Commit | Line | Data |
696cadb7 |
1 | package DBM::Deep::Engine3; |
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 | |
696cadb7 |
32 | ################################################################################ |
33 | |
8fbac729 |
34 | # Please refer to the pack() documentation for further information |
35 | my %StP = ( |
b4e17919 |
36 | 1 => 'C', # Unsigned char value (no order specified, presumably ASCII) |
8fbac729 |
37 | 2 => 'n', # Unsigned short in "network" (big-endian) order |
38 | 4 => 'N', # Unsigned long in "network" (big-endian) order |
39 | 8 => 'Q', # Usigned quad (no order specified, presumably machine-dependent) |
c83524c6 |
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 | |
508 | sub clear_entries { |
509 | my $self = shift; |
6f999f6e |
510 | delete $self->{entries}{$self->trans_id}; |
511 | } |
512 | |
c9f02899 |
513 | ################################################################################ |
b9ec359f |
514 | |
c9f02899 |
515 | { |
516 | my $header_fixed = length( SIG_FILE ) + 1 + 4 + 4; |
696cadb7 |
517 | |
c9f02899 |
518 | sub _write_file_header { |
519 | my $self = shift; |
696cadb7 |
520 | |
d58fd793 |
521 | my $header_var = 1 + 1 + 4 + 4 * $self->num_txns + 3 * $self->byte_size; |
696cadb7 |
522 | |
c9f02899 |
523 | my $loc = $self->storage->request_space( $header_fixed + $header_var ); |
c83524c6 |
524 | |
c9f02899 |
525 | $self->storage->print_at( $loc, |
526 | SIG_FILE, |
527 | SIG_HEADER, |
528 | pack('N', 1), # header version - at this point, we're at 9 bytes |
529 | pack('N', $header_var), # header size |
530 | # --- Above is $header_fixed. Below is $header_var |
531 | pack('C', $self->byte_size), |
532 | pack('C', $self->max_buckets), |
b4e17919 |
533 | pack('N', 0 ), # Transaction activeness bitfield |
534 | pack('N' . $self->num_txns, 0 x $self->num_txns ), # Transaction staleness counters |
c9f02899 |
535 | pack($StP{$self->byte_size}, 0), # Start of free chain (blist size) |
536 | pack($StP{$self->byte_size}, 0), # Start of free chain (data size) |
d58fd793 |
537 | pack($StP{$self->byte_size}, 0), # Start of free chain (index size) |
c9f02899 |
538 | ); |
696cadb7 |
539 | |
c9f02899 |
540 | $self->set_trans_loc( $header_fixed + 2 ); |
cf03415a |
541 | $self->set_chains_loc( $header_fixed + 2 + 4 + 4 * $self->num_txns ); |
696cadb7 |
542 | |
c9f02899 |
543 | return; |
696cadb7 |
544 | } |
545 | |
c9f02899 |
546 | sub _read_file_header { |
547 | my $self = shift; |
696cadb7 |
548 | |
c9f02899 |
549 | my $buffer = $self->storage->read_at( 0, $header_fixed ); |
550 | return unless length($buffer); |
696cadb7 |
551 | |
c9f02899 |
552 | my ($file_signature, $sig_header, $header_version, $size) = unpack( |
553 | 'A4 A N N', $buffer |
554 | ); |
b9ec359f |
555 | |
c9f02899 |
556 | unless ( $file_signature eq SIG_FILE ) { |
557 | $self->storage->close; |
558 | DBM::Deep->_throw_error( "Signature not found -- file is not a Deep DB" ); |
559 | } |
696cadb7 |
560 | |
c9f02899 |
561 | unless ( $sig_header eq SIG_HEADER ) { |
562 | $self->storage->close; |
563 | DBM::Deep->_throw_error( "Old file version found." ); |
564 | } |
696cadb7 |
565 | |
c9f02899 |
566 | my $buffer2 = $self->storage->read_at( undef, $size ); |
567 | my @values = unpack( 'C C', $buffer2 ); |
696cadb7 |
568 | |
c9f02899 |
569 | $self->set_trans_loc( $header_fixed + 2 ); |
cf03415a |
570 | $self->set_chains_loc( $header_fixed + 2 + 4 + 4 * $self->num_txns ); |
c9f02899 |
571 | |
572 | if ( @values < 2 || grep { !defined } @values ) { |
573 | $self->storage->close; |
574 | DBM::Deep->_throw_error("Corrupted file - bad header"); |
575 | } |
576 | |
577 | #XXX Add warnings if values weren't set right |
578 | @{$self}{qw(byte_size max_buckets)} = @values; |
b9ec359f |
579 | |
d58fd793 |
580 | my $header_var = 1 + 1 + 4 + 4 * $self->num_txns + 3 * $self->byte_size; |
c9f02899 |
581 | unless ( $size eq $header_var ) { |
582 | $self->storage->close; |
583 | DBM::Deep->_throw_error( "Unexpected size found ($size <-> $header_var)." ); |
584 | } |
585 | |
586 | return length($buffer) + length($buffer2); |
587 | } |
696cadb7 |
588 | } |
589 | |
3976d8c9 |
590 | sub _load_sector { |
591 | my $self = shift; |
592 | my ($offset) = @_; |
593 | |
0f4ed906 |
594 | # Add a catch for offset of 0 or 1 |
595 | return if $offset <= 1; |
596 | |
3976d8c9 |
597 | my $type = $self->storage->read_at( $offset, 1 ); |
b9ec359f |
598 | return if $type eq chr(0); |
599 | |
3976d8c9 |
600 | if ( $type eq $self->SIG_ARRAY || $type eq $self->SIG_HASH ) { |
601 | return DBM::Deep::Engine::Sector::Reference->new({ |
602 | engine => $self, |
603 | type => $type, |
604 | offset => $offset, |
605 | }); |
606 | } |
2432d6cc |
607 | # XXX Don't we need key_md5 here? |
3976d8c9 |
608 | elsif ( $type eq $self->SIG_BLIST ) { |
609 | return DBM::Deep::Engine::Sector::BucketList->new({ |
610 | engine => $self, |
611 | type => $type, |
612 | offset => $offset, |
613 | }); |
614 | } |
d58fd793 |
615 | elsif ( $type eq $self->SIG_INDEX ) { |
616 | return DBM::Deep::Engine::Sector::Index->new({ |
617 | engine => $self, |
618 | type => $type, |
619 | offset => $offset, |
620 | }); |
621 | } |
68369f26 |
622 | elsif ( $type eq $self->SIG_NULL ) { |
623 | return DBM::Deep::Engine::Sector::Null->new({ |
624 | engine => $self, |
625 | type => $type, |
626 | offset => $offset, |
627 | }); |
628 | } |
629 | elsif ( $type eq $self->SIG_DATA ) { |
630 | return DBM::Deep::Engine::Sector::Scalar->new({ |
631 | engine => $self, |
632 | type => $type, |
633 | offset => $offset, |
634 | }); |
635 | } |
b9ec359f |
636 | # This was deleted from under us, so just return and let the caller figure it out. |
637 | elsif ( $type eq $self->SIG_FREE ) { |
638 | return; |
639 | } |
3976d8c9 |
640 | |
