -> Tar.entrySizeInBytes e + acc) 0 error
. Tar.read) $ BS.readFile path
_ <- evaluate offset
debug verbosity $ "Writing at offset: " ++ show offset
withBinaryFile path ReadWriteMode $ \h -> do
hSeek h AbsoluteSeek (fromIntegral offset)
BS.hPut h (Tar.write entries)
debug verbosity $ "Successfully appended to '" ++ path ++ "'"
-- | Remove given local build tree references from the index.
removeBuildTreeRefs :: Verbosity -> FilePath -> [FilePath] -> IO ()
removeBuildTreeRefs _ _ [] =
error "Distribution.Client.Index.removeBuildTreeRefs: unexpected"
removeBuildTreeRefs verbosity path l' = do
checkIndexExists path
l <- mapM canonicalizePath l'
let tmpFile = path <.> "tmp"
-- Performance note: on my system, it takes 'index --remove-source'
-- approx. 3,5s to filter a 65M file. Real-life indices are expected to be
-- much smaller.
BS.writeFile tmpFile . Tar.writeEntries . Tar.filterEntries (p l) . Tar.read
=<< BS.readFile path
-- This invalidates the cache, so we don't have to update it explicitly.
renameFile tmpFile path
debug verbosity $ "Successfully renamed '" ++ tmpFile
++ "' to '" ++ path ++ "'"
where
p l entry = case readBuildTreePath entry of
Nothing -> True
(Just pth) -> not $ any (== pth) l
-- | List the local build trees that are referred to from the index.
listBuildTreeRefs :: Verbosity -> FilePath -> IO [FilePath]
listBuildTreeRefs verbosity path = do
checkIndexExists path
let repo = Repo { repoKind = Right LocalRepo
, repoLocalDir = takeDirectory path }
pkgIndex <- fmap packageIndex . getSourcePackages verbosity $ [repo]
let buildTreeRefs = [ pkgPath | (LocalUnpackedPackage pkgPath) <-
map packageSource . allPackages $ pkgIndex ]
when (null buildTreeRefs) $ do
notice verbosity $ "Index file '" ++ path
++ "' has no references to local build trees."
return buildTreeRefs
-- | Check that the package index file exists and exit with error if it does not.
checkIndexExists :: FilePath -> IO ()
checkIndexExists path = do
indexExists <- doesFileExist path
when (not indexExists) $ do
die $ "index does not exist: '" ++ path ++ "'"
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