log.cc

/* Copyright (C) 2000-2003 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/* logging of commands */
/* TODO: Abort logging when we get an error in reading or writing log files */

#include "mysql_priv.h"
#include "sql_repl.h"
#include "rpl_filter.h"

#include <my_dir.h>
#include <stdarg.h>
#include <m_ctype.h>				// For test_if_number

#ifdef __NT__
#include "message.h"
#endif

#include <mysql/plugin.h>

/*
  Define placement versions of operator new and operator delete since
  we cannot be sure that the <new> include exists.
 */
inline void *operator new(size_t, void *ptr) { return ptr; }
inline void *operator new[](size_t, void *ptr) { return ptr; }
inline void  operator delete(void*, void*) { /* Do nothing */ }
inline void  operator delete[](void*, void*) { /* Do nothing */ }

/* max size of the log message */
#define MAX_LOG_BUFFER_SIZE 1024
#define MAX_USER_HOST_SIZE 512
#define MAX_TIME_SIZE 32
#define MY_OFF_T_UNDEF (~(my_off_t)0UL)

#define FLAGSTR(V,F) ((V)&(F)?#F" ":"")

LOGGER logger;

MYSQL_BIN_LOG mysql_bin_log;
ulong sync_binlog_counter= 0;

static Muted_query_log_event invisible_commit;

static bool test_if_number(const char *str,
			   long *res, bool allow_wildcards);
static int binlog_init(void *p);
static int binlog_close_connection(handlerton *hton, THD *thd);
static int binlog_savepoint_set(handlerton *hton, THD *thd, void *sv);
static int binlog_savepoint_rollback(handlerton *hton, THD *thd, void *sv);
static int binlog_commit(handlerton *hton, THD *thd, bool all);
static int binlog_rollback(handlerton *hton, THD *thd, bool all);
static int binlog_prepare(handlerton *hton, THD *thd, bool all);

sql_print_message_func sql_print_message_handlers[3] =
{
  sql_print_information,
  sql_print_warning,
  sql_print_error
};


char *make_default_log_name(char *buff,const char* log_ext)
{
  strmake(buff, pidfile_name, FN_REFLEN-5);
  return fn_format(buff, buff, mysql_data_home, log_ext,
                   MYF(MY_UNPACK_FILENAME|MY_APPEND_EXT));
}

/*
  Helper class to hold a mutex for the duration of the
  block.

  Eliminates the need for explicit unlocking of mutexes on, e.g.,
  error returns.  On passing a null pointer, the sentry will not do
  anything.
 */
class Mutex_sentry
{
public:
  Mutex_sentry(pthread_mutex_t *mutex)
    : m_mutex(mutex)
  {
    if (m_mutex)
      pthread_mutex_lock(mutex);
  }

  ~Mutex_sentry()
  {
    if (m_mutex)
      pthread_mutex_unlock(m_mutex);
#ifndef DBUG_OFF
    m_mutex= 0;
#endif
  }

private:
  pthread_mutex_t *m_mutex;

  // It's not allowed to copy this object in any way
  Mutex_sentry(Mutex_sentry const&);
  void operator=(Mutex_sentry const&);
};

/*
  Helper class to store binary log transaction data.
*/
class binlog_trx_data {
public:
  binlog_trx_data()
    : m_pending(0), before_stmt_pos(MY_OFF_T_UNDEF)
  {
    trans_log.end_of_file= max_binlog_cache_size;
  }

  ~binlog_trx_data()
  {
    DBUG_ASSERT(pending() == NULL);
    close_cached_file(&trans_log);
  }

  my_off_t position() const {
    return my_b_tell(&trans_log);
  }

  bool empty() const
  {
    return pending() == NULL && my_b_tell(&trans_log) == 0;
  }

  /*
    Truncate the transaction cache to a certain position. This
    includes deleting the pending event.
   */
  void truncate(my_off_t pos)
  {
    DBUG_PRINT("info", ("truncating to position %lu", (ulong) pos));
    delete pending();
    set_pending(0);
    reinit_io_cache(&trans_log, WRITE_CACHE, pos, 0, 0);
    if (pos < before_stmt_pos)
      before_stmt_pos= MY_OFF_T_UNDEF;
  }

  /*
    Reset the entire contents of the transaction cache, emptying it
    completely.
   */
  void reset() {
    if (!empty())
      truncate(0);
    before_stmt_pos= MY_OFF_T_UNDEF;
    trans_log.end_of_file= max_binlog_cache_size;
  }

  Rows_log_event *pending() const
  {
    return m_pending;
  }

  void set_pending(Rows_log_event *const pending)
  {
    m_pending= pending;
  }

  IO_CACHE trans_log;                         // The transaction cache

private:
  /*
    Pending binrows event. This event is the event where the rows are
    currently written.
   */
  Rows_log_event *m_pending;

public:
  /*
    Binlog position before the start of the current statement.
  */
  my_off_t before_stmt_pos;
};

handlerton *binlog_hton;


/* Check if a given table is opened log table */
int check_if_log_table(uint db_len, const char *db, uint table_name_len,
                       const char *table_name, uint check_if_opened)
{
  if (db_len == 5 &&
      !(lower_case_table_names ?
        my_strcasecmp(system_charset_info, db, "mysql") :
        strcmp(db, "mysql")))
  {
    if (table_name_len == 11 && !(lower_case_table_names ?
                                  my_strcasecmp(system_charset_info,
                                                table_name, "general_log") :
                                  strcmp(table_name, "general_log")) &&
        (!check_if_opened || logger.is_log_table_enabled(QUERY_LOG_GENERAL)))
      return QUERY_LOG_GENERAL;
    else
      if (table_name_len == 8 && !(lower_case_table_names ?
        my_strcasecmp(system_charset_info, table_name, "slow_log") :
        strcmp(table_name, "slow_log")) &&
          (!check_if_opened ||logger.is_log_table_enabled(QUERY_LOG_SLOW)))
        return QUERY_LOG_SLOW;
  }
  return 0;
}


/*
  Open log table of a given type (general or slow log)

  SYNOPSIS
    open_log_table()

    log_table_type   type of the log table to open: QUERY_LOG_GENERAL
                     or QUERY_LOG_SLOW

  DESCRIPTION

    The function opens a log table and marks it as such. Log tables are open
    during the whole time, while server is running. Except for the moments
    when they have to be reopened: during FLUSH LOGS and TRUNCATE. This
    function is invoked directly only once during startup. All subsequent
    calls happen through reopen_log_table(), which performs additional check.

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool Log_to_csv_event_handler::open_log_table(uint log_table_type)
{
  THD *log_thd, *curr= current_thd;
  TABLE_LIST *table;
  bool error= FALSE;
  DBUG_ENTER("open_log_table");

  switch (log_table_type) {
  case QUERY_LOG_GENERAL:
    log_thd= general_log_thd;
    table= &general_log;
    /* clean up table before reuse/initial usage */
    bzero((char*) table, sizeof(TABLE_LIST));
    table->alias= table->table_name= (char*) "general_log";
    table->table_name_length= 11;
    break;
  case QUERY_LOG_SLOW:
    log_thd= slow_log_thd;
    table= &slow_log;
    bzero((char*) table, sizeof(TABLE_LIST));
    table->alias= table->table_name= (char*) "slow_log";
    table->table_name_length= 8;
    break;
  default:
    DBUG_ASSERT(0);
  }

  /*
    This way we check that appropriate log thd was created ok during
    initialization. We cannot check "is_log_tables_initialized" var, as
    the very initialization is not finished until this function is
    completed in the very first time.
  */
  if (!log_thd)
  {
    DBUG_PRINT("error",("Cannot initialize log tables"));
    DBUG_RETURN(TRUE);
  }

  /*
    Set THD's thread_stack. This is needed to perform stack overrun
    check, which is done by some routines (e.g. open_table()).
    In the case we are called by thread, which already has this parameter
    set, we use this value. Otherwise we do a wild guess. This won't help
    to correctly track the stack overrun in these exceptional cases (which
    could probably happen only during startup and shutdown) but at least
    lets us to pass asserts.
    The problem stems from the fact that logger THDs are not real threads.
  */
  if (curr)
    log_thd->thread_stack= curr->thread_stack;
  else
    log_thd->thread_stack= (char*) &log_thd;

  log_thd->store_globals();

  table->lock_type= TL_WRITE_CONCURRENT_INSERT;
  table->db= log_thd->db;
  table->db_length= log_thd->db_length;

  if (simple_open_n_lock_tables(log_thd, table) ||
      table->table->file->extra(HA_EXTRA_MARK_AS_LOG_TABLE) ||
      table->table->file->ha_rnd_init(0))
    error= TRUE;
  else
  {
    table->table->use_all_columns();
    table->table->locked_by_logger= TRUE;
  }
  /* restore thread settings */
  if (curr)
    curr->store_globals();
  else
  {
    my_pthread_setspecific_ptr(THR_THD,  0);
    my_pthread_setspecific_ptr(THR_MALLOC, 0);
  }

  /*
    After a log table was opened, we should clear privileged thread
    flag (which allows locking of a log table by a special thread, usually
    the one who closed log tables temporarily).
  */
  privileged_thread= 0;
  DBUG_RETURN(error);
}


Log_to_csv_event_handler::Log_to_csv_event_handler()
{
  /* init artificial THD's */
  general_log_thd= new THD;
  /* logger thread always works with mysql database */
  general_log_thd->db= my_strdup("mysql", MYF(0));
  general_log_thd->db_length= 5;
  general_log.table= 0;

  slow_log_thd= new THD;
  /* logger thread always works with mysql database */
  slow_log_thd->db= my_strdup("mysql", MYF(0));;
  slow_log_thd->db_length= 5;
  slow_log.table= 0;
  /* no privileged thread exists at the moment */
  privileged_thread= 0;
}


Log_to_csv_event_handler::~Log_to_csv_event_handler()
{
  /* now cleanup the tables */
  if (general_log_thd)
  {
    delete general_log_thd;
    general_log_thd= NULL;
  }

  if (slow_log_thd)
  {
    delete slow_log_thd;
    slow_log_thd= NULL;
  }
}


/*
  Reopen log table of a given type

  SYNOPSIS
    reopen_log_table()

    log_table_type   type of the log table to open: QUERY_LOG_GENERAL
                     or QUERY_LOG_SLOW

  DESCRIPTION

    The function is a wrapper around open_log_table(). It is used during
    FLUSH LOGS and TRUNCATE of the log tables (i.e. when we need to close
    and reopen them). The difference is in the check of the
    logger.is_log_tables_initialized var, which can't be done in
    open_log_table(), as it makes no sense during startup.

    NOTE: this code assumes that we have logger mutex locked

  RETURN
    FALSE - ok
    TRUE - open_log_table() returned an error
*/

bool Log_to_csv_event_handler::reopen_log_table(uint log_table_type)
{
  /* don't open the log table, if it wasn't enabled during startup */
  if (!logger.is_log_tables_initialized)
    return FALSE;
  return open_log_table(log_table_type);
}


void Log_to_csv_event_handler::cleanup()
{
  if (opt_log)
    close_log_table(QUERY_LOG_GENERAL, FALSE);
  if (opt_slow_log)
    close_log_table(QUERY_LOG_SLOW, FALSE);
  logger.is_log_tables_initialized= FALSE;
}

/* log event handlers */

/*
  Log command to the general log table

  SYNOPSIS
    log_general()

    event_time        command start timestamp
    user_host         the pointer to the string with user@host info
    user_host_len     length of the user_host string. this is computed once
                      and passed to all general log event handlers
    thread_id         Id of the thread, issued a query
    command_type      the type of the command being logged
    command_type_len  the length of the string above
    sql_text          the very text of the query being executed
    sql_text_len      the length of sql_text string

  DESCRIPTION

   Log given command to the general log table

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool Log_to_csv_event_handler::
  log_general(time_t event_time, const char *user_host,
              uint user_host_len, int thread_id,
              const char *command_type, uint command_type_len,
              const char *sql_text, uint sql_text_len,
              CHARSET_INFO *client_cs)
{
  TABLE *table= general_log.table;

  /*
    "INSERT INTO general_log" can generate warning sometimes.
    Let's reset warnings from previous queries,
    otherwise warning list can grow too much,
    so thd->query gets spoiled as some point in time,
    and mysql_parse() receives a broken query.
    QQ: this problem needs to be studied in more details.
    Probably it's better to suppress warnings in logging INSERTs at all.
    Comment this line and run "cast.test" to see what's happening:
  */
  mysql_reset_errors(table->in_use, 1);

  /* below should never happen */
  if (unlikely(!logger.is_log_tables_initialized))
    return FALSE;

  /*
    NOTE: we do not call restore_record() here, as all fields are
    filled by the Logger (=> no need to load default ones).
  */

  /* Set current time. Required for CURRENT_TIMESTAMP to work */
  general_log_thd->start_time= event_time;

  /*
    We do not set a value for table->field[0], as it will use
    default value (which is CURRENT_TIMESTAMP).
  */

  /* check that all columns exist */
  if (!table->field[1] || !table->field[2] || !table->field[3] ||
      !table->field[4] || !table->field[5])
    goto err;

  /* do a write */
  if (table->field[1]->store(user_host, user_host_len, client_cs) ||
      table->field[2]->store((longlong) thread_id, TRUE) ||
      table->field[3]->store((longlong) server_id, TRUE) ||
      table->field[4]->store(command_type, command_type_len, client_cs) ||
      table->field[5]->store(sql_text, sql_text_len, client_cs))
    goto err;

  /* mark tables as not null */
  table->field[1]->set_notnull();
  table->field[2]->set_notnull();
  table->field[3]->set_notnull();
  table->field[4]->set_notnull();
  table->field[5]->set_notnull();

  /* log table entries are not replicated at the moment */
  tmp_disable_binlog(current_thd);

  table->file->ha_write_row(table->record[0]);

  reenable_binlog(current_thd);

  return FALSE;
err:
  return TRUE;
}


/*
  Log a query to the slow log table

  SYNOPSIS
    log_slow()
    thd               THD of the query
    current_time      current timestamp
    query_start_arg   command start timestamp
    user_host         the pointer to the string with user@host info
    user_host_len     length of the user_host string. this is computed once
                      and passed to all general log event handlers
    query_time        Amount of time the query took to execute (in seconds)
    lock_time         Amount of time the query was locked (in seconds)
    is_command        The flag, which determines, whether the sql_text is a
                      query or an administrator command (these are treated
                      differently by the old logging routines)
    sql_text          the very text of the query or administrator command
                      processed
    sql_text_len      the length of sql_text string

  DESCRIPTION

   Log a query to the slow log table

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool Log_to_csv_event_handler::
  log_slow(THD *thd, time_t current_time, time_t query_start_arg,
           const char *user_host, uint user_host_len,
           longlong query_time, longlong lock_time, bool is_command,
           const char *sql_text, uint sql_text_len)
{
  /* table variables */
  TABLE *table= slow_log.table;
  CHARSET_INFO *client_cs= thd->variables.character_set_client;

  DBUG_ENTER("log_slow");

  /* below should never happen */
  if (unlikely(!logger.is_log_tables_initialized))
    return FALSE;

  /*
     Set start time for CURRENT_TIMESTAMP to the start of the query.
     This will be default value for the field[0]
  */
  slow_log_thd->start_time= query_start_arg;
  restore_record(table, s->default_values);    // Get empty record

  /*
    We do not set a value for table->field[0], as it will use
    default value.
  */

  if (!table->field[1] || !table->field[2] || !table->field[3] ||
      !table->field[4] || !table->field[5] || !table->field[6] ||
      !table->field[7] || !table->field[8] || !table->field[9] ||
      !table->field[10])
    goto err;

  /* store the value */
  if (table->field[1]->store(user_host, user_host_len, client_cs))
    goto err;

  if (query_start_arg)
  {
    /* fill in query_time field */
    if (table->field[2]->store(query_time, TRUE))
      goto err;
    /* lock_time */
    if (table->field[3]->store(lock_time, TRUE))
      goto err;
    /* rows_sent */
    if (table->field[4]->store((longlong) thd->sent_row_count, TRUE))
      goto err;
    /* rows_examined */
    if (table->field[5]->store((longlong) thd->examined_row_count, TRUE))
      goto err;
  }
  else
  {
    table->field[2]->set_null();
    table->field[3]->set_null();
    table->field[4]->set_null();
    table->field[5]->set_null();
  }

  /* fill database field */
  if (thd->db)
  {
    if (table->field[6]->store(thd->db, thd->db_length, client_cs))
      goto err;
    table->field[6]->set_notnull();
  }

  if (thd->stmt_depends_on_first_successful_insert_id_in_prev_stmt)
  {
    if (table->
        field[7]->store((longlong)
                        thd->first_successful_insert_id_in_prev_stmt_for_binlog,
                        TRUE))
      goto err;
    table->field[7]->set_notnull();
  }

  /*
    Set value if we do an insert on autoincrement column. Note that for
    some engines (those for which get_auto_increment() does not leave a
    table lock until the statement ends), this is just the first value and
    the next ones used may not be contiguous to it.
  */
  if (thd->auto_inc_intervals_in_cur_stmt_for_binlog.nb_elements() > 0)
  {
    if (table->
        field[8]->store((longlong)
          thd->auto_inc_intervals_in_cur_stmt_for_binlog.minimum(), TRUE))
      goto err;
    table->field[8]->set_notnull();
  }

  if (table->field[9]->store((longlong) server_id, TRUE))
    goto err;
  table->field[9]->set_notnull();

  /* sql_text */
  if (table->field[10]->store(sql_text,sql_text_len, client_cs))
    goto err;

  /* log table entries are not replicated at the moment */
  tmp_disable_binlog(current_thd);

  /* write the row */
  table->file->ha_write_row(table->record[0]);

  reenable_binlog(current_thd);

  DBUG_RETURN(0);
err:
  DBUG_RETURN(1);
}

bool Log_to_csv_event_handler::
  log_error(enum loglevel level, const char *format, va_list args)
{
  /* No log table is implemented */
  DBUG_ASSERT(0);
  return FALSE;
}

bool Log_to_file_event_handler::
  log_error(enum loglevel level, const char *format,
            va_list args)
{
  return vprint_msg_to_log(level, format, args);
}

void Log_to_file_event_handler::init_pthread_objects()
{
  mysql_log.init_pthread_objects();
  mysql_slow_log.init_pthread_objects();
}


/* Wrapper around MYSQL_LOG::write() for slow log */

bool Log_to_file_event_handler::
  log_slow(THD *thd, time_t current_time, time_t query_start_arg,
           const char *user_host, uint user_host_len,
           longlong query_time, longlong lock_time, bool is_command,
           const char *sql_text, uint sql_text_len)
{
  return mysql_slow_log.write(thd, current_time, query_start_arg,
                              user_host, user_host_len,
                              query_time, lock_time, is_command,
                              sql_text, sql_text_len);
}


