lzip-0.0.0.0: Lzip compression / Lzlib bindings

Safe HaskellNone
LanguageHaskell2010

Codec.Compression.Lzlib

Contents

Description

Mid-level FFI bindings in the IO monad to lzlib.

See also Codec.Compression.Lzlib.ST for the ST monad version.

Synopsis

Compression functions

data LzEncoder Source #

lzlib compressor handle.

data CompressParams Source #

Parameters for lzip compressor

If compressDictionarySize is 65535 and compressMatchLenLimit is 16, the "fast variant" of LZMA is chosen.

Constructors

CompressParams 

Fields

compressParamPreset :: Int -> CompressParams Source #

Construct CompressParams based on the standard preset levels used by the lzip command-line interface.

The table below shows the parameters as a function of the level input argument:

level compressDictionarySize compressMatchLenLimit
≤0 65535 bytes 16 bytes
1 1 MiB 5 bytes
2 1.5 MiB 6 bytes
3 2 MiB 8 bytes
4 3 MiB 12 bytes
5 4 MiB 20 bytes
6 8 MiB 36 bytes
7 16 MiB 68 bytes
8 24 MiB 132 bytes
≥9 32 MiB 273 bytes

compressMemberSize is set to its maximum allowed value (i.e. 2 PiB) for all compression levels.

NOTE: The "0" preset parameters will cause the encoder to use the "fast variant" of the LZMA algorithm.

lzCompressOpen :: CompressParams -> IO (Either LzErrno LzEncoder) Source #

Construct new LzEncoder.

If a LzEncoder was constructed succesfully it will be in the LzOk state (as reported by lzCompressErrno).

NOTE: lzCompressClose will be invoked automatically when LzEncoder is garbage collected.

lzCompressClose :: LzEncoder -> IO () Source #

Promptly finalize a LzEncoder.

It is not necessary to invoke lzCompressClose explicitly as it will be invoked implicitly when a LzEncoder is garbage collected.

See also lzCompressOpen.

lzCompressRead :: LzEncoder -> Int -> IO ByteString Source #

Retrieve up to n bytes of the compressed stream from the encoder.

Returns the empty ByteString when the output buffer has been drained.

lzCompressWrite :: LzEncoder -> ByteString -> IO Int Source #

Push uncompressed data into the encoder. The return value is the number of bytes actually consumed.

lzCompressSyncFlush :: LzEncoder -> IO LzErrno Source #

Force the encoder to output the compressed stream for all the uncompressed input data.

After this operation, the output buffer has to be drained via repeated invocations of lzCompressRead.

lzCompressFinish :: LzEncoder -> IO LzErrno Source #

Finalize current member.

After this operation, the output buffer has to be drained via repeated invocations of lzCompressRead.

See also lzCompressFinished and lzCompressMemberFinished.

lzCompressFinished :: LzEncoder -> IO Bool Source #

Returns True if the output buffer has been drained completely (which implies lzCompressMemberFinished).

lzCompressMemberFinished :: LzEncoder -> IO Bool Source #

Returns True if the output buffer has been drained completely and lzCompressRestartMember can be invoked.

lzCompressRestartMember :: LzEncoder -> Word64 -> IO LzErrno Source #

Start a new member in a multimember compression stream.

Must only be called when lzCompressMemberFinished is True.

Decompression functions

data LzDecoder Source #

lzlib decompressor handle.

lzDecompressOpen :: IO (Either LzErrno LzDecoder) Source #

Construct new LzDecoder.

If a LzDecoder was constructed succesfully it will be in the LzOk state (as reported by lzDecompressErrno).

NOTE: lzDecompressClose will be invoked automatically when LzDecoder is garbage collected.

lzDecompressClose :: LzDecoder -> IO () Source #

Promptly finalize a LzDecoder.

It is not necessary to invoke lzDecompressClose explicitly as it will be invoked implicitly when a LzDecoder is garbage collected.

See also lzDecompressOpen.

lzDecompressRead :: LzDecoder -> Int -> IO ByteString Source #

Retrieve up to n bytes of the decompressed stream from the decoder.

Returns the empty ByteString when the output buffer has been drained.

lzDecompressWrite :: LzDecoder -> ByteString -> IO Int Source #

Push compressed data into the decoder. The return value is the number of bytes actually consumed.

lzDecompressSyncToMember :: LzDecoder -> IO LzErrno Source #

Instruct decoder to discard data of current member and skip till next member.

This is a no-op if the decoder is already at the start of a member.

lzDecompressFinish :: LzDecoder -> IO LzErrno Source #

Finalize current member.

After this operation, the output buffer has to be drained via repeated invocations of lzDecompressRead.

See also lzDecompressFinished and lzDecompressMemberFinished.

lzDecompressFinished :: LzDecoder -> IO Bool Source #

Returns True if the output buffer has been drained completely (which implies lzDecompressMemberFinished).

lzDecompressMemberFinished :: LzDecoder -> IO Bool Source #

Returns True if the output buffer has been drained completely and lzDecompressRestartMember can be invoked.

lzDecompressReset :: LzDecoder -> IO LzErrno Source #

Reset LzEncoder into the initial state (as if lzCompressOpen had just been invoked) and discard all data.

Error codes