Deliantra-Client/DC/DB.pm

=head1 NAME

CFPlus::DB - async. database and filesystem access for cfplus

=head1 SYNOPSIS

 use CFPlus::DB;

=head1 DESCRIPTION

=over 4

=cut

package CFPlus::DB;

use strict;
use utf8;

use Carp ();
use AnyEvent ();
use Storable ();
use Config;

use CFPlus;

our $DB_HOME = "$Crossfire::VARDIR/cfplus-$BerkeleyDB::db_version-$Config{archname}";

sub path_of($) {
   "$DB_HOME/data-$_[0]"
}

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

sub exists($$$) {
   CFPlus::DB::Server::req (exists => @_);
}

sub get($$$) {
   CFPlus::DB::Server::req (get => @_);
}

sub put($$$$) {
   CFPlus::DB::Server::req (put => @_);
}

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

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

our $tilemap;

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

   # fetch the full face table first
   unless ($tilemap) {
      CFPlus::DB::Server::req (table => facemap => sub { $tilemap = $_[0] });
      sync;
   }

   $tilemap->{$hash} ||= do {
      my $id;
      CFPlus::DB::Server::req (get_tile_id => $hash, sub { $id = $_[0] });
      sync;
      $id
   }
}

package CFPlus::DB::Server;

use strict;

use Fcntl;
use BerkeleyDB;

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

sub open_db {
   mkdir $DB_HOME, 0777;
   my $recover = $BerkeleyDB::db_version >= 4.4 
                 ? eval "DB_REGISTER | DB_RECOVER"
                 : 0;

   $DB_ENV = new BerkeleyDB::Env
                    -Home => $DB_HOME,
                    -Cachesize => 8_000_000,
                    -ErrFile => "$DB_HOME/errorlog.txt",
#                 -ErrPrefix => "DATABASE",
                    -Verbose => 1,
                    -Flags => DB_CREATE | DB_RECOVER | DB_INIT_MPOOL | DB_INIT_LOCK | DB_INIT_TXN | $recover,
                    -SetFlags => DB_AUTO_COMMIT | DB_LOG_AUTOREMOVE,
                       or die "unable to create/open database home $DB_HOME: $BerkeleyDB::Error";

   1
}

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

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

      new BerkeleyDB::Btree
         -Env      => $DB_ENV,
         -Filename => $table,
#      -Filename => "database",
#      -Subname  => $table,
         -Property => DB_CHKSUM,
         -Flags    => DB_CREATE | DB_UPGRADE,
            or die "unable to create/open database table $_[0]: $BerkeleyDB::Error"
   }
}

our $SYNC_INTERVAL = 60;

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, "";

   undef $fh_w_watcher
      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 = AnyEvent->io (fh => $FH, poll => 'w', cb => \&fh_write);
}

sub sync_tick {
   req "sync", sub { };
   $sync_timer = AnyEvent->timer (after => $SYNC_INTERVAL, cb => \&sync_tick);
}

sub do_sync {
   $DB_ENV->txn_checkpoint (0, 0, 0);
   ()
}

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

   utf8::downgrade $key;
   my $data;
   (table $db)->db_get ($key, $data) == 0
      ? length $data
      : ()
}

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

   utf8::downgrade $key;
   my $data;
   (table $db)->db_get ($key, $data) == 0
      ? $data
      : ()
}

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

   utf8::downgrade $key;
   utf8::downgrade $data;
   (table $db)->db_put ($key => $data)
}

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

   $db = table $db;

   my $cursor = $db->db_cursor;
   my %kv;
   my ($k, $v);
   $kv{$k} = $v while $cursor->c_get ($k, $v, BerkeleyDB::DB_NEXT) == 0;

   \%kv
}

sub do_get_tile_id {
   my ($hash) = @_;

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

   return $id
      if $table->db_get ($hash, $id) == 0;

   for (1..100) {
      my $txn = $DB_ENV->txn_begin;
      my $status = $table->db_get (id => $id);
      if ($status == 0 || $status == BerkeleyDB::DB_NOTFOUND) {
         $id = ($id || 64) + 1;
         if ($table->db_put (id => $id) == 0
             && $table->db_put ($hash => $id) == 0) {
            $txn->txn_commit;

            return $id;
         }
      }
      $txn->txn_abort;
   }

   die "maximum number of transaction retries reached - database problems?";
}

sub do_unlink {
   unlink $_[0];
}

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

   utf8::downgrade $file;
   utf8::downgrade $data;
   open my $fh, ">:raw", CFPlus::DB::path_of $file
      or return;
   print $fh $data;
   close $fh;

   1
}

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

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

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

         unless (eval { open_db }) {
            eval { File::Path::rmtree $DB_HOME };
            open_db;
         }

         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 $cb = CFPlus::DB::Server->can ("do_$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;
         }
      };

      my $error = $@;

      eval {
         undef %DB_TABLE;
         undef $DB_ENV;

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

      CFPlus::_exit 0;
   }

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

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

   $fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', cb => \&fh_read);

   sync_tick;
}

sub stop {
   close $FH;
}

1;

