diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,373 @@ +Mozilla Public License Version 2.0 +================================== + +1. Definitions +-------------- + +1.1. "Contributor" + means each individual or legal entity that creates, contributes to + the creation of, or owns Covered Software. + +1.2. "Contributor Version" + means the combination of the Contributions of others (if any) used + by a Contributor and that particular Contributor's Contribution. + +1.3. "Contribution" + means Covered Software of a particular Contributor. + +1.4. "Covered Software" + means Source Code Form to which the initial Contributor has attached + the notice in Exhibit A, the Executable Form of such Source Code + Form, and Modifications of such Source Code Form, in each case + including portions thereof. + +1.5. "Incompatible With Secondary Licenses" + means + + (a) that the initial Contributor has attached the notice described + in Exhibit B to the Covered Software; or + + (b) that the Covered Software was made available under the terms of + version 1.1 or earlier of the License, but not also under the + terms of a Secondary License. + +1.6. "Executable Form" + means any form of the work other than Source Code Form. + +1.7. "Larger Work" + means a work that combines Covered Software with other material, in + a separate file or files, that is not Covered Software. + +1.8. "License" + means this document. + +1.9. "Licensable" + means having the right to grant, to the maximum extent possible, + whether at the time of the initial grant or subsequently, any and + all of the rights conveyed by this License. + +1.10. "Modifications" + means any of the following: + + (a) any file in Source Code Form that results from an addition to, + deletion from, or modification of the contents of Covered + Software; or + + (b) any new file in Source Code Form that contains any Covered + Software. + +1.11. "Patent Claims" of a Contributor + means any patent claim(s), including without limitation, method, + process, and apparatus claims, in any patent Licensable by such + Contributor that would be infringed, but for the grant of the + License, by the making, using, selling, offering for sale, having + made, import, or transfer of either its Contributions or its + Contributor Version. + +1.12. "Secondary License" + means either the GNU General Public License, Version 2.0, the GNU + Lesser General Public License, Version 2.1, the GNU Affero General + Public License, Version 3.0, or any later versions of those + licenses. + +1.13. "Source Code Form" + means the form of the work preferred for making modifications. + +1.14. "You" (or "Your") + means an individual or a legal entity exercising rights under this + License. For legal entities, "You" includes any entity that + controls, is controlled by, or is under common control with You. For + purposes of this definition, "control" means (a) the power, direct + or indirect, to cause the direction or management of such entity, + whether by contract or otherwise, or (b) ownership of more than + fifty percent (50%) of the outstanding shares or beneficial + ownership of such entity. + +2. License Grants and Conditions +-------------------------------- + +2.1. Grants + +Each Contributor hereby grants You a world-wide, royalty-free, +non-exclusive license: + +(a) under intellectual property rights (other than patent or trademark) + Licensable by such Contributor to use, reproduce, make available, + modify, display, perform, distribute, and otherwise exploit its + Contributions, either on an unmodified basis, with Modifications, or + as part of a Larger Work; and + +(b) under Patent Claims of such Contributor to make, use, sell, offer + for sale, have made, import, and otherwise transfer either its + Contributions or its Contributor Version. + +2.2. Effective Date + +The licenses granted in Section 2.1 with respect to any Contribution +become effective for each Contribution on the date the Contributor first +distributes such Contribution. + +2.3. Limitations on Grant Scope + +The licenses granted in this Section 2 are the only rights granted under +this License. No additional rights or licenses will be implied from the +distribution or licensing of Covered Software under this License. +Notwithstanding Section 2.1(b) above, no patent license is granted by a +Contributor: + +(a) for any code that a Contributor has removed from Covered Software; + or + +(b) for infringements caused by: (i) Your and any