diff --git a/BSD3 b/BSD3 new file mode 100644 --- /dev/null +++ b/BSD3 @@ -0,0 +1,26 @@ +Copyright (c) Ian Lynagh. +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions +are met: +1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. +2. 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. +3. The names of the author may not be used to endorse or promote + products derived from this software without specific prior written + permission. + +THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/COPYING b/COPYING new file mode 100644 --- /dev/null +++ b/COPYING @@ -0,0 +1,6 @@ + +Copyright (c) Ian Lynagh, 2004, 2007. + +This package can be used under either the GPL v2, as in ./GPL-2, or the +3-clause BSD, as in ./BSD3, license. + diff --git a/Codec/Compression/Deflate/Inflate.hs b/Codec/Compression/Deflate/Inflate.hs new file mode 100644 --- /dev/null +++ b/Codec/Compression/Deflate/Inflate.hs @@ -0,0 +1,343 @@ + +{- +Inflate implementation for Haskell + +Copyright 2004, 2007 Ian Lynagh +Licence: Your choice of GPL version 2 or 3 clause BSD. + +This module provides a Haskell implementation of the inflate function, +as described by RFC 1951. +-} + +module Codec.Compression.Deflate.Inflate (Octets, inflate) where + +import Codec.Compression.LazyStateT +import Codec.Compression.UnsafeInterleave +import Codec.Compression.Utils +-- import Control.Monad +import Control.Monad.State +-- import Data.Bits +import Data.List +import Data.IORef +-- import Data.Word +import Data.ByteString.Lazy (ByteString) +import qualified Data.ByteString.Lazy as BS +import Data.ByteString.Base (fromForeignPtr) +import Foreign + +type Octet = Word8 -- The basic inut/output type +type Octets = ByteString -- We use lazy bytestrings rather than [Word8] + -- for efficiency + +type Code = Word16 -- A generic code +type Dist = Code -- A distance code (1-32768) +type LitLen = Code -- A literal/length code (3-258) +type Length = Word8 -- Number of bits needed to identify a code + +type Table = InfM Code -- A Huffman table +type Tables = (Table, Table) -- lit/len and dist Huffman tables + +data St = St { + num_bits :: !Word8, -- number of remaining input bits + bits :: !Word, -- remaining input bits (< 8) + octets :: !Octets, -- remaining input octets + history :: !(Ptr Octet), -- last 32768 output words + loc :: !Word16, -- where in history we are + var :: !(IORef Octets) -- where to put trailing chars + } + +type InfM a = LazyStateT St IO a + +extract_InfM :: IORef Octets -> Octets -> InfM a -> IO a +extract_InfM ref os m + = do arr <- mallocArray 32768 + let init_state = St { + num_bits = 0, + bits = 0, + octets = os, + history = arr, + loc = 0, + var = ref + } + evalLazyStateT m init_state + +align_8_bits :: InfM () +align_8_bits = + do s <- get + put $ s { bits = 0, num_bits = 0 } + +-- n at most 65535 +get_octets :: Word16 -> InfM Octets +get_octets n = do s <- get + let os = octets s + n' = fromIntegral n + if BS.length os < n' + then error "get_octets: Insufficient remaining" + else case BS.splitAt n' os of + (pref, suff) -> + do put $ s { octets = suff } + return pref + +-- XXX Should we mask on return instead of on store? + +-- i at most 16 +get_w16 :: Word8 -> InfM Word16 +get_w16 0 = return 0 +get_w16 i + = do s <- get + let n = num_bits s + if i == n then + do put $ s { num_bits = 0, bits = 0 } + return $ fromIntegral $ bits s + else if i < n then + do let bs = bits s + i' = fromIntegral i + mask = (1 `shiftL` i') - 1 + put $ s { num_bits = n - i, bits = bs `shiftR` i' } + return $ fromIntegral $ (bs .&. mask) + -- XXX Could inline from here down + else do let os = octets s + bs = fromIntegral $ BS.head os + let new_bs = bs `shiftL` fromIntegral n + put $ s { num_bits = num_bits s + 8, + bits = bits s .