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

sub FIRST_TILE_ID () { 64 }

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::REGION_INIT);
   $env->set_flags      (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
   $env->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;

   $env->set_timeout (3, BDB::SET_TXN_TIMEOUT);
   $env->set_timeout (3, BDB::SET_LOCK_TIMEOUT);

   $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 (FIRST_TILE_ID);
      $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 {
   db_env_txn_checkpoint $DB_ENV, 0, 0, 0
      if $DB_ENV;

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

1;

=back

=head1 AUTHOR

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

=cut

Revision:	1.40
Committed:	Wed Nov 26 23:08:34 2008 UTC (15 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-2_0
Changes since 1.39:	+3 -1 lines
Log Message:	try and fail to unload on textures
#	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	1.38	our $ODBDIR = "cfplus-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
29			our $DBDIR = "client-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
30	root	1.27	our $DB_HOME = "$Deliantra::VARDIR/$DBDIR";
31
32	root	1.40	sub FIRST_TILE_ID () { 64 }
33
34	root	1.35	unless (-d $DB_HOME) {
35			if (-d "$Deliantra::VARDIR/$ODBDIR") {
36			rename "$Deliantra::VARDIR/$ODBDIR", $DB_HOME;
37			print STDERR "INFO: moved old database from $Deliantra::VARDIR/$ODBDIR to $DB_HOME\n";
38			} elsif (-d "$Deliantra::OLDDIR/$ODBDIR") {
39			rename "$Deliantra::OLDDIR/$DBDIR", $DB_HOME;
40			print STDERR "INFO: moved old database from $Deliantra::OLDDIR/$ODBDIR to $DB_HOME\n";
41			} else {
42			File::Path::mkpath [$DB_HOME]
43			or die "unable to create database directory $DB_HOME: $!";
44			}
45	root	1.27	}
46	root	1.9
47	root	1.30	BDB::max_poll_time 0.03;
48	root	1.32	BDB::max_parallel 1;
49	root	1.30
50	root	1.24	our $DB_ENV;
51			our $DB_STATE;
52			our %DB_TABLE;
53	root	1.35	our $TILE_SEQ;
54	root	1.24
55	root	1.33	sub try_open_db {
56	root	1.35	File::Path::mkpath [$DB_HOME];
57	root	1.24
58	root	1.36	my $env = db_env_create;
59	root	1.24
60	root	1.36	$env->set_errfile (\*STDERR);
61			$env->set_msgfile (\*STDERR);
62			$env->set_verbose (-1, 1);
63	root	1.24
64	root	1.39	$env->set_flags (BDB::AUTO_COMMIT \| BDB::REGION_INIT);
65			$env->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
66			$env->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
67
68			$env->set_timeout (3, BDB::SET_TXN_TIMEOUT);
69			$env->set_timeout (3, BDB::SET_LOCK_TIMEOUT);
70
71	root	1.36	$env->set_cachesize (0, 2048 * 1024, 0);
72	root	1.24
73	root	1.36	db_env_open $env, $DB_HOME,
74	root	1.24	BDB::CREATE \| BDB::REGISTER \| BDB::RECOVER \| BDB::INIT_MPOOL \| BDB::INIT_LOCK \| BDB::INIT_TXN,
75			0666;
76
77			$! and die "cannot open database environment $DB_HOME: " . BDB::strerror;
78
79	root	1.36	$DB_ENV = $env;
80
81	root	1.24	1
82			}
83
84			sub table($) {
85			$DB_TABLE{$_[0]} \|\|= do {
86			my ($table) = @_;
87
88			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
89
90			my $db = db_create $DB_ENV;
91			$db->set_flags (BDB::CHKSUM);
92
93			db_open $db, undef, $table, undef, BDB::BTREE,
94			BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0666;
95
96			$! and "unable to open/create database table $_[0]: ". BDB::strerror;
97
98			$db
99			}
100	root	1.9	}
101
102	root	1.24	#############################################################################
103
104	root	1.33	our $WATCHER;
105			our $SYNC;
106	root	1.34	our $facemap;
107	root	1.24
108	root	1.9	sub exists($$$) {
109	root	1.24	my ($db, $key, $cb) = @_;
110
111			my $data;
112			db_get table $db, undef, $key, $data, 0, sub {
113			$cb->($! ? () : length $data);
114			};
115	root	1.9	}
116
117	root	1.1	sub get($$$) {
118	root	1.24	my ($db, $key, $cb) = @_;
119
120			my $data;
121			db_get table $db, undef, $key, $data, 0, sub {
122			$cb->($! ? () : $data);
123			};
124	root	1.1	}
125
126			sub put($$$$) {
127	root	1.24	my ($db, $key, $data, $cb) = @_;
128
