bytestring-builder-varword (empty) → 0.1.0.0
raw patch · 8 files changed
+397/−0 lines, 8 filesdep +QuickCheckdep +attoparsecdep +attoparsec-varwordsetup-changed
Dependencies added: QuickCheck, attoparsec, attoparsec-varword, base, bytestring, bytestring-builder-varword, hspec
Files
- LICENSE +165/−0
- README.md +5/−0
- Setup.hs +2/−0
- bytestring-builder-varword.cabal +50/−0
- src/Data/ByteString/Builder/Prim/VarWord.hs +71/−0
- src/Data/ByteString/Builder/VarWord.hs +77/−0
- test/Data/ByteString/Builder/VarWordSpec.hs +26/−0
- test/Spec.hs +1/−0
+ LICENSE view
@@ -0,0 +1,165 @@+ GNU LESSER GENERAL PUBLIC LICENSE+ Version 3, 29 June 2007++ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>+ Everyone is permitted to copy and distribute verbatim copies+ of this license document, but changing it is not allowed.+++ This version of the GNU Lesser General Public License incorporates+the terms and conditions of version 3 of the GNU General Public+License, supplemented by the additional permissions listed below.++ 0. Additional Definitions.++ As used herein, "this License" refers to version 3 of the GNU Lesser+General Public License, and the "GNU GPL" refers to version 3 of the GNU+General Public License.++ "The Library" refers to a covered work governed by this License,+other than an Application or a Combined Work as defined below.++ An "Application" is any work that makes use of an interface provided+by the Library, but which is not otherwise based on the Library.+Defining a subclass of a class defined by the Library is deemed a mode+of using an interface provided by the Library.++ A "Combined Work" is a work produced by combining or linking an+Application with the Library. The particular version of the Library+with which the Combined Work was made is also called the "Linked+Version".++ The "Minimal Corresponding Source" for a Combined Work means the+Corresponding Source for the Combined Work, excluding any source code+for portions of the Combined Work that, considered in isolation, are+based on the Application, and not on the Linked Version.++ The "Corresponding Application Code" for a Combined Work means the+object code and/or source code for the Application, including any data+and utility programs needed for reproducing the Combined Work from the+Application, but excluding the System Libraries of the Combined Work.++ 1. Exception to Section 3 of the GNU GPL.++ You may convey a covered work under sections 3 and 4 of this License+without being bound by section 3 of the GNU GPL.++ 2. 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Combined Libraries.++ You may place library facilities that are a work based on the+Library side by side in a single library together with other library+facilities that are not Applications and are not covered by this+License, and convey such a combined library under terms of your+choice, if you do both of the following:++ a) Accompany the combined library with a copy of the same work based+ on the Library, uncombined with any other library facilities,+ conveyed under the terms of this License.++ b) Give prominent notice with the combined library that part of it+ is a work based on the Library, and explaining where to find the+ accompanying uncombined form of the same work.++ 6. Revised Versions of the GNU Lesser General Public License.++ The Free Software Foundation may publish revised and/or new versions+of the GNU Lesser 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+Library as you received it specifies that a certain numbered version+of the GNU Lesser General Public License "or any later version"+applies to it, you have the option of following the terms and+conditions either of that published version or of any later version+published by the Free Software Foundation. If the Library as you+received it does not specify a version number of the GNU Lesser+General Public License, you may choose any version of the GNU Lesser+General Public License ever published by the Free Software Foundation.++ If the Library as you received it specifies that a proxy can decide+whether future versions of the GNU Lesser General Public License shall+apply, that proxy's public statement of acceptance of any version is+permanent authorization for you to choose that version for the+Library.
+ README.md view
@@ -0,0 +1,5 @@+Variable-length integer encoding+================================++This package provides a collection of functions to encode integers in several+variable-length formats via `ByteString` `Builder`s.