|. new_bs, + octets = BS.tail os } + get_w16 i + +-- i at most 8 +get_w8 :: Word8 -> InfM Word8 +get_w8 i = do w <- get_w16 i + return (fromIntegral w) + +get_bit :: InfM Bool +get_bit + = do s <- get + let n = num_bits s + if n > 0 then do let bs = bits s + put $ s { num_bits = n - 1, + bits = bs `shiftR` 1 } + return $ testBit bs 0 + else do let os = octets s + bs = fromIntegral $ BS.head os + put $ s { num_bits = 7, + bits = bs `shiftR` 1, + octets = BS.tail os } + return $ testBit bs 0 + +{- +We have 2 ways to provide more output. We can either write a single +octet out or repeat a given number of bits a given distance back in the +history. +-} + +output :: Octet -> InfM () +output w = + do s <- get + let l = loc s + lift $ pokeElemOff (history s) (fromIntegral l) w + put $ s { loc = (l + 1) `mod` 32768 } + +-- len `elem` [3..258] +-- dist `elem` [1..32768] +repeat_w32s :: Word16 -> Word16 -> InfM Octets +repeat_w32s len dist = do + s <- get + let l = loc s + h = history s + start_index = fromIntegral ((l - dist) `mod` 32768) + len' = fromIntegral len + -- XXX This should be roughly a moveArray + f !0 !_ !_ = return () + f num 32768 to = f num 0 to + f num from 32768 = f num from 0 + f num from to = do peekElemOff h from >>= pokeElemOff h to + f (num - 1) (from + 1) (to + 1) + put $ s { loc = (l + len) `mod` 32768 } + lift $ f len start_index (fromIntegral l) + fp <- lift $ mallocForeignPtrArray len' + lift $ withForeignPtr fp $ \p -> + if (start_index + len') <= 32768 + then copyArray p (h `advancePtr` start_index) len' + else do let len1 = 32768 - start_index + len2 = len' - len1 + copyArray p (h `advancePtr` start_index) len1 + copyArray (p `advancePtr` len1) h len2 + return $ BS.fromChunks [fromForeignPtr fp len'] + +{- +The hardcore stuff! + +To inflate an octet stream we use inflate_blocks to do the hard work. +It in turn looks at the first 3 bits to decide whether to just output an +uncompressed segment or pass off the work to inflate_tables and +inflate_codes. +-} + +inflate :: IORef Octets -> Octets -> IO Octets +inflate ref os = extract_InfM ref os (inflate_blocks False) + +-- Bool is true if we have seen the "last" block marker +inflate_blocks :: Bool -> InfM Octets +inflate_blocks True + = do align_8_bits -- redundant as we only look at octets + s <- get + liftIO $ writeIORef (var s) (octets s) + return BS.empty +inflate_blocks False + = do w <- get_w16 3 -- XXX Could be a more efficient type + let is_last = testBit w 0 + case w `shiftR` 1 of + 0 -> + do align_8_bits + len <- get_w16 16 + nlen <- get_w16 16 + -- check nlen = 1s complement of len + unless (len + nlen == -1) + $ error "inflate_blocks: Mismatched lengths" + ws <- get_octets len + mapM_ output $ BS.unpack ws -- XXX efficiency + ws_tail <- unsafeInterleave $ inflate_blocks is_last + return (ws `myAppend` ws_tail) + 1 -> + inflate_codes is_last inflate_trees_fixed + 2 -> + do tables <- inflate_tables + inflate_codes is_last tables + 3 -> error "inflate_blocks: case 11 reserved" + _ -> error "inflate_blocks: can't happen" + +inflate_tables :: InfM Tables +inflate_tables + = do hlit <- get_w16 5 + hdist <- get_w16 5 + hclen <- get_w8 4 + let f i = do w <- get_w8 3 + return (w, i) + order = [16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15] + llc_bs <- mapM f $ genericTake (hclen + 4) order + let tab = make_table llc_bs + lit_dist_lengths <- make_lit_dist_lengths tab + (258 + hlit + hdist) + (error "inflate_tables dummy") + -- XXX Use Exactly variant? + let (lit_lengths, dist_lengths) = genericSplitAt (257 + hlit) + lit_dist_lengths + lit_table = make_table (zip lit_lengths [0..]) + dist_table = make_table (zip dist_lengths [0..]) + return (lit_table, dist_table) + +{- +make_lit_dist_lengths reads n (at most ~350) dist and length code +lengths. +-} + +make_lit_dist_lengths :: Table -> Word16 -> Length -> InfM [Length] +make_lit_dist_lengths _ n _ | n < 0 = error "make_lit_dist_lengths n < 0" +make_lit_dist_lengths _ 0 _ = return [] +make_lit_dist_lengths tab n last_thing + = do c <- tab + (ls, n', last_thing') <- meta_code n c last_thing + ws <- make_lit_dist_lengths tab n' last_thing' + return (ls ++ ws) + +meta_code :: Word16 -> Code -> Length -> InfM ([Length], Word16, Length) +meta_code n i _ | i < 16 = let i' = fromIntegral i in return ([i'], n - 1, i') +meta_code n 16 