Deliantra-Client/DC/DB.pm

=head1 NAME

DC::DB - async. database and filesystem access for deliantra

=head1 SYNOPSIS

 use DC::DB;

=head1 DESCRIPTION

=over 4

=cut

package DC::DB;

use strict;
use utf8;

use File::Path ();
use Carp ();
use Storable ();
use Config;
use BDB;

use DC;

our $ODBDIR  = "cfplus-" . BDB::VERSION . "-$Config{archname}";
our $DBDIR   = "client-" . BDB::VERSION . "-$Config{archname}";
our $DB_HOME = "$Deliantra::VARDIR/$DBDIR";

unless (-d $DB_HOME) {
   if (-d "$Deliantra::VARDIR/$ODBDIR") {
      rename "$Deliantra::VARDIR/$ODBDIR", $DB_HOME;
      print STDERR "INFO: moved old database from $Deliantra::VARDIR/$ODBDIR to $DB_HOME\n";
   } elsif (-d "$Deliantra::OLDDIR/$ODBDIR") {
      rename "$Deliantra::OLDDIR/$DBDIR", $DB_HOME;
      print STDERR "INFO: moved old database from $Deliantra::OLDDIR/$ODBDIR to $DB_HOME\n";
   } else {
      File::Path::mkpath [$DB_HOME]
         or die "unable to create database directory $DB_HOME: $!";
   }
}

BDB::max_poll_time 0.03;
BDB::max_parallel 1;

our $DB_ENV;
our $DB_STATE;
our %DB_TABLE;
our $TILE_SEQ;

sub try_open_db {
   File::Path::mkpath [$DB_HOME];

   my $env = db_env_create;

   $env->set_errfile (\*STDERR);
   $env->set_msgfile (\*STDERR);
   $env->set_verbose (-1, 1);

   $env->set_flags (BDB::AUTO_COMMIT | BDB::LOG_AUTOREMOVE | BDB::TXN_WRITE_NOSYNC);
   $env->set_cachesize (0, 2048 * 1024, 0);

   db_env_open $env, $DB_HOME,
               BDB::CREATE | BDB::REGISTER | BDB::RECOVER | BDB::INIT_MPOOL | BDB::INIT_LOCK | BDB::INIT_TXN,
               0666;

   $! and die "cannot open database environment $DB_HOME: " . BDB::strerror;

   $DB_ENV = $env;

   1
}

sub table($) {
   $DB_TABLE{$_[0]} ||= do {
      my ($table) = @_;

      $table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;

      my $db = db_create $DB_ENV;
      $db->set_flags (BDB::CHKSUM);

      db_open $db, undef, $table, undef, BDB::BTREE,
              BDB::AUTO_COMMIT | BDB::CREATE | BDB::READ_UNCOMMITTED, 0666;

      $! and "unable to open/create database table $_[0]: ". BDB::strerror;

      $db
   }
}

#############################################################################

our $WATCHER;
our $SYNC;
our $facemap;

sub exists($$$) {
   my ($db, $key, $cb) = @_;

   my $data;
   db_get table $db, undef, $key, $data, 0, sub {
      $cb->($! ? () : length $data);
   };
}

sub get($$$) {
   my ($db, $key, $cb) = @_;

   my $data;
   db_get table $db, undef, $key, $data, 0, sub {
      $cb->($! ? () : $data);
   };
}

sub put($$$$) {
   my ($db, $key, $data, $cb) = @_;

   db_put table $db, undef, $key, $data, 0, sub {
      $cb->($!);
      $SYNC->again unless $SYNC->is_active;
   };
}

sub do_table {
   my ($db, $cb) = @_;

   $db = table $db;

   my $cursor = $db->cursor;
   my %kv;

   for (;;) {
      db_c_get $cursor, my $k, my $v, BDB::NEXT;
      last if $!;
      $kv{$k} = $v;
   }

   $cb->(\%kv);
}

sub do_get_tile_id {
   my ($name, $cb) = @_;

   my $table = table "facemap";
   my $id;

   db_get $table, undef, $name => $id, 0;
   $! or return $cb->($id);

   unless ($TILE_SEQ) {
      $TILE_SEQ = $table->sequence;
      $TILE_SEQ->initial_value (64);
      $TILE_SEQ->set_cachesize (0);
      db_sequence_open $TILE_SEQ, undef, "id", BDB::CREATE;
   }

   db_sequence_get $TILE_SEQ, undef, 1, my $id;

   die "unable to allocate tile id: $!"
      if $!;
   
   db_put $table, undef, $name => $id, 0;
   $cb->($id);

