/* database.c -- database module.

   Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012

     National Institute of Advanced Industrial Science and Technology (AIST)

     Registration Number H15PRO112

   This file is part of the m17n library.

   The m17n library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public License

   as published by the Free Software Foundation; either version 2.1 of

   the License, or (at your option) any later version.

   The m17n library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the m17n library; if not, write to the Free

   Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

   Boston, MA 02110-1301 USA.  */

/***en

    @addtogroup m17nDatabase

    @brief The m17n database and API for it.

    The m17n library acquires various kinds of information

    from data in the  m17n database on demand.  Application

    programs can also add/load their original data to/from the m17n

    database by setting the variable #mdatabase_dir to an

    application-specific directory and storing data in it.  Users can

    overwrite those data by storing preferable data in the directory

    specified by the environment variable "M17NDIR", or if it is not

    set, in the directory "~/.m17n.d".

    The m17n database contains multiple heterogeneous data, and each

    data is identified by four tags; TAG0, TAG1, TAG2, TAG3.  Each tag

    must be a symbol.

    TAG0 specifies the type of data stored in the database as below.

    @li

    If TAG0 is #Mchar_table, the data is of the @e chartable @e

    type and provides information about each character.  In this case,

    TAG1 specifies the type of the information and must be #Msymbol,

    #Minteger, #Mstring, #Mtext, or #Mplist.  TAG2 and TAG3 can be any

    symbols.

    @li

    If TAG0 is #Mcharset, the data is of the @e charset @e type

    and provides a decode/encode mapping table for a charset.  In this

    case, TAG1 must be a symbol representing a charset.  TAG2 and TAG3

    can be any symbols.

    @li 

    If TAG0 is neither #Mchar_table nor #Mcharset, the data is of

    the @e plist @e type.  See the documentation of the 

    mdatabase_load () function for the details.  

    In this case, TAG1, TAG2, and TAG3 can be any symbols.

    The notation \<TAG0, TAG1, TAG2, TAG3\> means a data with those

    tags.

    Application programs first calls the mdatabase_find () function to

    get a pointer to an object of the type #MDatabase.  That object

    holds information about the specified data.  When it is

    successfully returned, the mdatabase_load () function loads the

    data.  The implementation of the structure #MDatabase is

    concealed from application programs.

*/

/***ja

    @addtogroup m17nDatabase

    @brief m17n データベースにとそれに関する API.

    m17n ライブラリは必要に応じて動的に @e m17n @e データベース 

    から情報を取得する。またアプリケーションプログラムも、独自のデータを 

    m17n データベースに追加し、それを動的に取得することができる。

    アプリケーションプログラムが独自のデータを追加・取得するには、変数 

    #mdatabase_dir にそのアプリケーション固有のディレクトリをセットし、

    その中にデータを格納する。ユーザがそのデータをオーバーライトしたい

    ときは、環境変数 "M17NDIR" で指定されるディレクトリ（指定されていな

    いときは "~/.m17n.d" というディレクトリ）に別のデータを置く。

    m17n 

    データベースには複数の多様なデータが含まれており、各データは

    TAG0, TAG1, TAG2, TAG3（すべてシンボル）の４つのタグによって識別される。

    TAG0 によって、データベース内のデータのタイプは次のように指定される。

    @li 

    TAG0 が #Mchar_table であるデータは @e chartableタイプ 

    と呼ばれ、各文字に関する情報を提供する。この場合

    TAG1 は情報の種類を指定するシンボルであり、#Msymbol, #Minteger, #Mstring,

    #Mtext, #Mplist のいずれかである。TAG2 と TAG3 は任意のシンボルでよい。

    @li 

    TAG0 が #Mcharset であるデータは @e charsetタイプ 

    と呼ばれ、文字セット用のデコード／エンコードマップを提供する。この場合 TAG1

    は文字セットのシンボルでなければならない。TAG2 と TAG3

    は任意のシンボルでよい。

    @li

    TAG0 が #Mchar_table でも #Mcharset でもない場合、そのデータは @e

    plistタイプ である。詳細に関しては関数 mdatabase_load () 