last_thing + = do w <- get_w16 2 + let l = 3 + w + return (genericReplicate l last_thing, n - l, last_thing) +meta_code n 17 _ = do w <- get_w16 3 + let l = 3 + w + return (genericReplicate l 0, n - l, 0) +meta_code n 18 _ = do w <- get_w16 7 + let l = 11 + w + return (genericReplicate l 0, n - l, 0) +meta_code _ i _ = error $ "meta_code: " ++ show i + +inflate_codes :: Bool -> Tables -> InfM Octets +inflate_codes seen_last tabs@(tab_litlen, tab_dist) + = do i <- tab_litlen; + if i == 256 + then inflate_blocks seen_last + else do pref <- if i < 256 + then do let i' = fromIntegral i + output i' + return $ BS.singleton i' + else case lookup i litlens of + Nothing -> error "do_code_litlen" + -- num_extra_bits `elem` [0..5] + Just (base, num_extra_bits) -> + do extra <- get_w16 num_extra_bits + -- l `elem` [3..258] + let l = base + extra + -- dist `elem` [1..32768] + dist <- dist_code tab_dist + repeat_w32s l dist + o <- unsafeInterleave $ inflate_codes seen_last tabs + return (pref `myAppend` o) + +litlens :: [(Code, (LitLen, Word8))] +litlens = zip [257..285] $ mk_bases 3 litlen_counts ++ [(258, 0)] + where litlen_counts = [(8,0),(4,1),(4,2),(4,3),(4,4),(4,5)] + +dist_code :: Table -> InfM Dist +dist_code tab + = do code <- tab + case lookup code dists of + Nothing -> error "dist_code" + -- num_extra_bits `elem` [0..13] + Just (base, num_extra_bits) -> do extra <- get_w16 num_extra_bits + return (base + extra) + +dists :: [(Code, (Dist, Word8))] +dists = zip [0..29] $ mk_bases 1 dist_counts + where dist_counts = (4,0):map ((,) 2) [1..13] + +mk_bases :: Word16 -> [(Int, Word16)] -> [(Word16, Word8)] +mk_bases base counts = snd $ mapAccumL next_base base incs + where next_base current bs = (current + 2^bs, (current, fromIntegral bs)) + incs = concat $ map (uncurry replicate) counts + +-- The fixed tables. + +inflate_trees_fixed :: Tables +inflate_trees_fixed = (make_table $ [(8, c) | c <- [0..143]] + ++ [(9, c) | c <- [144..255]] + ++ [(7, c) | c <- [256..279]] + ++ [(8, c) | c <- [280..287]], + make_table [(5, c) | c <- [0..29]]) + +{- +The Huffman Tree + +As the name suggests, the obvious way to store Huffman trees is in a +tree datastructure. Externally we want to view them as functions though, +so we wrap the tree with \verb!get_code! which takes a list of bits and +returns the corresponding code and the remaining bits. To make a tree +from a list of length code pairs is a simple recursive process. +-} + +data Tree = Branch Tree Tree | Leaf Code | Null + +make_table :: [(Length, Code)] -> Table +make_table lcs = case make_tree 0 $ sort $ filter ((/= 0) . fst) lcs of + (tree, []) -> get_code tree + _ -> error $ "make_table: Left-over lcs from" + +get_code :: Tree -> InfM Code +get_code (Branch zero_tree one_tree) + = do b <- get_bit + if b then get_code one_tree + else get_code zero_tree +get_code (Leaf w) = return w +get_code Null = error "get_code Null" + +make_tree :: Length -> [(Length, Code)] -> (Tree, [(Length, Code)]) +make_tree _ [] = (Null, []) +make_tree i lcs@((l, c):lcs') + | i == l = (Leaf c, lcs') + | i < l = let (zero_tree, lcs_z) = make_tree (i+1) lcs + (one_tree, lcs_o) = make_tree (i+1) lcs_z + in (Branch zero_tree one_tree, lcs_o) + | otherwise = error "make_tree: can't happen" + diff --git a/Codec/Compression/GZip/GUnZip.hs b/Codec/Compression/GZip/GUnZip.hs new file mode 100644 --- /dev/null +++ b/Codec/Compression/GZip/GUnZip.hs @@ -0,0 +1,152 @@ + +module Codec.Compression.GZip.GUnZip (gunzip) where + +import Codec.Compression.Deflate.Inflate +import Codec.Compression.LazyStateT +import Codec.Compression.UnsafeInterleave +import Codec.Compression.Utils + +import Data.Char +import Data.IORef +import System.IO +import System.IO.Unsafe + +import Control.Monad.State +import Control.Monad.Trans +import Data.Bits +import Data.Word +import Data.ByteString.Lazy (ByteString) +import qualified Data.ByteString.Lazy as BS + +type GUnZipM a = LazyStateT ByteString IO a + +readBytes :: Integral a => a -> GUnZipM ByteString +readBytes n = do xs <- get + case genericSplitAtExactlyBS