/* Database access routines
   Copyright (C) 1996, William M. Perry

This file is part of XEmacs.

XEmacs 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; either version 2, or (at your option) any
later version.

XEmacs 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 XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* Written by Bill Perry */
/* Substantially rewritten by Martin Buchholz */
/* db 2.x support added by Andreas Jaeger */

#include <config.h>
#include "lisp.h"
#include "sysfile.h"
#include <errno.h>

#ifndef HAVE_DATABASE
#error HAVE_DATABASE not defined!!
#endif

#include "database.h"         /* Our include file */

#ifdef HAVE_BERKELEY_DB
/* Work around Berkeley DB's use of int types which are defined
   slightly differently in the not quite yet standard <inttypes.h>.
   See db.h for details of why we're resorting to this... */
/* glibc 2.1 doesn't have this problem with DB 2.x */
#if !(defined __GLIBC__ && __GLIBC_MINOR__ >= 1)
#ifdef HAVE_INTTYPES_H
#define __BIT_TYPES_DEFINED__
#include <inttypes.h>
typedef uint8_t  u_int8_t;
typedef uint16_t u_int16_t;
typedef uint32_t u_int32_t;
#ifdef WE_DONT_NEED_QUADS
typedef uint64_t u_int64_t;
#endif /* WE_DONT_NEED_QUADS */
#endif /* HAVE_INTTYPES_H */
#endif /* !(defined __GLIBC__ && __GLIBC_MINOR__ >= 1) */
#include DB_H_PATH              /* Berkeley db's header file */
#ifndef DB_VERSION_MAJOR
# define DB_VERSION_MAJOR 1
#endif /* DB_VERSION_MAJOR */
Lisp_Object Qberkeley_db;
Lisp_Object Qhash, Qbtree, Qrecno, Qunknown;
#endif /* HAVE_BERKELEY_DB */

#ifdef HAVE_DBM
#include <ndbm.h>
Lisp_Object Qdbm;
#endif /* HAVE_DBM */

Lisp_Object Qdatabasep;

typedef enum { DB_DBM, DB_BERKELEY, DB_IS_UNKNOWN } XEMACS_DB_TYPE;

struct Lisp_Database;

typedef struct
{
  Lisp_Object (*get_subtype) (struct Lisp_Database *);
  Lisp_Object (*get_type) (struct Lisp_Database *);
  Lisp_Object (*get) (struct Lisp_Database *, Lisp_Object);
  int (*put) (struct Lisp_Database *, Lisp_Object, Lisp_Object, Lisp_Object);
  int (*rem) (struct Lisp_Database *, Lisp_Object);
  void (*map) (struct Lisp_Database *, Lisp_Object);
  void (*close) (struct Lisp_Database *);
  Lisp_Object (*last_error) (struct Lisp_Database *);
} DB_FUNCS;

struct Lisp_Database
{
  struct lcrecord_header header;
  Lisp_Object fname;
  XEMACS_DB_TYPE type;
  int mode;
  int access_;
  int dberrno;
  int live_p;
#ifdef HAVE_DBM
  DBM *dbm_handle;
#endif
#ifdef HAVE_BERKELEY_DB
  DB *db_handle;
#endif
  DB_FUNCS *funcs;
#ifdef MULE
  Lisp_Object coding_system;
#endif
};

#define XDATABASE(x) XRECORD (x, database, struct Lisp_Database)
#define XSETDATABASE(x, p) XSETRECORD (x, p, database)
#define DATABASEP(x) RECORDP (x, database)
#define GC_DATABASEP(x) GC_RECORDP (x, database)
#define CHECK_DATABASE(x) CHECK_RECORD (x, database)
#define CONCHECK_DATABASE(x) CONCHECK_RECORD (x, database)
#define DATABASE_LIVE_P(x) (x->live_p)

