decompression_algorithm_zlib.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
*/
#ifndef PLUGIN_X_PROTOCOL_STREAM_COMPRESSION_DECOMPRESSION_ALGORITHM_ZLIB_H_
#definePLUGIN_X_PROTOCOL_STREAM_COMPRESSION_DECOMPRESSION_ALGORITHM_ZLIB_H_

#include"plugin/x/protocol/stream/compression/decompression_algorithm_interface.h"

#include"zlib.h"

#include"my_dbug.h"

namespaceprotocol {

classDecompression_algorithm_zlib : publicDecompression_algorithm_interface {
public:
Decompression_algorithm_zlib() {
 m_zstream.zalloc = nullptr;
 m_zstream.zfree = nullptr;
 m_zstream.opaque = nullptr;
 m_zstream.avail_in = 0;
 m_zstream.next_in = nullptr;
 m_zstream.avail_out = 0;
inflateInit(&m_zstream);
 }

~Decompression_algorithm_zlib() override { inflateEnd(&m_zstream); }

boolneeds_input() constoverride { return0 == m_zstream.avail_in; }

voidset_input(uint8_t *in_ptr, constint in_size) override {
DBUG_LOG("debug", "set_input(in_size:" << in_size << ")");
DBUG_DUMP("decompress_zlib", in_ptr, in_size);
 m_zstream.avail_in = in_size;
 m_zstream.next_in = in_ptr;
 }

booldecompress(uint8_t *out_ptr, int64_t *out_size) override {
 DBUG_TRACE;
DBUG_LOG("debug", "decompress(out_size:" << *out_size << ")");
int k_flush = m_zstream.avail_out ? Z_SYNC_FLUSH : Z_NO_FLUSH;

 m_zstream.avail_out = *out_size;
 m_zstream.next_out = out_ptr;

constauto result = inflate(&m_zstream, k_flush);
if (Z_OK != result) {
// Ignore STREAM END, on the next interaction if should return an
// error to client.
if (Z_STREAM_END != result) {
 m_valid = false;
DBUG_PRINT("info",
 ("inflate failed with result: %i, flush:%i, avail_out:%i",
static_cast<int>(result), static_cast<int>(k_flush),
static_cast<int>(m_zstream.avail_out)));

 *out_size = 0;
returnfalse;
 }
 }

 *out_size -= m_zstream.avail_out;

returntrue;
 }

boolwas_error() constoverride { return !m_valid; }

bool m_valid = true;
 z_stream m_zstream;
};

} // namespace protocol

#endif// PLUGIN_X_PROTOCOL_STREAM_COMPRESSION_DECOMPRESSION_ALGORITHM_ZLIB_H_