~drizzle-trunk/drizzle/development

/* 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 */

#include <drizzled/server_includes.h>

#include "rpl_mi.h"

#ifdef HAVE_REPLICATION

#define DEFAULT_CONNECT_RETRY 60

// Defined in slave.cc

int init_intvar_from_file(int* var, IO_CACHE* f, int default_val);

int init_strvar_from_file(char *var, int max_size, IO_CACHE *f,

			  const char *default_val);

int init_floatvar_from_file(float* var, IO_CACHE* f, float default_val);

Master_info::Master_info()

  :Slave_reporting_capability("I/O"),

   ssl(0), ssl_verify_server_cert(0), fd(-1),  io_thd(0), port(DRIZZLE_PORT),

   connect_retry(DEFAULT_CONNECT_RETRY), heartbeat_period(0),

   received_heartbeats(0), inited(0),

   abort_slave(0), slave_running(0), slave_run_id(0)

{

  host[0] = 0; user[0] = 0; password[0] = 0;

  ssl_ca[0]= 0; ssl_capath[0]= 0; ssl_cert[0]= 0;

  ssl_cipher[0]= 0; ssl_key[0]= 0;

  memset(&file, 0, sizeof(file));

  pthread_mutex_init(&run_lock, MY_MUTEX_INIT_FAST);

  pthread_mutex_init(&data_lock, MY_MUTEX_INIT_FAST);

  pthread_cond_init(&data_cond, NULL);

  pthread_cond_init(&start_cond, NULL);

  pthread_cond_init(&stop_cond, NULL);

}

Master_info::~Master_info()

{

  pthread_mutex_destroy(&run_lock);

  pthread_mutex_destroy(&data_lock);

  pthread_cond_destroy(&data_cond);

  pthread_cond_destroy(&start_cond);

  pthread_cond_destroy(&stop_cond);

}

void init_master_log_pos(Master_info* mi)

{

  mi->master_log_name[0] = 0;

  mi->master_log_pos = BIN_LOG_HEADER_SIZE;             // skip magic number

  /* 

    always request heartbeat unless master_heartbeat_period is set

    explicitly zero.  Here is the default value for heartbeat period

    if CHANGE MASTER did not specify it.  (no data loss in conversion

    as hb period has a max)

  */

  mi->heartbeat_period= (float) min((double)SLAVE_MAX_HEARTBEAT_PERIOD,

                                    (slave_net_timeout/2.0));

  assert(mi->heartbeat_period > (float) 0.001

              || mi->heartbeat_period == 0);

  return;

}

enum {

  LINES_IN_MASTER_INFO_WITH_SSL= 14,

  /* 5.1.16 added value of master_ssl_verify_server_cert */

  LINE_FOR_MASTER_SSL_VERIFY_SERVER_CERT= 15,

  /* 6.0 added value of master_heartbeat_period */

  LINE_FOR_MASTER_HEARTBEAT_PERIOD= 16,

  /* Number of lines currently used when saving master info file */

  LINES_IN_MASTER_INFO= LINE_FOR_MASTER_HEARTBEAT_PERIOD

};

int init_master_info(Master_info* mi, const char* master_info_fname,

                     const char* slave_info_fname,

                     bool abort_if_no_master_info_file,

                     int thread_mask)

{

  int fd,error;

  char fname[FN_REFLEN+128];

  if (mi->inited)

  {

    /*

      We have to reset read position of relay-log-bin as we may have

      already been reading from 'hotlog' when the slave was stopped

      last time. If this case pos_in_file would be set and we would

      get a crash when trying to read the signature for the binary

      relay log.

      We only rewind the read position if we are starting the SQL

      thread. The handle_slave_sql thread assumes that the read

      position is at the beginning of the file, and will read the

      "signature" and then fast-forward to the last position read.

    */

    if (thread_mask & SLAVE_SQL)

    {

      my_b_seek(mi->rli.cur_log, (my_off_t) 0);

    }

    return(0);

  }

  mi->drizzle=0;

  mi->file_id=1;

  fn_format(fname, master_info_fname, mysql_data_home, "", 4+32);

  /*

    We need a mutex while we are changing master info parameters to

    keep other threads from reading bogus info

  */

  pthread_mutex_lock(&mi->data_lock);

  fd = mi->fd;

  /* does master.info exist ? */

  if (access(fname,F_OK))

  {

    if (abort_if_no_master_info_file)

    {

      pthread_mutex_unlock(&mi->data_lock);

      return(0);

    }

    /*

      if someone removed the file from underneath our feet, just close

      the old descriptor and re-create the old file

    */

    if (fd >= 0)

      my_close(fd, MYF(MY_WME));

    if ((fd = my_open(fname, O_CREAT|O_RDWR|O_BINARY, MYF(MY_WME))) < 0 )