129			db_put table $db, undef, $key, $data, 0, sub {
130			$cb->($!);
131			$SYNC->again unless $SYNC->is_active;
132			};
133	root	1.1	}
134
135	root	1.24	sub do_table {
136			my ($db, $cb) = @_;
137
138			$db = table $db;
139
140			my $cursor = $db->cursor;
141			my %kv;
142
143			for (;;) {
144			db_c_get $cursor, my $k, my $v, BDB::NEXT;
145			last if $!;
146			$kv{$k} = $v;
147			}
148
149			$cb->(\%kv);
150	root	1.9	}
151
152	root	1.24	sub do_get_tile_id {
153			my ($name, $cb) = @_;
154
155			my $table = table "facemap";
156			my $id;
157
158	root	1.35	db_get $table, undef, $name => $id, 0;
159	root	1.34	$! or return $cb->($id);
160	root	1.24
161	root	1.35	unless ($TILE_SEQ) {
162			$TILE_SEQ = $table->sequence;
163	root	1.40	$TILE_SEQ->initial_value (FIRST_TILE_ID);
164	root	1.35	$TILE_SEQ->set_cachesize (0);
165			db_sequence_open $TILE_SEQ, undef, "id", BDB::CREATE;
166			}
167	root	1.24
168	root	1.35	db_sequence_get $TILE_SEQ, undef, 1, my $id;
169	root	1.24
170	root	1.35	die "unable to allocate tile id: $!"
171			if $!;
172
173			db_put $table, undef, $name => $id, 0;
174			$cb->($id);
175	root	1.24
176	root	1.15	}
177
178	root	1.1	sub get_tile_id_sync($) {
179	root	1.20	my ($name) = @_;
180	root	1.1
181	root	1.34	$facemap->{$name} \|\|= do {
182	root	1.1	my $id;
183	root	1.24	do_get_tile_id $name, sub {
184			$id = $_[0];
185			};
186			BDB::flush;
187	root	1.1	$id
188			}
189			}
190
191	root	1.24	#############################################################################
192
193			sub path_of_res($) {
194			utf8::downgrade $_[0]; # bug in unpack "H*"
195			"$DB_HOME/res-data-" . unpack "H*", $_[0]
196			}
197
198			sub sync {
199			# for debugging
200	root	1.29	#DC::DB::Server::req (sync => sub { });
201			DC::DB::Server::sync ();
202	root	1.24	}
203	root	1.1
204	root	1.24	sub unlink($$) {
205	root	1.29	DC::DB::Server::req (unlink => @_);
206	root	1.24	}
207	root	1.1
208	root	1.24	sub read_file($$) {
209	root	1.29	DC::DB::Server::req (read_file => @_);
210	root	1.24	}
211	root	1.1
212	root	1.24	sub write_file($$$) {
213	root	1.29	DC::DB::Server::req (write_file => @_);
214	root	1.24	}
215	root	1.1
216	root	1.24	sub prefetch_file($$$) {
217	root	1.29	DC::DB::Server::req (prefetch_file => @_);
218	root	1.24	}
219	root	1.1
220	root	1.24	sub logprint($$$) {
221	root	1.29	DC::DB::Server::req (logprint => @_);
222	root	1.1	}
223
224	root	1.30	#############################################################################
225
226	root	1.29	package DC::DB::Server;
227	root	1.1
228	root	1.24	use strict;
229	root	1.1
230	root	1.24	use EV ();
231			use Fcntl;
232	root	1.1
233			our %CB;
234			our $FH;
235			our $ID = "aaa0";
236			our ($fh_r_watcher, $fh_w_watcher);
237			our $sync_timer;
238			our $write_buf;
239			our $read_buf;
240
241			sub fh_write {
242			my $len = syswrite $FH, $write_buf;
243
244			substr $write_buf, 0, $len, "";
245
246	root	1.14	$fh_w_watcher->stop
247	root	1.1	unless length $write_buf;
248			}
249
250			sub fh_read {
251			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
252
253			die "FATAL: database process died\n"
254			if $status == 0 && defined $status;
255
256			while () {
257			return if 4 > length $read_buf;
258			my $len = unpack "N", $read_buf;
259
260			return if $len + 4 > length $read_buf;
261
262			substr $read_buf, 0, 4, "";
263			my $res = Storable::thaw substr $read_buf, 0, $len, "";
264
265			my ($id, @args) = @$res;
266			(delete $CB{$id})->(@args);
267			}
268			}
269
270			sub sync {
271			# biggest mess evarr
272			my $fds; (vec $fds, fileno $FH, 1) = 1;
273
274			while (1 < scalar keys %CB) {
275			my $r = $fds;
276			my $w = length $write_buf ? $fds : undef;
277			select $r, $w, undef, undef;
278
279			fh_write if vec $w, fileno $FH, 1;
280			fh_read if vec $r, fileno $FH, 1;
281			}
282			}
283
284			sub req {
285			my ($type, @args) = @_;
286			my $cb = pop @args;
287
288			my $id = ++$ID;
289			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
290			$CB{$id} = $cb;
291
292	root	1.14	$fh_w_watcher->start;
293	root	1.1	}
294
295	root	1.9	sub do_unlink {