=back

=head1 AUTHOR

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

=cut

Revision:	1.9
Committed:	Thu Jul 12 17:56:51 2007 UTC (16 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.8:	+47 -3 lines
Log Message:	preliminary per-region music
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3	root	1.9	CFPlus::DB - async. database and filesystem access for cfplus
4	root	1.1
5			=head1 SYNOPSIS
6
7			use CFPlus::DB;
8
9			=head1 DESCRIPTION
10
11			=over 4
12
13			=cut
14
15			package CFPlus::DB;
16
17			use strict;
18			use utf8;
19
20			use Carp ();
21			use AnyEvent ();
22	root	1.5	use Storable ();
23	root	1.9	use Config;
24	root	1.1
25	root	1.3	use CFPlus;
26
27	root	1.9	our $DB_HOME = "$Crossfire::VARDIR/cfplus-$BerkeleyDB::db_version-$Config{archname}";
28
29			sub path_of($) {
30			"$DB_HOME/data-$_[0]"
31			}
32
33	root	1.1	sub sync {
34			# for debugging
35			#CFPlus::DB::Server::req (sync => sub { });
36			CFPlus::DB::Server::sync ();
37			}
38
39	root	1.9	sub exists($$$) {
40			CFPlus::DB::Server::req (exists => @_);
41			}
42
43	root	1.1	sub get($$$) {
44			CFPlus::DB::Server::req (get => @_);
45			}
46
47			sub put($$$$) {
48			CFPlus::DB::Server::req (put => @_);
49			}
50
51	root	1.9	sub unlink($$) {
52			CFPlus::DB::Server::req (unlink => @_);
53			}
54
55			sub write_file($$$) {
56			CFPlus::DB::Server::req (write_file => @_);
57			}
58
59	root	1.1	our $tilemap;
60
61			sub get_tile_id_sync($) {
62			my ($hash) = @_;
63
64			# fetch the full face table first
65			unless ($tilemap) {
66			CFPlus::DB::Server::req (table => facemap => sub { $tilemap = $_[0] });
67			sync;
68			}
69
70			$tilemap->{$hash} \|\|= do {
71			my $id;
72			CFPlus::DB::Server::req (get_tile_id => $hash, sub { $id = $_[0] });
73			sync;
74			$id
75			}
76			}
77
78			package CFPlus::DB::Server;
79
80			use strict;
81
82			use Fcntl;
83			use BerkeleyDB;
84
85			our $DB_ENV;
86			our $DB_STATE;
87			our %DB_TABLE;
88
89			sub open_db {
90			mkdir $DB_HOME, 0777;
91			my $recover = $BerkeleyDB::db_version >= 4.4
92			? eval "DB_REGISTER \| DB_RECOVER"
93			: 0;
94
95			$DB_ENV = new BerkeleyDB::Env
96			-Home => $DB_HOME,
97			-Cachesize => 8_000_000,
98			-ErrFile => "$DB_HOME/errorlog.txt",
99			# -ErrPrefix => "DATABASE",
100			-Verbose => 1,
101			-Flags => DB_CREATE \| DB_RECOVER \| DB_INIT_MPOOL \| DB_INIT_LOCK \| DB_INIT_TXN \| $recover,
102			-SetFlags => DB_AUTO_COMMIT \| DB_LOG_AUTOREMOVE,
103			or die "unable to create/open database home $DB_HOME: $BerkeleyDB::Error";
104
105			1
106			}
107
108			sub table($) {
109			$DB_TABLE{$_[0]} \|\|= do {
110			my ($table) = @_;
111
112			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
113
114			new BerkeleyDB::Btree
115			-Env => $DB_ENV,
116			-Filename => $table,
117			# -Filename => "database",
118			# -Subname => $table,
119			-Property => DB_CHKSUM,
120			-Flags => DB_CREATE \| DB_UPGRADE,
121			or die "unable to create/open database table $_[0]: $BerkeleyDB::Error"
122			}
123			}
124
125	root	1.4	our $SYNC_INTERVAL = 60;
126	root	1.1
127			our %CB;
128			our $FH;
129			our $ID = "aaa0";
130			our ($fh_r_watcher, $fh_w_watcher);
131			our $sync_timer;
132			our $write_buf;
133			our $read_buf;
134
135			sub fh_write {
136			my $len = syswrite $FH, $write_buf;
137
138			substr $write_buf, 0, $len, "";
139
140			undef $fh_w_watcher
141			unless length $write_buf;
142			}
143
144			sub fh_read {
145			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
146
147			die "FATAL: database process died\n"
148			if $status == 0 && defined $status;
149
150			while () {
151			return if 4 > length $read_buf;
152			my $len = unpack "N", $read_buf;
153
154			return if $len + 4 > length $read_buf;
155
156			substr $read_buf, 0, 4, "";
157			my $res = Storable::thaw substr $read_buf, 0, $len, "";
158
159			my ($id, @args) = @$res;
160			(delete $CB{$id})->(@args);
161			}
162			}
163
164			sub sync {
165			# biggest mess evarr
166			my $fds; (vec $fds, fileno $FH, 1) = 1;
167
168			while (1 < scalar keys %CB) {