other third party's + modifications of Covered Software, or (ii) the combination of its + Contributions with other software (except as part of its Contributor + Version); or + +(c) under Patent Claims infringed by Covered Software in the absence of + its Contributions. + +This License does not grant any rights in the trademarks, service marks, +or logos of any Contributor (except as may be necessary to comply with +the notice requirements in Section 3.4). + +2.4. Subsequent Licenses + +No Contributor makes additional grants as a result of Your choice to +distribute the Covered Software under a subsequent version of this +License (see Section 10.2) or under the terms of a Secondary License (if +permitted under the terms of Section 3.3). + +2.5. Representation + +Each Contributor represents that the Contributor believes its +Contributions are its original creation(s) or it has sufficient rights +to grant the rights to its Contributions conveyed by this License. + +2.6. Fair Use + +This License is not intended to limit any rights You have under +applicable copyright doctrines of fair use, fair dealing, or other +equivalents. + +2.7. Conditions + +Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted +in Section 2.1. + +3. Responsibilities +------------------- + +3.1. Distribution of Source Form + +All distribution of Covered Software in Source Code Form, including any +Modifications that You create or to which You contribute, must be under +the terms of this License. You must inform recipients that the Source +Code Form of the Covered Software is governed by the terms of this +License, and how they can obtain a copy of this License. You may not +attempt to alter or restrict the recipients' rights in the Source Code +Form. + +3.2. Distribution of Executable Form + +If You distribute Covered Software in Executable Form then: + +(a) such Covered Software must also be made available in Source Code + Form, as described in Section 3.1, and You must inform recipients of + the Executable Form how they can obtain a copy of such Source Code + Form by reasonable means in a timely manner, at a charge no more + than the cost of distribution to the recipient; and + +(b) You may distribute such Executable Form under the terms of this + License, or sublicense it under different terms, provided that the + license for the Executable Form does not attempt to limit or alter + the recipients' rights in the Source Code Form under this License. + +3.3. Distribution of a Larger Work + +You may create and distribute a Larger Work under terms of Your choice, +provided that You also comply with the requirements of this License for +the Covered Software. If the Larger Work is a combination of Covered +Software with a work governed by one or more Secondary Licenses, and the +Covered Software is not Incompatible With Secondary Licenses, this +License permits You to additionally distribute such Covered Software +under the terms of such Secondary License(s), so that the recipient of +the Larger Work may, at their option, further distribute the Covered +Software under the terms of either this License or such Secondary +License(s). + +3.4. Notices + +You may not remove or alter the substance of any license notices +(including copyright notices, patent notices, disclaimers of warranty, +or limitations of liability) contained within the Source Code Form of +the Covered Software, except that You may alter any license notices to +the extent required to remedy known factual inaccuracies. + +3.5. Application of Additional Terms + +You may choose to offer, and to charge a fee for, warranty, support, +indemnity or liability obligations to one or more recipients of Covered +Software. However, You may do so only on Your own behalf, and not on +behalf of any Contributor. You must make it absolutely clear that any +such warranty, support, indemnity, or liability obligation is offered by +You alone, and You hereby agree to indemnify every Contributor for any +liability incurred by such Contributor as a result of warranty, support, +indemnity or liability terms You offer. You may include additional +disclaimers of warranty and limitations of liability specific to any +jurisdiction. + +4. Inability to Comply Due to Statute or Regulation +--------------------------------------------------- + +If it is impossible for You to comply with any of the terms of this +License with respect to some or all of the Covered Software due to +statute, judicial order, or