Commit | Line | Data |
662db255 |
1 | package DBM::Deep::Engine; |
696cadb7 |
2 | |
3 | use 5.6.0; |
4 | |
5 | use strict; |
6 | |
7 | our $VERSION = q(0.99_03); |
8 | |
696cadb7 |
9 | use Scalar::Util (); |
10 | |
11 | # File-wide notes: |
8fbac729 |
12 | # * Every method in here assumes that the storage has been appropriately |
696cadb7 |
13 | # safeguarded. This can be anything from flock() to some sort of manual |
14 | # mutex. But, it's the caller's responsability to make sure that this has |
15 | # been done. |
16 | |
17 | # Setup file and tag signatures. These should never change. |
18 | sub SIG_FILE () { 'DPDB' } |
19 | sub SIG_HEADER () { 'h' } |
20 | sub SIG_INTERNAL () { 'i' } |
21 | sub SIG_HASH () { 'H' } |
22 | sub SIG_ARRAY () { 'A' } |
23 | sub SIG_NULL () { 'N' } |
24 | sub SIG_DATA () { 'D' } |
25 | sub SIG_INDEX () { 'I' } |
26 | sub SIG_BLIST () { 'B' } |
27 | sub SIG_FREE () { 'F' } |
28 | sub SIG_KEYS () { 'K' } |
29 | sub SIG_SIZE () { 1 } |
d58fd793 |
30 | sub STALE_SIZE () { 1 } |
696cadb7 |
31 | |
8fbac729 |
32 | # Please refer to the pack() documentation for further information |
33 | my %StP = ( |
b4e17919 |
34 | 1 => 'C', # Unsigned char value (no order specified, presumably ASCII) |
8fbac729 |
35 | 2 => 'n', # Unsigned short in "network" (big-endian) order |
36 | 4 => 'N', # Unsigned long in "network" (big-endian) order |
37 | 8 => 'Q', # Usigned quad (no order specified, presumably machine-dependent) |
c83524c6 |
38 | ); |
39 | |
7645a22a |
40 | ################################################################################ |
41 | |
696cadb7 |
42 | sub new { |
43 | my $class = shift; |
44 | my ($args) = @_; |
45 | |
46 | my $self = bless { |
c83524c6 |
47 | byte_size => 4, |
696cadb7 |
48 | |
c83524c6 |
49 | digest => undef, |
6a4f323c |
50 | hash_size => 16, # In bytes |
51 | hash_chars => 256, # Number of chars the algorithm uses per byte |
696cadb7 |
52 | max_buckets => 16, |
3976d8c9 |
53 | num_txns => 16, # HEAD plus 15 running txns |
8cb9205a |
54 | trans_id => 0, # Default to the HEAD |
696cadb7 |
55 | |
6f999f6e |
56 | entries => {}, # This is the list of entries for transactions |
696cadb7 |
57 | storage => undef, |
696cadb7 |
58 | }, $class; |
59 | |
60 | if ( defined $args->{pack_size} ) { |
61 | if ( lc $args->{pack_size} eq 'small' ) { |
c83524c6 |
62 | $args->{byte_size} = 2; |
696cadb7 |
63 | } |
64 | elsif ( lc $args->{pack_size} eq 'medium' ) { |
c83524c6 |
65 | $args->{byte_size} = 4; |
696cadb7 |
66 | } |
67 | elsif ( lc $args->{pack_size} eq 'large' ) { |
c83524c6 |
68 | $args->{byte_size} = 8; |
696cadb7 |
69 | } |
70 | else { |
71 | die "Unknown pack_size value: '$args->{pack_size}'\n"; |
72 | } |
73 | } |
74 | |
75 | # Grab the parameters we want to use |
76 | foreach my $param ( keys %$self ) { |
77 | next unless exists $args->{$param}; |
78 | $self->{$param} = $args->{$param}; |
79 | } |
696cadb7 |
80 | |
8fbac729 |
81 | $self->{byte_pack} = $StP{ $self->byte_size }; |
c83524c6 |
82 | |
696cadb7 |
83 | ## |
84 | # Number of buckets per blist before another level of indexing is |
85 | # done. Increase this value for slightly greater speed, but larger database |
86 | # files. DO NOT decrease this value below 16, due to risk of recursive |
87 | # reindex overrun. |
88 | ## |
89 | if ( $self->{max_buckets} < 16 ) { |
90 | warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n"; |
91 | $self->{max_buckets} = 16; |
92 | } |
93 | |
c83524c6 |
94 | if ( !$self->{digest} ) { |
95 | require Digest::MD5; |
96 | $self->{digest} = \&Digest::MD5::md5; |
97 | } |
98 | |
696cadb7 |
99 | return $self; |
100 | } |
101 | |
102 | ################################################################################ |
103 | |
104 | sub read_value { |
105 | my $self = shift; |
c9f02899 |
106 | my ($obj, $key) = @_; |
3976d8c9 |
107 | |
108 | # This will be a Reference sector |
c9f02899 |
109 | my $sector = $self->_load_sector( $obj->_base_offset ) |
76c68c87 |
110 | or return; |
3976d8c9 |
111 | |
8af340bf |
112 | if ( $sector->staleness != $obj->_staleness ) { |
113 | return; |
114 | } |
115 | |
3976d8c9 |
116 | my $key_md5 = $self->_apply_digest( $key ); |
117 | |
2432d6cc |
118 | my $value_sector = $sector->get_data_for({ |
119 | key_md5 => $key_md5, |
120 | allow_head => 1, |
121 | }); |
3976d8c9 |
122 | |
2432d6cc |
123 | unless ( $value_sector ) { |
4056dff7 |
124 | $value_sector = DBM::Deep::Engine::Sector::Null->new({ |
125 | engine => $self, |
126 | data => undef, |
127 | }); |
128 | |
2432d6cc |
129 | $sector->write_data({ |
130 | key_md5 => $key_md5, |
131 | key => $key, |
132 | value => $value_sector, |
133 | }); |
4056dff7 |
134 | } |
3976d8c9 |
135 | |
136 | return $value_sector->data; |
696cadb7 |
137 | } |
138 | |
84467b9f |
139 | sub get_classname { |
140 | my $self = shift; |
c9f02899 |
141 | my ($obj) = @_; |
84467b9f |
142 | |
143 | # This will be a Reference sector |
c9f02899 |
144 | my $sector = $self->_load_sector( $obj->_base_offset ) |
76c68c87 |
145 | or die "How did get_classname fail (no sector for '$obj')?!\n"; |
84467b9f |
146 | |
8af340bf |
147 | if ( $sector->staleness != $obj->_staleness ) { |
148 | return; |
149 | } |
150 | |
84467b9f |
151 | return $sector->get_classname; |
152 | } |
153 | |
696cadb7 |
154 | sub key_exists { |
155 | my $self = shift; |
c9f02899 |
156 | my ($obj, $key) = @_; |
c000ae6e |
157 | |
158 | # This will be a Reference sector |
c9f02899 |
159 | my $sector = $self->_load_sector( $obj->_base_offset ) |
76c68c87 |
160 | or return ''; |
c000ae6e |
161 | |
8af340bf |
162 | if ( $sector->staleness != $obj->_staleness ) { |
163 | return ''; |
164 | } |
165 | |
2432d6cc |
166 | my $data = $sector->get_data_for({ |
167 | key_md5 => $self->_apply_digest( $key ), |
168 | allow_head => 1, |
169 | }); |
c000ae6e |
170 | |
e86cef36 |
171 | # exists() returns 1 or '' for true/false. |
2432d6cc |
172 | return $data ? 1 : ''; |
696cadb7 |
173 | } |
174 | |
175 | sub delete_key { |
176 | my $self = shift; |
c9f02899 |
177 | my ($obj, $key) = @_; |
e86cef36 |
178 | |
c9f02899 |
179 | my $sector = $self->_load_sector( $obj->_base_offset ) |
76c68c87 |
180 | or return; |
e86cef36 |
181 | |
8af340bf |
182 | if ( $sector->staleness != $obj->_staleness ) { |
183 | return; |
184 | } |
185 | |
2432d6cc |
186 | return $sector->delete_key({ |
187 | key_md5 => $self->_apply_digest( $key ), |
188 | allow_head => 0, |
189 | }); |
696cadb7 |
190 | } |
191 | |
192 | sub write_value { |
193 | my $self = shift; |
c9f02899 |
194 | my ($obj, $key, $value) = @_; |
3976d8c9 |
195 | |
764e6cb9 |
196 | my $r = Scalar::Util::reftype( $value ) || ''; |
d49782fe |
197 | { |
198 | last if $r eq ''; |
199 | last if $r eq 'HASH'; |
200 | last if $r eq 'ARRAY'; |
201 | |
202 | DBM::Deep->_throw_error( |
203 | "Storage of references of type '$r' is not supported." |
204 | ); |
205 | } |
206 | |
764e6cb9 |
207 | my ($class, $type); |
68369f26 |
208 | if ( !defined $value ) { |
4eee718c |
209 | $class = 'DBM::Deep::Engine::Sector::Null'; |
68369f26 |
210 | } |
764e6cb9 |
211 | elsif ( $r eq 'ARRAY' || $r eq 'HASH' ) { |
d49782fe |
212 | if ( $r eq 'ARRAY' && tied(@$value) ) { |
25eb38b8 |
213 | DBM::Deep->_throw_error( "Cannot store something that is tied." ); |
d49782fe |
214 | } |
215 | if ( $r eq 'HASH' && tied(%$value) ) { |
25eb38b8 |
216 | DBM::Deep->_throw_error( "Cannot store something that is tied." ); |
d49782fe |
217 | } |
764e6cb9 |
218 | $class = 'DBM::Deep::Engine::Sector::Reference'; |
ed38e772 |
219 | $type = substr( $r, 0, 1 ); |
764e6cb9 |
220 | } |
68369f26 |
221 | else { |
4eee718c |
222 | $class = 'DBM::Deep::Engine::Sector::Scalar'; |
68369f26 |
223 | } |
3976d8c9 |
224 | |
2432d6cc |
225 | # This will be a Reference sector |
226 | my $sector = $self->_load_sector( $obj->_base_offset ) |
76c68c87 |
227 | or die "Cannot write to a deleted spot in DBM::Deep.\n"; |
ed38e772 |
228 | |
8af340bf |
229 | if ( $sector->staleness != $obj->_staleness ) { |
230 | die "Cannot write to a deleted spot in DBM::Deep.\n"; |