/*
   Wrapper around MYSQL_LOG::write() for general log. We need it since we
   want all log event handlers to have the same signature.
*/

bool Log_to_file_event_handler::
  log_general(time_t event_time, const char *user_host,
              uint user_host_len, int thread_id,
              const char *command_type, uint command_type_len,
              const char *sql_text, uint sql_text_len,
              CHARSET_INFO *client_cs)
{
  return mysql_log.write(event_time, user_host, user_host_len,
                         thread_id, command_type, command_type_len,
                         sql_text, sql_text_len);
}


bool Log_to_file_event_handler::init()
{
  if (!is_initialized)
  {
    if (opt_slow_log)
      mysql_slow_log.open_slow_log(sys_var_slow_log_path.value);

    if (opt_log)
      mysql_log.open_query_log(sys_var_general_log_path.value);

    is_initialized= TRUE;
  }

  return FALSE;
}


void Log_to_file_event_handler::cleanup()
{
  mysql_log.cleanup();
  mysql_slow_log.cleanup();
}

void Log_to_file_event_handler::flush()
{
  /* reopen log files */
  if (opt_log)
    mysql_log.reopen_file();
  if (opt_slow_log)
    mysql_slow_log.reopen_file();
}

/*
  Log error with all enabled log event handlers

  SYNOPSIS
    error_log_print()

    level             The level of the error significance: NOTE,
                      WARNING or ERROR.
    format            format string for the error message
    args              list of arguments for the format string

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool LOGGER::error_log_print(enum loglevel level, const char *format,
                             va_list args)
{
  bool error= FALSE;
  Log_event_handler **current_handler= error_log_handler_list;

  /* currently we don't need locking here as there is no error_log table */
  while (*current_handler)
    error= (*current_handler++)->log_error(level, format, args) || error;

  return error;
}


void LOGGER::cleanup_base()
{
  DBUG_ASSERT(inited == 1);
  (void) pthread_mutex_destroy(&LOCK_logger);
  if (table_log_handler)
  {
    table_log_handler->cleanup();
    delete table_log_handler;
  }
  if (file_log_handler)
    file_log_handler->cleanup();
}


void LOGGER::cleanup_end()
{
  DBUG_ASSERT(inited == 1);
  if (file_log_handler)
    delete file_log_handler;
}


void LOGGER::close_log_table(uint log_table_type, bool lock_in_use)
{
  table_log_handler->close_log_table(log_table_type, lock_in_use);
}


/*
  Perform basic log initialization: create file-based log handler and
  init error log.
*/
void LOGGER::init_base()
{
  DBUG_ASSERT(inited == 0);
  inited= 1;

  /*
    Here we create file log handler. We don't do it for the table log handler
    here as it cannot be created so early. The reason is THD initialization,
    which depends on the system variables (parsed later).
  */
  if (!file_log_handler)
    file_log_handler= new Log_to_file_event_handler;

  /* by default we use traditional error log */
  init_error_log(LOG_FILE);

  file_log_handler->init_pthread_objects();
  (void) pthread_mutex_init(&LOCK_logger, MY_MUTEX_INIT_SLOW);
}


void LOGGER::init_log_tables()
{
  if (!table_log_handler)
    table_log_handler= new Log_to_csv_event_handler;

  if (!is_log_tables_initialized &&
      !table_log_handler->init() && !file_log_handler->init())
    is_log_tables_initialized= TRUE;
}


bool LOGGER::reopen_log_table(uint log_table_type)
{
  return table_log_handler->reopen_log_table(log_table_type);
}

bool LOGGER::reopen_log_tables()
{
    /*
      we use | and not || here, to ensure that both reopen_log_table
      are called, even if the first one fails
    */
    if ((opt_slow_log && logger.reopen_log_table(QUERY_LOG_SLOW)) |
        (opt_log && logger.reopen_log_table(QUERY_LOG_GENERAL)))
      return TRUE;
    return FALSE;
}


void LOGGER::tmp_close_log_tables(THD *thd)
{
  table_log_handler->tmp_close_log_tables(thd);
}

bool LOGGER::flush_logs(THD *thd)
{
  int rc= 0;

  /*
    Now we lock logger, as nobody should be able to use logging routines while
    log tables are closed
  */
  logger.lock();
  if (logger.is_log_tables_initialized)
    table_log_handler->tmp_close_log_tables(thd); // the locking happens here

  /* reopen log files */
  file_log_handler->flush();

  /* reopen tables in the case they were enabled */
  if (logger.is_log_tables_initialized)
  {
    if (reopen_log_tables())
      rc= TRUE;
  }
  /* end of log flush */
  logger.unlock();
  return rc;
}


/*
  Log slow query with all enabled log event handlers

  SYNOPSIS
    slow_log_print()

    thd               THD of the query being logged
    query             The query being logged
    query_length      The length of the query string
    query_start_arg   Query start timestamp

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool LOGGER::slow_log_print(THD *thd, const char *query, uint query_length,
                            time_t query_start_arg)
{
  bool error= FALSE;
  Log_event_handler **current_handler= slow_log_handler_list;
  bool is_command= FALSE;
  char user_host_buff[MAX_USER_HOST_SIZE];

  my_time_t current_time;
  Security_context *sctx= thd->security_ctx;
  uint user_host_len= 0;
  longlong query_time= 0, lock_time= 0;

  /*
    Print the message to the buffer if we have slow log enabled
  */

  if (*slow_log_handler_list)
  {
    current_time= time(NULL);

    /* do not log slow queries from replication threads */
    if (thd->slave_thread)
      return 0;

    lock();
    if (!opt_slow_log)
    {
      unlock();
      return 0;
    }

    /* fill in user_host value: the format is "%s[%s] @ %s [%s]" */
    user_host_len= strxnmov(user_host_buff, MAX_USER_HOST_SIZE,
                            sctx->priv_user ? sctx->priv_user : "", "[",
                            sctx->user ? sctx->user : "", "] @ ",
                            sctx->host ? sctx->host : "", " [",
                            sctx->ip ? sctx->ip : "", "]", NullS) -
      user_host_buff;

    if (query_start_arg)
    {
      query_time= (longlong) (current_time - query_start_arg);
      lock_time= (longlong) (thd->time_after_lock - query_start_arg);
    }

    if (!query)
    {
      is_command= TRUE;
      query= command_name[thd->command].str;
      query_length= command_name[thd->command].length;
    }

    while (*current_handler)
      error= (*current_handler++)->log_slow(thd, current_time, query_start_arg,
                                            user_host_buff, user_host_len,
                                            query_time, lock_time, is_command,
                                            query, query_length) || error;

    unlock();
  }
  return error;
}

bool LOGGER::general_log_print(THD *thd, enum enum_server_command command,
                               const char *format, va_list args)
{
  bool error= FALSE;
  Log_event_handler **current_handler= general_log_handler_list;

  /*
    Print the message to the buffer if we have at least one log event handler
    enabled and want to log this king of commands
  */
  if (*general_log_handler_list && (what_to_log & (1L << (uint) command)))
  {
    char message_buff[MAX_LOG_BUFFER_SIZE];
    char user_host_buff[MAX_USER_HOST_SIZE];
    Security_context *sctx= thd->security_ctx;
    ulong id;
    uint message_buff_len= 0, user_host_len= 0;

    if (thd)
    {                                           /* Normal thread */
      if ((thd->options & OPTION_LOG_OFF)
#ifndef NO_EMBEDDED_ACCESS_CHECKS
          && (sctx->master_access & SUPER_ACL)
#endif
         )
      {
        return 0;                         /* No logging */
      }
      id= thd->thread_id;
    }
    else
      id=0;                                     /* Log from connect handler */

    lock();
    if (!opt_log)
    {
      unlock();
      return 0;
    }
    time_t current_time= time(NULL);

    user_host_len= strxnmov(user_host_buff, MAX_USER_HOST_SIZE,
                            sctx->priv_user ? sctx->priv_user : "", "[",
                            sctx->user ? sctx->user : "", "] @ ",
                            sctx->host ? sctx->host : "", " [",
                            sctx->ip ? sctx->ip : "", "]", NullS) -
                                                            user_host_buff;

    /* prepare message */
    if (format)
      message_buff_len= my_vsnprintf(message_buff,
                   sizeof(message_buff), format, args);
    else
      message_buff[0]= '\0';

    while (*current_handler)
      error+= (*current_handler++)->
        log_general(current_time, user_host_buff,
                   user_host_len, id,
                   command_name[(uint) command].str,
                   command_name[(uint) command].length,
                   message_buff, message_buff_len,
                   thd->variables.character_set_client) || error;
    unlock();
  }
  return error;
}

void LOGGER::init_error_log(uint error_log_printer)
{
  if (error_log_printer & LOG_NONE)
  {
    error_log_handler_list[0]= 0;
    return;
  }

  switch (error_log_printer) {
  case LOG_FILE:
    error_log_handler_list[0]= file_log_handler;
    error_log_handler_list[1]= 0;
    break;
    /* these two are disabled for now */
  case LOG_TABLE:
    DBUG_ASSERT(0);
    break;
  case LOG_TABLE|LOG_FILE:
    DBUG_ASSERT(0);
    break;
  }
}

void LOGGER::init_slow_log(uint slow_log_printer)
{
  if (slow_log_printer & LOG_NONE)
  {
    slow_log_handler_list[0]= 0;
    return;
  }

  switch (slow_log_printer) {
  case LOG_FILE:
    slow_log_handler_list[0]= file_log_handler;
    slow_log_handler_list[1]= 0;
    break;
  case LOG_TABLE:
    slow_log_handler_list[0]= table_log_handler;
    slow_log_handler_list[1]= 0;
    break;
  case LOG_TABLE|LOG_FILE:
    slow_log_handler_list[0]= file_log_handler;
    slow_log_handler_list[1]= table_log_handler;
    slow_log_handler_list[2]= 0;
    break;
  }
}

void LOGGER::init_general_log(uint general_log_printer)
{
  if (general_log_printer & LOG_NONE)
  {
    general_log_handler_list[0]= 0;
    return;
  }

  switch (general_log_printer) {
  case LOG_FILE:
    general_log_handler_list[0]= file_log_handler;
    general_log_handler_list[1]= 0;
    break;
  case LOG_TABLE:
    general_log_handler_list[0]= table_log_handler;
    general_log_handler_list[1]= 0;
    break;
  case LOG_TABLE|LOG_FILE:
    general_log_handler_list[0]= file_log_handler;
    general_log_handler_list[1]= table_log_handler;
    general_log_handler_list[2]= 0;
    break;
  }
}


bool LOGGER::activate_log_handler(THD* thd, uint log_type)
{
  bool res= 0;
  lock();
  switch (log_type) {
  case QUERY_LOG_SLOW:
    if (!opt_slow_log)
    {
      if ((res= reopen_log_table(log_type)))
        goto err;
      file_log_handler->get_mysql_slow_log()->
        open_slow_log(sys_var_slow_log_path.value);
      init_slow_log(log_output_options);
      opt_slow_log= TRUE;
    }
    break;
  case QUERY_LOG_GENERAL:
    if (!opt_log)
    {
      if ((res= reopen_log_table(log_type)))
        goto err;
      file_log_handler->get_mysql_log()->
        open_query_log(sys_var_general_log_path.value);
      init_general_log(log_output_options);
      opt_log= TRUE;
    }
    break;
  default:
    DBUG_ASSERT(0);
  }
err:
  unlock();
  return res;
}


void LOGGER::deactivate_log_handler(THD *thd, uint log_type)
{
  TABLE_LIST *table_list;
  my_bool *tmp_opt= 0;
  MYSQL_LOG *file_log;
  THD *log_thd;

  switch (log_type) {
  case QUERY_LOG_SLOW:
    table_list= &table_log_handler->slow_log;
    tmp_opt= &opt_slow_log;
    file_log= file_log_handler->get_mysql_slow_log();
    log_thd= table_log_handler->slow_log_thd;
    break;
  case QUERY_LOG_GENERAL:
    table_list= &table_log_handler->general_log;
    tmp_opt= &opt_log;
    file_log= file_log_handler->get_mysql_log();
    log_thd= table_log_handler->general_log_thd;
    break;
  default:
    DBUG_ASSERT(0);
  }

  if (!(*tmp_opt))
    return;

  if (is_log_tables_initialized)
    lock_and_wait_for_table_name(log_thd, table_list);
  lock();

  if (is_log_tables_initialized)
  {
    VOID(pthread_mutex_lock(&LOCK_open));
    close_log_table(log_type, TRUE);
    table_list->table= 0;
    query_cache_invalidate3(log_thd, table_list, 0);
    unlock_table_name(log_thd, table_list);
    VOID(pthread_mutex_unlock(&LOCK_open));
  }
  file_log->close(0);
  *tmp_opt= FALSE;
  unlock();
}


/*
  Close log tables temporarily. The thread which closed
  them this way can lock them in any mode it needs.
  NOTE: one should call logger.lock() before entering this
  function.
*/
void Log_to_csv_event_handler::tmp_close_log_tables(THD *thd)
{
  TABLE_LIST close_slow_log, close_general_log;

  /* fill lists, we will need to perform operations on tables */
  bzero((char*) &close_slow_log, sizeof(TABLE_LIST));
  close_slow_log.alias= close_slow_log.table_name=(char*) "slow_log";
  close_slow_log.table_name_length= 8;
  close_slow_log.db= (char*) "mysql";
  close_slow_log.db_length= 5;

  bzero((char*) &close_general_log, sizeof(TABLE_LIST));
  close_general_log.alias= close_general_log.table_name=(char*) "general_log";
  close_general_log.table_name_length= 11;
  close_general_log.db= (char*) "mysql";
  close_general_log.db_length= 5;

  privileged_thread= thd;

  VOID(pthread_mutex_lock(&LOCK_open));
  /*
    NOTE: in fact, the first parameter used in query_cache_invalidate3()
    could be any non-NULL THD, as the underlying code makes certain
    assumptions about this.
    Here we use one of the logger handler THD's. Simply because it
    seems appropriate.
  */
  if (opt_log)
  {
    close_log_table(QUERY_LOG_GENERAL, TRUE);
    query_cache_invalidate3(general_log_thd, &close_general_log, 0);
  }
  if (opt_slow_log)
  {
    close_log_table(QUERY_LOG_SLOW, TRUE);
    query_cache_invalidate3(general_log_thd, &close_slow_log, 0);
  }
  VOID(pthread_mutex_unlock(&LOCK_open));
}

/* the parameters are unused for the log tables */
bool Log_to_csv_event_handler::init()
{
  /*
    we use | and not || here, to ensure that both open_log_table
    are called, even if the first one fails
  */
  if ((opt_log && open_log_table(QUERY_LOG_GENERAL)) |
      (opt_slow_log && open_log_table(QUERY_LOG_SLOW)))
    return 1;
  return 0;
}

int LOGGER::set_handlers(uint error_log_printer,
                         uint slow_log_printer,
                         uint general_log_printer)
{
  /* error log table is not supported yet */
  DBUG_ASSERT(error_log_printer < LOG_TABLE);

  lock();

  if ((slow_log_printer & LOG_TABLE || general_log_printer & LOG_TABLE) &&
      !is_log_tables_initialized)
  {
    slow_log_printer= (slow_log_printer & ~LOG_TABLE) | LOG_FILE;
    general_log_printer= (general_log_printer & ~LOG_TABLE) | LOG_FILE;

    sql_print_error("Failed to initialize log tables. "
                    "Falling back to the old-fashioned logs");
  }

  init_error_log(error_log_printer);
  init_slow_log(slow_log_printer);
  init_general_log(general_log_printer);

  unlock();

  return 0;
}


/*
  Close log table of a given type (general or slow log)

  SYNOPSIS
    close_log_table()

    log_table_type   type of the log table to close: QUERY_LOG_GENERAL
                     or QUERY_LOG_SLOW
    lock_in_use      Set to TRUE if the caller owns LOCK_open. FALSE otherwise.

  DESCRIPTION

    The function closes a log table. It is invoked (1) when we need to reopen
    log tables (e.g. FLUSH LOGS or TRUNCATE on the log table is being
    executed) or (2) during shutdown.
*/

void Log_to_csv_event_handler::
  close_log_table(uint log_table_type, bool lock_in_use)
{
  THD *log_thd, *curr= current_thd;
  TABLE_LIST *table;

  if (!logger.is_log_table_enabled(log_table_type))
    return;                                     /* do nothing */

  switch (log_table_type) {
  case QUERY_LOG_GENERAL:
    log_thd= general_log_thd;
    table= &general_log;
    break;
  case QUERY_LOG_SLOW:
    log_thd= slow_log_thd;
    table= &slow_log;
    break;
  default:
    DBUG_ASSERT(0);
  }

  /*
    Set thread stack start for the logger thread. See comment in
    open_log_table() for details.
  */
  if (curr)
    log_thd->thread_stack= curr->thread_stack;
  else
    log_thd->thread_stack= (char*) &log_thd;

  /* close the table */
  log_thd->store_globals();
  table->table->file->ha_rnd_end();
  /* discard logger mark before unlock*/
  table->table->locked_by_logger= FALSE;
  close_thread_tables(log_thd, lock_in_use);

  if (curr)
    curr->store_globals();
  else
  {
    my_pthread_setspecific_ptr(THR_THD,  0);
    my_pthread_setspecific_ptr(THR_MALLOC, 0);
  }
}


 /*
  Save position of binary log transaction cache.

  SYNPOSIS
    binlog_trans_log_savepos()

    thd      The thread to take the binlog data from
    pos      Pointer to variable where the position will be stored

  DESCRIPTION

    Save the current position in the binary log transaction cache into
    the variable pointed to by 'pos'
 */

static void
binlog_trans_log_savepos(THD *thd, my_off_t *pos)
{
  DBUG_ENTER("binlog_trans_log_savepos");
  DBUG_ASSERT(pos != NULL);
  if (thd->ha_data[binlog_hton->slot] == NULL)
    thd->binlog_setup_trx_data();
  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  DBUG_ASSERT(mysql_bin_log.is_open());
  *pos= trx_data->position();
  DBUG_PRINT("return", ("*pos: %lu", (ulong) *pos));
  DBUG_VOID_RETURN;
}


/*
  Truncate the binary log transaction cache.

  SYNPOSIS
    binlog_trans_log_truncate()

    thd      The thread to take the binlog data from
    pos      Position to truncate to

  DESCRIPTION

    Truncate the binary log to the given position. Will not change
    anything else.

 */
static void
binlog_trans_log_truncate(THD *thd, my_off_t pos)
{
  DBUG_ENTER("binlog_trans_log_truncate");
  DBUG_PRINT("enter", ("pos: %lu", (ulong) pos));

  DBUG_ASSERT(thd->ha_data[binlog_hton->slot] != NULL);
  /* Only true if binlog_trans_log_savepos() wasn't called before */
  DBUG_ASSERT(pos != ~(my_off_t) 0);

  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  trx_data->truncate(pos);
  DBUG_VOID_RETURN;
}


/*
  this function is mostly a placeholder.
  conceptually, binlog initialization (now mostly done in MYSQL_BIN_LOG::open)
  should be moved here.
*/

int binlog_init(void *p)
{
  binlog_hton= (handlerton *)p;
  binlog_hton->state=opt_bin_log ? SHOW_OPTION_YES : SHOW_OPTION_NO;
  binlog_hton->db_type=DB_TYPE_BINLOG;
  binlog_hton->savepoint_offset= sizeof(my_off_t);
  binlog_hton->close_connection= binlog_close_connection;
  binlog_hton->savepoint_set= binlog_savepoint_set;
  binlog_hton->savepoint_rollback= binlog_savepoint_rollback;
  binlog_hton->commit= binlog_commit;
  binlog_hton->rollback= binlog_rollback;
  binlog_hton->prepare= binlog_prepare;
  binlog_hton->flags= HTON_NOT_USER_SELECTABLE | HTON_HIDDEN;
  return 0;
}

static int binlog_close_connection(handlerton *hton, THD *thd)
{
  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  DBUG_ASSERT(mysql_bin_log.is_open() && trx_data->empty());
  thd->ha_data[binlog_hton->slot]= 0;
  trx_data->~binlog_trx_data();
  my_free((gptr)trx_data, MYF(0));
  return 0;
}

/*
  End a transaction.

