Commit | Line | Data |
a20d9a3f |
1 | package DBM::Deep::Engine; |
2 | |
2120a181 |
3 | use 5.006_000; |
460b1067 |
4 | |
a20d9a3f |
5 | use strict; |
e9b0b5f0 |
6 | use warnings; |
a20d9a3f |
7 | |
151e0077 |
8 | our $VERSION = q(1.0001); |
86867f3a |
9 | |
359a01ac |
10 | use Scalar::Util (); |
a20d9a3f |
11 | |
21838116 |
12 | # File-wide notes: |
2120a181 |
13 | # * Every method in here assumes that the storage has been appropriately |
c3aafc14 |
14 | # safeguarded. This can be anything from flock() to some sort of manual |
15 | # mutex. But, it's the caller's responsability to make sure that this has |
16 | # been done. |
21838116 |
17 | |
8db25060 |
18 | # Setup file and tag signatures. These should never change. |
8db25060 |
19 | sub SIG_FILE () { 'DPDB' } |
460b1067 |
20 | sub SIG_HEADER () { 'h' } |
8db25060 |
21 | sub SIG_HASH () { 'H' } |
22 | sub SIG_ARRAY () { 'A' } |
8db25060 |
23 | sub SIG_NULL () { 'N' } |
24 | sub SIG_DATA () { 'D' } |
25 | sub SIG_INDEX () { 'I' } |
26 | sub SIG_BLIST () { 'B' } |
7b1e1aa1 |
27 | sub SIG_FREE () { 'F' } |
8db25060 |
28 | sub SIG_SIZE () { 1 } |
e9b0b5f0 |
29 | |
30 | my $STALE_SIZE = 2; |
8db25060 |
31 | |
2120a181 |
32 | # Please refer to the pack() documentation for further information |
33 | my %StP = ( |
e9b0b5f0 |
34 | 1 => 'C', # Unsigned char value (no order needed as it's just one byte) |
2120a181 |
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) |
38 | ); |
83371fe3 |
39 | |
c3aafc14 |
40 | ################################################################################ |
c3aafc14 |
41 | |
612969fb |
42 | sub new { |
43 | my $class = shift; |
44 | my ($args) = @_; |
45 | |
46 | my $self = bless { |
2120a181 |
47 | byte_size => 4, |
48 | |
49 | digest => undef, |
50 | hash_size => 16, # In bytes |
51 | hash_chars => 256, # Number of chars the algorithm uses per byte |
612969fb |
52 | max_buckets => 16, |
e9b0b5f0 |
53 | num_txns => 1, # The HEAD |
2120a181 |
54 | trans_id => 0, # Default to the HEAD |
460b1067 |
55 | |
e9b0b5f0 |
56 | data_sector_size => 64, # Size in bytes of each data sector |
57 | |
2120a181 |
58 | entries => {}, # This is the list of entries for transactions |
83371fe3 |
59 | storage => undef, |
612969fb |
60 | }, $class; |
61 | |
e9b0b5f0 |
62 | # Never allow byte_size to be set directly. |
63 | delete $args->{byte_size}; |
e0098e7f |
64 | if ( defined $args->{pack_size} ) { |
65 | if ( lc $args->{pack_size} eq 'small' ) { |
2120a181 |
66 | $args->{byte_size} = 2; |
e0098e7f |
67 | } |
68 | elsif ( lc $args->{pack_size} eq 'medium' ) { |
2120a181 |
69 | $args->{byte_size} = 4; |
e0098e7f |
70 | } |
71 | elsif ( lc $args->{pack_size} eq 'large' ) { |
2120a181 |
72 | $args->{byte_size} = 8; |
e0098e7f |
73 | } |
74 | else { |
2120a181 |
75 | DBM::Deep->_throw_error( "Unknown pack_size value: '$args->{pack_size}'" ); |
e0098e7f |
76 | } |
77 | } |
78 | |
fde3db1a |
79 | # Grab the parameters we want to use |
80 | foreach my $param ( keys %$self ) { |
81 | next unless exists $args->{$param}; |
3e9498a1 |
82 | $self->{$param} = $args->{$param}; |
fde3db1a |
83 | } |
84 | |
e9b0b5f0 |
85 | my %validations = ( |
86 | max_buckets => { floor => 16, ceil => 256 }, |
87 | num_txns => { floor => 1, ceil => 255 }, |
88 | data_sector_size => { floor => 32, ceil => 256 }, |
89 | ); |
90 | |
91 | while ( my ($attr, $c) = each %validations ) { |
92 | if ( !defined $self->{$attr} |
93 | || !length $self->{$attr} |
94 | || $self->{$attr} =~ /\D/ |
95 | || $self->{$attr} < $c->{floor} |
96 | ) { |
97 | $self->{$attr} = '(undef)' if !defined $self->{$attr}; |
98 | warn "Floor of $attr is $c->{floor}. Setting it to $c->{floor} from '$self->{$attr}'\n"; |
99 | $self->{$attr} = $c->{floor}; |
100 | } |
101 | elsif ( $self->{$attr} > $c->{ceil} ) { |
102 | warn "Ceiling of $attr is $c->{ceil}. Setting it to $c->{ceil} from '$self->{$attr}'\n"; |
103 | $self->{$attr} = $c->{ceil}; |
104 | } |
e0098e7f |
105 | } |
106 | |
2120a181 |
107 | if ( !$self->{digest} ) { |
108 | require Digest::MD5; |
109 | $self->{digest} = \&Digest::MD5::md5; |
110 | } |
111 | |
260a80b4 |
112 | return $self; |
113 | } |
114 | |
2120a181 |
115 | ################################################################################ |
460b1067 |
116 | |
2120a181 |
117 | sub read_value { |
c3aafc14 |
118 | my $self = shift; |
2120a181 |
119 | my ($obj, $key) = @_; |
120 | |
121 | # This will be a Reference sector |
122 | my $sector = $self->_load_sector( $obj->_base_offset ) |
123 | or return; |
124 | |
125 | if ( $sector->staleness != $obj->_staleness ) { |
126 | return; |
127 | } |
128 | |
129 | my $key_md5 = $self->_apply_digest( $key ); |
130 | |
131 | my $value_sector = $sector->get_data_for({ |
132 | key_md5 => $key_md5, |
133 | allow_head => 1, |
134 | }); |
135 | |
136 | unless ( $value_sector ) { |
137 | $value_sector = DBM::Deep::Engine::Sector::Null->new({ |
138 | engine => $self, |
139 | data => undef, |
140 | }); |
141 | |
142 | $sector->write_data({ |
143 | key_md5 => $key_md5, |
144 | key => $key, |
145 | value => $value_sector, |
146 | }); |
147 | } |
148 | |
149 | return $value_sector->data; |
c3aafc14 |
150 | } |
151 | |
2120a181 |
152 | sub get_classname { |
260a80b4 |
153 | my $self = shift; |
2120a181 |
154 | my ($obj) = @_; |
260a80b4 |
155 | |
2120a181 |
156 | # This will be a Reference sector |
157 | my $sector = $self->_load_sector( $obj->_base_offset ) |
158 | or DBM::Deep->_throw_error( "How did get_classname fail (no sector for '$obj')?!" ); |
612969fb |
159 | |
2120a181 |
160 | if ( $sector->staleness != $obj->_staleness ) { |
161 | return; |
162 | } |
ea2f6d67 |
163 | |
2120a181 |
164 | return $sector->get_classname; |
1bf65be7 |
165 | } |
166 | |
2120a181 |
167 | sub key_exists { |
0d0f3d5d |
168 | my $self = shift; |
2120a181 |
169 | my ($obj, $key) = @_; |
0d0f3d5d |
170 | |
2120a181 |
171 | # This will be a Reference sector |
172 | my $sector = $self->_load_sector( $obj->_base_offset ) |
173 | or return ''; |
0d0f3d5d |
174 | |
2120a181 |
175 | if ( $sector->staleness != $obj->_staleness ) { |
176 | return ''; |
177 | } |
0d0f3d5d |
178 | |
2120a181 |
179 | my $data = $sector->get_data_for({ |
180 | key_md5 => $self->_apply_digest( $key ), |
181 | allow_head => 1, |
182 | }); |
20b7f047 |
183 | |
2120a181 |
184 | # exists() returns 1 or '' for true/false. |
185 | return $data ? 1 : ''; |
0d0f3d5d |
186 | } |
187 | |
2120a181 |
188 | sub delete_key { |
e064ccd1 |
189 | my $self = shift; |
2120a181 |
190 | my ($obj, $key) = @_; |
e064ccd1 |
191 | |
2120a181 |
192 | my $sector = $self->_load_sector( $obj->_base_offset ) |