n xs of + Just (ys, zs) -> + do put zs + return ys + Nothing -> failWith $ InsufficientBytes "readBytes" + +readNulTerminatedLatin1 :: GUnZipM ByteString +readNulTerminatedLatin1 + = do xs <- get + case BS.break (0 ==) xs of + (ys, zs) + | not (BS.null zs) -> + do put (BS.tail zs) + return ys + _ -> failWith $ InsufficientBytes "readNulTerminatedLatin1" + +readWord8 :: GUnZipM Word8 +readWord8 = do xs <- get + case headTail xs of + Just (x, xs') -> + do put xs' + return x + Nothing -> failWith $ InsufficientBytes "readWord8" + +readWord16 :: GUnZipM Word16 +readWord16 = do xs0 <- get + case do (x1, xs1) <- headTail xs0 + (x2, xs2) <- headTail xs1 + return (x1, x2, xs2) of + Just (x1, x2, xs') -> + do put xs' + return ( (fromIntegral x1) + + shiftL (fromIntegral x2) 8) + Nothing -> failWith $ InsufficientBytes "readWord16" + +readWord32 :: GUnZipM Word32 +readWord32 = do xs0 <- get + case do (x1, xs1) <- headTail xs0 + (x2, xs2) <- headTail xs1 + (x3, xs3) <- headTail xs2 + (x4, xs4) <- headTail xs3 + return (x1, x2, x3, x4, xs4) of + Just (x1, x2, x3, x4, xs') -> + do put xs' + return ( (fromIntegral x1) + + shiftL (fromIntegral x2) 8 + + shiftL (fromIntegral x3) 16 + + shiftL (fromIntegral x4) 24) + Nothing -> failWith $ InsufficientBytes "readWord32" + +----- + +data Error = InsufficientBytes String + | BadID1 Word8 + | BadID2 Word8 + | UnknownCompressionMethod Word8 + | ReservedFlagBitSet Int + deriving Show + +failWith :: Error -> GUnZipM a +failWith e = error ("Failure: Codec.Compression.GZip.GUnZip: " ++ show e) + +readHeader :: GUnZipM () -- XXX Should return Header? +readHeader = do id1 <- readWord8 + unless (id1 == 31) $ failWith (BadID1 id1) + id2 <- readWord8 + unless (id2 == 139) $ failWith (BadID2 id2) + cm <- readWord8 + unless (cm == 8) $ failWith (UnknownCompressionMethod cm) + flg <- readWord8 + -- We currently ignore flg bit 0 (FTEXT) + when (testBit flg 5) $ failWith (ReservedFlagBitSet 5) + when (testBit flg 6) $ failWith (ReservedFlagBitSet 6) + when (testBit flg 7) $ failWith (ReservedFlagBitSet 7) + _mtime <- readWord32 -- We ignore this for now + _xfl <- readWord8 -- We ignore this for now + _os <- readWord8 -- We ignore this for now + -- We ignore this for now + _m_fextra <- if testBit flg 2 + then do xlen <- readWord16 + extra <- readBytes xlen + return (Just extra) + else return Nothing + -- We ignore this for now + _m_fname <- if testBit flg 3 + then liftM Just readNulTerminatedLatin1 + else return Nothing + -- We ignore this for now + _m_fcomment <- if testBit flg 4 + then liftM Just readNulTerminatedLatin1 + else return Nothing + _m_hcrc <- if testBit flg 1 + then liftM Just readWord16 + else return Nothing + return () + +readFooter :: GUnZipM () -- XXX Should return Footer? +readFooter = do _crc32 <- readWord32 -- We ignore this for now + _isize <- readWord32 -- We ignore this for now + return () + +readChunks :: GUnZipM ByteString +readChunks + = do bs <- get + if BS.null bs then return BS.empty else do + readHeader + xs <- get + put BS.empty -- We don't want the monad to hold on to the + -- whole input + var <- liftIO $ newIORef (error "IORef used before initialised") + ws <- liftIO $ inflate var xs + ws' <- unsafeInterleave $ do + rest <- liftIO $ readIORef var + put rest + readFooter + readChunks + return (ws `myAppend` ws') + +gunzip :: ByteString -> ByteString +gunzip xs = unsafePerformIO $ evalLazyStateT readChunks xs + +{- +... (the compressed data) + +CRC32 (4 bytes) CRC32 of the uncompressed data +ISIZE (4 bytes) uncompressed data size mod 2^32 +-} + diff --git a/Codec/Compression/LazyStateT.hs b/Codec/Compression/LazyStateT.hs new file mode 100644 --- /dev/null +++ b/Codec/Compression/LazyStateT.hs @@ -0,0 +1,42 @@ + +module Codec.Compression.LazyStateT where + +import Control.Monad.State +import Codec.Compression.UnsafeInterleave + +data LazyStateT s m a = LazyStateT { runLazyStateT :: s -> m (a, s) } + +evalLazyStateT :: Monad m => LazyStateT s m a -> s -> m a +evalLazyStateT m s = do (x, _) <- runLazyStateT m s + return