    の説明を参照のこと。この場合 TAG1、TAG2、TAG3 は任意のシンボルでよい。

    特定のタグを持つデータベースを \<TAG0, TAG1, TAG2, TAG3\> 

    という形式で表す。

    アプリケーションプログラムは、まず関数 mdatabase_find () 

    を使ってデータベースに関する情報を保持するオブジェクト（#MDatabase

    型）へのポインタを得る。それに成功したら、 mdatabase_load () 

    によって実際にデータベースをロードする。構造体 #MDatabase 

    自身がどう実装されているかは、アプリケーションプログラムからは見えない。

    @latexonly \IPAlabel{database} @endlatexonly

*/

/*=*/

#if !defined (FOR_DOXYGEN) || defined (DOXYGEN_INTERNAL_MODULE)

/*** @addtogroup m17nInternal

     @{ */

#include <config.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <unistd.h>

#include <limits.h>

#include <glob.h>

#include <time.h>

#include <libgen.h>

#include "m17n-core.h"

#include "m17n-misc.h"

#include "internal.h"

#include "mtext.h"

#include "character.h"

#include "database.h"

#include "plist.h"

/** The file containing a list of databases.  */

#define MDB_DIR "mdb.dir"

/** Length of MDB_DIR.  */

#define MDB_DIR_LEN 7

#define MAX_TIME(TIME1, TIME2) ((TIME1) >= (TIME2) ? (TIME1) : (TIME2))

#define GEN_PATH(path, dir, dir_len, file, file_len)	\

  (dir_len + file_len > PATH_MAX ? 0			\

   : (memcpy (path, dir, dir_len),			\

      memcpy (path + dir_len, file, file_len),		\

      path[dir_len + file_len] = '\0', 1))

static MSymbol Masterisk;

static MSymbol Mversion;

/** Structure for a data in the m17n database.  */

struct MDatabase

{

  /** Tags to identify the data.  <tag>[0] specifies the type of

      database.  If it is #Mchar_table, the type is @e chartable, if

      it is #Mcharset, the type is @e charset, otherwise the type is

      @e plist.  */

  MSymbol tag[4];

  void *(*loader) (MSymbol *tags, void *extra_info);

  /** The meaning of the value is dependent on <loader>.  If <loader>

      is load_database (), the value is a string of the file name that

      contains the data.  */

  void *extra_info;

};

static MPlist *mdatabase__list;

static int

read_number (char *buf, int *i)

{

  int idx = *i;

  int c = buf[idx++];

  int n;

  if (!c)

    return -1;

  while (c && isspace (c)) c = buf[idx++];

  if (c == '0')

    {

      if (buf[idx] == 'x')

	{

	  for (idx++, c = 0; (n = hex_mnemonic[(unsigned) buf[idx]]) < 16;

	       idx++)

	    c  = (c << 4) | n;

	  *i = idx;

	  return c;

	}

      c = 0;

    }

  else if (c == '\'')

    {

      c = buf[idx++];

      if (c == '\\')

	{

	  c = buf[idx++];

	  n = escape_mnemonic[c];

	  if (n != 255)

	    c = n;

	}

      while (buf[idx] && buf[idx++] != '\'');

      *i = idx;

      return c;

    }

  else if (hex_mnemonic[c] < 10)

    c -= '0';

  else

    return -1;

  while ((n = hex_mnemonic[(unsigned) buf[idx]]) < 10)

    c = (c * 10) + n, idx++;

  *i = idx;

  return c;

}

/** Load a data of type @c chartable from the file FD, and return the

    newly created chartable.  */

static void *

load_chartable (FILE *fp, MSymbol type)

{

  int c, from, to;

  char buf[1024];

  void *val;

  MCharTable *table;

  if (! fp)