231 | } |
232 | |
2432d6cc |
233 | # Create this after loading the reference sector in case something bad happens. |
234 | # This way, we won't allocate value sector(s) needlessly. |
4eee718c |
235 | my $value_sector = $class->new({ |
236 | engine => $self, |
237 | data => $value, |
764e6cb9 |
238 | type => $type, |
4eee718c |
239 | }); |
240 | |
2432d6cc |
241 | $sector->write_data({ |
242 | key => $key, |
243 | key_md5 => $self->_apply_digest( $key ), |
244 | value => $value_sector, |
245 | }); |
764e6cb9 |
246 | |
247 | # This code is to make sure we write all the values in the $value to the disk |
ed38e772 |
248 | # and to make sure all changes to $value after the assignment are reflected |
249 | # on disk. This may be counter-intuitive at first, but it is correct dwimmery. |
250 | # NOTE - simply tying $value won't perform a STORE on each value. Hence, the |
251 | # copy to a temp value. |
764e6cb9 |
252 | if ( $r eq 'ARRAY' ) { |
ed38e772 |
253 | my @temp = @$value; |
764e6cb9 |
254 | tie @$value, 'DBM::Deep', { |
255 | base_offset => $value_sector->offset, |
8af340bf |
256 | staleness => $value_sector->staleness, |
764e6cb9 |
257 | storage => $self->storage, |
c9f02899 |
258 | engine => $self, |
764e6cb9 |
259 | }; |
ed38e772 |
260 | @$value = @temp; |
764e6cb9 |
261 | bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value ); |
262 | } |
263 | elsif ( $r eq 'HASH' ) { |
ed38e772 |
264 | my %temp = %$value; |
764e6cb9 |
265 | tie %$value, 'DBM::Deep', { |
266 | base_offset => $value_sector->offset, |
8af340bf |
267 | staleness => $value_sector->staleness, |
764e6cb9 |
268 | storage => $self->storage, |
c9f02899 |
269 | engine => $self, |
764e6cb9 |
270 | }; |
ed38e772 |
271 | |
272 | %$value = %temp; |
764e6cb9 |
273 | bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value ); |
274 | } |
275 | |
276 | return 1; |
696cadb7 |
277 | } |
278 | |
8af340bf |
279 | # XXX Add staleness here |
696cadb7 |
280 | sub get_next_key { |
281 | my $self = shift; |
c9f02899 |
282 | my ($obj, $prev_key) = @_; |
ed38e772 |
283 | |
284 | # XXX Need to add logic about resetting the iterator if any key in the reference has changed |
285 | unless ( $prev_key ) { |
0f4ed906 |
286 | $obj->{iterator} = DBM::Deep::Iterator->new({ |
c9f02899 |
287 | base_offset => $obj->_base_offset, |
ed38e772 |
288 | engine => $self, |
289 | }); |
4eee718c |
290 | } |
291 | |
8af340bf |
292 | return $obj->{iterator}->get_next_key( $obj ); |
696cadb7 |
293 | } |
294 | |
295 | ################################################################################ |
296 | |
297 | sub setup_fh { |
298 | my $self = shift; |
299 | my ($obj) = @_; |
300 | |
301 | # We're opening the file. |
302 | unless ( $obj->_base_offset ) { |
696cadb7 |
303 | my $bytes_read = $self->_read_file_header; |
696cadb7 |
304 | |
305 | # Creating a new file |
306 | unless ( $bytes_read ) { |
307 | $self->_write_file_header; |
c83524c6 |
308 | |
309 | # 1) Create Array/Hash entry |
8fbac729 |
310 | my $initial_reference = DBM::Deep::Engine::Sector::Reference->new({ |
311 | engine => $self, |
312 | type => $obj->_type, |
313 | }); |
314 | $obj->{base_offset} = $initial_reference->offset; |
8af340bf |
315 | $obj->{staleness} = $initial_reference->staleness; |
c83524c6 |
316 | |
8fbac729 |
317 | $self->storage->flush; |
696cadb7 |
318 | } |
319 | # Reading from an existing file |
320 | else { |
321 | $obj->{base_offset} = $bytes_read; |
764e6cb9 |
322 | my $initial_reference = DBM::Deep::Engine::Sector::Reference->new({ |
323 | engine => $self, |
324 | offset => $obj->_base_offset, |
325 | }); |
326 | unless ( $initial_reference ) { |
696cadb7 |
327 | DBM::Deep->_throw_error("Corrupted file, no master index record"); |
328 | } |
329 | |
764e6cb9 |
330 | unless ($obj->_type eq $initial_reference->type) { |
696cadb7 |
331 | DBM::Deep->_throw_error("File type mismatch"); |
332 | } |
8af340bf |
333 | |
334 | $obj->{staleness} = $initial_reference->staleness; |
696cadb7 |
335 | } |
336 | } |
696cadb7 |
337 | |
696cadb7 |
338 | return 1; |
339 | } |
340 | |
8cb9205a |
341 | sub begin_work { |
c9f02899 |
342 | my $self = shift; |
8cb9205a |
343 | my ($obj) = @_; |
344 | |
345 | if ( $self->trans_id ) { |
6f999f6e |
346 | DBM::Deep->_throw_error( "Cannot begin_work within a transaction" ); |
8cb9205a |
347 | } |
348 | |
cf03415a |
349 | my @slots = $self->read_txn_slots; |
8cb9205a |
350 | for my $i ( 1 .. @slots ) { |
351 | next if $slots[$i]; |
352 | $slots[$i] = 1; |
353 | $self->set_trans_id( $i ); |
354 | last; |
355 | } |
cf03415a |
356 | $self->write_txn_slots( @slots ); |
8cb9205a |
357 | |
358 | if ( !$self->trans_id ) { |
6f999f6e |
359 | DBM::Deep->_throw_error( "Cannot begin_work - no available transactions" ); |
8cb9205a |
360 | } |
361 | |
362 | return; |
c9f02899 |
363 | } |
696cadb7 |
364 | |
8cb9205a |
365 | sub rollback { |
696cadb7 |
366 | my $self = shift; |
8cb9205a |
367 | my ($obj) = @_; |
368 | |
369 | if ( !$self->trans_id ) { |
6f999f6e |
370 | DBM::Deep->_throw_error( "Cannot rollback without a transaction" ); |
371 | } |
372 | |
373 | # Each entry is the file location for a bucket that has a modification for |
374 | # this transaction. The entries need to be expunged. |
375 | foreach my $entry (@{ $self->get_entries } ) { |
376 | # Remove the entry here |
377 | my $read_loc = $entry |
378 | + $self->hash_size |
379 | + $self->byte_size |
17164f8a |
380 | + $self->trans_id * ( $self->byte_size + 4 ); |
6f999f6e |
381 | |
382 | my $data_loc = $self->storage->read_at( $read_loc, $self->byte_size ); |
383 | $data_loc = unpack( $StP{$self->byte_size}, $data_loc ); |
384 | $self->storage->print_at( $read_loc, pack( $StP{$self->byte_size}, 0 ) ); |
385 | |
386 | if ( $data_loc > 1 ) { |
387 | $self->_load_sector( $data_loc )->free; |
388 | } |
8cb9205a |
389 | } |
6f999f6e |
390 | |
391 | $self->clear_entries; |
392 | |
cf03415a |
393 | my @slots = $self->read_txn_slots; |
6f999f6e |
394 | $slots[$self->trans_id] = 0; |
cf03415a |
395 | $self->write_txn_slots( @slots ); |
6de4e4e9 |
396 | $self->inc_txn_staleness_counter( $self->trans_id ); |
6f999f6e |
397 | $self->set_trans_id( 0 ); |
398 | |
399 | return 1; |
c9f02899 |
400 | } |
696cadb7 |
401 | |
8cb9205a |
402 | sub commit { |
c9f02899 |
403 | my $self = shift; |
8cb9205a |
404 | my ($obj) = @_; |
405 | |
406 | if ( !$self->trans_id ) { |
6f999f6e |
407 | DBM::Deep->_throw_error( "Cannot commit without a transaction" ); |
408 | } |
409 | |
6f999f6e |
410 | foreach my $entry (@{ $self->get_entries } ) { |
6f999f6e |
411 | # Overwrite the entry in head with the entry in trans_id |
412 | my $base = $entry |
413 | + $self->hash_size |
414 | + $self->byte_size; |
415 | |
416 | my $head_loc = $self->storage->read_at( $base, $self->byte_size ); |
417 | $head_loc = unpack( $StP{$self->byte_size}, $head_loc ); |
418 | my $trans_loc = $self->storage->read_at( |
17164f8a |
419 | $base + $self->trans_id * ( $self->byte_size + 4 ), $self->byte_size, |
6f999f6e |
420 | ); |
421 | |
422 | $self->storage->print_at( $base, $trans_loc ); |
423 | $self->storage->print_at( |
17164f8a |
424 | $base + $self->trans_id * ( $self->byte_size + 4 ), |
6de4e4e9 |
425 | pack( $StP{$self->byte_size} . ' N', (0) x 2 ), |
6f999f6e |
426 | ); |
427 | |
428 | if ( $head_loc > 1 ) { |
429 | $self->_load_sector( $head_loc )->free; |
430 | } |
8cb9205a |
431 | } |
6f999f6e |
432 | |
433 | $self->clear_entries; |
434 | |
cf03415a |
435 | my @slots = $self->read_txn_slots; |
6f999f6e |
436 | $slots[$self->trans_id] = 0; |
cf03415a |
437 | $self->write_txn_slots( @slots ); |
6de4e4e9 |
438 | $self->inc_txn_staleness_counter( $self->trans_id ); |
6f999f6e |
439 | $self->set_trans_id( 0 ); |
440 | |
441 | return 1; |
8cb9205a |
442 | } |
443 | |
cf03415a |
444 | sub read_txn_slots { |
8cb9205a |
445 | my $self = shift; |
cf03415a |
446 | return split '', unpack( 'b32', |
447 | $self->storage->read_at( |
448 | $self->trans_loc, 4, |
449 | ) |
450 | ); |
8cb9205a |