}

sub get_tile_id_sync($) {
   my ($name) = @_;

   $facemap->{$name} ||= do {
      my $id;
      do_get_tile_id $name, sub {
         $id = $_[0];
      };
      BDB::flush;
      $id
   }
}

#############################################################################

sub path_of_res($) {
   utf8::downgrade $_[0]; # bug in unpack "H*"
   "$DB_HOME/res-data-" . unpack "H*", $_[0]
}

sub sync {
   # for debugging
   #DC::DB::Server::req (sync => sub { });
   DC::DB::Server::sync ();
}

sub unlink($$) {
   DC::DB::Server::req (unlink => @_);
}

sub read_file($$) {
   DC::DB::Server::req (read_file => @_);
}

sub write_file($$$) {
   DC::DB::Server::req (write_file => @_);
}

sub prefetch_file($$$) {
   DC::DB::Server::req (prefetch_file => @_);
}

sub logprint($$$) {
   DC::DB::Server::req (logprint => @_);
}

#############################################################################

package DC::DB::Server;

use strict;

use EV ();
use Fcntl;

our %CB;
our $FH;
our $ID = "aaa0";
our ($fh_r_watcher, $fh_w_watcher);
our $sync_timer;
our $write_buf;
our $read_buf;

sub fh_write {
   my $len = syswrite $FH, $write_buf;

   substr $write_buf, 0, $len, "";

   $fh_w_watcher->stop
      unless length $write_buf;
}

sub fh_read {
   my $status = sysread $FH, $read_buf, 16384, length $read_buf;

   die "FATAL: database process died\n"
      if $status == 0 && defined $status;

   while () {
      return if 4 > length $read_buf;
      my $len = unpack "N", $read_buf;

      return if $len + 4 > length $read_buf;

      substr $read_buf, 0, 4, "";
      my $res = Storable::thaw substr $read_buf, 0, $len, "";

      my ($id, @args) = @$res;
      (delete $CB{$id})->(@args);
   }
}

sub sync {
   # biggest mess evarr
   my $fds; (vec $fds, fileno $FH, 1) =  1;

   while (1 < scalar keys %CB) {
      my $r = $fds;
      my $w = length $write_buf ? $fds : undef;
      select $r, $w, undef, undef;

      fh_write if vec $w, fileno $FH, 1;
      fh_read  if vec $r, fileno $FH, 1;
   }
}

sub req {
   my ($type, @args) = @_;
   my $cb = pop @args;

   my $id = ++$ID;
   $write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
   $CB{$id} = $cb;

   $fh_w_watcher->start;
}

sub do_unlink {
   unlink $_[0];
}

sub do_read_file {
   my ($path) = @_;

   utf8::downgrade $path;
   open my $fh, "<:raw", $path
      or return;
   sysread $fh, my $buf, -s $fh;

   $buf
}

sub do_write_file {
   my ($path, $data) = @_;

   utf8::downgrade $path;
   utf8::downgrade $data;
   open my $fh, ">:raw", $path
      or return;
   syswrite $fh, $data;
   close $fh;

   1
}

sub do_prefetch_file {
   my ($path, $size) = @_;

   utf8::downgrade $path;
   open my $fh, "<:raw", $path
      or return;
   sysread $fh, my $buf, $size;

   1
}

our %LOG_FH;

sub do_logprint {
   my ($path, $line) = @_;

   $LOG_FH{$path} ||= do {
      open my $fh, ">>:utf8", $path
         or warn "Couldn't open logfile $path: $!";

      $fh->autoflush (1);

      $fh
   };

   my ($sec, $min, $hour, $mday, $mon, $year) = localtime time;

   my $ts = sprintf "%04d-%02d-%02d %02d:%02d:%02d",
               $year + 1900, $mon + 1, $mday, $hour, $min, $sec;

   print { $LOG_FH{$path} } "$ts $line\n"
}

sub run {
   ($FH, my $fh) = DC::socketpipe;

   my $oldfh = select $FH; $| = 1; select $oldfh;
   my $oldfh = select $fh; $| = 1; select $oldfh;

   my $pid = fork;
   
   if (defined $pid && !$pid) {
      local $SIG{QUIT} = "IGNORE";
      local $SIG{__DIE__};
      local $SIG{__WARN__};
      eval {
         close $FH;

         while () {
            4 == read $fh, my $len, 4
               or last;
            $len = unpack "N", $len;
            $len == read $fh, my $req, $len
               or die "unexpected eof while reading request";