    MERROR (MERROR_DB, NULL);

  table = mchartable (type, (type == Msymbol ? (void *) Mnil

			     : type == Minteger ? (void *) -1

			     : NULL));

  while (! feof (fp))

    {

      int i, len;

      for (len = 0; len < 1023 && (c = getc (fp)) != EOF && c != '\n'; len++)

	buf[len] = c;

      buf[len] = '\0';	  

      if (hex_mnemonic[(unsigned) buf[0]] >= 10)

	/* skip comment/invalid line */

	continue;

      i = 0;

      from = read_number (buf, &i);

      if (buf[i] == '-')

	i++, to = read_number (buf, &i);

      else

	to = from;

      if (from < 0 || to < from)

	continue;

      while (buf[i] && isspace ((unsigned) buf[i])) i++;

      c = buf[i];

      if (!c)

	continue;

      if (type == Mstring)

	{

	  /* VAL is a C-string.  */

	  if (! (val = strdup (buf + i)))

	    MEMORY_FULL (MERROR_DB);

	}

      else if (type == Minteger)

	{

	  /* VAL is an integer.  */

	  int positive = 1;

	  int n;

	  if (c == '-')

	    i++, positive = -1;

	  n = read_number (buf, &i);

	  if (n < 0)

	    goto label_error;

	  val = (void *) (n * positive);

	}

      else if (type == Mtext)

	{

	  /* VAL is an M-text.  */

	  MText *mt;

	  if (c == '"')

	    mt = mtext__from_data (buf + i, len - i - 1, MTEXT_FORMAT_UTF_8, 1);

	  else

	    {

	      mt = mtext ();

	      while ((c = read_number (buf, &i)) >= 0)

		mt = mtext_cat_char (mt, c);

	    }

	  val = (void *) mt;

	}

      else if (type == Msymbol)

	{

	  char *p = buf + i;

	  while (*p && ! isspace (*p)) 

	    {

	      if (*p == '\\' && p[1] != '\0')

		{

		  memmove (p, p + 1, buf + len - (p + 1));

		  len--;

		}

	      p++;

	    }

	  *p = '\0';

	  if (! strcmp (buf + i, "nil"))

	    val = (void *) Mnil;

	  else

	    val = (void *) msymbol (buf + i);

	}

      else if (type == Mplist)

	{

	  val = (void *) mplist__from_string ((unsigned char *) buf + i,

					      strlen (buf + i));

	}

      else

	val = NULL;

      if (from == to)

	mchartable_set (table, from, val);

      else

	mchartable_set_range (table, from, to, val);

    }

  return table;

 label_error:

  M17N_OBJECT_UNREF (table);

  MERROR (MERROR_DB, NULL);

}

static char *

gen_database_name (char *buf, MSymbol *tags)

{

  int i;

  strcpy (buf, msymbol_name (tags[0]));

  for (i = 1; i < 4; i++)

    {

      strcat (buf, ",");

      strcat (buf, msymbol_name (tags[i]));

    }

  return buf;

}

/* Return the absolute file name for DB_INFO->filename or NULL if no

   absolute file name was found.  If BUF is non-NULL, store the result

   of `stat' call in it.  In that case, set *RESULT to the return

   value of `stat'.  */

char *

get_database_file (MDatabaseInfo *db_info, struct stat *buf, int *result)

{

  if (db_info->absolute_filename)

    {

      if (buf)

	*result = stat (db_info->absolute_filename, buf);

    }

  else

    {

      struct stat stat_buf;

      struct stat *statbuf = buf ? buf : &stat_buf;

      int res;

      MPlist *plist;

      char path[PATH_MAX + 1];

      MPLIST_DO (plist, mdatabase__dir_list)

	{

	  MDatabaseInfo *dir_info = MPLIST_VAL (plist);

	  if (dir_info->status != MDB_STATUS_DISABLED

	      && GEN_PATH (path, dir_info->filename, dir_info->len,

			   db_info->filename, db_info->len)