193 | or return; |
460b1067 |
194 | |
2120a181 |
195 | if ( $sector->staleness != $obj->_staleness ) { |
196 | return; |
197 | } |
198 | |
199 | return $sector->delete_key({ |
200 | key_md5 => $self->_apply_digest( $key ), |
201 | allow_head => 0, |
202 | }); |
203 | } |
204 | |
205 | sub write_value { |
206 | my $self = shift; |
207 | my ($obj, $key, $value) = @_; |
208 | |
209 | my $r = Scalar::Util::reftype( $value ) || ''; |
210 | { |
211 | last if $r eq ''; |
212 | last if $r eq 'HASH'; |
213 | last if $r eq 'ARRAY'; |
e064ccd1 |
214 | |
2120a181 |
215 | DBM::Deep->_throw_error( |
216 | "Storage of references of type '$r' is not supported." |
217 | ); |
460b1067 |
218 | } |
260a80b4 |
219 | |
2120a181 |
220 | my ($class, $type); |
221 | if ( !defined $value ) { |
222 | $class = 'DBM::Deep::Engine::Sector::Null'; |
223 | } |
224 | elsif ( $r eq 'ARRAY' || $r eq 'HASH' ) { |
225 | if ( $r eq 'ARRAY' && tied(@$value) ) { |
226 | DBM::Deep->_throw_error( "Cannot store something that is tied." ); |
227 | } |
228 | if ( $r eq 'HASH' && tied(%$value) ) { |
229 | DBM::Deep->_throw_error( "Cannot store something that is tied." ); |
230 | } |
231 | $class = 'DBM::Deep::Engine::Sector::Reference'; |
232 | $type = substr( $r, 0, 1 ); |
233 | } |
234 | else { |
235 | $class = 'DBM::Deep::Engine::Sector::Scalar'; |
460b1067 |
236 | } |
9b2370e0 |
237 | |
2120a181 |
238 | # This will be a Reference sector |
239 | my $sector = $self->_load_sector( $obj->_base_offset ) |
240 | or DBM::Deep->_throw_error( "Cannot write to a deleted spot in DBM::Deep." ); |
15ba72cc |
241 | |
2120a181 |
242 | if ( $sector->staleness != $obj->_staleness ) { |
243 | DBM::Deep->_throw_error( "Cannot write to a deleted spot in DBM::Deep.n" ); |
244 | } |
15ba72cc |
245 | |
2120a181 |
246 | # Create this after loading the reference sector in case something bad happens. |
247 | # This way, we won't allocate value sector(s) needlessly. |
248 | my $value_sector = $class->new({ |
249 | engine => $self, |
250 | data => $value, |
251 | type => $type, |
252 | }); |
253 | |
254 | $sector->write_data({ |
255 | key => $key, |
256 | key_md5 => $self->_apply_digest( $key ), |
257 | value => $value_sector, |
258 | }); |
259 | |
260 | # This code is to make sure we write all the values in the $value to the disk |
261 | # and to make sure all changes to $value after the assignment are reflected |
262 | # on disk. This may be counter-intuitive at first, but it is correct dwimmery. |
263 | # NOTE - simply tying $value won't perform a STORE on each value. Hence, the |
264 | # copy to a temp value. |
265 | if ( $r eq 'ARRAY' ) { |
266 | my @temp = @$value; |
267 | tie @$value, 'DBM::Deep', { |
268 | base_offset => $value_sector->offset, |
269 | staleness => $value_sector->staleness, |
270 | storage => $self->storage, |
271 | engine => $self, |
272 | }; |
273 | @$value = @temp; |
274 | bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value ); |
e064ccd1 |
275 | } |
2120a181 |
276 | elsif ( $r eq 'HASH' ) { |
277 | my %temp = %$value; |
278 | tie %$value, 'DBM::Deep', { |
279 | base_offset => $value_sector->offset, |
280 | staleness => $value_sector->staleness, |
281 | storage => $self->storage, |
282 | engine => $self, |
283 | }; |
e064ccd1 |
284 | |
2120a181 |
285 | %$value = %temp; |
286 | bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value ); |
287 | } |
460b1067 |
288 | |
2120a181 |
289 | return 1; |
e064ccd1 |
290 | } |
291 | |
2120a181 |
292 | # XXX Add staleness here |
293 | sub get_next_key { |
460b1067 |
294 | my $self = shift; |
2120a181 |
295 | my ($obj, $prev_key) = @_; |
70b55428 |
296 | |
2120a181 |
297 | # XXX Need to add logic about resetting the iterator if any key in the reference has changed |
298 | unless ( $prev_key ) { |
299 | $obj->{iterator} = DBM::Deep::Iterator->new({ |
300 | base_offset => $obj->_base_offset, |
301 | engine => $self, |
302 | }); |
303 | } |
118ba343 |
304 | |
2120a181 |
305 | return $obj->{iterator}->get_next_key( $obj ); |
306 | } |
118ba343 |
307 | |
2120a181 |
308 | ################################################################################ |
260a80b4 |
309 | |
2120a181 |
310 | sub setup_fh { |
311 | my $self = shift; |
312 | my ($obj) = @_; |
359a01ac |
313 | |
2120a181 |
314 | # We're opening the file. |
315 | unless ( $obj->_base_offset ) { |
316 | my $bytes_read = $self->_read_file_header; |
118ba343 |
317 | |
2120a181 |
318 | # Creating a new file |
319 | unless ( $bytes_read ) { |
320 | $self->_write_file_header; |
118ba343 |
321 | |
2120a181 |
322 | # 1) Create Array/Hash entry |
323 | my $initial_reference = DBM::Deep::Engine::Sector::Reference->new({ |
324 | engine => $self, |
325 | type => $obj->_type, |
326 | }); |
327 | $obj->{base_offset} = $initial_reference->offset; |
328 | $obj->{staleness} = $initial_reference->staleness; |
118ba343 |
329 | |
2120a181 |
330 | $self->storage->flush; |
118ba343 |
331 | } |
2120a181 |
332 | # Reading from an existing file |
118ba343 |
333 | else { |
334 | $obj->{base_offset} = $bytes_read; |
2120a181 |
335 | my $initial_reference = DBM::Deep::Engine::Sector::Reference->new({ |
336 | engine => $self, |
337 | offset => $obj->_base_offset, |
338 | }); |
339 | unless ( $initial_reference ) { |
340 | DBM::Deep->_throw_error("Corrupted file, no master index record"); |
359a01ac |
341 | } |
118ba343 |
342 | |
2120a181 |
343 | unless ($obj->_type eq $initial_reference->type) { |
344 | DBM::Deep->_throw_error("File type mismatch"); |
118ba343 |
345 | } |
2120a181 |
346 | |
347 | $obj->{staleness} = $initial_reference->staleness; |
118ba343 |
348 | } |
118ba343 |
349 | } |
2120a181 |
350 | |
351 | return 1; |
352 | } |
353 | |
354 | sub begin_work { |
355 | my $self = shift; |
356 | my ($obj) = @_; |
357 | |
358 | if ( $self->trans_id ) { |
359 | DBM::Deep->_throw_error( "Cannot begin_work within an active transaction" ); |
360 | } |
361 | |
362 | my @slots = $self->read_txn_slots; |
e9b0b5f0 |
363 | my $found; |
364 | for my $i ( 0 .. $#slots ) { |
2120a181 |
365 | next if $slots[$i]; |
e9b0b5f0 |
366 | |
2120a181 |
367 | $slots[$i] = 1; |
e9b0b5f0 |
368 | $self->set_trans_id( $i + 1 ); |
369 | $found = 1; |
2120a181 |
370 | last; |
371 | } |
e9b0b5f0 |
372 | unless ( $found ) { |
373 | DBM::Deep->_throw_error( "Cannot allocate transaction ID" ); |
374 | } |
2120a181 |
375 | $self->write_txn_slots( @slots ); |
376 | |
377 | if ( !$self->trans_id ) { |
378 | DBM::Deep->_throw_error( "Cannot begin_work - no available transactions" ); |
379 | } |
380 | |
381 | return; |
382 | } |
383 | |
384 | sub rollback { |
