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 common::sense;

use File::Path ();
use Carp ();
use Storable ();
use AnyEvent::Util ();
use Config;
use BDB;
use Fcntl ();

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_ENV_FH;
our $DB_STATE;
our %DB_TABLE;
our $TILE_SEQ;

sub all_databases {
   opendir my $fh, $DB_HOME
      or return;

   grep !/^(?:\.|log\.|_)/, readdir $fh
}

sub try_verify_env($) {
   my ($env) = @_;

   open my $lock, "+>$DB_HOME/__lock"
      or die "__lock: $!";

   flock $lock, &Fcntl::LOCK_EX
      or die "flock: $!";

   # we look at the __db.register env file that has been created by now
   # and check for the number of registered processes - if there is
   # only one, we verify all databases, otherwise we skip this
   # we MUST NOT close the filehandle as longa swe keep the env open, as
   # this destroys the record locks on it.
   open $DB_ENV_FH, "<$DB_HOME/__db.register"
      or die "__db.register: $!";

   # __db.register contains one record per process, with X signifying
   # empty records (of course, this is completely private to bdb...)
   my $count = grep /^[^X]/, <$DB_ENV_FH>;

   if ($count == 1) {
      # if any databases are corrupted, we simply delete all of them

      for (all_databases) {
         my $dbh = db_create $env
            or last;

         # a failed verify will panic the environment, which is fine with us
         db_verify $dbh, "$DB_HOME/$_";

         return if $!; # nuke database and recreate if verification failure
      }

   }

   # close probably cleans those up, but we also want to run on windows,
   # so better be safe.
   flock $lock, &Fcntl::LOCK_UN
      or die "funlock: $!";

   1
}

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

   undef $DB_ENV;
   undef $DB_ENV_FH;

   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;

   # now we go through the registered processes, if there is only one, we verify all files
   # to make sure windows didn't corrupt them (as windows does....)
   try_verify_env $env
      or die "database environment failed verification";

   $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 common::sense;

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 {
   undef $DB_ENV;
   undef $DB_ENV_FH;

