diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,30 @@ +Redistribution and use in source and binary forms, with or +without modification, are permitted provided that the +following conditions are met: + + * Redistributions of source code must retain the above + copyright notice, this list of conditions and the + following disclaimer. + + * Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the + following disclaimer in the documentation and/or other + materials provided with the distribution. + + * The names of its contributors may not be used to endorse + or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND +CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, +INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR +CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT +NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR +OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,6 @@ +module Main ( main ) where + +import Distribution.Simple + +main :: IO () +main = defaultMain diff --git a/hackage-db.cabal b/hackage-db.cabal new file mode 100644 --- /dev/null +++ b/hackage-db.cabal @@ -0,0 +1,51 @@ +Name: hackage-db +Version: 1.0 +Copyright: Peter Simons +License: BSD3 +License-File: LICENSE +Author: Peter Simons +Maintainer: Peter Simons +Homepage: http://github.com/peti/hackage-db +Category: Distribution +Synopsis: provide access to the Hackage database via Data.Map +Cabal-Version: >= 1.8 +Build-Type: Simple +Tested-With: GHC == 6.12.3, GHC == 7.0.4, GHC == 7.2.1 +Description: + This module provides simple access to the Hackage database by means + of @Data.Map@. Suppose you wanted to implement a utility that queries + the set of available versions for a given package, the following + program would do the trick: + . + > import qualified Distribution.Hackage.DB as DB + > import Distribution.Text ( display ) + > import System.Environment ( getArgs ) + > + > main :: IO () + > main = do + > pkgs <- getArgs + > db <- DB.readHackage + > let getVersions name = maybe [] DB.keys (DB.lookup name db) + > mapM_ (putStrLn . unwords . map display . getVersions) pkgs + . + When run, it would produce the following output: + . + > ./a.out containers deepseq cabal-install + > 0.1.0.0 0.1.0.1 0.2.0.0 0.2.0.1 0.3.0.0 0.4.0.0 + > 1.0.0.0 1.1.0.0 1.1.0.1 1.1.0.2 + > 0.4.0 0.5.0 0.5.1 0.5.2 0.6.0 0.6.2 0.6.4 0.8.0 0.8.2 0.10.0 0.10.2 + . + Note that once the database has been parsed, it can be accessed + quickly, but the inital cost of reading @00-index.tar@ is fairly + high. + +Source-Repository head + Type: git + Location: git://github.com/peti/hackage-db.git + +Library + Build-Depends: base >= 3 && < 5, tar, Cabal, containers, + directory, filepath, bytestring + hs-source-dirs: src + Ghc-Options: -Wall + Exposed-Modules: Distribution.Hackage.DB diff --git a/src/Distribution/Hackage/DB.hs b/src/Distribution/Hackage/DB.hs new file mode 100644 --- /dev/null +++ b/src/Distribution/Hackage/DB.hs @@ -0,0 +1,80 @@ +{- | + Module : Distribution.Hackage.DB + License : BSD3 + + Maintainer : simons@cryp.to + Stability : provisional + Portability : portable + + This module provides simple access to the Hackage database by means + of 'Map'. Note that once the database has been parsed, it can be + accessed quickly, but the inital cost of reading @00-index.tar@ is + fairly high. + -} + +module Distribution.Hackage.DB + ( Hackage, readHackage, readHackage', parseHackage + , module Data.Map + , module Data.Version + , module Distribution.Package + , module Distribution.PackageDescription + ) + where + +import qualified Codec.Archive.Tar as Tar +import Data.ByteString.Lazy.Char8 ( ByteString ) +import qualified Data.ByteString.Lazy.Char8 as BS +import Data.Map +import Data.Maybe +import Data.Version +import System.Directory +import System.FilePath +import Distribution.Package +import Distribution.Text +import Distribution.PackageDescription +import Distribution.PackageDescription.Parse ( parsePackageDescription, ParseResult(..) ) + +-- | A 'Map' representation of the Hackage database. For sake of +-- simplicity, we use 'String' rather than 'PackageName' to represent +-- the name of a package. + +type Hackage = Map String (Map Version GenericPackageDescription) + +-- | Read the Hackage database from +-- @$HOME\/.cabal\/packages\/hackage.haskell.org\/00-index.tar@ and +-- return a 'Map' that provides fast access to its contents. That @tar@ +-- file is typically created by running the command @\"cabal update\"@. + +readHackage :: IO Hackage +readHackage = do + homedir <- getHomeDirectory + readHackage' (joinPath [ homedir, ".cabal", "packages", "hackage.haskell.org", "00-index.tar" ]) + +-- | Read the Hackage database from the given 'FilePath' and return a +-- 'Hackage' map that provides fast access to its contents. + +readHackage' :: FilePath -> IO Hackage +readHackage' = fmap parseHackage . BS.readFile + +-- | Parse the contents of Hackage's @00-index.tar@ into a 'Hackage' map. + +parseHackage :: ByteString -> Hackage +parseHackage = Tar.foldEntries addEntry empty error . Tar.read + where + addEntry :: Tar.Entry -> Hackage -> Hackage + addEntry e db = case splitDirectories (Tar.entryPath e) of + path@[name,vers,_] -> case Tar.entryContent e of + Tar.NormalFile buf _ -> add name vers buf db + _ -> error ("unexpected content of " ++ show path) + _ -> db + + add :: String -> String -> ByteString -> Hackage -> Hackage + add name version pkg = insertWith union name (singleton (pVersion version) (pPackage name pkg)) + + pPackage :: String -> ByteString -> GenericPackageDescription + pPackage name buf = case parsePackageDescription (BS.unpack buf) of + ParseOk _ a -> a + ParseFailed err -> error ("cannot parse cabal file " ++ show name ++ ": " ++ show err) + + pVersion :: String -> Version + pVersion str = fromMaybe (error $ "cannot parse version " ++ show str) (simpleParse str)