regulation then You must: (a) comply with +the terms of this License to the maximum extent possible; and (b) +describe the limitations and the code they affect. Such description must +be placed in a text file included with all distributions of the Covered +Software under this License. Except to the extent prohibited by statute +or regulation, such description must be sufficiently detailed for a +recipient of ordinary skill to be able to understand it. + +5. Termination +-------------- + +5.1. The rights granted under this License will terminate automatically +if You fail to comply with any of its terms. However, if You become +compliant, then the rights granted under this License from a particular +Contributor are reinstated (a) provisionally, unless and until such +Contributor explicitly and finally terminates Your grants, and (b) on an +ongoing basis, if such Contributor fails to notify You of the +non-compliance by some reasonable means prior to 60 days after You have +come back into compliance. Moreover, Your grants from a particular +Contributor are reinstated on an ongoing basis if such Contributor +notifies You of the non-compliance by some reasonable means, this is the +first time You have received notice of non-compliance with this License +from such Contributor, and You become compliant prior to 30 days after +Your receipt of the notice. + +5.2. If You initiate litigation against any entity by asserting a patent +infringement claim (excluding declaratory judgment actions, +counter-claims, and cross-claims) alleging that a Contributor Version +directly or indirectly infringes any patent, then the rights granted to +You by any and all Contributors for the Covered Software under Section +2.1 of this License shall terminate. + +5.3. In the event of termination under Sections 5.1 or 5.2 above, all +end user license agreements (excluding distributors and resellers) which +have been validly granted by You or Your distributors under this License +prior to termination shall survive termination. + +************************************************************************ +* * +* 6. Disclaimer of Warranty * +* ------------------------- * +* * +* Covered Software is provided under this License on an "as is" * +* basis, without warranty of any kind, either expressed, implied, or * +* statutory, including, without limitation, warranties that the * +* Covered Software is free of defects, merchantable, fit for a * +* particular purpose or non-infringing. The entire risk as to the * +* quality and performance of the Covered Software is with You. * +* Should any Covered Software prove defective in any respect, You * +* (not any Contributor) assume the cost of any necessary servicing, * +* repair, or correction. This disclaimer of warranty constitutes an * +* essential part of this License. No use of any Covered Software is * +* authorized under this License except under this disclaimer. * +* * +************************************************************************ + +************************************************************************ +* * +* 7. Limitation of Liability * +* -------------------------- * +* * +* Under no circumstances and under no legal theory, whether tort * +* (including negligence), contract, or otherwise, shall any * +* Contributor, or anyone who distributes Covered Software as * +* permitted above, be liable to You for any direct, indirect, * +* special, incidental, or consequential damages of any character * +* including, without limitation, damages for lost profits, loss of * +* goodwill, work stoppage, computer failure or malfunction, or any * +* and all other commercial damages or losses, even if such party * +* shall have been informed of the possibility of such damages. This * +* limitation of liability shall not apply to liability for death or * +* personal injury resulting from such party's negligence to the * +* extent applicable law prohibits such limitation. Some * +* jurisdictions do not allow the exclusion or limitation of * +* incidental or consequential damages, so this exclusion and * +* limitation may not apply to You. * +* * +************************************************************************ + +8. Litigation +------------- + +Any litigation relating to this License may be brought only in the +courts of a jurisdiction where the defendant maintains its principal +place of business and such litigation shall be governed by laws of that +jurisdiction, without reference to its