  SYNOPSIS
    binlog_end_trans()

    thd      The thread whose transaction should be ended
    trx_data Pointer to the transaction data to use
    end_ev   The end event to use, or NULL
    all      True if the entire transaction should be ended, false if
             only the statement transaction should be ended.

  DESCRIPTION

    End the currently open transaction. The transaction can be either
    a real transaction (if 'all' is true) or a statement transaction
    (if 'all' is false).

    If 'end_ev' is NULL, the transaction is a rollback of only
    transactional tables, so the transaction cache will be truncated
    to either just before the last opened statement transaction (if
    'all' is false), or reset completely (if 'all' is true).
 */
static int
binlog_end_trans(THD *thd, binlog_trx_data *trx_data,
                 Log_event *end_ev, bool all)
{
  DBUG_ENTER("binlog_end_trans");
  int error=0;
  IO_CACHE *trans_log= &trx_data->trans_log;
  DBUG_PRINT("enter", ("transaction: %s  end_ev: 0x%lx",
                       all ? "all" : "stmt", (long) end_ev));
  DBUG_PRINT("info", ("thd->options={ %s%s}",
                      FLAGSTR(thd->options, OPTION_NOT_AUTOCOMMIT),
                      FLAGSTR(thd->options, OPTION_BEGIN)));

  /*
    NULL denotes ROLLBACK with nothing to replicate: i.e., rollback of
    only transactional tables.  If the transaction contain changes to
    any non-transactiona tables, we need write the transaction and log
    a ROLLBACK last.
  */
  if (end_ev != NULL)
  {
    /*
      Doing a commit or a rollback including non-transactional tables,
      i.e., ending a transaction where we might write the transaction
      cache to the binary log.

      We can always end the statement when ending a transaction since
      transactions are not allowed inside stored functions.  If they
      were, we would have to ensure that we're not ending a statement
      inside a stored function.
     */
    thd->binlog_flush_pending_rows_event(TRUE);
    /*
      We write the transaction cache to the binary log if either we're
      committing the entire transaction, or if we are doing an
      autocommit outside a transaction.
     */
    if (all || !(thd->options & (OPTION_BEGIN | OPTION_NOT_AUTOCOMMIT)))
    {
      error= mysql_bin_log.write(thd, &trx_data->trans_log, end_ev);
      trx_data->reset();
      /*
        We need to step the table map version after writing the
        transaction cache to disk.
      */
      mysql_bin_log.update_table_map_version();
      statistic_increment(binlog_cache_use, &LOCK_status);
      if (trans_log->disk_writes != 0)
      {
        statistic_increment(binlog_cache_disk_use, &LOCK_status);
        trans_log->disk_writes= 0;
      }
    }
  }
  else
  {
    /*
      If rolling back an entire transaction or a single statement not
      inside a transaction, we reset the transaction cache.

      If rolling back a statement in a transaction, we truncate the
      transaction cache to remove the statement.
     */
    if (all || !(thd->options & (OPTION_BEGIN | OPTION_NOT_AUTOCOMMIT)))
      trx_data->reset();
    else                                        // ...statement
      trx_data->truncate(trx_data->before_stmt_pos);

    /*
      We need to step the table map version on a rollback to ensure
      that a new table map event is generated instead of the one that
      was written to the thrown-away transaction cache.
    */
    mysql_bin_log.update_table_map_version();
  }

  DBUG_RETURN(error);
}

static int binlog_prepare(handlerton *hton, THD *thd, bool all)
{
  /*
    do nothing.
    just pretend we can do 2pc, so that MySQL won't
    switch to 1pc.
    real work will be done in MYSQL_BIN_LOG::log_xid()
  */
  return 0;
}

static int binlog_commit(handlerton *hton, THD *thd, bool all)
{
  DBUG_ENTER("binlog_commit");
  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  DBUG_ASSERT(mysql_bin_log.is_open());

  if (all && trx_data->empty())
  {
    // we're here because trans_log was flushed in MYSQL_BIN_LOG::log_xid()
    trx_data->reset();
    DBUG_RETURN(0);
  }
  if (all)
  {
    Query_log_event qev(thd, STRING_WITH_LEN("COMMIT"), TRUE, FALSE);
    qev.error_code= 0; // see comment in MYSQL_LOG::write(THD, IO_CACHE)
    int error= binlog_end_trans(thd, trx_data, &qev, all);
    DBUG_RETURN(error);
  }
  else
  {
    int error= binlog_end_trans(thd, trx_data, &invisible_commit, all);
    DBUG_RETURN(error);
  }
}

static int binlog_rollback(handlerton *hton, THD *thd, bool all)
{
  DBUG_ENTER("binlog_rollback");
  int error=0;
  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  DBUG_ASSERT(mysql_bin_log.is_open());

  if (trx_data->empty()) {
    trx_data->reset();
    DBUG_RETURN(0);
  }

  /*
    Update the binary log with a BEGIN/ROLLBACK block if we have
    cached some queries and we updated some non-transactional
    table. Such cases should be rare (updating a
    non-transactional table inside a transaction...)
  */
  if (unlikely(thd->options & (OPTION_STATUS_NO_TRANS_UPDATE |
                               OPTION_KEEP_LOG)))
  {
    Query_log_event qev(thd, STRING_WITH_LEN("ROLLBACK"), TRUE, FALSE);
    qev.error_code= 0; // see comment in MYSQL_LOG::write(THD, IO_CACHE)
    error= binlog_end_trans(thd, trx_data, &qev, all);
  }
  else
    error= binlog_end_trans(thd, trx_data, 0, all);
  DBUG_RETURN(error);
}

/*
  NOTE: how do we handle this (unlikely but legal) case:
  [transaction] + [update to non-trans table] + [rollback to savepoint] ?
  The problem occurs when a savepoint is before the update to the
  non-transactional table. Then when there's a rollback to the savepoint, if we
  simply truncate the binlog cache, we lose the part of the binlog cache where
  the update is. If we want to not lose it, we need to write the SAVEPOINT
  command and the ROLLBACK TO SAVEPOINT command to the binlog cache. The latter
  is easy: it's just write at the end of the binlog cache, but the former
  should be *inserted* to the place where the user called SAVEPOINT. The
  solution is that when the user calls SAVEPOINT, we write it to the binlog
  cache (so no need to later insert it). As transactions are never intermixed
  in the binary log (i.e. they are serialized), we won't have conflicts with
  savepoint names when using mysqlbinlog or in the slave SQL thread.
  Then when ROLLBACK TO SAVEPOINT is called, if we updated some
  non-transactional table, we don't truncate the binlog cache but instead write
  ROLLBACK TO SAVEPOINT to it; otherwise we truncate the binlog cache (which
  will chop the SAVEPOINT command from the binlog cache, which is good as in
  that case there is no need to have it in the binlog).
*/

static int binlog_savepoint_set(handlerton *hton, THD *thd, void *sv)
{
  DBUG_ENTER("binlog_savepoint_set");

  binlog_trans_log_savepos(thd, (my_off_t*) sv);
  /* Write it to the binary log */
  
  int const error=
    thd->binlog_query(THD::STMT_QUERY_TYPE,
                      thd->query, thd->query_length, TRUE, FALSE);
  DBUG_RETURN(error);
}

static int binlog_savepoint_rollback(handlerton *hton, THD *thd, void *sv)
{
  DBUG_ENTER("binlog_savepoint_rollback");
  DBUG_ASSERT(mysql_bin_log.is_open());

  /*
    Write ROLLBACK TO SAVEPOINT to the binlog cache if we have updated some
    non-transactional table. Otherwise, truncate the binlog cache starting
    from the SAVEPOINT command.
  */
  if (unlikely(thd->options &
               (OPTION_STATUS_NO_TRANS_UPDATE | OPTION_KEEP_LOG)))
  {
    int error=
      thd->binlog_query(THD::STMT_QUERY_TYPE,
                        thd->query, thd->query_length, TRUE, FALSE);
    DBUG_RETURN(error);
  }
  binlog_trans_log_truncate(thd, *(my_off_t*)sv);
  DBUG_RETURN(0);
}


int check_binlog_magic(IO_CACHE* log, const char** errmsg)
{
  char magic[4];
  DBUG_ASSERT(my_b_tell(log) == 0);

  if (my_b_read(log, (byte*) magic, sizeof(magic)))
  {
    *errmsg = "I/O error reading the header from the binary log";
    sql_print_error("%s, errno=%d, io cache code=%d", *errmsg, my_errno,
		    log->error);
    return 1;
  }
  if (memcmp(magic, BINLOG_MAGIC, sizeof(magic)))
  {
    *errmsg = "Binlog has bad magic number;  It's not a binary log file that can be used by this version of MySQL";
    return 1;
  }
  return 0;
}


File open_binlog(IO_CACHE *log, const char *log_file_name, const char **errmsg)
{
  File file;
  DBUG_ENTER("open_binlog");

  if ((file = my_open(log_file_name, O_RDONLY | O_BINARY | O_SHARE, 
                      MYF(MY_WME))) < 0)
  {
    sql_print_error("Failed to open log (file '%s', errno %d)",
                    log_file_name, my_errno);
    *errmsg = "Could not open log file";
    goto err;
  }
  if (init_io_cache(log, file, IO_SIZE*2, READ_CACHE, 0, 0,
                    MYF(MY_WME|MY_DONT_CHECK_FILESIZE)))
  {
    sql_print_error("Failed to create a cache on log (file '%s')",
                    log_file_name);
    *errmsg = "Could not open log file";
    goto err;
  }
  if (check_binlog_magic(log,errmsg))
    goto err;
  DBUG_RETURN(file);

err:
  if (file >= 0)
  {
    my_close(file,MYF(0));
    end_io_cache(log);
  }
  DBUG_RETURN(-1);
}

#ifdef __NT__
static int eventSource = 0;

void setup_windows_event_source()
{
  HKEY    hRegKey= NULL;
  DWORD   dwError= 0;
  TCHAR   szPath[MAX_PATH];
  DWORD dwTypes;

  if (eventSource)               // Ensure that we are only called once
    return;
  eventSource= 1;

  // Create the event source registry key
  dwError= RegCreateKey(HKEY_LOCAL_MACHINE,
                          "SYSTEM\\CurrentControlSet\\Services\\EventLog\\Application\\MySQL", 
                          &hRegKey);

  /* Name of the PE module that contains the message resource */
  GetModuleFileName(NULL, szPath, MAX_PATH);

  /* Register EventMessageFile */
  dwError = RegSetValueEx(hRegKey, "EventMessageFile", 0, REG_EXPAND_SZ,
                          (PBYTE) szPath, strlen(szPath)+1);

  /* Register supported event types */
  dwTypes= (EVENTLOG_ERROR_TYPE | EVENTLOG_WARNING_TYPE |
            EVENTLOG_INFORMATION_TYPE);
  dwError= RegSetValueEx(hRegKey, "TypesSupported", 0, REG_DWORD,
                         (LPBYTE) &dwTypes, sizeof dwTypes);

  RegCloseKey(hRegKey);
}

#endif /* __NT__ */


/****************************************************************************
** Find a uniq filename for 'filename.#'.
** Set # to a number as low as possible
** returns != 0 if not possible to get uniq filename
****************************************************************************/

static int find_uniq_filename(char *name)
{
  long                  number;
  uint                  i;
  char                  buff[FN_REFLEN];
  struct st_my_dir     *dir_info;
  reg1 struct fileinfo *file_info;
  ulong                 max_found=0;

  DBUG_ENTER("find_uniq_filename");

  uint  length = dirname_part(buff,name);
  char *start  = name + length;
  char *end    = strend(start);

  *end='.';
  length= (uint) (end-start+1);

  if (!(dir_info = my_dir(buff,MYF(MY_DONT_SORT))))
  {						// This shouldn't happen
    strmov(end,".1");				// use name+1
    DBUG_RETURN(0);
  }
  file_info= dir_info->dir_entry;
  for (i=dir_info->number_off_files ; i-- ; file_info++)
  {
    if (bcmp(file_info->name,start,length) == 0 &&
	test_if_number(file_info->name+length, &number,0))
    {
      set_if_bigger(max_found,(ulong) number);
    }
  }
  my_dirend(dir_info);

  *end++='.';
  sprintf(end,"%06ld",max_found+1);
  DBUG_RETURN(0);
}


void MYSQL_LOG::init(enum_log_type log_type_arg,
                     enum cache_type io_cache_type_arg)
{
  DBUG_ENTER("MYSQL_LOG::init");
  log_type= log_type_arg;
  io_cache_type= io_cache_type_arg;
  DBUG_PRINT("info",("log_type: %d", log_type));
  DBUG_VOID_RETURN;
}


/*
  Open a (new) log file.

  SYNOPSIS
    open()

    log_name            The name of the log to open
    log_type_arg        The type of the log. E.g. LOG_NORMAL
    new_name            The new name for the logfile. This is only needed
                        when the method is used to open the binlog file.
    io_cache_type_arg   The type of the IO_CACHE to use for this log file

  DESCRIPTION
    Open the logfile, init IO_CACHE and write startup messages
    (in case of general and slow query logs).

  RETURN VALUES
    0   ok
    1   error
*/

bool MYSQL_LOG::open(const char *log_name, enum_log_type log_type_arg,
                     const char *new_name, enum cache_type io_cache_type_arg)
{
  char buff[FN_REFLEN];
  File file= -1;
  int open_flags= O_CREAT | O_BINARY;
  DBUG_ENTER("MYSQL_LOG::open");
  DBUG_PRINT("enter", ("log_type: %d", (int) log_type_arg));

  write_error= 0;

  init(log_type_arg, io_cache_type_arg);

  if (!(name= my_strdup(log_name, MYF(MY_WME))))
  {
    name= (char *)log_name; // for the error message
    goto err;
  }

  if (new_name)
    strmov(log_file_name, new_name);
  else if (generate_new_name(log_file_name, name))
    goto err;

  if (io_cache_type == SEQ_READ_APPEND)
    open_flags |= O_RDWR | O_APPEND;
  else
    open_flags |= O_WRONLY | (log_type == LOG_BIN ? 0 : O_APPEND);

  db[0]= 0;

  if ((file= my_open(log_file_name, open_flags,
                     MYF(MY_WME | ME_WAITTANG))) < 0 ||
      init_io_cache(&log_file, file, IO_SIZE, io_cache_type,
                    my_tell(file, MYF(MY_WME)), 0,
                    MYF(MY_WME | MY_NABP |
                        ((log_type == LOG_BIN) ? MY_WAIT_IF_FULL : 0))))
    goto err;

  if (log_type == LOG_NORMAL)
  {
    char *end;
    int len=my_snprintf(buff, sizeof(buff), "%s, Version: %s (%s). "
#ifdef EMBEDDED_LIBRARY
                        "embedded library\n",
                        my_progname, server_version, MYSQL_COMPILATION_COMMENT
#elif __NT__
			"started with:\nTCP Port: %d, Named Pipe: %s\n",
                        my_progname, server_version, MYSQL_COMPILATION_COMMENT,
                        mysqld_port, mysqld_unix_port
#else
			"started with:\nTcp port: %d  Unix socket: %s\n",
                        my_progname, server_version, MYSQL_COMPILATION_COMMENT,
                        mysqld_port, mysqld_unix_port
#endif
                       );
    end= strnmov(buff + len, "Time                 Id Command    Argument\n",
                 sizeof(buff) - len);
    if (my_b_write(&log_file, (byte*) buff, (uint) (end-buff)) ||
	flush_io_cache(&log_file))
      goto err;
  }

  log_state= LOG_OPENED;
  DBUG_RETURN(0);

err:
  sql_print_error("Could not use %s for logging (error %d). \
Turning logging off for the whole duration of the MySQL server process. \
To turn it on again: fix the cause, \
shutdown the MySQL server and restart it.", name, errno);
  if (file >= 0)
    my_close(file, MYF(0));
  end_io_cache(&log_file);
  safeFree(name);
  log_state= LOG_CLOSED;
  DBUG_RETURN(1);
}

MYSQL_LOG::MYSQL_LOG()
  : name(0),  log_type(LOG_UNKNOWN), log_state(LOG_CLOSED), write_error(FALSE),
    inited(FALSE)
{
  /*
    We don't want to initialize LOCK_Log here as such initialization depends on
    safe_mutex (when using safe_mutex) which depends on MY_INIT(), which is
    called only in main(). Doing initialization here would make it happen
    before main().
  */
  bzero((char*) &log_file, sizeof(log_file));
}

void MYSQL_LOG::init_pthread_objects()
{
  DBUG_ASSERT(inited == 0);
  inited= 1;
  (void) pthread_mutex_init(&LOCK_log, MY_MUTEX_INIT_SLOW);
}

/*
  Close the log file

  SYNOPSIS
    close()
    exiting     Bitmask. For the slow and general logs the only used bit is
                LOG_CLOSE_TO_BE_OPENED. This is used if we intend to call
                open at once after close.