ed38e772 |
641 | die "'$offset': Don't know what to do with type '$type'\n"; |
3976d8c9 |
642 | } |
643 | |
644 | sub _apply_digest { |
645 | my $self = shift; |
646 | return $self->{digest}->(@_); |
647 | } |
648 | |
c0507636 |
649 | sub _add_free_blist_sector { shift->_add_free_sector( 0, @_ ) } |
650 | sub _add_free_data_sector { shift->_add_free_sector( 1, @_ ) } |
651 | sub _add_free_index_sector { shift->_add_free_sector( 2, @_ ) } |
652 | |
ed38e772 |
653 | sub _add_free_sector { |
654 | my $self = shift; |
c0507636 |
655 | my ($multiple, $offset, $size) = @_; |
b9ec359f |
656 | |
c0507636 |
657 | my $chains_offset = $multiple * $self->byte_size; |
b9ec359f |
658 | |
8af340bf |
659 | my $storage = $self->storage; |
660 | |
661 | # Increment staleness. |
c0507636 |
662 | # XXX Can this increment+modulo be done by "&= 0x1" ? |
d58fd793 |
663 | my $staleness = unpack( $StP{STALE_SIZE()}, $storage->read_at( $offset + SIG_SIZE, STALE_SIZE ) ); |
664 | $staleness = ($staleness + 1 ) % ( 2 ** ( 8 * STALE_SIZE ) ); |
665 | $storage->print_at( $offset + SIG_SIZE, pack( $StP{STALE_SIZE()}, $staleness ) ); |
b9ec359f |
666 | |
8af340bf |
667 | my $old_head = $storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
668 | |
669 | $storage->print_at( $self->chains_loc + $chains_offset, |
b9ec359f |
670 | pack( $StP{$self->byte_size}, $offset ), |
671 | ); |
672 | |
8af340bf |
673 | # Record the old head in the new sector after the signature and staleness counter |
d58fd793 |
674 | $storage->print_at( $offset + SIG_SIZE + STALE_SIZE, $old_head ); |
b9ec359f |
675 | } |
676 | |
c0507636 |
677 | sub _request_blist_sector { shift->_request_sector( 0, @_ ) } |
678 | sub _request_data_sector { shift->_request_sector( 1, @_ ) } |
679 | sub _request_index_sector { shift->_request_sector( 2, @_ ) } |
680 | |
b9ec359f |
681 | sub _request_sector { |
682 | my $self = shift; |
c0507636 |
683 | my ($multiple, $size) = @_; |
b9ec359f |
684 | |
c0507636 |
685 | my $chains_offset = $multiple * $self->byte_size; |
b9ec359f |
686 | |
687 | my $old_head = $self->storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
688 | my $loc = unpack( $StP{$self->byte_size}, $old_head ); |
689 | |
690 | # We don't have any free sectors of the right size, so allocate a new one. |
691 | unless ( $loc ) { |
8af340bf |
692 | my $offset = $self->storage->request_space( $size ); |
693 | |
694 | # Zero out the new sector. This also guarantees correct increases |
695 | # in the filesize. |
696 | $self->storage->print_at( $offset, chr(0) x $size ); |
697 | |
698 | return $offset; |
b9ec359f |
699 | } |
700 | |
8af340bf |
701 | # Read the new head after the signature and the staleness counter |
d58fd793 |
702 | my $new_head = $self->storage->read_at( $loc + SIG_SIZE + STALE_SIZE, $self->byte_size ); |
b9ec359f |
703 | $self->storage->print_at( $self->chains_loc + $chains_offset, $new_head ); |
704 | |
705 | return $loc; |
ed38e772 |
706 | } |
707 | |
696cadb7 |
708 | ################################################################################ |
709 | |
3976d8c9 |
710 | sub storage { $_[0]{storage} } |
711 | sub byte_size { $_[0]{byte_size} } |
712 | sub hash_size { $_[0]{hash_size} } |
6a4f323c |
713 | sub hash_chars { $_[0]{hash_chars} } |
3976d8c9 |
714 | sub num_txns { $_[0]{num_txns} } |
715 | sub max_buckets { $_[0]{max_buckets} } |
c000ae6e |
716 | sub blank_md5 { chr(0) x $_[0]->hash_size } |
8fbac729 |
717 | |
8cb9205a |
718 | sub trans_id { $_[0]{trans_id} } |
719 | sub set_trans_id { $_[0]{trans_id} = $_[1] } |
720 | |
c9f02899 |
721 | sub trans_loc { $_[0]{trans_loc} } |
722 | sub set_trans_loc { $_[0]{trans_loc} = $_[1] } |
723 | |
b9ec359f |
724 | sub chains_loc { $_[0]{chains_loc} } |
725 | sub set_chains_loc { $_[0]{chains_loc} = $_[1] } |
726 | |
8fbac729 |
727 | ################################################################################ |
728 | |
0f4ed906 |
729 | package DBM::Deep::Iterator; |
ed38e772 |
730 | |
731 | sub new { |
732 | my $class = shift; |
733 | my ($args) = @_; |
734 | |
735 | my $self = bless { |
736 | breadcrumbs => [], |
737 | engine => $args->{engine}, |
738 | base_offset => $args->{base_offset}, |
ed38e772 |
739 | }, $class; |
740 | |
741 | Scalar::Util::weaken( $self->{engine} ); |
742 | |
743 | return $self; |
744 | } |
745 | |
0f4ed906 |
746 | sub reset { $_[0]{breadcrumbs} = [] } |
747 | |
748 | sub get_sector_iterator { |
ed38e772 |
749 | my $self = shift; |
0f4ed906 |
750 | my ($loc) = @_; |
751 | |
752 | my $sector = $self->{engine}->_load_sector( $loc ) |
753 | or return; |
754 | |
755 | if ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
756 | return DBM::Deep::Iterator::Index->new({ |
757 | iterator => $self, |
758 | sector => $sector, |
759 | }); |
760 | } |
761 | elsif ( $sector->isa( 'DBM::Deep::Engine::Sector::BucketList' ) ) { |
762 | return DBM::Deep::Iterator::BucketList->new({ |
763 | iterator => $self, |
764 | sector => $sector, |
765 | }); |
766 | } |
767 | else { |
768 | die "Why did $loc make a $sector?"; |
769 | } |
ed38e772 |
770 | } |
771 | |
772 | sub get_next_key { |
773 | my $self = shift; |
8af340bf |
774 | my ($obj) = @_; |
ed38e772 |
775 | |
776 | my $crumbs = $self->{breadcrumbs}; |
0f4ed906 |
777 | my $e = $self->{engine}; |
ed38e772 |
778 | |
779 | unless ( @$crumbs ) { |
780 | # This will be a Reference sector |
0f4ed906 |
781 | my $sector = $e->_load_sector( $self->{base_offset} ) |
b9ec359f |
782 | # If no sector is found, thist must have been deleted from under us. |
783 | or return; |
8af340bf |
784 | |
785 | if ( $sector->staleness != $obj->_staleness ) { |
786 | return; |
787 | } |
788 | |
0f4ed906 |
789 | my $loc = $sector->get_blist_loc |
790 | or return; |
791 | |
