Deliantra-Client/DC/DB.pm

=head1 NAME

CFPlus::DB - async. database 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 (); # finally

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

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

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

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 $DB_HOME = "$Crossfire::VARDIR/cfplus";
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 = 6;

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

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

sub do_put {
   my ($db, $key, $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 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 }) {
            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;
   fcntl $FH, F_SETFL, O_NONBLOCK;

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

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

   sync_tick;
}

1;

=back

=head1 AUTHOR

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

=cut

Revision:	1.2
Committed:	Fri Apr 6 08:09:43 2007 UTC (17 years, 2 months ago) by root
Branch:	MAIN
Changes since 1.1:	+1 -3 lines
Log Message:	- optimise mapcache tile loading quite a bit to avoid loading the same tile again and again. - only request mapcache tiles serially, to avoid starving foreground requests.
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			CFPlus::DB - async. database access for cfplus
4
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			use Storable (); # finally
23
24			sub sync {
25			# for debugging
26			#CFPlus::DB::Server::req (sync => sub { });
27			CFPlus::DB::Server::sync ();
28			}
29
30			sub get($$$) {
31			CFPlus::DB::Server::req (get => @_);
32			}
33
34			sub put($$$$) {
35			CFPlus::DB::Server::req (put => @_);
36			}
37
38			our $tilemap;
39
40			sub get_tile_id_sync($) {
41			my ($hash) = @_;
42
43			# fetch the full face table first
44			unless ($tilemap) {
45			CFPlus::DB::Server::req (table => facemap => sub { $tilemap = $_[0] });
46			sync;
47			}
48
49			$tilemap->{$hash} \|\|= do {
50			my $id;
51			CFPlus::DB::Server::req (get_tile_id => $hash, sub { $id = $_[0] });
52			sync;
53			$id
54			}
55			}
56
57			package CFPlus::DB::Server;
58
59			use strict;
60
61			use Fcntl;
62			use BerkeleyDB;
63
64			our $DB_HOME = "$Crossfire::VARDIR/cfplus";
65			our $DB_ENV;
66			our $DB_STATE;
67			our %DB_TABLE;
68
69			sub open_db {
70			mkdir $DB_HOME, 0777;
71			my $recover = $BerkeleyDB::db_version >= 4.4
72			? eval "DB_REGISTER \| DB_RECOVER"
73			: 0;
74
75			$DB_ENV = new BerkeleyDB::Env
76			-Home => $DB_HOME,
77			-Cachesize => 8_000_000,
78			-ErrFile => "$DB_HOME/errorlog.txt",
79			# -ErrPrefix => "DATABASE",
80			-Verbose => 1,
81			-Flags => DB_CREATE \| DB_RECOVER \| DB_INIT_MPOOL \| DB_INIT_LOCK \| DB_INIT_TXN \| $recover,
82			-SetFlags => DB_AUTO_COMMIT \| DB_LOG_AUTOREMOVE,
83			or die "unable to create/open database home $DB_HOME: $BerkeleyDB::Error";
84
85			1
86			}
87
88			sub table($) {
89			$DB_TABLE{$_[0]} \|\|= do {
90			my ($table) = @_;
91
92			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
93
94			new BerkeleyDB::Btree
95			-Env => $DB_ENV,
96			-Filename => $table,
97			# -Filename => "database",
98			# -Subname => $table,
99			-Property => DB_CHKSUM,
100			-Flags => DB_CREATE \| DB_UPGRADE,
101			or die "unable to create/open database table $_[0]: $BerkeleyDB::Error"
102			}
103			}
104
105			our $SYNC_INTERVAL = 6;
106
107			our %CB;
108			our $FH;
109			our $ID = "aaa0";
110			our ($fh_r_watcher, $fh_w_watcher);
111			our $sync_timer;
112			our $write_buf;
113			our $read_buf;
114
115			sub fh_write {
116			my $len = syswrite $FH, $write_buf;
117
118			substr $write_buf, 0, $len, "";
119
120			undef $fh_w_watcher
121			unless length $write_buf;
122			}
123
124			sub fh_read {
125			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