  NOTES
    One can do an open on the object at once after doing a close.
    The internal structures are not freed until cleanup() is called
*/

void MYSQL_LOG::close(uint exiting)
{					// One can't set log_type here!
  DBUG_ENTER("MYSQL_LOG::close");
  DBUG_PRINT("enter",("exiting: %d", (int) exiting));
  if (log_state == LOG_OPENED)
  {
    end_io_cache(&log_file);

    if (my_sync(log_file.file, MYF(MY_WME)) && ! write_error)
    {
      write_error= 1;
      sql_print_error(ER(ER_ERROR_ON_WRITE), name, errno);
    }

    if (my_close(log_file.file, MYF(MY_WME)) && ! write_error)
    {
      write_error= 1;
      sql_print_error(ER(ER_ERROR_ON_WRITE), name, errno);
    }
  }

  log_state= (exiting & LOG_CLOSE_TO_BE_OPENED) ? LOG_TO_BE_OPENED : LOG_CLOSED;
  safeFree(name);
  DBUG_VOID_RETURN;
}

/* this is called only once */

void MYSQL_LOG::cleanup()
{
  DBUG_ENTER("cleanup");
  if (inited)
  {
    inited= 0;
    (void) pthread_mutex_destroy(&LOCK_log);
    close(0);
  }
  DBUG_VOID_RETURN;
}


int MYSQL_LOG::generate_new_name(char *new_name, const char *log_name)
{
  fn_format(new_name, log_name, mysql_data_home, "", 4);
  if (log_type == LOG_BIN)
  {
    if (!fn_ext(log_name)[0])
    {
      if (find_uniq_filename(new_name))
      {
	sql_print_error(ER(ER_NO_UNIQUE_LOGFILE), log_name);
	return 1;
      }
    }
  }
  return 0;
}


/*
  Reopen the log file

  SYNOPSIS
    reopen_file()

  DESCRIPTION
    Reopen the log file. The method is used during FLUSH LOGS
    and locks LOCK_log mutex
*/


void MYSQL_QUERY_LOG::reopen_file()
{
  char *save_name;

  DBUG_ENTER("MYSQL_LOG::reopen_file");
  if (!is_open())
  {
    DBUG_PRINT("info",("log is closed"));
    DBUG_VOID_RETURN;
  }

  pthread_mutex_lock(&LOCK_log);

  save_name= name;
  name= 0;				// Don't free name
  close(LOG_CLOSE_TO_BE_OPENED);

  /*
     Note that at this point, log_state != LOG_CLOSED (important for is_open()).
  */

  open(save_name, log_type, 0, io_cache_type);
  my_free(save_name, MYF(0));

  pthread_mutex_unlock(&LOCK_log);

  DBUG_VOID_RETURN;
}


/*
  Write a command to traditional general log file

  SYNOPSIS
    write()

    event_time        command start timestamp
    user_host         the pointer to the string with user@host info
    user_host_len     length of the user_host string. this is computed once
                      and passed to all general log  event handlers
    thread_id         Id of the thread, issued a query
    command_type      the type of the command being logged
    command_type_len  the length of the string above
    sql_text          the very text of the query being executed
    sql_text_len      the length of sql_text string

  DESCRIPTION

   Log given command to to normal (not rotable) log file

  RETURN
    FASE - OK
    TRUE - error occured
*/

bool MYSQL_QUERY_LOG::write(time_t event_time, const char *user_host,
                            uint user_host_len, int thread_id,
                            const char *command_type, uint command_type_len,
                            const char *sql_text, uint sql_text_len)
{
  char buff[32];
  uint length= 0;
  char time_buff[MAX_TIME_SIZE];
  struct tm start;
  uint time_buff_len= 0;

  /* Test if someone closed between the is_open test and lock */
  if (is_open())
  {
    /* Note that my_b_write() assumes it knows the length for this */
      if (event_time != last_time)
      {
        last_time= event_time;

        localtime_r(&event_time, &start);

        time_buff_len= my_snprintf(time_buff, MAX_TIME_SIZE,
                                   "%02d%02d%02d %2d:%02d:%02d",
                                   start.tm_year % 100, start.tm_mon + 1,
                                   start.tm_mday, start.tm_hour,
                                   start.tm_min, start.tm_sec);

        if (my_b_write(&log_file, (byte*) &time_buff, time_buff_len))
          goto err;
      }
      else
        if (my_b_write(&log_file, (byte*) "\t\t" ,2) < 0)
          goto err;

      /* command_type, thread_id */
      length= my_snprintf(buff, 32, "%5ld ", (long) thread_id);

    if (my_b_write(&log_file, (byte*) buff, length))
      goto err;

    if (my_b_write(&log_file, (byte*) command_type, command_type_len))
      goto err;

    if (my_b_write(&log_file, (byte*) "\t", 1))
      goto err;

    /* sql_text */
    if (my_b_write(&log_file, (byte*) sql_text, sql_text_len))
      goto err;

    if (my_b_write(&log_file, (byte*) "\n", 1) ||
        flush_io_cache(&log_file))
      goto err;
  }

  return FALSE;
err:

  if (!write_error)
  {
    write_error= 1;
    sql_print_error(ER(ER_ERROR_ON_WRITE), name, errno);
  }
  return TRUE;
}


/*
  Log a query to the traditional slow log file

  SYNOPSIS
    write()

    thd               THD of the query
    current_time      current timestamp
    query_start_arg   command start timestamp
    user_host         the pointer to the string with user@host info
    user_host_len     length of the user_host string. this is computed once
                      and passed to all general log event handlers
    query_time        Amount of time the query took to execute (in seconds)
    lock_time         Amount of time the query was locked (in seconds)
    is_command        The flag, which determines, whether the sql_text is a
                      query or an administrator command.
    sql_text          the very text of the query or administrator command
                      processed
    sql_text_len      the length of sql_text string

  DESCRIPTION

   Log a query to the slow log file.

  RETURN
    FALSE - OK
    TRUE - error occured
*/

bool MYSQL_QUERY_LOG::write(THD *thd, time_t current_time,
                            time_t query_start_arg, const char *user_host,
                            uint user_host_len, longlong query_time,
                            longlong lock_time, bool is_command,
                            const char *sql_text, uint sql_text_len)
{
  bool error= 0;
  DBUG_ENTER("MYSQL_QUERY_LOG::write");

  if (!is_open())
    DBUG_RETURN(0);

  if (is_open())
  {						// Safety agains reopen
    int tmp_errno= 0;
    char buff[80], *end;
    uint buff_len;
    end= buff;

    if (!(specialflag & SPECIAL_SHORT_LOG_FORMAT))
    {
      if (current_time != last_time)
      {
        last_time= current_time;
        struct tm start;
        localtime_r(&current_time, &start);

        buff_len= my_snprintf(buff, sizeof buff,
                              "# Time: %02d%02d%02d %2d:%02d:%02d\n",
                              start.tm_year % 100, start.tm_mon + 1,
                              start.tm_mday, start.tm_hour,
                              start.tm_min, start.tm_sec);

        /* Note that my_b_write() assumes it knows the length for this */
        if (my_b_write(&log_file, (byte*) buff, buff_len))
          tmp_errno= errno;
      }
      if (my_b_printf(&log_file, "# User@Host: ", sizeof("# User@Host: ") - 1)
          != sizeof("# User@Host: ") - 1)
        tmp_errno= errno;
      if (my_b_printf(&log_file, user_host, user_host_len) != user_host_len)
        tmp_errno= errno;
      if (my_b_write(&log_file, (byte*) "\n", 1))
        tmp_errno= errno;
    }
    /* For slow query log */
    if (my_b_printf(&log_file,
                    "# Query_time: %lu  Lock_time: %lu"
                    " Rows_sent: %lu  Rows_examined: %lu\n",
                    (ulong) query_time, (ulong) lock_time,
                    (ulong) thd->sent_row_count,
                    (ulong) thd->examined_row_count) == (uint) -1)
      tmp_errno= errno;
    if (thd->db && strcmp(thd->db, db))
    {						// Database changed
      if (my_b_printf(&log_file,"use %s;\n",thd->db) == (uint) -1)
        tmp_errno= errno;
      strmov(db,thd->db);
    }
    if (thd->stmt_depends_on_first_successful_insert_id_in_prev_stmt)
    {
      end=strmov(end, ",last_insert_id=");
      end=longlong10_to_str((longlong)
                            thd->first_successful_insert_id_in_prev_stmt_for_binlog,
                            end, -10);
    }
    // Save value if we do an insert.
    if (thd->auto_inc_intervals_in_cur_stmt_for_binlog.nb_elements() > 0)
    {
      if (!(specialflag & SPECIAL_SHORT_LOG_FORMAT))
      {
        end=strmov(end,",insert_id=");
        end=longlong10_to_str((longlong)
                              thd->auto_inc_intervals_in_cur_stmt_for_binlog.minimum(),
                              end, -10);
      }
    }

    /*
      This info used to show up randomly, depending on whether the query
      checked the query start time or not. now we always write current
      timestamp to the slow log
    */
    end= strmov(end, ",timestamp=");
    end= int10_to_str((long) current_time, end, 10);

    if (end != buff)
    {
      *end++=';';
      *end='\n';
      if (my_b_write(&log_file, (byte*) "SET ", 4) ||
          my_b_write(&log_file, (byte*) buff + 1, (uint) (end-buff)))
        tmp_errno= errno;
    }
    if (is_command)
    {
      end= strxmov(buff, "# administrator command: ", NullS);
      buff_len= (ulong) (end - buff);
      my_b_write(&log_file, (byte*) buff, buff_len);
    }
    if (my_b_write(&log_file, (byte*) sql_text, sql_text_len) ||
        my_b_write(&log_file, (byte*) ";\n",2) ||
        flush_io_cache(&log_file))
      tmp_errno= errno;
    if (tmp_errno)
    {
      error= 1;
      if (! write_error)
      {
        write_error= 1;
        sql_print_error(ER(ER_ERROR_ON_WRITE), name, error);
      }
    }
  }
  DBUG_RETURN(error);
}


const char *MYSQL_LOG::generate_name(const char *log_name,
                                      const char *suffix,
                                      bool strip_ext, char *buff)
{
  if (!log_name || !log_name[0])
  {
    /*
      TODO: The following should be using fn_format();  We just need to
      first change fn_format() to cut the file name if it's too long.
    */
    strmake(buff, pidfile_name, FN_REFLEN - 5);
    strmov(fn_ext(buff), suffix);
    return (const char *)buff;
  }
  // get rid of extension if the log is binary to avoid problems
  if (strip_ext)
  {
    char *p= fn_ext(log_name);
    uint length= (uint) (p - log_name);
    strmake(buff, log_name, min(length, FN_REFLEN));
    return (const char*)buff;
  }
  return log_name;
}



MYSQL_BIN_LOG::MYSQL_BIN_LOG()
  :bytes_written(0), prepared_xids(0), file_id(1), open_count(1),
   need_start_event(TRUE), m_table_map_version(0),
   description_event_for_exec(0), description_event_for_queue(0)
{
  /*
    We don't want to initialize locks here as such initialization depends on
    safe_mutex (when using safe_mutex) which depends on MY_INIT(), which is
    called only in main(). Doing initialization here would make it happen
    before main().
  */
  index_file_name[0] = 0;
  bzero((char*) &index_file, sizeof(index_file));
}

/* this is called only once */

void MYSQL_BIN_LOG::cleanup()
{
  DBUG_ENTER("cleanup");
  if (inited)
  {
    inited= 0;
    close(LOG_CLOSE_INDEX|LOG_CLOSE_STOP_EVENT);
    delete description_event_for_queue;
    delete description_event_for_exec;
    (void) pthread_mutex_destroy(&LOCK_log);
    (void) pthread_mutex_destroy(&LOCK_index);
    (void) pthread_cond_destroy(&update_cond);
  }
  DBUG_VOID_RETURN;
}


/* Init binlog-specific vars */
void MYSQL_BIN_LOG::init(bool no_auto_events_arg, ulong max_size_arg)
{
  DBUG_ENTER("MYSQL_BIN_LOG::init");
  no_auto_events= no_auto_events_arg;
  max_size= max_size_arg;
  DBUG_PRINT("info",("max_size: %lu", max_size));
  DBUG_VOID_RETURN;
}


void MYSQL_BIN_LOG::init_pthread_objects()
{
  DBUG_ASSERT(inited == 0);
  inited= 1;
  (void) pthread_mutex_init(&LOCK_log, MY_MUTEX_INIT_SLOW);
  (void) pthread_mutex_init(&LOCK_index, MY_MUTEX_INIT_SLOW);
  (void) pthread_cond_init(&update_cond, 0);
}


bool MYSQL_BIN_LOG::open_index_file(const char *index_file_name_arg,
                                const char *log_name)
{
  File index_file_nr= -1;
  DBUG_ASSERT(!my_b_inited(&index_file));

  /*
    First open of this class instance
    Create an index file that will hold all file names uses for logging.
    Add new entries to the end of it.
  */
  myf opt= MY_UNPACK_FILENAME;
  if (!index_file_name_arg)
  {
    index_file_name_arg= log_name;    // Use same basename for index file
    opt= MY_UNPACK_FILENAME | MY_REPLACE_EXT;
  }
  fn_format(index_file_name, index_file_name_arg, mysql_data_home,
            ".index", opt);
  if ((index_file_nr= my_open(index_file_name,
                              O_RDWR | O_CREAT | O_BINARY ,
                              MYF(MY_WME))) < 0 ||
       my_sync(index_file_nr, MYF(MY_WME)) ||
       init_io_cache(&index_file, index_file_nr,
                     IO_SIZE, WRITE_CACHE,
                     my_seek(index_file_nr,0L,MY_SEEK_END,MYF(0)),
			0, MYF(MY_WME | MY_WAIT_IF_FULL)))
  {
    if (index_file_nr >= 0)
      my_close(index_file_nr,MYF(0));
    return TRUE;
  }
  return FALSE;
}


/*
  Open a (new) binlog file.

  DESCRIPTION
  - Open the log file and the index file. Register the new
    file name in it
  - When calling this when the file is in use, you must have a locks
    on LOCK_log and LOCK_index.

  RETURN VALUES
    0	ok
    1	error
*/

bool MYSQL_BIN_LOG::open(const char *log_name,
                         enum_log_type log_type_arg,
                         const char *new_name,
                         enum cache_type io_cache_type_arg,
                         bool no_auto_events_arg,
                         ulong max_size_arg,
                         bool null_created_arg)
{
  File file= -1;
  DBUG_ENTER("MYSQL_BIN_LOG::open");
  DBUG_PRINT("enter",("log_type: %d",(int) log_type_arg));

  write_error=0;

  /* open the main log file */
  if (MYSQL_LOG::open(log_name, log_type_arg, new_name, io_cache_type_arg))
    DBUG_RETURN(1);                            /* all warnings issued */

  init(no_auto_events_arg, max_size_arg);

  open_count++;

  DBUG_ASSERT(log_type == LOG_BIN);

  {
    bool write_file_name_to_index_file=0;

    if (!my_b_filelength(&log_file))
    {
      /*
	The binary log file was empty (probably newly created)
	This is the normal case and happens when the user doesn't specify
	an extension for the binary log files.
	In this case we write a standard header to it.
      */
      if (my_b_safe_write(&log_file, (byte*) BINLOG_MAGIC,
			  BIN_LOG_HEADER_SIZE))
        goto err;
      bytes_written+= BIN_LOG_HEADER_SIZE;
      write_file_name_to_index_file= 1;
    }

    DBUG_ASSERT(my_b_inited(&index_file) != 0);
    reinit_io_cache(&index_file, WRITE_CACHE,
                    my_b_filelength(&index_file), 0, 0);
    if (need_start_event && !no_auto_events)
    {
      /*
        In 4.x we set need_start_event=0 here, but in 5.0 we want a Start event
        even if this is not the very first binlog.
      */
      Format_description_log_event s(BINLOG_VERSION);
      /*
        don't set LOG_EVENT_BINLOG_IN_USE_F for SEQ_READ_APPEND io_cache
        as we won't be able to reset it later
      */
      if (io_cache_type == WRITE_CACHE)
        s.flags|= LOG_EVENT_BINLOG_IN_USE_F;
      if (!s.is_valid())
        goto err;
      if (null_created_arg)
        s.created= 0;
      if (s.write(&log_file))
        goto err;
      bytes_written+= s.data_written;
    }
    if (description_event_for_queue &&
        description_event_for_queue->binlog_version>=4)
    {
      /*
        This is a relay log written to by the I/O slave thread.
        Write the event so that others can later know the format of this relay
        log.
        Note that this event is very close to the original event from the
        master (it has binlog version of the master, event types of the
        master), so this is suitable to parse the next relay log's event. It
        has been produced by
        Format_description_log_event::Format_description_log_event(char* buf,).
        Why don't we want to write the description_event_for_queue if this
        event is for format<4 (3.23 or 4.x): this is because in that case, the
        description_event_for_queue describes the data received from the
        master, but not the data written to the relay log (*conversion*),
        which is in format 4 (slave's).
      */
      /*
        Set 'created' to 0, so that in next relay logs this event does not
        trigger cleaning actions on the slave in
        Format_description_log_event::exec_event().
      */
      description_event_for_queue->created= 0;
      /* Don't set log_pos in event header */
      description_event_for_queue->artificial_event=1;

      if (description_event_for_queue->write(&log_file))
        goto err;
      bytes_written+= description_event_for_queue->data_written;
    }
    if (flush_io_cache(&log_file) ||
        my_sync(log_file.file, MYF(MY_WME)))
      goto err;

    if (write_file_name_to_index_file)
    {
      /*
        As this is a new log file, we write the file name to the index
        file. As every time we write to the index file, we sync it.
      */
      if (my_b_write(&index_file, (byte*) log_file_name,
		     strlen(log_file_name)) ||
	  my_b_write(&index_file, (byte*) "\n", 1) ||
	  flush_io_cache(&index_file) ||
          my_sync(index_file.file, MYF(MY_WME)))
	goto err;
    }
  }
  log_state= LOG_OPENED;

  DBUG_RETURN(0);

err:
  sql_print_error("Could not use %s for logging (error %d). \
Turning logging off for the whole duration of the MySQL server process. \
To turn it on again: fix the cause, \
shutdown the MySQL server and restart it.", name, errno);
  if (file >= 0)
    my_close(file,MYF(0));
  end_io_cache(&log_file);
  end_io_cache(&index_file);
  safeFree(name);
  log_state= LOG_CLOSED;
  DBUG_RETURN(1);
}


int MYSQL_BIN_LOG::get_current_log(LOG_INFO* linfo)
{
  pthread_mutex_lock(&LOCK_log);
  int ret = raw_get_current_log(linfo);
  pthread_mutex_unlock(&LOCK_log);
  return ret;
}

int MYSQL_BIN_LOG::raw_get_current_log(LOG_INFO* linfo)
{
  strmake(linfo->log_file_name, log_file_name, sizeof(linfo->log_file_name)-1);
  linfo->pos = my_b_tell(&log_file);
  return 0;
}

/*
  Move all data up in a file in an filename index file

  SYNOPSIS
    copy_up_file_and_fill()
    index_file			File to move
    offset			Move everything from here to beginning

  NOTE
    File will be truncated to be 'offset' shorter or filled up with
    newlines

  IMPLEMENTATION
    We do the copy outside of the IO_CACHE as the cache buffers would just
    make things slower and more complicated.
    In most cases the copy loop should only do one read.

  RETURN VALUES
    0	ok
*/

#ifdef HAVE_REPLICATION

static bool copy_up_file_and_fill(IO_CACHE *index_file, my_off_t offset)
{
  int bytes_read;
  my_off_t init_offset= offset;
  File file= index_file->file;
  byte io_buf[IO_SIZE*2];
  DBUG_ENTER("copy_up_file_and_fill");

  for (;; offset+= bytes_read)
  {
    (void) my_seek(file, offset, MY_SEEK_SET, MYF(0));
    if ((bytes_read= (int) my_read(file, io_buf, sizeof(io_buf), MYF(MY_WME)))
	< 0)
      goto err;
    if (!bytes_read)
      break;					// end of file
    (void) my_seek(file, offset-init_offset, MY_SEEK_SET, MYF(0));
    if (my_write(file, (byte*) io_buf, bytes_read, MYF(MY_WME | MY_NABP)))
      goto err;
  }
  /* The following will either truncate the file or fill the end with \n' */
  if (my_chsize(file, offset - init_offset, '\n', MYF(MY_WME)) ||
      my_sync(file, MYF(MY_WME)))
    goto err;

  /* Reset data in old index cache */
  reinit_io_cache(index_file, READ_CACHE, (my_off_t) 0, 0, 1);
  DBUG_RETURN(0);

err:
  DBUG_RETURN(1);
}

#endif /* HAVE_REPLICATION */

/*
  Find the position in the log-index-file for the given log name

  SYNOPSIS
    find_log_pos()
    linfo		Store here the found log file name and position to
			the NEXT log file name in the index file.
    log_name		Filename to find in the index file.
			Is a null pointer if we want to read the first entry
    need_lock		Set this to 1 if the parent doesn't already have a
			lock on LOCK_index

  NOTE
    On systems without the truncate function the file will end with one or
    more empty lines.  These will be ignored when reading the file.