451 | } |
452 | |
cf03415a |
453 | sub write_txn_slots { |
8cb9205a |
454 | my $self = shift; |
455 | $self->storage->print_at( $self->trans_loc, |
cf03415a |
456 | pack( 'b32', join('', @_) ), |
8cb9205a |
457 | ); |
c9f02899 |
458 | } |
696cadb7 |
459 | |
cf03415a |
460 | sub get_running_txn_ids { |
461 | my $self = shift; |
462 | my @transactions = $self->read_txn_slots; |
463 | my @trans_ids = grep { $transactions[$_] } 0 .. $#transactions; |
464 | } |
465 | |
6de4e4e9 |
466 | sub get_txn_staleness_counter { |
467 | my $self = shift; |
468 | my ($trans_id) = @_; |
b4e17919 |
469 | |
470 | # Hardcode staleness of 0 for the HEAD |
471 | return 0 unless $trans_id; |
472 | |
41e27db3 |
473 | my $x = unpack( 'N', |
6de4e4e9 |
474 | $self->storage->read_at( |
b4e17919 |
475 | $self->trans_loc + 4 * $trans_id, |
41e27db3 |
476 | 4, |
6de4e4e9 |
477 | ) |
478 | ); |
41e27db3 |
479 | return $x; |
6de4e4e9 |
480 | } |
481 | |
482 | sub inc_txn_staleness_counter { |
483 | my $self = shift; |
484 | my ($trans_id) = @_; |
b4e17919 |
485 | |
486 | # Hardcode staleness of 0 for the HEAD |
487 | return unless $trans_id; |
488 | |
6de4e4e9 |
489 | $self->storage->print_at( |
b4e17919 |
490 | $self->trans_loc + 4 * $trans_id, |
6de4e4e9 |
491 | pack( 'N', $self->get_txn_staleness_counter( $trans_id ) + 1 ), |
492 | ); |
493 | } |
494 | |
6f999f6e |
495 | sub get_entries { |
496 | my $self = shift; |
497 | return [ keys %{ $self->{entries}{$self->trans_id} ||= {} } ]; |
498 | } |
499 | |
500 | sub add_entry { |
501 | my $self = shift; |
502 | my ($trans_id, $loc) = @_; |
503 | |
6f999f6e |
504 | $self->{entries}{$trans_id} ||= {}; |
505 | $self->{entries}{$trans_id}{$loc} = undef; |
6f999f6e |
506 | } |
507 | |
65bd261b |
508 | # If the buckets are being relocated because of a reindexing, the entries |
509 | # mechanism needs to be made aware of it. |
510 | sub reindex_entry { |
511 | my $self = shift; |
512 | my ($old_loc, $new_loc) = @_; |
513 | |
514 | TRANS: |
515 | while ( my ($trans_id, $locs) = each %{ $self->{entries} } ) { |
516 | foreach my $orig_loc ( keys %{ $locs } ) { |
517 | if ( $orig_loc == $old_loc ) { |
518 | delete $locs->{orig_loc}; |
519 | $locs->{$new_loc} = undef; |
520 | next TRANS; |
521 | } |
522 | } |
523 | } |
524 | } |
525 | |
6f999f6e |
526 | sub clear_entries { |
527 | my $self = shift; |
6f999f6e |
528 | delete $self->{entries}{$self->trans_id}; |
529 | } |
530 | |
c9f02899 |
531 | ################################################################################ |
b9ec359f |
532 | |
c9f02899 |
533 | { |
534 | my $header_fixed = length( SIG_FILE ) + 1 + 4 + 4; |
696cadb7 |
535 | |
c9f02899 |
536 | sub _write_file_header { |
537 | my $self = shift; |
696cadb7 |
538 | |
d58fd793 |
539 | my $header_var = 1 + 1 + 4 + 4 * $self->num_txns + 3 * $self->byte_size; |
696cadb7 |
540 | |
c9f02899 |
541 | my $loc = $self->storage->request_space( $header_fixed + $header_var ); |
c83524c6 |
542 | |
c9f02899 |
543 | $self->storage->print_at( $loc, |
544 | SIG_FILE, |
545 | SIG_HEADER, |
546 | pack('N', 1), # header version - at this point, we're at 9 bytes |
547 | pack('N', $header_var), # header size |
548 | # --- Above is $header_fixed. Below is $header_var |
549 | pack('C', $self->byte_size), |
550 | pack('C', $self->max_buckets), |
b4e17919 |
551 | pack('N', 0 ), # Transaction activeness bitfield |
552 | pack('N' . $self->num_txns, 0 x $self->num_txns ), # Transaction staleness counters |
c9f02899 |
553 | pack($StP{$self->byte_size}, 0), # Start of free chain (blist size) |
554 | pack($StP{$self->byte_size}, 0), # Start of free chain (data size) |
d58fd793 |
555 | pack($StP{$self->byte_size}, 0), # Start of free chain (index size) |
c9f02899 |
556 | ); |
696cadb7 |
557 | |
c9f02899 |
558 | $self->set_trans_loc( $header_fixed + 2 ); |
cf03415a |
559 | $self->set_chains_loc( $header_fixed + 2 + 4 + 4 * $self->num_txns ); |
696cadb7 |
560 | |
c9f02899 |
561 | return; |
696cadb7 |
562 | } |
563 | |
c9f02899 |
564 | sub _read_file_header { |
565 | my $self = shift; |
696cadb7 |
566 | |
c9f02899 |
567 | my $buffer = $self->storage->read_at( 0, $header_fixed ); |
568 | return unless length($buffer); |
696cadb7 |
569 | |
c9f02899 |
570 | my ($file_signature, $sig_header, $header_version, $size) = unpack( |
571 | 'A4 A N N', $buffer |
572 | ); |
b9ec359f |
573 | |
c9f02899 |
574 | unless ( $file_signature eq SIG_FILE ) { |
575 | $self->storage->close; |
576 | DBM::Deep->_throw_error( "Signature not found -- file is not a Deep DB" ); |
577 | } |
696cadb7 |
578 | |
c9f02899 |
579 | unless ( $sig_header eq SIG_HEADER ) { |
580 | $self->storage->close; |
581 | DBM::Deep->_throw_error( "Old file version found." ); |
582 | } |
696cadb7 |
583 | |
c9f02899 |
584 | my $buffer2 = $self->storage->read_at( undef, $size ); |
585 | my @values = unpack( 'C C', $buffer2 ); |
696cadb7 |
586 | |
c9f02899 |
587 | $self->set_trans_loc( $header_fixed + 2 ); |
cf03415a |
588 | $self->set_chains_loc( $header_fixed + 2 + 4 + 4 * $self->num_txns ); |
c9f02899 |
589 | |
590 | if ( @values < 2 || grep { !defined } @values ) { |
591 | $self->storage->close; |
592 | DBM::Deep->_throw_error("Corrupted file - bad header"); |
593 | } |
594 | |
595 | #XXX Add warnings if values weren't set right |
596 | @{$self}{qw(byte_size max_buckets)} = @values; |
b9ec359f |
597 | |
d58fd793 |
598 | my $header_var = 1 + 1 + 4 + 4 * $self->num_txns + 3 * $self->byte_size; |
c9f02899 |
599 | unless ( $size eq $header_var ) { |
600 | $self->storage->close; |
601 | DBM::Deep->_throw_error( "Unexpected size found ($size <-> $header_var)." ); |
602 | } |
603 | |
604 | return length($buffer) + length($buffer2); |
605 | } |
696cadb7 |
606 | } |
607 | |
3976d8c9 |
608 | sub _load_sector { |
609 | my $self = shift; |
610 | my ($offset) = @_; |
611 | |
0f4ed906 |
612 | # Add a catch for offset of 0 or 1 |
613 | return if $offset <= 1; |
614 | |
3976d8c9 |
615 | my $type = $self->storage->read_at( $offset, 1 ); |
b9ec359f |
616 | return if $type eq chr(0); |
617 | |
3976d8c9 |
618 | if ( $type eq $self->SIG_ARRAY || $type eq $self->SIG_HASH ) { |
619 | return DBM::Deep::Engine::Sector::Reference->new({ |
620 | engine => $self, |
621 | type => $type, |
622 | offset => $offset, |
623 | }); |
624 | } |
2432d6cc |
625 | # XXX Don't we need key_md5 here? |
3976d8c9 |
626 | elsif ( $type eq $self->SIG_BLIST ) { |
627 | return DBM::Deep::Engine::Sector::BucketList->new({ |
628 | engine => $self, |
629 | type => $type, |
630 | offset => $offset, |
631 | }); |
632 | } |
d58fd793 |
633 | elsif ( $type eq $self->SIG_INDEX ) { |
634 | return DBM::Deep::Engine::Sector::Index->new({ |
635 | engine => $self, |
636 | type => $type, |
637 | offset => $offset, |
638 | }); |
639 | } |
68369f26 |
640 | elsif ( $type eq $self->SIG_NULL ) { |
641 | return DBM::Deep::Engine::Sector::Null->new({ |
642 | engine => $self, |
643 | type => $type, |
644 | offset => $offset, |
645 | }); |
646 | } |
647 | elsif ( $type eq $self->SIG_DATA ) { |
648 | return DBM::Deep::Engine::Sector::Scalar->new({ |
649 | engine => $self, |
650 | type => $type, |
651 | offset => $offset, |
652 | }); |
653 | } |
b9ec359f |
654 | # This was deleted from under us, so just return and let the caller figure it out. |
655 | elsif ( $type eq $self->SIG_FREE ) { |
656 | return; |
657 | } |
3976d8c9 |
658 | |
ed38e772 |
659 | die "'$offset': Don't know what to do with type '$type'\n"; |
3976d8c9 |
660 | } |
661 | |
662 | sub _apply_digest { |
663 | my $self = shift; |
664 | return $self->{digest}->(@_); |
665 | } |
666 | |
c0507636 |
667 | sub _add_free_blist_sector { shift->_add_free_sector( 0, @_ ) } |
668 | sub _add_free_data_sector { shift->_add_free_sector( 1, @_ ) } |
669 | sub _add_free_index_sector { shift->_add_free_sector( 2, @_ ) } |
670 | |
ed38e772 |
671 | sub _add_free_sector { |
672 | my $self = shift; |
c0507636 |
673 | my ($multiple, $offset, $size) = @_; |
b9ec359f |
674 | |
c0507636 |
675 | my $chains_offset = $multiple * $self->byte_size; |