385 | my $self = shift; |
386 | my ($obj) = @_; |
387 | |
388 | if ( !$self->trans_id ) { |
389 | DBM::Deep->_throw_error( "Cannot rollback without an active transaction" ); |
390 | } |
391 | |
392 | # Each entry is the file location for a bucket that has a modification for |
393 | # this transaction. The entries need to be expunged. |
394 | foreach my $entry (@{ $self->get_entries } ) { |
395 | # Remove the entry here |
396 | my $read_loc = $entry |
397 | + $self->hash_size |
398 | + $self->byte_size |
e9b0b5f0 |
399 | + $self->byte_size |
400 | + ($self->trans_id - 1) * ( $self->byte_size + $STALE_SIZE ); |
2120a181 |
401 | |
402 | my $data_loc = $self->storage->read_at( $read_loc, $self->byte_size ); |
403 | $data_loc = unpack( $StP{$self->byte_size}, $data_loc ); |
404 | $self->storage->print_at( $read_loc, pack( $StP{$self->byte_size}, 0 ) ); |
405 | |
406 | if ( $data_loc > 1 ) { |
407 | $self->_load_sector( $data_loc )->free; |
408 | } |
260a80b4 |
409 | } |
e06824f8 |
410 | |
2120a181 |
411 | $self->clear_entries; |
70b55428 |
412 | |
2120a181 |
413 | my @slots = $self->read_txn_slots; |
e9b0b5f0 |
414 | $slots[$self->trans_id-1] = 0; |
2120a181 |
415 | $self->write_txn_slots( @slots ); |
416 | $self->inc_txn_staleness_counter( $self->trans_id ); |
417 | $self->set_trans_id( 0 ); |
6fde4ed2 |
418 | |
70b55428 |
419 | return 1; |
420 | } |
421 | |
2120a181 |
422 | sub commit { |
16d1ad9b |
423 | my $self = shift; |
2120a181 |
424 | my ($obj) = @_; |
425 | |
426 | if ( !$self->trans_id ) { |
427 | DBM::Deep->_throw_error( "Cannot commit without an active transaction" ); |
428 | } |
429 | |
430 | foreach my $entry (@{ $self->get_entries } ) { |
431 | # Overwrite the entry in head with the entry in trans_id |
432 | my $base = $entry |
433 | + $self->hash_size |
434 | + $self->byte_size; |
435 | |
436 | my $head_loc = $self->storage->read_at( $base, $self->byte_size ); |
437 | $head_loc = unpack( $StP{$self->byte_size}, $head_loc ); |
e9b0b5f0 |
438 | |
439 | my $spot = $base + $self->byte_size + ($self->trans_id - 1) * ( $self->byte_size + $STALE_SIZE ); |
2120a181 |
440 | my $trans_loc = $self->storage->read_at( |
e9b0b5f0 |
441 | $spot, $self->byte_size, |
2120a181 |
442 | ); |
443 | |
444 | $self->storage->print_at( $base, $trans_loc ); |
445 | $self->storage->print_at( |
e9b0b5f0 |
446 | $spot, |
447 | pack( $StP{$self->byte_size} . ' ' . $StP{$STALE_SIZE}, (0) x 2 ), |
2120a181 |
448 | ); |
449 | |
450 | if ( $head_loc > 1 ) { |
451 | $self->_load_sector( $head_loc )->free; |
452 | } |
453 | } |
454 | |
455 | $self->clear_entries; |
456 | |
457 | my @slots = $self->read_txn_slots; |
e9b0b5f0 |
458 | $slots[$self->trans_id-1] = 0; |
2120a181 |
459 | $self->write_txn_slots( @slots ); |
460 | $self->inc_txn_staleness_counter( $self->trans_id ); |
461 | $self->set_trans_id( 0 ); |
462 | |
463 | return 1; |
16d1ad9b |
464 | } |
465 | |
2120a181 |
466 | sub read_txn_slots { |
d4b1166e |
467 | my $self = shift; |
e9b0b5f0 |
468 | my $bl = $self->txn_bitfield_len; |
469 | my $num_bits = $bl * 8; |
470 | return split '', unpack( 'b'.$num_bits, |
2120a181 |
471 | $self->storage->read_at( |
e9b0b5f0 |
472 | $self->trans_loc, $bl, |
2120a181 |
473 | ) |
474 | ); |
475 | } |
20f7b20c |
476 | |
2120a181 |
477 | sub write_txn_slots { |
478 | my $self = shift; |
e9b0b5f0 |
479 | my $num_bits = $self->txn_bitfield_len * 8; |
2120a181 |
480 | $self->storage->print_at( $self->trans_loc, |
e9b0b5f0 |
481 | pack( 'b'.$num_bits, join('', @_) ), |
7dcefff3 |
482 | ); |
2120a181 |
483 | } |
484 | |
485 | sub get_running_txn_ids { |
486 | my $self = shift; |
487 | my @transactions = $self->read_txn_slots; |
e9b0b5f0 |
488 | my @trans_ids = map { $_+1} grep { $transactions[$_] } 0 .. $#transactions; |
2120a181 |
489 | } |
490 | |
491 | sub get_txn_staleness_counter { |
492 | my $self = shift; |
493 | my ($trans_id) = @_; |
20f7b20c |
494 | |
2120a181 |
495 | # Hardcode staleness of 0 for the HEAD |
496 | return 0 unless $trans_id; |
f37c15ab |
497 | |
e9b0b5f0 |
498 | return unpack( $StP{$STALE_SIZE}, |
2120a181 |
499 | $self->storage->read_at( |
e9b0b5f0 |
500 | $self->trans_loc + 4 + $STALE_SIZE * ($trans_id - 1), |
2120a181 |
501 | 4, |
502 | ) |
503 | ); |
d4b1166e |
504 | } |
505 | |
2120a181 |
506 | sub inc_txn_staleness_counter { |
d4b1166e |
507 | my $self = shift; |
2120a181 |
508 | my ($trans_id) = @_; |
20f7b20c |
509 | |
2120a181 |
510 | # Hardcode staleness of 0 for the HEAD |
511 | return unless $trans_id; |
20f7b20c |
512 | |
2120a181 |
513 | $self->storage->print_at( |
e9b0b5f0 |
514 | $self->trans_loc + 4 + $STALE_SIZE * ($trans_id - 1), |
515 | pack( $StP{$STALE_SIZE}, $self->get_txn_staleness_counter( $trans_id ) + 1 ), |
86867f3a |
516 | ); |
2120a181 |
517 | } |
20f7b20c |
518 | |
2120a181 |
519 | sub get_entries { |
520 | my $self = shift; |
521 | return [ keys %{ $self->{entries}{$self->trans_id} ||= {} } ]; |
d4b1166e |
522 | } |
523 | |
2120a181 |
524 | sub add_entry { |
ea2f6d67 |
525 | my $self = shift; |
2120a181 |
526 | my ($trans_id, $loc) = @_; |
ea2f6d67 |
527 | |
2120a181 |
528 | $self->{entries}{$trans_id} ||= {}; |
529 | $self->{entries}{$trans_id}{$loc} = undef; |
530 | } |
ea2f6d67 |
531 | |
2120a181 |
532 | # If the buckets are being relocated because of a reindexing, the entries |
533 | # mechanism needs to be made aware of it. |
534 | sub reindex_entry { |
535 | my $self = shift; |
536 | my ($old_loc, $new_loc) = @_; |
537 | |
538 | TRANS: |
539 | while ( my ($trans_id, $locs) = each %{ $self->{entries} } ) { |
540 | foreach my $orig_loc ( keys %{ $locs } ) { |
541 | if ( $orig_loc == $old_loc ) { |
542 | delete $locs->{orig_loc}; |
543 | $locs->{$new_loc} = undef; |
544 | next TRANS; |
545 | } |
546 | } |
ea2f6d67 |
547 | } |
ea2f6d67 |
548 | } |
549 | |
2120a181 |
550 | sub clear_entries { |
d4b1166e |
551 | my $self = shift; |
2120a181 |
552 | delete $self->{entries}{$self->trans_id}; |
553 | } |
eea0d863 |
554 | |
2120a181 |
555 | ################################################################################ |
eea0d863 |
556 | |
2120a181 |
557 | { |
558 | my $header_fixed = length( SIG_FILE ) + 1 + 4 + 4; |
e9b0b5f0 |
559 | my $this_file_version = 2; |
2120a181 |
560 | |
561 | sub _write_file_header { |
562 | my $self = shift; |
563 | |
e9b0b5f0 |
564 | my $nt = $self->num_txns; |
565 | my $bl = $self->txn_bitfield_len; |
566 | |
567 | my $header_var = 1 + 1 + 1 + 1 + $bl + $STALE_SIZE * ($nt - 1) + 3 * $self->byte_size; |
2120a181 |
568 | |
569 | my $loc = $self->storage->request_space( $header_fixed + $header_var ); |
570 | |