x + +execLazyStateT :: Monad m => LazyStateT s m a -> s -> m s +execLazyStateT m s = do (_, s') <- runLazyStateT m s + return s' + +instance Monad m => Monad (LazyStateT s m) where + -- (>>=) :: LazyStateT s m a -> (a -> LazyStateT s m b) -> LazyStateT s m b + LazyStateT v >>= f = LazyStateT $ \s -> do ~(x, s') <- v s + let LazyStateT y = f x + y s' + -- return :: a -> LazyStateT s m a + return x = LazyStateT $ \s -> return (x, s) + -- fail :: String -> LazyStateT s m a + fail str = LazyStateT $ \_ -> fail str + +instance MonadTrans (LazyStateT s) where + lift m = LazyStateT $ \s -> do x <- m + return (x, s) + +instance Monad m => MonadState s (LazyStateT s m) where + get = LazyStateT $ \s -> return (s, s) + put s = LazyStateT $ \_ -> return ((), s) + +instance MonadIO m => MonadIO (LazyStateT s m) where + liftIO m = LazyStateT $ \s -> do x <- liftIO m + return (x, s) + +instance UnsafeInterleave m => UnsafeInterleave (LazyStateT s m) where + unsafeInterleave (LazyStateT v) + = LazyStateT $ \s -> unsafeInterleave (v s) + diff --git a/Codec/Compression/UnsafeInterleave.hs b/Codec/Compression/UnsafeInterleave.hs new file mode 100644 --- /dev/null +++ b/Codec/Compression/UnsafeInterleave.hs @@ -0,0 +1,15 @@ + +module Codec.Compression.UnsafeInterleave where + +import Control.Monad.ST +import System.IO.Unsafe + +class UnsafeInterleave m where + unsafeInterleave :: m a -> m a + +instance UnsafeInterleave IO where + unsafeInterleave = unsafeInterleaveIO + +instance UnsafeInterleave (ST s) where + unsafeInterleave = unsafeInterleaveST + diff --git a/Codec/Compression/Utils.hs b/Codec/Compression/Utils.hs new file mode 100644 --- /dev/null +++ b/Codec/Compression/Utils.hs @@ -0,0 +1,30 @@ + +module Codec.Compression.Utils where + +import Data.ByteString.Lazy (ByteString) +import qualified Data.ByteString.Lazy as BS +import Data.ByteString.Base (LazyByteString(LPS)) +import Data.Word (Word8) + +genericSplitAtExactly :: Integral a => a -> [b] -> Maybe ([b], [b]) +genericSplitAtExactly 0 xs = return ([], xs) +genericSplitAtExactly (n+1) (x:xs) = do (ys, zs) <- genericSplitAtExactly n xs + return (x:ys, zs) +genericSplitAtExactly _ _ = Nothing + +genericSplitAtExactlyBS :: Integral a + => a -> ByteString -> Maybe (ByteString, ByteString) +genericSplitAtExactlyBS i bs = let i' = fromIntegral i + in if i' > BS.length bs + then Nothing + else Just (BS.splitAt i' bs) + +headTail :: ByteString -> Maybe (Word8, ByteString) +headTail bs = if BS.null bs + then Nothing + else Just (BS.head bs, BS.tail bs) + +-- XXX The real append is too strict +myAppend :: ByteString -> ByteString -> ByteString +myAppend (LPS xs) (LPS ys) = LPS (xs ++ ys) + diff --git a/GPL-2 b/GPL-2 new file mode 100644 --- /dev/null +++ b/GPL-2 @@ -0,0 +1,340 @@ + GNU GENERAL PUBLIC LICENSE + Version 2, June 1991 + + Copyright (C) 1989, 1991 Free Software Foundation, Inc. + 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The licenses for most software are designed to take away your +freedom to share and change it. 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But when you +distribute the same sections as part of a whole which is a work based +on the Program, the distribution of the whole must be on the terms of +this License, whose permissions for other licensees extend to the +entire whole, and thus to each and every part regardless of who wrote it. + +Thus, it is not the intent of this section to claim rights or contest +your rights to work written entirely by you; rather, the intent is to +exercise the right to control the distribution of derivative or +collective works based on the Program. + +In addition, mere aggregation of another work not based on the Program +with the Program (or with a work based on the Program) on a volume of +a storage or distribution medium does not bring the other work under +the scope of this License. + + 3. You may copy and distribute the Program (or a work based on it, +under Section 2) in object code or executable form under the terms of +Sections 1 and 2 above provided that