b9ec359f |
676 | |
8af340bf |
677 | my $storage = $self->storage; |
678 | |
679 | # Increment staleness. |
c0507636 |
680 | # XXX Can this increment+modulo be done by "&= 0x1" ? |
d58fd793 |
681 | my $staleness = unpack( $StP{STALE_SIZE()}, $storage->read_at( $offset + SIG_SIZE, STALE_SIZE ) ); |
682 | $staleness = ($staleness + 1 ) % ( 2 ** ( 8 * STALE_SIZE ) ); |
683 | $storage->print_at( $offset + SIG_SIZE, pack( $StP{STALE_SIZE()}, $staleness ) ); |
b9ec359f |
684 | |
8af340bf |
685 | my $old_head = $storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
686 | |
687 | $storage->print_at( $self->chains_loc + $chains_offset, |
b9ec359f |
688 | pack( $StP{$self->byte_size}, $offset ), |
689 | ); |
690 | |
8af340bf |
691 | # Record the old head in the new sector after the signature and staleness counter |
d58fd793 |
692 | $storage->print_at( $offset + SIG_SIZE + STALE_SIZE, $old_head ); |
b9ec359f |
693 | } |
694 | |
c0507636 |
695 | sub _request_blist_sector { shift->_request_sector( 0, @_ ) } |
696 | sub _request_data_sector { shift->_request_sector( 1, @_ ) } |
697 | sub _request_index_sector { shift->_request_sector( 2, @_ ) } |
698 | |
b9ec359f |
699 | sub _request_sector { |
700 | my $self = shift; |
c0507636 |
701 | my ($multiple, $size) = @_; |
b9ec359f |
702 | |
c0507636 |
703 | my $chains_offset = $multiple * $self->byte_size; |
b9ec359f |
704 | |
705 | my $old_head = $self->storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
706 | my $loc = unpack( $StP{$self->byte_size}, $old_head ); |
707 | |
708 | # We don't have any free sectors of the right size, so allocate a new one. |
709 | unless ( $loc ) { |
8af340bf |
710 | my $offset = $self->storage->request_space( $size ); |
711 | |
712 | # Zero out the new sector. This also guarantees correct increases |
713 | # in the filesize. |
714 | $self->storage->print_at( $offset, chr(0) x $size ); |
715 | |
716 | return $offset; |
b9ec359f |
717 | } |
718 | |
8af340bf |
719 | # Read the new head after the signature and the staleness counter |
d58fd793 |
720 | my $new_head = $self->storage->read_at( $loc + SIG_SIZE + STALE_SIZE, $self->byte_size ); |
b9ec359f |
721 | $self->storage->print_at( $self->chains_loc + $chains_offset, $new_head ); |
722 | |
723 | return $loc; |
ed38e772 |
724 | } |
725 | |
696cadb7 |
726 | ################################################################################ |
727 | |
3976d8c9 |
728 | sub storage { $_[0]{storage} } |
729 | sub byte_size { $_[0]{byte_size} } |
730 | sub hash_size { $_[0]{hash_size} } |
6a4f323c |
731 | sub hash_chars { $_[0]{hash_chars} } |
3976d8c9 |
732 | sub num_txns { $_[0]{num_txns} } |
733 | sub max_buckets { $_[0]{max_buckets} } |
c000ae6e |
734 | sub blank_md5 { chr(0) x $_[0]->hash_size } |
8fbac729 |
735 | |
8cb9205a |
736 | sub trans_id { $_[0]{trans_id} } |
737 | sub set_trans_id { $_[0]{trans_id} = $_[1] } |
738 | |
c9f02899 |
739 | sub trans_loc { $_[0]{trans_loc} } |
740 | sub set_trans_loc { $_[0]{trans_loc} = $_[1] } |
741 | |
b9ec359f |
742 | sub chains_loc { $_[0]{chains_loc} } |
743 | sub set_chains_loc { $_[0]{chains_loc} = $_[1] } |
744 | |
8fbac729 |
745 | ################################################################################ |
746 | |
0f4ed906 |
747 | package DBM::Deep::Iterator; |
ed38e772 |
748 | |
749 | sub new { |
750 | my $class = shift; |
751 | my ($args) = @_; |
752 | |
753 | my $self = bless { |
754 | breadcrumbs => [], |
755 | engine => $args->{engine}, |
756 | base_offset => $args->{base_offset}, |
ed38e772 |
757 | }, $class; |
758 | |
759 | Scalar::Util::weaken( $self->{engine} ); |
760 | |
761 | return $self; |
762 | } |
763 | |
0f4ed906 |
764 | sub reset { $_[0]{breadcrumbs} = [] } |
765 | |
766 | sub get_sector_iterator { |
ed38e772 |
767 | my $self = shift; |
0f4ed906 |
768 | my ($loc) = @_; |
769 | |
770 | my $sector = $self->{engine}->_load_sector( $loc ) |
771 | or return; |
772 | |
773 | if ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
774 | return DBM::Deep::Iterator::Index->new({ |
775 | iterator => $self, |
776 | sector => $sector, |
777 | }); |
778 | } |
779 | elsif ( $sector->isa( 'DBM::Deep::Engine::Sector::BucketList' ) ) { |
780 | return DBM::Deep::Iterator::BucketList->new({ |
781 | iterator => $self, |
782 | sector => $sector, |
783 | }); |
784 | } |
785 | else { |
786 | die "Why did $loc make a $sector?"; |
787 | } |
ed38e772 |
788 | } |
789 | |
790 | sub get_next_key { |
791 | my $self = shift; |
8af340bf |
792 | my ($obj) = @_; |
ed38e772 |
793 | |
794 | my $crumbs = $self->{breadcrumbs}; |
0f4ed906 |
795 | my $e = $self->{engine}; |
ed38e772 |
796 | |
797 | unless ( @$crumbs ) { |
798 | # This will be a Reference sector |
0f4ed906 |
799 | my $sector = $e->_load_sector( $self->{base_offset} ) |
b9ec359f |
800 | # If no sector is found, thist must have been deleted from under us. |
801 | or return; |
8af340bf |
802 | |
803 | if ( $sector->staleness != $obj->_staleness ) { |
804 | return; |
805 | } |
806 | |
0f4ed906 |
807 | my $loc = $sector->get_blist_loc |
808 | or return; |
809 | |
810 | push @$crumbs, $self->get_sector_iterator( $loc ); |
ed38e772 |
811 | } |
812 | |
0f4ed906 |
813 | FIND_NEXT_KEY: { |
814 | # We're at the end. |
815 | unless ( @$crumbs ) { |
ed38e772 |
816 | $self->reset; |
0f4ed906 |
817 | return; |
ed38e772 |
818 | } |
819 | |
0f4ed906 |
820 | my $iterator = $crumbs->[-1]; |
821 | |
822 | # This level is done. |
823 | if ( $iterator->at_end ) { |
824 | pop @$crumbs; |
825 | redo FIND_NEXT_KEY; |
2432d6cc |
826 | } |
827 | |
0f4ed906 |
828 | if ( $iterator->isa( 'DBM::Deep::Iterator::Index' ) ) { |
829 | # If we don't have any more, it will be caught at the |
830 | # prior check. |
831 | if ( my $next = $iterator->get_next_iterator ) { |
832 | push @$crumbs, $next; |
833 | } |
834 | redo FIND_NEXT_KEY; |
835 | } |
ed38e772 |
836 | |
0f4ed906 |
837 | unless ( $iterator->isa( 'DBM::Deep::Iterator::BucketList' ) ) { |
838 | DBM::Deep->_throw_error( |
839 | "Should have a bucketlist iterator here - instead have $iterator" |
840 | ); |
2432d6cc |
841 | } |
842 | |
0f4ed906 |
843 | # At this point, we have a BucketList iterator |
844 | my $key = $iterator->get_next_key; |
845 | if ( defined $key ) { |
846 | return $key; |
ed38e772 |
847 | } |
848 | |
0f4ed906 |
849 | # We hit the end of the bucketlist iterator, so redo |
850 | redo FIND_NEXT_KEY; |
851 | } |
852 | |
853 | DBM::Deep->_throw_error( "get_next_key(): How did we get here?" ); |
854 | } |
855 | |
856 | package DBM::Deep::Iterator::Index; |
857 | |
858 | sub new { |
859 | my $self = bless $_[1] => $_[0]; |
860 | $self->{curr_index} = 0; |
861 | return $self; |
862 | } |
863 | |
864 | sub at_end { |
865 | my $self = shift; |
866 | return $self->{curr_index} >= $self->{iterator}{engine}->hash_chars; |
867 | } |
868 | |
869 | sub get_next_iterator { |
870 | my $self = shift; |
871 | |
872 | my $loc; |
873 | while ( !$loc ) { |
874 | return if $self->at_end; |
875 | $loc = $self->{sector}->get_entry( $self->{curr_index}++ ); |
ed38e772 |
876 | } |
877 | |
0f4ed906 |
878 | return $self->{iterator}->get_sector_iterator( $loc ); |
879 | } |
880 | |
881 | package DBM::Deep::Iterator::BucketList; |
882 | |
883 | sub new { |
884 | my $self = bless $_[1] => $_[0]; |
885 | $self->{curr_index} = 0; |
886 | return $self; |
887 | } |
888 | |
889 | sub at_end { |
890 | my $self = shift; |
891 | return $self->{curr_index} >= $self->{iterator}{engine}->max_buckets; |
892 | } |
893 | |
894 | sub get_next_key { |
895 | my $self = shift; |
896 | |
897 | return if $self->at_end; |
898 | |
9ce79856 |
899 | my $data_loc = $self->{sector}->get_data_location_for({ |
900 | allow_head => 1, |
901 | idx => $self->{curr_index}++, |
902 | }) or return; |
903 | |
904 | my $key_sector = $self->{sector}->get_key_for( $self->{curr_index} - 1 ); |
905 | |
906 | #XXX Is this check necessary now? |
0f4ed906 |
907 | return unless $key_sector; |
908 | |
909 | return $key_sector->data; |
ed38e772 |
910 | } |
911 | |
3976d8c9 |