571 | $self->storage->print_at( $loc, |
572 | SIG_FILE, |
573 | SIG_HEADER, |
e9b0b5f0 |
574 | pack('N', $this_file_version), # At this point, we're at 9 bytes |
575 | pack('N', $header_var), # header size |
2120a181 |
576 | # --- Above is $header_fixed. Below is $header_var |
577 | pack('C', $self->byte_size), |
e9b0b5f0 |
578 | |
579 | # These shenanigans are to allow a 256 within a C |
580 | pack('C', $self->max_buckets - 1), |
581 | pack('C', $self->data_sector_size - 1), |
582 | |
583 | pack('C', $nt), |
584 | pack('C' . $bl, 0 ), # Transaction activeness bitfield |
585 | pack($StP{$STALE_SIZE}.($nt-1), 0 x ($nt-1) ), # Transaction staleness counters |
2120a181 |
586 | pack($StP{$self->byte_size}, 0), # Start of free chain (blist size) |
587 | pack($StP{$self->byte_size}, 0), # Start of free chain (data size) |
588 | pack($StP{$self->byte_size}, 0), # Start of free chain (index size) |
eea0d863 |
589 | ); |
eea0d863 |
590 | |
e9b0b5f0 |
591 | #XXX Set these less fragilely |
592 | $self->set_trans_loc( $header_fixed + 4 ); |
593 | $self->set_chains_loc( $header_fixed + 4 + $bl + $STALE_SIZE * ($nt-1) ); |
20f7b20c |
594 | |
2120a181 |
595 | return; |
c9b6d0d8 |
596 | } |
75be6413 |
597 | |
2120a181 |
598 | sub _read_file_header { |
599 | my $self = shift; |
ea2f6d67 |
600 | |
2120a181 |
601 | my $buffer = $self->storage->read_at( 0, $header_fixed ); |
602 | return unless length($buffer); |
019404df |
603 | |
e9b0b5f0 |
604 | my ($file_signature, $sig_header, $file_version, $size) = unpack( |
2120a181 |
605 | 'A4 A N N', $buffer |
606 | ); |
ea2f6d67 |
607 | |
2120a181 |
608 | unless ( $file_signature eq SIG_FILE ) { |
609 | $self->storage->close; |
610 | DBM::Deep->_throw_error( "Signature not found -- file is not a Deep DB" ); |
611 | } |
ea2f6d67 |
612 | |
2120a181 |
613 | unless ( $sig_header eq SIG_HEADER ) { |
614 | $self->storage->close; |
e9b0b5f0 |
615 | DBM::Deep->_throw_error( "Pre-1.00 file version found" ); |
616 | } |
617 | |
618 | unless ( $file_version == $this_file_version ) { |
619 | $self->storage->close; |
620 | DBM::Deep->_throw_error( |
621 | "Wrong file version found - " . $file_version . |
622 | " - expected " . $this_file_version |
623 | ); |
75be6413 |
624 | } |
504185fb |
625 | |
2120a181 |
626 | my $buffer2 = $self->storage->read_at( undef, $size ); |
e9b0b5f0 |
627 | my @values = unpack( 'C C C C', $buffer2 ); |
386bab6c |
628 | |
e9b0b5f0 |
629 | if ( @values != 4 || grep { !defined } @values ) { |
2120a181 |
630 | $self->storage->close; |
631 | DBM::Deep->_throw_error("Corrupted file - bad header"); |
ea2f6d67 |
632 | } |
633 | |
2120a181 |
634 | #XXX Add warnings if values weren't set right |
e9b0b5f0 |
635 | @{$self}{qw(byte_size max_buckets data_sector_size num_txns)} = @values; |
ea2f6d67 |
636 | |
e9b0b5f0 |
637 | # These shenangians are to allow a 256 within a C |
638 | $self->{max_buckets} += 1; |
639 | $self->{data_sector_size} += 1; |
640 | |
641 | my $bl = $self->txn_bitfield_len; |
642 | |
643 | my $header_var = scalar(@values) + $bl + $STALE_SIZE * ($self->num_txns - 1) + 3 * $self->byte_size; |
2120a181 |
644 | unless ( $size == $header_var ) { |
645 | $self->storage->close; |
646 | DBM::Deep->_throw_error( "Unexpected size found ($size <-> $header_var)." ); |
c9b6d0d8 |
647 | } |
20f7b20c |
648 | |
e9b0b5f0 |
649 | $self->set_trans_loc( $header_fixed + scalar(@values) ); |
650 | $self->set_chains_loc( $header_fixed + scalar(@values) + $bl + $STALE_SIZE * ($self->num_txns - 1) ); |
651 | |
2120a181 |
652 | return length($buffer) + length($buffer2); |
653 | } |
d5d7c51d |
654 | } |
655 | |
2120a181 |
656 | sub _load_sector { |
d5d7c51d |
657 | my $self = shift; |
2120a181 |
658 | my ($offset) = @_; |
d5d7c51d |
659 | |
2120a181 |
660 | # Add a catch for offset of 0 or 1 |
661 | return if $offset <= 1; |
d5d7c51d |
662 | |
2120a181 |
663 | my $type = $self->storage->read_at( $offset, 1 ); |
664 | return if $type eq chr(0); |
d5d7c51d |
665 | |
2120a181 |
666 | if ( $type eq $self->SIG_ARRAY || $type eq $self->SIG_HASH ) { |
667 | return DBM::Deep::Engine::Sector::Reference->new({ |
668 | engine => $self, |
669 | type => $type, |
670 | offset => $offset, |
671 | }); |
f37c15ab |
672 | } |
2120a181 |
673 | # XXX Don't we need key_md5 here? |
674 | elsif ( $type eq $self->SIG_BLIST ) { |
675 | return DBM::Deep::Engine::Sector::BucketList->new({ |
676 | engine => $self, |
677 | type => $type, |
678 | offset => $offset, |
679 | }); |
d5d7c51d |
680 | } |
2120a181 |
681 | elsif ( $type eq $self->SIG_INDEX ) { |
682 | return DBM::Deep::Engine::Sector::Index->new({ |
683 | engine => $self, |
684 | type => $type, |
685 | offset => $offset, |
686 | }); |
d5d7c51d |
687 | } |
2120a181 |
688 | elsif ( $type eq $self->SIG_NULL ) { |
689 | return DBM::Deep::Engine::Sector::Null->new({ |
690 | engine => $self, |
691 | type => $type, |
692 | offset => $offset, |
693 | }); |
d5d7c51d |
694 | } |
2120a181 |
695 | elsif ( $type eq $self->SIG_DATA ) { |
696 | return DBM::Deep::Engine::Sector::Scalar->new({ |
697 | engine => $self, |
698 | type => $type, |
699 | offset => $offset, |
700 | }); |
9d4fa373 |
701 | } |
2120a181 |
702 | # This was deleted from under us, so just return and let the caller figure it out. |
703 | elsif ( $type eq $self->SIG_FREE ) { |
704 | return; |
20f7b20c |
705 | } |
d4b1166e |
706 | |
2120a181 |
707 | DBM::Deep->_throw_error( "'$offset': Don't know what to do with type '$type'" ); |
d4b1166e |
708 | } |
709 | |
2120a181 |
710 | sub _apply_digest { |
75be6413 |
711 | my $self = shift; |
2120a181 |
712 | return $self->{digest}->(@_); |
713 | } |
16d1ad9b |
714 | |
2120a181 |
715 | sub _add_free_blist_sector { shift->_add_free_sector( 0, @_ ) } |
716 | sub _add_free_data_sector { shift->_add_free_sector( 1, @_ ) } |
717 | sub _add_free_index_sector { shift->_add_free_sector( 2, @_ ) } |
75be6413 |
718 | |
2120a181 |
719 | sub _add_free_sector { |
720 | my $self = shift; |
721 | my ($multiple, $offset, $size) = @_; |
75be6413 |
722 | |
2120a181 |
723 | my $chains_offset = $multiple * $self->byte_size; |
75be6413 |
724 | |
2120a181 |
725 | my $storage = $self->storage; |
75be6413 |
726 | |
2120a181 |
727 | # Increment staleness. |
728 | # XXX Can this increment+modulo be done by "&= 0x1" ? |
e9b0b5f0 |
729 | my $staleness = unpack( $StP{$STALE_SIZE}, $storage->read_at( $offset + SIG_SIZE, $STALE_SIZE ) ); |
730 | $staleness = ($staleness + 1 ) % ( 2 ** ( 8 * $STALE_SIZE ) ); |
731 | $storage->print_at( $offset + SIG_SIZE, pack( $StP{$STALE_SIZE}, $staleness ) ); |
75be6413 |
732 | |
2120a181 |
