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 AnyEvent::Util ();
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;

      $DB_ENV#d#
         or return ::clienterror ("trying to create table $_[0] with empty db_env $DB_ENV" => 1);#d#

      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) = AnyEvent::Util::portable_socketpair
     or die "unable to create database socketpair: $!";

   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:	1.42
Committed:	Sun Jan 4 10:22:19 2009 UTC (15 years, 5 months ago) by root
Branch:	MAIN
Changes since 1.41:	+3 -1 lines
Log Message:	* empty log message *
#	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	1.42	use AnyEvent::Util ();
24	root	1.9	use Config;
25	root	1.24	use BDB;
26	root	1.1
27	root	1.29	use DC;
28	root	1.3
29	root	1.38	our $ODBDIR = "cfplus-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
30			our $DBDIR = "client-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
31	root	1.27	our $DB_HOME = "$Deliantra::VARDIR/$DBDIR";
32
33	root	1.40	sub FIRST_TILE_ID () { 64 }
34
35	root	1.35	unless (-d $DB_HOME) {
36			if (-d "$Deliantra::VARDIR/$ODBDIR") {
37			rename "$Deliantra::VARDIR/$ODBDIR", $DB_HOME;
38			print STDERR "INFO: moved old database from $Deliantra::VARDIR/$ODBDIR to $DB_HOME\n";
39			} elsif (-d "$Deliantra::OLDDIR/$ODBDIR") {
40			rename "$Deliantra::OLDDIR/$DBDIR", $DB_HOME;
41			print STDERR "INFO: moved old database from $Deliantra::OLDDIR/$ODBDIR to $DB_HOME\n";
42			} else {
43			File::Path::mkpath [$DB_HOME]
44			or die "unable to create database directory $DB_HOME: $!";
45			}
46	root	1.27	}
47	root	1.9
48	root	1.30	BDB::max_poll_time 0.03;
49	root	1.32	BDB::max_parallel 1;
50	root	1.30
51	root	1.24	our $DB_ENV;
52			our $DB_STATE;
53			our %DB_TABLE;
54	root	1.35	our $TILE_SEQ;
55	root	1.24
56	root	1.33	sub try_open_db {
57	root	1.35	File::Path::mkpath [$DB_HOME];
58	root	1.24
59	root	1.36	my $env = db_env_create;
60	root	1.24
61	root	1.36	$env->set_errfile (\*STDERR);
62			$env->set_msgfile (\*STDERR);
63			$env->set_verbose (-1, 1);
64	root	1.24
65	root	1.39	$env->set_flags (BDB::AUTO_COMMIT \| BDB::REGION_INIT);
66			$env->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
67			$env->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
68
69			$env->set_timeout (3, BDB::SET_TXN_TIMEOUT);
70			$env->set_timeout (3, BDB::SET_LOCK_TIMEOUT);
71
72	root	1.36	$env->set_cachesize (0, 2048 * 1024, 0);
73	root	1.24
74	root	1.36	db_env_open $env, $DB_HOME,
75	root	1.24	BDB::CREATE \| BDB::REGISTER \| BDB::RECOVER \| BDB::INIT_MPOOL \| BDB::INIT_LOCK \| BDB::INIT_TXN,
76			0666;
77
78			$! and die "cannot open database environment $DB_HOME: " . BDB::strerror;
79
80	root	1.36	$DB_ENV = $env;
81
82	root	1.24	1
83			}
84
85			sub table($) {
86			$DB_TABLE{$_[0]} \|\|= do {
87			my ($table) = @_;
88
89			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
90
91	root	1.41	$DB_ENV#d#
92			or return ::clienterror ("trying to create table $_[0] with empty db_env $DB_ENV" => 1);#d#
93
94	root	1.24	my $db = db_create $DB_ENV;