912 | package DBM::Deep::Engine::Sector; |
913 | |
914 | sub new { |
915 | my $self = bless $_[1], $_[0]; |
916 | Scalar::Util::weaken( $self->{engine} ); |
917 | $self->_init; |
918 | return $self; |
919 | } |
920 | sub _init {} |
2432d6cc |
921 | sub clone { die "Must be implemented in the child class" } |
3976d8c9 |
922 | |
923 | sub engine { $_[0]{engine} } |
924 | sub offset { $_[0]{offset} } |
925 | sub type { $_[0]{type} } |
926 | |
d58fd793 |
927 | sub base_size { |
928 | my $self = shift; |
929 | return $self->engine->SIG_SIZE + $self->engine->STALE_SIZE; |
930 | } |
b6fc126b |
931 | |
ed38e772 |
932 | sub free { |
933 | my $self = shift; |
934 | |
b6fc126b |
935 | my $e = $self->engine; |
936 | |
937 | $e->storage->print_at( $self->offset, $e->SIG_FREE ); |
8af340bf |
938 | # Skip staleness counter |
b6fc126b |
939 | $e->storage->print_at( $self->offset + $self->base_size, |
940 | chr(0) x ($self->size - $self->base_size), |
b9ec359f |
941 | ); |
942 | |
c0507636 |
943 | my $free_meth = $self->free_meth; |
944 | $e->$free_meth( $self->offset, $self->size ); |
ed38e772 |
945 | |
b9ec359f |
946 | return; |
ed38e772 |
947 | } |
3976d8c9 |
948 | |
949 | package DBM::Deep::Engine::Sector::Data; |
8fbac729 |
950 | |
951 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
952 | |
3976d8c9 |
953 | # This is in bytes |
954 | sub size { return 256 } |
c0507636 |
955 | sub free_meth { return '_add_free_data_sector' } |
3976d8c9 |
956 | |
2432d6cc |
957 | sub clone { |
958 | my $self = shift; |
959 | return ref($self)->new({ |
960 | engine => $self->engine, |
961 | data => $self->data, |
962 | type => $self->type, |
963 | }); |
964 | } |
965 | |
3976d8c9 |
966 | package DBM::Deep::Engine::Sector::Scalar; |
967 | |
968 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
969 | |
ad4ae302 |
970 | sub free { |
971 | my $self = shift; |
972 | |
973 | my $chain_loc = $self->chain_loc; |
974 | |
975 | $self->SUPER::free(); |
976 | |
977 | if ( $chain_loc ) { |
978 | $self->engine->_load_sector( $chain_loc )->free; |
979 | } |
980 | |
981 | return; |
982 | } |
983 | |
3976d8c9 |
984 | sub type { $_[0]{engine}->SIG_DATA } |
8fbac729 |
985 | sub _init { |
986 | my $self = shift; |
987 | |
988 | my $engine = $self->engine; |
989 | |
3976d8c9 |
990 | unless ( $self->offset ) { |
b6fc126b |
991 | my $data_section = $self->size - $self->base_size - 1 * $engine->byte_size - 1; |
3976d8c9 |
992 | |
c0507636 |
993 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
ad4ae302 |
994 | |
2432d6cc |
995 | my $data = delete $self->{data}; |
ad4ae302 |
996 | my $dlen = length $data; |
997 | my $continue = 1; |
998 | my $curr_offset = $self->offset; |
999 | while ( $continue ) { |
1000 | |
1001 | my $next_offset = 0; |
1002 | |
1003 | my ($leftover, $this_len, $chunk); |
1004 | if ( $dlen > $data_section ) { |
1005 | $leftover = 0; |
1006 | $this_len = $data_section; |
1007 | $chunk = substr( $data, 0, $this_len ); |
1008 | |
1009 | $dlen -= $data_section; |
c0507636 |
1010 | $next_offset = $engine->_request_data_sector( $self->size ); |
ad4ae302 |
1011 | $data = substr( $data, $this_len ); |
1012 | } |
1013 | else { |
1014 | $leftover = $data_section - $dlen; |
1015 | $this_len = $dlen; |
1016 | $chunk = $data; |
1017 | |
1018 | $continue = 0; |
1019 | } |
1020 | |
8af340bf |
1021 | $engine->storage->print_at( $curr_offset, $self->type ); # Sector type |
1022 | # Skip staleness |
d58fd793 |
1023 | $engine->storage->print_at( $curr_offset + $self->base_size, |
ad4ae302 |
1024 | pack( $StP{$engine->byte_size}, $next_offset ), # Chain loc |
1025 | pack( $StP{1}, $this_len ), # Data length |
1026 | $chunk, # Data to be stored in this sector |
1027 | chr(0) x $leftover, # Zero-fill the rest |
1028 | ); |
1029 | |
1030 | $curr_offset = $next_offset; |
1031 | } |
3976d8c9 |
1032 | |
1033 | return; |
1034 | } |
1035 | } |
1036 | |
1037 | sub data_length { |
1038 | my $self = shift; |
1039 | |
ad4ae302 |
1040 | my $buffer = $self->engine->storage->read_at( |
b6fc126b |
1041 | $self->offset + $self->base_size + $self->engine->byte_size, 1 |
8fbac729 |
1042 | ); |
ad4ae302 |
1043 | |
1044 | return unpack( $StP{1}, $buffer ); |
1045 | } |
1046 | |
1047 | sub chain_loc { |
1048 | my $self = shift; |
1049 | my $chain_loc = $self->engine->storage->read_at( |
b6fc126b |
1050 | $self->offset + $self->base_size, $self->engine->byte_size, |
ad4ae302 |
1051 | ); |
1052 | return unpack( $StP{$self->engine->byte_size}, $chain_loc ); |
3976d8c9 |
1053 | } |
1054 | |
1055 | sub data { |
1056 | my $self = shift; |
8fbac729 |
1057 | |
378b4748 |
1058 | my $data; |
1059 | while ( 1 ) { |
1060 | my $chain_loc = $self->chain_loc; |
ad4ae302 |
1061 | |
378b4748 |
1062 | $data .= $self->engine->storage->read_at( |
b6fc126b |
1063 | $self->offset + $self->base_size + $self->engine->byte_size + 1, $self->data_length, |
378b4748 |
1064 | ); |
ad4ae302 |
1065 | |
378b4748 |
1066 | last unless $chain_loc; |
1067 | |
1068 | $self = $self->engine->_load_sector( $chain_loc ); |
ad4ae302 |
1069 | } |
1070 | |
1071 | return $data; |
8fbac729 |
1072 | } |
1073 | |
68369f26 |
1074 | package DBM::Deep::Engine::Sector::Null; |
1075 | |
1076 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
1077 | |
1078 | sub type { $_[0]{engine}->SIG_NULL } |
1079 | sub data_length { 0 } |
1080 | sub data { return } |
1081 | |
1082 | sub _init { |
1083 | my $self = shift; |
1084 | |
1085 | my $engine = $self->engine; |
1086 | |
1087 | unless ( $self->offset ) { |
b6fc126b |
1088 | my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1; |
68369f26 |
1089 | |
c0507636 |
1090 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
8af340bf |
1091 | $engine->storage->print_at( $self->offset, $self->type ); # Sector type |
1092 | # Skip staleness counter |
b6fc126b |
1093 | $engine->storage->print_at( $self->offset + $self->base_size, |
68369f26 |
1094 | pack( $StP{$engine->byte_size}, 0 ), # Chain loc |
1095 | pack( $StP{1}, $self->data_length ), # Data length |
1096 | chr(0) x $leftover, # Zero-fill the rest |
1097 | ); |
1098 | |
1099 | return; |
1100 | } |
1101 | } |
1102 | |
3976d8c9 |
1103 | package DBM::Deep::Engine::Sector::Reference; |
8fbac729 |
1104 | |
3976d8c9 |
1105 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
1106 | |
1107 | sub _init { |
1108 | my $self = shift; |
1109 | |
d58fd793 |
1110 | my $e = $self->engine; |
3976d8c9 |
1111 | |
1112 | unless ( $self->offset ) { |
ba075714 |
1113 | my $classname = Scalar::Util::blessed( delete $self->{data} ); |
d58fd793 |
1114 | my $leftover = $self->size - $self->base_size - 2 * $e->byte_size; |
d4f34951 |
1115 | |
1116 | my $class_offset = 0; |
1117 | if ( defined $classname ) { |
1118 | my $class_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
d58fd793 |
1119 | engine => $e, |
d4f34951 |
1120 | data => $classname, |
1121 | }); |
1122 | $class_offset = $class_sector->offset; |
1123 | } |
3976d8c9 |
1124 | |
c0507636 |
1125 | $self->{offset} = $e->_request_data_sector( $self->size ); |
d58fd793 |
1126 | $e->storage->print_at( $self->offset, $self->type ); # Sector type |
8af340bf |
1127 | # Skip staleness counter |
d58fd793 |
1128 | $e->storage->print_at( $self->offset + $self->base_size, |
1129 | pack( $StP{$e->byte_size}, 0 ), # Index/BList loc |
1130 | pack( $StP{$e->byte_size}, $class_offset ), # Classname loc |
c0507636 |
1131 | chr(0) x $leftover, # Zero-fill the rest |
3976d8c9 |
1132 | ); |
8af340bf |
1133 | } |
1134 | else { |
d58fd793 |
1135 | $self->{type} = $e->storage->read_at( $self->offset, 1 ); |
3976d8c9 |
1136 | } |
764e6cb9 |
1137 | |
8af340bf |
1138 | $self->{staleness} = unpack( |
d58fd793 |
1139 | $StP{$e->STALE_SIZE}, |
1140 | $e->storage->read_at( $self->offset + $e->SIG_SIZE, $e->STALE_SIZE ), |
8af340bf |
1141 | ); |
764e6cb9 |
1142 | |
1143 | return; |
3976d8c9 |
1144 | } |
1145 | |
d938be6a |
1146 | sub free { |
1147 | my $self = shift; |
1148 | |
1149 | my $blist_loc = $self->get_blist_loc; |