            $req = Storable::thaw $req;

            my ($id, $type, @args) = @$req;
            my $cb = DC::DB::Server->can ("do_$type")
               or die "$type: unknown database request type\n";
            my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
            (syswrite $fh, $res) == length $res
               or die "DB::write: $!";
         }
      };

      my $error = $@;

      eval {
         Storable::store_fd [die => $error], $fh;
      };

      warn $error
         if $error;

      DC::_exit 0;
   }

   close $fh;
   DC::fh_nonblocking $FH, 1;

   $CB{die} = sub { die shift };

   $fh_r_watcher = EV::io $FH, EV::READ , \&fh_read;
   $fh_w_watcher = EV::io $FH, EV::WRITE, \&fh_write;
}

sub stop {
   close $FH;
}

package DC::DB;

sub nuke_db {
   File::Path::mkpath [$DB_HOME];
   eval { File::Path::rmtree $DB_HOME };
}

sub open_db {
   unless (eval { try_open_db }) {
      warn "$@";#d#
      eval { nuke_db };
      try_open_db;
   }

   # fetch the full face table first
   unless ($facemap) {
      do_table facemap => sub {
         $facemap = $_[0];
         delete $facemap->{id};
         my %maptile = reverse %$facemap;#d#
         if ((scalar keys %$facemap) != (scalar keys %maptile)) {#d#
            $facemap = { };#d#
            DC::error "FATAL: facemap is not a 1:1 mapping, please report this and delete your $DB_HOME directory!\n";#d#
         }#d#
      };
   }

   $WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
   $SYNC = EV::timer_ns 0, 60, sub {
      $_[0]->stop;
      db_env_txn_checkpoint $DB_ENV, 0, 0, 0, sub { };
   };
}

END {
   undef $TILE_SEQ;
   %DB_TABLE = ();
   undef $DB_ENV;
}

1;