    {

      sql_print_error(_("Failed to create a new master info file (file '%s', errno %d)"), fname, my_errno);

      goto err;

    }

    if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,0,

                      MYF(MY_WME)))

    {

      sql_print_error(_("Failed to create a cache on master info file (file '%s')"), fname);

      goto err;

    }

    mi->fd = fd;

    init_master_log_pos(mi);

  }

  else // file exists

  {

    if (fd >= 0)

      reinit_io_cache(&mi->file, READ_CACHE, 0L,0,0);

    else

    {

      if ((fd = my_open(fname, O_RDWR|O_BINARY, MYF(MY_WME))) < 0 )

      {

        sql_print_error(_("Failed to open the existing master info file (file '%s', errno %d)"), fname, my_errno);

        goto err;

      }

      if (init_io_cache(&mi->file, fd, IO_SIZE*2, READ_CACHE, 0L,

                        0, MYF(MY_WME)))

      {

        sql_print_error(_("Failed to create a cache on master info file (file '%s')"), fname);

        goto err;

      }

    }

    mi->fd = fd;

    int port, connect_retry, master_log_pos, lines;

    int ssl= 0, ssl_verify_server_cert= 0;

    float master_heartbeat_period= 0.0;

    char *first_non_digit;

    /*

       Starting from 4.1.x master.info has new format. Now its

       first line contains number of lines in file. By reading this

       number we will be always distinguish to which version our

       master.info corresponds to. We can't simply count lines in

       file since versions before 4.1.x could generate files with more

       lines than needed.

       If first line doesn't contain a number or contain number less than

       LINES_IN_MASTER_INFO_WITH_SSL then such file is treated like file

       from pre 4.1.1 version.

       There is no ambiguity when reading an old master.info, as before

       4.1.1, the first line contained the binlog's name, which is either

       empty or has an extension (contains a '.'), so can't be confused

       with an integer.

       So we're just reading first line and trying to figure which version

       is this.

    */

    /*

       The first row is temporarily stored in mi->master_log_name,

       if it is line count and not binlog name (new format) it will be

       overwritten by the second row later.

    */

    if (init_strvar_from_file(mi->master_log_name,

                              sizeof(mi->master_log_name), &mi->file,

                              ""))

      goto errwithmsg;

    lines= strtoul(mi->master_log_name, &first_non_digit, 10);

    if (mi->master_log_name[0]!='\0' &&

        *first_non_digit=='\0' && lines >= LINES_IN_MASTER_INFO_WITH_SSL)

    {

      /* Seems to be new format => read master log name from next line */

      if (init_strvar_from_file(mi->master_log_name,

            sizeof(mi->master_log_name), &mi->file, ""))

        goto errwithmsg;

    }

    else

      lines= 7;

    if (init_intvar_from_file(&master_log_pos, &mi->file, 4) ||

        init_strvar_from_file(mi->host, sizeof(mi->host), &mi->file, 0) ||

        init_strvar_from_file(mi->user, sizeof(mi->user), &mi->file, "test") ||

        init_strvar_from_file(mi->password, SCRAMBLED_PASSWORD_CHAR_LENGTH+1,

                              &mi->file, 0 ) ||

        init_intvar_from_file(&port, &mi->file, DRIZZLE_PORT) ||

        init_intvar_from_file(&connect_retry, &mi->file, DEFAULT_CONNECT_RETRY))

      goto errwithmsg;

    /*

      If file has ssl part use it even if we have server without

      SSL support. But these option will be ignored later when

      slave will try connect to master, so in this case warning

      is printed.

    */

    if (lines >= LINES_IN_MASTER_INFO_WITH_SSL)

    {

      if (init_intvar_from_file(&ssl, &mi->file, 0) ||

          init_strvar_from_file(mi->ssl_ca, sizeof(mi->ssl_ca),

                                &mi->file, 0) ||

          init_strvar_from_file(mi->ssl_capath, sizeof(mi->ssl_capath),

                                &mi->file, 0) ||

          init_strvar_from_file(mi->ssl_cert, sizeof(mi->ssl_cert),

                                &mi->file, 0) ||

          init_strvar_from_file(mi->ssl_cipher, sizeof(mi->ssl_cipher),

                                &mi->file, 0) ||

          init_strvar_from_file(mi->ssl_key, sizeof(mi->ssl_key),

                               &mi->file, 0))

      goto errwithmsg;

      /*

        Starting from 5.1.16 ssl_verify_server_cert might be

        in the file

      */

      if (lines >= LINE_FOR_MASTER_SSL_VERIFY_SERVER_CERT &&

          init_intvar_from_file(&ssl_verify_server_cert, &mi->file, 0))

        goto errwithmsg;

