Commit | Line | Data |
fb451ba6 |
1 | package DBM::Deep::Engine2; |
2 | |
3 | use base 'DBM::Deep::Engine'; |
4 | |
5 | use 5.6.0; |
6 | |
7 | use strict; |
8 | use warnings; |
9 | |
10 | our $VERSION = q(0.99_03); |
11 | |
12 | use Fcntl qw( :DEFAULT :flock ); |
13 | use Scalar::Util (); |
14 | |
15 | # File-wide notes: |
16 | # * Every method in here assumes that the _storage has been appropriately |
17 | # safeguarded. This can be anything from flock() to some sort of manual |
18 | # mutex. But, it's the caller's responsability to make sure that this has |
19 | # been done. |
20 | |
21 | # Setup file and tag signatures. These should never change. |
22 | sub SIG_FILE () { 'DPDB' } |
23 | sub SIG_HEADER () { 'h' } |
24 | sub SIG_INTERNAL () { 'i' } |
25 | sub SIG_HASH () { 'H' } |
26 | sub SIG_ARRAY () { 'A' } |
27 | sub SIG_NULL () { 'N' } |
28 | sub SIG_DATA () { 'D' } |
29 | sub SIG_INDEX () { 'I' } |
30 | sub SIG_BLIST () { 'B' } |
31 | sub SIG_FREE () { 'F' } |
32 | sub SIG_KEYS () { 'K' } |
33 | sub SIG_SIZE () { 1 } |
34 | |
35 | # This is the transaction ID for the HEAD |
36 | sub HEAD () { 0 } |
37 | |
38 | sub read_value { |
39 | my $self = shift; |
40 | my ($trans_id, $base_offset, $key) = @_; |
41 | |
42 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
43 | offset => $base_offset, |
44 | trans_id => $trans_id, |
45 | allow_head => 1, |
46 | }); |
47 | die "Attempt to use a deleted value" if $_is_del; |
48 | die "Internal error!" if !$_val_offset; |
49 | |
50 | my ($key_offset) = $self->_find_key_offset({ |
51 | offset => $_val_offset, |
52 | key_md5 => $self->_apply_digest( $key ), |
53 | }); |
54 | return if !$key_offset; |
55 | |
56 | my ($val_offset, $is_del) = $self->_find_value_offset({ |
57 | offset => $key_offset, |
58 | trans_id => $trans_id, |
59 | allow_head => 1, |
60 | }); |
61 | return if $is_del; |
62 | die "Internal error!" if !$val_offset; |
63 | |
64 | return $self->_read_value({ |
129ea236 |
65 | keyloc => $key_offset, |
fb451ba6 |
66 | offset => $val_offset, |
67 | }); |
68 | } |
69 | |
70 | sub key_exists { |
71 | my $self = shift; |
72 | my ($trans_id, $base_offset, $key) = @_; |
73 | |
74 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
75 | offset => $base_offset, |
76 | trans_id => $trans_id, |
77 | allow_head => 1, |
78 | }); |
79 | die "Attempt to use a deleted value" if $_is_del; |
80 | die "Internal error!" if !$_val_offset; |
81 | |
82 | my ($key_offset) = $self->_find_key_offset({ |
83 | offset => $_val_offset, |
84 | key_md5 => $self->_apply_digest( $key ), |
85 | }); |
129ea236 |
86 | return '' if !$key_offset; |
fb451ba6 |
87 | |
88 | my ($val_offset, $is_del) = $self->_find_value_offset({ |
89 | offset => $key_offset, |
90 | trans_id => $trans_id, |
91 | allow_head => 1, |
92 | }); |
93 | |
129ea236 |
94 | return '' if $is_del; |
fb451ba6 |
95 | |
96 | die "Internal error!" if !$_val_offset; |
129ea236 |
97 | return 1; |
fb451ba6 |
98 | } |
99 | |
100 | sub get_next_key { |
101 | my $self = shift; |
129ea236 |
102 | my ($trans_id, $base_offset) = @_; |
103 | |
104 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
105 | offset => $base_offset, |
106 | trans_id => $trans_id, |
107 | allow_head => 1, |
108 | }); |
109 | die "Attempt to use a deleted value" if $_is_del; |
110 | die "Internal error!" if !$_val_offset; |
fb451ba6 |
111 | |
112 | # If the previous key was not specifed, start at the top and |
113 | # return the first one found. |
114 | my $temp; |
129ea236 |
115 | if ( @_ > 2 ) { |
fb451ba6 |