792 | push @$crumbs, $self->get_sector_iterator( $loc ); |
ed38e772 |
793 | } |
794 | |
0f4ed906 |
795 | FIND_NEXT_KEY: { |
796 | # We're at the end. |
797 | unless ( @$crumbs ) { |
ed38e772 |
798 | $self->reset; |
0f4ed906 |
799 | return; |
ed38e772 |
800 | } |
801 | |
0f4ed906 |
802 | my $iterator = $crumbs->[-1]; |
803 | |
804 | # This level is done. |
805 | if ( $iterator->at_end ) { |
806 | pop @$crumbs; |
807 | redo FIND_NEXT_KEY; |
2432d6cc |
808 | } |
809 | |
0f4ed906 |
810 | if ( $iterator->isa( 'DBM::Deep::Iterator::Index' ) ) { |
811 | # If we don't have any more, it will be caught at the |
812 | # prior check. |
813 | if ( my $next = $iterator->get_next_iterator ) { |
814 | push @$crumbs, $next; |
815 | } |
816 | redo FIND_NEXT_KEY; |
817 | } |
ed38e772 |
818 | |
0f4ed906 |
819 | unless ( $iterator->isa( 'DBM::Deep::Iterator::BucketList' ) ) { |
820 | DBM::Deep->_throw_error( |
821 | "Should have a bucketlist iterator here - instead have $iterator" |
822 | ); |
2432d6cc |
823 | } |
824 | |
0f4ed906 |
825 | # At this point, we have a BucketList iterator |
826 | my $key = $iterator->get_next_key; |
827 | if ( defined $key ) { |
828 | return $key; |
ed38e772 |
829 | } |
830 | |
0f4ed906 |
831 | # We hit the end of the bucketlist iterator, so redo |
832 | redo FIND_NEXT_KEY; |
833 | } |
834 | |
835 | DBM::Deep->_throw_error( "get_next_key(): How did we get here?" ); |
836 | } |
837 | |
838 | package DBM::Deep::Iterator::Index; |
839 | |
840 | sub new { |
841 | my $self = bless $_[1] => $_[0]; |
842 | $self->{curr_index} = 0; |
843 | return $self; |
844 | } |
845 | |
846 | sub at_end { |
847 | my $self = shift; |
848 | return $self->{curr_index} >= $self->{iterator}{engine}->hash_chars; |
849 | } |
850 | |
851 | sub get_next_iterator { |
852 | my $self = shift; |
853 | |
854 | my $loc; |
855 | while ( !$loc ) { |
856 | return if $self->at_end; |
857 | $loc = $self->{sector}->get_entry( $self->{curr_index}++ ); |
ed38e772 |
858 | } |
859 | |
0f4ed906 |
860 | return $self->{iterator}->get_sector_iterator( $loc ); |
861 | } |
862 | |
863 | package DBM::Deep::Iterator::BucketList; |
864 | |
865 | sub new { |
866 | my $self = bless $_[1] => $_[0]; |
867 | $self->{curr_index} = 0; |
868 | return $self; |
869 | } |
870 | |
871 | sub at_end { |
872 | my $self = shift; |
873 | return $self->{curr_index} >= $self->{iterator}{engine}->max_buckets; |
874 | } |
875 | |
876 | sub get_next_key { |
877 | my $self = shift; |
878 | |
879 | return if $self->at_end; |
880 | |
9ce79856 |
881 | my $data_loc = $self->{sector}->get_data_location_for({ |
882 | allow_head => 1, |
883 | idx => $self->{curr_index}++, |
884 | }) or return; |
885 | |
886 | my $key_sector = $self->{sector}->get_key_for( $self->{curr_index} - 1 ); |
887 | |
888 | #XXX Is this check necessary now? |
0f4ed906 |
889 | return unless $key_sector; |
890 | |
891 | return $key_sector->data; |
ed38e772 |
892 | } |
893 | |
3976d8c9 |
894 | package DBM::Deep::Engine::Sector; |
895 | |
896 | sub new { |
897 | my $self = bless $_[1], $_[0]; |
898 | Scalar::Util::weaken( $self->{engine} ); |
899 | $self->_init; |
900 | return $self; |
901 | } |
902 | sub _init {} |
2432d6cc |
903 | sub clone { die "Must be implemented in the child class" } |
3976d8c9 |
904 | |
905 | sub engine { $_[0]{engine} } |
906 | sub offset { $_[0]{offset} } |
907 | sub type { $_[0]{type} } |
908 | |
d58fd793 |
909 | sub base_size { |
910 | my $self = shift; |
911 | return $self->engine->SIG_SIZE + $self->engine->STALE_SIZE; |
912 | } |
b6fc126b |
913 | |
ed38e772 |
914 | sub free { |
915 | my $self = shift; |
916 | |
b6fc126b |
917 | my $e = $self->engine; |
918 | |
919 | $e->storage->print_at( $self->offset, $e->SIG_FREE ); |
8af340bf |
920 | # Skip staleness counter |
b6fc126b |
921 | $e->storage->print_at( $self->offset + $self->base_size, |
922 | chr(0) x ($self->size - $self->base_size), |
b9ec359f |
923 | ); |
924 | |
c0507636 |
925 | my $free_meth = $self->free_meth; |
926 | $e->$free_meth( $self->offset, $self->size ); |
ed38e772 |
927 | |
b9ec359f |
928 | return; |
ed38e772 |
929 | } |
3976d8c9 |
930 | |
931 | package DBM::Deep::Engine::Sector::Data; |
8fbac729 |
932 | |
933 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
934 | |
3976d8c9 |
935 | # This is in bytes |
936 | sub size { return 256 } |
c0507636 |
937 | sub free_meth { return '_add_free_data_sector' } |
3976d8c9 |
938 | |
2432d6cc |
939 | sub clone { |
940 | my $self = shift; |
941 | return ref($self)->new({ |
942 | engine => $self->engine, |
943 | data => $self->data, |
944 | type => $self->type, |
945 | }); |
946 | } |
947 | |
3976d8c9 |
948 | package DBM::Deep::Engine::Sector::Scalar; |
949 | |
950 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
951 | |
ad4ae302 |
952 | sub free { |
953 | my $self = shift; |
954 | |
955 | my $chain_loc = $self->chain_loc; |
956 | |
957 | $self->SUPER::free(); |
958 | |
959 | if ( $chain_loc ) { |
960 | $self->engine->_load_sector( $chain_loc )->free; |
961 | } |
962 | |
963 | return; |
964 | } |
965 | |
3976d8c9 |
966 | sub type { $_[0]{engine}->SIG_DATA } |
8fbac729 |
967 | sub _init { |
968 | my $self = shift; |
969 | |
970 | my $engine = $self->engine; |
971 | |
3976d8c9 |
972 | unless ( $self->offset ) { |
b6fc126b |
973 | my $data_section = $self->size - $self->base_size - 1 * $engine->byte_size - 1; |
3976d8c9 |
974 | |
c0507636 |
975 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
ad4ae302 |
976 | |
2432d6cc |
977 | my $data = delete $self->{data}; |
ad4ae302 |
978 | my $dlen = length $data; |
979 | my $continue = 1; |
980 | my $curr_offset = $self->offset; |
981 | while ( $continue ) { |
982 | |
983 | my $next_offset = 0; |
984 | |
985 | my ($leftover, $this_len, $chunk); |
986 | if ( $dlen > $data_section ) { |
