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/cvs/deliantra/Deliantra-Client/DC/DB.pm
Revision: 1.12
Committed: Tue Jul 24 04:54:47 2007 UTC (16 years, 10 months ago) by root
Branch: MAIN
Changes since 1.11: +2 -1 lines
Log Message:
welcome to fxix protocol version 3, with uniform handling over all resources

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 utf8::downgrade $_[0]; # bug in unpack "H*"
31 "$DB_HOME/res-data-" . unpack "H*", $_[0]
32 }
33
34 sub sync {
35 # for debugging
36 #CFPlus::DB::Server::req (sync => sub { });
37 CFPlus::DB::Server::sync ();
38 }
39
40 sub exists($$$) {
41 CFPlus::DB::Server::req (exists => @_);
42 }
43
44 sub get($$$) {
45 CFPlus::DB::Server::req (get => @_);
46 }
47
48 sub put($$$$) {
49 CFPlus::DB::Server::req (put => @_);
50 }
51
52 sub unlink($$) {
53 CFPlus::DB::Server::req (unlink => @_);
54 }
55
56 sub write_file($$$) {
57 CFPlus::DB::Server::req (write_file => @_);
58 }
59
60 sub prefetch_file($$$) {
61 CFPlus::DB::Server::req (prefetch_file => @_);
62 }
63
64 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 our $SYNC_INTERVAL = 60;
131
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 $DB_ENV->txn_checkpoint (0, 0, 0);
201 ()
202 }
203
204 sub do_exists {
205 my ($db, $key) = @_;
206
207 utf8::downgrade $key;
208 my $data;
209 (table $db)->db_get ($key, $data) == 0
210 ? length $data
211 : ()
212 }
213
214 sub do_get {
215 my ($db, $key) = @_;
216
217 utf8::downgrade $key;
218 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 utf8::downgrade $key;
228 utf8::downgrade $data;
229 (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 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 open my $fh, ">:raw", $file
282 or return;
283 print $fh $data;
284 close $fh;
285
286 1
287 }
288
289 sub do_prefetch_file {
290 my ($file, $size) = @_;
291
292 utf8::downgrade $file;
293 open my $fh, "<:raw", $file
294 or return;
295 sysread $fh, my $buf, $size;
296
297 1
298 }
299
300 sub run {
301 ($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 eval { File::Path::rmtree $DB_HOME };
315 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 CFPlus::fh_nonblocking $FH, 1;
350
351 $CB{die} = sub { die shift };
352
353 $fh_r_watcher = AnyEvent->io (fh => $FH, poll => 'r', cb => \&fh_read);
354
355 sync_tick;
356 }
357
358 sub stop {
359 close $FH;
360 }
361
362 1;
363
364 =back
365
366 =head1 AUTHOR
367
368 Marc Lehmann <schmorp@schmorp.de>
369 http://home.schmorp.de/
370
371 =cut
372