116 | $temp = { |
129ea236 |
117 | prev_md5 => $self->_apply_digest($_[2]), |
fb451ba6 |
118 | return_next => 0, |
119 | }; |
120 | } |
121 | else { |
122 | $temp = { |
123 | prev_md5 => chr(0) x $self->{hash_size}, |
124 | return_next => 1, |
125 | }; |
126 | } |
127 | |
129ea236 |
128 | return $self->traverse_index( $temp, $_val_offset, 0 ); |
fb451ba6 |
129 | } |
130 | |
131 | sub delete_key { |
132 | my $self = shift; |
133 | my ($trans_id, $base_offset, $key) = @_; |
134 | |
135 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
136 | offset => $base_offset, |
137 | trans_id => $trans_id, |
138 | allow_head => 1, |
139 | }); |
140 | die "Attempt to use a deleted value" if $_is_del; |
141 | die "Internal error!" if !$_val_offset; |
142 | |
143 | my ($key_offset, $bucket_tag) = $self->_find_key_offset({ |
144 | offset => $_val_offset, |
145 | key_md5 => $self->_apply_digest( $key ), |
146 | }); |
147 | return if !$key_offset; |
148 | |
149 | my $key_tag = $self->load_tag( $key_offset ); |
150 | |
129ea236 |
151 | my $value = $self->read_value( $trans_id, $base_offset, $key ); |
fb451ba6 |
152 | if ( $trans_id ) { |
153 | $self->_mark_as_deleted({ |
154 | tag => $key_tag, |
155 | trans_id => $trans_id, |
156 | }); |
157 | } |
158 | else { |
fb451ba6 |
159 | if ( my @transactions = $self->_storage->current_transactions ) { |
160 | foreach my $other_trans_id ( @transactions ) { |
161 | next if $self->_has_keyloc_entry({ |
162 | tag => $key_tag, |
163 | trans_id => $other_trans_id, |
164 | }); |
165 | $self->write_value( $other_trans_id, $base_offset, $key, $value ); |
166 | } |
167 | } |
129ea236 |
168 | |
169 | $self->_mark_as_deleted({ |
170 | tag => $key_tag, |
171 | trans_id => $trans_id, |
172 | }); |
173 | # $self->_remove_key_offset({ |
174 | # offset => $_val_offset, |
175 | # key_md5 => $self->_apply_digest( $key ), |
176 | # }); |
fb451ba6 |
177 | } |
178 | |
129ea236 |
179 | return $value; |
fb451ba6 |
180 | } |
181 | |
182 | sub write_value { |
183 | my $self = shift; |
184 | my ($trans_id, $base_offset, $key, $value) = @_; |
185 | |
186 | # This verifies that only supported values will be stored. |
187 | { |
188 | my $r = Scalar::Util::reftype( $value ); |
189 | |
190 | last if !defined $r; |
191 | last if $r eq 'HASH'; |
192 | last if $r eq 'ARRAY'; |
193 | |
194 | $self->_throw_error( |
195 | "Storage of references of type '$r' is not supported." |
196 | ); |
197 | } |
198 | |
199 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
200 | offset => $base_offset, |
201 | trans_id => $trans_id, |
202 | allow_head => 1, |
203 | }); |
204 | die "Attempt to use a deleted value" if $_is_del; |
205 | die "Internal error!" if !$_val_offset; |
206 | |
207 | my ($key_offset, $bucket_tag) = $self->_find_key_offset({ |
208 | offset => $_val_offset, |
209 | key_md5 => $self->_apply_digest( $key ), |
210 | create => 1, |
211 | }); |
212 | die "Cannot find/create new key offset!" if !$key_offset; |
213 | |
214 | my $key_tag = $self->load_tag( $key_offset ); |
215 | |
216 | if ( $trans_id ) { |
217 | if ( $bucket_tag->{is_new} ) { |
218 | # Must mark the HEAD as deleted because it doesn't exist |
219 | $self->_mark_as_deleted({ |
220 | tag => $key_tag, |
221 | trans_id => HEAD, |
222 | }); |
223 | } |
224 | } |
225 | else { |
226 | # If the HEAD isn't new, then we must take other transactions |
227 | # into account. If it is, then there can be no other transactions. |
228 | if ( !$bucket_tag->{is_new} ) { |
229 | my $old_value = $self->read_value( $trans_id, $base_offset, $key ); |