  RETURN VALUES
    0			ok
    LOG_INFO_EOF	End of log-index-file found
    LOG_INFO_IO		Got IO error while reading file
*/

int MYSQL_BIN_LOG::find_log_pos(LOG_INFO *linfo, const char *log_name,
			    bool need_lock)
{
  int error= 0;
  char *fname= linfo->log_file_name;
  uint log_name_len= log_name ? (uint) strlen(log_name) : 0;
  DBUG_ENTER("find_log_pos");
  DBUG_PRINT("enter",("log_name: %s", log_name ? log_name : "NULL"));

  /*
    Mutex needed because we need to make sure the file pointer does not
    move from under our feet
  */
  if (need_lock)
    pthread_mutex_lock(&LOCK_index);
  safe_mutex_assert_owner(&LOCK_index);

  /* As the file is flushed, we can't get an error here */
  (void) reinit_io_cache(&index_file, READ_CACHE, (my_off_t) 0, 0, 0);

  for (;;)
  {
    uint length;
    my_off_t offset= my_b_tell(&index_file);
    /* If we get 0 or 1 characters, this is the end of the file */

    if ((length= my_b_gets(&index_file, fname, FN_REFLEN)) <= 1)
    {
      /* Did not find the given entry; Return not found or error */
      error= !index_file.error ? LOG_INFO_EOF : LOG_INFO_IO;
      break;
    }

    // if the log entry matches, null string matching anything
    if (!log_name ||
	(log_name_len == length-1 && fname[log_name_len] == '\n' &&
	 !memcmp(fname, log_name, log_name_len)))
    {
      DBUG_PRINT("info",("Found log file entry"));
      fname[length-1]=0;			// remove last \n
      linfo->index_file_start_offset= offset;
      linfo->index_file_offset = my_b_tell(&index_file);
      break;
    }
  }

  if (need_lock)
    pthread_mutex_unlock(&LOCK_index);
  DBUG_RETURN(error);
}


/*
  Find the position in the log-index-file for the given log name

  SYNOPSIS
    find_next_log()
    linfo		Store here the next log file name and position to
			the file name after that.
    need_lock		Set this to 1 if the parent doesn't already have a
			lock on LOCK_index

  NOTE
    - Before calling this function, one has to call find_log_pos()
      to set up 'linfo'
    - Mutex needed because we need to make sure the file pointer does not move
      from under our feet

  RETURN VALUES
    0			ok
    LOG_INFO_EOF	End of log-index-file found
    LOG_INFO_IO		Got IO error while reading file
*/

int MYSQL_BIN_LOG::find_next_log(LOG_INFO* linfo, bool need_lock)
{
  int error= 0;
  uint length;
  char *fname= linfo->log_file_name;

  if (need_lock)
    pthread_mutex_lock(&LOCK_index);
  safe_mutex_assert_owner(&LOCK_index);

  /* As the file is flushed, we can't get an error here */
  (void) reinit_io_cache(&index_file, READ_CACHE, linfo->index_file_offset, 0,
			 0);

  linfo->index_file_start_offset= linfo->index_file_offset;
  if ((length=my_b_gets(&index_file, fname, FN_REFLEN)) <= 1)
  {
    error = !index_file.error ? LOG_INFO_EOF : LOG_INFO_IO;
    goto err;
  }
  fname[length-1]=0;				// kill \n
  linfo->index_file_offset = my_b_tell(&index_file);

err:
  if (need_lock)
    pthread_mutex_unlock(&LOCK_index);
  return error;
}


/*
  Delete all logs refered to in the index file
  Start writing to a new log file.  The new index file will only contain
  this file.

  SYNOPSIS
     reset_logs()
     thd		Thread

  NOTE
    If not called from slave thread, write start event to new log


  RETURN VALUES
    0	ok
    1   error
*/

bool MYSQL_BIN_LOG::reset_logs(THD* thd)
{
  LOG_INFO linfo;
  bool error=0;
  const char* save_name;
  DBUG_ENTER("reset_logs");

  ha_reset_logs(thd);
  /*
    We need to get both locks to be sure that no one is trying to
    write to the index log file.
  */
  pthread_mutex_lock(&LOCK_log);
  pthread_mutex_lock(&LOCK_index);

  /*
    The following mutex is needed to ensure that no threads call
    'delete thd' as we would then risk missing a 'rollback' from this
    thread. If the transaction involved MyISAM tables, it should go
    into binlog even on rollback.
  */
  VOID(pthread_mutex_lock(&LOCK_thread_count));

  /* Save variables so that we can reopen the log */
  save_name=name;
  name=0;					// Protect against free
  close(LOG_CLOSE_TO_BE_OPENED);

  /* First delete all old log files */

  if (find_log_pos(&linfo, NullS, 0))
  {
    error=1;
    goto err;
  }

  for (;;)
  {
    my_delete_allow_opened(linfo.log_file_name, MYF(MY_WME));
    if (find_next_log(&linfo, 0))
      break;
  }

  /* Start logging with a new file */
  close(LOG_CLOSE_INDEX);
  my_delete_allow_opened(index_file_name, MYF(MY_WME));	// Reset (open will update)
  if (!thd->slave_thread)
    need_start_event=1;
  if (!open_index_file(index_file_name, 0))
    open(save_name, log_type, 0, io_cache_type, no_auto_events, max_size, 0);
  my_free((gptr) save_name, MYF(0));

err:
  VOID(pthread_mutex_unlock(&LOCK_thread_count));
  pthread_mutex_unlock(&LOCK_index);
  pthread_mutex_unlock(&LOCK_log);
  DBUG_RETURN(error);
}


/*
  Delete relay log files prior to rli->group_relay_log_name
  (i.e. all logs which are not involved in a non-finished group
  (transaction)), remove them from the index file and start on next relay log.

  SYNOPSIS
    purge_first_log()
    rli		 Relay log information
    included     If false, all relay logs that are strictly before
                 rli->group_relay_log_name are deleted ; if true, the latter is
                 deleted too (i.e. all relay logs
                 read by the SQL slave thread are deleted).

  NOTE
    - This is only called from the slave-execute thread when it has read
      all commands from a relay log and want to switch to a new relay log.
    - When this happens, we can be in an active transaction as
      a transaction can span over two relay logs
      (although it is always written as a single block to the master's binary 
      log, hence cannot span over two master's binary logs).

  IMPLEMENTATION
    - Protects index file with LOCK_index
    - Delete relevant relay log files
    - Copy all file names after these ones to the front of the index file
    - If the OS has truncate, truncate the file, else fill it with \n'
    - Read the next file name from the index file and store in rli->linfo

  RETURN VALUES
    0			ok
    LOG_INFO_EOF	End of log-index-file found
    LOG_INFO_SEEK	Could not allocate IO cache
    LOG_INFO_IO		Got IO error while reading file
*/

#ifdef HAVE_REPLICATION

int MYSQL_BIN_LOG::purge_first_log(struct st_relay_log_info* rli, bool included) 
{
  int error;
  DBUG_ENTER("purge_first_log");

  DBUG_ASSERT(is_open());
  DBUG_ASSERT(rli->slave_running == 1);
  DBUG_ASSERT(!strcmp(rli->linfo.log_file_name,rli->event_relay_log_name));

  pthread_mutex_lock(&LOCK_index);
  pthread_mutex_lock(&rli->log_space_lock);
  rli->relay_log.purge_logs(rli->group_relay_log_name, included,
                            0, 0, &rli->log_space_total);
  // Tell the I/O thread to take the relay_log_space_limit into account
  rli->ignore_log_space_limit= 0;
  pthread_mutex_unlock(&rli->log_space_lock);

  /*
    Ok to broadcast after the critical region as there is no risk of
    the mutex being destroyed by this thread later - this helps save
    context switches
  */
  pthread_cond_broadcast(&rli->log_space_cond);
  
  /*
    Read the next log file name from the index file and pass it back to
    the caller
    If included is true, we want the first relay log;
    otherwise we want the one after event_relay_log_name.
  */
  if ((included && (error=find_log_pos(&rli->linfo, NullS, 0))) ||
      (!included &&
       ((error=find_log_pos(&rli->linfo, rli->event_relay_log_name, 0)) ||
        (error=find_next_log(&rli->linfo, 0)))))
  {
    char buff[22];
    sql_print_error("next log error: %d  offset: %s  log: %s included: %d",
                    error,
                    llstr(rli->linfo.index_file_offset,buff),
                    rli->group_relay_log_name,
                    included);
    goto err;
  }

  /*
    Reset rli's coordinates to the current log.
  */
  rli->event_relay_log_pos= BIN_LOG_HEADER_SIZE;
  strmake(rli->event_relay_log_name,rli->linfo.log_file_name,
	  sizeof(rli->event_relay_log_name)-1);

  /*
    If we removed the rli->group_relay_log_name file,
    we must update the rli->group* coordinates, otherwise do not touch it as the
    group's execution is not finished (e.g. COMMIT not executed)
  */
  if (included)
  {
    rli->group_relay_log_pos = BIN_LOG_HEADER_SIZE;
    strmake(rli->group_relay_log_name,rli->linfo.log_file_name,
            sizeof(rli->group_relay_log_name)-1);
    rli->notify_group_relay_log_name_update();
  }

  /* Store where we are in the new file for the execution thread */
  flush_relay_log_info(rli);

err:
  pthread_mutex_unlock(&LOCK_index);
  DBUG_RETURN(error);
}

/*
  Update log index_file
*/

int MYSQL_BIN_LOG::update_log_index(LOG_INFO* log_info, bool need_update_threads)
{
  if (copy_up_file_and_fill(&index_file, log_info->index_file_start_offset))
    return LOG_INFO_IO;

  // now update offsets in index file for running threads
  if (need_update_threads)
    adjust_linfo_offsets(log_info->index_file_start_offset);
  return 0;
}

/*
  Remove all logs before the given log from disk and from the index file.

  SYNOPSIS
    purge_logs()
    to_log	        Delete all log file name before this file. 
    included            If true, to_log is deleted too.
    need_mutex
    need_update_threads If we want to update the log coordinates of
                        all threads. False for relay logs, true otherwise.
    freed_log_space     If not null, decrement this variable of
                        the amount of log space freed

  NOTES
    If any of the logs before the deleted one is in use,
    only purge logs up to this one.

  RETURN VALUES
    0				ok
    LOG_INFO_EOF		to_log not found
*/

int MYSQL_BIN_LOG::purge_logs(const char *to_log, 
                          bool included,
                          bool need_mutex, 
                          bool need_update_threads, 
                          ulonglong *decrease_log_space)
{
  int error;
  int ret = 0;
  bool exit_loop= 0;
  LOG_INFO log_info;
  DBUG_ENTER("purge_logs");
  DBUG_PRINT("info",("to_log= %s",to_log));

  if (need_mutex)
    pthread_mutex_lock(&LOCK_index);
  if ((error=find_log_pos(&log_info, to_log, 0 /*no mutex*/)))
    goto err;

  /*
    File name exists in index file; delete until we find this file
    or a file that is used.
  */
  if ((error=find_log_pos(&log_info, NullS, 0 /*no mutex*/)))
    goto err;
  while ((strcmp(to_log,log_info.log_file_name) || (exit_loop=included)) &&
         !log_in_use(log_info.log_file_name))
  {
    ulong file_size= 0;
    if (decrease_log_space) //stat the file we want to delete
    {
      MY_STAT s;

      /* 
         If we could not stat, we can't know the amount
         of space that deletion will free. In most cases,
         deletion won't work either, so it's not a problem.
      */
      if (my_stat(log_info.log_file_name,&s,MYF(0)))
        file_size= s.st_size;
      else
	sql_print_information("Failed to execute my_stat on file '%s'",
			      log_info.log_file_name);
    }
    /*
      It's not fatal if we can't delete a log file ;
      if we could delete it, take its size into account
    */
    DBUG_PRINT("info",("purging %s",log_info.log_file_name));
    if (!my_delete(log_info.log_file_name, MYF(0)) && decrease_log_space)
      *decrease_log_space-= file_size;

    ha_binlog_index_purge_file(current_thd, log_info.log_file_name);
    if (current_thd->query_error) {
      DBUG_PRINT("info",("query error: %d", current_thd->query_error));
      if (my_errno == EMFILE) {
        DBUG_PRINT("info",("my_errno: %d, set ret = LOG_INFO_EMFILE", my_errno));
        ret = LOG_INFO_EMFILE;
        break;
      }
    }

    if (find_next_log(&log_info, 0) || exit_loop)
      break;
  }

  /*
    If we get killed -9 here, the sysadmin would have to edit
    the log index file after restart - otherwise, this should be safe
  */
  error= update_log_index(&log_info, need_update_threads);
  if (error == 0) {
    error = ret;
  }

err:
  if (need_mutex)
    pthread_mutex_unlock(&LOCK_index);
  DBUG_RETURN(error);
}

/*
  Remove all logs before the given file date from disk and from the
  index file.

  SYNOPSIS
    purge_logs_before_date()
    thd		Thread pointer
    before_date	Delete all log files before given date.

  NOTES
    If any of the logs before the deleted one is in use,
    only purge logs up to this one.

  RETURN VALUES
    0				ok
    LOG_INFO_PURGE_NO_ROTATE	Binary file that can't be rotated
*/

int MYSQL_BIN_LOG::purge_logs_before_date(time_t purge_time)
{
  int error;
  LOG_INFO log_info;
  MY_STAT stat_area;

  DBUG_ENTER("purge_logs_before_date");

  pthread_mutex_lock(&LOCK_index);

  /*
    Delete until we find curren file
    or a file that is used or a file
    that is older than purge_time.
  */
  if ((error=find_log_pos(&log_info, NullS, 0 /*no mutex*/)))
    goto err;

  while (strcmp(log_file_name, log_info.log_file_name) &&
	 !log_in_use(log_info.log_file_name))
  {
    /* It's not fatal even if we can't delete a log file */
    if (!my_stat(log_info.log_file_name, &stat_area, MYF(0)) ||
	stat_area.st_mtime >= purge_time)
      break;
    my_delete(log_info.log_file_name, MYF(0));

    ha_binlog_index_purge_file(current_thd, log_info.log_file_name);

    if (find_next_log(&log_info, 0))
      break;
  }

  /*
    If we get killed -9 here, the sysadmin would have to edit
    the log index file after restart - otherwise, this should be safe
  */
  error= update_log_index(&log_info, 1);

err:
  pthread_mutex_unlock(&LOCK_index);
  DBUG_RETURN(error);
}
#endif /* HAVE_REPLICATION */


/*
  Create a new log file name

  SYNOPSIS
    make_log_name()
    buf			buf of at least FN_REFLEN where new name is stored

  NOTE
    If file name will be longer then FN_REFLEN it will be truncated
*/

void MYSQL_BIN_LOG::make_log_name(char* buf, const char* log_ident)
{
  uint dir_len = dirname_length(log_file_name); 
  if (dir_len > FN_REFLEN)
    dir_len=FN_REFLEN-1;
  strnmov(buf, log_file_name, dir_len);
  strmake(buf+dir_len, log_ident, FN_REFLEN - dir_len);
}


/*
  Check if we are writing/reading to the given log file
*/

bool MYSQL_BIN_LOG::is_active(const char *log_file_name_arg)
{
  return !strcmp(log_file_name, log_file_name_arg);
}


/*
  Wrappers around new_file_impl to avoid using argument
  to control locking. The argument 1) less readable 2) breaks
  incapsulation 3) allows external access to the class without
  a lock (which is not possible with private new_file_without_locking
  method).
*/

void MYSQL_BIN_LOG::new_file()
{
  new_file_impl(1);
}


void MYSQL_BIN_LOG::new_file_without_locking()
{
  new_file_impl(0);
}


/*
  Start writing to a new log file or reopen the old file

  SYNOPSIS
    new_file_impl()
    need_lock		Set to 1 if caller has not locked LOCK_log

  NOTE
    The new file name is stored last in the index file
*/

void MYSQL_BIN_LOG::new_file_impl(bool need_lock)
{
  char new_name[FN_REFLEN], *new_name_ptr, *old_name;

  DBUG_ENTER("MYSQL_BIN_LOG::new_file_impl");
  if (!is_open())
  {
    DBUG_PRINT("info",("log is closed"));
    DBUG_VOID_RETURN;
  }

  if (need_lock)
    pthread_mutex_lock(&LOCK_log);
  pthread_mutex_lock(&LOCK_index);

  safe_mutex_assert_owner(&LOCK_log);
  safe_mutex_assert_owner(&LOCK_index);

  /*
    if binlog is used as tc log, be sure all xids are "unlogged",
    so that on recover we only need to scan one - latest - binlog file
    for prepared xids. As this is expected to be a rare event,
    simple wait strategy is enough. We're locking LOCK_log to be sure no
    new Xid_log_event's are added to the log (and prepared_xids is not
    increased), and waiting on COND_prep_xids for late threads to
    catch up.
  */
  if (prepared_xids)
  {
    tc_log_page_waits++;
    pthread_mutex_lock(&LOCK_prep_xids);
    while (prepared_xids)
      pthread_cond_wait(&COND_prep_xids, &LOCK_prep_xids);
    pthread_mutex_unlock(&LOCK_prep_xids);
  }

  /* Reuse old name if not binlog and not update log */
  new_name_ptr= name;

  /*
    If user hasn't specified an extension, generate a new log name
    We have to do this here and not in open as we want to store the
    new file name in the current binary log file.
  */
  if (generate_new_name(new_name, name))
    goto end;
  new_name_ptr=new_name;

  if (log_type == LOG_BIN)
  {
    if (!no_auto_events)
    {
      /*
        We log the whole file name for log file as the user may decide
        to change base names at some point.
      */
      Rotate_log_event r(new_name+dirname_length(new_name),
                         0, LOG_EVENT_OFFSET, 0);
      r.write(&log_file);
      bytes_written += r.data_written;
    }
    /*
      Update needs to be signalled even if there is no rotate event
      log rotation should give the waiting thread a signal to
      discover EOF and move on to the next log.
    */
    signal_update();
  }
  old_name=name;
  name=0;				// Don't free name
  close(LOG_CLOSE_TO_BE_OPENED);

  /*
     Note that at this point, log_state != LOG_CLOSED (important for is_open()).
  */

  /*
     new_file() is only used for rotation (in FLUSH LOGS or because size >
     max_binlog_size or max_relay_log_size).
     If this is a binary log, the Format_description_log_event at the beginning of
     the new file should have created=0 (to distinguish with the
     Format_description_log_event written at server startup, which should
     trigger temp tables deletion on slaves.
  */

  open(old_name, log_type, new_name_ptr,
       io_cache_type, no_auto_events, max_size, 1);
  my_free(old_name,MYF(0));

end:
  if (need_lock)
    pthread_mutex_unlock(&LOCK_log);
  pthread_mutex_unlock(&LOCK_index);

  DBUG_VOID_RETURN;
}


bool MYSQL_BIN_LOG::append(Log_event* ev)
{
  bool error = 0;
  pthread_mutex_lock(&LOCK_log);
  DBUG_ENTER("MYSQL_BIN_LOG::append");