987 | $leftover = 0; |
988 | $this_len = $data_section; |
989 | $chunk = substr( $data, 0, $this_len ); |
990 | |
991 | $dlen -= $data_section; |
c0507636 |
992 | $next_offset = $engine->_request_data_sector( $self->size ); |
ad4ae302 |
993 | $data = substr( $data, $this_len ); |
994 | } |
995 | else { |
996 | $leftover = $data_section - $dlen; |
997 | $this_len = $dlen; |
998 | $chunk = $data; |
999 | |
1000 | $continue = 0; |
1001 | } |
1002 | |
8af340bf |
1003 | $engine->storage->print_at( $curr_offset, $self->type ); # Sector type |
1004 | # Skip staleness |
d58fd793 |
1005 | $engine->storage->print_at( $curr_offset + $self->base_size, |
ad4ae302 |
1006 | pack( $StP{$engine->byte_size}, $next_offset ), # Chain loc |
1007 | pack( $StP{1}, $this_len ), # Data length |
1008 | $chunk, # Data to be stored in this sector |
1009 | chr(0) x $leftover, # Zero-fill the rest |
1010 | ); |
1011 | |
1012 | $curr_offset = $next_offset; |
1013 | } |
3976d8c9 |
1014 | |
1015 | return; |
1016 | } |
1017 | } |
1018 | |
1019 | sub data_length { |
1020 | my $self = shift; |
1021 | |
ad4ae302 |
1022 | my $buffer = $self->engine->storage->read_at( |
b6fc126b |
1023 | $self->offset + $self->base_size + $self->engine->byte_size, 1 |
8fbac729 |
1024 | ); |
ad4ae302 |
1025 | |
1026 | return unpack( $StP{1}, $buffer ); |
1027 | } |
1028 | |
1029 | sub chain_loc { |
1030 | my $self = shift; |
1031 | my $chain_loc = $self->engine->storage->read_at( |
b6fc126b |
1032 | $self->offset + $self->base_size, $self->engine->byte_size, |
ad4ae302 |
1033 | ); |
1034 | return unpack( $StP{$self->engine->byte_size}, $chain_loc ); |
3976d8c9 |
1035 | } |
1036 | |
1037 | sub data { |
1038 | my $self = shift; |
8fbac729 |
1039 | |
378b4748 |
1040 | my $data; |
1041 | while ( 1 ) { |
1042 | my $chain_loc = $self->chain_loc; |
ad4ae302 |
1043 | |
378b4748 |
1044 | $data .= $self->engine->storage->read_at( |
b6fc126b |
1045 | $self->offset + $self->base_size + $self->engine->byte_size + 1, $self->data_length, |
378b4748 |
1046 | ); |
ad4ae302 |
1047 | |
378b4748 |
1048 | last unless $chain_loc; |
1049 | |
1050 | $self = $self->engine->_load_sector( $chain_loc ); |
ad4ae302 |
1051 | } |
1052 | |
1053 | return $data; |
8fbac729 |
1054 | } |
1055 | |
68369f26 |
1056 | package DBM::Deep::Engine::Sector::Null; |
1057 | |
1058 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
1059 | |
1060 | sub type { $_[0]{engine}->SIG_NULL } |
1061 | sub data_length { 0 } |
1062 | sub data { return } |
1063 | |
1064 | sub _init { |
1065 | my $self = shift; |
1066 | |
1067 | my $engine = $self->engine; |
1068 | |
1069 | unless ( $self->offset ) { |
b6fc126b |
1070 | my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1; |
68369f26 |
1071 | |
c0507636 |
1072 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
8af340bf |
1073 | $engine->storage->print_at( $self->offset, $self->type ); # Sector type |
1074 | # Skip staleness counter |
b6fc126b |
1075 | $engine->storage->print_at( $self->offset + $self->base_size, |
68369f26 |
1076 | pack( $StP{$engine->byte_size}, 0 ), # Chain loc |
1077 | pack( $StP{1}, $self->data_length ), # Data length |
1078 | chr(0) x $leftover, # Zero-fill the rest |
1079 | ); |
1080 | |
1081 | return; |
1082 | } |
1083 | } |
1084 | |
3976d8c9 |
1085 | package DBM::Deep::Engine::Sector::Reference; |
8fbac729 |
1086 | |
3976d8c9 |
1087 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
1088 | |
1089 | sub _init { |
1090 | my $self = shift; |
1091 | |
d58fd793 |
1092 | my $e = $self->engine; |
3976d8c9 |
1093 | |
1094 | unless ( $self->offset ) { |
ba075714 |
1095 | my $classname = Scalar::Util::blessed( delete $self->{data} ); |
d58fd793 |
1096 | my $leftover = $self->size - $self->base_size - 2 * $e->byte_size; |
d4f34951 |
1097 | |
1098 | my $class_offset = 0; |
1099 | if ( defined $classname ) { |
1100 | my $class_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
d58fd793 |
1101 | engine => $e, |
d4f34951 |
1102 | data => $classname, |
1103 | }); |
1104 | $class_offset = $class_sector->offset; |
1105 | } |
3976d8c9 |
1106 | |
c0507636 |
1107 | $self->{offset} = $e->_request_data_sector( $self->size ); |
d58fd793 |
1108 | $e->storage->print_at( $self->offset, $self->type ); # Sector type |
8af340bf |
1109 | # Skip staleness counter |
d58fd793 |
1110 | $e->storage->print_at( $self->offset + $self->base_size, |
1111 | pack( $StP{$e->byte_size}, 0 ), # Index/BList loc |
1112 | pack( $StP{$e->byte_size}, $class_offset ), # Classname loc |
c0507636 |
1113 | chr(0) x $leftover, # Zero-fill the rest |
3976d8c9 |
1114 | ); |
8af340bf |
1115 | } |
1116 | else { |
d58fd793 |
1117 | $self->{type} = $e->storage->read_at( $self->offset, 1 ); |
3976d8c9 |
1118 | } |
764e6cb9 |
1119 | |
8af340bf |
1120 | $self->{staleness} = unpack( |
d58fd793 |
1121 | $StP{$e->STALE_SIZE}, |
1122 | $e->storage->read_at( $self->offset + $e->SIG_SIZE, $e->STALE_SIZE ), |
8af340bf |
1123 | ); |
764e6cb9 |
1124 | |
1125 | return; |
3976d8c9 |
1126 | } |
1127 | |
d938be6a |
1128 | sub free { |
1129 | my $self = shift; |
1130 | |
1131 | my $blist_loc = $self->get_blist_loc; |
1132 | $self->engine->_load_sector( $blist_loc )->free if $blist_loc; |
1133 | |
1134 | my $class_loc = $self->get_class_offset; |
1135 | $self->engine->_load_sector( $class_loc )->free if $class_loc; |
1136 | |
1137 | $self->SUPER::free(); |
1138 | } |
1139 | |
8af340bf |
1140 | sub staleness { $_[0]{staleness} } |
1141 | |
2432d6cc |
1142 | sub get_data_for { |
1143 | my $self = shift; |
1144 | my ($args) = @_; |
1145 | |
1146 | # Assume that the head is not allowed unless otherwise specified. |
1147 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
1148 | |
1149 | # Assume we don't create a new blist location unless otherwise specified. |