230 | if ( my @transactions = $self->_storage->current_transactions ) { |
231 | foreach my $other_trans_id ( @transactions ) { |
232 | next if $self->_has_keyloc_entry({ |
233 | tag => $key_tag, |
234 | trans_id => $other_trans_id, |
235 | }); |
236 | $self->write_value( $other_trans_id, $base_offset, $key, $old_value ); |
237 | } |
238 | } |
239 | } |
240 | } |
241 | |
40956c06 |
242 | my $value_loc = $self->_storage->request_space( |
243 | $self->_length_needed( $value, $key ), |
244 | ); |
245 | |
246 | $self->_add_key_offset({ |
247 | tag => $key_tag, |
248 | trans_id => $trans_id, |
249 | loc => $value_loc, |
fb451ba6 |
250 | }); |
251 | |
129ea236 |
252 | $self->_write_value( $key_offset, $value_loc, $key, $value, $key ); |
40956c06 |
253 | |
fb451ba6 |
254 | return 1; |
255 | } |
256 | |
257 | sub _find_value_offset { |
258 | my $self = shift; |
259 | my ($args) = @_; |
260 | |
261 | my $key_tag = $self->load_tag( $args->{offset} ); |
262 | |
263 | my @head; |
264 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
265 | my ($loc, $trans_id, $is_deleted) = unpack( |
266 | "$self->{long_pack} C C", |
267 | substr( $key_tag->{content}, $i * $self->{key_size}, $self->{key_size} ), |
268 | ); |
269 | |
270 | if ( $trans_id == HEAD ) { |
271 | @head = ($loc, $is_deleted); |
272 | } |
273 | |
274 | next if $loc && $args->{trans_id} != $trans_id; |
275 | return( $loc, $is_deleted ); |
276 | } |
277 | |
278 | return @head if $args->{allow_head}; |
279 | return; |
280 | } |
281 | |
fb451ba6 |
282 | sub _find_key_offset { |
283 | my $self = shift; |
284 | my ($args) = @_; |
285 | |
286 | my $bucket_tag = $self->load_tag( $args->{offset} ) |
287 | or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
288 | |
fb451ba6 |
289 | #XXX What happens when $ch >= $self->{hash_size} ?? |
290 | for (my $ch = 0; $bucket_tag->{signature} ne SIG_BLIST; $ch++) { |
291 | my $num = ord substr($args->{key_md5}, $ch, 1); |
292 | |
293 | my $ref_loc = $bucket_tag->{offset} + ($num * $self->{long_size}); |
294 | $bucket_tag = $self->index_lookup( $bucket_tag, $num ); |
295 | |
296 | if (!$bucket_tag) { |
297 | return if !$args->{create}; |
298 | |
299 | my $loc = $self->_storage->request_space( |
300 | $self->tag_size( $self->{bucket_list_size} ), |
301 | ); |
302 | |
303 | $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) ); |
304 | |
305 | $bucket_tag = $self->write_tag( |
306 | $loc, SIG_BLIST, |
307 | chr(0)x$self->{bucket_list_size}, |
308 | ); |
309 | |
310 | $bucket_tag->{ref_loc} = $ref_loc; |
311 | $bucket_tag->{ch} = $ch; |
312 | $bucket_tag->{is_new} = 1; |
313 | |
314 | last; |
315 | } |
316 | |
317 | $bucket_tag->{ch} = $ch; |
318 | $bucket_tag->{ref_loc} = $ref_loc; |
319 | } |
320 | |
321 | # Need to create a new keytag, too |
322 | if ( $bucket_tag->{is_new} ) { |
323 | my $keytag_loc = $self->_storage->request_space( |
324 | $self->tag_size( $self->{keyloc_size} ), |
325 | ); |
326 | |
327 | substr( $bucket_tag->{content}, 0, $self->{key_size} ) = |
328 | $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc ); |
329 | |
330 | $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} ); |
331 | |
332 | $self->write_tag( |
333 | $keytag_loc, SIG_KEYS, |
334 | chr(0)x$self->{keyloc_size}, |
335 | ); |
336 | |
337 | return( $keytag_loc, $bucket_tag ); |
338 | } |
339 | else { |
40956c06 |
340 | my ($key, $subloc, $index); |
fb451ba6 |
341 | BUCKET: |
342 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
40956c06 |
