Copyright	© 2015 Herbert Valerio Riedel
License	BSD3
Maintainer	hvr@gnu.org
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Codec.Compression.Lzma

Contents

Simple (de)compression
Extended API with control over parameters
Monadic incremental (de)compression API
- Compression
- Decompression
Parameters
- Compression parameters
- Decompression parameters

Description

Compression and decompression of data streams in the lzma/xz format

See also the XZ Utils home page: http://tukaani.org/xz/

Synopsis

compress :: ByteString -> ByteString
decompress :: ByteString -> ByteString
compressWith :: CompressParams -> ByteString -> ByteString
decompressWith :: DecompressParams -> ByteString -> ByteString
data CompressStream m
- = CompressInputRequired (m (CompressStream m)) (ByteString -> m (CompressStream m))
- | CompressOutputAvailable !ByteString (m (CompressStream m))
- | CompressStreamEnd
compressIO :: CompressParams -> IO (CompressStream IO)
compressST :: CompressParams -> ST s (CompressStream (ST s))
data DecompressStream m
- = DecompressInputRequired (ByteString -> m (DecompressStream m))
- | DecompressOutputAvailable !ByteString (m (DecompressStream m))
- | DecompressStreamEnd ByteString
- | DecompressStreamError !LzmaRet
decompressIO :: DecompressParams -> IO (DecompressStream IO)
decompressST :: DecompressParams -> ST s (DecompressStream (ST s))
data LzmaRet
- = LzmaRetOK
- | LzmaRetStreamEnd
- | LzmaRetUnsupportedCheck
- | LzmaRetGetCheck
- | LzmaRetMemError
- | LzmaRetMemlimitError
- | LzmaRetFormatError
- | LzmaRetOptionsError
- | LzmaRetDataError
- | LzmaRetBufError
- | LzmaRetProgError
defaultCompressParams :: CompressParams
data CompressParams
compressIntegrityCheck :: CompressParams -> IntegrityCheck
compressLevel :: CompressParams -> CompressionLevel
compressLevelExtreme :: CompressParams -> Bool
data IntegrityCheck
- = IntegrityCheckNone
- | IntegrityCheckCrc32
- | IntegrityCheckCrc64
- | IntegrityCheckSha256
data CompressionLevel
- = CompressionLevel0
- | CompressionLevel1
- | CompressionLevel2
- | CompressionLevel3
- | CompressionLevel4
- | CompressionLevel5
- | CompressionLevel6
- | CompressionLevel7
- | CompressionLevel8
- | CompressionLevel9
defaultDecompressParams :: DecompressParams
data DecompressParams
decompressTellNoCheck :: DecompressParams -> Bool
decompressTellUnsupportedCheck :: DecompressParams -> Bool
decompressTellAnyCheck :: DecompressParams -> Bool
decompressConcatenated :: DecompressParams -> Bool
decompressAutoDecoder :: DecompressParams -> Bool
decompressMemLimit :: DecompressParams -> Word64

Simple (de)compression

compress :: ByteString -> ByteString #

Compress lazy ByteString into .xz format using defaultCompressParams.

decompress :: ByteString -> ByteString #

Decompress lazy ByteString from the .xz format

Extended API with control over parameters

compressWith :: CompressParams -> ByteString -> ByteString #

Like compress but with the ability to specify various compression parameters. Typical usage:

compressWith defaultCompressParams { compress... = ... }

decompressWith :: DecompressParams -> ByteString -> ByteString #

Like decompress but with the ability to specify various decompression parameters. Typical usage:

decompressWith defaultDecompressParams { decompress... = ... }

Monadic incremental (de)compression API

See zlib's incremental API documentation for more information.

Compression

data CompressStream m #

Constructors

CompressInputRequired (m (CompressStream m)) (ByteString -> m (CompressStream m))	Compression process requires input to proceed. You can either flush the stream (first field), supply an input chunk (second field), or signal the end of input (via empty chunk).
CompressOutputAvailable !ByteString (m (CompressStream m))	Output chunk available.
CompressStreamEnd

compressIO :: CompressParams -> IO (CompressStream IO) #

Incremental compression in the IO monad.

compressST :: CompressParams -> ST s (CompressStream (ST s)) #

Incremental compression in the lazy ST monad.