733 | my $old_head = $storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
75be6413 |
734 | |
2120a181 |
735 | $storage->print_at( $self->chains_loc + $chains_offset, |
736 | pack( $StP{$self->byte_size}, $offset ), |
737 | ); |
75be6413 |
738 | |
2120a181 |
739 | # Record the old head in the new sector after the signature and staleness counter |
e9b0b5f0 |
740 | $storage->print_at( $offset + SIG_SIZE + $STALE_SIZE, $old_head ); |
2120a181 |
741 | } |
75be6413 |
742 | |
2120a181 |
743 | sub _request_blist_sector { shift->_request_sector( 0, @_ ) } |
744 | sub _request_data_sector { shift->_request_sector( 1, @_ ) } |
745 | sub _request_index_sector { shift->_request_sector( 2, @_ ) } |
7b1e1aa1 |
746 | |
2120a181 |
747 | sub _request_sector { |
748 | my $self = shift; |
749 | my ($multiple, $size) = @_; |
75be6413 |
750 | |
2120a181 |
751 | my $chains_offset = $multiple * $self->byte_size; |
2603d86e |
752 | |
2120a181 |
753 | my $old_head = $self->storage->read_at( $self->chains_loc + $chains_offset, $self->byte_size ); |
754 | my $loc = unpack( $StP{$self->byte_size}, $old_head ); |
75be6413 |
755 | |
2120a181 |
756 | # We don't have any free sectors of the right size, so allocate a new one. |
757 | unless ( $loc ) { |
758 | my $offset = $self->storage->request_space( $size ); |
7b1e1aa1 |
759 | |
2120a181 |
760 | # Zero out the new sector. This also guarantees correct increases |
761 | # in the filesize. |
762 | $self->storage->print_at( $offset, chr(0) x $size ); |
7b1e1aa1 |
763 | |
2120a181 |
764 | return $offset; |
7b1e1aa1 |
765 | } |
766 | |
2120a181 |
767 | # Read the new head after the signature and the staleness counter |
e9b0b5f0 |
768 | my $new_head = $self->storage->read_at( $loc + SIG_SIZE + $STALE_SIZE, $self->byte_size ); |
2120a181 |
769 | $self->storage->print_at( $self->chains_loc + $chains_offset, $new_head ); |
770 | $self->storage->print_at( |
e9b0b5f0 |
771 | $loc + SIG_SIZE + $STALE_SIZE, |
2120a181 |
772 | pack( $StP{$self->byte_size}, 0 ), |
7b1e1aa1 |
773 | ); |
75be6413 |
774 | |
2120a181 |
775 | return $loc; |
75be6413 |
776 | } |
777 | |
2120a181 |
778 | ################################################################################ |
8db25060 |
779 | |
2120a181 |
780 | sub storage { $_[0]{storage} } |
781 | sub byte_size { $_[0]{byte_size} } |
782 | sub hash_size { $_[0]{hash_size} } |
783 | sub hash_chars { $_[0]{hash_chars} } |
784 | sub num_txns { $_[0]{num_txns} } |
785 | sub max_buckets { $_[0]{max_buckets} } |
786 | sub blank_md5 { chr(0) x $_[0]->hash_size } |
e9b0b5f0 |
787 | sub data_sector_size { $_[0]{data_sector_size} } |
788 | |
789 | # This is a calculated value |
790 | sub txn_bitfield_len { |
791 | my $self = shift; |
792 | unless ( exists $self->{txn_bitfield_len} ) { |
793 | my $temp = ($self->num_txns) / 8; |
794 | if ( $temp > int( $temp ) ) { |
795 | $temp = int( $temp ) + 1; |
796 | } |
797 | $self->{txn_bitfield_len} = $temp; |
798 | } |
799 | return $self->{txn_bitfield_len}; |
800 | } |
8db25060 |
801 | |
2120a181 |
802 | sub trans_id { $_[0]{trans_id} } |
803 | sub set_trans_id { $_[0]{trans_id} = $_[1] } |
8db25060 |
804 | |
2120a181 |
805 | sub trans_loc { $_[0]{trans_loc} } |
806 | sub set_trans_loc { $_[0]{trans_loc} = $_[1] } |
807 | |
808 | sub chains_loc { $_[0]{chains_loc} } |
809 | sub set_chains_loc { $_[0]{chains_loc} = $_[1] } |
810 | |
811 | ################################################################################ |
812 | |
813 | package DBM::Deep::Iterator; |
814 | |
815 | sub new { |
816 | my $class = shift; |
817 | my ($args) = @_; |
818 | |
819 | my $self = bless { |
820 | breadcrumbs => [], |
821 | engine => $args->{engine}, |
822 | base_offset => $args->{base_offset}, |
823 | }, $class; |
824 | |
825 | Scalar::Util::weaken( $self->{engine} ); |
826 | |
827 | return $self; |
828 | } |
829 | |
830 | sub reset { $_[0]{breadcrumbs} = [] } |
831 | |
832 | sub get_sector_iterator { |
833 | my $self = shift; |
834 | my ($loc) = @_; |
835 | |
836 | my $sector = $self->{engine}->_load_sector( $loc ) |
837 | or return; |
838 | |
839 | if ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
840 | return DBM::Deep::Iterator::Index->new({ |
841 | iterator => $self, |
842 | sector => $sector, |
685e40f1 |
843 | }); |
2120a181 |
844 | } |
845 | elsif ( $sector->isa( 'DBM::Deep::Engine::Sector::BucketList' ) ) { |
846 | return DBM::Deep::Iterator::BucketList->new({ |
847 | iterator => $self, |
848 | sector => $sector, |
849 | }); |
850 | } |
8db25060 |
851 | |
2120a181 |
852 | DBM::Deep->_throw_error( "get_sector_iterator(): Why did $loc make a $sector?" ); |
853 | } |
854 | |
855 | sub get_next_key { |
856 | my $self = shift; |
857 | my ($obj) = @_; |
858 | |
859 | my $crumbs = $self->{breadcrumbs}; |
860 | my $e = $self->{engine}; |
861 | |
862 | unless ( @$crumbs ) { |
863 | # This will be a Reference sector |
864 | my $sector = $e->_load_sector( $self->{base_offset} ) |
865 | # If no sector is found, thist must have been deleted from under us. |
866 | or return; |
867 | |
868 | if ( $sector->staleness != $obj->_staleness ) { |
869 | return; |
8db25060 |
870 | } |
871 | |
2120a181 |
872 | my $loc = $sector->get_blist_loc |
873 | or return; |
874 | |
875 | push @$crumbs, $self->get_sector_iterator( $loc ); |
8db25060 |
876 | } |
8db25060 |
877 | |
2120a181 |
878 | FIND_NEXT_KEY: { |
879 | # We're at the end. |
880 | unless ( @$crumbs ) { |
881 | $self->reset; |
8db25060 |
882 | return; |
883 | } |
8db25060 |
884 | |
2120a181 |
885 | my $iterator = $crumbs->[-1]; |
886 | |
887 | # This level is done. |
888 | if ( $iterator->at_end ) { |
889 | pop @$crumbs; |
890 | redo FIND_NEXT_KEY; |
891 | } |
892 | |
893 | if ( $iterator->isa( 'DBM::Deep::Iterator::Index' ) ) { |
894 | # If we don't have any more, it will be caught at the |
895 | # prior check. |
896 | if ( my $next = $iterator->get_next_iterator ) { |
897 | push @$crumbs, $next; |
898 | } |
899 | redo FIND_NEXT_KEY; |
900 | } |
901 | |
902 | unless ( $iterator->isa( 'DBM::Deep::Iterator::BucketList' ) ) { |
903 | DBM::Deep->_throw_error( |
904 | "Should have a bucketlist iterator here - instead have $iterator" |
905 | ); |
906 | } |
907 | |
908 | # At this point, we have a BucketList iterator |
909 | my $key = $iterator->get_next_key; |
910 | if ( defined $key ) { |
911 | return $key; |
912 | } |
913 | #XXX else { $iterator->set_to_end() } ? |
914 | |
915 | # We hit the end of the bucketlist iterator, so redo |
916 | redo FIND_NEXT_KEY; |
8db25060 |
917 | } |
918 | |
2120a181 |
919 | DBM::Deep->_throw_error( "get_next_key(): How did we get here?" ); |
8db25060 |