95			$db->set_flags (BDB::CHKSUM);
96
97			db_open $db, undef, $table, undef, BDB::BTREE,
98			BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0666;
99
100			$! and "unable to open/create database table $_[0]: ". BDB::strerror;
101
102			$db
103			}
104	root	1.9	}
105
106	root	1.24	#############################################################################
107
108	root	1.33	our $WATCHER;
109			our $SYNC;
110	root	1.34	our $facemap;
111	root	1.24
112	root	1.9	sub exists($$$) {
113	root	1.24	my ($db, $key, $cb) = @_;
114
115			my $data;
116			db_get table $db, undef, $key, $data, 0, sub {
117			$cb->($! ? () : length $data);
118			};
119	root	1.9	}
120
121	root	1.1	sub get($$$) {
122	root	1.24	my ($db, $key, $cb) = @_;
123
124			my $data;
125			db_get table $db, undef, $key, $data, 0, sub {
126			$cb->($! ? () : $data);
127			};
128	root	1.1	}
129
130			sub put($$$$) {
131	root	1.24	my ($db, $key, $data, $cb) = @_;
132
133			db_put table $db, undef, $key, $data, 0, sub {
134			$cb->($!);
135			$SYNC->again unless $SYNC->is_active;
136			};
137	root	1.1	}
138
139	root	1.24	sub do_table {
140			my ($db, $cb) = @_;
141
142			$db = table $db;
143
144			my $cursor = $db->cursor;
145			my %kv;
146
147			for (;;) {
148			db_c_get $cursor, my $k, my $v, BDB::NEXT;
149			last if $!;
150			$kv{$k} = $v;
151			}
152
153			$cb->(\%kv);
154	root	1.9	}
155
156	root	1.24	sub do_get_tile_id {
157			my ($name, $cb) = @_;
158
159			my $table = table "facemap";
160			my $id;
161
162	root	1.35	db_get $table, undef, $name => $id, 0;
163	root	1.34	$! or return $cb->($id);
164	root	1.24
165	root	1.35	unless ($TILE_SEQ) {
166			$TILE_SEQ = $table->sequence;
167	root	1.40	$TILE_SEQ->initial_value (FIRST_TILE_ID);
168	root	1.35	$TILE_SEQ->set_cachesize (0);
169			db_sequence_open $TILE_SEQ, undef, "id", BDB::CREATE;
170			}
171	root	1.24
172	root	1.35	db_sequence_get $TILE_SEQ, undef, 1, my $id;
173	root	1.24
174	root	1.35	die "unable to allocate tile id: $!"
175			if $!;
176
177			db_put $table, undef, $name => $id, 0;
178			$cb->($id);
179	root	1.24
180	root	1.15	}
181
182	root	1.1	sub get_tile_id_sync($) {
183	root	1.20	my ($name) = @_;
184	root	1.1
185	root	1.34	$facemap->{$name} \|\|= do {
186	root	1.1	my $id;
187	root	1.24	do_get_tile_id $name, sub {
188			$id = $_[0];
189			};
190			BDB::flush;
191	root	1.1	$id
192			}
193			}
194
195	root	1.24	#############################################################################
196
197			sub path_of_res($) {
198			utf8::downgrade $_[0]; # bug in unpack "H*"
199			"$DB_HOME/res-data-" . unpack "H*", $_[0]
200			}
201
202			sub sync {
203			# for debugging
204	root	1.29	#DC::DB::Server::req (sync => sub { });
205			DC::DB::Server::sync ();
206	root	1.24	}
207	root	1.1
208	root	1.24	sub unlink($$) {
209	root	1.29	DC::DB::Server::req (unlink => @_);
210	root	1.24	}
211	root	1.1
212	root	1.24	sub read_file($$) {
213	root	1.29	DC::DB::Server::req (read_file => @_);
214	root	1.24	}
215	root	1.1
216	root	1.24	sub write_file($$$) {
217	root	1.29	DC::DB::Server::req (write_file => @_);
