my_compress.h

/* Copyright (c) 2019, 2025, Oracle and/or its affiliates.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License, version 2.0,
 as published by the Free Software Foundation.

 This program is designed to work with certain software (including
 but not limited to OpenSSL) that is licensed under separate terms,
 as designated in a particular file or component or in included license
 documentation. The authors of MySQL hereby grant you an additional
 permission to link the program and your derivative works with the
 separately licensed software that they have either included with
 the program or referenced in the documentation.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 GNU General Public License, version 2.0, for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */

#ifndefMY_COMPRESS_INCLUDED
#defineMY_COMPRESS_INCLUDED

/* List of valid values for compression_algorithm */
enumenum_compression_algorithm {
MYSQL_UNCOMPRESSED=1,
MYSQL_ZLIB,
MYSQL_ZSTD,
MYSQL_INVALID
};

/**
 Compress context information. relating to zlib compression.
*/

typedefstructmysql_zlib_compress_context {
/**
 Compression level to use in zlib compression.
 */
unsigned intcompression_level;
} mysql_zlib_compress_context;

typedefstructZSTD_CCtx_sZSTD_CCtx;
typedefstructZSTD_DCtx_sZSTD_DCtx;

/**
 Compress context information relating to zstd compression.
*/

typedefstructmysql_zstd_compress_context {
/**
 Pointer to compressor context.
 */
ZSTD_CCtx*cctx;
/**
 Pointer to decompressor context.
 */
ZSTD_DCtx*dctx;
/**
 Compression level to use in zstd compression.
 */
unsigned intcompression_level;
} mysql_zstd_compress_context;

/**
 Compression context information.
 It encapsulate the context information based on compression method and
 presents a generic struct.
*/

typedefstructmysql_compress_context {
enumenum_compression_algorithmalgorithm; ///< Compression algorithm name.
union {
mysql_zlib_compress_contextzlib_ctx; ///< Context information of zlib.
mysql_zstd_compress_contextzstd_ctx; ///< Context information of zstd.
 } u;
} mysql_compress_context;

/**
 Get default compression level corresponding to a given compression method.

 @param algorithm Compression Method. Possible values are zlib or zstd.

 @return an unsigned int representing default compression level.
 6 is the default compression level for zlib and 3 is the
 default compression level for zstd.
*/

unsigned intmysql_default_compression_level(
enumenum_compression_algorithmalgorithm);

/**
 Initialize a compress context object to be associated with a NET object.

 @param cmp_ctx Pointer to compression context.
 @param algorithm Compression algorithm.
 @param compression_level Compression level corresponding to the compression
 algorithm.
*/

voidmysql_compress_context_init(mysql_compress_context*cmp_ctx,
enumenum_compression_algorithmalgorithm,
unsigned intcompression_level);
/**
 Deinitialize the compression context allocated.

 @param mysql_compress_ctx Pointer to Compression context.
*/

voidmysql_compress_context_deinit(mysql_compress_context*mysql_compress_ctx);

#endif// MY_COMPRESS_INCLUDED