  DBUG_ASSERT(log_file.type == SEQ_READ_APPEND);
  /*
    Log_event::write() is smart enough to use my_b_write() or
    my_b_append() depending on the kind of cache we have.
  */
  if (ev->write(&log_file))
  {
    error=1;
    goto err;
  }
  bytes_written+= ev->data_written;
  DBUG_PRINT("info",("max_size: %lu",max_size));
  if ((uint) my_b_append_tell(&log_file) > max_size)
    new_file_without_locking();

err:
  pthread_mutex_unlock(&LOCK_log);
  signal_update();				// Safe as we don't call close
  DBUG_RETURN(error);
}


bool MYSQL_BIN_LOG::appendv(const char* buf, uint len,...)
{
  bool error= 0;
  DBUG_ENTER("MYSQL_BIN_LOG::appendv");
  va_list(args);
  va_start(args,len);

  DBUG_ASSERT(log_file.type == SEQ_READ_APPEND);

  safe_mutex_assert_owner(&LOCK_log);
  do
  {
    if (my_b_append(&log_file,(byte*) buf,len))
    {
      error= 1;
      goto err;
    }
    bytes_written += len;
  } while ((buf=va_arg(args,const char*)) && (len=va_arg(args,uint)));
  DBUG_PRINT("info",("max_size: %lu",max_size));
  if ((uint) my_b_append_tell(&log_file) > max_size)
    new_file_without_locking();

err:
  if (!error)
    signal_update();
  DBUG_RETURN(error);
}


bool MYSQL_BIN_LOG::flush_and_sync()
{
  int err=0, fd=log_file.file;
  safe_mutex_assert_owner(&LOCK_log);
  if (flush_io_cache(&log_file))
    return 1;
  if (++sync_binlog_counter >= sync_binlog_period && sync_binlog_period)
  {
    sync_binlog_counter= 0;
    err=my_sync(fd, MYF(MY_WME));
  }
  return err;
}

void MYSQL_BIN_LOG::start_union_events(THD *thd)
{
  DBUG_ASSERT(!thd->binlog_evt_union.do_union);
  thd->binlog_evt_union.do_union= TRUE;
  thd->binlog_evt_union.unioned_events= FALSE;
  thd->binlog_evt_union.unioned_events_trans= FALSE;
  thd->binlog_evt_union.first_query_id= thd->query_id;
}

void MYSQL_BIN_LOG::stop_union_events(THD *thd)
{
  DBUG_ASSERT(thd->binlog_evt_union.do_union);
  thd->binlog_evt_union.do_union= FALSE;
}

bool MYSQL_BIN_LOG::is_query_in_union(THD *thd, query_id_t query_id_param)
{
  return (thd->binlog_evt_union.do_union && 
          query_id_param >= thd->binlog_evt_union.first_query_id);
}


/*
  These functions are placed in this file since they need access to
  binlog_hton, which has internal linkage.
*/

int THD::binlog_setup_trx_data()
{
  DBUG_ENTER("THD::binlog_setup_trx_data");
  binlog_trx_data *trx_data=
    (binlog_trx_data*) ha_data[binlog_hton->slot];

  if (trx_data)
    DBUG_RETURN(0);                             // Already set up

  ha_data[binlog_hton->slot]= trx_data=
    (binlog_trx_data*) my_malloc(sizeof(binlog_trx_data), MYF(MY_ZEROFILL));
  if (!trx_data ||
      open_cached_file(&trx_data->trans_log, mysql_tmpdir,
                       LOG_PREFIX, binlog_cache_size, MYF(MY_WME)))
  {
    my_free((gptr)trx_data, MYF(MY_ALLOW_ZERO_PTR));
    ha_data[binlog_hton->slot]= 0;
    DBUG_RETURN(1);                      // Didn't manage to set it up
  }

  trx_data= new (ha_data[binlog_hton->slot]) binlog_trx_data;

  DBUG_RETURN(0);
}

/*
  Function to start a statement and optionally a transaction for the
  binary log.

  SYNOPSIS
    binlog_start_trans_and_stmt()

  DESCRIPTION

    This function does three things:
    - Start a transaction if not in autocommit mode or if a BEGIN
      statement has been seen.

    - Start a statement transaction to allow us to truncate the binary
      log.

    - Save the currrent binlog position so that we can roll back the
      statement by truncating the transaction log.

      We only update the saved position if the old one was undefined,
      the reason is that there are some cases (e.g., for CREATE-SELECT)
      where the position is saved twice (e.g., both in
      select_create::prepare() and THD::binlog_write_table_map()) , but
      we should use the first. This means that calls to this function
      can be used to start the statement before the first table map
      event, to include some extra events.
 */

void
THD::binlog_start_trans_and_stmt()
{
  binlog_trx_data *trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
  DBUG_ENTER("binlog_start_trans_and_stmt");
  DBUG_PRINT("enter", ("trx_data: 0x%lx  trx_data->before_stmt_pos: %lu",
                       (long) trx_data,
                       (trx_data ? (ulong) trx_data->before_stmt_pos :
                        (ulong) 0)));

  if (trx_data == NULL ||
      trx_data->before_stmt_pos == MY_OFF_T_UNDEF)
  {
    this->binlog_set_stmt_begin();
    if (options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN))
      trans_register_ha(this, TRUE, binlog_hton);
    trans_register_ha(this, FALSE, binlog_hton);
  }
  DBUG_VOID_RETURN;
}

void THD::binlog_set_stmt_begin() {
  binlog_trx_data *trx_data=
    (binlog_trx_data*) ha_data[binlog_hton->slot];

  /*
    The call to binlog_trans_log_savepos() might create the trx_data
    structure, if it didn't exist before, so we save the position
    into an auto variable and then write it into the transaction
    data for the binary log (i.e., trx_data).
  */
  my_off_t pos= 0;
  binlog_trans_log_savepos(this, &pos);
  trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
  trx_data->before_stmt_pos= pos;
}

int THD::binlog_flush_transaction_cache()
{
  DBUG_ENTER("binlog_flush_transaction_cache");
  binlog_trx_data *trx_data= (binlog_trx_data*) ha_data[binlog_hton->slot];
  DBUG_PRINT("enter", ("trx_data: 0x%lx", (ulong) trx_data));
  if (trx_data)
    DBUG_PRINT("enter", ("trx_data->before_stmt_pos: %lu",
                         (ulong) trx_data->before_stmt_pos));

  /*
    Write the transaction cache to the binary log.  We don't flush and
    sync the log file since we don't know if more will be written to
    it. If the caller want the log file sync:ed, the caller has to do
    it.

    The transaction data is only reset upon a successful write of the
    cache to the binary log.
  */

  if (trx_data && likely(mysql_bin_log.is_open())) {
    if (int error= mysql_bin_log.write_cache(&trx_data->trans_log, true, true))
      DBUG_RETURN(error);
    trx_data->reset();
  }

  DBUG_RETURN(0);
}


/*
  Write a table map to the binary log.
 */

int THD::binlog_write_table_map(TABLE *table, bool is_trans)
{
  int error;
  DBUG_ENTER("THD::binlog_write_table_map");
  DBUG_PRINT("enter", ("table: 0x%lx  (%s: #%lu)",
                       (long) table, table->s->table_name.str,
                       table->s->table_map_id));

  /* Pre-conditions */
  DBUG_ASSERT(current_stmt_binlog_row_based && mysql_bin_log.is_open());
  DBUG_ASSERT(table->s->table_map_id != ULONG_MAX);

  Table_map_log_event::flag_set const
    flags= Table_map_log_event::TM_NO_FLAGS;

  Table_map_log_event
    the_event(this, table, table->s->table_map_id, is_trans, flags);

  if (is_trans && binlog_table_maps == 0)
    binlog_start_trans_and_stmt();

  if ((error= mysql_bin_log.write(&the_event)))
    DBUG_RETURN(error);

  binlog_table_maps++;
  table->s->table_map_version= mysql_bin_log.table_map_version();
  DBUG_RETURN(0);
}

Rows_log_event*
THD::binlog_get_pending_rows_event() const
{
  binlog_trx_data *const trx_data=
    (binlog_trx_data*) ha_data[binlog_hton->slot];
  /*
    This is less than ideal, but here's the story: If there is no
    trx_data, prepare_pending_rows_event() has never been called
    (since the trx_data is set up there). In that case, we just return
    NULL.
   */
  return trx_data ? trx_data->pending() : NULL;
}

void
THD::binlog_set_pending_rows_event(Rows_log_event* ev)
{
  if (ha_data[binlog_hton->slot] == NULL)
    binlog_setup_trx_data();

  binlog_trx_data *const trx_data=
    (binlog_trx_data*) ha_data[binlog_hton->slot];

  DBUG_ASSERT(trx_data);
  trx_data->set_pending(ev);
}


/*
  Moves the last bunch of rows from the pending Rows event to the binlog
  (either cached binlog if transaction, or disk binlog). Sets a new pending
  event.
*/
int
MYSQL_BIN_LOG::flush_and_set_pending_rows_event(THD *thd,
                                                Rows_log_event* event)
{
  DBUG_ENTER("MYSQL_BIN_LOG::flush_and_set_pending_rows_event(event)");
  DBUG_ASSERT(mysql_bin_log.is_open());
  DBUG_PRINT("enter", ("event: 0x%lx", (long) event));

  int error= 0;

  binlog_trx_data *const trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];

  DBUG_ASSERT(trx_data);

  DBUG_PRINT("info", ("trx_data->pending(): 0x%lx", (long) trx_data->pending()));

  if (Rows_log_event* pending= trx_data->pending())
  {
    IO_CACHE *file= &log_file;

    /*
      Decide if we should write to the log file directly or to the
      transaction log.
    */
    if (pending->get_cache_stmt() || my_b_tell(&trx_data->trans_log))
      file= &trx_data->trans_log;

    /*
      If we are writing to the log file directly, we could avoid
      locking the log. This does not work since we need to step the
      m_table_map_version below, and that change has to be protected
      by the LOCK_log mutex.
    */
    pthread_mutex_lock(&LOCK_log);

    /*
      Write pending event to log file or transaction cache
    */
    if (pending->write(file))
    {
      pthread_mutex_unlock(&LOCK_log);
      DBUG_RETURN(1);
    }

    /*
      We step the table map version if we are writing an event
      representing the end of a statement.  We do this regardless of
      wheather we write to the transaction cache or to directly to the
      file.

      In an ideal world, we could avoid stepping the table map version
      if we were writing to a transaction cache, since we could then
      reuse the table map that was written earlier in the transaction
      cache.  This does not work since STMT_END_F implies closing all
      table mappings on the slave side.

      TODO: Find a solution so that table maps does not have to be
      written several times within a transaction.
     */
    if (pending->get_flags(Rows_log_event::STMT_END_F))
      ++m_table_map_version;

    delete pending;

    if (file == &log_file)
    {
      error= flush_and_sync();
      if (!error)
      {
        signal_update();
        rotate_and_purge(RP_LOCK_LOG_IS_ALREADY_LOCKED);
      }
    }

    pthread_mutex_unlock(&LOCK_log);
  }

  thd->binlog_set_pending_rows_event(event);

  DBUG_RETURN(error);
}

/*
  Write an event to the binary log
*/

bool MYSQL_BIN_LOG::write(Log_event *event_info)
{
  THD *thd= event_info->thd;
  bool error= 1;
  DBUG_ENTER("MYSQL_BIN_LOG::write(Log_event *)");

  if (thd->binlog_evt_union.do_union)
  {
    /*
      In Stored function; Remember that function call caused an update.
      We will log the function call to the binary log on function exit
    */
    thd->binlog_evt_union.unioned_events= TRUE;
    thd->binlog_evt_union.unioned_events_trans |= event_info->cache_stmt;
    DBUG_RETURN(0);
  }

  /*
    Flush the pending rows event to the transaction cache or to the
    log file.  Since this function potentially aquire the LOCK_log
    mutex, we do this before aquiring the LOCK_log mutex in this
    function.

    We only end the statement if we are in a top-level statement.  If
    we are inside a stored function, we do not end the statement since
    this will close all tables on the slave.
  */
  bool const end_stmt=
    thd->prelocked_mode && thd->lex->requires_prelocking();
  thd->binlog_flush_pending_rows_event(end_stmt);

  pthread_mutex_lock(&LOCK_log);

  /*
     In most cases this is only called if 'is_open()' is true; in fact this is
     mostly called if is_open() *was* true a few instructions before, but it
     could have changed since.
  */
  if (likely(is_open()))
  {
    IO_CACHE *file= &log_file;
#ifdef HAVE_REPLICATION
    /*
      In the future we need to add to the following if tests like
      "do the involved tables match (to be implemented)
      binlog_[wild_]{do|ignore}_table?" (WL#1049)"
    */
    const char *local_db= event_info->get_db();
    if ((thd && !(thd->options & OPTION_BIN_LOG)) ||
	(!binlog_filter->db_ok(local_db)))
    {
      VOID(pthread_mutex_unlock(&LOCK_log));
      DBUG_PRINT("info",("OPTION_BIN_LOG is %s, db_ok('%s') == %d",
                         (thd->options & OPTION_BIN_LOG) ? "set" : "clear",
                         local_db, binlog_filter->db_ok(local_db)));
      DBUG_RETURN(0);
    }
#endif /* HAVE_REPLICATION */

#if defined(USING_TRANSACTIONS) 
    /*
      Should we write to the binlog cache or to the binlog on disk?
      Write to the binlog cache if:
      - it is already not empty (meaning we're in a transaction; note that the
     present event could be about a non-transactional table, but still we need
     to write to the binlog cache in that case to handle updates to mixed
     trans/non-trans table types the best possible in binlogging)
      - or if the event asks for it (cache_stmt == TRUE).
    */
    if (opt_using_transactions && thd)
    {
      if (thd->binlog_setup_trx_data())
        goto err;

      binlog_trx_data *const trx_data=
        (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
      IO_CACHE *trans_log= &trx_data->trans_log;
      my_off_t trans_log_pos= my_b_tell(trans_log);
      if (event_info->get_cache_stmt() || trans_log_pos != 0)
      {
        DBUG_PRINT("info", ("Using trans_log: cache: %d, trans_log_pos: %lu",
                            event_info->get_cache_stmt(),
                            (ulong) trans_log_pos));
        if (trans_log_pos == 0)
          thd->binlog_start_trans_and_stmt();
        file= trans_log;
      }
      /*
        TODO as Mats suggested, for all the cases above where we write to
        trans_log, it sounds unnecessary to lock LOCK_log. We should rather
        test first if we want to write to trans_log, and if not, lock
        LOCK_log.
      */
    }
#endif /* USING_TRANSACTIONS */
    DBUG_PRINT("info",("event type: %d",event_info->get_type_code()));

    /*
      No check for auto events flag here - this write method should
      never be called if auto-events are enabled
    */

    /*
      1. Write first log events which describe the 'run environment'
      of the SQL command
    */

    /*
      If row-based binlogging, Insert_id, Rand and other kind of "setting
      context" events are not needed.
    */
    if (thd)
    {
      if (!thd->current_stmt_binlog_row_based)
      {
        if (thd->stmt_depends_on_first_successful_insert_id_in_prev_stmt)
        {
          Intvar_log_event e(thd,(uchar) LAST_INSERT_ID_EVENT,
                             thd->first_successful_insert_id_in_prev_stmt_for_binlog);
          if (e.write(file))
            goto err;
        }
        if (thd->auto_inc_intervals_in_cur_stmt_for_binlog.nb_elements() > 0)
        {
          DBUG_PRINT("info",("number of auto_inc intervals: %u",
                             thd->auto_inc_intervals_in_cur_stmt_for_binlog.
                             nb_elements()));
          /*
            If the auto_increment was second in a table's index (possible with
            MyISAM or BDB) (table->next_number_key_offset != 0), such event is
            in fact not necessary. We could avoid logging it.
          */
          Intvar_log_event e(thd, (uchar) INSERT_ID_EVENT,
                             thd->auto_inc_intervals_in_cur_stmt_for_binlog.
                             minimum());
          if (e.write(file))
            goto err;
        }
        if (thd->rand_used)
        {
          Rand_log_event e(thd,thd->rand_saved_seed1,thd->rand_saved_seed2);
          if (e.write(file))
            goto err;
        }
        if (thd->user_var_events.elements)
        {
          for (uint i= 0; i < thd->user_var_events.elements; i++)
          {
            BINLOG_USER_VAR_EVENT *user_var_event;
            get_dynamic(&thd->user_var_events,(gptr) &user_var_event, i);
            User_var_log_event e(thd, user_var_event->user_var_event->name.str,
                                 user_var_event->user_var_event->name.length,
                                 user_var_event->value,
                                 user_var_event->length,
                                 user_var_event->type,
                                 user_var_event->charset_number);
            if (e.write(file))
              goto err;
          }
        }
      }
    }

    /*
       Write the SQL command
     */

    if (event_info->write(file))
      goto err;

    if (file == &log_file) // we are writing to the real log (disk)
    {
      if (flush_and_sync())
	goto err;
      signal_update();
      rotate_and_purge(RP_LOCK_LOG_IS_ALREADY_LOCKED);
    }
    error=0;

err:
    if (error)
    {
      if (my_errno == EFBIG)
	my_message(ER_TRANS_CACHE_FULL, ER(ER_TRANS_CACHE_FULL), MYF(0));
      else
	my_error(ER_ERROR_ON_WRITE, MYF(0), name, errno);
      write_error=1;
    }
  }

  if (event_info->flags & LOG_EVENT_UPDATE_TABLE_MAP_VERSION_F)
    ++m_table_map_version;

  pthread_mutex_unlock(&LOCK_log);
  DBUG_RETURN(error);
}


int error_log_print(enum loglevel level, const char *format,
                    va_list args)
{
  return logger.error_log_print(level, format, args);
}


bool slow_log_print(THD *thd, const char *query, uint query_length,
                    time_t query_start_arg)
{
  return logger.slow_log_print(thd, query, query_length, query_start_arg);
}


bool general_log_print(THD *thd, enum enum_server_command command,
                       const char *format, ...)
{
  va_list args;
  uint error= 0;

  va_start(args, format);
  error= logger.general_log_print(thd, command, format, args);
  va_end(args);

  return error;
}

void MYSQL_BIN_LOG::rotate_and_purge(uint flags)
{
  if (!(flags & RP_LOCK_LOG_IS_ALREADY_LOCKED))
    pthread_mutex_lock(&LOCK_log);
  if ((flags & RP_FORCE_ROTATE) ||
      (my_b_tell(&log_file) >= (my_off_t) max_size))
  {
    new_file_without_locking();
#ifdef HAVE_REPLICATION
    if (expire_logs_days)
    {
      long purge_time= time(0) - expire_logs_days*24*60*60;
      if (purge_time >= 0)
        purge_logs_before_date(purge_time);
    }
#endif
  }
  if (!(flags & RP_LOCK_LOG_IS_ALREADY_LOCKED))
    pthread_mutex_unlock(&LOCK_log);
}

uint MYSQL_BIN_LOG::next_file_id()
{
  uint res;
  pthread_mutex_lock(&LOCK_log);
  res = file_id++;
  pthread_mutex_unlock(&LOCK_log);
  return res;
}


/*
  Write the contents of a cache to the binary log.