1150 | $self->engine->_load_sector( $blist_loc )->free if $blist_loc; |
1151 | |
1152 | my $class_loc = $self->get_class_offset; |
1153 | $self->engine->_load_sector( $class_loc )->free if $class_loc; |
1154 | |
1155 | $self->SUPER::free(); |
1156 | } |
1157 | |
8af340bf |
1158 | sub staleness { $_[0]{staleness} } |
1159 | |
2432d6cc |
1160 | sub get_data_for { |
1161 | my $self = shift; |
1162 | my ($args) = @_; |
1163 | |
1164 | # Assume that the head is not allowed unless otherwise specified. |
1165 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
1166 | |
1167 | # Assume we don't create a new blist location unless otherwise specified. |
1168 | $args->{create} = 0 unless exists $args->{create}; |
1169 | |
1170 | my $blist = $self->get_bucket_list({ |
1171 | key_md5 => $args->{key_md5}, |
0f4ed906 |
1172 | key => $args->{key}, |
2432d6cc |
1173 | create => $args->{create}, |
1174 | }); |
1175 | return unless $blist && $blist->{found}; |
1176 | |
1177 | # At this point, $blist knows where the md5 is. What it -doesn't- know yet |
1178 | # is whether or not this transaction has this key. That's part of the next |
1179 | # function call. |
1180 | my $location = $blist->get_data_location_for({ |
1181 | allow_head => $args->{allow_head}, |
1182 | }) or return; |
1183 | |
1184 | return $self->engine->_load_sector( $location ); |
1185 | } |
1186 | |
1187 | sub write_data { |
1188 | my $self = shift; |
1189 | my ($args) = @_; |
1190 | |
1191 | my $blist = $self->get_bucket_list({ |
1192 | key_md5 => $args->{key_md5}, |
0f4ed906 |
1193 | key => $args->{key}, |
2432d6cc |
1194 | create => 1, |
6f999f6e |
1195 | }) or die "How did write_data fail (no blist)?!\n"; |
2432d6cc |
1196 | |
1197 | # Handle any transactional bookkeeping. |
1198 | if ( $self->engine->trans_id ) { |
d938be6a |
1199 | if ( ! $blist->has_md5 ) { |
2432d6cc |
1200 | $blist->mark_deleted({ |
1201 | trans_id => 0, |
1202 | }); |
1203 | } |
1204 | } |
1205 | else { |
cf03415a |
1206 | my @trans_ids = $self->engine->get_running_txn_ids; |
d938be6a |
1207 | if ( $blist->has_md5 ) { |
2432d6cc |
1208 | if ( @trans_ids ) { |
1209 | my $old_value = $blist->get_data_for; |
1210 | foreach my $other_trans_id ( @trans_ids ) { |
b4e17919 |
1211 | next if $blist->get_data_location_for({ |
1212 | trans_id => $other_trans_id, |
1213 | allow_head => 0, |
1214 | }); |
2432d6cc |
1215 | $blist->write_md5({ |
1216 | trans_id => $other_trans_id, |
1217 | key => $args->{key}, |
1218 | key_md5 => $args->{key_md5}, |
1219 | value => $old_value->clone, |
1220 | }); |
1221 | } |
1222 | } |
1223 | } |
1224 | else { |
1225 | if ( @trans_ids ) { |
1226 | foreach my $other_trans_id ( @trans_ids ) { |
1227 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1228 | $blist->mark_deleted({ |
1229 | trans_id => $other_trans_id, |
1230 | }); |
1231 | } |
1232 | } |
1233 | } |
1234 | } |
1235 | |
6f999f6e |
1236 | #XXX Is this safe to do transactionally? |
2432d6cc |
1237 | # Free the place we're about to write to. |
1238 | if ( $blist->get_data_location_for({ allow_head => 0 }) ) { |
1239 | $blist->get_data_for({ allow_head => 0 })->free; |
1240 | } |
1241 | |
1242 | $blist->write_md5({ |
1243 | key => $args->{key}, |
1244 | key_md5 => $args->{key_md5}, |
1245 | value => $args->{value}, |
1246 | }); |
1247 | } |
1248 | |
1249 | sub delete_key { |
1250 | my $self = shift; |
1251 | my ($args) = @_; |
1252 | |
1253 | # XXX What should happen if this fails? |
1254 | my $blist = $self->get_bucket_list({ |
1255 | key_md5 => $args->{key_md5}, |
1256 | }) or die "How did delete_key fail (no blist)?!\n"; |
1257 | |
6f999f6e |
1258 | # Save the location so that we can free the data |
1259 | my $location = $blist->get_data_location_for({ |
1260 | allow_head => 0, |
1261 | }); |
26897a1c |
1262 | my $old_value = $location && $self->engine->_load_sector( $location ); |
6f999f6e |
1263 | |
1264 | if ( $self->engine->trans_id == 0 ) { |
cf03415a |
1265 | my @trans_ids = $self->engine->get_running_txn_ids; |
6f999f6e |
1266 | if ( @trans_ids ) { |
1267 | foreach my $other_trans_id ( @trans_ids ) { |
1268 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1269 | $blist->write_md5({ |
1270 | trans_id => $other_trans_id, |
1271 | key => $args->{key}, |
1272 | key_md5 => $args->{key_md5}, |
1273 | value => $old_value->clone, |
1274 | }); |
1275 | } |
1276 | } |
1277 | } |
1278 | |
1279 | $blist->mark_deleted( $args ); |
1280 | |
26897a1c |
1281 | my $data; |
1282 | if ( $old_value ) { |
1283 | $data = $old_value->data; |
1284 | $old_value->free; |
1285 | } |
6f999f6e |
1286 | |
1287 | return $data; |
2432d6cc |
1288 | } |
1289 | |
3976d8c9 |
1290 | sub get_blist_loc { |
1291 | my $self = shift; |
1292 | |
2432d6cc |
1293 | my $e = $self->engine; |
b6fc126b |
1294 | my $blist_loc = $e->storage->read_at( $self->offset + $self->base_size, $e->byte_size ); |
2432d6cc |
1295 | return unpack( $StP{$e->byte_size}, $blist_loc ); |
3976d8c9 |
1296 | } |
1297 | |
1298 | sub get_bucket_list { |
1299 | my $self = shift; |
1300 | my ($args) = @_; |
4eee718c |
1301 | $args ||= {}; |
3976d8c9 |
1302 | |
1303 | # XXX Add in check here for recycling? |
1304 | |
1305 | my $engine = $self->engine; |
1306 | |
1307 | my $blist_loc = $self->get_blist_loc; |
1308 | |
1309 | # There's no index or blist yet |
1310 | unless ( $blist_loc ) { |
1311 | return unless $args->{create}; |
1312 | |
1313 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
2432d6cc |
1314 | engine => $engine, |
1315 | key_md5 => $args->{key_md5}, |
3976d8c9 |
1316 | }); |
2432d6cc |
1317 | |
b6fc126b |
1318 | $engine->storage->print_at( $self->offset + $self->base_size, |
3976d8c9 |
1319 | pack( $StP{$engine->byte_size}, $blist->offset ), |
1320 | ); |
2432d6cc |
1321 | |
3976d8c9 |
1322 | return $blist; |
1323 | } |
1324 | |
d938be6a |
1325 | # Add searching here through the index layers, if any |
1326 | my $sector = $engine->_load_sector( $blist_loc ) |
1327 | or die "Cannot read sector at $blist_loc in get_bucket_list()"; |
1328 | my $i = 0; |
1329 | my $last_sector = undef; |
1330 | while ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
6a4f323c |
1331 | $blist_loc = $sector->get_entry( ord( substr( $args->{key_md5}, $i++, 1 ) ) ); |
d938be6a |
1332 | $last_sector = $sector; |
625a24b4 |
1333 | if ( $blist_loc ) { |
1334 | $sector = $engine->_load_sector( $blist_loc ) |
1335 | or die "Cannot read sector at $blist_loc in get_bucket_list()"; |
1336 | } |
1337 | else { |
1338 | $sector = undef; |
1339 | last; |
1340 | } |
1341 | } |
1342 | |
1343 | # This means we went through the Index sector(s) and found an empty slot |
1344 | unless ( $sector ) { |
1345 | return unless $args->{create}; |
1346 | |
1347 | die "No last_sector when attempting to build a new entry" |
1348 | unless $last_sector; |
1349 | |
1350 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
1351 | engine => $engine, |
1352 | key_md5 => $args->{key_md5}, |
1353 | }); |
1354 | |
1355 | $last_sector->set_entry( ord( substr( $args->{key_md5}, $i - 1, 1 ) ) => $blist->offset ); |
1356 | |
1357 | return $blist; |
d938be6a |
1358 | } |
1359 | |
1360 | $sector->find_md5( $args->{key_md5} ); |
1361 | |
1362 | # See whether or not we need to reindex the bucketlist |
6a4f323c |
1363 | if ( !$sector->has_md5 && $args->{create} && $sector->{idx} == -1 ) { |
6a4f323c |
1364 | my $new_index = DBM::Deep::Engine::Sector::Index->new({ |
1365 | engine => $engine, |
1366 | }); |
1367 | |
1368 | my %blist_cache; |
65bd261b |
1369 | #XXX q.v. the comments for this function. |
1370 | foreach my $entry ( $sector->chopped_up ) { |
1371 | my ($spot, $md5) = @{$entry}; |
6a4f323c |
1372 | my $idx = ord( substr( $md5, $i, 1 ) ); |
1373 | |
0f4ed906 |
1374 | # XXX This is inefficient |
6a4f323c |
1375 | my $blist = $blist_cache{$idx} |
1376 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1377 | engine => $engine, |
1378 | }); |
1379 | |
1380 | $new_index->set_entry( $idx => $blist->offset ); |
1381 | |
65bd261b |
1382 | my $new_spot = $blist->write_at_next_open( $md5 ); |