920 | } |
921 | |
2120a181 |
922 | package DBM::Deep::Iterator::Index; |
923 | |
924 | sub new { |
925 | my $self = bless $_[1] => $_[0]; |
926 | $self->{curr_index} = 0; |
927 | return $self; |
928 | } |
929 | |
930 | sub at_end { |
beac1dff |
931 | my $self = shift; |
2120a181 |
932 | return $self->{curr_index} >= $self->{iterator}{engine}->hash_chars; |
933 | } |
9020ee8c |
934 | |
2120a181 |
935 | sub get_next_iterator { |
936 | my $self = shift; |
94e8af14 |
937 | |
2120a181 |
938 | my $loc; |
939 | while ( !$loc ) { |
940 | return if $self->at_end; |
941 | $loc = $self->{sector}->get_entry( $self->{curr_index}++ ); |
386bab6c |
942 | } |
94e8af14 |
943 | |
2120a181 |
944 | return $self->{iterator}->get_sector_iterator( $loc ); |
945 | } |
946 | |
947 | package DBM::Deep::Iterator::BucketList; |
948 | |
949 | sub new { |
950 | my $self = bless $_[1] => $_[0]; |
951 | $self->{curr_index} = 0; |
952 | return $self; |
953 | } |
954 | |
955 | sub at_end { |
956 | my $self = shift; |
957 | return $self->{curr_index} >= $self->{iterator}{engine}->max_buckets; |
958 | } |
959 | |
960 | sub get_next_key { |
961 | my $self = shift; |
962 | |
963 | return if $self->at_end; |
964 | |
965 | my $idx = $self->{curr_index}++; |
966 | |
967 | my $data_loc = $self->{sector}->get_data_location_for({ |
968 | allow_head => 1, |
969 | idx => $idx, |
970 | }) or return; |
971 | |
972 | #XXX Do we want to add corruption checks here? |
973 | return $self->{sector}->get_key_for( $idx )->data; |
974 | } |
975 | |
976 | package DBM::Deep::Engine::Sector; |
977 | |
978 | sub new { |
979 | my $self = bless $_[1], $_[0]; |
980 | Scalar::Util::weaken( $self->{engine} ); |
981 | $self->_init; |
982 | return $self; |
983 | } |
984 | |
985 | #sub _init {} |
986 | #sub clone { DBM::Deep->_throw_error( "Must be implemented in the child class" ); } |
987 | |
988 | sub engine { $_[0]{engine} } |
989 | sub offset { $_[0]{offset} } |
990 | sub type { $_[0]{type} } |
991 | |
992 | sub base_size { |
993 | my $self = shift; |
e9b0b5f0 |
994 | return $self->engine->SIG_SIZE + $STALE_SIZE; |
2120a181 |
995 | } |
996 | |
997 | sub free { |
998 | my $self = shift; |
999 | |
1000 | my $e = $self->engine; |
1001 | |
1002 | $e->storage->print_at( $self->offset, $e->SIG_FREE ); |
1003 | # Skip staleness counter |
1004 | $e->storage->print_at( $self->offset + $self->base_size, |
1005 | chr(0) x ($self->size - $self->base_size), |
1006 | ); |
1007 | |
1008 | my $free_meth = $self->free_meth; |
1009 | $e->$free_meth( $self->offset, $self->size ); |
1010 | |
beac1dff |
1011 | return; |
9020ee8c |
1012 | } |
ab0e4957 |
1013 | |
2120a181 |
1014 | package DBM::Deep::Engine::Sector::Data; |
1015 | |
1016 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1017 | |
1018 | # This is in bytes |
e9b0b5f0 |
1019 | sub size { $_[0]{engine}->data_sector_size } |
2120a181 |
1020 | sub free_meth { return '_add_free_data_sector' } |
1021 | |
1022 | sub clone { |
beac1dff |
1023 | my $self = shift; |
2120a181 |
1024 | return ref($self)->new({ |
1025 | engine => $self->engine, |
2120a181 |
1026 | type => $self->type, |
e9b0b5f0 |
1027 | data => $self->data, |
2120a181 |
1028 | }); |
1029 | } |
1030 | |
1031 | package DBM::Deep::Engine::Sector::Scalar; |
1032 | |
1033 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
ab0e4957 |
1034 | |
2120a181 |
1035 | sub free { |
1036 | my $self = shift; |
633df1fd |
1037 | |
2120a181 |
1038 | my $chain_loc = $self->chain_loc; |
633df1fd |
1039 | |
2120a181 |
1040 | $self->SUPER::free(); |
633df1fd |
1041 | |
2120a181 |
1042 | if ( $chain_loc ) { |
1043 | $self->engine->_load_sector( $chain_loc )->free; |
633df1fd |
1044 | } |
1045 | |
2120a181 |
1046 | return; |
1047 | } |
1048 | |
1049 | sub type { $_[0]{engine}->SIG_DATA } |
1050 | sub _init { |
1051 | my $self = shift; |
1052 | |
1053 | my $engine = $self->engine; |
1054 | |
1055 | unless ( $self->offset ) { |
e9b0b5f0 |
1056 | my $data_section = $self->size - $self->base_size - $engine->byte_size - 1; |
7a960a12 |
1057 | |
2120a181 |
1058 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
7a960a12 |
1059 | |
2120a181 |
1060 | my $data = delete $self->{data}; |
1061 | my $dlen = length $data; |
1062 | my $continue = 1; |
1063 | my $curr_offset = $self->offset; |
1064 | while ( $continue ) { |
633df1fd |
1065 | |
2120a181 |
1066 | my $next_offset = 0; |
1067 | |
1068 | my ($leftover, $this_len, $chunk); |
1069 | if ( $dlen > $data_section ) { |
1070 | $leftover = 0; |
1071 | $this_len = $data_section; |
1072 | $chunk = substr( $data, 0, $this_len ); |
1073 | |
1074 | $dlen -= $data_section; |
1075 | $next_offset = $engine->_request_data_sector( $self->size ); |
1076 | $data = substr( $data, $this_len ); |
1077 | } |
1078 | else { |
1079 | $leftover = $data_section - $dlen; |
1080 | $this_len = $dlen; |
1081 | $chunk = $data; |
ea2f6d67 |
1082 | |
2120a181 |
1083 | $continue = 0; |
ea2f6d67 |
1084 | } |
2120a181 |
1085 | |
1086 | $engine->storage->print_at( $curr_offset, $self->type ); # Sector type |
1087 | # Skip staleness |
1088 | $engine->storage->print_at( $curr_offset + $self->base_size, |
1089 | pack( $StP{$engine->byte_size}, $next_offset ), # Chain loc |
1090 | pack( $StP{1}, $this_len ), # Data length |
1091 | $chunk, # Data to be stored in this sector |
1092 | chr(0) x $leftover, # Zero-fill the rest |
1093 | ); |
1094 | |
1095 | $curr_offset = $next_offset; |
633df1fd |
1096 | } |
1097 | |
2120a181 |
1098 | return; |
386bab6c |
1099 | } |
2120a181 |
1100 | } |
7a960a12 |
1101 | |
2120a181 |
1102 | sub data_length { |
1103 | my $self = shift; |
7a960a12 |
1104 | |
2120a181 |
1105 | my $buffer = $self->engine->storage->read_at( |
1106 | $self->offset + $self->base_size + $self->engine->byte_size, 1 |
1107 | ); |
633df1fd |
1108 | |
2120a181 |
1109 | return unpack( $StP{1}, $buffer ); |
ab0e4957 |
1110 | } |
1111 | |
2120a181 |
1112 | sub chain_loc { |
beac1dff |
1113 | my $self = shift; |
2120a181 |
1114 | return unpack( |
1115 | $StP{$self->engine->byte_size}, |
1116 | $self->engine->storage->read_at( |
1117 | $self->offset + $self->base_size, |
1118 | $self->engine->byte_size, |
1119 | ), |
1120 | ); |
1121 | } |
912d50b1 |
1122 | |
2120a181 |
1123 | sub data { |
1124 | my $self = shift; |
1125 | |
1126 | my $data; |
1127 | while ( 1 ) { |
1128 | my $chain_loc = $self->chain_loc; |
1129 | |
1130 | $data .= $self->engine->storage->read_at( |
1131 | $self->offset + $self->base_size + $self->engine->byte_size + 1, $self->data_length, |
1132 | ); |
1133 | |
1134 | last unless $chain_loc; |
1135 | |
1136 | $self = $self->engine->_load_sector( $chain_loc ); |