	      && (res = stat (path, statbuf)) == 0)

	    {

	      db_info->absolute_filename = strdup (path);

	      if (result)

		*result = res;

	      break;

	    }

	}

    }

  return db_info->absolute_filename;

}

static void *

load_database (MSymbol *tags, void *extra_info)

{

  MDatabaseInfo *db_info = extra_info;

  void *value;

  char *filename = get_database_file (db_info, NULL, NULL);

  FILE *fp;

  int mdebug_flag = MDEBUG_DATABASE;

  char buf[256];

  MDEBUG_PRINT1 (" [DB] <%s>", gen_database_name (buf, tags));

  if (! filename || ! (fp = fopen (filename, "r")))

    {

      if (filename)

	MDEBUG_PRINT1 (" open fail: %s\n", filename);

      else

	MDEBUG_PRINT1 (" not found: %s\n", db_info->filename);

      MERROR (MERROR_DB, NULL);

    }

  MDEBUG_PRINT1 (" from %s\n", filename);

  if (tags[0] == Mchar_table)

    value = load_chartable (fp, tags[1]);

  else if (tags[0] == Mcharset)

    {

      if (! mdatabase__load_charset_func)

	MERROR (MERROR_DB, NULL);

      value = (*mdatabase__load_charset_func) (fp, tags[1]);

    }

  else

    value = mplist__from_file (fp, NULL);

  fclose (fp);

  if (! value)

    MERROR (MERROR_DB, NULL);

  db_info->time = time (NULL);

  return value;

}

/** Return a newly allocated MDatabaseInfo for DIRNAME.  */

static MDatabaseInfo *

get_dir_info (char *dirname)

{

  MDatabaseInfo *dir_info;

  MSTRUCT_CALLOC (dir_info, MERROR_DB);

  if (dirname)

    {

      int len = strlen (dirname);

      if (len + MDB_DIR_LEN < PATH_MAX)

	{

	  MTABLE_MALLOC (dir_info->filename, len + 2, MERROR_DB);

	  memcpy (dir_info->filename, dirname, len + 1);

	  /* Append PATH_SEPARATOR if DIRNAME doesn't end with it.  */

	  if (dir_info->filename[len - 1] != PATH_SEPARATOR)

	    {

	      dir_info->filename[len] = PATH_SEPARATOR;

	      dir_info->filename[++len] = '\0';

	    }

	  dir_info->len = len;

	  dir_info->status = MDB_STATUS_OUTDATED;

	}

      else

	dir_info->status = MDB_STATUS_DISABLED;	

    }

  else

    dir_info->status = MDB_STATUS_DISABLED;

  return dir_info;

}

static void register_databases_in_files (MSymbol tags[4],

					 char *filename, int len);

static MDatabase *

find_database (MSymbol tags[4])

{

  MPlist *plist;

  int i;

  MDatabase *mdb;

  if (! mdatabase__list)

    return NULL;

  for (i = 0, plist = mdatabase__list; i < 4; i++)

    {

      MPlist *pl = mplist__assq (plist, tags[i]);

      MPlist *p;

      if ((p = mplist__assq (plist, Masterisk)))

	{

	  MDatabaseInfo *db_info;

	  int j;

	  p = MPLIST_PLIST (p);

	  for (j = i + 1; j < 4; j++)

	    p = MPLIST_PLIST (MPLIST_NEXT (p));

	  mdb = MPLIST_VAL (MPLIST_NEXT (p));

	  db_info = mdb->extra_info;

	  if (db_info->status != MDB_STATUS_DISABLED)

	    {

	      register_databases_in_files (mdb->tag,

					   db_info->filename, db_info->len);

	      db_info->status = MDB_STATUS_DISABLED;

	      return find_database (tags);

	    }

	}

      if (! pl)

	return NULL;

      plist = MPLIST_PLIST (pl);

      plist = MPLIST_NEXT (plist);

    }

  mdb = MPLIST_VAL (plist);

  return mdb;

