zstd - Zstandard Compression Library

This directory contains the zstd compression library used by ProxySQL for compressed protocol support in MySQL and PostgreSQL connections.

Source

Project: https://github.com/facebook/zstd
Version: 1.5.7
License: BSD-3-Clause / GPL-2.0-only (dual licensed)

Build

The library is built automatically by the ProxySQL build system:

bash

cd deps/zstd && tar -zxf zstd-1.5.7.tar.gz
cd zstd/zstd/lib && make libzstd.a

Static Linking

zstd is statically linked into ProxySQL to eliminate runtime dependencies on system libraries. This ensures consistent behavior across different platforms (Linux, macOS, FreeBSD).

Usage in ProxySQL

MySQL compressed protocol (mysql_compression)
PostgreSQL compressed protocol support
Used by mysql_data_stream.cpp and MySQL_Protocol.cpp