1150 | $args->{create} = 0 unless exists $args->{create}; |
1151 | |
1152 | my $blist = $self->get_bucket_list({ |
1153 | key_md5 => $args->{key_md5}, |
0f4ed906 |
1154 | key => $args->{key}, |
2432d6cc |
1155 | create => $args->{create}, |
1156 | }); |
1157 | return unless $blist && $blist->{found}; |
1158 | |
1159 | # At this point, $blist knows where the md5 is. What it -doesn't- know yet |
1160 | # is whether or not this transaction has this key. That's part of the next |
1161 | # function call. |
1162 | my $location = $blist->get_data_location_for({ |
1163 | allow_head => $args->{allow_head}, |
1164 | }) or return; |
1165 | |
1166 | return $self->engine->_load_sector( $location ); |
1167 | } |
1168 | |
1169 | sub write_data { |
1170 | my $self = shift; |
1171 | my ($args) = @_; |
1172 | |
1173 | my $blist = $self->get_bucket_list({ |
1174 | key_md5 => $args->{key_md5}, |
0f4ed906 |
1175 | key => $args->{key}, |
2432d6cc |
1176 | create => 1, |
6f999f6e |
1177 | }) or die "How did write_data fail (no blist)?!\n"; |
2432d6cc |
1178 | |
1179 | # Handle any transactional bookkeeping. |
1180 | if ( $self->engine->trans_id ) { |
d938be6a |
1181 | if ( ! $blist->has_md5 ) { |
2432d6cc |
1182 | $blist->mark_deleted({ |
1183 | trans_id => 0, |
1184 | }); |
1185 | } |
1186 | } |
1187 | else { |
cf03415a |
1188 | my @trans_ids = $self->engine->get_running_txn_ids; |
d938be6a |
1189 | if ( $blist->has_md5 ) { |
2432d6cc |
1190 | if ( @trans_ids ) { |
1191 | my $old_value = $blist->get_data_for; |
1192 | foreach my $other_trans_id ( @trans_ids ) { |
b4e17919 |
1193 | next if $blist->get_data_location_for({ |
1194 | trans_id => $other_trans_id, |
1195 | allow_head => 0, |
1196 | }); |
2432d6cc |
1197 | $blist->write_md5({ |
1198 | trans_id => $other_trans_id, |
1199 | key => $args->{key}, |
1200 | key_md5 => $args->{key_md5}, |
1201 | value => $old_value->clone, |
1202 | }); |
1203 | } |
1204 | } |
1205 | } |
1206 | else { |
1207 | if ( @trans_ids ) { |
1208 | foreach my $other_trans_id ( @trans_ids ) { |
1209 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1210 | $blist->mark_deleted({ |
1211 | trans_id => $other_trans_id, |
1212 | }); |
1213 | } |
1214 | } |
1215 | } |
1216 | } |
1217 | |
6f999f6e |
1218 | #XXX Is this safe to do transactionally? |
2432d6cc |
1219 | # Free the place we're about to write to. |
1220 | if ( $blist->get_data_location_for({ allow_head => 0 }) ) { |
1221 | $blist->get_data_for({ allow_head => 0 })->free; |
1222 | } |
1223 | |
1224 | $blist->write_md5({ |
1225 | key => $args->{key}, |
1226 | key_md5 => $args->{key_md5}, |
1227 | value => $args->{value}, |
1228 | }); |
1229 | } |
1230 | |
1231 | sub delete_key { |
1232 | my $self = shift; |
1233 | my ($args) = @_; |
1234 | |
1235 | # XXX What should happen if this fails? |
1236 | my $blist = $self->get_bucket_list({ |
1237 | key_md5 => $args->{key_md5}, |
1238 | }) or die "How did delete_key fail (no blist)?!\n"; |
1239 | |
6f999f6e |
1240 | # Save the location so that we can free the data |
1241 | my $location = $blist->get_data_location_for({ |
1242 | allow_head => 0, |
1243 | }); |
26897a1c |
1244 | my $old_value = $location && $self->engine->_load_sector( $location ); |
6f999f6e |
1245 | |
1246 | if ( $self->engine->trans_id == 0 ) { |
cf03415a |
1247 | my @trans_ids = $self->engine->get_running_txn_ids; |
6f999f6e |
1248 | if ( @trans_ids ) { |
1249 | foreach my $other_trans_id ( @trans_ids ) { |
1250 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1251 | $blist->write_md5({ |
1252 | trans_id => $other_trans_id, |
1253 | key => $args->{key}, |
1254 | key_md5 => $args->{key_md5}, |
1255 | value => $old_value->clone, |
1256 | }); |
1257 | } |
1258 | } |
1259 | } |
1260 | |
1261 | $blist->mark_deleted( $args ); |
1262 | |
26897a1c |
1263 | my $data; |
1264 | if ( $old_value ) { |
1265 | $data = $old_value->data; |
1266 | $old_value->free; |
1267 | } |
6f999f6e |
1268 | |
1269 | return $data; |
2432d6cc |
1270 | } |
1271 | |
3976d8c9 |
1272 | sub get_blist_loc { |
1273 | my $self = shift; |
1274 | |
2432d6cc |
1275 | my $e = $self->engine; |
b6fc126b |
1276 | my $blist_loc = $e->storage->read_at( $self->offset + $self->base_size, $e->byte_size ); |
2432d6cc |
1277 | return unpack( $StP{$e->byte_size}, $blist_loc ); |
3976d8c9 |
1278 | } |
1279 | |
1280 | sub get_bucket_list { |
1281 | my $self = shift; |
1282 | my ($args) = @_; |
4eee718c |
1283 | $args ||= {}; |
3976d8c9 |
1284 | |
1285 | # XXX Add in check here for recycling? |
1286 | |
1287 | my $engine = $self->engine; |
1288 | |
1289 | my $blist_loc = $self->get_blist_loc; |
1290 | |
1291 | # There's no index or blist yet |
1292 | unless ( $blist_loc ) { |
1293 | return unless $args->{create}; |
1294 | |
1295 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
2432d6cc |
1296 | engine => $engine, |
1297 | key_md5 => $args->{key_md5}, |
3976d8c9 |
1298 | }); |
2432d6cc |
1299 | |
b6fc126b |
1300 | $engine->storage->print_at( $self->offset + $self->base_size, |
3976d8c9 |
1301 | pack( $StP{$engine->byte_size}, $blist->offset ), |
1302 | ); |
2432d6cc |
1303 | |
3976d8c9 |
1304 | return $blist; |
1305 | } |
1306 | |
d938be6a |
1307 | # Add searching here through the index layers, if any |
1308 | my $sector = $engine->_load_sector( $blist_loc ) |
1309 | or die "Cannot read sector at $blist_loc in get_bucket_list()"; |
1310 | my $i = 0; |
1311 | my $last_sector = undef; |
1312 | while ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
6a4f323c |
1313 | $blist_loc = $sector->get_entry( ord( substr( $args->{key_md5}, $i++, 1 ) ) ); |
d938be6a |
1314 | $last_sector = $sector; |
625a24b4 |
1315 | if ( $blist_loc ) { |
1316 | $sector = $engine->_load_sector( $blist_loc ) |
1317 | or die "Cannot read sector at $blist_loc in get_bucket_list()"; |