343 | ($key, $subloc) = $self->_get_key_subloc( |
fb451ba6 |
344 | $bucket_tag->{content}, $i, |
345 | ); |
346 | |
347 | next BUCKET if $subloc && $key ne $args->{key_md5}; |
40956c06 |
348 | |
349 | # Keep track of where we are, in case we need to create a new |
350 | # entry. |
351 | $index = $i; |
352 | last; |
fb451ba6 |
353 | } |
40956c06 |
354 | |
355 | # Either we have a subloc to return or we don't want to create a new |
356 | # entry. Either way, we need to return now. |
357 | return ($subloc, $bucket_tag) if $subloc || !$args->{create}; |
358 | |
359 | my $keytag_loc = $self->_storage->request_space( |
360 | $self->tag_size( $self->{keyloc_size} ), |
361 | ); |
362 | |
363 | # There's space left in this bucket |
364 | if ( defined $index ) { |
365 | substr( $bucket_tag->{content}, $index * $self->{key_size}, $self->{key_size} ) = |
366 | $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc ); |
367 | |
368 | $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} ); |
369 | } |
370 | # We need to split the index |
371 | else { |
372 | $self->split_index( $bucket_tag, $args->{key_md5}, $keytag_loc ); |
373 | } |
374 | |
375 | $self->write_tag( |
376 | $keytag_loc, SIG_KEYS, |
377 | chr(0)x$self->{keyloc_size}, |
378 | ); |
379 | |
380 | return( $keytag_loc, $bucket_tag ); |
fb451ba6 |
381 | } |
382 | |
383 | return; |
384 | } |
385 | |
386 | sub _read_value { |
387 | my $self = shift; |
388 | my ($args) = @_; |
389 | |
129ea236 |
390 | return $self->read_from_loc( $args->{keyloc}, $args->{offset} ); |
fb451ba6 |
391 | } |
392 | |
393 | sub _mark_as_deleted { |
394 | my $self = shift; |
395 | my ($args) = @_; |
396 | |
397 | my $is_changed; |
398 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
399 | my ($loc, $trans_id, $is_deleted) = unpack( |
400 | "$self->{long_pack} C C", |
401 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ), |
402 | ); |
403 | |
129ea236 |
404 | last unless $loc || $is_deleted; |
fb451ba6 |
405 | |
406 | if ( $trans_id == $args->{trans_id} ) { |
407 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack( |
408 | "$self->{long_pack} C C", |
409 | $loc, $trans_id, 1, |
40956c06 |
410 | ); |
129ea236 |
411 | $is_changed = 1; |
412 | last; |
fb451ba6 |
413 | } |
414 | } |
415 | |
416 | if ( $is_changed ) { |
417 | $self->_storage->print_at( |
418 | $args->{tag}{offset}, $args->{tag}{content}, |
419 | ); |
420 | } |
421 | |
422 | return 1; |
423 | } |
424 | |
425 | sub _has_keyloc_entry { |
426 | my $self = shift; |
427 | my ($args) = @_; |
428 | |
429 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
430 | my ($loc, $trans_id, $is_deleted) = unpack( |
431 | "$self->{long_pack} C C", |
432 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ), |
433 | ); |
434 | |
435 | return 1 if $trans_id == $args->{trans_id}; |
436 | } |
437 | |
438 | return; |
439 | } |
440 | |
441 | sub _remove_key_offset { |
442 | my $self = shift; |
443 | my ($args) = @_; |
444 | |
445 | my $is_changed; |
446 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
447 | my ($loc, $trans_id, $is_deleted) = unpack( |
448 | "$self->{long_pack} C C", |
449 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ), |
450 | ); |
451 | |
452 | if ( $trans_id == $args->{trans_id} ) { |
453 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = ''; |
454 | $args->{tag}{content} .= chr(0) x $self->{key_size}; |
455 | $is_changed = 1; |
456 | redo; |
457 | } |
458 | } |
459 | |
460 | if ( $is_changed ) { |
461 | $self->_storage->print_at( |
