A streaming Zstandard compressor.
@class Compressor
@eryx/compression/zstd Module
JSON
Zstandard compression helpers: compress/decompress and dictionary support.
Summary
Classes
Functions
API Reference
Classes
Compressor
Properties
Compressor:write
Compressor:write(data: buffer) → buffer
Compressor:flush
Compressor:flush() → buffer
Compressor:finish
Compressor:finish() → buffer
Compressor:close
Compressor:close() → ()
Decompressor
A streaming Zstandard decompressor.
@class Decompressor
Properties
Decompressor:write
Decompressor:write(data: buffer) → (buffer, boolean)
Decompressor:close
Decompressor:close() → ()
Functions
zstd.compress
Compress data with Zstandard.
zstd.compress(data: buffer, level: number?) → buffer
Parameters
data: buffer
input bytes to compress
level: number?
compression level (CLEVEL_MIN..CLEVEL_MAX)
Returns
buffer
compressed zstd frame level: CLEVEL_MIN (negative, ultra-fast) - CLEVEL_MAX (22, best). Default CLEVEL_DEFAULT (3). Negative levels trade ratio for extreme speed.
zstd.decompress
Decompress a Zstandard frame.
zstd.decompress(data: buffer) → buffer
Parameters
data: buffer
zstd frame to decompress
Returns
buffer
decompressed bytes Uses the content size embedded in the frame header when available (fast path).
zstd.compressBound
Upper bound on compressed output size for len input bytes.
zstd.compressBound(len: number) → number
Parameters
len: number
input length in bytes
Returns
number
upper bound on compressed size
zstd.frameContentSize
Returns the decompressed size stored in the frame header, or nil if it was not stored (compressed with contentSize=0) or the frame is invalid.
zstd.frameContentSize(data: buffer) → number?
Parameters
data: buffer
zstd frame
Returns
number?
decompressed size or nil
zstd.compressWithDict
Compress using a pre-trained dictionary. The same dictionary must be supplied to decompressWithDict.
zstd.compressWithDict(data: buffer, dict: buffer, level: number?) → buffer
Parameters
data: buffer
input bytes
dict: buffer
dictionary data
level: number?
compression level
Returns
buffer
compressed frame
zstd.decompressWithDict
Decompress using a pre-trained dictionary.
zstd.decompressWithDict(data: buffer, dict: buffer) → buffer
Parameters
data: buffer
compressed frame
dict: buffer
dictionary data used for compression
Returns
buffer
decompressed bytes
zstd.trainDictionary
Train a Zstandard dictionary from an array of sample buffers.
zstd.trainDictionary(samples: { buffer }, capacity: number) → buffer
Parameters
samples: { buffer }
representative examples of data
capacity: number
desired dictionary size in bytes
Returns
buffer
trained dictionary samples: { buffer } - representative examples of data you plan to compress. capacity: desired dictionary size in bytes (e.g. 112640 = 110 KB). Returns a dictionary buffer ready to pass to compress/decompressWithDict.
zstd.createCompressor
Creates a streaming Zstandard compressor.
Parameters
level: number?
compression level (CLEVEL_MIN..CLEVEL_MAX)
Returns
the streaming compressor
zstd.createDecompressor
Creates a streaming Zstandard decompressor.
Returns
the streaming decompressor
Constants
zstd.CLEVEL_MAX=22zstd.CLEVEL_DEFAULT=3