296			unlink $_[0];
297			}
298
299	root	1.16	sub do_read_file {
300			my ($path) = @_;
301
302			utf8::downgrade $path;
303			open my $fh, "<:raw", $path
304			or return;
305			sysread $fh, my $buf, -s $fh;
306
307			$buf
308			}
309
310	root	1.9	sub do_write_file {
311	root	1.16	my ($path, $data) = @_;
312	root	1.9
313	root	1.16	utf8::downgrade $path;
314	root	1.9	utf8::downgrade $data;
315	root	1.16	open my $fh, ">:raw", $path
316	root	1.9	or return;
317	root	1.16	syswrite $fh, $data;
318	root	1.9	close $fh;
319
320			1
321			}
322
323	root	1.11	sub do_prefetch_file {
324	root	1.16	my ($path, $size) = @_;
325	root	1.11
326	root	1.16	utf8::downgrade $path;
327			open my $fh, "<:raw", $path
328	root	1.11	or return;
329			sysread $fh, my $buf, $size;
330
331			1
332			}
333
334	root	1.15	our %LOG_FH;
335
336			sub do_logprint {
337			my ($path, $line) = @_;
338
339			$LOG_FH{$path} \|\|= do {
340			open my $fh, ">>:utf8", $path
341			or warn "Couldn't open logfile $path: $!";
342
343			$fh->autoflush (1);
344
345			$fh
346			};
347
348			my ($sec, $min, $hour, $mday, $mon, $year) = localtime time;
349
350			my $ts = sprintf "%04d-%02d-%02d %02d:%02d:%02d",
351			$year + 1900, $mon + 1, $mday, $hour, $min, $sec;
352
353			print { $LOG_FH{$path} } "$ts $line\n"
354			}
355
356	root	1.1	sub run {
357	root	1.29	($FH, my $fh) = DC::socketpipe;
358	root	1.1
359			my $oldfh = select $FH; $\| = 1; select $oldfh;
360			my $oldfh = select $fh; $\| = 1; select $oldfh;
361
362			my $pid = fork;
363
364			if (defined $pid && !$pid) {
365	root	1.30	local $SIG{QUIT} = "IGNORE";
366	root	1.1	local $SIG{__DIE__};
367	root	1.15	local $SIG{__WARN__};
368	root	1.1	eval {
369			close $FH;
370
371			while () {
372			4 == read $fh, my $len, 4
373			or last;
374			$len = unpack "N", $len;
375			$len == read $fh, my $req, $len
376			or die "unexpected eof while reading request";
377
378			$req = Storable::thaw $req;
379
380			my ($id, $type, @args) = @$req;
381	root	1.29	my $cb = DC::DB::Server->can ("do_$type")
382	root	1.1	or die "$type: unknown database request type\n";
383			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
384			(syswrite $fh, $res) == length $res
385	root	1.21	or die "DB::write: $!";
386	root	1.1	}
387			};
388
389			my $error = $@;
390
391			eval {
392			Storable::store_fd [die => $error], $fh;
393			};
394
395	root	1.25	warn $error
396			if $error;
397	root	1.24
398	root	1.29	DC::_exit 0;
399	root	1.1	}
400
401			close $fh;
402	root	1.29	DC::fh_nonblocking $FH, 1;
403	root	1.1
404	root	1.2	$CB{die} = sub { die shift };
405	root	1.1
406	root	1.21	$fh_r_watcher = EV::io $FH, EV::READ , \&fh_read;
407			$fh_w_watcher = EV::io $FH, EV::WRITE, \&fh_write;
408	root	1.1	}
409
410	root	1.6	sub stop {
411			close $FH;
412			}
413
414	root	1.33	package DC::DB;
415
416	root	1.35	sub nuke_db {
417			File::Path::mkpath [$DB_HOME];
418			eval { File::Path::rmtree $DB_HOME };
419			}
420
421	root	1.33	sub open_db {
422			unless (eval { try_open_db }) {
423			warn "$@";#d#
424	root	1.35	eval { nuke_db };
425	root	1.33	try_open_db;
426			}
427
428			# fetch the full face table first
429	root	1.34	unless ($facemap) {
430	root	1.33	do_table facemap => sub {
431	root	1.34	$facemap = $_[0];
432			delete $facemap->{id};
433			my %maptile = reverse %$facemap;#d#
434			if ((scalar keys %$facemap) != (scalar keys %maptile)) {#d#
435			$facemap = { };#d#
436	root	1.33	DC::error "FATAL: facemap is not a 1:1 mapping, please report this and delete your $DB_HOME directory!\n";#d#
437			}#d#
438			};
439			}
440
441			$WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
442			$SYNC = EV::timer_ns 0, 60, sub {
443			$_[0]->stop;
444			db_env_txn_checkpoint $DB_ENV, 0, 0, 0, sub { };
445			};
446			}
447
448			END {
449	root	1.37	db_env_txn_checkpoint $DB_ENV, 0, 0, 0
450			if $DB_ENV;
451
452	root	1.35	undef $TILE_SEQ;
453	root	1.33	%DB_TABLE = ();
454			undef $DB_ENV;
455			}
456
457	root	1.1	1;
458
459			=back
460
461			=head1 AUTHOR
462
463			Marc Lehmann <schmorp@schmorp.de>
464			http://home.schmorp.de/
465
466			=cut
467