462 | $args->{tag}{offset}, $args->{tag}{content}, |
463 | ); |
464 | } |
465 | |
466 | return 1; |
467 | } |
468 | |
40956c06 |
469 | sub _add_key_offset { |
fb451ba6 |
470 | my $self = shift; |
471 | my ($args) = @_; |
472 | |
40956c06 |
473 | my $is_changed; |
474 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
475 | my ($loc, $trans_id, $is_deleted) = unpack( |
476 | "$self->{long_pack} C C", |
477 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ), |
478 | ); |
fb451ba6 |
479 | |
40956c06 |
480 | if ( $trans_id == $args->{trans_id} || (!$loc && !$is_deleted) ) { |
481 | substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack( |
482 | "$self->{long_pack} C C", |
483 | $args->{loc}, $args->{trans_id}, 0, |
484 | ); |
485 | $is_changed = 1; |
486 | last; |
487 | } |
488 | } |
489 | |
490 | if ( $is_changed ) { |
491 | $self->_storage->print_at( |
492 | $args->{tag}{offset}, $args->{tag}{content}, |
493 | ); |
494 | } |
495 | else { |
496 | die "Why didn't _add_key_offset() change something?!\n"; |
497 | } |
498 | |
499 | return 1; |
fb451ba6 |
500 | } |
501 | |
502 | sub setup_fh { |
503 | my $self = shift; |
504 | my ($obj) = @_; |
505 | |
506 | # Need to remove use of $fh here |
507 | my $fh = $self->_storage->{fh}; |
508 | flock $fh, LOCK_EX; |
509 | |
510 | #XXX The duplication of calculate_sizes needs to go away |
511 | unless ( $obj->{base_offset} ) { |
512 | my $bytes_read = $self->read_file_header; |
513 | |
514 | $self->calculate_sizes; |
515 | |
516 | ## |
517 | # File is empty -- write header and master index |
518 | ## |
519 | if (!$bytes_read) { |
520 | $self->_storage->audit( "# Database created on" ); |
521 | |
522 | $self->write_file_header; |
523 | |
524 | $obj->{base_offset} = $self->_storage->request_space( |
525 | $self->tag_size( $self->{keyloc_size} ), |
526 | ); |
527 | |
528 | my $value_spot = $self->_storage->request_space( |
529 | $self->tag_size( $self->{index_size} ), |
530 | ); |
531 | |
532 | $self->write_tag( |
533 | $obj->{base_offset}, SIG_KEYS, |
129ea236 |
534 | pack( "$self->{long_pack} C C", $value_spot, HEAD, 0 ), |
535 | chr(0) x ($self->{index_size} - $self->{key_size}), |
fb451ba6 |
536 | ); |
537 | |
538 | $self->write_tag( |
539 | $value_spot, $obj->_type, |
540 | chr(0)x$self->{index_size}, |
541 | ); |
542 | |
543 | # Flush the filehandle |
544 | my $old_fh = select $fh; |
545 | my $old_af = $|; $| = 1; $| = $old_af; |
546 | select $old_fh; |
547 | } |
548 | else { |
549 | $obj->{base_offset} = $bytes_read; |
550 | |
129ea236 |
551 | my ($_val_offset, $_is_del) = $self->_find_value_offset({ |
552 | offset => $obj->{base_offset}, |
553 | trans_id => HEAD, |
554 | allow_head => 1, |
555 | }); |
556 | die "Attempt to use a deleted value" if $_is_del; |
557 | die "Internal error!" if !$_val_offset; |
558 | |
fb451ba6 |
559 | ## |
560 | # Get our type from master index header |
561 | ## |
129ea236 |
562 | my $tag = $self->load_tag($_val_offset); |
fb451ba6 |
563 | unless ( $tag ) { |
564 | flock $fh, LOCK_UN; |
565 | $self->_throw_error("Corrupted file, no master index record"); |
566 | } |
567 | |
568 | unless ($obj->_type eq $tag->{signature}) { |
569 | flock $fh, LOCK_UN; |
570 | $self->_throw_error("File type mismatch"); |
571 | } |
572 | } |
573 | } |
574 | else { |
575 | $self->calculate_sizes; |
576 | } |
577 | |
578 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
579 | $self->_storage->set_inode; |
580 | |
581 | flock $fh, LOCK_UN; |
582 | |
583 | return 1; |
584 | } |
585 | |
586 | 1; |
587 | __END__ |