#define CHECK_LIVE_DATABASE(db) do {					\
  CHECK_DATABASE (db);							\
  if (!DATABASE_LIVE_P (XDATABASE(db)))					\
    signal_simple_error ("Attempting to access closed database", db);	\
} while (0)


static struct Lisp_Database *
allocate_database (void)
{
  struct Lisp_Database *db =
    alloc_lcrecord_type (struct Lisp_Database, lrecord_database);

  db->fname = Qnil;
  db->live_p = 0;
#ifdef HAVE_BERKELEY_DB
  db->db_handle = NULL;
#endif
#ifdef HAVE_DBM
  db->dbm_handle = NULL;
#endif
  db->access_ = 0;
  db->mode = 0;
  db->dberrno = 0;
  db->type = DB_IS_UNKNOWN;
#ifdef MULE
  db->coding_system = Fget_coding_system (Qbinary);
#endif
  return db;
}

static Lisp_Object
mark_database (Lisp_Object obj, void (*markobj) (Lisp_Object))
{
  struct Lisp_Database *db = XDATABASE (obj);

  ((markobj) (db->fname));
  return Qnil;
}

static void
print_database (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
{
  char buf[64];
  struct Lisp_Database *db = XDATABASE (obj);

  if (print_readably)
    error ("printing unreadable object #<database 0x%x>", db->header.uid);

  write_c_string ("#<database \"", printcharfun);
  print_internal (db->fname, printcharfun, 0);
  sprintf (buf, "\" (%s/%s/%s) 0x%x>",
	   (char *) string_data (XSYMBOL (db->funcs->get_type (db))->name),
	   (char *) string_data (XSYMBOL (db->funcs->get_subtype (db))->name),
	   (!DATABASE_LIVE_P (db)    ? "closed"    :
	    (db->access_ & O_WRONLY) ? "writeonly" :
	    (db->access_ & O_RDWR)   ? "readwrite" : "readonly"),
	   db->header.uid);
  write_c_string (buf, printcharfun);
}

static void
finalize_database (void *header, int for_disksave)
{
  struct Lisp_Database *db = (struct Lisp_Database *) header;

  if (for_disksave)
    {
      Lisp_Object obj;
      XSETOBJ (obj, Lisp_Type_Record, (void *) db);

      signal_simple_error
	("Can't dump an emacs containing database objects", obj);
    }
  db->funcs->close (db);
}

DEFINE_LRECORD_IMPLEMENTATION ("database", database,
                               mark_database, print_database,
			       finalize_database, 0, 0,
			       struct Lisp_Database);

DEFUN ("close-database", Fclose_database, 1, 1, 0, /*
Close database DATABASE.
*/
       (database))
{
  struct Lisp_Database *db;
  CHECK_LIVE_DATABASE (database);
  db = XDATABASE (database);
  db->funcs->close (db);
  db->live_p = 0;
  return Qnil;
}

DEFUN ("database-type", Fdatabase_type, 1, 1, 0, /*
Return the type of database DATABASE.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->get_type (XDATABASE (database));
}

DEFUN ("database-subtype", Fdatabase_subtype, 1, 1, 0, /*
Return the subtype of database DATABASE, if any.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->get_subtype (XDATABASE (database));
}

DEFUN ("database-live-p", Fdatabase_live_p, 1, 1, 0, /*
Return t if OBJ is an active database.
*/
       (obj))
{
  return DATABASEP (obj) && DATABASE_LIVE_P (XDATABASE (obj)) ? Qt : Qnil;
}

DEFUN ("database-file-name", Fdatabase_file_name, 1, 1, 0, /*
Return the filename associated with the database DATABASE.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->fname;
}

DEFUN ("databasep", Fdatabasep, 1, 1, 0, /*
Return t if OBJ is a database.
*/
       (obj))
{
  return DATABASEP (obj) ? Qt : Qnil;
}