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ bytestring-builder-varword.cabal view
@@ -0,0 +1,50 @@+name: bytestring-builder-varword+version: 0.1.0.0+synopsis: Variable-length integer encoding+description:+ A collection of functions for producing 'Data.ByteString.Builder.Builder's+ that encode integer types into compact, variable-length representations.+homepage: https://github.com/concert/hs-varword#readme+bug-reports: https://github.com/concert/hs-varword/issues+stability: Experimental+license: LGPL-3+license-file: LICENSE+author: Paul Weaver+maintainer: paul@concertdaw.co.uk+copyright: 2018 Concert Audio Technologies Ltd+category: Data+build-type: Simple+extra-source-files: README.md+cabal-version: >=1.10++source-repository head+ type: git+ location: https://github.com/githubuser/attoparsec-varword++library+ hs-source-dirs: src+ ghc-options: -Wall+ default-extensions: BinaryLiterals+ , ScopedTypeVariables+ exposed-modules: Data.ByteString.Builder.Prim.VarWord+ , Data.ByteString.Builder.VarWord+ build-depends: base >= 4.7 && < 5+ , bytestring >= 0.9 && < 0.11+ default-language: Haskell2010++test-suite bytestring-builder-varword-test+ type: exitcode-stdio-1.0+ main-is: Spec.hs+ hs-source-dirs: test+ ghc-options: -threaded -rtsopts -with-rtsopts=-N -Wall+ default-extensions: BinaryLiterals+ , OverloadedStrings+ build-depends: base >= 4.7 && < 5+ , bytestring-builder-varword+ , attoparsec-varword >= 0.1 && < 0.2+ , attoparsec >= 0.10 && < 0.14+ , bytestring >= 0.9 && < 0.11+ , hspec >= 2.4.3 && < 2.5.0+ , QuickCheck >= 2.7 && < 2.11.4+ other-modules: Data.ByteString.Builder.VarWordSpec+ default-language: Haskell2010
+ src/Data/ByteString/Builder/Prim/VarWord.hs view
@@ -0,0 +1,71 @@+{- | Implementations of 'BoundedPrim' for several variable-length integer+ encodings. Rather than use these directly, consider the higher level+ "Data.ByteString.Builder.VarNum" 'Data.ByteString.Builder.Builder'+ interface.+-}+module Data.ByteString.Builder.Prim.VarWord+ ( varWordBe, denseVarWordBe+ , varWordLe+ ) where++import Data.Bits (Bits, shiftR, setBit, (.&.))+import Data.ByteString.Builder.Prim.Internal (BoundedPrim, boudedPrim)+import Data.Word+import Foreign.Ptr (Ptr, plusPtr)+import Foreign.Storable (Storable, poke, sizeOf)+++-- | 'BoundedPrim' for big-endian (most significant chunk first) variable length+-- encoding+varWordBe :: forall a. (Bits a, Integral a, Storable a) => BoundedPrim a+varWordBe = boundedPrim (sizeOf (undefined :: a)) go+ where+ go :: a -> Ptr Word8 -> IO (Ptr Word8)+ go a ptr = write7BitChunks (chunkWordBe a) ptr++-- | 'BoundedPrim' for big-endian (most significant chunk first) variable length+-- encoding where the continuation bit is also reused to pack information+-- slightly more densely.+denseVarWordBe :: forall a. (Bits a, Integral a, Storable a) => BoundedPrim a+denseVarWordBe = boundedPrim (sizeOf (undefined :: a)) go+ where+ go :: a -> Ptr Word8 -> IO (Ptr Word8)+ go a ptr = write7BitChunks (denseChunkWordBe a) ptr++-- | 'BoundedPrim' for little-endian (least significant chunk first) variable+-- length encoding+varWordLe :: forall a. (Bits a, Integral a, Storable a) => BoundedPrim a+varWordLe = boundedPrim (sizeOf (undefined :: a)) go+ where+ go :: a -> Ptr Word8 -> IO (Ptr Word8)+ go a ptr = write7BitChunks (chunkWordLe a) ptr++chunkWordBe :: (Bits a, Integral a) => a -> [Word8]+chunkWordBe = reverse . chunkWordLe' 0++denseChunkWordBe :: (Bits a, Integral a) => a -> [Word8]+denseChunkWordBe = reverse . chunkWordLe' 1++chunkWordLe :: (Bits a, Integral a) => a -> [Word8]+chunkWordLe = chunkWordLe' 0++chunkWordLe' :: (Bits a, Integral a) => a -> a -> [Word8]+chunkWordLe' contDec a =+ let+ highBits = shiftR a 7+ lowBits = a .&. 0b01111111+ in+ fromIntegral lowBits :+ if highBits == 0 then [] else chunkWordLe' contDec (highBits - contDec)++write7BitChunks :: [Word8] -> Ptr Word8 -> IO (Ptr Word8)+write7BitChunks [] ptr = return ptr+write7BitChunks (c:cs) ptr = do+ poke ptr $ case cs of+ [] -> c+ _ -> setBit c 7+ write7BitChunks cs $ plusPtr ptr 1++-- Fix a typo from the Builder.Prim.Internal:+boundedPrim :: Int -> (a -> Ptr Word8 -> IO (Ptr Word8)) -> BoundedPrim a+boundedPrim = boudedPrim