conflict-of-law provisions. +Nothing in this Section shall prevent a party's ability to bring +cross-claims or counter-claims. + +9. Miscellaneous +---------------- + +This License represents the complete agreement concerning the subject +matter hereof. If any provision of this License is held to be +unenforceable, such provision shall be reformed only to the extent +necessary to make it enforceable. Any law or regulation which provides +that the language of a contract shall be construed against the drafter +shall not be used to construe this License against a Contributor. + +10. Versions of the License +--------------------------- + +10.1. New Versions + +Mozilla Foundation is the license steward. Except as provided in Section +10.3, no one other than the license steward has the right to modify or +publish new versions of this License. Each version will be given a +distinguishing version number. + +10.2. Effect of New Versions + +You may distribute the Covered Software under the terms of the version +of the License under which You originally received the Covered Software, +or under the terms of any subsequent version published by the license +steward. + +10.3. Modified Versions + +If you create software not governed by this License, and you want to +create a new license for such software, you may create and use a +modified version of this License if you rename the license and remove +any references to the name of the license steward (except to note that +such modified license differs from this License). + +10.4. Distributing Source Code Form that is Incompatible With Secondary +Licenses + +If You choose to distribute Source Code Form that is Incompatible With +Secondary Licenses under the terms of this version of the License, the +notice described in Exhibit B of this License must be attached. + +Exhibit A - Source Code Form License Notice +------------------------------------------- + + This Source Code Form is subject to the terms of the Mozilla Public + License, v. 2.0. If a copy of the MPL was not distributed with this + file, You can obtain one at http://mozilla.org/MPL/2.0/. + +If it is not possible or desirable to put the notice in a particular +file, then You may include the notice in a location (such as a LICENSE +file in a relevant directory) where a recipient would be likely to look +for such a notice. + +You may add additional accurate notices of copyright ownership. + +Exhibit B - "Incompatible With Secondary Licenses" Notice +--------------------------------------------------------- + + This Source Code Form is "Incompatible With Secondary Licenses", as + defined by the Mozilla Public License, v. 2.0. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,25 @@ +# Snappy Framing Format + +[![Build Status](https://secure.travis-ci.org/kim/snappy-framing.png)](http://travis-ci.org/kim/snappy-framing) + +Implementation of the [Snappy framing format](http://code.google.com/p/snappy/source/browse/trunk/framing_format.txt?r=71), +SVN rev 71. + +## Build, Install, Use + +Build from source using `cabal install`, from Hackage using `cabal install +snappy-framing`. + +The library exports a single module, `Codec.Compression.Snappy.Framing`, with a +instance of `Data.Binary` doing all the work. A couple of convenience functions +are also provided, but for serious stream processing use of a streaming library +of your liking (eg. pipes, iteratees, conduit) is recommended. + +## Bugs and Contributing + +Please report issues via [Github Issues](https://github.com/kim/snappy-framing/issues), +patches are welcome as [Pull Requests](https://github.com/kim/snappy-framing/pulls). + +## License + +Mozilla Public License Version 2.0, see LICENSE file. diff --git a/Setup.hs b/Setup.hs new file mode 100644 --- /dev/null +++ b/Setup.hs @@ -0,0 +1,2 @@ +import Distribution.Simple +main = defaultMain diff --git a/snappy-framing.cabal b/snappy-framing.cabal new file mode 100644 --- /dev/null +++ b/snappy-framing.cabal @@ -0,0 +1,41 @@ +name: snappy-framing +version: 0.1.0 +synopsis: Snappy Framing Format in Haskell +homepage: https://github.com/kim/snappy-framing +license: OtherLicense +license-file: LICENSE +author: Kim Altintop +maintainer: kim.altintop@gmail.com +copyright: Copyright (c) 2013 Kim Altintop +category: Codec +build-type: Simple +cabal-version: >=1.10 + +description: + Implementation of the Snappy framing format (SVN revision 71, cf. + ) + +extra-source-files: README.md + +source-repository head + type: git + location: git://github.com/kim/snappy-framing.git + +library + default-language: Haskell2010 + + hs-source-dirs: src + + ghc-options: -Wall -fwarn-tabs -funbox-strict-fields + ghc-prof-options: -prof -auto-all + + exposed-modules: Codec.Compression.Snappy.Framing + + other-modules: Data.Digest.CRC32C + + build-depends: + array >= 0.4 + , base > 4 && < 5 + , binary >= 0.7 + , bytestring >= 0.10 + , snappy >= 0.2.0.2 diff --git a/src/Codec/Compression/Snappy/Framing.hs b/src/Codec/Compression/Snappy/Framing.hs new file mode 100644 --- /dev/null +++ b/src/Codec/Compression/Snappy/Framing.hs @@ -0,0 +1,256 @@ +{-# LANGUAGE OverloadedStrings #-} + +-- | +-- Module : Codec.Compression.Snappy.Framing +-- Copyright : (c) 2013 Kim Altintop +-- License : This Source Code Form is subject to the terms of +-- the Mozilla Public License, v. 2.0. +-- A copy of the MPL can be found in the LICENSE file or +-- you can obtain it at http://mozilla.org/MPL/2.0/. +-- Maintainer : Kim Altintop +-- Stability : experimental +-- Portability : non-portable (GHC extensions) +-- + +module Codec.Compression.Snappy.Framing + ( -- * Exported Types + Checksum + , Chunk (..) + , DecodeError + + -- * Encoding and Decoding + , encode + , encode' + , decode + , decode' + , decodeVerify + , decodeVerify' + , decodeM + , decodeVerifyM + + -- * Utility functions + , checksum + , streamIdentifier + , verify + ) where + +import Control.Applicative +import Data.ByteString (ByteString) +import Data.Binary (Binary(..)) +import Data.Binary.Get +import Data.Binary.Put +import Data.Bits +import Data.Digest.CRC32C +import Data.Word + +import qualified Data.Binary as Binary +import qualified Data.ByteString as B +import qualified Data.ByteString.Lazy as BL +import qualified Codec.Compression.Snappy as Snappy + + +type Checksum = Word32 + +type DecodeError = (ByteOffset, String) + +data Chunk = StreamIdentifier + | Compressed !Checksum !ByteString + | Uncompressed !Checksum !ByteString + | Skippable !Word8 + | Unskippable !Word8 + deriving (Eq, Show) + + +streamStart :: [Word8] +streamStart = [0xff, 0x06, 0x00, 0x00, 0x73, 0x4e, 0x61, 0x50, 0x70, 0x59] + +maxUncompressed :: Int +maxUncompressed = 65536 + +minCompressible :: Int +minCompressible = 18 + +instance Binary Chunk where + put StreamIdentifier = mapM_ put streamStart + put (Compressed chk dat) = putWord8 0x00 >> putData chk dat + put (Uncompressed chk dat) = putWord8 0x01 >> putData chk dat + put (Skippable x) = put x + put (Unskippable x) = put x + + get = do + chunktype <- getWord8 + case chunktype of + 0xff -> skip (length streamStart - 1) >> return StreamIdentifier + 0x00 -> return . uncurry Compressed =<< getData + 0x01 -> return . uncurry Uncompressed =<< getData + x | x >= 0x02 && x <= 0x7f -> return $ Unskippable x + | x >= 0x80 && x <= 0xfe -> return $ Skippable x + | otherwise -> error "junk chunk type" + +getData :: Get (Checksum, ByteString) +getData = do + len <- getWord24le + chk <- getWord32le + dat <- getByteString . fromIntegral $ len - 4 + return (chk, dat) + +putData :: Checksum -> ByteString -> Put +putData chk dat = do + putWord24le (B.length dat + 4) + putWord32le chk + putByteString dat + +getWord24le :: Get Word32 +getWord24le = do + (a,b,c) <- (,,) <$> getWord8 <*> getWord8 <*> getWord8 + return $ (fromIntegral a :: Word32) + .|. (fromIntegral b :: Word32) `shiftL` 8 + .|. (fromIntegral c :: Word32) `shiftL` 16 + +putWord24le :: Int -> Put +putWord24le x = mapM_ putWord8 bytes + where + bytes = [ fromIntegral ((fromIntegral x :: Word32) `shiftR` 0) :: Word8 + , fromIntegral ((fromIntegral x :: Word32) `shiftR` 8) :: Word8 + , fromIntegral ((fromIntegral x :: Word32) `shiftR` 16) :: Word8 + ] + +-- | Compute a masked CRC32C checksum of the input +checksum :: ByteString -> Checksum +checksum a = + let chksum = crc32c a + masked = ((chksum `shiftR` 15) .