The ZLibEncoder encoder is used by ZLibCodec and GZipCodec to compress data.



ZLibEncoder({bool gzip: false, int level: ZLibOption.DEFAULT_LEVEL, int windowBits: ZLibOption.DEFAULT_WINDOW_BITS, int memLevel: ZLibOption.DEFAULT_MEM_LEVEL, int strategy: ZLibOption.STRATEGY_DEFAULT, List<int> dictionary: null, bool raw: false })


dictionary List<int>

Initial compression dictionary.

gzip bool

When true, GZip frames will be added to the compressed data.

level int

The compression-level can be set in the range of -1..9, with 6 being the default compression level. Levels above 6 will have higher compression rates at the cost of more CPU and memory usage. Levels below 6 will use less CPU and memory at the cost of lower compression rates.

memLevel int

Specifies how much memory should be allocated for the internal compression state. 1 uses minimum memory but is slow and reduces compression ratio; 9 uses maximum memory for optimal speed. The default value is 8.

raw bool

When true, deflate generates raw data with no zlib header or trailer, and will not compute an adler32 check value

strategy int

Tunes the compression algorithm. Use the value ZLibOption.STRATEGY_DEFAULT for normal data, ZLibOption.STRATEGY_FILTERED for data produced by a filter (or predictor), ZLibOption.STRATEGY_HUFFMAN_ONLY to force Huffman encoding only (no string match), or ZLibOption.STRATEGY_RLE to limit match distances to one (run-length encoding).

windowBits int

Base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15. Larger values result in better compression at the expense of memory usage. The default value is 15

hashCode int

The hash code for this object.

read-only, inherited
runtimeType Type

A representation of the runtime type of the object.

read-only, inherited


operator ==(other) bool

The equality operator.



convert(List<int> bytes) List<int>

Convert a list of bytes using the options given to the ZLibEncoder constructor.

startChunkedConversion(Sink<List<int>> sink) ByteConversionSink

Start a chunked conversion using the options given to the ZLibEncoder constructor. While it accepts any Sink taking List<int>'s, the optimal sink to be passed as sink is a ByteConversionSink.

bind(Stream<List<int>> stream) Stream<List<int>>

Transforms the provided stream.

fuse<TT>(Converter<List<int>, TT> other) Converter<List<int>, TT>

Fuses this with other.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a non-existent method or property is accessed.

toString() String

Returns a string representation of this object.