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/cvs/deliantra/Deliantra-Client/DC/DB.pm
Revision: 1.11
Committed: Sat Jul 14 12:05:53 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
Changes since 1.10: +17 -2 lines
Log Message:
greatly enhance and improve music selection algorithm and reduce database load

File Contents

# Content
1 =head1 NAME
2
3 CFPlus::DB - async. database and filesystem 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 ();
23 use Config;
24
25 use CFPlus;
26
27 our $DB_HOME = "$Crossfire::VARDIR/cfplus-$BerkeleyDB::db_version-$Config{archname}";
28
29 sub path_of_res($) {
30 "$DB_HOME/res-data-$_[0]"
31 }
32
33 sub sync {
34 # for debugging
35 #CFPlus::DB::Server::req (sync => sub { });
36 CFPlus::DB::Server::sync ();
37 }
38
39 sub exists($$$) {
40 CFPlus::DB::Server::req (exists => @_);
41 }
42
43 sub get($$$) {
44 CFPlus::DB::Server::req (get => @_);
45 }
46
47 sub put($$$$) {
48 CFPlus::DB::Server::req (put => @_);
49 }
50
51 sub unlink($$) {
52 CFPlus::DB::Server::req (unlink => @_);
53 }
54
55 sub write_file($$$) {
56 CFPlus::DB::Server::req (write_file => @_);
57 }
58
59 sub prefetch_file($$$) {
60 CFPlus::DB::Server::req (prefetch_file => @_);
61 }
62
63 our $tilemap;
64
65 sub get_tile_id_sync($) {
66 my ($hash) = @_;
67
68 # fetch the full face table first
69 unless ($tilemap) {
70 CFPlus::DB::Server::req (table => facemap => sub { $tilemap = $_[0] });
71 sync;
72 }
73
74 $tilemap->{$hash} ||= do {
75 my $id;
76 CFPlus::DB::Server::req (get_tile_id => $hash, sub { $id = $_[0] });
77 sync;
78 $id
79 }
80 }
81
82 package CFPlus::DB::Server;
83
84 use strict;
85
86 use Fcntl;
87 use BerkeleyDB;
88
89 our $DB_ENV;
90 our $DB_STATE;
91 our %DB_TABLE;
92
93 sub open_db {
94 mkdir $DB_HOME, 0777;
95 my $recover = $BerkeleyDB::db_version >= 4.4
96 ? eval "DB_REGISTER | DB_RECOVER"
97 : 0;
98
99 $DB_ENV = new BerkeleyDB::Env
100 -Home => $DB_HOME,
101 -Cachesize => 8_000_000,
102 -ErrFile => "$DB_HOME/errorlog.txt",
103 # -ErrPrefix => "DATABASE",
104 -Verbose => 1,
105 -Flags => DB_CREATE | DB_RECOVER | DB_INIT_MPOOL | DB_INIT_LOCK | DB_INIT_TXN | $recover,
106 -SetFlags => DB_AUTO_COMMIT | DB_LOG_AUTOREMOVE,
107 or die "unable to create/open database home $DB_HOME: $BerkeleyDB::Error";
108
109 1
110 }
111
112 sub table($) {
113 $DB_TABLE{$_[0]} ||= do {
114 my ($table) = @_;
115
116 $table =~ s/([^a-zA-Z0-9_\-])/sprintf "=%x=", ord $1/ge;
117
118 new BerkeleyDB::Btree
119 -Env => $DB_ENV,
120 -Filename => $table,
121 # -Filename => "database",
122 # -Subname => $table,
123 -Property => DB_CHKSUM,
124 -Flags => DB_CREATE | DB_UPGRADE,
125 or die "unable to create/open database table $_[0]: $BerkeleyDB::Error"
126 }
127 }
128
129 our $SYNC_INTERVAL = 60;
130
131 our %CB;
132 our $FH;
133 our $ID = "aaa0";
134 our ($fh_r_watcher, $fh_w_watcher);
135 our $sync_timer;
136 our $write_buf;
137 our $read_buf;
138
139 sub fh_write {
140 my $len = syswrite $FH, $write_buf;
141
142 substr $write_buf, 0, $len, "";
143
144 undef $fh_w_watcher
145 unless length $write_buf;
146 }
147
148 sub fh_read {
149 my $status = sysread $FH, $read_buf, 16384, length $read_buf;
150
151 die "FATAL: database process died\n"
152 if $status == 0 && defined $status;
153
154 while () {
155 return if 4 > length $read_buf;
156 my $len = unpack "N", $read_buf;
157
158 return if $len + 4 > length $read_buf;
159
160 substr $read_buf, 0, 4, "";
161 my $res = Storable::thaw substr $read_buf, 0, $len, "";
162
163 my ($id, @args) = @$res;
164 (delete $CB{$id})->(@args);
165 }
166 }
167
168 sub sync {
169 # biggest mess evarr
170 my $fds; (vec $fds, fileno $FH, 1) = 1;
171
172 while (1 < scalar keys %CB) {
173 my $r = $fds;
174 my $w = length $write_buf ? $fds : undef;