}

static void

free_db_info (MDatabaseInfo *db_info)

{

  free (db_info->filename);

  if (db_info->absolute_filename

      && db_info->filename != db_info->absolute_filename)

    free (db_info->absolute_filename);

  M17N_OBJECT_UNREF (db_info->properties);

  free (db_info);

}

static int

check_version (MText *version)

{

  char *verstr = (char *) MTEXT_DATA (version);

  char *endp = verstr + mtext_nbytes (version);

  int ver[3];

  int i;

  ver[0] = ver[1] = ver[2] = 0;

  for (i = 0; verstr < endp; verstr++)

    {

      if (*verstr == '.')

	{

	  i++;

	  if (i == 3)

	    break;

	  continue;

	}

      if (! isdigit (*verstr))

	break;

      ver[i] = ver[i] * 10 + (*verstr - '0');

    }

  return (ver[0] < M17NLIB_MAJOR_VERSION

	  || (ver[0] == M17NLIB_MAJOR_VERSION

	      && (ver[1] < M17NLIB_MINOR_VERSION

		  || (ver[1] == M17NLIB_MINOR_VERSION

		      && ver[2] <= M17NLIB_PATCH_LEVEL))));

}

static MDatabase *

register_database (MSymbol tags[4],

		   void *(*loader) (MSymbol *, void *),

		   void *extra_info, enum MDatabaseStatus status,

		   MPlist *properties)

{

  MDatabase *mdb;

  MDatabaseInfo *db_info;

  int i;

  MPlist *plist;

  if (properties)

    {

      MPLIST_DO (plist, properties)

	if (MPLIST_PLIST_P (plist))

	  {

	    MPlist *p = MPLIST_PLIST (plist);

	    if (MPLIST_SYMBOL_P (p)

		&& MPLIST_SYMBOL (p) == Mversion

		&& MPLIST_MTEXT_P (MPLIST_NEXT (p)))

	      {

		if (check_version (MPLIST_MTEXT (MPLIST_NEXT (p))))

		  break;

		return NULL;

	      }

	  }

    }

  for (i = 0, plist = mdatabase__list; i < 4; i++)

    {

      MPlist *pl = mplist__assq (plist, tags[i]);

      if (pl)

	pl = MPLIST_PLIST (pl);

      else

	{

	  pl = mplist ();

	  mplist_add (pl, Msymbol, tags[i]);

	  mplist_push (plist, Mplist, pl);

	  M17N_OBJECT_UNREF (pl);

	}

      plist = MPLIST_NEXT (pl);

    }

  if (MPLIST_TAIL_P (plist))

    {

      MSTRUCT_MALLOC (mdb, MERROR_DB);

      for (i = 0; i < 4; i++)

	mdb->tag[i] = tags[i];

      mdb->loader = loader;

      if (loader == load_database)

	{

	  MSTRUCT_CALLOC (db_info, MERROR_DB);

	  mdb->extra_info = db_info;

	}

      else

	{

	  db_info = NULL;

	  mdb->extra_info = extra_info;

	}

      mplist_push (plist, Mt, mdb);

    }

  else

    {

      mdb = MPLIST_VAL (plist);

      if (loader == load_database)

	db_info = mdb->extra_info;

      else

	db_info = NULL;

    }

  if (db_info)

    {

      db_info->status = status;

      if (! db_info->filename

	  || strcmp (db_info->filename, (char *) extra_info) != 0)

	{

	  if (db_info->filename)

	    free (db_info->filename);

	  if (db_info->absolute_filename

	      && db_info->filename != db_info->absolute_filename)

	    free (db_info->absolute_filename);

	  db_info->filename = strdup ((char *) extra_info);

	  db_info->len = strlen ((char *) extra_info);

	  db_info->time = 0;

	}

      if (db_info->filename[0] == PATH_SEPARATOR)

	db_info->absolute_filename = db_info->filename;

      else

	db_info->absolute_filename = NULL;