   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:	1.46
Committed:	Fri Jul 29 08:35:35 2011 UTC (12 years, 11 months ago) by root
Branch:	MAIN
Changes since 1.45:	+1 -1 lines
Log Message:	avoid triggering undefined behaviour
#	Content
1	=head1 NAME
2
3	DC::DB - async. database and filesystem access for deliantra
4
5	=head1 SYNOPSIS
6
7	use DC::DB;
8
9	=head1 DESCRIPTION
10
11	=over 4
12
13	=cut
14
15	package DC::DB;
16
17	use common::sense;
18
19	use File::Path ();
20	use Carp ();
21	use Storable ();
22	use AnyEvent::Util ();
23	use Config;
24	use BDB;
25	use Fcntl ();
26
27	use DC;
28
29	our $ODBDIR = "cfplus-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
30	our $DBDIR = "client-" . BDB::VERSION_MAJOR . "." . BDB::VERSION_MINOR . "-$Config{archname}";
31	our $DB_HOME = "$Deliantra::VARDIR/$DBDIR";
32
33	sub FIRST_TILE_ID () { 64 }
34
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	}
47
48	BDB::max_poll_time 0.03;
49	BDB::max_parallel 1;
50
51	our $DB_ENV;
52	our $DB_ENV_FH;
53	our $DB_STATE;
54	our %DB_TABLE;
55	our $TILE_SEQ;
56
57	sub all_databases {
58	opendir my $fh, $DB_HOME
59	or return;
60
61	grep !/^(?:\.\|log\.\|_)/, readdir $fh
62	}
63
64	sub try_verify_env($) {
65	my ($env) = @_;
66
67	open my $lock, "+>$DB_HOME/__lock"
68	or die "__lock: $!";
69
70	flock $lock, &Fcntl::LOCK_EX
71	or die "flock: $!";
72
73	# we look at the __db.register env file that has been created by now
74	# and check for the number of registered processes - if there is
75	# only one, we verify all databases, otherwise we skip this
76	# we MUST NOT close the filehandle as longa swe keep the env open, as
77	# this destroys the record locks on it.
78	open $DB_ENV_FH, "<$DB_HOME/__db.register"
79	or die "__db.register: $!";
80
81	# __db.register contains one record per process, with X signifying
82	# empty records (of course, this is completely private to bdb...)
83	my $count = grep /^[^X]/, <$DB_ENV_FH>;
84
85	if ($count == 1) {
86	# if any databases are corrupted, we simply delete all of them
87
88	for (all_databases) {
89	my $dbh = db_create $env
90	or last;
91
92	# a failed verify will panic the environment, which is fine with us
93	db_verify $dbh, "$DB_HOME/$_";
94
95	return if $!; # nuke database and recreate if verification failure
96	}
97
98	}
99
100	# close probably cleans those up, but we also want to run on windows,
101	# so better be safe.
102	flock $lock, &Fcntl::LOCK_UN
103	or die "funlock: $!";
104
105	1
106	}
107
108	sub try_open_db {
109	File::Path::mkpath [$DB_HOME];
110
111	undef $DB_ENV;
112	undef $DB_ENV_FH;
113
114	my $env = db_env_create;
115
116	$env->set_errfile (\*STDERR);
117	$env->set_msgfile (\*STDERR);
118	$env->set_verbose (-1, 1);
119
120	$env->set_flags (BDB::AUTO_COMMIT \| BDB::REGION_INIT);
121	$env->set_flags (&BDB::LOG_AUTOREMOVE ) if BDB::VERSION v0, v4.7;
122	$env->log_set_config (&BDB::LOG_AUTO_REMOVE) if BDB::VERSION v4.7;
123
124	$env->set_timeout (3, BDB::SET_TXN_TIMEOUT);
125	$env->set_timeout (3, BDB::SET_LOCK_TIMEOUT);
126
127	$env->set_cachesize (0, 2048 * 1024, 0);
128
129	db_env_open $env, $DB_HOME,
130	BDB::CREATE \| BDB::REGISTER \| BDB::RECOVER \| BDB::INIT_MPOOL \| BDB::INIT_LOCK \| BDB::INIT_TXN,
131	0666;
132
133	$! and die "cannot open database environment $DB_HOME: " . BDB::strerror;
134
135	# now we go through the registered processes, if there is only one, we verify all files
136	# to make sure windows didn't corrupt them (as windows does....)
137	try_verify_env $env
138	or die "database environment failed verification";
139
140	$DB_ENV = $env;
141
142	1
143	}
144
145	sub table($) {
146	$DB_TABLE{$_[0]} \|\|= do {
147	my ($table) = @_;
148
149	$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
150
151	$DB_ENV#d#
152	or return ::clienterror ("trying to create table $_[0] with empty db_env $DB_ENV" => 1);#d#
153
154	my $db = db_create $DB_ENV;