|. (chksum `shiftL` 17)) + 0xa282ead8 + in masked + +-- | Verify a 'Chunk' +-- +-- Returns 'Nothing' if the input is an 'Unskippable' chunk, or the checksum +-- verification fails (if the input is a 'Compressed' or 'Uncompressed' chunk). +-- Otherwise, the input 'Chunk' is returned in a 'Just'. Note that 'Compressed' +-- chunks are decompressed into 'Uncompressed' chunks on the fly. +verify :: Chunk -> Maybe Chunk +verify u@(Uncompressed chk d) = if chk == checksum d then Just u else Nothing +verify (Compressed chk d) = if ok then Just (Uncompressed chk d') else Nothing + where + d' = Snappy.decompress d + ok = chk == checksum d' +verify (Unskippable _) = Nothing +verify c = Just c + +-- | Yield a stream identifier (start-of-stream marker) +streamIdentifier :: BL.ByteString +streamIdentifier = Binary.encode StreamIdentifier + +-- | Encode a lazy 'BL.ByteString' into a 'Chunk' +-- +-- If the input is longer than 'minCompressible' bytes, the resulting chunk is +-- 'Compressed' otherwise 'Uncompressed'. If the input size exceeds +-- 'maxUncompressed' bytes, the leftover input is returned in a 'Just'. +encode :: BL.ByteString -> (Chunk, Maybe BL.ByteString) +encode = go . split + where + go (x,xs) = (chunk $ BL.toStrict x, leftover' xs) + + chunk c + | shouldCompress c = Compressed (checksum c) (Snappy.compress c) + | otherwise = Uncompressed (checksum c) c + + split = BL.splitAt (fromIntegral maxUncompressed) + + leftover' x + | BL.null x = Nothing + | otherwise = Just x + +-- | Encode a strict 'ByteString' into a 'Chunk' +-- +-- If the input is longer than 'minCompressible' bytes, the resulting chunk is +-- 'Compressed' otherwise 'Uncompressed'. If the input size exceeds +-- 'maxUncompressed' bytes, the leftover input is returned in a 'Just'. +encode' :: ByteString -> (Chunk, Maybe ByteString) +encode' = go . split + where + go (x,xs) = (chunk x, leftover xs) + + chunk c + | shouldCompress c = Compressed (checksum c) (Snappy.compress c) + | otherwise = Uncompressed (checksum c) c + + split = B.splitAt maxUncompressed + + +-- | Decode a lazy 'BL.ByteString' into a 'Chunk' +decode :: BL.ByteString -> (Either DecodeError Chunk, Maybe ByteString) +decode = dec . feed + +-- | Decode a lazy 'BL.ByteString' into a 'Chunk' and 'verify' the result +decodeVerify :: BL.ByteString -> (Either DecodeError Chunk, Maybe ByteString) +decodeVerify = decV . feed + +-- | Decode a strict 'ByteString' into a 'Chunk' +decode' :: ByteString -> (Either DecodeError Chunk, Maybe ByteString) +decode' = dec . feed' + +-- | Decode a strict 'ByteString' into a 'Chunk' and 'verify' the result +decodeVerify' :: ByteString -> (Either DecodeError Chunk, Maybe ByteString) +decodeVerify' = decV . feed' + +-- | Decode drawing input from the given monadic action as needed +decodeM :: Monad m + => m (Maybe ByteString) + -- ^ And action that will be run to provide input. If it returns + -- 'Nothing' it is assumed no more input is available. + -> m (Either DecodeError Chunk, Maybe ByteString) + -- ^ Either a parse error or a 'Chunk', along with leftovers if any. +decodeM pull = go (runGetIncremental (get :: Get Chunk)) + where + go (Partial k) = go . k =<< pull + go (Fail r n m) = return (Left (n, m), leftover r) + go (Done r _ c) = return (Right c, leftover r) + +-- | Like 'decodeM', but 'verify' the result +decodeVerifyM :: Monad m + => m (Maybe ByteString) + -> m (Either DecodeError Chunk, Maybe ByteString) +decodeVerifyM pull = go (runGetIncremental (get :: Get Chunk)) + where + go (Partial k) = go . k =<< pull + go (Fail r n m) = return (Left (n, m), leftover r) + go (Done r n c) = case verify c of + Just c' -> return (Right c', leftover r) + Nothing -> go (Fail r n "verification failure") + +-- +-- Internal +-- + +shouldCompress :: ByteString -> Bool +shouldCompress x = B.length x >= minCompressible +{-# INLINEABLE shouldCompress #-} + +feed :: BL.ByteString -> Decoder Chunk +feed = pushChunks $ runGetIncremental get +{-# INLINEABLE feed #-} + +feed' :: ByteString -> Decoder Chunk +feed' = pushChunk $ runGetIncremental get +{-# INLINEABLE feed' #-} + +dec :: Decoder Chunk -> (Either DecodeError Chunk, Maybe ByteString) +dec (Partial k) = dec (k Nothing) +dec (Fail r n m) = (Left (n, m), leftover r) +dec (Done r _ c) = (Right c, leftover r) +{-# INLINEABLE dec #-} + +decV :: Decoder Chunk -> (Either DecodeError Chunk, Maybe ByteString) +decV (Partial k) = decV (k Nothing) +decV (Fail r n m) = (Left (n, m), leftover r) +decV (Done r n c) = case verify c of + Just c' -> (Right c', leftover r) + Nothing -> decV (Fail r n "verification failure") +{-# INLINEABLE decV #-} + +leftover :: ByteString -> Maybe ByteString +leftover x + | B.null x = Nothing + | otherwise = Just x +{-# INLINEABLE leftover #-} diff --git a/src/Data/Digest/CRC32C.hs b/src/Data/Digest/CRC32C.hs new file mode 100644 --- /dev/null +++ b/src/Data/Digest/CRC32C.hs @@ -0,0 +1,100 @@ +module Data.Digest.CRC32C + ( crc32c + , crc32c_update + ) where + +import Data.Bits +import Data.ByteString (ByteString) +import Data.Word +import Data.Array.Base (unsafeAt) +import Data.Array.Unboxed + +import qualified Data.ByteString as B + + +crc32c :: ByteString -> Word32 +crc32c = crc32c_update 0 + +crc32c_update :: Word32 -> ByteString -> Word32 +crc32c_update crc bs = flipd $ step (flipd crc) bs + where + flipd = xor 0xffffffff + +step :: Word32 -> ByteString -> Word32 +step crc bs = B.foldl step' crc bs + where + step' acc b = let x = table !!! ((acc .