+ src/Data/ByteString/Builder/VarWord.hs view
@@ -0,0 +1,77 @@+{- | 'Builder's for several variable-length integer encoding schemes.+-}+module Data.ByteString.Builder.VarWord+ ( varWordBe, denseVarWordBe+ , varWordLe+ ) where++import Data.ByteString.Builder (Builder)+import Data.ByteString.Builder.Prim (primBounded)+import Data.Bits (Bits)++import Foreign.Storable (Storable)++import qualified Data.ByteString.Builder.Prim.VarWord as Prim+++-- | Produce a 'Builder' to encode an integer with a variable-length (chunked)+-- encoding. 7-bit chunks are produced in big-endian (most significant chunk+-- first) order, and each is prefixed with a continuation bit.+--+-- > 18464 == 1 0010000 0100000 ==+-- > (A) (B) (C)+-- >+-- > +-- Keep reading+-- > | +-- Keep reading+-- > | | +-- Stop+-- > v v v+-- > 10000001 10010000 00100000+-- > |<--->| |<--->| |<--->|+-- > (A) (B) (C)+--+-- >>> Builder.toLazyByteString $ varWordBe (18464 :: Word32)+-- "\129\144\32"+varWordBe :: (Bits a, Integral a, Storable a) => a -> Builder+varWordBe = primBounded Prim.varWordBe++-- | Produce a 'Builder' to encode an integer with a variable-length (chunked)+-- encoding. 7-bit chunks are produced in big-endian (most significant chunk+-- first) order, each is prefixed with a continuation bit, and the+-- continuation bit carries a further bit of information to reduce the size of+-- the resulting encoding.+--+-- > 34976 == 10 0010001 0100000 == 34976+-- > (A) (B) (C)+-- >+-- > +-- Keep reading+-- > | +-- Keep reading+-- > | | +-- Stop+-- > v v v+-- > 10000001 10010000 00100000+-- > |<--->| |<--->| |<--->|+-- > (A-1) (B-1) (C)+--+-- >>> Builder.toLazyByteString $ denseVarWordBe (34976 :: Word32)+-- "\129\144\32"+denseVarWordBe :: (Bits a, Integral a, Storable a) => a -> Builder+denseVarWordBe = primBounded Prim.denseVarWordBe++-- | Produce a 'Builder' to encode an integer with a varible-length (chunked)+-- encoding. 7-bit chunks are produced in little-endian (least significant+-- chunk first) order, and each is prefixed with a continuation bit.+--+-- > 526337 == 100000 0010000 0000001 ==+-- > (A) (B) (C)+-- >+-- > +-- Keep reading+-- > | +-- Keep reading+-- > | | +-- Stop+-- > v v v+-- > 10000001 10010000 00100000+-- > |<--->| |<--->| |<--->|+-- > (C) (B) (A)+--+-- >>> Builder.toLazyByteString $ varWordLe (526337 :: Word32)+-- "\129\144\32"+varWordLe :: (Bits a, Integral a, Storable a) => a -> Builder+varWordLe = primBounded Prim.varWordLe
+ test/Data/ByteString/Builder/VarWordSpec.hs view
@@ -0,0 +1,26 @@+module Data.ByteString.Builder.VarWordSpec where++import Test.Hspec++import Data.ByteString (ByteString)+import Data.ByteString.Builder (Builder)+import qualified Data.ByteString.Builder as Builder+import qualified Data.ByteString.Lazy as LBS+import Data.Word++import Data.ByteString.Builder.VarWord (varWordBe, denseVarWordBe, varWordLe)++spec :: Spec+spec = do+ varWordSpec "Big-endian chunked builder"+ varWordBe "\135\196\64"+ varWordSpec "Big-endian dense chunked builder"+ denseVarWordBe "\134\195\64"+ varWordSpec "Little-endian chunked builder"+ varWordLe "\192\196\7"++varWordSpec :: String -> (Word32 -> Builder) -> ByteString -> Spec+varWordSpec s b expected = describe s $ do+ it "should serialise a known number" $ do+ LBS.toStrict (Builder.toLazyByteString $ b 123456)+ `shouldBe` expected
+ test/Spec.hs view
@@ -0,0 +1,1 @@+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}