System.IO.Streams.Lzma

Simple IO-Streams interface for lzma/xz compression

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

ByteString decompression

decompress :: InputStream ByteString -> IO (InputStream ByteString)

Decompress an InputStream of strict ByteStrings from the .xz format

decompressWith :: DecompressParams -> InputStream ByteString -> IO (InputStream ByteString)

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

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

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.

Constructors

DecompressParams

Fields

decompressTellNoCheck :: !Bool

decompressTellUnsupportedCheck :: !Bool

decompressTellAnyCheck :: !Bool

decompressConcatenated :: !Bool

decompressAutoDecoder :: !Bool

decompressMemLimit :: !Word64

Set to maxBound to disable memory limit

Instances

Eq DecompressParams

Show DecompressParams

ByteString compression

compress :: OutputStream ByteString -> IO (OutputStream ByteString)

Convert an OutputStream that consumes compressed ByteStrings (in the .xz format) into an OutputStream that consumes uncompressed ByteStrings

compressWith :: CompressParams -> OutputStream ByteString -> IO (OutputStream ByteString)

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

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

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.

Constructors

CompressParams

Fields

compressIntegrityCheck :: !IntegrityCheck

Specify type of integrity check

compressLevel :: !CompressionLevel

See documentation of CompressionLevel

compressLevelExtreme :: !Bool

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

Instances

Eq CompressParams

Show CompressParams

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

Ord IntegrityCheck

Show IntegrityCheck

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

Eq CompressionLevel

Ord CompressionLevel

Show CompressionLevel