ea2f6d67 |
1137 | } |
2120a181 |
1138 | |
1139 | return $data; |
912d50b1 |
1140 | } |
1141 | |
2120a181 |
1142 | package DBM::Deep::Engine::Sector::Null; |
1143 | |
1144 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
1145 | |
1146 | sub type { $_[0]{engine}->SIG_NULL } |
1147 | sub data_length { 0 } |
1148 | sub data { return } |
1149 | |
1150 | sub _init { |
beac1dff |
1151 | my $self = shift; |
d0b74c17 |
1152 | |
2120a181 |
1153 | my $engine = $self->engine; |
d0b74c17 |
1154 | |
2120a181 |
1155 | unless ( $self->offset ) { |
1156 | my $leftover = $self->size - $self->base_size - 1 * $engine->byte_size - 1; |
d0b74c17 |
1157 | |
2120a181 |
1158 | $self->{offset} = $engine->_request_data_sector( $self->size ); |
1159 | $engine->storage->print_at( $self->offset, $self->type ); # Sector type |
1160 | # Skip staleness counter |
1161 | $engine->storage->print_at( $self->offset + $self->base_size, |
1162 | pack( $StP{$engine->byte_size}, 0 ), # Chain loc |
1163 | pack( $StP{1}, $self->data_length ), # Data length |
1164 | chr(0) x $leftover, # Zero-fill the rest |
1165 | ); |
d0b74c17 |
1166 | |
2120a181 |
1167 | return; |
1168 | } |
1169 | } |
d0b74c17 |
1170 | |
2120a181 |
1171 | package DBM::Deep::Engine::Sector::Reference; |
16d1ad9b |
1172 | |
2120a181 |
1173 | our @ISA = qw( DBM::Deep::Engine::Sector::Data ); |
d0b74c17 |
1174 | |
2120a181 |
1175 | sub _init { |
1176 | my $self = shift; |
d5d7c51d |
1177 | |
2120a181 |
1178 | my $e = $self->engine; |
d5d7c51d |
1179 | |
2120a181 |
1180 | unless ( $self->offset ) { |
1181 | my $classname = Scalar::Util::blessed( delete $self->{data} ); |
1182 | my $leftover = $self->size - $self->base_size - 2 * $e->byte_size; |
1183 | |
1184 | my $class_offset = 0; |
1185 | if ( defined $classname ) { |
1186 | my $class_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
1187 | engine => $e, |
1188 | data => $classname, |
1189 | }); |
1190 | $class_offset = $class_sector->offset; |
d0b74c17 |
1191 | } |
1192 | |
2120a181 |
1193 | $self->{offset} = $e->_request_data_sector( $self->size ); |
1194 | $e->storage->print_at( $self->offset, $self->type ); # Sector type |
1195 | # Skip staleness counter |
1196 | $e->storage->print_at( $self->offset + $self->base_size, |
1197 | pack( $StP{$e->byte_size}, 0 ), # Index/BList loc |
1198 | pack( $StP{$e->byte_size}, $class_offset ), # Classname loc |
1199 | chr(0) x $leftover, # Zero-fill the rest |
1200 | ); |
1201 | } |
1202 | else { |
1203 | $self->{type} = $e->storage->read_at( $self->offset, 1 ); |
beac1dff |
1204 | } |
d0b74c17 |
1205 | |
2120a181 |
1206 | $self->{staleness} = unpack( |
e9b0b5f0 |
1207 | $StP{$STALE_SIZE}, |
1208 | $e->storage->read_at( $self->offset + $e->SIG_SIZE, $STALE_SIZE ), |
2120a181 |
1209 | ); |
1210 | |
1211 | return; |
6736c116 |
1212 | } |
1213 | |
2120a181 |
1214 | sub free { |
d0b74c17 |
1215 | my $self = shift; |
d0b74c17 |
1216 | |
2120a181 |
1217 | my $blist_loc = $self->get_blist_loc; |
1218 | $self->engine->_load_sector( $blist_loc )->free if $blist_loc; |
d0b74c17 |
1219 | |
2120a181 |
1220 | my $class_loc = $self->get_class_offset; |
1221 | $self->engine->_load_sector( $class_loc )->free if $class_loc; |
d0b74c17 |
1222 | |
2120a181 |
1223 | $self->SUPER::free(); |
d0b74c17 |
1224 | } |
1225 | |
2120a181 |
1226 | sub staleness { $_[0]{staleness} } |
1227 | |
1228 | sub get_data_for { |
6736c116 |
1229 | my $self = shift; |
2120a181 |
1230 | my ($args) = @_; |
d0b74c17 |
1231 | |
2120a181 |
1232 | # Assume that the head is not allowed unless otherwise specified. |
1233 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
6736c116 |
1234 | |
2120a181 |
1235 | # Assume we don't create a new blist location unless otherwise specified. |
1236 | $args->{create} = 0 unless exists $args->{create}; |
d0b74c17 |
1237 | |
2120a181 |
1238 | my $blist = $self->get_bucket_list({ |
1239 | key_md5 => $args->{key_md5}, |
1240 | key => $args->{key}, |
1241 | create => $args->{create}, |
1242 | }); |
1243 | return unless $blist && $blist->{found}; |
e5fc7e69 |
1244 | |
2120a181 |
1245 | # At this point, $blist knows where the md5 is. What it -doesn't- know yet |
1246 | # is whether or not this transaction has this key. That's part of the next |
1247 | # function call. |
1248 | my $location = $blist->get_data_location_for({ |
1249 | allow_head => $args->{allow_head}, |
1250 | }) or return; |
e5fc7e69 |
1251 | |
2120a181 |
1252 | return $self->engine->_load_sector( $location ); |
1253 | } |
d0b74c17 |
1254 | |
2120a181 |
1255 | sub write_data { |
1256 | my $self = shift; |
1257 | my ($args) = @_; |
1258 | |
1259 | my $blist = $self->get_bucket_list({ |
1260 | key_md5 => $args->{key_md5}, |
1261 | key => $args->{key}, |
1262 | create => 1, |
1263 | }) or DBM::Deep->_throw_error( "How did write_data fail (no blist)?!" ); |
1264 | |
1265 | # Handle any transactional bookkeeping. |
1266 | if ( $self->engine->trans_id ) { |
1267 | if ( ! $blist->has_md5 ) { |
1268 | $blist->mark_deleted({ |
1269 | trans_id => 0, |
1270 | }); |
1271 | } |
42717e46 |
1272 | } |
e5fc7e69 |
1273 | else { |
2120a181 |
1274 | my @trans_ids = $self->engine->get_running_txn_ids; |
1275 | if ( $blist->has_md5 ) { |
1276 | if ( @trans_ids ) { |
1277 | my $old_value = $blist->get_data_for; |
1278 | foreach my $other_trans_id ( @trans_ids ) { |
1279 | next if $blist->get_data_location_for({ |
1280 | trans_id => $other_trans_id, |
1281 | allow_head => 0, |
1282 | }); |
1283 | $blist->write_md5({ |
1284 | trans_id => $other_trans_id, |
1285 | key => $args->{key}, |
1286 | key_md5 => $args->{key_md5}, |
1287 | value => $old_value->clone, |
1288 | }); |
1289 | } |
beac1dff |
1290 | } |
2120a181 |
1291 | } |
1292 | else { |
1293 | if ( @trans_ids ) { |
1294 | foreach my $other_trans_id ( @trans_ids ) { |
1295 | #XXX This doesn't seem to possible to ever happen . . . |
1296 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1297 | $blist->mark_deleted({ |
1298 | trans_id => $other_trans_id, |
1299 | }); |
ea2f6d67 |
1300 | } |
2120a181 |
1301 | } |
1302 | } |
1303 | } |
ea2f6d67 |
1304 | |
2120a181 |
1305 | #XXX Is this safe to do transactionally? |
1306 | # Free the place we're about to write to. |
1307 | if ( $blist->get_data_location_for({ allow_head => 0 }) ) { |
1308 | $blist->get_data_for({ allow_head => 0 })->free; |
1309 | } |
8db25060 |
1310 | |
2120a181 |
1311 | $blist->write_md5({ |
1312 | key => $args->{key}, |
1313 | key_md5 => $args->{key_md5}, |
1314 | value => $args->{value}, |
1315 | }); |
1316 | } |
d0b74c17 |
1317 | |
2120a181 |
1318 | sub delete_key { |