#ifdef HAVE_DBM
static void
dbm_map (struct Lisp_Database *db, Lisp_Object func)
{
  datum keydatum, valdatum;
  Lisp_Object key, val;

  for (keydatum = dbm_firstkey (db->dbm_handle);
       keydatum.dptr != NULL;
       keydatum = dbm_nextkey (db->dbm_handle))
    {
      valdatum = dbm_fetch (db->dbm_handle, keydatum);
      key = make_string ((unsigned char *) keydatum.dptr, keydatum.dsize);
      val = make_string ((unsigned char *) valdatum.dptr, valdatum.dsize);
      call2 (func, key, val);
    }
}

static Lisp_Object
dbm_get (struct Lisp_Database *db, Lisp_Object key)
{
  datum keydatum, valdatum;

  keydatum.dptr = (char *) XSTRING_DATA (key);
  keydatum.dsize = XSTRING_LENGTH (key);
  valdatum = dbm_fetch (db->dbm_handle, keydatum);

  return (valdatum.dptr
	  ? make_string ((unsigned char *) valdatum.dptr, valdatum.dsize)
	  : Qnil);
}

static int
dbm_put (struct Lisp_Database *db,
	 Lisp_Object key, Lisp_Object val, Lisp_Object replace)
{
  datum keydatum, valdatum;

  valdatum.dptr = (char *) XSTRING_DATA (val);
  valdatum.dsize = XSTRING_LENGTH (val);
  keydatum.dptr = (char *) XSTRING_DATA (key);
  keydatum.dsize = XSTRING_LENGTH (key);

  return !dbm_store (db->dbm_handle, keydatum, valdatum,
		     NILP (replace) ? DBM_INSERT : DBM_REPLACE);
}

static int
dbm_remove (struct Lisp_Database *db, Lisp_Object key)
{
  datum keydatum;

  keydatum.dptr = (char *) XSTRING_DATA (key);
  keydatum.dsize = XSTRING_LENGTH (key);

  return dbm_delete (db->dbm_handle, keydatum);
}

static Lisp_Object
dbm_type (struct Lisp_Database *db)
{
  return Qdbm;
}

static Lisp_Object
dbm_subtype (struct Lisp_Database *db)
{
  return Qnil;
}

static Lisp_Object
dbm_lasterr (struct Lisp_Database *db)
{
  return lisp_strerror (db->dberrno);
}

static void
dbm_closeit (struct Lisp_Database *db)
{
  if (db->dbm_handle)
    {
      dbm_close (db->dbm_handle);
      db->dbm_handle = NULL;
    }
}

static DB_FUNCS ndbm_func_block =
{
  dbm_subtype,
  dbm_type,
  dbm_get,
  dbm_put,
  dbm_remove,
  dbm_map,
  dbm_closeit,
  dbm_lasterr
};
#endif /* HAVE_DBM */

#ifdef HAVE_BERKELEY_DB
static Lisp_Object
berkdb_type (struct Lisp_Database *db)
{
  return Qberkeley_db;
}

static Lisp_Object
berkdb_subtype (struct Lisp_Database *db)
{
  if (!db->db_handle)
    return Qnil;

  switch (db->db_handle->type)
    {
    case DB_BTREE: return Qbtree;
    case DB_HASH:  return Qhash;
    case DB_RECNO: return Qrecno;
    default:       return Qunknown;
    }
}

static Lisp_Object
berkdb_lasterr (struct Lisp_Database *db)
{
  return lisp_strerror (db->dberrno);
}

static Lisp_Object
berkdb_get (struct Lisp_Database *db, Lisp_Object key)
{
  /* #### Needs mule-izing */
  DBT keydatum, valdatum;
  int status = 0;

#if DB_VERSION_MAJOR == 2
  /* Always initialize keydatum, valdatum. */
  xzero (keydatum);
  xzero (valdatum);
#endif /* DV_VERSION_MAJOR = 2 */

  keydatum.data = XSTRING_DATA (key);
  keydatum.size = XSTRING_LENGTH (key);

#if DB_VERSION_MAJOR == 1
  status = db->db_handle->get (db->db_handle, &keydatum, &valdatum, 0);
#else
  status = db->db_handle->get (db->db_handle, NULL, &keydatum, &valdatum, 0);
#endif /* DB_VERSION_MAJOR */

  if (!status)
    return make_string ((Bufbyte *) valdatum.data, valdatum.size);