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

Revision:	1.36
Committed:	Thu Apr 17 03:46:39 2008 UTC (16 years, 1 month ago) by root
Branch:	MAIN
CVS Tags:	rel-0_9972, rel-0_9973, rel-0_9971
Changes since 1.35:	+9 -7 lines
Log Message:	upgrade to perl5.10/windows and newest gtk+, pango etc.
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.31	DC::DB - async. database and filesystem access for deliantra
4	root	1.1
5			=head1 SYNOPSIS
6
7	root	1.29	use DC::DB;
8	root	1.1
9			=head1 DESCRIPTION
10
11			=over 4
12
13			=cut
14
15	root	1.29	package DC::DB;
16	root	1.1
17			use strict;
18			use utf8;
19
20	root	1.35	use File::Path ();
21	root	1.1	use Carp ();
22	root	1.5	use Storable ();
23	root	1.9	use Config;
24	root	1.24	use BDB;
25	root	1.1
26	root	1.29	use DC;
27	root	1.3
28	root	1.31	our $ODBDIR = "cfplus-" . BDB::VERSION . "-$Config{archname}";
29			our $DBDIR = "client-" . BDB::VERSION . "-$Config{archname}";
30	root	1.27	our $DB_HOME = "$Deliantra::VARDIR/$DBDIR";
31
32	root	1.35	unless (-d $DB_HOME) {
33			if (-d "$Deliantra::VARDIR/$ODBDIR") {
34			rename "$Deliantra::VARDIR/$ODBDIR", $DB_HOME;
35			print STDERR "INFO: moved old database from $Deliantra::VARDIR/$ODBDIR to $DB_HOME\n";
36			} elsif (-d "$Deliantra::OLDDIR/$ODBDIR") {
37			rename "$Deliantra::OLDDIR/$DBDIR", $DB_HOME;
38			print STDERR "INFO: moved old database from $Deliantra::OLDDIR/$ODBDIR to $DB_HOME\n";
39			} else {
40			File::Path::mkpath [$DB_HOME]
41			or die "unable to create database directory $DB_HOME: $!";
42			}
43	root	1.27	}
44	root	1.9
45	root	1.30	BDB::max_poll_time 0.03;
46	root	1.32	BDB::max_parallel 1;
47	root	1.30
48	root	1.24	our $DB_ENV;
49			our $DB_STATE;
50			our %DB_TABLE;
51	root	1.35	our $TILE_SEQ;
52	root	1.24
53	root	1.33	sub try_open_db {
54	root	1.35	File::Path::mkpath [$DB_HOME];
55	root	1.24
56	root	1.36	my $env = db_env_create;
57	root	1.24
58	root	1.36	$env->set_errfile (\*STDERR);
59			$env->set_msgfile (\*STDERR);
60			$env->set_verbose (-1, 1);
61	root	1.24
62	root	1.36	$env->set_flags (BDB::AUTO_COMMIT \| BDB::LOG_AUTOREMOVE \| BDB::TXN_WRITE_NOSYNC);
63			$env->set_cachesize (0, 2048 * 1024, 0);
64	root	1.24
65	root	1.36	db_env_open $env, $DB_HOME,
66	root	1.24	BDB::CREATE \| BDB::REGISTER \| BDB::RECOVER \| BDB::INIT_MPOOL \| BDB::INIT_LOCK \| BDB::INIT_TXN,
67			0666;
68
69			$! and die "cannot open database environment $DB_HOME: " . BDB::strerror;
70
71	root	1.36	$DB_ENV = $env;
72
73	root	1.24	1
74			}
75
76			sub table($) {
77			$DB_TABLE{$_[0]} \|\|= do {
78			my ($table) = @_;
79
80			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
81
82			my $db = db_create $DB_ENV;
83			$db->set_flags (BDB::CHKSUM);
84
85			db_open $db, undef, $table, undef, BDB::BTREE,
86			BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0666;
87
88			$! and "unable to open/create database table $_[0]: ". BDB::strerror;
89
90			$db
91			}
92	root	1.9	}
93
94	root	1.24	#############################################################################
95
96	root	1.33	our $WATCHER;
97			our $SYNC;
98	root	1.34	our $facemap;
99	root	1.24
100	root	1.9	sub exists($$$) {
101	root	1.24	my ($db, $key, $cb) = @_;
102
103			my $data;
104			db_get table $db, undef, $key, $data, 0, sub {
105			$cb->($! ? () : length $data);
106			};
107	root	1.9	}
108
109	root	1.1	sub get($$$) {
110	root	1.24	my ($db, $key, $cb) = @_;
111
112			my $data;
113			db_get table $db, undef, $key, $data, 0, sub {
114			$cb->($! ? () : $data);
115			};
116	root	1.1	}
117
118			sub put($$$$) {
119	root	1.24	my ($db, $key, $data, $cb) = @_;
120
121			db_put table $db, undef, $key, $data, 0, sub {
122			$cb->($!);
123			$SYNC->again unless $SYNC->is_active;
124			};
125	root	1.1	}
126
127	root	1.24	sub do_table {
128			my ($db, $cb) = @_;
129
130			$db = table $db;
131
132			my $cursor = $db->cursor;
133			my %kv;
134
135			for (;;) {