218	root	1.24	}
219	root	1.1
220	root	1.24	sub prefetch_file($$$) {
221	root	1.29	DC::DB::Server::req (prefetch_file => @_);
222	root	1.24	}
223	root	1.1
224	root	1.24	sub logprint($$$) {
225	root	1.29	DC::DB::Server::req (logprint => @_);
226	root	1.1	}
227
228	root	1.30	#############################################################################
229
230	root	1.29	package DC::DB::Server;
231	root	1.1
232	root	1.24	use strict;
233	root	1.1
234	root	1.24	use EV ();
235			use Fcntl;
236	root	1.1
237			our %CB;
238			our $FH;
239			our $ID = "aaa0";
240			our ($fh_r_watcher, $fh_w_watcher);
241			our $sync_timer;
242			our $write_buf;
243			our $read_buf;
244
245			sub fh_write {
246			my $len = syswrite $FH, $write_buf;
247
248			substr $write_buf, 0, $len, "";
249
250	root	1.14	$fh_w_watcher->stop
251	root	1.1	unless length $write_buf;
252			}
253
254			sub fh_read {
255			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
256
257			die "FATAL: database process died\n"
258			if $status == 0 && defined $status;
259
260			while () {
261			return if 4 > length $read_buf;
262			my $len = unpack "N", $read_buf;
263
264			return if $len + 4 > length $read_buf;
265
266			substr $read_buf, 0, 4, "";
267			my $res = Storable::thaw substr $read_buf, 0, $len, "";
268
269			my ($id, @args) = @$res;
270			(delete $CB{$id})->(@args);
271			}
272			}
273
274			sub sync {
275			# biggest mess evarr
276			my $fds; (vec $fds, fileno $FH, 1) = 1;
277
278			while (1 < scalar keys %CB) {
279			my $r = $fds;
280			my $w = length $write_buf ? $fds : undef;
281			select $r, $w, undef, undef;
282
283			fh_write if vec $w, fileno $FH, 1;
284			fh_read if vec $r, fileno $FH, 1;
285			}
286			}
287
288			sub req {
289			my ($type, @args) = @_;
290			my $cb = pop @args;
291
292			my $id = ++$ID;
293			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
294			$CB{$id} = $cb;
295
296	root	1.14	$fh_w_watcher->start;
297	root	1.1	}
298
299	root	1.9	sub do_unlink {
300			unlink $_[0];
301			}
302
303	root	1.16	sub do_read_file {
304			my ($path) = @_;
305
306			utf8::downgrade $path;
307			open my $fh, "<:raw", $path
308			or return;
309			sysread $fh, my $buf, -s $fh;
310
311			$buf
312			}
313
314	root	1.9	sub do_write_file {
315	root	1.16	my ($path, $data) = @_;
316	root	1.9
317	root	1.16	utf8::downgrade $path;
318	root	1.9	utf8::downgrade $data;
319	root	1.16	open my $fh, ">:raw", $path
320	root	1.9	or return;
321	root	1.16	syswrite $fh, $data;
322	root	1.9	close $fh;
323
324			1
325			}
326
327	root	1.11	sub do_prefetch_file {
328	root	1.16	my ($path, $size) = @_;
329	root	1.11
330	root	1.16	utf8::downgrade $path;
331			open my $fh, "<:raw", $path
332	root	1.11	or return;
333			sysread $fh, my $buf, $size;
334
335			1
336			}
337
338	root	1.15	our %LOG_FH;
339
340			sub do_logprint {
341			my ($path, $line) = @_;
342
343			$LOG_FH{$path} \|\|= do {
344			open my $fh, ">>:utf8", $path
345			or warn "Couldn't open logfile $path: $!";
346
347			$fh->autoflush (1);
348
349			$fh
350			};
351
352			my ($sec, $min, $hour, $mday, $mon, $year) = localtime time;