#if DB_VERSION_MAJOR == 1
  db->dberrno = (status == 1) ? -1 : errno;
#else
  db->dberrno = (status < 0) ? -1 : errno;
#endif /* DB_VERSION_MAJOR */

  return Qnil;
}

static int
berkdb_put (struct Lisp_Database *db,
	    Lisp_Object key,
	    Lisp_Object val,
	    Lisp_Object replace)
{
  DBT keydatum, valdatum;
  int status = 0;

#if DB_VERSION_MAJOR == 2
  /* Always initalize keydatum, valdatum. */
  xzero (keydatum);
  xzero (valdatum);
#endif /* DV_VERSION_MAJOR = 2 */

  keydatum.data = XSTRING_DATA   (key);
  keydatum.size = XSTRING_LENGTH (key);
  valdatum.data = XSTRING_DATA   (val);
  valdatum.size = XSTRING_LENGTH (val);
#if DB_VERSION_MAJOR == 1
  status = db->db_handle->put (db->db_handle, &keydatum, &valdatum,
 			       NILP (replace) ? R_NOOVERWRITE : 0);
  db->dberrno = (status == 1) ? -1 : errno;
#else
  status = db->db_handle->put (db->db_handle, NULL, &keydatum, &valdatum,
			       NILP (replace) ? DB_NOOVERWRITE : 0);
  db->dberrno = (status < 0) ? -1 : errno;
#endif/* DV_VERSION_MAJOR = 2 */

  return status;
}

static int
berkdb_remove (struct Lisp_Database *db, Lisp_Object key)
{
  DBT keydatum;
  int status;

#if DB_VERSION_MAJOR == 2
  /* Always initialize keydatum. */
  xzero (keydatum);
#endif /* DV_VERSION_MAJOR = 2 */

  keydatum.data = XSTRING_DATA   (key);
  keydatum.size = XSTRING_LENGTH (key);

#if DB_VERSION_MAJOR == 1
  status = db->db_handle->del (db->db_handle, &keydatum, 0);
#else
  status = db->db_handle->del (db->db_handle, NULL, &keydatum, 0);
#endif /* DB_VERSION_MAJOR */

  if (!status)
    return 0;

#if DB_VERSION_MAJOR == 1
  db->dberrno = (status == 1) ? -1 : errno;
#else
  db->dberrno = (status < 0) ? -1 : errno;
#endif /* DB_VERSION_MAJOR */

  return 1;
}

static void
berkdb_map (struct Lisp_Database *db, Lisp_Object func)
{
  DBT keydatum, valdatum;
  Lisp_Object key, val;
  DB *dbp = db->db_handle;
  int status;

#if DB_VERSION_MAJOR == 1
  for (status = dbp->seq (dbp, &keydatum, &valdatum, R_FIRST);
       status == 0;
       status = dbp->seq (dbp, &keydatum, &valdatum, R_NEXT))
    {
      /* ### Needs mule-izing */
      key = make_string ((Bufbyte *) keydatum.data, keydatum.size);
      val = make_string ((Bufbyte *) valdatum.data, valdatum.size);
      call2 (func, key, val);
    }
#else
  DBC *dbcp;
  /* Initialize the key/data pair so the flags aren't set. */
  xzero (keydatum);
  xzero (valdatum);

#if DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >=6
  status = dbp->cursor (dbp, NULL, &dbcp, 0);
#else
  status = dbp->cursor (dbp, NULL, &dbcp);
#endif
  for (status = dbcp->c_get (dbcp, &keydatum, &valdatum, DB_FIRST);
       status == 0;
       status = dbcp->c_get (dbcp, &keydatum, &valdatum, DB_NEXT))
    {
      /* ### Needs mule-izing */
      key = make_string ((Bufbyte *) keydatum.data, keydatum.size);
      val = make_string ((Bufbyte *) valdatum.data, valdatum.size);
      call2 (func, key, val);
    }
  dbcp->c_close (dbcp);
#endif /* DB_VERSION_MAJOR */
}