136			db_c_get $cursor, my $k, my $v, BDB::NEXT;
137			last if $!;
138			$kv{$k} = $v;
139			}
140
141			$cb->(\%kv);
142	root	1.9	}
143
144	root	1.24	sub do_get_tile_id {
145			my ($name, $cb) = @_;
146
147			my $table = table "facemap";
148			my $id;
149
150	root	1.35	db_get $table, undef, $name => $id, 0;
151	root	1.34	$! or return $cb->($id);
152	root	1.24
153	root	1.35	unless ($TILE_SEQ) {
154			$TILE_SEQ = $table->sequence;
155			$TILE_SEQ->initial_value (64);
156			$TILE_SEQ->set_cachesize (0);
157			db_sequence_open $TILE_SEQ, undef, "id", BDB::CREATE;
158			}
159	root	1.24
160	root	1.35	db_sequence_get $TILE_SEQ, undef, 1, my $id;
161	root	1.24
162	root	1.35	die "unable to allocate tile id: $!"
163			if $!;
164
165			db_put $table, undef, $name => $id, 0;
166			$cb->($id);
167	root	1.24
168	root	1.15	}
169
170	root	1.1	sub get_tile_id_sync($) {
171	root	1.20	my ($name) = @_;
172	root	1.1
173	root	1.34	$facemap->{$name} \|\|= do {
174	root	1.1	my $id;
175	root	1.24	do_get_tile_id $name, sub {
176			$id = $_[0];
177			};
178			BDB::flush;
179	root	1.1	$id
180			}
181			}
182
183	root	1.24	#############################################################################
184
185			sub path_of_res($) {
186			utf8::downgrade $_[0]; # bug in unpack "H*"
187			"$DB_HOME/res-data-" . unpack "H*", $_[0]
188			}
189
190			sub sync {
191			# for debugging
192	root	1.29	#DC::DB::Server::req (sync => sub { });
193			DC::DB::Server::sync ();
194	root	1.24	}
195	root	1.1
196	root	1.24	sub unlink($$) {
197	root	1.29	DC::DB::Server::req (unlink => @_);
198	root	1.24	}
199	root	1.1
200	root	1.24	sub read_file($$) {
201	root	1.29	DC::DB::Server::req (read_file => @_);
202	root	1.24	}
203	root	1.1
204	root	1.24	sub write_file($$$) {
205	root	1.29	DC::DB::Server::req (write_file => @_);
206	root	1.24	}
207	root	1.1
208	root	1.24	sub prefetch_file($$$) {
209	root	1.29	DC::DB::Server::req (prefetch_file => @_);
210	root	1.24	}
211	root	1.1
212	root	1.24	sub logprint($$$) {
213	root	1.29	DC::DB::Server::req (logprint => @_);
214	root	1.1	}
215
216	root	1.30	#############################################################################
217
218	root	1.29	package DC::DB::Server;
219	root	1.1
220	root	1.24	use strict;
221	root	1.1
222	root	1.24	use EV ();
223			use Fcntl;
224	root	1.1
225			our %CB;
226			our $FH;
227			our $ID = "aaa0";
228			our ($fh_r_watcher, $fh_w_watcher);
229			our $sync_timer;
230			our $write_buf;
231			our $read_buf;
232
233			sub fh_write {
234			my $len = syswrite $FH, $write_buf;
235
236			substr $write_buf, 0, $len, "";
237
238	root	1.14	$fh_w_watcher->stop
239	root	1.1	unless length $write_buf;
240			}
241
242			sub fh_read {
243			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
244
245			die "FATAL: database process died\n"
246			if $status == 0 && defined $status;
247
248			while () {
249			return if 4 > length $read_buf;
250			my $len = unpack "N", $read_buf;
251
252			return if $len + 4 > length $read_buf;
253
254			substr $read_buf, 0, 4, "";
255			my $res = Storable::thaw substr $read_buf, 0, $len, "";
256
257			my ($id, @args) = @$res;
258			(delete $CB{$id})->(@args);
259			}
260			}
261
262			sub sync {
263			# biggest mess evarr
264			my $fds; (vec $fds, fileno $FH, 1) = 1;
265
266			while (1 < scalar keys %CB) {
267			my $r = $fds;
268			my $w = length $write_buf ? $fds : undef;
269			select $r, $w, undef, undef;
270
271			fh_write if vec $w, fileno $FH, 1;
272			fh_read if vec $r, fileno $FH, 1;
273			}
274			}
275
276			sub req {
277			my ($type, @args) = @_;
278			my $cb = pop @args;
279
280			my $id = ++$ID;
281			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
282			$CB{$id} = $cb;
283
284	root	1.14	$fh_w_watcher->start;
285	root	1.1	}
286
287	root	1.9	sub do_unlink {
288			unlink $_[0];
289			}
290
291	root	1.16	sub do_read_file {
292			my ($path) = @_;
293
294			utf8::downgrade $path;
