mariadb/sql/log_cache.cc

#include "my_global.h"
#include "log_cache.h"
#include "handler.h"
#include "my_sys.h"
#include "mysql/psi/mysql_file.h"
#include "mysql/service_wsrep.h"

const char *BINLOG_CACHE_DIR= "#binlog_cache_files";
char binlog_cache_dir[FN_REFLEN];
extern uint32 binlog_cache_reserved_size();

bool binlog_cache_data::init_file_reserved_bytes()
{
  // Session's cache file is not created, so created here.
  if (cache_log.file == -1)
  {
    char name[FN_REFLEN];

    /* Cache file is named with PREFIX + binlog_cache_data object's address */
    snprintf(name, FN_REFLEN, "%s/%s_%llu", cache_log.dir, cache_log.prefix,
             (ulonglong) this);

    if ((cache_log.file=
             mysql_file_open(0, name, O_CREAT | O_RDWR, MYF(MY_WME))) < 0)
    {
      sql_print_error("Failed to open binlog cache temporary file %s", name);
      cache_log.error= -1;
      return true;
    }
  }

#ifdef WITH_WSREP
  /*
    WSREP code accesses cache_log directly, so don't reserve space if WSREP is
    on.
  */
  if (unlikely(wsrep_on(current_thd)))
    return false;
#endif

  m_file_reserved_bytes= binlog_cache_reserved_size();
  cache_log.pos_in_file= m_file_reserved_bytes;
  cache_log.seek_not_done= 1;
  return false;
}

void binlog_cache_data::detach_temp_file()
{
  mysql_file_close(cache_log.file, MYF(0));
  cache_log.file= -1;
  reset();
}

extern void ignore_db_dirs_append(const char *dirname_arg);

bool init_binlog_cache_dir()
{
  size_t length;
  uint max_tmp_file_name_len=
      2 /* prefix */ + 10 /* max len of thread_id */ + 1 /* underline */;

  /*
    Even if the binary log is disabled, or implemented in a storage engine
    (--binlog-storage-engine), and thereby we wouldn't use the binlog cache
    dir, we need to try to build the directory name, so if it exists (e.g.
    due to a previous run of mariadbd, or an SST from a server with a file
    binlog), we can delete it.
  */
  const bool use_cache_dir= opt_bin_log && !opt_binlog_engine_hton;
  dirname_part(binlog_cache_dir,
               use_cache_dir ? log_bin_basename : opt_log_basename, &length);
  /*
    Must ensure the full name of the tmp file is shorter than FN_REFLEN, to
    avoid overflowing the name buffer in write and commit.
  */
  if (length + strlen(BINLOG_CACHE_DIR) + max_tmp_file_name_len >= FN_REFLEN)
  {
    sql_print_error("Could not create binlog cache dir %s%s. It is too long.",
                    binlog_cache_dir, BINLOG_CACHE_DIR);
    return true;
  }

  memcpy(binlog_cache_dir + length, BINLOG_CACHE_DIR,
         strlen(BINLOG_CACHE_DIR));
  binlog_cache_dir[length + strlen(BINLOG_CACHE_DIR)]= 0;

  MY_DIR *dir_info= my_dir(binlog_cache_dir, MYF(0));

  /*
    If the binlog cache dir exists, yet it is not used, delete the
    directory and skip the initialization logic.
  */
  if (!use_cache_dir)
  {
    if (dir_info)
    {
      sql_print_information(
          "Found binlog cache dir '%s', yet binary logging is %s. "
          "Deleting directory.",
          binlog_cache_dir,
          opt_bin_log ? "implemented in a storage engine" : "disabled");
      my_dirend(dir_info);
      my_rmtree(binlog_cache_dir, MYF(0));
    }
    memset(binlog_cache_dir, 0, sizeof(binlog_cache_dir));
    return false;
  }

  ignore_db_dirs_append(BINLOG_CACHE_DIR);

  if (!dir_info)
  {
    /* Make a dir for binlog cache temp files if not exist. */
    if (my_mkdir(binlog_cache_dir, 0777, MYF(0)) < 0)
    {
      sql_print_error("Could not create binlog cache dir %s.",
                      binlog_cache_dir);
      return true;
    }
    return false;
  }

  /* Try to delete all cache files in the directory. */
  for (uint i= 0; i < dir_info->number_of_files; i++)
  {
    FILEINFO *file= dir_info->dir_entry + i;

    if (strncmp(file->name, LOG_PREFIX, strlen(LOG_PREFIX)))
    {
      sql_print_warning("%s is in %s/, but it is not a binlog cache file",
                        file->name, BINLOG_CACHE_DIR);
      continue;
    }

    char file_path[FN_REFLEN];
    fn_format(file_path, file->name, binlog_cache_dir, "",
              MYF(MY_REPLACE_DIR));

    my_delete(file_path, MYF(0));
  }

  my_dirend(dir_info);
  return false;
}