Submodule compress.lz4

The compress.lz4 submodule provides the ability to compress and decompress data using the lz4 algorithm. You can use the lz4 compressor as follows:

1. Create a compressor instance using the compress.lz4.new() function:

    
   local lz4_compressor = require('compress.lz4').new()-- or --local lz4_compressor = require('compress').lz4.new()

   Optionally, you can pass compression options (lz4_opts) specific for lz4:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

2. To compress the specified data, use the compress() method:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

3. To decompress data, call decompress():

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

Below is a list of the compress.lz4 functions and objects.

Create a lz4 compressor instance.

Parameters:

• lz4_opts (table) — lz4 compression options (see lz4_opts)

Returns

a new lz4 compressor instance (see lz4_compressor)

Return type

userdata

Example:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

A compressor instance that exposes the API for compressing and decompressing data using the lz4 algorithm. To create the lz4 compressor, call compress.lz4.new().

Compress the specified data.

Parameters:

• data (string) — data to be compressed

Returns

compressed data

Return type

string

Example:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

Decompress the specified data.

Parameters:

• data (string) — data to be decompressed

Returns

decompressed data

Return type

string

Example:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

Configuration options of the lz4_compressor. These options can be passed to the compress.lz4.new() function.

Example:

 
local lz4_compressor = require('compress.lz4').new({    acceleration = 1000,    decompress_buffer_size = 2097152})compressed_data = lz4_compressor:compress('Hello world!')decompressed_data = lz4_compressor:decompress(compressed_data)print(decompressed_data)

Specifies the acceleration factor that enables you to adjust the compression ratio and speed. The higher acceleration factor increases the compression speed but decreases the compression ratio.

• Default: 1
• Maximum: 65537
• Minimum: 1

Specifies the decompress buffer size (in bytes). If the size of decompressed data is larger than this value, the compressor returns an error on decompression.

• Default: 1048576