353
354			my $ts = sprintf "%04d-%02d-%02d %02d:%02d:%02d",
355			$year + 1900, $mon + 1, $mday, $hour, $min, $sec;
356
357			print { $LOG_FH{$path} } "$ts $line\n"
358			}
359
360	root	1.1	sub run {
361	root	1.42	($FH, my $fh) = AnyEvent::Util::portable_socketpair
362			or die "unable to create database socketpair: $!";
363	root	1.1
364			my $oldfh = select $FH; $\| = 1; select $oldfh;
365			my $oldfh = select $fh; $\| = 1; select $oldfh;
366
367			my $pid = fork;
368
369			if (defined $pid && !$pid) {
370	root	1.30	local $SIG{QUIT} = "IGNORE";
371	root	1.1	local $SIG{__DIE__};
372	root	1.15	local $SIG{__WARN__};
373	root	1.1	eval {
374			close $FH;
375
376			while () {
377			4 == read $fh, my $len, 4
378			or last;
379			$len = unpack "N", $len;
380			$len == read $fh, my $req, $len
381			or die "unexpected eof while reading request";
382
383			$req = Storable::thaw $req;
384
385			my ($id, $type, @args) = @$req;
386	root	1.29	my $cb = DC::DB::Server->can ("do_$type")
387	root	1.1	or die "$type: unknown database request type\n";
388			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
389			(syswrite $fh, $res) == length $res
390	root	1.21	or die "DB::write: $!";
391	root	1.1	}
392			};
393
394			my $error = $@;
395
396			eval {
397			Storable::store_fd [die => $error], $fh;
398			};
399
400	root	1.25	warn $error
401			if $error;
402	root	1.24
403	root	1.29	DC::_exit 0;
404	root	1.1	}
405
406			close $fh;
407	root	1.29	DC::fh_nonblocking $FH, 1;
408	root	1.1
409	root	1.2	$CB{die} = sub { die shift };
410	root	1.1
411	root	1.21	$fh_r_watcher = EV::io $FH, EV::READ , \&fh_read;
412			$fh_w_watcher = EV::io $FH, EV::WRITE, \&fh_write;
413	root	1.1	}
414
415	root	1.6	sub stop {
416			close $FH;
417			}
418
419	root	1.33	package DC::DB;
420
421	root	1.35	sub nuke_db {
422			File::Path::mkpath [$DB_HOME];
423			eval { File::Path::rmtree $DB_HOME };
424			}
425
426	root	1.33	sub open_db {
427			unless (eval { try_open_db }) {
428			warn "$@";#d#
429	root	1.35	eval { nuke_db };
430	root	1.33	try_open_db;
431			}
432
433			# fetch the full face table first
434	root	1.34	unless ($facemap) {
435	root	1.33	do_table facemap => sub {
436	root	1.34	$facemap = $_[0];
437			delete $facemap->{id};
438			my %maptile = reverse %$facemap;#d#
439			if ((scalar keys %$facemap) != (scalar keys %maptile)) {#d#
440			$facemap = { };#d#
441	root	1.33	DC::error "FATAL: facemap is not a 1:1 mapping, please report this and delete your $DB_HOME directory!\n";#d#
442			}#d#
443			};
444			}
445
446			$WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
447			$SYNC = EV::timer_ns 0, 60, sub {
448			$_[0]->stop;
449			db_env_txn_checkpoint $DB_ENV, 0, 0, 0, sub { };
450			};
451			}
452
453			END {
454	root	1.37	db_env_txn_checkpoint $DB_ENV, 0, 0, 0
455			if $DB_ENV;
456
457	root	1.35	undef $TILE_SEQ;
458	root	1.33	%DB_TABLE = ();
459			undef $DB_ENV;
460			}
461
462	root	1.1	1;
463
464			=back
465
466			=head1 AUTHOR
467
468			Marc Lehmann <schmorp@schmorp.de>
469			http://home.schmorp.de/
470
471			=cut
472