      M17N_OBJECT_UNREF (db_info->properties);

      if (properties)

	{

	  db_info->properties = properties;

	  M17N_OBJECT_REF (properties);

	}

    }

  if (mdb->tag[0] == Mchar_table

      && mdb->tag[2] != Mnil

      && (mdb->tag[1] == Mstring || mdb->tag[1] == Mtext

	  || mdb->tag[1] == Msymbol || mdb->tag[1] == Minteger

	  || mdb->tag[1] == Mplist))

    mchar__define_prop (mdb->tag[2], mdb->tag[1], mdb);

  return mdb;

}

static void

register_databases_in_files (MSymbol tags[4], char *filename, int len)

{

  int i, j;

  MPlist *load_key = mplist ();

  FILE *fp;

  MPlist *plist, *pl;

  MPLIST_DO (plist, mdatabase__dir_list)

    {

      glob_t globbuf;

      int headlen;

      if (filename[0] == PATH_SEPARATOR)

	{

	  if (glob (filename, GLOB_NOSORT, NULL, &globbuf))

	    break;

	  headlen = 0;

	}

      else

	{

	  MDatabaseInfo *d_info = MPLIST_VAL (plist);

	  char path[PATH_MAX + 1];

	  if (d_info->status == MDB_STATUS_DISABLED)

	    continue;

	  if (! GEN_PATH (path, d_info->filename, d_info->len, filename, len))

	    continue;

	  if (glob (path, GLOB_NOSORT, NULL, &globbuf))

	    continue;

	  headlen = d_info->len;

	}

      for (i = 0; i < globbuf.gl_pathc; i++)

	{

	  if (! (fp = fopen (globbuf.gl_pathv[i], "r")))

	    continue;

	  pl = mplist__from_file (fp, load_key);

	  fclose (fp);

	  if (! pl)

	    continue;

	  if (MPLIST_PLIST_P (pl))

	    {

	      MPlist *p;

	      MSymbol tags2[4];

	      for (j = 0, p = MPLIST_PLIST (pl); j < 4 && MPLIST_SYMBOL_P (p);

		   j++, p = MPLIST_NEXT (p))

		tags2[j] = MPLIST_SYMBOL (p);

	      for (; j < 4; j++)

		tags2[j] = Mnil;

	      for (j = 0; j < 4; j++)

		if (tags[j] != Masterisk && tags[j] != tags2[j])

		  break;

	      if (j == 4)

		register_database (tags2, load_database,

				   globbuf.gl_pathv[i] + headlen,

				   MDB_STATUS_AUTO, p);

	    }

	  M17N_OBJECT_UNREF (pl);

	}

      globfree (&globbuf);

      if (filename[0] == PATH_SEPARATOR)

	break;

    }

  M17N_OBJECT_UNREF (load_key);

}

static int

expand_wildcard_database (MPlist *plist)

{

  MDatabase *mdb;

  MDatabaseInfo *db_info;

  plist = MPLIST_NEXT (plist);

  while (MPLIST_PLIST_P (plist))

    {

      plist = MPLIST_PLIST (plist);

      plist = MPLIST_NEXT (plist);

    }

  mdb = MPLIST_VAL (plist);

  if (mdb->loader == load_database

      && (db_info = mdb->extra_info)

      && db_info->status != MDB_STATUS_DISABLED)

    {

      register_databases_in_files (mdb->tag, db_info->filename, db_info->len);

      db_info->status = MDB_STATUS_DISABLED;

      return 1;

    }

  return 0;

}

/* Internal API */

/** List of database directories.  */ 

MPlist *mdatabase__dir_list;

void *(*mdatabase__load_charset_func) (FILE *fp, MSymbol charset_name);

int

mdatabase__init ()

{

  MDatabaseInfo *dir_info;

  char *path;

  mdatabase__load_charset_func = NULL;

  Mchar_table = msymbol ("char-table");

  Mcharset = msymbol ("charset");