1318 | } |
1319 | else { |
1320 | $sector = undef; |
1321 | last; |
1322 | } |
1323 | } |
1324 | |
1325 | # This means we went through the Index sector(s) and found an empty slot |
1326 | unless ( $sector ) { |
1327 | return unless $args->{create}; |
1328 | |
1329 | die "No last_sector when attempting to build a new entry" |
1330 | unless $last_sector; |
1331 | |
1332 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
1333 | engine => $engine, |
1334 | key_md5 => $args->{key_md5}, |
1335 | }); |
1336 | |
1337 | $last_sector->set_entry( ord( substr( $args->{key_md5}, $i - 1, 1 ) ) => $blist->offset ); |
1338 | |
1339 | return $blist; |
d938be6a |
1340 | } |
1341 | |
1342 | $sector->find_md5( $args->{key_md5} ); |
1343 | |
1344 | # See whether or not we need to reindex the bucketlist |
6a4f323c |
1345 | if ( !$sector->has_md5 && $args->{create} && $sector->{idx} == -1 ) { |
6a4f323c |
1346 | my $new_index = DBM::Deep::Engine::Sector::Index->new({ |
1347 | engine => $engine, |
1348 | }); |
1349 | |
1350 | my %blist_cache; |
0f4ed906 |
1351 | foreach my $md5 ( $sector->chopped_up ) { |
6a4f323c |
1352 | my $idx = ord( substr( $md5, $i, 1 ) ); |
1353 | |
0f4ed906 |
1354 | # XXX This is inefficient |
6a4f323c |
1355 | my $blist = $blist_cache{$idx} |
1356 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1357 | engine => $engine, |
1358 | }); |
1359 | |
1360 | $new_index->set_entry( $idx => $blist->offset ); |
1361 | |
1362 | $blist->write_at_next_open( $md5 ); |
1363 | } |
1364 | |
0f4ed906 |
1365 | # Handle the new item separately. |
1366 | { |
1367 | my $idx = ord( substr( $args->{key_md5}, $i, 1 ) ); |
1368 | my $blist = $blist_cache{$idx} |
1369 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1370 | engine => $engine, |
1371 | }); |
1372 | |
1373 | $new_index->set_entry( $idx => $blist->offset ); |
1374 | |
1375 | #XXX THIS IS HACKY! |
1376 | $blist->find_md5( $args->{key_md5} ); |
1377 | $blist->write_md5({ |
1378 | key => $args->{key}, |
1379 | key_md5 => $args->{key_md5}, |
1380 | value => DBM::Deep::Engine::Sector::Null->new({ |
1381 | engine => $engine, |
1382 | data => undef, |
1383 | }), |
1384 | }); |
1385 | } |
1386 | |
6a4f323c |
1387 | if ( $last_sector ) { |
1388 | $last_sector->set_entry( |
1389 | ord( substr( $args->{key_md5}, $i - 1, 1 ) ), |
1390 | $new_index->offset, |
1391 | ); |
1392 | } else { |
1393 | $engine->storage->print_at( $self->offset + $self->base_size, |
1394 | pack( $StP{$engine->byte_size}, $new_index->offset ), |
1395 | ); |
1396 | } |
1397 | |
1398 | $sector->free; |
1399 | |
1400 | $sector = $blist_cache{ ord( substr( $args->{key_md5}, $i, 1 ) ) }; |
1401 | $sector->find_md5( $args->{key_md5} ); |
d938be6a |
1402 | } |
1403 | |
1404 | return $sector; |
3976d8c9 |
1405 | } |
1406 | |
d938be6a |
1407 | sub get_class_offset { |
ba075714 |
1408 | my $self = shift; |
1409 | |
d938be6a |
1410 | my $e = $self->engine; |
1411 | return unpack( |
1412 | $StP{$e->byte_size}, |
1413 | $e->storage->read_at( |
1414 | $self->offset + $self->base_size + 1 * $e->byte_size, $e->byte_size, |
1415 | ), |
ba075714 |
1416 | ); |
d938be6a |
1417 | } |
1418 | |
1419 | sub get_classname { |
1420 | my $self = shift; |
1421 | |
1422 | my $class_offset = $self->get_class_offset; |
ba075714 |
1423 | |
d4f34951 |
1424 | return unless $class_offset; |
ba075714 |
1425 | |
d4f34951 |
1426 | return $self->engine->_load_sector( $class_offset )->data; |
ba075714 |
1427 | } |
1428 | |
764e6cb9 |
1429 | sub data { |
1430 | my $self = shift; |
1431 | |
1432 | my $new_obj = DBM::Deep->new({ |
1433 | type => $self->type, |
1434 | base_offset => $self->offset, |
8af340bf |
1435 | staleness => $self->staleness, |
764e6cb9 |
1436 | storage => $self->engine->storage, |
c9f02899 |
1437 | engine => $self->engine, |
764e6cb9 |
1438 | }); |
1439 | |
ba075714 |
1440 | if ( $self->engine->storage->{autobless} ) { |
1441 | my $classname = $self->get_classname; |
1442 | if ( defined $classname ) { |
1443 | bless $new_obj, $classname; |
1444 | } |
1445 | } |
1446 | |
764e6cb9 |
1447 | return $new_obj; |
1448 | } |
1449 | |
3976d8c9 |
1450 | package DBM::Deep::Engine::Sector::BucketList; |
1451 | |
1452 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1453 | |
1454 | sub _init { |
1455 | my $self = shift; |
1456 | |
1457 | my $engine = $self->engine; |
1458 | |
1459 | unless ( $self->offset ) { |
c000ae6e |
1460 | my $leftover = $self->size - $self->base_size; |
3976d8c9 |
1461 | |
c0507636 |
1462 | $self->{offset} = $engine->_request_blist_sector( $self->size ); |
8af340bf |
1463 | $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type |
1464 | # Skip staleness counter |
b6fc126b |
1465 | $engine->storage->print_at( $self->offset + $self->base_size, |
3976d8c9 |
1466 | chr(0) x $leftover, # Zero-fill the data |
1467 | ); |
1468 | } |
8fbac729 |
1469 | |
2432d6cc |
1470 | if ( $self->{key_md5} ) { |
1471 | $self->find_md5; |
1472 | } |
1473 | |
8fbac729 |
1474 | return $self; |
1475 | } |
8fbac729 |
1476 | |
3976d8c9 |
1477 | sub size { |
1478 | my $self = shift; |
2432d6cc |
1479 | unless ( $self->{size} ) { |
1480 | my $e = $self->engine; |
d938be6a |
1481 | # Base + numbuckets * bucketsize |
1482 | $self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size; |
2432d6cc |
1483 | } |
1484 | return $self->{size}; |
c000ae6e |
1485 | } |
1486 | |
c0507636 |
1487 | sub free_meth { return '_add_free_blist_sector' } |
1488 | |
c000ae6e |
1489 | sub bucket_size { |
1490 | my $self = shift; |
2432d6cc |
1491 | unless ( $self->{bucket_size} ) { |
1492 | my $e = $self->engine; |
6de4e4e9 |
1493 | # Key + head (location) + transactions (location + staleness-counter) |
17164f8a |
1494 | my $location_size = $e->byte_size + $e->num_txns * ( $e->byte_size + 4 ); |