175 select $r, $w, undef, undef;
176
177 fh_write if vec $w, fileno $FH, 1;
178 fh_read if vec $r, fileno $FH, 1;
179 }
180 }
181
182 sub req {
183 my ($type, @args) = @_;
184 my $cb = pop @args;
185
186 my $id = ++$ID;
187 $write_buf .= pack "N/a*", Storable::freeze [$id, $type, @args];
188 $CB{$id} = $cb;
189
190 $fh_w_watcher = AnyEvent->io (fh => $FH, poll => 'w', cb => \&fh_write);
191 }
192
193 sub sync_tick {
194 req "sync", sub { };
195 $sync_timer = AnyEvent->timer (after => $SYNC_INTERVAL, cb => \&sync_tick);
196 }
197
198 sub do_sync {
199 $DB_ENV->txn_checkpoint (0, 0, 0);
200 ()
201 }
202
203 sub do_exists {
204 my ($db, $key) = @_;
205
206 utf8::downgrade $key;
207 my $data;
208 (table $db)->db_get ($key, $data) == 0
209 ? length $data
210 : ()
211 }
212
213 sub do_get {
214 my ($db, $key) = @_;
215
216 utf8::downgrade $key;
217 my $data;
218 (table $db)->db_get ($key, $data) == 0
219 ? $data
220 : ()
221 }
222
223 sub do_put {
224 my ($db, $key, $data) = @_;
225
226 utf8::downgrade $key;
227 utf8::downgrade $data;
228 (table $db)->db_put ($key => $data)
229 }
230
231 sub do_table {
232 my ($db) = @_;
233
234 $db = table $db;
235
236 my $cursor = $db->db_cursor;
237 my %kv;
238 my ($k, $v);
239 $kv{$k} = $v while $cursor->c_get ($k, $v, BerkeleyDB::DB_NEXT) == 0;
240
241 \%kv
242 }
243
244 sub do_get_tile_id {
245 my ($hash) = @_;
246
247 my $id;
248 my $table = table "facemap";
249
250 return $id
251 if $table->db_get ($hash, $id) == 0;
252
253 for (1..100) {
254 my $txn = $DB_ENV->txn_begin;
255 my $status = $table->db_get (id => $id);
256 if ($status == 0 || $status == BerkeleyDB::DB_NOTFOUND) {
257 $id = ($id || 64) + 1;
258 if ($table->db_put (id => $id) == 0
259 && $table->db_put ($hash => $id) == 0) {
260 $txn->txn_commit;
261
262 return $id;
263 }
264 }
265 $txn->txn_abort;
266 }
267
268 die "maximum number of transaction retries reached - database problems?";
269 }
270
271 sub do_unlink {
272 unlink $_[0];
273 }
274
275 sub do_write_file {
276 my ($file, $data) = @_;
277
278 utf8::downgrade $file;
279 utf8::downgrade $data;
280 open my $fh, ">:raw", $file
281 or return;
282 print $fh $data;
283 close $fh;
284
285 1
286 }
287
288 sub do_prefetch_file {
289 my ($file, $size) = @_;
290
291 utf8::downgrade $file;
292 open my $fh, "<:raw", $file
293 or return;
294 sysread $fh, my $buf, $size;
295
296 1
297 }
298
299 sub run {
300 ($FH, my $fh) = CFPlus::socketpipe;
301
302 my $oldfh = select $FH; $| = 1; select $oldfh;
303 my $oldfh = select $fh; $| = 1; select $oldfh;
304
305 my $pid = fork;
306
307 if (defined $pid && !$pid) {
308 local $SIG{__DIE__};
309 eval {
310 close $FH;
311
312 unless (eval { open_db }) {
313 eval { File::Path::rmtree $DB_HOME };
314 open_db;
315 }
316
317 while () {
318 4 == read $fh, my $len, 4
319 or last;
320 $len = unpack "N", $len;
321 $len == read $fh, my $req, $len
322 or die "unexpected eof while reading request";
323
324 $req = Storable::thaw $req;
325
326 my ($id, $type, @args) = @$req;
327 my $cb = CFPlus::DB::Server->can ("do_$type")
328 or die "$type: unknown database request type\n";
329 my $res = pack "N/a*", Storable::freeze [$id, $cb->(@args)];
330 (syswrite $fh, $res) == length $res
331 or die;
332 }
333 };
334
335 my $error = $@;
336
337 eval {
338 undef %DB_TABLE;
339 undef $DB_ENV;
340
341 Storable::store_fd [die => $error], $fh;
342 };
343
344 CFPlus::_exit 0;
345 }
346
347 close $fh;
348 CFPlus::fh_nonblocking $FH, 1;
349
350 $CB{die} = sub { die shift };
351
352 $fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', cb => \&fh_read);
353
354 sync_tick;
355 }
356
357 sub stop {
358 close $FH;
359 }
360
361 1;
362
363 =back
364
365 =head1 AUTHOR
366
367 Marc Lehmann <schmorp@schmorp.de>
368 http://home.schmorp.de/
369
370 =cut
371