Decompression

data DecompressStream m #

Constructors

DecompressInputRequired (ByteString -> m (DecompressStream m))	Decoding process requires input to proceed. An empty `ByteString` chunk signals end of input.
DecompressOutputAvailable !ByteString (m (DecompressStream m))	Decompressed output chunk available.
DecompressStreamEnd ByteString	Decoded stream is finished. Any unconsumed leftovers from the input stream are returned via the `ByteString` field
DecompressStreamError !LzmaRet

decompressIO :: DecompressParams -> IO (DecompressStream IO) #

Incremental decompression in the IO monad.

decompressST :: DecompressParams -> ST s (DecompressStream (ST s)) #

Incremental decompression in the lazy ST monad.

data LzmaRet #

Constructors

LzmaRetOK
LzmaRetStreamEnd
LzmaRetUnsupportedCheck
LzmaRetGetCheck
LzmaRetMemError
LzmaRetMemlimitError
LzmaRetFormatError
LzmaRetOptionsError
LzmaRetDataError
LzmaRetBufError
LzmaRetProgError

Instances

Eq LzmaRet #
Instance details Defined in LibLzma Methods (==) :: LzmaRet -> LzmaRet -> Bool # (/=) :: LzmaRet -> LzmaRet -> Bool #
Ord LzmaRet #
Instance details Defined in LibLzma Methods compare :: LzmaRet -> LzmaRet -> Ordering # (<) :: LzmaRet -> LzmaRet -> Bool # (<=) :: LzmaRet -> LzmaRet -> Bool # (>) :: LzmaRet -> LzmaRet -> Bool # (>=) :: LzmaRet -> LzmaRet -> Bool # max :: LzmaRet -> LzmaRet -> LzmaRet # min :: LzmaRet -> LzmaRet -> LzmaRet #
Read LzmaRet #
Instance details Defined in LibLzma Methods readsPrec :: Int -> ReadS LzmaRet # readList :: ReadS [LzmaRet] # readPrec :: ReadPrec LzmaRet # readListPrec :: ReadPrec [LzmaRet] #
Show LzmaRet #
Instance details Defined in LibLzma Methods showsPrec :: Int -> LzmaRet -> ShowS # show :: LzmaRet -> String # showList :: [LzmaRet] -> ShowS #
Exception LzmaRet #
Instance details Defined in LibLzma Methods toException :: LzmaRet -> SomeException # fromException :: SomeException -> Maybe LzmaRet # displayException :: LzmaRet -> String #

Parameters

Compression parameters

defaultCompressParams :: CompressParams #

The default set of parameters for compression. This is typically used with the compressWith function with specific parameters overridden.

data CompressParams #

Set of parameters for compression. The defaults are defaultCompressParams.

Instances

Eq CompressParams #
Instance details Defined in LibLzma Methods (==) :: CompressParams -> CompressParams -> Bool # (/=) :: CompressParams -> CompressParams -> Bool #
Show CompressParams #
Instance details Defined in LibLzma Methods showsPrec :: Int -> CompressParams -> ShowS # show :: CompressParams -> String # showList :: [CompressParams] -> ShowS #

compressIntegrityCheck :: CompressParams -> IntegrityCheck #

CompressParams field: Specify type of integrity check

compressLevel :: CompressParams -> CompressionLevel #

CompressParams field: See documentation of CompressionLevel

compressLevelExtreme :: CompressParams -> Bool #

CompressParams field: Enable slower variant of the lzmaCompLevel preset, see xz(1) man-page for details.

data IntegrityCheck #

Integrity check type (only supported when compressing .xz files)

Constructors

IntegrityCheckNone	disable integrity check (not recommended)
IntegrityCheckCrc32	CRC32 using the polynomial from IEEE-802.3
IntegrityCheckCrc64	CRC64 using the polynomial from ECMA-182
IntegrityCheckSha256	SHA-256

Instances

Eq IntegrityCheck #
Instance details Defined in LibLzma Methods (==) :: IntegrityCheck -> IntegrityCheck -> Bool # (/=) :: IntegrityCheck -> IntegrityCheck -> Bool #
Ord IntegrityCheck #
Instance details Defined in LibLzma Methods compare :: IntegrityCheck -> IntegrityCheck -> Ordering # (<) :: IntegrityCheck -> IntegrityCheck -> Bool # (<=) :: IntegrityCheck -> IntegrityCheck -> Bool # (>) :: IntegrityCheck -> IntegrityCheck -> Bool # (>=) :: IntegrityCheck -> IntegrityCheck -> Bool # max :: IntegrityCheck -> IntegrityCheck -> IntegrityCheck # min :: IntegrityCheck -> IntegrityCheck -> IntegrityCheck #
Read IntegrityCheck #
Instance details Defined in LibLzma Methods readsPrec :: Int -> ReadS IntegrityCheck # readList :: ReadS [IntegrityCheck] # readPrec :: ReadPrec IntegrityCheck # readListPrec :: ReadPrec [IntegrityCheck] #
Show IntegrityCheck #
Instance details Defined in LibLzma Methods showsPrec :: Int -> IntegrityCheck -> ShowS # show :: IntegrityCheck -> String # showList :: [IntegrityCheck] -> ShowS #

data CompressionLevel #

Compression level presets that define the tradeoff between computational complexity and compression ratio