  SYNOPSIS
    write_cache()
    cache    Cache to write to the binary log
    lock_log True if the LOCK_log mutex should be aquired, false otherwise
    sync_log True if the log should be flushed and sync:ed

  DESCRIPTION
    Write the contents of the cache to the binary log. The cache will
    be reset as a READ_CACHE to be able to read the contents from it.
 */

int MYSQL_BIN_LOG::write_cache(IO_CACHE *cache, bool lock_log, bool sync_log)
{
  Mutex_sentry sentry(lock_log ? &LOCK_log : NULL);

  if (reinit_io_cache(cache, READ_CACHE, 0, 0, 0))
    return ER_ERROR_ON_WRITE;
  uint bytes= my_b_bytes_in_cache(cache);
  do
  {
    if (my_b_write(&log_file, cache->read_pos, bytes))
      return ER_ERROR_ON_WRITE;
    cache->read_pos= cache->read_end;
  } while ((bytes= my_b_fill(cache)));

  if (sync_log)
    flush_and_sync();

  return 0;                                     // All OK
}

/*
  Write a cached log entry to the binary log

  SYNOPSIS
    write()
    thd
    cache		The cache to copy to the binlog
    commit_event        The commit event to print after writing the
                        contents of the cache.

  NOTE
    - We only come here if there is something in the cache.
    - The thing in the cache is always a complete transaction
    - 'cache' needs to be reinitialized after this functions returns.

  IMPLEMENTATION
    - To support transaction over replication, we wrap the transaction
      with BEGIN/COMMIT or BEGIN/ROLLBACK in the binary log.
      We want to write a BEGIN/ROLLBACK block when a non-transactional table
      was updated in a transaction which was rolled back. This is to ensure
      that the same updates are run on the slave.
*/

bool MYSQL_BIN_LOG::write(THD *thd, IO_CACHE *cache, Log_event *commit_event)
{
  DBUG_ENTER("MYSQL_BIN_LOG::write(THD *, IO_CACHE *, Log_event *)");
  VOID(pthread_mutex_lock(&LOCK_log));

  /* NULL would represent nothing to replicate after ROLLBACK */
  DBUG_ASSERT(commit_event != NULL);

  if (likely(is_open()))                       // Should always be true
  {
    /*
      We only bother to write to the binary log if there is anything
      to write.
     */
    if (my_b_tell(cache) > 0)
    {
      /*
        Log "BEGIN" at the beginning of the transaction.
        which may contain more than 1 SQL statement.
      */
      if (thd->options & (OPTION_NOT_AUTOCOMMIT | OPTION_BEGIN))
      {
        Query_log_event qinfo(thd, STRING_WITH_LEN("BEGIN"), TRUE, FALSE);
        /*
          Imagine this is rollback due to net timeout, after all statements of
          the transaction succeeded. Then we want a zero-error code in BEGIN.
          In other words, if there was a really serious error code it's already
          in the statement's events, there is no need to put it also in this
          internally generated event, and as this event is generated late it
          would lead to false alarms.
          This is safer than thd->clear_error() against kills at shutdown.
        */
        qinfo.error_code= 0;
        /*
          Now this Query_log_event has artificial log_pos 0. It must be adjusted
          to reflect the real position in the log. Not doing it would confuse the
          slave: it would prevent this one from knowing where he is in the
          master's binlog, which would result in wrong positions being shown to
          the user, MASTER_POS_WAIT undue waiting etc.
        */
        if (qinfo.write(&log_file))
          goto err;
      }

      if ((write_error= write_cache(cache, false, false)))
        goto err;
      
      if (commit_event && commit_event->write(&log_file))
        goto err;
      if (flush_and_sync())
        goto err;
      DBUG_EXECUTE_IF("half_binlogged_transaction", abort(););
      if (cache->error)				// Error on read
      {
        sql_print_error(ER(ER_ERROR_ON_READ), cache->file_name, errno);
        write_error=1;				// Don't give more errors
        goto err;
      }
      signal_update();
    }

    /*
      if commit_event is Xid_log_event, increase the number of
      prepared_xids (it's decreasd in ::unlog()). Binlog cannot be rotated
      if there're prepared xids in it - see the comment in new_file() for
      an explanation.
      If the commit_event is not Xid_log_event (then it's a Query_log_event)
      rotate binlog, if necessary.
    */
    if (commit_event && commit_event->get_type_code() == XID_EVENT)
    {
      pthread_mutex_lock(&LOCK_prep_xids);
      prepared_xids++;
      pthread_mutex_unlock(&LOCK_prep_xids);
    }
    else
      rotate_and_purge(RP_LOCK_LOG_IS_ALREADY_LOCKED);
  }
  VOID(pthread_mutex_unlock(&LOCK_log));

  DBUG_RETURN(0);

err:
  if (!write_error)
  {
    write_error= 1;
    sql_print_error(ER(ER_ERROR_ON_WRITE), name, errno);
  }
  VOID(pthread_mutex_unlock(&LOCK_log));
  DBUG_RETURN(1);
}


/*
  Wait until we get a signal that the binary log has been updated

  SYNOPSIS
    wait_for_update()
    thd			Thread variable
    is_slave            If 0, the caller is the Binlog_dump thread from master;
                        if 1, the caller is the SQL thread from the slave. This
                        influences only thd->proc_info.

  NOTES
    One must have a lock on LOCK_log before calling this function.
    This lock will be released before return! That's required by
    THD::enter_cond() (see NOTES in sql_class.h).
*/

void MYSQL_BIN_LOG::wait_for_update(THD* thd, bool is_slave)
{
  const char *old_msg;
  DBUG_ENTER("wait_for_update");

  old_msg= thd->enter_cond(&update_cond, &LOCK_log,
                           is_slave ?
                           "Has read all relay log; waiting for the slave I/O "
                           "thread to update it" :
                           "Has sent all binlog to slave; waiting for binlog "
                           "to be updated");
  pthread_cond_wait(&update_cond, &LOCK_log);
  thd->exit_cond(old_msg);
  DBUG_VOID_RETURN;
}


/*
  Close the log file

  SYNOPSIS
    close()
    exiting     Bitmask for one or more of the following bits:
                LOG_CLOSE_INDEX if we should close the index file
                LOG_CLOSE_TO_BE_OPENED if we intend to call open
                at once after close.
                LOG_CLOSE_STOP_EVENT write a 'stop' event to the log

  NOTES
    One can do an open on the object at once after doing a close.
    The internal structures are not freed until cleanup() is called
*/

void MYSQL_BIN_LOG::close(uint exiting)
{					// One can't set log_type here!
  DBUG_ENTER("MYSQL_BIN_LOG::close");
  DBUG_PRINT("enter",("exiting: %d", (int) exiting));
  if (log_state == LOG_OPENED)
  {
#ifdef HAVE_REPLICATION
    if (log_type == LOG_BIN && !no_auto_events &&
	(exiting & LOG_CLOSE_STOP_EVENT))
    {
      Stop_log_event s;
      s.write(&log_file);
      bytes_written+= s.data_written;
      signal_update();
    }
#endif /* HAVE_REPLICATION */

    /* don't pwrite in a file opened with O_APPEND - it doesn't work */
    if (log_file.type == WRITE_CACHE && log_type == LOG_BIN)
    {
      my_off_t offset= BIN_LOG_HEADER_SIZE + FLAGS_OFFSET;
      byte flags=0; // clearing LOG_EVENT_BINLOG_IN_USE_F
      my_pwrite(log_file.file, &flags, 1, offset, MYF(0));
    }

    /* this will cleanup IO_CACHE, sync and close the file */
    MYSQL_LOG::close(exiting);
  }

  /*
    The following test is needed even if is_open() is not set, as we may have
    called a not complete close earlier and the index file is still open.
  */

  if ((exiting & LOG_CLOSE_INDEX) && my_b_inited(&index_file))
  {
    end_io_cache(&index_file);
    if (my_close(index_file.file, MYF(0)) < 0 && ! write_error)
    {
      write_error= 1;
      sql_print_error(ER(ER_ERROR_ON_WRITE), index_file_name, errno);
    }
  }
  log_state= (exiting & LOG_CLOSE_TO_BE_OPENED) ? LOG_TO_BE_OPENED : LOG_CLOSED;
  safeFree(name);
  DBUG_VOID_RETURN;
}


void MYSQL_BIN_LOG::set_max_size(ulong max_size_arg)
{
  /*
    We need to take locks, otherwise this may happen:
    new_file() is called, calls open(old_max_size), then before open() starts,
    set_max_size() sets max_size to max_size_arg, then open() starts and
    uses the old_max_size argument, so max_size_arg has been overwritten and
    it's like if the SET command was never run.
  */
  DBUG_ENTER("MYSQL_BIN_LOG::set_max_size");
  pthread_mutex_lock(&LOCK_log);
  if (is_open())
    max_size= max_size_arg;
  pthread_mutex_unlock(&LOCK_log);
  DBUG_VOID_RETURN;
}


/*
  Check if a string is a valid number

  SYNOPSIS
    test_if_number()
    str			String to test
    res			Store value here
    allow_wildcards	Set to 1 if we should ignore '%' and '_'

  NOTE
    For the moment the allow_wildcards argument is not used
    Should be move to some other file.

  RETURN VALUES
    1	String is a number
    0	Error
*/

static bool test_if_number(register const char *str,
			   long *res, bool allow_wildcards)
{
  reg2 int flag;
  const char *start;
  DBUG_ENTER("test_if_number");

  flag=0; start=str;
  while (*str++ == ' ') ;
  if (*--str == '-' || *str == '+')
    str++;
  while (my_isdigit(files_charset_info,*str) ||
	 (allow_wildcards && (*str == wild_many || *str == wild_one)))
  {
    flag=1;
    str++;
  }
  if (*str == '.')
  {
    for (str++ ;
	 my_isdigit(files_charset_info,*str) ||
	   (allow_wildcards && (*str == wild_many || *str == wild_one)) ;
	 str++, flag=1) ;
  }
  if (*str != 0 || flag == 0)
    DBUG_RETURN(0);
  if (res)
    *res=atol(start);
  DBUG_RETURN(1);			/* Number ok */
} /* test_if_number */


void print_buffer_to_file(enum loglevel level, const char *buffer)
{
  time_t skr;
  struct tm tm_tmp;
  struct tm *start;
  DBUG_ENTER("print_buffer_to_file");
  DBUG_PRINT("enter",("buffer: %s", buffer));

  VOID(pthread_mutex_lock(&LOCK_error_log));

  skr=time(NULL);
  localtime_r(&skr, &tm_tmp);
  start=&tm_tmp;

  fprintf(stderr, "%02d%02d%02d %2d:%02d:%02d [%s] %s\n",
          start->tm_year % 100,
          start->tm_mon+1,
          start->tm_mday,
          start->tm_hour,
          start->tm_min,
          start->tm_sec,
          (level == ERROR_LEVEL ? "ERROR" : level == WARNING_LEVEL ?
           "Warning" : "Note"),
          buffer);

  fflush(stderr);

  VOID(pthread_mutex_unlock(&LOCK_error_log));
  DBUG_VOID_RETURN;
}


void sql_perror(const char *message)
{
#ifdef HAVE_STRERROR
  sql_print_error("%s: %s",message, strerror(errno));
#else
  perror(message);
#endif
}


bool flush_error_log()
{
  bool result=0;
  if (opt_error_log)
  {
    char err_renamed[FN_REFLEN], *end;
    end= strmake(err_renamed,log_error_file,FN_REFLEN-4);
    strmov(end, "-old");
    VOID(pthread_mutex_lock(&LOCK_error_log));
#ifdef __WIN__
    char err_temp[FN_REFLEN+4];
    /*
     On Windows is necessary a temporary file for to rename
     the current error file.
    */
    strxmov(err_temp, err_renamed,"-tmp",NullS);
    (void) my_delete(err_temp, MYF(0)); 
    if (freopen(err_temp,"a+",stdout))
    {
      freopen(err_temp,"a+",stderr);
      (void) my_delete(err_renamed, MYF(0));
      my_rename(log_error_file,err_renamed,MYF(0));
      if (freopen(log_error_file,"a+",stdout))
        freopen(log_error_file,"a+",stderr);
      int fd, bytes;
      char buf[IO_SIZE];
      if ((fd = my_open(err_temp, O_RDONLY, MYF(0))) >= 0)
      {
        while ((bytes = (int) my_read(fd, (byte*) buf, IO_SIZE, MYF(0))) > 0)
             my_fwrite(stderr, (byte*) buf, bytes, MYF(0));
        my_close(fd, MYF(0));
      }
      (void) my_delete(err_temp, MYF(0)); 
    }
    else
     result= 1;
#else
   my_rename(log_error_file,err_renamed,MYF(0));
   if (freopen(log_error_file,"a+",stdout))
     freopen(log_error_file,"a+",stderr);
   else
     result= 1;
#endif
    VOID(pthread_mutex_unlock(&LOCK_error_log));
  }
   return result;
}

void MYSQL_BIN_LOG::signal_update()
{
  DBUG_ENTER("MYSQL_BIN_LOG::signal_update");
  pthread_cond_broadcast(&update_cond);
  DBUG_VOID_RETURN;
}

#ifdef __NT__
void print_buffer_to_nt_eventlog(enum loglevel level, char *buff,
                                 uint length, int buffLen)
{
  HANDLE event;
  char   *buffptr;
  LPCSTR *buffmsgptr;
  DBUG_ENTER("print_buffer_to_nt_eventlog");

  buffptr= buff;
  if (length > (uint)(buffLen-5))
  {
    char *newBuff= new char[length + 5];
    strcpy(newBuff, buff);
    buffptr= newBuff;
  }
  strmov(buffptr+length, "\r\n\r\n");
  buffmsgptr= (LPCSTR*) &buffptr;               // Keep windows happy

  setup_windows_event_source();
  if ((event= RegisterEventSource(NULL,"MySQL")))
  {
    switch (level) {
      case ERROR_LEVEL:
        ReportEvent(event, EVENTLOG_ERROR_TYPE, 0, MSG_DEFAULT, NULL, 1, 0,
                    buffmsgptr, NULL);
        break;
      case WARNING_LEVEL:
        ReportEvent(event, EVENTLOG_WARNING_TYPE, 0, MSG_DEFAULT, NULL, 1, 0,
                    buffmsgptr, NULL);
        break;
      case INFORMATION_LEVEL:
        ReportEvent(event, EVENTLOG_INFORMATION_TYPE, 0, MSG_DEFAULT, NULL, 1,
                    0, buffmsgptr, NULL);
        break;
    }
    DeregisterEventSource(event);
  }

  /* if we created a string buffer, then delete it */
  if (buffptr != buff)
    delete[] buffptr;

  DBUG_VOID_RETURN;
}
#endif /* __NT__ */


/*
  Prints a printf style message to the error log and, under NT, to the
  Windows event log.

  SYNOPSIS
    vprint_msg_to_log()
    event_type             Type of event to write (Error, Warning, or Info)
    format                 Printf style format of message
    args                   va_list list of arguments for the message

  NOTE

  IMPLEMENTATION
    This function prints the message into a buffer and then sends that buffer
    to other functions to write that message to other logging sources.

  RETURN VALUES
    The function always returns 0. The return value is present in the
    signature to be compatible with other logging routines, which could
    return an error (e.g. logging to the log tables)
*/

#ifdef EMBEDDED_LIBRARY
int vprint_msg_to_log(enum loglevel level __attribute__((unused)),
                       const char *format __attribute__((unused)),
                       va_list argsi __attribute__((unused)))
{
  DBUG_ENTER("vprint_msg_to_log");
  DBUG_RETURN(0);
}
#else /*!EMBEDDED_LIBRARY*/
int vprint_msg_to_log(enum loglevel level, const char *format, va_list args)
{
  char   buff[1024];
  uint length;
  DBUG_ENTER("vprint_msg_to_log");

  /* "- 5" is because of print_buffer_to_nt_eventlog() */
  length= my_vsnprintf(buff, sizeof(buff) - 5, format, args);
  print_buffer_to_file(level, buff);

#ifdef __NT__
  print_buffer_to_nt_eventlog(level, buff, length, sizeof(buff));
#endif

  DBUG_RETURN(0);
}
#endif /*EMBEDDED_LIBRARY*/


void sql_print_error(const char *format, ...) 
{
  va_list args;
  DBUG_ENTER("sql_print_error");

  va_start(args, format);
  error_log_print(ERROR_LEVEL, format, args);
  va_end(args);

  DBUG_VOID_RETURN;
}


void sql_print_warning(const char *format, ...) 
{
  va_list args;
  DBUG_ENTER("sql_print_warning");

  va_start(args, format);
  error_log_print(WARNING_LEVEL, format, args);
  va_end(args);

  DBUG_VOID_RETURN;
}


void sql_print_information(const char *format, ...) 
{
  va_list args;
  DBUG_ENTER("sql_print_information");

  va_start(args, format);
  error_log_print(INFORMATION_LEVEL, format, args);
  va_end(args);

  DBUG_VOID_RETURN;
}


/********* transaction coordinator log for 2pc - mmap() based solution *******/

/*
  the log consists of a file, mmapped to a memory.
  file is divided on pages of tc_log_page_size size.
  (usable size of the first page is smaller because of log header)
  there's PAGE control structure for each page
  each page (or rather PAGE control structure) can be in one of three
  states - active, syncing, pool.
  there could be only one page in active or syncing states,
  but many in pool - pool is fifo queue.
  usual lifecycle of a page is pool->active->syncing->pool
  "active" page - is a page where new xid's are logged.
  the page stays active as long as syncing slot is taken.
  "syncing" page is being synced to disk. no new xid can be added to it.
  when the sync is done the page is moved to a pool and an active page
  becomes "syncing".

  the result of such an architecture is a natural "commit grouping" -
  If commits are coming faster than the system can sync, they do not
  stall. Instead, all commit that came since the last sync are
  logged to the same page, and they all are synced with the next -
  one - sync. Thus, thought individual commits are delayed, throughput
  is not decreasing.

  when a xid is added to an active page, the thread of this xid waits
  for a page's condition until the page is synced. when syncing slot
  becomes vacant one of these waiters is awaken to take care of syncing.
  it syncs the page and signals all waiters that the page is synced.
  PAGE::waiters is used to count these waiters, and a page may never
  become active again until waiters==0 (that is all waiters from the
  previous sync have noticed the sync was completed)

  note, that the page becomes "dirty" and has to be synced only when a
  new xid is added into it. Removing a xid from a page does not make it
  dirty - we don't sync removals to disk.
*/

ulong tc_log_page_waits= 0;

#ifdef HAVE_MMAP

#define TC_LOG_HEADER_SIZE (sizeof(tc_log_magic)+1)

static const char tc_log_magic[]={(char) 254, 0x23, 0x05, 0x74};

ulong opt_tc_log_size= TC_LOG_MIN_SIZE;
ulong tc_log_max_pages_used=0, tc_log_page_size=0, tc_log_cur_pages_used=0;

int TC_LOG_MMAP::open(const char *opt_name)
{
  uint i;
  bool crashed=FALSE;
  PAGE *pg;

