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_res($) {
   utf8::downgrade $_[0]; # bug in unpack "H*"
   "$DB_HOME/res-data-" . unpack "H*", $_[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 => @_);
}

sub prefetch_file($$$) {
   CFPlus::DB::Server::req (prefetch_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", $file
      or return;
   print $fh $data;
   close $fh;

   1
}

sub do_prefetch_file {
   my ($file, $size) = @_;

   utf8::downgrade $file;
   open my $fh, "<:raw", $file
      or return;
   sysread $fh, my $buf, $size;

   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', nice => 1, cb => \&fh_read);

   sync_tick;
}

sub stop {
   close $FH;
}

1;

=back

=head1 AUTHOR

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

=cut

Revision:	1.13
Committed:	Sun Jul 29 04:14:45 2007 UTC (16 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.12:	+1 -1 lines
Log Message:	more complete api, got rid of most retvals
#	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	root	1.11	sub path_of_res($) {
30	root	1.12	utf8::downgrade $_[0]; # bug in unpack "H*"
31			"$DB_HOME/res-data-" . unpack "H*", $_[0]
32	root	1.9	}
33
34	root	1.1	sub sync {
35			# for debugging
36			#CFPlus::DB::Server::req (sync => sub { });
37			CFPlus::DB::Server::sync ();
38			}
39
40	root	1.9	sub exists($$$) {
41			CFPlus::DB::Server::req (exists => @_);
42			}
43
44	root	1.1	sub get($$$) {
45			CFPlus::DB::Server::req (get => @_);
46			}
47
48			sub put($$$$) {
49			CFPlus::DB::Server::req (put => @_);
50			}
51
52	root	1.9	sub unlink($$) {
53			CFPlus::DB::Server::req (unlink => @_);
54			}
55
56			sub write_file($$$) {
57			CFPlus::DB::Server::req (write_file => @_);
58			}
59
60	root	1.11	sub prefetch_file($$$) {
61			CFPlus::DB::Server::req (prefetch_file => @_);
62			}
63
64	root	1.1	our $tilemap;
65
66			sub get_tile_id_sync($) {
67			my ($hash) = @_;
68
69			# fetch the full face table first
70			unless ($tilemap) {
71			CFPlus::DB::Server::req (table => facemap => sub { $tilemap = $_[0] });
72			sync;
73			}
74
75			$tilemap->{$hash} \|\|= do {
76			my $id;
77			CFPlus::DB::Server::req (get_tile_id => $hash, sub { $id = $_[0] });
78			sync;
79			$id
80			}
81			}
82
83			package CFPlus::DB::Server;
84
85			use strict;
86
87			use Fcntl;
88			use BerkeleyDB;
89
90			our $DB_ENV;
91			our $DB_STATE;
92			our %DB_TABLE;
93
94			sub open_db {
95			mkdir $DB_HOME, 0777;
96			my $recover = $BerkeleyDB::db_version >= 4.4
97			? eval "DB_REGISTER \| DB_RECOVER"
98			: 0;
99
100			$DB_ENV = new BerkeleyDB::Env
101			-Home => $DB_HOME,
102			-Cachesize => 8_000_000,
103			-ErrFile => "$DB_HOME/errorlog.txt",
104			# -ErrPrefix => "DATABASE",
105			-Verbose => 1,
106			-Flags => DB_CREATE \| DB_RECOVER \| DB_INIT_MPOOL \| DB_INIT_LOCK \| DB_INIT_TXN \| $recover,
107			-SetFlags => DB_AUTO_COMMIT \| DB_LOG_AUTOREMOVE,
108			or die "unable to create/open database home $DB_HOME: $BerkeleyDB::Error";
109
110			1
111			}
112
113			sub table($) {
114			$DB_TABLE{$_[0]} \|\|= do {
115			my ($table) = @_;
116
117			$table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
118
119			new BerkeleyDB::Btree
120			-Env => $DB_ENV,
121			-Filename => $table,
122			# -Filename => "database",
123			# -Subname => $table,
124			-Property => DB_CHKSUM,
125			-Flags => DB_CREATE \| DB_UPGRADE,
126			or die "unable to create/open database table $_[0]: $BerkeleyDB::Error"
127			}
128			}
129
130	root	1.4	our $SYNC_INTERVAL = 60;
131	root	1.1
132			our %CB;
133			our $FH;
134			our $ID = "aaa0";
135			our ($fh_r_watcher, $fh_w_watcher);
136			our $sync_timer;
137			our $write_buf;
138			our $read_buf;
139
140			sub fh_write {
141			my $len = syswrite $FH, $write_buf;
142
143			substr $write_buf, 0, $len, "";
144
145			undef $fh_w_watcher
146			unless length $write_buf;
147			}
148
149			sub fh_read {
150			my $status = sysread $FH, $read_buf, 16384, length $read_buf;
151
152			die "FATAL: database process died\n"
153			if $status == 0 && defined $status;
154
155			while () {
156			return if 4 > length $read_buf;
157			my $len = unpack "N", $read_buf;
158
159			return if $len + 4 > length $read_buf;
160
161			substr $read_buf, 0, 4, "";
162			my $res = Storable::thaw substr $read_buf, 0, $len, "";
163
164			my ($id, @args) = @$res;
165			(delete $CB{$id})->(@args);
166			}
167			}
168
169			sub sync {
170			# biggest mess evarr