1383 | $engine->reindex_entry( $spot => $new_spot ); |
6a4f323c |
1384 | } |
1385 | |
0f4ed906 |
1386 | # Handle the new item separately. |
1387 | { |
1388 | my $idx = ord( substr( $args->{key_md5}, $i, 1 ) ); |
1389 | my $blist = $blist_cache{$idx} |
1390 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1391 | engine => $engine, |
1392 | }); |
1393 | |
1394 | $new_index->set_entry( $idx => $blist->offset ); |
1395 | |
1396 | #XXX THIS IS HACKY! |
1397 | $blist->find_md5( $args->{key_md5} ); |
1398 | $blist->write_md5({ |
1399 | key => $args->{key}, |
1400 | key_md5 => $args->{key_md5}, |
1401 | value => DBM::Deep::Engine::Sector::Null->new({ |
1402 | engine => $engine, |
1403 | data => undef, |
1404 | }), |
1405 | }); |
1406 | } |
1407 | |
6a4f323c |
1408 | if ( $last_sector ) { |
1409 | $last_sector->set_entry( |
1410 | ord( substr( $args->{key_md5}, $i - 1, 1 ) ), |
1411 | $new_index->offset, |
1412 | ); |
1413 | } else { |
1414 | $engine->storage->print_at( $self->offset + $self->base_size, |
1415 | pack( $StP{$engine->byte_size}, $new_index->offset ), |
1416 | ); |
1417 | } |
1418 | |
1419 | $sector->free; |
1420 | |
1421 | $sector = $blist_cache{ ord( substr( $args->{key_md5}, $i, 1 ) ) }; |
1422 | $sector->find_md5( $args->{key_md5} ); |
d938be6a |
1423 | } |
1424 | |
1425 | return $sector; |
3976d8c9 |
1426 | } |
1427 | |
d938be6a |
1428 | sub get_class_offset { |
ba075714 |
1429 | my $self = shift; |
1430 | |
d938be6a |
1431 | my $e = $self->engine; |
1432 | return unpack( |
1433 | $StP{$e->byte_size}, |
1434 | $e->storage->read_at( |
1435 | $self->offset + $self->base_size + 1 * $e->byte_size, $e->byte_size, |
1436 | ), |
ba075714 |
1437 | ); |
d938be6a |
1438 | } |
1439 | |
1440 | sub get_classname { |
1441 | my $self = shift; |
1442 | |
1443 | my $class_offset = $self->get_class_offset; |
ba075714 |
1444 | |
d4f34951 |
1445 | return unless $class_offset; |
ba075714 |
1446 | |
d4f34951 |
1447 | return $self->engine->_load_sector( $class_offset )->data; |
ba075714 |
1448 | } |
1449 | |
764e6cb9 |
1450 | sub data { |
1451 | my $self = shift; |
1452 | |
1453 | my $new_obj = DBM::Deep->new({ |
1454 | type => $self->type, |
1455 | base_offset => $self->offset, |
8af340bf |
1456 | staleness => $self->staleness, |
764e6cb9 |
1457 | storage => $self->engine->storage, |
c9f02899 |
1458 | engine => $self->engine, |
764e6cb9 |
1459 | }); |
1460 | |
ba075714 |
1461 | if ( $self->engine->storage->{autobless} ) { |
1462 | my $classname = $self->get_classname; |
1463 | if ( defined $classname ) { |
1464 | bless $new_obj, $classname; |
1465 | } |
1466 | } |
1467 | |
764e6cb9 |
1468 | return $new_obj; |
1469 | } |
1470 | |
3976d8c9 |
1471 | package DBM::Deep::Engine::Sector::BucketList; |
1472 | |
1473 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1474 | |
1475 | sub _init { |
1476 | my $self = shift; |
1477 | |
1478 | my $engine = $self->engine; |
1479 | |
1480 | unless ( $self->offset ) { |
c000ae6e |
1481 | my $leftover = $self->size - $self->base_size; |
3976d8c9 |
1482 | |
c0507636 |
1483 | $self->{offset} = $engine->_request_blist_sector( $self->size ); |
8af340bf |
1484 | $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type |
1485 | # Skip staleness counter |
b6fc126b |
1486 | $engine->storage->print_at( $self->offset + $self->base_size, |
3976d8c9 |
1487 | chr(0) x $leftover, # Zero-fill the data |
1488 | ); |
1489 | } |
8fbac729 |
1490 | |
2432d6cc |
1491 | if ( $self->{key_md5} ) { |
1492 | $self->find_md5; |
1493 | } |
1494 | |
8fbac729 |
1495 | return $self; |
1496 | } |
8fbac729 |
1497 | |
3976d8c9 |
1498 | sub size { |
1499 | my $self = shift; |
2432d6cc |
1500 | unless ( $self->{size} ) { |
1501 | my $e = $self->engine; |
d938be6a |
1502 | # Base + numbuckets * bucketsize |
1503 | $self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size; |
2432d6cc |
1504 | } |
1505 | return $self->{size}; |
c000ae6e |
1506 | } |
1507 | |
c0507636 |
1508 | sub free_meth { return '_add_free_blist_sector' } |
1509 | |
c000ae6e |
1510 | sub bucket_size { |
1511 | my $self = shift; |
2432d6cc |
1512 | unless ( $self->{bucket_size} ) { |
1513 | my $e = $self->engine; |
6de4e4e9 |
1514 | # Key + head (location) + transactions (location + staleness-counter) |
17164f8a |
1515 | my $location_size = $e->byte_size + $e->num_txns * ( $e->byte_size + 4 ); |
6de4e4e9 |
1516 | $self->{bucket_size} = $e->hash_size + $location_size; |
2432d6cc |
1517 | } |
1518 | return $self->{bucket_size}; |
3976d8c9 |
1519 | } |
8fbac729 |
1520 | |
65bd261b |
1521 | # XXX This is such a poor hack. I need to rethink this code. |
6a4f323c |
1522 | sub chopped_up { |
1523 | my $self = shift; |
1524 | |
1525 | my $e = $self->engine; |
1526 | |
625a24b4 |
1527 | my @buckets; |
6a4f323c |
1528 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
65bd261b |
1529 | my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size; |
1530 | my $md5 = $e->storage->read_at( $spot, $e->hash_size ); |
6a4f323c |
1531 | |
1532 | last if $md5 eq $e->blank_md5; |
1533 | |
1534 | my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size ); |
65bd261b |
1535 | push @buckets, [ $spot, $md5 . $rest ]; |
6a4f323c |
1536 | } |
1537 | |
625a24b4 |
1538 | return @buckets; |
6a4f323c |
1539 | } |
1540 | |
1541 | sub write_at_next_open { |
1542 | my $self = shift; |
65bd261b |
1543 | my ($entry) = @_; |
6a4f323c |
1544 | |
1545 | #XXX This is such a hack! |
625a24b4 |
1546 | $self->{_next_open} = 0 unless exists $self->{_next_open}; |
6a4f323c |
1547 | |
65bd261b |
1548 | my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size; |
1549 | $self->engine->storage->print_at( $spot, $entry ); |
1550 | |
1551 | return $spot; |
6a4f323c |
1552 | } |
1553 | |
3976d8c9 |
1554 | sub has_md5 { |
c000ae6e |
1555 | my $self = shift; |
2432d6cc |
1556 | unless ( exists $self->{found} ) { |
1557 | $self->find_md5; |
1558 | } |
1559 | return $self->{found}; |
c000ae6e |
1560 | } |
1561 | |
1562 | sub find_md5 { |
1563 | my $self = shift; |
c000ae6e |
1564 | |
2432d6cc |
1565 | $self->{found} = undef; |
1566 | $self->{idx} = -1; |
c000ae6e |
1567 | |
d938be6a |
1568 | if ( @_ ) { |
1569 | $self->{key_md5} = shift; |
1570 | } |
1571 | |
2432d6cc |
1572 | # If we don't have an MD5, then what are we supposed to do? |
1573 | unless ( exists $self->{key_md5} ) { |
6f999f6e |
1574 | DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" ); |
2432d6cc |
1575 | } |
8cb9205a |
1576 | |
2432d6cc |
1577 | my $e = $self->engine; |
1578 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
1579 | my $potential = $e->storage->read_at( |
1580 | $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size, |
1581 | ); |
1582 | |
1583 | if ( $potential eq $e->blank_md5 ) { |
1584 | $self->{idx} = $idx; |
1585 | return; |
1586 | } |
8cb9205a |
1587 | |
2432d6cc |
1588 | if ( $potential eq $self->{key_md5} ) { |
1589 | $self->{found} = 1; |
1590 | $self->{idx} = $idx; |
1591 | return; |
8cb9205a |
1592 | } |
c000ae6e |
1593 | } |
1594 | |
1595 | return; |
3976d8c9 |
1596 | } |
1597 | |
1598 | sub write_md5 { |
1599 | my $self = shift; |
2432d6cc |
1600 | my ($args) = @_; |
2432d6cc |
1601 | |
6f999f6e |
1602 | DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key}; |
1603 | DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5}; |
1604 | DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value}; |
3976d8c9 |
1605 | |
1606 | my $engine = $self->engine; |
6f999f6e |
1607 | |
1608 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
1609 | |
2432d6cc |
1610 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
6f999f6e |
1611 | $engine->add_entry( $args->{trans_id}, $spot ); |
4eee718c |
1612 | |
2432d6cc |
1613 | unless ($self->{found}) { |
4eee718c |
1614 | my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
6f999f6e |
1615 | engine => $engine, |
2432d6cc |
1616 | data => $args->{key}, |
4eee718c |
1617 | }); |
1618 | |
1619 | $engine->storage->print_at( $spot, |
2432d6cc |
1620 | $args->{key_md5}, |
