@eryx/compression/gzip Module

Gzip helpers: compress/decompress and header inspection utilities.

Summary

Classes

Compressor
Compressor:write(data: buffer, flush: number?) → buffer
Compressor:finish() → buffer
Compressor:close() → ()
Decompressor
Decompressor:write(data: buffer) → (buffer, boolean)
Decompressor:close() → ()

Functions

gzip.compress(data: buffer, level: number?) → buffer
gzip.compressEx(data: buffer, options: CompressExOptions) → buffer
gzip.decompress(data: buffer) → buffer
gzip.isGzip(data: buffer) → boolean
gzip.readHeader(data: buffer) → GzipHeader
gzip.createCompressor(level: number?) → Compressor
gzip.createDecompressor() → Decompressor

API Reference

Classes

Compressor

A streaming gzip compressor. Feed data incrementally with write, then call finish to produce the final gzip output.

Properties

Compressor:write

Compressor:write(data: buffer, flush: number?) → buffer

Compressor:finish

Compressor:finish() → buffer

Compressor:close

Compressor:close() → ()

Decompressor

A streaming gzip decompressor. Feed compressed chunks with write; the second return value indicates when the stream is complete.

Properties

Decompressor:write

Decompressor:write(data: buffer) → (buffer, boolean)

Decompressor:close

Decompressor:close() → ()

Functions

gzip.compress

Standard gzip compress.

gzip.compress(data: buffer, level: number?) → buffer

Parameters

data: buffer

input bytes to compress

level: number?

compression level (NO_COMPRESSION..BEST_COMPRESSION)

Returns

buffer

gzip-wrapped compressed bytes

gzip.compressEx

Gzip compress with a custom header (filename, timestamp, OS, comment).

gzip.compressEx(data: buffer, options: CompressExOptions) → buffer

Parameters

data: buffer

input bytes to compress

options: CompressExOptions

header and compression options

Returns

buffer

gzip-wrapped compressed bytes

gzip.decompress

Gzip decompress.

gzip.decompress(data: buffer) → buffer

Parameters

data: buffer

gzip stream to decompress

Returns

buffer

decompressed bytes

gzip.isGzip

Returns true if the buffer starts with the gzip magic bytes (0x1F 0x8B).

gzip.isGzip(data: buffer) → boolean

Parameters

data: buffer

data to inspect

Returns

boolean

true when buffer looks like gzip

gzip.readHeader

Parses the gzip header fields without decompressing the payload.

gzip.readHeader(data: buffer) → GzipHeader

Parameters

data: buffer

gzip stream

Returns

GzipHeader

parsed header fields

gzip.createCompressor

Creates a streaming gzip compressor.

gzip.createCompressor(level: number?) → Compressor

Parameters

level: number?

compression level

Returns

Compressor

the streaming compressor

gzip.createDecompressor

Creates a streaming gzip decompressor.

gzip.createDecompressor() → Decompressor

Returns

Decompressor

the streaming decompressor

Types

GzipHeader
type GzipHeader = { method: number, flags: number, mtime: number, xfl: number, os: number, name: string?, comment: string?, extra: buffer?, headerCrc16: number?, dataOffset: number }
method: number
flags: number
mtime: number
xfl: number
os: number
name: string?
comment: string?
extra: buffer?
headerCrc16: number?
dataOffset: number

CompressExOptions
type CompressExOptions = { level: number?, name: string?, comment: string?, mtime: number?, os: number? }
level: number?
name: string?
comment: string?
mtime: number?
os: number?

Constants