  Masterisk = msymbol ("*");

  Mversion = msymbol ("version");

  mdatabase__dir_list = mplist ();

  /** The macro M17NDIR specifies a directory where the system-wide

    MDB_DIR file exists.  */

  mplist_set (mdatabase__dir_list, Mt, get_dir_info (M17NDIR));

  /* The variable mdatabase_dir specifies a directory where an

     application program specific MDB_DIR file exists.  */

  if (mdatabase_dir && strlen (mdatabase_dir) > 0)

    mplist_push (mdatabase__dir_list, Mt, get_dir_info (mdatabase_dir));

  /* The environment variable M17NDIR specifies a directory where a

     user specific MDB_DIR file exists.  */

  path = getenv ("M17NDIR");

  if (path && strlen (path) > 0)

    mplist_push (mdatabase__dir_list, Mt, get_dir_info (path));

  else

    {

      /* If the env var M17NDIR is not set, check "~/.m17n.d".  */

      char *home = getenv ("HOME");

      int len;

      if (home

	  && (len = strlen (home))

	  && (path = alloca (len + 9)))

	{

	  strcpy (path, home);

	  if (path[len - 1] != PATH_SEPARATOR)

	    path[len++] = PATH_SEPARATOR;

	  strcpy (path + len, ".m17n.d");

	  dir_info = get_dir_info (path);

	  mplist_push (mdatabase__dir_list, Mt, dir_info);

	}

      else

	mplist_push (mdatabase__dir_list, Mt, get_dir_info (NULL));

    }

  mdatabase__list = mplist ();

  mdatabase__update ();

  return 0;

}

void

mdatabase__fini (void)

{

  MPlist *plist, *p0, *p1, *p2, *p3;

  MPLIST_DO (plist, mdatabase__dir_list)

    free_db_info (MPLIST_VAL (plist));

  M17N_OBJECT_UNREF (mdatabase__dir_list);

  /* MDATABASE_LIST ::= ((TAG0 (TAG1 (TAG2 (TAG3 t:MDB) ...) ...) ...) ...) */

  MPLIST_DO (plist, mdatabase__list)

    {

      p0 = MPLIST_PLIST (plist);

      /* P0 ::= (TAG0 (TAG1 (TAG2 (TAG3 t:MDB) ...) ...) ...) */

      MPLIST_DO (p0, MPLIST_NEXT (p0))

	{

	  p1 = MPLIST_PLIST (p0);

	  /* P1 ::= (TAG1 (TAG2 (TAG3 t:MDB) ...) ...) */

	  MPLIST_DO (p1, MPLIST_NEXT (p1))

	    {

	      p2 = MPLIST_PLIST (p1);

	      /* P2 ::= (TAG2 (TAG3 t:MDB) ...) */

	      MPLIST_DO (p2, MPLIST_NEXT (p2))

		{

		  MDatabase *mdb;

		  p3 = MPLIST_PLIST (p2); /* P3 ::= (TAG3 t:MDB) */

		  p3 = MPLIST_NEXT (p3);

		  mdb = MPLIST_VAL (p3);

		  if (mdb->loader == load_database)

		    free_db_info (mdb->extra_info);

		  free (mdb);

		}

	    }

	}

    }

  M17N_OBJECT_UNREF (mdatabase__list);

}

void

mdatabase__update (void)

{

  MPlist *plist, *p0, *p1, *p2, *p3;

  char path[PATH_MAX + 1];

  MDatabaseInfo *dir_info;

  struct stat statbuf;

  int rescan = 0;

  /* Update elements of mdatabase__dir_list.  */

  MPLIST_DO (plist, mdatabase__dir_list)

    {

      dir_info = MPLIST_VAL (plist);

      if (dir_info->filename)

	{

	  if (stat (dir_info->filename, &statbuf) == 0

	      && (statbuf.st_mode & S_IFDIR))

	    {

	      if (dir_info->time < statbuf.st_mtime)