6f999f6e |
1621 | pack( $StP{$engine->byte_size}, $key_sector->offset ), |
4eee718c |
1622 | ); |
1623 | } |
1624 | |
6f999f6e |
1625 | my $loc = $spot |
2432d6cc |
1626 | + $engine->hash_size |
1627 | + $engine->byte_size |
17164f8a |
1628 | + $args->{trans_id} * ( $engine->byte_size + 4 ); |
6f999f6e |
1629 | |
1630 | $engine->storage->print_at( $loc, |
2432d6cc |
1631 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
6de4e4e9 |
1632 | pack( 'N', $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
2432d6cc |
1633 | ); |
1634 | } |
1635 | |
1636 | sub mark_deleted { |
1637 | my $self = shift; |
1638 | my ($args) = @_; |
6f999f6e |
1639 | $args ||= {}; |
1640 | |
1641 | my $engine = $self->engine; |
1642 | |
1643 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
2432d6cc |
1644 | |
1645 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
6f999f6e |
1646 | $engine->add_entry( $args->{trans_id}, $spot ); |
1647 | |
1648 | my $loc = $spot |
1649 | + $engine->hash_size |
1650 | + $engine->byte_size |
17164f8a |
1651 | + $args->{trans_id} * ( $engine->byte_size + 4 ); |
6f999f6e |
1652 | |
1653 | $engine->storage->print_at( $loc, |
1654 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
6de4e4e9 |
1655 | pack( 'N', $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
3976d8c9 |
1656 | ); |
1657 | } |
1658 | |
e86cef36 |
1659 | sub delete_md5 { |
3976d8c9 |
1660 | my $self = shift; |
2432d6cc |
1661 | my ($args) = @_; |
3976d8c9 |
1662 | |
e86cef36 |
1663 | my $engine = $self->engine; |
2432d6cc |
1664 | return undef unless $self->{found}; |
4eee718c |
1665 | |
1666 | # Save the location so that we can free the data |
2432d6cc |
1667 | my $location = $self->get_data_location_for({ |
1668 | allow_head => 0, |
1669 | }); |
1670 | my $key_sector = $self->get_key_for; |
4eee718c |
1671 | |
6f999f6e |
1672 | #XXX This isn't going to work right and you know it! This eradicates data |
1673 | # that we're not ready to eradicate just yet. |
2432d6cc |
1674 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
4eee718c |
1675 | $engine->storage->print_at( $spot, |
1676 | $engine->storage->read_at( |
1677 | $spot + $self->bucket_size, |
2432d6cc |
1678 | $self->bucket_size * ( $engine->num_txns - $self->{idx} - 1 ), |
4eee718c |
1679 | ), |
1680 | chr(0) x $self->bucket_size, |
e86cef36 |
1681 | ); |
1682 | |
3ed26433 |
1683 | $key_sector->free; |
1684 | |
ed38e772 |
1685 | my $data_sector = $self->engine->_load_sector( $location ); |
1686 | my $data = $data_sector->data; |
ed38e772 |
1687 | $data_sector->free; |
5c0f86e1 |
1688 | |
1689 | return $data; |
e86cef36 |
1690 | } |
1691 | |
ed38e772 |
1692 | sub get_data_location_for { |
e86cef36 |
1693 | my $self = shift; |
2432d6cc |
1694 | my ($args) = @_; |
1695 | $args ||= {}; |
1696 | |
1697 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
1698 | $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id}; |
1699 | $args->{idx} = $self->{idx} unless exists $args->{idx}; |
e86cef36 |
1700 | |
6de4e4e9 |
1701 | my $e = $self->engine; |
1702 | |
1703 | my $spot = $self->offset + $self->base_size |
2432d6cc |
1704 | + $args->{idx} * $self->bucket_size |
6de4e4e9 |
1705 | + $e->hash_size |
1706 | + $e->byte_size |
17164f8a |
1707 | + $args->{trans_id} * ( $e->byte_size + 4 ); |
6de4e4e9 |
1708 | |
1709 | my $buffer = $e->storage->read_at( |
1710 | $spot, |
17164f8a |
1711 | $e->byte_size + 4, |
3976d8c9 |
1712 | ); |
6de4e4e9 |
1713 | my ($loc, $staleness) = unpack( $StP{$e->byte_size} . ' N', $buffer ); |
1714 | |
1715 | # We have found an entry that is old, so get rid of it |
41e27db3 |
1716 | if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) { |
6de4e4e9 |
1717 | $e->storage->print_at( |
1718 | $spot, |
1719 | pack( $StP{$e->byte_size} . ' N', (0) x 2 ), |
1720 | ); |
1721 | $loc = 0; |
1722 | } |
8cb9205a |
1723 | |
1724 | # If we're in a transaction and we never wrote to this location, try the |
1725 | # HEAD instead. |
2432d6cc |
1726 | if ( $args->{trans_id} && !$loc && $args->{allow_head} ) { |
1727 | return $self->get_data_location_for({ |
1728 | trans_id => 0, |
1729 | allow_head => 1, |
17164f8a |
1730 | idx => $args->{idx}, |
2432d6cc |
1731 | }); |
8cb9205a |
1732 | } |
2432d6cc |
1733 | return $loc <= 1 ? 0 : $loc; |
e86cef36 |
1734 | } |
1735 | |
1736 | sub get_data_for { |
1737 | my $self = shift; |
2432d6cc |
1738 | my ($args) = @_; |
1739 | $args ||= {}; |
e86cef36 |
1740 | |
2432d6cc |
1741 | return unless $self->{found}; |
1742 | my $location = $self->get_data_location_for({ |
1743 | allow_head => $args->{allow_head}, |
1744 | }); |
ed38e772 |
1745 | return $self->engine->_load_sector( $location ); |
1746 | } |
1747 | |
1748 | sub get_key_for { |
1749 | my $self = shift; |
1750 | my ($idx) = @_; |
2432d6cc |
1751 | $idx = $self->{idx} unless defined $idx; |
ed38e772 |
1752 | |
0f4ed906 |
1753 | if ( $idx >= $self->engine->max_buckets ) { |
1754 | DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" ); |
1755 | } |
1756 | |
ed38e772 |
1757 | my $location = $self->engine->storage->read_at( |
1758 | $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size, |
1759 | $self->engine->byte_size, |
1760 | ); |
1761 | $location = unpack( $StP{$self->engine->byte_size}, $location ); |
1762 | return unless $location; |
68369f26 |
1763 | return $self->engine->_load_sector( $location ); |
3976d8c9 |
1764 | } |
696cadb7 |
1765 | |
8af340bf |
1766 | package DBM::Deep::Engine::Sector::Index; |
76c68c87 |
1767 | |
1768 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1769 | |
1770 | sub _init { |
1771 | my $self = shift; |
1772 | |
1773 | my $engine = $self->engine; |
1774 | |
1775 | unless ( $self->offset ) { |
1776 | my $leftover = $self->size - $self->base_size; |
1777 | |
c0507636 |
1778 | $self->{offset} = $engine->_request_index_sector( $self->size ); |
6a4f323c |
1779 | $engine->storage->print_at( $self->offset, $engine->SIG_INDEX ); # Sector type |
8af340bf |
1780 | # Skip staleness counter |
b6fc126b |
1781 | $engine->storage->print_at( $self->offset + $self->base_size, |
d58fd793 |
1782 | chr(0) x $leftover, # Zero-fill the rest |
76c68c87 |
1783 | ); |
1784 | } |
1785 | |
76c68c87 |
1786 | return $self; |
1787 | } |
1788 | |
76c68c87 |
1789 | sub size { |
1790 | my $self = shift; |
1791 | unless ( $self->{size} ) { |
1792 | my $e = $self->engine; |
d58fd793 |
1793 | $self->{size} = $self->base_size + $e->byte_size * $e->hash_chars; |
76c68c87 |
1794 | } |
1795 | return $self->{size}; |
1796 | } |
1797 | |
c0507636 |
1798 | sub free_meth { return '_add_free_index_sector' } |
1799 | |
d938be6a |
1800 | sub free { |
1801 | my $self = shift; |
1802 | my $e = $self->engine; |
1803 | |
1804 | for my $i ( 0 .. $e->hash_chars - 1 ) { |
1805 | my $l = $self->location_for( $i ) or next; |
1806 | $e->_load_sector( $l )->free; |
1807 | } |
1808 | |
1809 | $self->SUPER::free(); |
1810 | } |
1811 | |
6a4f323c |
1812 | sub _loc_for { |
1813 | my $self = shift; |
1814 | my ($idx) = @_; |
1815 | return $self->offset + $self->base_size + $idx * $self->engine->byte_size; |
1816 | } |
1817 | |
1818 | sub get_entry { |
d938be6a |
1819 | my $self = shift; |
1820 | my ($idx) = @_; |
1821 | |
1822 | my $e = $self->engine; |
1823 | |
0f4ed906 |
1824 | die "get_entry: Out of range ($idx)" |
1825 | if $idx < 0 || $idx >= $e->hash_chars; |
1826 | |
d938be6a |
1827 | return unpack( |
1828 | $StP{$e->byte_size}, |
6a4f323c |
1829 | $e->storage->read_at( $self->_loc_for( $idx ), $e->byte_size ), |
1830 | ); |
1831 | } |
1832 | |
1833 | sub set_entry { |
1834 | my $self = shift; |
1835 | my ($idx, $loc) = @_; |
1836 | |
0f4ed906 |
1837 | my $e = $self->engine; |
1838 | |
1839 | die "set_entry: Out of range ($idx)" |
1840 | if $idx < 0 || $idx >= $e->hash_chars; |
1841 | |
6a4f323c |
1842 | $self->engine->storage->print_at( |
1843 | $self->_loc_for( $idx ), |
0f4ed906 |
1844 | pack( $StP{$e->byte_size}, $loc ), |
d938be6a |
1845 | ); |
1846 | } |
1847 | |
76c68c87 |
1848 | 1; |
1849 | __END__ |