you also do one of the following: + + a) Accompany it with the complete corresponding machine-readable + source code, which must be distributed under the terms of Sections + 1 and 2 above on a medium customarily used for software interchange; or, + + b) Accompany it with a written offer, valid for at least three + years, to give any third party, for a charge no more than your + cost of physically performing source distribution, a complete + machine-readable copy of the corresponding source code, to be + distributed under the terms of Sections 1 and 2 above on a medium + customarily used for software interchange; or, + + c) Accompany it with the information you received as to the offer + to distribute corresponding source code. (This alternative is + allowed only for noncommercial distribution and only if you + received the program in object code or executable form with such + an offer, in accord with Subsection b above.) + +The source code for a work means the preferred form of the work for +making modifications to it. For an executable work, complete source +code means all the source code for all modules it contains, plus any +associated interface definition files, plus the scripts used to +control compilation and installation of the executable. However, as a +special exception, the source code distributed need not include +anything that is normally distributed (in either source or binary +form) with the major components (compiler, kernel, and so on) of the +operating system on which the executable runs, unless that component +itself accompanies the executable. + +If distribution of executable or object code is made by offering +access to copy from a designated place, then offering equivalent +access to copy the source code from the same place counts as +distribution of the source code, even though third parties are not +compelled to copy the source along with the object code. + + 4. You may not copy, modify, sublicense, or distribute the Program +except as expressly provided under this License. Any attempt +otherwise to copy, modify, sublicense or distribute the Program is +void, and will automatically terminate your rights under this License. +However, parties who have received copies, or rights, from you under +this License will not have their licenses terminated so long as such +parties remain in full compliance. + + 5. You are not required to accept this License, since you have not +signed it. However, nothing else grants you permission to modify or +distribute the Program or its derivative works. These actions are +prohibited by law if you do not accept this License. Therefore, by +modifying or distributing the Program (or any work based on the +Program), you indicate your acceptance of this License to do so, and +all its terms and conditions for copying, distributing or modifying +the Program or works based on it. + + 6. Each time you redistribute the Program (or any work based on the +Program), the recipient automatically receives a license from the +original licensor to copy, distribute or modify the Program subject to +these terms and conditions. You may not impose any further +restrictions on the recipients' exercise of the rights granted herein. +You are not responsible for enforcing compliance by third parties to +this License. + + 7. If, as a consequence of a court judgment or allegation of patent +infringement or for any other reason (not limited to patent issues), +conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot +distribute so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you +may not distribute the Program at all. For example, if a patent +license would not permit royalty-free redistribution of the Program by +all those who receive copies directly or indirectly through you, then +the only way you could satisfy both it and this License would be to +refrain entirely from distribution of the Program. + +If any portion of this section is held invalid or unenforceable under +any particular circumstance, the balance of the section is intended