kjdev / zstd
A compression/decompression with Zstandard
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Language:C
Type:php-ext
Requires
- php: >= 7.0.0
This package is auto-updated.
Last update: 2025-06-11 22:59:53 UTC
README
This extension allows Zstandard.
Documentation for Zstandard can be found at » https://github.com/facebook/zstd.
Build from sources
% git clone --recursive --depth=1 https://github.com/kjdev/php-ext-zstd.git
% cd php-ext-zstd
% phpize
% ./configure
% make
% make install
To use the system library
% ./configure --with-libzstd
minimum system libzstd library version to 1.4.0
Install from pecl:
% pecl install zstd
Distribution binary packages
Fedora
Fedora users can install the » php-zstd package from official repository.
dnf install php-zstd
CentOS / RHEL
CentOS / RHEL (and other clones) users can install the » php-zstd package from » EPEL repository.
yum install php-zstd
Other RPM packages of this extension, for other PHP versions, are available in » Remi's RPM repository.
Configration
php.ini:
extension=zstd.so
Output handler option
| Name | Default | Changeable |
|---|---|---|
| zstd.output_compression | 0 | PHP_INI_ALL |
| zstd.output_compression_level | -1 | PHP_INI_ALL |
| zstd.output_compression_dict | "" | PHP_INI_ALL |
-
zstd.output_compression boolean/integer
Whether to transparently compress pages. If this option is set to "On" in php.ini or the Apache configuration, pages are compressed if the browser sends an "Accept-Encoding: zstd" header. "Content-Encoding: zstd" and "Vary: Accept-Encoding" headers are added to the output. In runtime, it can be set only before sending any output.
-
zstd.output_compression_level integer
Compression level used for transparent output compression. Specify a value between 0 to 22. The default value of -1 uses internally defined values (3).
-
zstd.output_compression_dict string
Specifies the path to the compressed dictionary file to be used by the output handler.
Constant
| Name | Description |
|---|---|
| ZSTD_COMPRESS_LEVEL_MIN | Minimal compress level value |
| ZSTD_COMPRESS_LEVEL_MAX | Maximal compress level value |
| ZSTD_COMPRESS_LEVEL_DEFAULT | Default compress level value |
| LIBZSTD_VERSION_NUMBER | libzstd version number |
| LIBZSTD_VERSION_STRING | libzstd version string |
Function
- zstd_compress — Zstandard compression
- zstd_uncompress — Zstandard decompression
- zstd_compress_dict — Zstandard compression using a digested dictionary
- zstd_uncompress_dict — Zstandard decompression using a digested dictionary
- zstd_compress_init — Initialize an incremental compress context
- zstd_compress_add — Incrementally compress data
- zstd_uncompress_init — Initialize an incremental uncompress context
- zstd_uncompress_add — Incrementally uncompress data
zstd_compress — Zstandard compression
Description
string zstd_compress ( string $data [, int $level = 3 ] )
Zstandard compression.
Parameters
-
data
The string to compress.
-
level
The level of compression (1-22). (Defaults to 3)
A value smaller than 0 means a faster compression level. (Zstandard library 1.3.4 or later)
Return Values
Returns the compressed data or FALSE if an error occurred.
zstd_uncompress — Zstandard decompression
Description
string zstd_uncompress ( string $data )
Zstandard decompression.
Alias: zstd_decompress
Parameters
-
data
The compressed string.
Return Values
Returns the decompressed data or FALSE if an error occurred.
zstd_compress_dict — Zstandard compression using a digested dictionary
Description
string zstd_compress_dict ( string $data , string $dict [, int $level = 3 ])
Zstandard compression using a digested dictionary.
Alias: zstd_compress_usingcdict
Parameters
-
data
The string to compress.
-
dict
The Dictionary data.
-
level
The level of compression (1-22). (Defaults to 3)
Return Values
Returns the compressed data or FALSE if an error occurred.
zstd_uncompress_dict — Zstandard decompression using a digested dictionary
Description
string zstd_uncompress_dict ( string $data , string $dict )
Zstandard decompression using a digested dictionary.
Alias: zstd_decompress_dict, zstd_uncompress_usingcdict, zstd_decompress_usingcdict
Parameters
-
data
The compressed string.
-
dict
The Dictionary data.
Return Values
Returns the decompressed data or FALSE if an error occurred.
zstd_compress_init — Initialize an incremental compress context
Description
Zstd\Compress\Context zstd_compress_init ( [ int $level = ZSTD_COMPRESS_LEVEL_DEFAULT ] )
Initialize an incremental compress context
Parameters
-
level
The higher the level, the slower the compression. (Defaults to
ZSTD_COMPRESS_LEVEL_DEFAULT)
Return Values
Returns a zstd context instance on success, or FALSE on failure
zstd_compress_add — Incrementally compress data
Description
string zstd_compress_add ( Zstd\Compress\Context $context, string $data [, bool $end = false ] )
Incrementally compress data
Parameters
-
context
A context created with
zstd_compress_init(). -
data
A chunk of data to compress.
-
end
Set to true to terminate with the last chunk of data.
Return Values
Returns a chunk of compressed data, or FALSE on failure.
zstd_uncompress_init — Initialize an incremental uncompress context
Description
Zstd\UnCompress\Context zstd_uncompress_init ( void )
Initialize an incremental uncompress context
Return Values
Returns a zstd context instance on success, or FALSE on failure
zstd_uncompress_add — Incrementally uncompress data
Description
string zstd_uncompress_add ( Zstd\UnCompress\Context $context, string $data )
Incrementally uncompress data
Parameters
-
context
A context created with
zstd_uncompress_init(). -
data
A chunk of compressed data.
Return Values
Returns a chunk of uncompressed data, or FALSE on failure.
Namespace
Namespace Zstd;
function compress( $data [, $level = 3 ] )
function uncompress( $data )
function compress_dict ( $data, $dict )
function uncompress_dict ( $data, $dict )
function compress_init ( [ $level = 3 ] )
function compress_add ( $context, $data [, $end = false ] )
function uncompress_init ()
function uncompress_add ( $context, $data )
zstd_compress, zstd_uncompress, zstd_compress_dict,
zstd_uncompress_dict, zstd_compress_init, zstd_compress_add,
zstd_uncompress_init and zstd_uncompress_add function aliases.
Streams
Zstd compression and decompression are available using the
compress.zstd:// stream prefix.
Output handler
ini_set('zstd.output_compression', 'On'); // OR // ob_start('ob_zstd_handler'); echo ...;
"Accept-Encoding: zstd" must be specified.
Examples
// Using functions $data = zstd_compress('test'); zstd_uncompress($data); // Using namespaced functions $data = \Zstd\compress('test'); \Zstd\uncompress($data); // Using streams file_put_contents("compress.zstd:///path/to/data.zstd", $data); readfile("compress.zstd:///path/to/data.zstd"); // Providing level of compression, when using streams $context = stream_context_create([ 'zstd' => [ 'level' => ZSTD_COMPRESS_LEVEL_MIN, ], ], ); file_put_contents("compress.zstd:///path/to/data.zstd", $data, context: $context); readfile("compress.zstd:///path/to/data.zstd", context: $context);