static void
berkdb_close (struct Lisp_Database *db)
{
  if (db->db_handle)
    {
#if DB_VERSION_MAJOR == 1
      db->db_handle->sync  (db->db_handle, 0);
      db->db_handle->close (db->db_handle);
#else
      db->db_handle->sync  (db->db_handle, 0);
      db->db_handle->close (db->db_handle, 0);
#endif /* DB_VERSION_MAJOR */
      db->db_handle = NULL;
    }
}

static DB_FUNCS berk_func_block =
{
  berkdb_subtype,
  berkdb_type,
  berkdb_get,
  berkdb_put,
  berkdb_remove,
  berkdb_map,
  berkdb_close,
  berkdb_lasterr
};
#endif /* HAVE_BERKELEY_DB */

DEFUN ("database-last-error", Fdatabase_last_error, 0, 1, 0, /*
Return the last error associated with DATABASE.
*/
       (database))
{
  if (NILP (database))
    return lisp_strerror (errno);

  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->last_error (XDATABASE (database));
}

DEFUN ("open-database", Fopen_database, 1, 5, 0, /*
Return a new database object opened on FILE.
Optional arguments TYPE and SUBTYPE specify the database type.
Optional argument ACCESS specifies the access rights, which may be any
combination of 'r' 'w' and '+', for read, write, and creation flags.
Optional argument MODE gives the permissions to use when opening FILE,
and defaults to 0755.
*/
       (file, type, subtype, access_, mode))
{
  /* This function can GC */
  int modemask;
  int accessmask = 0;
  struct Lisp_Database *db = NULL;
  char *filename;
  struct gcpro gcpro1, gcpro2;

  CHECK_STRING (file);
  GCPRO2 (file, access_);
  file = Fexpand_file_name (file, Qnil);
  UNGCPRO;
  filename = (char *) XSTRING_DATA (file);

  if (NILP (access_))
    {
      accessmask = O_RDWR | O_CREAT;
    }
  else
    {
      char *acc;
      CHECK_STRING (access_);
      acc = (char *) XSTRING_DATA (access_);

      if (strchr (acc, '+'))
	accessmask |= O_CREAT;

      {
	char *rp = strchr (acc, 'r');
	char *wp = strchr (acc, 'w');
	if (rp && wp) accessmask |= O_RDWR;
	else if (wp)  accessmask |= O_WRONLY;
	else          accessmask |= O_RDONLY;
      }
    }

  if (NILP (mode))
    {
      modemask = 0755;		/* rwxr-xr-x */
    }
  else
    {
      CHECK_INT (mode);
      modemask = XINT (mode);
    }

#ifdef HAVE_DBM
  if (NILP (type) || EQ (type, Qdbm))
    {
      DBM *dbase = dbm_open (filename, accessmask, modemask);
      if (!dbase)
	return Qnil;

      db = allocate_database ();
      db->dbm_handle = dbase;
      db->type = DB_DBM;
      db->funcs = &ndbm_func_block;
      goto db_done;
    }
#endif /* HAVE_DBM */

#ifdef HAVE_BERKELEY_DB
  if (NILP (type) || EQ (type, Qberkeley_db))
    {
      DBTYPE real_subtype;
      DB *dbase;
#if DB_VERSION_MAJOR != 1
      int status;
#endif

      if (EQ (subtype, Qhash) || NILP (subtype))
	real_subtype = DB_HASH;
      else if (EQ (subtype, Qbtree))
	real_subtype = DB_BTREE;
      else if (EQ (subtype, Qrecno))
	real_subtype = DB_RECNO;
      else
	signal_simple_error ("Unsupported subtype", subtype);