6de4e4e9 |
1495 | $self->{bucket_size} = $e->hash_size + $location_size; |
2432d6cc |
1496 | } |
1497 | return $self->{bucket_size}; |
3976d8c9 |
1498 | } |
8fbac729 |
1499 | |
6a4f323c |
1500 | sub chopped_up { |
1501 | my $self = shift; |
1502 | |
1503 | my $e = $self->engine; |
1504 | |
625a24b4 |
1505 | my @buckets; |
6a4f323c |
1506 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
1507 | my $md5 = $e->storage->read_at( |
1508 | $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size, |
1509 | ); |
1510 | |
1511 | last if $md5 eq $e->blank_md5; |
1512 | |
1513 | my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size ); |
625a24b4 |
1514 | push @buckets, $md5 . $rest; |
6a4f323c |
1515 | } |
1516 | |
625a24b4 |
1517 | return @buckets; |
6a4f323c |
1518 | } |
1519 | |
1520 | sub write_at_next_open { |
1521 | my $self = shift; |
1522 | my ($md5) = @_; |
1523 | |
1524 | #XXX This is such a hack! |
625a24b4 |
1525 | $self->{_next_open} = 0 unless exists $self->{_next_open}; |
6a4f323c |
1526 | |
1527 | $self->engine->storage->print_at( |
625a24b4 |
1528 | $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size, |
6a4f323c |
1529 | $md5, |
1530 | ); |
1531 | } |
1532 | |
3976d8c9 |
1533 | sub has_md5 { |
c000ae6e |
1534 | my $self = shift; |
2432d6cc |
1535 | unless ( exists $self->{found} ) { |
1536 | $self->find_md5; |
1537 | } |
1538 | return $self->{found}; |
c000ae6e |
1539 | } |
1540 | |
1541 | sub find_md5 { |
1542 | my $self = shift; |
c000ae6e |
1543 | |
2432d6cc |
1544 | $self->{found} = undef; |
1545 | $self->{idx} = -1; |
c000ae6e |
1546 | |
d938be6a |
1547 | if ( @_ ) { |
1548 | $self->{key_md5} = shift; |
1549 | } |
1550 | |
2432d6cc |
1551 | # If we don't have an MD5, then what are we supposed to do? |
1552 | unless ( exists $self->{key_md5} ) { |
6f999f6e |
1553 | DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" ); |
2432d6cc |
1554 | } |
8cb9205a |
1555 | |
2432d6cc |
1556 | my $e = $self->engine; |
1557 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
1558 | my $potential = $e->storage->read_at( |
1559 | $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size, |
1560 | ); |
1561 | |
1562 | if ( $potential eq $e->blank_md5 ) { |
1563 | $self->{idx} = $idx; |
1564 | return; |
1565 | } |
8cb9205a |
1566 | |
2432d6cc |
1567 | if ( $potential eq $self->{key_md5} ) { |
1568 | $self->{found} = 1; |
1569 | $self->{idx} = $idx; |
1570 | return; |
8cb9205a |
1571 | } |
c000ae6e |
1572 | } |
1573 | |
1574 | return; |
3976d8c9 |
1575 | } |
1576 | |
1577 | sub write_md5 { |
1578 | my $self = shift; |
2432d6cc |
1579 | my ($args) = @_; |
2432d6cc |
1580 | |
6f999f6e |
1581 | DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key}; |
1582 | DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5}; |
1583 | DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value}; |
3976d8c9 |
1584 | |
1585 | my $engine = $self->engine; |
6f999f6e |
1586 | |
1587 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
1588 | |
2432d6cc |
1589 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
6f999f6e |
1590 | $engine->add_entry( $args->{trans_id}, $spot ); |
4eee718c |
1591 | |
2432d6cc |
1592 | unless ($self->{found}) { |
4eee718c |
1593 | my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
6f999f6e |
1594 | engine => $engine, |
2432d6cc |
1595 | data => $args->{key}, |
4eee718c |
1596 | }); |
1597 | |
1598 | $engine->storage->print_at( $spot, |
2432d6cc |
1599 | $args->{key_md5}, |
6f999f6e |
1600 | pack( $StP{$engine->byte_size}, $key_sector->offset ), |
4eee718c |
1601 | ); |
1602 | } |
1603 | |
6f999f6e |
1604 | my $loc = $spot |
2432d6cc |
1605 | + $engine->hash_size |
1606 | + $engine->byte_size |
17164f8a |
1607 | + $args->{trans_id} * ( $engine->byte_size + 4 ); |
6f999f6e |
1608 | |
1609 | $engine->storage->print_at( $loc, |
2432d6cc |
1610 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
6de4e4e9 |
1611 | pack( 'N', $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
2432d6cc |
1612 | ); |
1613 | } |
1614 | |
1615 | sub mark_deleted { |
1616 | my $self = shift; |
1617 | my ($args) = @_; |
6f999f6e |
1618 | $args ||= {}; |
1619 | |
1620 | my $engine = $self->engine; |
1621 | |
1622 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
2432d6cc |
1623 | |
1624 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
6f999f6e |
1625 | $engine->add_entry( $args->{trans_id}, $spot ); |
1626 | |
1627 | my $loc = $spot |
1628 | + $engine->hash_size |
1629 | + $engine->byte_size |
17164f8a |
1630 | + $args->{trans_id} * ( $engine->byte_size + 4 ); |
6f999f6e |
1631 | |
1632 | $engine->storage->print_at( $loc, |
1633 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
6de4e4e9 |
1634 | pack( 'N', $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
3976d8c9 |
1635 | ); |
1636 | } |
1637 | |
e86cef36 |
1638 | sub delete_md5 { |
3976d8c9 |
1639 | my $self = shift; |
2432d6cc |
1640 | my ($args) = @_; |
3976d8c9 |
1641 | |
e86cef36 |
1642 | my $engine = $self->engine; |
2432d6cc |
1643 | return undef unless $self->{found}; |
4eee718c |
1644 | |
1645 | # Save the location so that we can free the data |
2432d6cc |
1646 | my $location = $self->get_data_location_for({ |
1647 | allow_head => 0, |
1648 | }); |
1649 | my $key_sector = $self->get_key_for; |
4eee718c |
1650 | |
6f999f6e |
1651 | #XXX This isn't going to work right and you know it! This eradicates data |
1652 | # that we're not ready to eradicate just yet. |
2432d6cc |
1653 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
4eee718c |
1654 | $engine->storage->print_at( $spot, |
1655 | $engine->storage->read_at( |
1656 | $spot + $self->bucket_size, |
2432d6cc |
1657 | $self->bucket_size * ( $engine->num_txns - $self->{idx} - 1 ), |