171			my $fds; (vec $fds, fileno $FH, 1) = 1;
172
173			while (1 < scalar keys %CB) {
174			my $r = $fds;
175			my $w = length $write_buf ? $fds : undef;
176			select $r, $w, undef, undef;
177
178			fh_write if vec $w, fileno $FH, 1;
179			fh_read if vec $r, fileno $FH, 1;
180			}
181			}
182
183			sub req {
184			my ($type, @args) = @_;
185			my $cb = pop @args;
186
187			my $id = ++$ID;
188			$write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
189			$CB{$id} = $cb;
190
191			$fh_w_watcher = AnyEvent->io (fh => $FH, poll => 'w', cb => \&fh_write);
192			}
193
194			sub sync_tick {
195			req "sync", sub { };
196			$sync_timer = AnyEvent->timer (after => $SYNC_INTERVAL, cb => \&sync_tick);
197			}
198
199			sub do_sync {
200			$DB_ENV->txn_checkpoint (0, 0, 0);
201			()
202			}
203
204	root	1.9	sub do_exists {
205			my ($db, $key) = @_;
206
207			utf8::downgrade $key;
208			my $data;
209			(table $db)->db_get ($key, $data) == 0
210			? length $data
211			: ()
212			}
213
214	root	1.1	sub do_get {
215			my ($db, $key) = @_;
216
217	root	1.5	utf8::downgrade $key;
218	root	1.1	my $data;
219			(table $db)->db_get ($key, $data) == 0
220			? $data
221			: ()
222			}
223
224			sub do_put {
225			my ($db, $key, $data) = @_;
226
227	root	1.5	utf8::downgrade $key;
228			utf8::downgrade $data;
229	root	1.1	(table $db)->db_put ($key => $data)
230			}
231
232			sub do_table {
233			my ($db) = @_;
234
235			$db = table $db;
236
237			my $cursor = $db->db_cursor;
238			my %kv;
239			my ($k, $v);
240			$kv{$k} = $v while $cursor->c_get ($k, $v, BerkeleyDB::DB_NEXT) == 0;
241
242			\%kv
243			}
244
245			sub do_get_tile_id {
246			my ($hash) = @_;
247
248			my $id;
249			my $table = table "facemap";
250
251			return $id
252			if $table->db_get ($hash, $id) == 0;
253
254			for (1..100) {
255			my $txn = $DB_ENV->txn_begin;
256			my $status = $table->db_get (id => $id);
257			if ($status == 0 \|\| $status == BerkeleyDB::DB_NOTFOUND) {
258			$id = ($id \|\| 64) + 1;
259			if ($table->db_put (id => $id) == 0
260			&& $table->db_put ($hash => $id) == 0) {
261			$txn->txn_commit;
262
263			return $id;
264			}
265			}
266			$txn->txn_abort;
267			}
268
269			die "maximum number of transaction retries reached - database problems?";
270			}
271
272	root	1.9	sub do_unlink {
273			unlink $_[0];
274			}
275
276			sub do_write_file {
277			my ($file, $data) = @_;
278
279			utf8::downgrade $file;
280			utf8::downgrade $data;
281	root	1.11	open my $fh, ">:raw", $file
282	root	1.9	or return;
283			print $fh $data;
284			close $fh;
285
286			1
287			}
288
289	root	1.11	sub do_prefetch_file {
290			my ($file, $size) = @_;
291
292			utf8::downgrade $file;
293			open my $fh, "<:raw", $file
294			or return;
295			sysread $fh, my $buf, $size;
296
297			1
298			}
299
300	root	1.1	sub run {
301			($FH, my $fh) = CFPlus::socketpipe;
302
303			my $oldfh = select $FH; $\| = 1; select $oldfh;
304			my $oldfh = select $fh; $\| = 1; select $oldfh;
305
306			my $pid = fork;
307
308			if (defined $pid && !$pid) {
309			local $SIG{__DIE__};
310			eval {
311			close $FH;
312
313			unless (eval { open_db }) {
314	root	1.6	eval { File::Path::rmtree $DB_HOME };
315	root	1.1	open_db;
316			}
317
318			while () {
319			4 == read $fh, my $len, 4
320			or last;
321			$len = unpack "N", $len;
322			$len == read $fh, my $req, $len
323			or die "unexpected eof while reading request";
324
325			$req = Storable::thaw $req;
326
327			my ($id, $type, @args) = @$req;
328			my $cb = CFPlus::DB::Server->can ("do_$type")
329			or die "$type: unknown database request type\n";
330			my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
331			(syswrite $fh, $res) == length $res
332			or die;
333			}
334			};
335
336			my $error = $@;
337
338			eval {
339			undef %DB_TABLE;
340			undef $DB_ENV;
341
342			Storable::store_fd [die => $error], $fh;
343			};
344
345			CFPlus::_exit 0;
346			}
347
348			close $fh;
349	root	1.3	CFPlus::fh_nonblocking $FH, 1;
350	root	1.1
351	root	1.2	$CB{die} = sub { die shift };
352	root	1.1
353	root	1.13	$fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', nice => 1, cb => \&fh_read);
354	root	1.1
355			sync_tick;
356			}
357
358	root	1.6	sub stop {
359			close $FH;
360			}
361
362	root	1.1	1;
363
364			=back
365
366			=head1 AUTHOR
367
368			Marc Lehmann <schmorp@schmorp.de>
369			http://home.schmorp.de/
370
371			=cut
372