295			open my $fh, "<:raw", $path
296			or return;
297			sysread $fh, my $buf, -s $fh;
298
299			$buf
300			}
301
302	root	1.9	sub do_write_file {
303	root	1.16	my ($path, $data) = @_;
304	root	1.9
305	root	1.16	utf8::downgrade $path;
306	root	1.9	utf8::downgrade $data;
307	root	1.16	open my $fh, ">:raw", $path
308	root	1.9	or return;
309	root	1.16	syswrite $fh, $data;
310	root	1.9	close $fh;
311
312			1
313			}
314
315	root	1.11	sub do_prefetch_file {
316	root	1.16	my ($path, $size) = @_;
317	root	1.11
318	root	1.16	utf8::downgrade $path;
319			open my $fh, "<:raw", $path
320	root	1.11	or return;
321			sysread $fh, my $buf, $size;
322
323			1
324			}
325
326	root	1.15	our %LOG_FH;
327
328			sub do_logprint {
329			my ($path, $line) = @_;
330
331			$LOG_FH{$path} \|\|= do {
332			open my $fh, ">>:utf8", $path
333			or warn "Couldn't open logfile $path: $!";
334
335			$fh->autoflush (1);
336
337			$fh
338			};
339
340			my ($sec, $min, $hour, $mday, $mon, $year) = localtime time;
341
342			my $ts = sprintf "%04d-%02d-%02d %02d:%02d:%02d",
343			$year + 1900, $mon + 1, $mday, $hour, $min, $sec;
344
345			print { $LOG_FH{$path} } "$ts $line\n"
346			}
347
348	root	1.1	sub run {
349	root	1.29	($FH, my $fh) = DC::socketpipe;
350	root	1.1
351			my $oldfh = select $FH; $\| = 1; select $oldfh;
352			my $oldfh = select $fh; $\| = 1; select $oldfh;
353
354			my $pid = fork;
355
356			if (defined $pid && !$pid) {
357	root	1.30	local $SIG{QUIT} = "IGNORE";
358	root	1.1	local $SIG{__DIE__};
359	root	1.15	local $SIG{__WARN__};
360	root	1.1	eval {
361			close $FH;
362
363			while () {
364			4 == read $fh, my $len, 4
365			or last;
366			$len = unpack "N", $len;
367			$len == read $fh, my $req, $len
368			or die "unexpected eof while reading request";
369
370			$req = Storable::thaw $req;
371
372			my ($id, $type, @args) = @$req;
373	root	1.29	my $cb = DC::DB::Server->can ("do_$type")
374	root	1.1	or die "$type: unknown database request type\n";
375			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
376			(syswrite $fh, $res) == length $res
377	root	1.21	or die "DB::write: $!";
378	root	1.1	}
379			};
380
381			my $error = $@;
382
383			eval {
384			Storable::store_fd [die => $error], $fh;
385			};
386
387	root	1.25	warn $error
388			if $error;
389	root	1.24
390	root	1.29	DC::_exit 0;
391	root	1.1	}
392
393			close $fh;
394	root	1.29	DC::fh_nonblocking $FH, 1;
395	root	1.1
396	root	1.2	$CB{die} = sub { die shift };
397	root	1.1
398	root	1.21	$fh_r_watcher = EV::io $FH, EV::READ , \&fh_read;
399			$fh_w_watcher = EV::io $FH, EV::WRITE, \&fh_write;
400	root	1.1	}
401
402	root	1.6	sub stop {
403			close $FH;
404			}
405
406	root	1.33	package DC::DB;
407
408	root	1.35	sub nuke_db {
409			File::Path::mkpath [$DB_HOME];
410			eval { File::Path::rmtree $DB_HOME };
411			}
412
413	root	1.33	sub open_db {
414			unless (eval { try_open_db }) {
415			warn "$@";#d#
416	root	1.35	eval { nuke_db };
417	root	1.33	try_open_db;
418			}
419
420			# fetch the full face table first
421	root	1.34	unless ($facemap) {
422	root	1.33	do_table facemap => sub {
423	root	1.34	$facemap = $_[0];
424			delete $facemap->{id};
425			my %maptile = reverse %$facemap;#d#
426			if ((scalar keys %$facemap) != (scalar keys %maptile)) {#d#
427			$facemap = { };#d#
428	root	1.33	DC::error "FATAL: facemap is not a 1:1 mapping, please report this and delete your $DB_HOME directory!\n";#d#
429			}#d#
430			};
431			}
432
433			$WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
434			$SYNC = EV::timer_ns 0, 60, sub {
435			$_[0]->stop;
436			db_env_txn_checkpoint $DB_ENV, 0, 0, 0, sub { };
437			};
438			}
439
440			END {
441	root	1.35	undef $TILE_SEQ;
442	root	1.33	%DB_TABLE = ();
443			undef $DB_ENV;
444			}
445
446	root	1.1	1;
447
448			=back
449
450			=head1 AUTHOR
451
452			Marc Lehmann <schmorp@schmorp.de>
453			http://home.schmorp.de/
454
455			=cut
456