#if DB_VERSION_MAJOR == 1
      dbase = dbopen (filename, accessmask, modemask, real_subtype, NULL);
      if (!dbase)
	return Qnil;
#else
      /* Berkeley DB Version 2 has only the accessmask DB_CREATE and DB_RDONLY,
	 other flags shouldn't be set */
      if (NILP (access_))
	accessmask = DB_CREATE;
      else
	{
	  char *acc;
	  CHECK_STRING (access_);
	  acc = (char *) XSTRING_DATA (access_);
	  accessmask = 0;

	  if (strchr (acc, '+'))
	    accessmask |= DB_CREATE;

	  if (strchr (acc, 'r') && !strchr (acc, 'w'))
	    accessmask |= DB_RDONLY;
	}
      status = db_open (filename, real_subtype, accessmask,
			modemask, NULL , NULL, &dbase);
      if (status)
	return Qnil;
#endif /* DB_VERSION_MAJOR */

      db = allocate_database ();
      db->db_handle = dbase;
      db->type = DB_BERKELEY;
      db->funcs = &berk_func_block;
      goto db_done;
    }
#endif /* HAVE_BERKELEY_DB */

  signal_simple_error ("Unsupported database type", type);
  return Qnil;

 db_done:
  db->live_p = 1;
  db->fname = file;
  db->mode = modemask;
  db->access_ = accessmask;

  {
    Lisp_Object retval;
    XSETDATABASE (retval, db);
    return retval;
  }
}

DEFUN ("put-database", Fput_database, 3, 4, 0, /*
Store KEY and VALUE in DATABASE.
If optional fourth arg REPLACE is non-nil,
replace any existing entry in the database.
*/
       (key, value, database, replace))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  CHECK_STRING (value);
  {
    struct Lisp_Database *db = XDATABASE (database);
    int status = db->funcs->put (db, key, value, replace);
    return status ? Qt : Qnil;
  }
}

DEFUN ("remove-database", Fremove_database, 2, 2, 0, /*
Remove KEY from DATABASE.
*/
       (key, database))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  {
    struct Lisp_Database *db = XDATABASE (database);
    int status = db->funcs->rem (db, key);
    return status ? Qt : Qnil;
  }
}

DEFUN ("get-database", Fget_database, 2, 3, 0, /*
Return value for KEY in DATABASE.
If there is no corresponding value, return DEFAULT (defaults to nil).
*/
       (key, database, default_))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  {
    struct Lisp_Database *db = XDATABASE (database);
    Lisp_Object retval = db->funcs->get (db, key);
    return NILP (retval) ? default_ : retval;
  }
}

DEFUN ("map-database", Fmapdatabase, 2, 2, 0, /*
Map FUNCTION over entries in DATABASE, calling it with two args,
each key and value in the database.
*/
       (function, database))
{
  CHECK_LIVE_DATABASE (database);

  XDATABASE (database)->funcs->map (XDATABASE (database), function);

  return Qnil;
}

void
syms_of_database (void)
{
  defsymbol (&Qdatabasep, "databasep");
#ifdef HAVE_DBM
  defsymbol (&Qdbm, "dbm");
#endif
#ifdef HAVE_BERKELEY_DB
  defsymbol (&Qberkeley_db, "berkeley-db");
  defsymbol (&Qhash, "hash");
  defsymbol (&Qbtree, "btree");
  defsymbol (&Qrecno, "recno");
  defsymbol (&Qunknown, "unknown");
#endif

  DEFSUBR (Fopen_database);
  DEFSUBR (Fdatabasep);
  DEFSUBR (Fmapdatabase);
  DEFSUBR (Fput_database);
  DEFSUBR (Fget_database);
  DEFSUBR (Fremove_database);
  DEFSUBR (Fdatabase_type);
  DEFSUBR (Fdatabase_subtype);
  DEFSUBR (Fdatabase_last_error);
  DEFSUBR (Fdatabase_live_p);
  DEFSUBR (Fdatabase_file_name);
  DEFSUBR (Fclose_database);
}

void
vars_of_database (void)
{
#ifdef HAVE_DBM
  Fprovide (Qdbm);
#endif
#ifdef HAVE_BERKELEY_DB
  Fprovide (Qberkeley_db);
#endif
}