126
127			die "FATAL: database process died\n"
128			if $status == 0 && defined $status;
129
130			while () {
131			return if 4 > length $read_buf;
132			my $len = unpack "N", $read_buf;
133
134			return if $len + 4 > length $read_buf;
135
136			substr $read_buf, 0, 4, "";
137			my $res = Storable::thaw substr $read_buf, 0, $len, "";
138
139			my ($id, @args) = @$res;
140			(delete $CB{$id})->(@args);
141			}
142			}
143
144			sub sync {
145			# biggest mess evarr
146			my $fds; (vec $fds, fileno $FH, 1) = 1;
147
148			while (1 < scalar keys %CB) {
149			my $r = $fds;
150			my $w = length $write_buf ? $fds : undef;
151			select $r, $w, undef, undef;
152
153			fh_write if vec $w, fileno $FH, 1;
154			fh_read if vec $r, fileno $FH, 1;
155			}
156			}
157
158			sub req {
159			my ($type, @args) = @_;
160			my $cb = pop @args;
161
162			my $id = ++$ID;
163			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
164			$CB{$id} = $cb;
165
166			$fh_w_watcher = AnyEvent->io (fh => $FH, poll => 'w', cb => \&fh_write);
167			}
168
169			sub sync_tick {
170			req "sync", sub { };
171			$sync_timer = AnyEvent->timer (after => $SYNC_INTERVAL, cb => \&sync_tick);
172			}
173
174			sub do_sync {
175			$DB_ENV->txn_checkpoint (0, 0, 0);
176			()
177			}
178
179			sub do_get {
180			my ($db, $key) = @_;
181
182			my $data;
183			(table $db)->db_get ($key, $data) == 0
184			? $data
185			: ()
186			}
187
188			sub do_put {
189			my ($db, $key, $data) = @_;
190
191			(table $db)->db_put ($key => $data)
192			}
193
194			sub do_table {
195			my ($db) = @_;
196
197			$db = table $db;
198
199			my $cursor = $db->db_cursor;
200			my %kv;
201			my ($k, $v);
202			$kv{$k} = $v while $cursor->c_get ($k, $v, BerkeleyDB::DB_NEXT) == 0;
203
204			\%kv
205			}
206
207			sub do_get_tile_id {
208			my ($hash) = @_;
209
210			my $id;
211			my $table = table "facemap";
212
213			return $id
214			if $table->db_get ($hash, $id) == 0;
215
216			for (1..100) {
217			my $txn = $DB_ENV->txn_begin;
218			my $status = $table->db_get (id => $id);
219			if ($status == 0 \|\| $status == BerkeleyDB::DB_NOTFOUND) {
220			$id = ($id \|\| 64) + 1;
221			if ($table->db_put (id => $id) == 0
222			&& $table->db_put ($hash => $id) == 0) {
223			$txn->txn_commit;
224
225			return $id;
226			}
227			}
228			$txn->txn_abort;
229			}
230
231			die "maximum number of transaction retries reached - database problems?";
232			}
233
234			sub run {
235			($FH, my $fh) = CFPlus::socketpipe;
236
237			my $oldfh = select $FH; $\| = 1; select $oldfh;
238			my $oldfh = select $fh; $\| = 1; select $oldfh;
239
240			my $pid = fork;
241
242			if (defined $pid && !$pid) {
243			local $SIG{__DIE__};
244			eval {
245			close $FH;
246
247			unless (eval { open_db }) {
248			File::Path::rmtree $DB_HOME;
249			open_db;
250			}
251
252			while () {
253			4 == read $fh, my $len, 4
254			or last;
255			$len = unpack "N", $len;
256			$len == read $fh, my $req, $len
257			or die "unexpected eof while reading request";
258
259			$req = Storable::thaw $req;
260
261			my ($id, $type, @args) = @$req;
262			my $cb = CFPlus::DB::Server->can ("do_$type")
263			or die "$type: unknown database request type\n";
264			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
265			(syswrite $fh, $res) == length $res
266			or die;
267			}
268			};
269
270			my $error = $@;
271
272			eval {
273			undef %DB_TABLE;
274			undef $DB_ENV;
275
276			Storable::store_fd [die => $error], $fh;
277			};
278
279			CFPlus::_exit 0;
280			}
281
282			close $fh;
283			fcntl $FH, F_SETFL, O_NONBLOCK;
284
285	root	1.2	$CB{die} = sub { die shift };
286	root	1.1
287			$fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', cb => \&fh_read);
288
289			sync_tick;
290			}
291
292			1;
293
294			=back
295
296			=head1 AUTHOR
297
298			Marc Lehmann <schmorp@schmorp.de>
299			http://home.schmorp.de/
300
301			=cut
302