CompressionLevel0 has the lowest compression ratio as well as the lowest memory requirements, whereas CompressionLevel9 has the highest compression ratio and can require over 600MiB during compression (and over 60MiB during decompression). The man-page for xz(1) contains more detailed information with tables describing the properties of all compression level presets.

CompressionLevel6 is the default setting in defaultCompressParams as it provides a good trade-off and matches the default of the xz(1) tool.

Constructors

CompressionLevel0
CompressionLevel1
CompressionLevel2
CompressionLevel3
CompressionLevel4
CompressionLevel5
CompressionLevel6
CompressionLevel7
CompressionLevel8
CompressionLevel9

Instances

Enum CompressionLevel #
Instance details Defined in LibLzma Methods succ :: CompressionLevel -> CompressionLevel # pred :: CompressionLevel -> CompressionLevel # toEnum :: Int -> CompressionLevel # fromEnum :: CompressionLevel -> Int # enumFrom :: CompressionLevel -> [CompressionLevel] # enumFromThen :: CompressionLevel -> CompressionLevel -> [CompressionLevel] # enumFromTo :: CompressionLevel -> CompressionLevel -> [CompressionLevel] # enumFromThenTo :: CompressionLevel -> CompressionLevel -> CompressionLevel -> [CompressionLevel] #
Eq CompressionLevel #
Instance details Defined in LibLzma Methods (==) :: CompressionLevel -> CompressionLevel -> Bool # (/=) :: CompressionLevel -> CompressionLevel -> Bool #
Ord CompressionLevel #
Instance details Defined in LibLzma Methods compare :: CompressionLevel -> CompressionLevel -> Ordering # (<) :: CompressionLevel -> CompressionLevel -> Bool # (<=) :: CompressionLevel -> CompressionLevel -> Bool # (>) :: CompressionLevel -> CompressionLevel -> Bool # (>=) :: CompressionLevel -> CompressionLevel -> Bool # max :: CompressionLevel -> CompressionLevel -> CompressionLevel # min :: CompressionLevel -> CompressionLevel -> CompressionLevel #
Read CompressionLevel #
Instance details Defined in LibLzma Methods readsPrec :: Int -> ReadS CompressionLevel # readList :: ReadS [CompressionLevel] # readPrec :: ReadPrec CompressionLevel # readListPrec :: ReadPrec [CompressionLevel] #
Show CompressionLevel #
Instance details Defined in LibLzma Methods showsPrec :: Int -> CompressionLevel -> ShowS # show :: CompressionLevel -> String # showList :: [CompressionLevel] -> ShowS #

Decompression parameters

defaultDecompressParams :: DecompressParams #

The default set of parameters for decompression. This is typically used with the decompressWith function with specific parameters overridden.

data DecompressParams #

Set of parameters for decompression. The defaults are defaultDecompressParams.

Instances

Eq DecompressParams #
Instance details Defined in LibLzma Methods (==) :: DecompressParams -> DecompressParams -> Bool # (/=) :: DecompressParams -> DecompressParams -> Bool #
Show DecompressParams #
Instance details Defined in LibLzma Methods showsPrec :: Int -> DecompressParams -> ShowS # show :: DecompressParams -> String # showList :: [DecompressParams] -> ShowS #

decompressTellNoCheck :: DecompressParams -> Bool #

DecompressParams field: If set, abort if decoded stream has no integrity check.

decompressTellUnsupportedCheck :: DecompressParams -> Bool #

DecompressParams field: If set, abort (via LzmaRetGetCheck) if decoded stream integrity check is unsupported.

decompressTellAnyCheck :: DecompressParams -> Bool #

DecompressParams field: If set, abort (via LzmaRetGetCheck) as soon as the type of the integrity check has been detected.

decompressConcatenated :: DecompressParams -> Bool #

DecompressParams field: If set, concatenated files as decoded seamless.

decompressAutoDecoder :: DecompressParams -> Bool #

DecompressParams field: If set, legacy .lzma-encoded streams are allowed too.

decompressMemLimit :: DecompressParams -> Word64 #

DecompressParams field: decompressor memory limit. Set to maxBound to disable memory limit.