155	$db->set_flags (BDB::CHKSUM);
156
157	db_open $db, undef, $table, undef, BDB::BTREE,
158	BDB::AUTO_COMMIT \| BDB::CREATE \| BDB::READ_UNCOMMITTED, 0666;
159
160	$! and "unable to open/create database table $_[0]: ". BDB::strerror;
161
162	$db
163	}
164	}
165
166	#############################################################################
167
168	our $WATCHER;
169	our $SYNC;
170	our $facemap;
171
172	sub exists($$$) {
173	my ($db, $key, $cb) = @_;
174
175	my $data;
176	db_get table $db, undef, $key, $data, 0, sub {
177	$cb->($! ? () : length $data);
178	};
179	}
180
181	sub get($$$) {
182	my ($db, $key, $cb) = @_;
183
184	my $data;
185	db_get table $db, undef, $key, $data, 0, sub {
186	$cb->($! ? () : $data);
187	};
188	}
189
190	sub put($$$$) {
191	my ($db, $key, $data, $cb) = @_;
192
193	db_put table $db, undef, $key, $data, 0, sub {
194	$cb->($!);
195	$SYNC->again unless $SYNC->is_active;
196	};
197	}
198
199	sub do_table {
200	my ($db, $cb) = @_;
201
202	$db = table $db;
203
204	my $cursor = $db->cursor;
205	my %kv;
206
207	for (;;) {
208	db_c_get $cursor, my $k, my $v, BDB::NEXT;
209	last if $!;
210	$kv{$k} = $v;
211	}
212
213	$cb->(\%kv);
214	}
215
216	sub do_get_tile_id {
217	my ($name, $cb) = @_;
218
219	my $table = table "facemap";
220	my $id;
221
222	db_get $table, undef, $name => $id, 0;
223	$! or return $cb->($id);
224
225	unless ($TILE_SEQ) {
226	$TILE_SEQ = $table->sequence;
227	$TILE_SEQ->initial_value (FIRST_TILE_ID);
228	$TILE_SEQ->set_cachesize (0);
229	db_sequence_open $TILE_SEQ, undef, "id", BDB::CREATE;
230	}
231
232	db_sequence_get $TILE_SEQ, undef, 1, my $id;
233
234	die "unable to allocate tile id: $!"
235	if $!;
236
237	db_put $table, undef, $name => $id, 0;
238	$cb->($id);
239
240	}
241
242	sub get_tile_id_sync($) {
243	my ($name) = @_;
244
245	$facemap->{$name} \|\|= do {
246	my $id;
247	do_get_tile_id $name, sub {
248	$id = $_[0];
249	};
250	BDB::flush;
251	$id
252	}
253	}
254
255	#############################################################################
256
257	sub path_of_res($) {
258	utf8::downgrade $_[0]; # bug in unpack "H*"
259	"$DB_HOME/res-data-" . unpack "H*", $_[0]
260	}
261
262	sub sync {
263	# for debugging
264	#DC::DB::Server::req (sync => sub { });
265	DC::DB::Server::sync ();
266	}
267
268	sub unlink($$) {
269	DC::DB::Server::req (unlink => @_);
270	}
271
272	sub read_file($$) {
273	DC::DB::Server::req (read_file => @_);
274	}
275
276	sub write_file($$$) {
277	DC::DB::Server::req (write_file => @_);
278	}
279
280	sub prefetch_file($$$) {
281	DC::DB::Server::req (prefetch_file => @_);
282	}
283
284	sub logprint($$$) {
285	DC::DB::Server::req (logprint => @_);
286	}
287
288	#############################################################################
289
290	package DC::DB::Server;
291
292	use common::sense;
293
294	use EV ();
295	use Fcntl;
296
297	our %CB;
298	our $FH;
299	our $ID = "aaa0";
300	our ($fh_r_watcher, $fh_w_watcher);
301	our $sync_timer;
302	our $write_buf;
303	our $read_buf;
304
305	sub fh_write {
306	my $len = syswrite $FH, $write_buf;
307
308	substr $write_buf, 0, $len, "";
309
310	$fh_w_watcher->stop
311	unless length $write_buf;
312	}
313
314	sub fh_read {
315	my $status = sysread $FH, $read_buf, 16384, length $read_buf;
316
317	die "FATAL: database process died\n"
318	if $status == 0 && defined $status;
319
320	while () {
321	return if 4 > length $read_buf;
322	my $len = unpack "N", $read_buf;
323
324	return if $len + 4 > length $read_buf;
325
326	substr $read_buf, 0, 4, "";
327	my $res = Storable::thaw substr $read_buf, 0, $len, "";
328
329	my ($id, @args) = @$res;
330	(delete $CB{$id})->(@args);
331	}
332	}
333
334	sub sync {
335	# biggest mess evarr
336	my $fds; (vec $fds, fileno $FH, 1) = 1;
337
338	while (1 < scalar keys %CB) {
339	my $r = $fds;
340	my $w = length $write_buf ? $fds : undef;
341	select $r, $w, undef, undef;
342