  DBUG_ASSERT(total_ha_2pc > 1);
  DBUG_ASSERT(opt_name && opt_name[0]);

  tc_log_page_size= my_getpagesize();
  DBUG_ASSERT(TC_LOG_PAGE_SIZE % tc_log_page_size == 0);

  fn_format(logname,opt_name,mysql_data_home,"",MY_UNPACK_FILENAME);
  if ((fd= my_open(logname, O_RDWR, MYF(0))) < 0)
  {
    if (my_errno != ENOENT)
      goto err;
    if (using_heuristic_recover())
      return 1;
    if ((fd= my_create(logname, O_RDWR, 0, MYF(MY_WME))) < 0)
      goto err;
    inited=1;
    file_length= opt_tc_log_size;
    if (my_chsize(fd, file_length, 0, MYF(MY_WME)))
      goto err;
  }
  else
  {
    inited= 1;
    crashed= TRUE;
    sql_print_information("Recovering after a crash using %s", opt_name);
    if (tc_heuristic_recover)
    {
      sql_print_error("Cannot perform automatic crash recovery when "
                      "--tc-heuristic-recover is used");
      goto err;
    }
    file_length= my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME+MY_FAE));
    if (file_length == MY_FILEPOS_ERROR || file_length % tc_log_page_size)
      goto err;
  }

  data= (uchar *)my_mmap(0, (size_t)file_length, PROT_READ|PROT_WRITE,
                        MAP_NOSYNC|MAP_SHARED, fd, 0);
  if (data == MAP_FAILED)
  {
    my_errno=errno;
    goto err;
  }
  inited=2;

  npages=(uint)file_length/tc_log_page_size;
  DBUG_ASSERT(npages >= 3);             // to guarantee non-empty pool
  if (!(pages=(PAGE *)my_malloc(npages*sizeof(PAGE), MYF(MY_WME|MY_ZEROFILL))))
    goto err;
  inited=3;
  for (pg=pages, i=0; i < npages; i++, pg++)
  {
    pg->next=pg+1;
    pg->waiters=0;
    pg->state=POOL;
    pthread_mutex_init(&pg->lock, MY_MUTEX_INIT_FAST);
    pthread_cond_init (&pg->cond, 0);
    pg->start=(my_xid *)(data + i*tc_log_page_size);
    pg->end=(my_xid *)(pg->start + tc_log_page_size);
    pg->size=pg->free=tc_log_page_size/sizeof(my_xid);
  }
  pages[0].size=pages[0].free=
                (tc_log_page_size-TC_LOG_HEADER_SIZE)/sizeof(my_xid);
  pages[0].start=pages[0].end-pages[0].size;
  pages[npages-1].next=0;
  inited=4;

  if (crashed && recover())
      goto err;

  memcpy(data, tc_log_magic, sizeof(tc_log_magic));
  data[sizeof(tc_log_magic)]= (uchar)total_ha_2pc;
  my_msync(fd, data, tc_log_page_size, MS_SYNC);
  inited=5;

  pthread_mutex_init(&LOCK_sync,    MY_MUTEX_INIT_FAST);
  pthread_mutex_init(&LOCK_active,  MY_MUTEX_INIT_FAST);
  pthread_mutex_init(&LOCK_pool,    MY_MUTEX_INIT_FAST);
  pthread_cond_init(&COND_active, 0);
  pthread_cond_init(&COND_pool, 0);

  inited=6;

  syncing= 0;
  active=pages;
  pool=pages+1;
  pool_last=pages+npages-1;

  return 0;

err:
  close();
  return 1;
}

/*
  there is no active page, let's got one from the pool

  two strategies here:
  1. take the first from the pool
  2. if there're waiters - take the one with the most free space

  TODO page merging. try to allocate adjacent page first,
  so that they can be flushed both in one sync
*/
void TC_LOG_MMAP::get_active_from_pool()
{
  PAGE **p, **best_p=0;
  int best_free;

  if (syncing)
    pthread_mutex_lock(&LOCK_pool);

  do
  {
    best_p= p= &pool;
    if ((*p)->waiters == 0) // can the first page be used ?
      break;                // yes - take it.

    best_free=0;            // no - trying second strategy
    for (p=&(*p)->next; *p; p=&(*p)->next)
    {
      if ((*p)->waiters == 0 && (*p)->free > best_free)
      {
        best_free=(*p)->free;
        best_p=p;
      }
    }
  }
  while ((*best_p == 0 || best_free == 0) && overflow());

  active=*best_p;
  if (active->free == active->size) // we've chosen an empty page
  {
    tc_log_cur_pages_used++;
    set_if_bigger(tc_log_max_pages_used, tc_log_cur_pages_used);
  }

  if ((*best_p)->next)              // unlink the page from the pool
    *best_p=(*best_p)->next;
  else
    pool_last=*best_p;

  if (syncing)
    pthread_mutex_unlock(&LOCK_pool);
}

int TC_LOG_MMAP::overflow()
{
  /*
    simple overflow handling - just wait
    TODO perhaps, increase log size ?
    let's check the behaviour of tc_log_page_waits first
  */
  tc_log_page_waits++;
  pthread_cond_wait(&COND_pool, &LOCK_pool);
  return 1; // always return 1
}

/*
  Record that transaction XID is committed on the persistent storage

  NOTES
    This function is called in the middle of two-phase commit:
    First all resources prepare the transaction, then tc_log->log() is called,
    then all resources commit the transaction, then tc_log->unlog() is called.

    All access to active page is serialized but it's not a problem, as
    we're assuming that fsync() will be a main bottleneck.
    That is, parallelizing writes to log pages we'll decrease number of
    threads waiting for a page, but then all these threads will be waiting
    for a fsync() anyway

  IMPLEMENTATION
   If tc_log == MYSQL_LOG then tc_log writes transaction to binlog and
   records XID in a special Xid_log_event.
   If tc_log = TC_LOG_MMAP then xid is written in a special memory-mapped
   log.

  RETURN
    0  Error
    #  "cookie", a number that will be passed as an argument
       to unlog() call. tc_log can define it any way it wants,
       and use for whatever purposes. TC_LOG_MMAP sets it
       to the position in memory where xid was logged to.
*/

int TC_LOG_MMAP::log_xid(THD *thd, my_xid xid)
{
  int err;
  PAGE *p;
  ulong cookie;

  pthread_mutex_lock(&LOCK_active);

  /*
    if active page is full - just wait...
    frankly speaking, active->free here accessed outside of mutex
    protection, but it's safe, because it only means we may miss an
    unlog() for the active page, and we're not waiting for it here -
    unlog() does not signal COND_active.
  */
  while (unlikely(active && active->free == 0))
    pthread_cond_wait(&COND_active, &LOCK_active);

  /* no active page ? take one from the pool */
  if (active == 0)
    get_active_from_pool();

  p=active;
  pthread_mutex_lock(&p->lock);

  /* searching for an empty slot */
  while (*p->ptr)
  {
    p->ptr++;
    DBUG_ASSERT(p->ptr < p->end);               // because p->free > 0
  }

  /* found! store xid there and mark the page dirty */
  cookie= (ulong)((uchar *)p->ptr - data);      // can never be zero
  *p->ptr++= xid;
  p->free--;
  p->state= DIRTY;

  /* to sync or not to sync - this is the question */
  pthread_mutex_unlock(&LOCK_active);
  pthread_mutex_lock(&LOCK_sync);
  pthread_mutex_unlock(&p->lock);

  if (syncing)
  {                                          // somebody's syncing. let's wait
    p->waiters++;
    /*
      note - it must be while (), not do ... while () here
      as p->state may be not DIRTY when we come here
    */
    while (p->state == DIRTY && syncing)
      pthread_cond_wait(&p->cond, &LOCK_sync);
    p->waiters--;
    err= p->state == ERROR;
    if (p->state != DIRTY)                   // page was synced
    {
      if (p->waiters == 0)
        pthread_cond_signal(&COND_pool);     // in case somebody's waiting
      pthread_mutex_unlock(&LOCK_sync);
      goto done;                             // we're done
    }
  }                                          // page was not synced! do it now
  DBUG_ASSERT(active == p && syncing == 0);
  pthread_mutex_lock(&LOCK_active);
  syncing=p;                                 // place is vacant - take it
  active=0;                                  // page is not active anymore
  pthread_cond_broadcast(&COND_active);      // in case somebody's waiting
  pthread_mutex_unlock(&LOCK_active);
  pthread_mutex_unlock(&LOCK_sync);
  err= sync();

done:
  return err ? 0 : cookie;
}

int TC_LOG_MMAP::sync()
{
  int err;

  DBUG_ASSERT(syncing != active);

  /*
    sit down and relax - this can take a while...
    note - no locks are held at this point
  */
  err= my_msync(fd, syncing->start, 1, MS_SYNC);

  /* page is synced. let's move it to the pool */
  pthread_mutex_lock(&LOCK_pool);
  pool_last->next=syncing;
  pool_last=syncing;
  syncing->next=0;
  syncing->state= err ? ERROR : POOL;
  pthread_cond_broadcast(&syncing->cond);    // signal "sync done"
  pthread_cond_signal(&COND_pool);           // in case somebody's waiting
  pthread_mutex_unlock(&LOCK_pool);

  /* marking 'syncing' slot free */
  pthread_mutex_lock(&LOCK_sync);
  syncing=0;
  pthread_cond_signal(&active->cond);        // wake up a new syncer
  pthread_mutex_unlock(&LOCK_sync);
  return err;
}

/*
  erase xid from the page, update page free space counters/pointers.
  cookie points directly to the memory where xid was logged
*/

void TC_LOG_MMAP::unlog(ulong cookie, my_xid xid)
{
  PAGE *p=pages+(cookie/tc_log_page_size);
  my_xid *x=(my_xid *)(data+cookie);

  DBUG_ASSERT(*x == xid);
  DBUG_ASSERT(x >= p->start && x < p->end);
  *x=0;

  pthread_mutex_lock(&p->lock);
  p->free++;
  DBUG_ASSERT(p->free <= p->size);
  set_if_smaller(p->ptr, x);
  if (p->free == p->size)               // the page is completely empty
    statistic_decrement(tc_log_cur_pages_used, &LOCK_status);
  if (p->waiters == 0)                 // the page is in pool and ready to rock
    pthread_cond_signal(&COND_pool);   // ping ... for overflow()
  pthread_mutex_unlock(&p->lock);
}

void TC_LOG_MMAP::close()
{
  uint i;
  switch (inited) {
  case 6:
    pthread_mutex_destroy(&LOCK_sync);
    pthread_mutex_destroy(&LOCK_active);
    pthread_mutex_destroy(&LOCK_pool);
    pthread_cond_destroy(&COND_pool);
  case 5:
    data[0]='A'; // garble the first (signature) byte, in case my_delete fails
  case 4:
    for (i=0; i < npages; i++)
    {
      if (pages[i].ptr == 0)
        break;
      pthread_mutex_destroy(&pages[i].lock);
      pthread_cond_destroy(&pages[i].cond);
    }
  case 3:
    my_free((gptr)pages, MYF(0));
  case 2:
    my_munmap((byte*)data, (size_t)file_length);
  case 1:
    my_close(fd, MYF(0));
  }
  if (inited>=5) // cannot do in the switch because of Windows
    my_delete(logname, MYF(MY_WME));
  inited=0;
}

int TC_LOG_MMAP::recover()
{
  HASH xids;
  PAGE *p=pages, *end_p=pages+npages;

  if (memcmp(data, tc_log_magic, sizeof(tc_log_magic)))
  {
    sql_print_error("Bad magic header in tc log");
    goto err1;
  }

  /*
    the first byte after magic signature is set to current
    number of storage engines on startup
  */
  if (data[sizeof(tc_log_magic)] != total_ha_2pc)
  {
    sql_print_error("Recovery failed! You must enable "
                    "exactly %d storage engines that support "
                    "two-phase commit protocol",
                    data[sizeof(tc_log_magic)]);
    goto err1;
  }

  if (hash_init(&xids, &my_charset_bin, tc_log_page_size/3, 0,
            sizeof(my_xid), 0, 0, MYF(0)))
    goto err1;

  for ( ; p < end_p ; p++)
  {
    for (my_xid *x=p->start; x < p->end; x++)
      if (*x && my_hash_insert(&xids, (byte *)x))
        goto err2; // OOM
  }

  if (ha_recover(&xids))
    goto err2;

  hash_free(&xids);
  bzero(data, (size_t)file_length);
  return 0;

err2:
  hash_free(&xids);
err1:
  sql_print_error("Crash recovery failed. Either correct the problem "
                  "(if it's, for example, out of memory error) and restart, "
                  "or delete tc log and start mysqld with "
                  "--tc-heuristic-recover={commit|rollback}");
  return 1;
}
#endif

TC_LOG *tc_log;
TC_LOG_DUMMY tc_log_dummy;
TC_LOG_MMAP  tc_log_mmap;

/*
  Perform heuristic recovery, if --tc-heuristic-recover was used

  RETURN VALUE
    0	no heuristic recovery was requested
    1   heuristic recovery was performed

  NOTE
    no matter whether heuristic recovery was successful or not
    mysqld must exit. So, return value is the same in both cases.
*/

int TC_LOG::using_heuristic_recover()
{
  if (!tc_heuristic_recover)
    return 0;

  sql_print_information("Heuristic crash recovery mode");
  if (ha_recover(0))
    sql_print_error("Heuristic crash recovery failed");
  sql_print_information("Please restart mysqld without --tc-heuristic-recover");
  return 1;
}

/****** transaction coordinator log for 2pc - binlog() based solution ******/
#define TC_LOG_BINLOG MYSQL_BIN_LOG

/*
  TODO keep in-memory list of prepared transactions
  (add to list in log(), remove on unlog())
  and copy it to the new binlog if rotated
  but let's check the behaviour of tc_log_page_waits first!
*/

int TC_LOG_BINLOG::open(const char *opt_name)
{
  LOG_INFO log_info;
  int      error= 1;

  DBUG_ASSERT(total_ha_2pc > 1);
  DBUG_ASSERT(opt_name && opt_name[0]);

  pthread_mutex_init(&LOCK_prep_xids, MY_MUTEX_INIT_FAST);
  pthread_cond_init (&COND_prep_xids, 0);

  if (!my_b_inited(&index_file))
  {
    /* There was a failure to open the index file, can't open the binlog */
    cleanup();
    return 1;
  }

  if (using_heuristic_recover())
  {
    /* generate a new binlog to mask a corrupted one */
    open(opt_name, LOG_BIN, 0, WRITE_CACHE, 0, max_binlog_size, 0);
    cleanup();
    return 1;
  }

  if ((error= find_log_pos(&log_info, NullS, 1)))
  {
    if (error != LOG_INFO_EOF)
      sql_print_error("find_log_pos() failed (error: %d)", error);
    else
      error= 0;
    goto err;
  }

  {
    const char *errmsg;
    IO_CACHE    log;
    File        file;
    Log_event  *ev=0;
    Format_description_log_event fdle(BINLOG_VERSION);
    char        log_name[FN_REFLEN];

    if (! fdle.is_valid())
      goto err;

    do
    {
      strmake(log_name, log_info.log_file_name, sizeof(log_name)-1);
    } while (!(error= find_next_log(&log_info, 1)));

    if (error !=  LOG_INFO_EOF)
    {
      sql_print_error("find_log_pos() failed (error: %d)", error);
      goto err;
    }

    if ((file= open_binlog(&log, log_name, &errmsg)) < 0)
    {
      sql_print_error("%s", errmsg);
      goto err;
    }

    if ((ev= Log_event::read_log_event(&log, 0, &fdle)) &&
        ev->get_type_code() == FORMAT_DESCRIPTION_EVENT &&
        ev->flags & LOG_EVENT_BINLOG_IN_USE_F)
    {
      sql_print_information("Recovering after a crash using %s", opt_name);
      error= recover(&log, (Format_description_log_event *)ev);
    }
    else
      error=0;

    delete ev;
    end_io_cache(&log);
    my_close(file, MYF(MY_WME));

    if (error)
      goto err;
  }

err:
  return error;
}

/* this is called on shutdown, after ha_panic */
void TC_LOG_BINLOG::close()
{
  DBUG_ASSERT(prepared_xids==0);
  pthread_mutex_destroy(&LOCK_prep_xids);
  pthread_cond_destroy (&COND_prep_xids);
}

/*
  TODO group commit

  RETURN
         0  - error
         1  - success
*/
int TC_LOG_BINLOG::log_xid(THD *thd, my_xid xid)
{
  DBUG_ENTER("TC_LOG_BINLOG::log");
  Xid_log_event xle(thd, xid);
  binlog_trx_data *trx_data=
    (binlog_trx_data*) thd->ha_data[binlog_hton->slot];
  /*
    We always commit the entire transaction when writing an XID. Also
    note that the return value is inverted.
   */
  DBUG_RETURN(!binlog_end_trans(thd, trx_data, &xle, TRUE));
}

void TC_LOG_BINLOG::unlog(ulong cookie, my_xid xid)
{
  pthread_mutex_lock(&LOCK_prep_xids);
  DBUG_ASSERT(prepared_xids > 0);
  if (--prepared_xids == 0)
    pthread_cond_signal(&COND_prep_xids);
  pthread_mutex_unlock(&LOCK_prep_xids);
  rotate_and_purge(0);     // as ::write() did not rotate
}

int TC_LOG_BINLOG::recover(IO_CACHE *log, Format_description_log_event *fdle)
{
  Log_event  *ev;
  HASH xids;
  MEM_ROOT mem_root;

  if (! fdle->is_valid() ||
      hash_init(&xids, &my_charset_bin, TC_LOG_PAGE_SIZE/3, 0,
            sizeof(my_xid), 0, 0, MYF(0)))
    goto err1;

  init_alloc_root(&mem_root, TC_LOG_PAGE_SIZE, TC_LOG_PAGE_SIZE);

  fdle->flags&= ~LOG_EVENT_BINLOG_IN_USE_F; // abort on the first error

  while ((ev= Log_event::read_log_event(log,0,fdle)) && ev->is_valid())
  {
    if (ev->get_type_code() == XID_EVENT)
    {
      Xid_log_event *xev=(Xid_log_event *)ev;
      byte *x=(byte *)memdup_root(&mem_root, (char *)& xev->xid,
                                  sizeof(xev->xid));
      if (! x)
        goto err2;
      my_hash_insert(&xids, x);
    }
    delete ev;
  }

  if (ha_recover(&xids))
    goto err2;

  free_root(&mem_root, MYF(0));
  hash_free(&xids);
  return 0;

err2:
  free_root(&mem_root, MYF(0));
  hash_free(&xids);
err1:
  sql_print_error("Crash recovery failed. Either correct the problem "
                  "(if it's, for example, out of memory error) and restart, "
                  "or delete (or rename) binary log and start mysqld with "
                  "--tc-heuristic-recover={commit|rollback}");
  return 1;
}

struct st_mysql_storage_engine binlog_storage_engine=
{ MYSQL_HANDLERTON_INTERFACE_VERSION };

mysql_declare_plugin(binlog)
{
  MYSQL_STORAGE_ENGINE_PLUGIN,
  &binlog_storage_engine,
  "binlog",
  "MySQL AB",
  "This is a pseudo storage engine to represent the binlog in a transaction",
  PLUGIN_LICENSE_GPL,
  binlog_init, /* Plugin Init */
  NULL, /* Plugin Deinit */
  0x0100 /* 1.0 */,
  NULL,                       /* status variables                */
  NULL,                       /* system variables                */
  NULL                        /* config options                  */
}
mysql_declare_plugin_end;