mariadb/plugin/semisync/semisync_slave.cc

/* Copyright (C) 2008 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   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 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 */


#include "semisync_slave.h"

char rpl_semi_sync_slave_enabled;
char rpl_semi_sync_slave_status= 0;
unsigned long rpl_semi_sync_slave_trace_level;

int ReplSemiSyncSlave::initObject()
{
  int result= 0;
  const char *kWho = "ReplSemiSyncSlave::initObject";

  if (init_done_)
  {
    fprintf(stderr, "%s called twice\n", kWho);
    return 1;
  }
  init_done_ = true;

  /* References to the parameter works after set_options(). */
  setSlaveEnabled(rpl_semi_sync_slave_enabled);
  setTraceLevel(rpl_semi_sync_slave_trace_level);

  return result;
}

int ReplSemiSyncSlave::slaveReplyConnect()
{
  if (!mysql_reply && !(mysql_reply= rpl_connect_master(NULL)))
  {
    sql_print_error("Semisync slave connect to master for reply failed");
    return 1;
  }
  return 0;
}

int ReplSemiSyncSlave::slaveReadSyncHeader(const char *header,
                                      unsigned long total_len,
                                      bool  *need_reply,
                                      const char **payload,
                                      unsigned long *payload_len)
{
  const char *kWho = "ReplSemiSyncSlave::slaveReadSyncHeader";
  int read_res = 0;
  function_enter(kWho);

  if ((unsigned char)(header[0]) == kPacketMagicNum)
  {
    *need_reply  = (header[1] & kPacketFlagSync);
    *payload_len = total_len - 2;
    *payload     = header + 2;

    if (trace_level_ & kTraceDetail)
      sql_print_information("%s: reply - %d", kWho, *need_reply);
  }
  else
  {
    sql_print_error("Missing magic number for semi-sync packet, packet "
                    "len: %lu", total_len);
    read_res = -1;
  }

  return function_exit(kWho, read_res);
}

int ReplSemiSyncSlave::slaveStart(Binlog_relay_IO_param *param)
{
  bool semi_sync= getSlaveEnabled();
  
  sql_print_information("Slave I/O thread: Start %s replication to\
 master '%s@%s:%d' in log '%s' at position %lu",
			semi_sync ? "semi-sync" : "asynchronous",
			param->user, param->host, param->port,
			param->master_log_name[0] ? param->master_log_name : "FIRST",
			(unsigned long)param->master_log_pos);

  if (semi_sync && !rpl_semi_sync_slave_status)
    rpl_semi_sync_slave_status= 1;
  return 0;
}

int ReplSemiSyncSlave::slaveStop(Binlog_relay_IO_param *param)
{
  if (rpl_semi_sync_slave_status)
    rpl_semi_sync_slave_status= 0;
  if (mysql_reply)
    mysql_close(mysql_reply);
  mysql_reply= 0;
  return 0;
}

int ReplSemiSyncSlave::slaveReply(const char *log_name, my_off_t log_pos)
{
  char query[FN_REFLEN + 100];
  sprintf(query, "SET SESSION rpl_semi_sync_master_reply_log_file_pos='%llu:%s'",
          (unsigned long long)log_pos, log_name);
  if (mysql_real_query(mysql_reply, query, strlen(query)))
  {
    sql_print_error("Set 'rpl_semi_sync_master_reply_log_file_pos' on master failed");
    mysql_free_result(mysql_store_result(mysql_reply));
    mysql_close(mysql_reply);
    mysql_reply= 0;
    return 1;
  }
  mysql_free_result(mysql_store_result(mysql_reply));
  return 0;
}