      /*

        Starting from 6.0 master_heartbeat_period might be

        in the file

      */

      if (lines >= LINE_FOR_MASTER_HEARTBEAT_PERIOD &&

          init_floatvar_from_file(&master_heartbeat_period, &mi->file, 0.0))

        goto errwithmsg;

    }

    if (ssl)

      sql_print_warning(_("SSL information in the master info file "

                          "('%s') are ignored because this MySQL slave was "

                          "compiled without SSL support."), fname);

    /*

      This has to be handled here as init_intvar_from_file can't handle

      my_off_t types

    */

    mi->master_log_pos= (my_off_t) master_log_pos;

    mi->port= (uint) port;

    mi->connect_retry= (uint) connect_retry;

    mi->ssl= (bool) ssl;

    mi->ssl_verify_server_cert= ssl_verify_server_cert;

    mi->heartbeat_period= master_heartbeat_period;

  }

  mi->rli.mi = mi;

  if (init_relay_log_info(&mi->rli, slave_info_fname))

    goto err;

  mi->inited = 1;

  // now change cache READ -> WRITE - must do this before flush_master_info

  reinit_io_cache(&mi->file, WRITE_CACHE, 0L, 0, 1);

  if ((error=test(flush_master_info(mi, 1))))

    sql_print_error(_("Failed to flush master info file"));

  pthread_mutex_unlock(&mi->data_lock);

  return(error);

errwithmsg:

  sql_print_error(_("Error reading master configuration"));

err:

  if (fd >= 0)

  {

    my_close(fd, MYF(0));

    end_io_cache(&mi->file);

  }

  mi->fd= -1;

  pthread_mutex_unlock(&mi->data_lock);

  return(1);

}

/*

  RETURN

     2 - flush relay log failed

     1 - flush master info failed

     0 - all ok

*/

int flush_master_info(Master_info* mi, bool flush_relay_log_cache)

{

  IO_CACHE* file = &mi->file;

  char lbuf[22];

  /*

    Flush the relay log to disk. If we don't do it, then the relay log while

    have some part (its last kilobytes) in memory only, so if the slave server

    dies now, with, say, from master's position 100 to 150 in memory only (not

    on disk), and with position 150 in master.info, then when the slave

    restarts, the I/O thread will fetch binlogs from 150, so in the relay log

    we will have "[0, 100] U [150, infinity[" and nobody will notice it, so the

    SQL thread will jump from 100 to 150, and replication will silently break.

    When we come to this place in code, relay log may or not be initialized;

    the caller is responsible for setting 'flush_relay_log_cache' accordingly.

  */

  if (flush_relay_log_cache &&

      flush_io_cache(mi->rli.relay_log.get_log_file()))

    return(2);

  /*

    We flushed the relay log BEFORE the master.info file, because if we crash

    now, we will get a duplicate event in the relay log at restart. If we

    flushed in the other order, we would get a hole in the relay log.

    And duplicate is better than hole (with a duplicate, in later versions we

    can add detection and scrap one event; with a hole there's nothing we can

    do).

  */

  /*

     In certain cases this code may create master.info files that seems

     corrupted, because of extra lines filled with garbage in the end

     file (this happens if new contents take less space than previous

     contents of file). But because of number of lines in the first line

     of file we don't care about this garbage.

  */

  char heartbeat_buf[sizeof(mi->heartbeat_period) * 4]; // buffer to suffice always

  sprintf(heartbeat_buf, "%.3f", mi->heartbeat_period);

  my_b_seek(file, 0L);

  my_b_printf(file,

              "%u\n%s\n%s\n%s\n%s\n%s\n%d\n%d\n%d\n%s\n%s\n%s\n%s\n%s\n%d\n%s\n",

              LINES_IN_MASTER_INFO,

              mi->master_log_name, llstr(mi->master_log_pos, lbuf),

              mi->host, mi->user,

              mi->password, mi->port, mi->connect_retry,

              (int)(mi->ssl), mi->ssl_ca, mi->ssl_capath, mi->ssl_cert,

              mi->ssl_cipher, mi->ssl_key, mi->ssl_verify_server_cert,

              heartbeat_buf);

  return(-flush_io_cache(file));

}

void end_master_info(Master_info* mi)

{

  if (!mi->inited)

    return;

  end_relay_log_info(&mi->rli);

  if (mi->fd >= 0)

  {

    end_io_cache(&mi->file);

    (void)my_close(mi->fd, MYF(MY_WME));

    mi->fd = -1;

  }

  mi->inited = 0;

  return;

}

#endif /* HAVE_REPLICATION */