to +apply and the section as a whole is intended to apply in other +circumstances. + +It is not the purpose of this section to induce you to infringe any +patents or other property right claims or to contest validity of any +such claims; this section has the sole purpose of protecting the +integrity of the free software distribution system, which is +implemented by public license practices. Many people have made +generous contributions to the wide range of software distributed +through that system in reliance on consistent application of that +system; it is up to the author/donor to decide if he or she is willing +to distribute software through any other system and a licensee cannot +impose that choice. + +This section is intended to make thoroughly clear what is believed to +be a consequence of the rest of this License. + + 8. If the distribution and/or use of the Program is restricted in +certain countries either by patents or by copyrighted interfaces, the +original copyright holder who places the Program under this License +may add an explicit geographical distribution limitation excluding +those countries, so that distribution is permitted only in or among +countries not thus excluded. In such case, this License incorporates +the limitation as if written in the body of this License. + + 9. The Free Software Foundation may publish revised and/or new versions +of the General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + +Each version is given a distinguishing version number. If the Program +specifies a version number of this License which applies to it and "any +later version", you have the option of following the terms and conditions +either of that version or of any later version published by the Free +Software Foundation. If the Program does not specify a version number of +this License, you may choose any version ever published by the Free Software +Foundation. + + 10. If you wish to incorporate parts of the Program into other free +programs whose distribution conditions are different, write to the author +to ask for permission. For software which is copyrighted by the Free +Software Foundation, write to the Free Software Foundation; we sometimes +make exceptions for this. Our decision will be guided by the two goals +of preserving the free status of all derivatives of our free software and +of promoting the sharing and reuse of software generally. + + NO WARRANTY + + 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY +FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN +OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES +PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED +OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS +TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, +REPAIR OR CORRECTION. + + 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Library General +Public License instead of this License. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,8 @@ + +module Main (main) where + +import Distribution.Simple + +main :: IO () +main = defaultMain + diff --git a/compression.cabal b/compression.cabal new file mode 100644 --- /dev/null +++ b/compression.cabal @@ -0,0 +1,30 @@ +Name: compression +Version: 0.1 +License: OtherLicense +License-File: COPYING +Copyright: Ian Lynagh, 2004, 2007 +Author: Ian Lynagh +Maintainer: igloo@earth.li +Stability: experimental +Homepage: http://urchin.earth.li/~ian/cabal/compression/ +Synopsis: Common compression algorithms. +Description: + Currently contains: + * An implementation of the inflate algorithm from RFC 1951 + (decompression only). + * An implementation of the gzip algorithm from RFC 1952 + (decompression only). +Category: Codec +Extensions: MultiParamTypeClasses, BangPatterns +Tested-With: GHC==6.6 +Build-Depends: base, mtl +Extra-source-files: "BSD3", "GPL-2" +Exposed-modules: + Codec.Compression.Deflate.Inflate + Codec.Compression.GZip.GUnZip +Other-modules: + Codec.Compression.LazyStateT + Codec.Compression.UnsafeInterleave + Codec.Compression.Utils +GHC-Options: -O -Wall +