&. 0xff) `xor` fromIntegral b) + in x `xor` (acc `shiftR` 8) +{-# INLINEABLE step #-} + +(!!!) :: (IArray a e, Ix i, Integral i) => a i e -> i -> e +arr !!! i = unsafeAt arr $ fromIntegral i +{-# INLINEABLE (!!!) #-} + +table :: UArray Word32 Word32 +table = listArray (0,255) $ + [ 0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4 + , 0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb + , 0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b + , 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24 + , 0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b + , 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384 + , 0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54 + , 0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b + , 0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a + , 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35 + , 0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5 + , 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa + , 0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45 + , 0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a + , 0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a + , 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595 + , 0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48 + , 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957 + , 0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687 + , 0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198 + , 0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927 + , 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38 + , 0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8 + , 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7 + , 0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096 + , 0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789 + , 0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859 + , 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46 + , 0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9 + , 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6 + , 0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36 + , 0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829 + , 0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c + , 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93 + , 0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043 + , 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c + , 0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3 + , 0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc + , 0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c + , 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033 + , 0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652 + , 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d + , 0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d + , 0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982 + , 0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d + , 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622 + , 0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2 + , 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed + , 0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530 + , 0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f + , 0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff + , 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0 + , 0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f + , 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540 + , 0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90 + , 0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f + , 0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee + , 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1 + , 0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321 + , 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e + , 0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81 + , 0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e + , 0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e + , 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351 + ]