4eee718c |
1658 | ), |
1659 | chr(0) x $self->bucket_size, |
e86cef36 |
1660 | ); |
1661 | |
3ed26433 |
1662 | $key_sector->free; |
1663 | |
ed38e772 |
1664 | my $data_sector = $self->engine->_load_sector( $location ); |
1665 | my $data = $data_sector->data; |
ed38e772 |
1666 | $data_sector->free; |
5c0f86e1 |
1667 | |
1668 | return $data; |
e86cef36 |
1669 | } |
1670 | |
ed38e772 |
1671 | sub get_data_location_for { |
e86cef36 |
1672 | my $self = shift; |
2432d6cc |
1673 | my ($args) = @_; |
1674 | $args ||= {}; |
1675 | |
1676 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
1677 | $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id}; |
1678 | $args->{idx} = $self->{idx} unless exists $args->{idx}; |
e86cef36 |
1679 | |
6de4e4e9 |
1680 | my $e = $self->engine; |
1681 | |
1682 | my $spot = $self->offset + $self->base_size |
2432d6cc |
1683 | + $args->{idx} * $self->bucket_size |
6de4e4e9 |
1684 | + $e->hash_size |
1685 | + $e->byte_size |
17164f8a |
1686 | + $args->{trans_id} * ( $e->byte_size + 4 ); |
6de4e4e9 |
1687 | |
1688 | my $buffer = $e->storage->read_at( |
1689 | $spot, |
17164f8a |
1690 | $e->byte_size + 4, |
3976d8c9 |
1691 | ); |
6de4e4e9 |
1692 | my ($loc, $staleness) = unpack( $StP{$e->byte_size} . ' N', $buffer ); |
1693 | |
1694 | # We have found an entry that is old, so get rid of it |
41e27db3 |
1695 | if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) { |
6de4e4e9 |
1696 | $e->storage->print_at( |
1697 | $spot, |
1698 | pack( $StP{$e->byte_size} . ' N', (0) x 2 ), |
1699 | ); |
1700 | $loc = 0; |
1701 | } |
8cb9205a |
1702 | |
1703 | # If we're in a transaction and we never wrote to this location, try the |
1704 | # HEAD instead. |
2432d6cc |
1705 | if ( $args->{trans_id} && !$loc && $args->{allow_head} ) { |
1706 | return $self->get_data_location_for({ |
1707 | trans_id => 0, |
1708 | allow_head => 1, |
17164f8a |
1709 | idx => $args->{idx}, |
2432d6cc |
1710 | }); |
8cb9205a |
1711 | } |
2432d6cc |
1712 | return $loc <= 1 ? 0 : $loc; |
e86cef36 |
1713 | } |
1714 | |
1715 | sub get_data_for { |
1716 | my $self = shift; |
2432d6cc |
1717 | my ($args) = @_; |
1718 | $args ||= {}; |
e86cef36 |
1719 | |
2432d6cc |
1720 | return unless $self->{found}; |
1721 | my $location = $self->get_data_location_for({ |
1722 | allow_head => $args->{allow_head}, |
1723 | }); |
ed38e772 |
1724 | return $self->engine->_load_sector( $location ); |
1725 | } |
1726 | |
1727 | sub get_key_for { |
1728 | my $self = shift; |
1729 | my ($idx) = @_; |
2432d6cc |
1730 | $idx = $self->{idx} unless defined $idx; |
ed38e772 |
1731 | |
0f4ed906 |
1732 | if ( $idx >= $self->engine->max_buckets ) { |
1733 | DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" ); |
1734 | } |
1735 | |
ed38e772 |
1736 | my $location = $self->engine->storage->read_at( |
1737 | $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size, |
1738 | $self->engine->byte_size, |
1739 | ); |
1740 | $location = unpack( $StP{$self->engine->byte_size}, $location ); |
1741 | return unless $location; |
68369f26 |
1742 | return $self->engine->_load_sector( $location ); |
3976d8c9 |
1743 | } |
696cadb7 |
1744 | |
8af340bf |
1745 | package DBM::Deep::Engine::Sector::Index; |
76c68c87 |
1746 | |
1747 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1748 | |
1749 | sub _init { |
1750 | my $self = shift; |
1751 | |
1752 | my $engine = $self->engine; |
1753 | |
1754 | unless ( $self->offset ) { |
1755 | my $leftover = $self->size - $self->base_size; |
1756 | |
c0507636 |
1757 | $self->{offset} = $engine->_request_index_sector( $self->size ); |
6a4f323c |
1758 | $engine->storage->print_at( $self->offset, $engine->SIG_INDEX ); # Sector type |
8af340bf |
1759 | # Skip staleness counter |
b6fc126b |
1760 | $engine->storage->print_at( $self->offset + $self->base_size, |
d58fd793 |
1761 | chr(0) x $leftover, # Zero-fill the rest |
76c68c87 |
1762 | ); |
1763 | } |
1764 | |
76c68c87 |
1765 | return $self; |
1766 | } |
1767 | |
76c68c87 |
1768 | sub size { |
1769 | my $self = shift; |
1770 | unless ( $self->{size} ) { |
1771 | my $e = $self->engine; |
d58fd793 |
1772 | $self->{size} = $self->base_size + $e->byte_size * $e->hash_chars; |
76c68c87 |
1773 | } |
1774 | return $self->{size}; |
1775 | } |
1776 | |
c0507636 |
1777 | sub free_meth { return '_add_free_index_sector' } |
1778 | |
d938be6a |
1779 | sub free { |
1780 | my $self = shift; |
1781 | my $e = $self->engine; |
1782 | |
1783 | for my $i ( 0 .. $e->hash_chars - 1 ) { |
1784 | my $l = $self->location_for( $i ) or next; |
1785 | $e->_load_sector( $l )->free; |
1786 | } |
1787 | |
1788 | $self->SUPER::free(); |
1789 | } |
1790 | |
6a4f323c |
1791 | sub _loc_for { |
1792 | my $self = shift; |
1793 | my ($idx) = @_; |
1794 | return $self->offset + $self->base_size + $idx * $self->engine->byte_size; |
1795 | } |
1796 | |
1797 | sub get_entry { |
d938be6a |
1798 | my $self = shift; |
1799 | my ($idx) = @_; |
1800 | |
1801 | my $e = $self->engine; |
1802 | |
0f4ed906 |
1803 | die "get_entry: Out of range ($idx)" |
1804 | if $idx < 0 || $idx >= $e->hash_chars; |
1805 | |
d938be6a |
1806 | return unpack( |
1807 | $StP{$e->byte_size}, |
6a4f323c |
1808 | $e->storage->read_at( $self->_loc_for( $idx ), $e->byte_size ), |
1809 | ); |
1810 | } |
1811 | |
1812 | sub set_entry { |
1813 | my $self = shift; |
1814 | my ($idx, $loc) = @_; |
1815 | |
0f4ed906 |
1816 | my $e = $self->engine; |
1817 | |
1818 | die "set_entry: Out of range ($idx)" |
1819 | if $idx < 0 || $idx >= $e->hash_chars; |
1820 | |
6a4f323c |
1821 | $self->engine->storage->print_at( |
1822 | $self->_loc_for( $idx ), |
0f4ed906 |
1823 | pack( $StP{$e->byte_size}, $loc ), |
d938be6a |
1824 | ); |
1825 | } |
1826 | |
76c68c87 |
1827 | 1; |
1828 | __END__ |