343	fh_write if vec $w, fileno $FH, 1;
344	fh_read if vec $r, fileno $FH, 1;
345	}
346	}
347
348	sub req {
349	my ($type, @args) = @_;
350	my $cb = pop @args;
351
352	my $id = ++$ID;
353	$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
354	$CB{$id} = $cb;
355
356	$fh_w_watcher->start;
357	}
358
359	sub do_unlink {
360	unlink $_[0];
361	}
362
363	sub do_read_file {
364	my ($path) = @_;
365
366	utf8::downgrade $path;
367	open my $fh, "<:raw", $path
368	or return;
369	sysread $fh, my $buf, -s $fh;
370
371	$buf
372	}
373
374	sub do_write_file {
375	my ($path, $data) = @_;
376
377	utf8::downgrade $path;
378	utf8::downgrade $data;
379	open my $fh, ">:raw", $path
380	or return;
381	syswrite $fh, $data;
382	close $fh;
383
384	1
385	}
386
387	sub do_prefetch_file {
388	my ($path, $size) = @_;
389
390	utf8::downgrade $path;
391	open my $fh, "<:raw", $path
392	or return;
393	sysread $fh, my $buf, $size;
394
395	1
396	}
397
398	our %LOG_FH;
399
400	sub do_logprint {
401	my ($path, $line) = @_;
402
403	$LOG_FH{$path} \|\|= do {
404	open my $fh, ">>:utf8", $path
405	or warn "Couldn't open logfile $path: $!";
406
407	$fh->autoflush (1);
408
409	$fh
410	};
411
412	my ($sec, $min, $hour, $mday, $mon, $year) = localtime time;
413
414	my $ts = sprintf "%04d-%02d-%02d %02d:%02d:%02d",
415	$year + 1900, $mon + 1, $mday, $hour, $min, $sec;
416
417	print { $LOG_FH{$path} } "$ts $line\n"
418	}
419
420	sub run {
421	($FH, my $fh) = AnyEvent::Util::portable_socketpair
422	or die "unable to create database socketpair: $!";
423
424	my $oldfh = select $FH; $\| = 1; select $oldfh;
425	my $oldfh = select $fh; $\| = 1; select $oldfh;
426
427	my $pid = fork;
428
429	if (defined $pid && !$pid) {
430	local $SIG{QUIT} = "IGNORE";
431	local $SIG{__DIE__};
432	local $SIG{__WARN__};
433	eval {
434	close $FH;
435
436	while () {
437	4 == read $fh, my $len, 4
438	or last;
439	$len = unpack "N", $len;
440	$len == read $fh, my $req, $len
441	or die "unexpected eof while reading request";
442
443	$req = Storable::thaw $req;
444
445	my ($id, $type, @args) = @$req;
446	my $cb = DC::DB::Server->can ("do_$type")
447	or die "$type: unknown database request type\n";
448	my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
449	(syswrite $fh, $res) == length $res
450	or die "DB::write: $!";
451	}
452	};
453
454	my $error = $@;
455
456	eval {
457	Storable::store_fd [die => $error], $fh;
458	};
459
460	warn $error
461	if $error;
462
463	DC::_exit 0;
464	}
465
466	close $fh;
467	DC::fh_nonblocking $FH, 1;
468
469	$CB{die} = sub { die shift };
470
471	$fh_r_watcher = EV::io $FH, EV::READ , \&fh_read;
472	$fh_w_watcher = EV::io $FH, EV::WRITE, \&fh_write;
473	}
474
475	sub stop {
476	close $FH;
477	}
478
479	package DC::DB;
480
481	sub nuke_db {
482	undef $DB_ENV;
483	undef $DB_ENV_FH;
484
485	File::Path::mkpath [$DB_HOME];
486	eval { File::Path::rmtree $DB_HOME };
487	}
488
489	sub open_db {
490	unless (eval { try_open_db }) {
491	warn "$@";#d#
492	eval { nuke_db };
493	try_open_db;
494	}
495
496	# fetch the full face table first
497	unless ($facemap) {
498	do_table facemap => sub {
499	$facemap = $_[0];
500	delete $facemap->{id};
501	my %maptile = reverse %$facemap;#d#
502	if ((scalar keys %$facemap) != (scalar keys %maptile)) {#d#
503	$facemap = { };#d#
504	DC::error "FATAL: facemap is not a 1:1 mapping, please report this and delete your $DB_HOME directory!\n";#d#
505	}#d#
506	};
507	}
508
509	$WATCHER = EV::io BDB::poll_fileno, EV::READ, \&BDB::poll_cb;
510	$SYNC = EV::timer_ns 0, 60, sub {
511	$_[0]->stop;
512	db_env_txn_checkpoint $DB_ENV, 0, 0, 0, sub { };
513	};
514	}
515
516	END {
517	db_env_txn_checkpoint $DB_ENV, 0, 0, 0
518	if $DB_ENV;
519
520	undef $TILE_SEQ;
521	%DB_TABLE = ();
522	undef $DB_ENV;
523	}
524
525	1;
526
527	=back
528
529	=head1 AUTHOR
530
531	Marc Lehmann <schmorp@schmorp.de>
532	http://home.schmorp.de/
533
534	=cut
535