169			my $r = $fds;
170			my $w = length $write_buf ? $fds : undef;
171			select $r, $w, undef, undef;
172
173			fh_write if vec $w, fileno $FH, 1;
174			fh_read if vec $r, fileno $FH, 1;
175			}
176			}
177
178			sub req {
179			my ($type, @args) = @_;
180			my $cb = pop @args;
181
182			my $id = ++$ID;
183			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
184			$CB{$id} = $cb;
185
186			$fh_w_watcher = AnyEvent->io (fh => $FH, poll => 'w', cb => \&fh_write);
187			}
188
189			sub sync_tick {
190			req "sync", sub { };
191			$sync_timer = AnyEvent->timer (after => $SYNC_INTERVAL, cb => \&sync_tick);
192			}
193
194			sub do_sync {
195			$DB_ENV->txn_checkpoint (0, 0, 0);
196			()
197			}
198
199	root	1.9	sub do_exists {
200			my ($db, $key) = @_;
201
202			utf8::downgrade $key;
203			my $data;
204			(table $db)->db_get ($key, $data) == 0
205			? length $data
206			: ()
207			}
208
209	root	1.1	sub do_get {
210			my ($db, $key) = @_;
211
212	root	1.5	utf8::downgrade $key;
213	root	1.1	my $data;
214			(table $db)->db_get ($key, $data) == 0
215			? $data
216			: ()
217			}
218
219			sub do_put {
220			my ($db, $key, $data) = @_;
221
222	root	1.5	utf8::downgrade $key;
223			utf8::downgrade $data;
224	root	1.1	(table $db)->db_put ($key => $data)
225			}
226
227			sub do_table {
228			my ($db) = @_;
229
230			$db = table $db;
231
232			my $cursor = $db->db_cursor;
233			my %kv;
234			my ($k, $v);
235			$kv{$k} = $v while $cursor->c_get ($k, $v, BerkeleyDB::DB_NEXT) == 0;
236
237			\%kv
238			}
239
240			sub do_get_tile_id {
241			my ($hash) = @_;
242
243			my $id;
244			my $table = table "facemap";
245
246			return $id
247			if $table->db_get ($hash, $id) == 0;
248
249			for (1..100) {
250			my $txn = $DB_ENV->txn_begin;
251			my $status = $table->db_get (id => $id);
252			if ($status == 0 \|\| $status == BerkeleyDB::DB_NOTFOUND) {
253			$id = ($id \|\| 64) + 1;
254			if ($table->db_put (id => $id) == 0
255			&& $table->db_put ($hash => $id) == 0) {
256			$txn->txn_commit;
257
258			return $id;
259			}
260			}
261			$txn->txn_abort;
262			}
263
264			die "maximum number of transaction retries reached - database problems?";
265			}
266
267	root	1.9	sub do_unlink {
268			unlink $_[0];
269			}
270
271			sub do_write_file {
272			my ($file, $data) = @_;
273
274			utf8::downgrade $file;
275			utf8::downgrade $data;
276			open my $fh, ">:raw", CFPlus::DB::path_of $file
277			or return;
278			print $fh $data;
279			close $fh;
280
281			1
282			}
283
284	root	1.1	sub run {
285			($FH, my $fh) = CFPlus::socketpipe;
286
287			my $oldfh = select $FH; $\| = 1; select $oldfh;
288			my $oldfh = select $fh; $\| = 1; select $oldfh;
289
290			my $pid = fork;
291
292			if (defined $pid && !$pid) {
293			local $SIG{__DIE__};
294			eval {
295			close $FH;
296
297			unless (eval { open_db }) {
298	root	1.6	eval { File::Path::rmtree $DB_HOME };
299	root	1.1	open_db;
300			}
301
302			while () {
303			4 == read $fh, my $len, 4
304			or last;
305			$len = unpack "N", $len;
306			$len == read $fh, my $req, $len
307			or die "unexpected eof while reading request";
308
309			$req = Storable::thaw $req;
310
311			my ($id, $type, @args) = @$req;
312			my $cb = CFPlus::DB::Server->can ("do_$type")
313			or die "$type: unknown database request type\n";
314			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
315			(syswrite $fh, $res) == length $res
316			or die;
317			}
318			};
319
320			my $error = $@;
321
322			eval {
323			undef %DB_TABLE;
324			undef $DB_ENV;
325
326			Storable::store_fd [die => $error], $fh;
327			};
328
329			CFPlus::_exit 0;
330			}
331
332			close $fh;
333	root	1.3	CFPlus::fh_nonblocking $FH, 1;
334	root	1.1
335	root	1.2	$CB{die} = sub { die shift };
336	root	1.1
337			$fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', cb => \&fh_read);
338
339			sync_tick;
340			}
341
342	root	1.6	sub stop {
343			close $FH;
344			}
345
346	root	1.1	1;
347
348			=back
349
350			=head1 AUTHOR
351
352			Marc Lehmann <schmorp@schmorp.de>
353			http://home.schmorp.de/
354
355			=cut
356