1319 | my $self = shift; |
1320 | my ($args) = @_; |
86867f3a |
1321 | |
2120a181 |
1322 | # XXX What should happen if this fails? |
1323 | my $blist = $self->get_bucket_list({ |
1324 | key_md5 => $args->{key_md5}, |
1325 | }) or DBM::Deep->_throw_error( "How did delete_key fail (no blist)?!" ); |
1326 | |
1327 | # Save the location so that we can free the data |
1328 | my $location = $blist->get_data_location_for({ |
1329 | allow_head => 0, |
1330 | }); |
1331 | my $old_value = $location && $self->engine->_load_sector( $location ); |
1332 | |
1333 | my @trans_ids = $self->engine->get_running_txn_ids; |
1334 | |
1335 | if ( $self->engine->trans_id == 0 ) { |
1336 | if ( @trans_ids ) { |
1337 | foreach my $other_trans_id ( @trans_ids ) { |
1338 | next if $blist->get_data_location_for({ trans_id => $other_trans_id, allow_head => 0 }); |
1339 | $blist->write_md5({ |
1340 | trans_id => $other_trans_id, |
1341 | key => $args->{key}, |
1342 | key_md5 => $args->{key_md5}, |
1343 | value => $old_value->clone, |
1344 | }); |
beac1dff |
1345 | } |
8db25060 |
1346 | } |
2120a181 |
1347 | } |
d0b74c17 |
1348 | |
2120a181 |
1349 | my $data; |
1350 | if ( @trans_ids ) { |
1351 | $blist->mark_deleted( $args ); |
1352 | |
1353 | if ( $old_value ) { |
1354 | $data = $old_value->data; |
1355 | $old_value->free; |
1356 | } |
1357 | } |
1358 | else { |
1359 | $data = $blist->delete_md5( $args ); |
42717e46 |
1360 | } |
d0b74c17 |
1361 | |
2120a181 |
1362 | return $data; |
6736c116 |
1363 | } |
1364 | |
2120a181 |
1365 | sub get_blist_loc { |
1366 | my $self = shift; |
75be6413 |
1367 | |
2120a181 |
1368 | my $e = $self->engine; |
1369 | my $blist_loc = $e->storage->read_at( $self->offset + $self->base_size, $e->byte_size ); |
1370 | return unpack( $StP{$e->byte_size}, $blist_loc ); |
1371 | } |
1372 | |
1373 | sub get_bucket_list { |
75be6413 |
1374 | my $self = shift; |
2120a181 |
1375 | my ($args) = @_; |
1376 | $args ||= {}; |
1377 | |
1378 | # XXX Add in check here for recycling? |
1379 | |
1380 | my $engine = $self->engine; |
1381 | |
1382 | my $blist_loc = $self->get_blist_loc; |
1383 | |
1384 | # There's no index or blist yet |
1385 | unless ( $blist_loc ) { |
1386 | return unless $args->{create}; |
1387 | |
1388 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
1389 | engine => $engine, |
1390 | key_md5 => $args->{key_md5}, |
1391 | }); |
1392 | |
1393 | $engine->storage->print_at( $self->offset + $self->base_size, |
1394 | pack( $StP{$engine->byte_size}, $blist->offset ), |
1395 | ); |
1396 | |
1397 | return $blist; |
1398 | } |
1399 | |
1400 | my $sector = $engine->_load_sector( $blist_loc ) |
1401 | or DBM::Deep->_throw_error( "Cannot read sector at $blist_loc in get_bucket_list()" ); |
1402 | my $i = 0; |
1403 | my $last_sector = undef; |
1404 | while ( $sector->isa( 'DBM::Deep::Engine::Sector::Index' ) ) { |
1405 | $blist_loc = $sector->get_entry( ord( substr( $args->{key_md5}, $i++, 1 ) ) ); |
1406 | $last_sector = $sector; |
1407 | if ( $blist_loc ) { |
1408 | $sector = $engine->_load_sector( $blist_loc ) |
1409 | or DBM::Deep->_throw_error( "Cannot read sector at $blist_loc in get_bucket_list()" ); |
1410 | } |
1411 | else { |
1412 | $sector = undef; |
1413 | last; |
1414 | } |
1415 | } |
1416 | |
1417 | # This means we went through the Index sector(s) and found an empty slot |
1418 | unless ( $sector ) { |
1419 | return unless $args->{create}; |
1420 | |
1421 | DBM::Deep->_throw_error( "No last_sector when attempting to build a new entry" ) |
1422 | unless $last_sector; |
1423 | |
1424 | my $blist = DBM::Deep::Engine::Sector::BucketList->new({ |
1425 | engine => $engine, |
1426 | key_md5 => $args->{key_md5}, |
1427 | }); |
1428 | |
1429 | $last_sector->set_entry( ord( substr( $args->{key_md5}, $i - 1, 1 ) ) => $blist->offset ); |
1430 | |
1431 | return $blist; |
1432 | } |
75be6413 |
1433 | |
2120a181 |
1434 | $sector->find_md5( $args->{key_md5} ); |
1435 | |
1436 | # See whether or not we need to reindex the bucketlist |
1437 | if ( !$sector->has_md5 && $args->{create} && $sector->{idx} == -1 ) { |
1438 | my $new_index = DBM::Deep::Engine::Sector::Index->new({ |
1439 | engine => $engine, |
1440 | }); |
1441 | |
1442 | my %blist_cache; |
1443 | #XXX q.v. the comments for this function. |
1444 | foreach my $entry ( $sector->chopped_up ) { |
1445 | my ($spot, $md5) = @{$entry}; |
1446 | my $idx = ord( substr( $md5, $i, 1 ) ); |
1447 | |
1448 | # XXX This is inefficient |
1449 | my $blist = $blist_cache{$idx} |
1450 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1451 | engine => $engine, |
1452 | }); |
1453 | |
1454 | $new_index->set_entry( $idx => $blist->offset ); |
1455 | |
1456 | my $new_spot = $blist->write_at_next_open( $md5 ); |
1457 | $engine->reindex_entry( $spot => $new_spot ); |
1458 | } |
1459 | |
1460 | # Handle the new item separately. |
1461 | { |
1462 | my $idx = ord( substr( $args->{key_md5}, $i, 1 ) ); |
1463 | my $blist = $blist_cache{$idx} |
1464 | ||= DBM::Deep::Engine::Sector::BucketList->new({ |
1465 | engine => $engine, |
1466 | }); |
1467 | |
1468 | $new_index->set_entry( $idx => $blist->offset ); |
1469 | |
1470 | #XXX THIS IS HACKY! |
1471 | $blist->find_md5( $args->{key_md5} ); |
1472 | $blist->write_md5({ |
1473 | key => $args->{key}, |
1474 | key_md5 => $args->{key_md5}, |
1475 | value => DBM::Deep::Engine::Sector::Null->new({ |
1476 | engine => $engine, |
1477 | data => undef, |
1478 | }), |
1479 | }); |
1480 | } |
1481 | |
1482 | if ( $last_sector ) { |
1483 | $last_sector->set_entry( |
1484 | ord( substr( $args->{key_md5}, $i - 1, 1 ) ), |
1485 | $new_index->offset, |
1486 | ); |
1487 | } else { |
1488 | $engine->storage->print_at( $self->offset + $self->base_size, |
1489 | pack( $StP{$engine->byte_size}, $new_index->offset ), |
1490 | ); |
1491 | } |
1492 | |
1493 | $sector->free; |
1494 | |
1495 | $sector = $blist_cache{ ord( substr( $args->{key_md5}, $i, 1 ) ) }; |
1496 | $sector->find_md5( $args->{key_md5} ); |
1497 | } |
1498 | |
1499 | return $sector; |
1500 | } |
1501 | |
1502 | sub get_class_offset { |
1503 | my $self = shift; |
1504 | |
1505 | my $e = $self->engine; |
ea2f6d67 |
1506 | return unpack( |
2120a181 |
1507 | $StP{$e->byte_size}, |
1508 | $e->storage->read_at( |
1509 | $self->offset + $self->base_size + 1 * $e->byte_size, $e->byte_size, |
75be6413 |
1510 | ), |
1511 | ); |
75be6413 |
1512 | } |
1513 | |
2120a181 |
1514 | sub get_classname { |
d608b06e |
1515 | my $self = shift; |
21838116 |
1516 | |
2120a181 |
1517 | my $class_offset = $self->get_class_offset; |
1518 | |
1519 | return unless $class_offset; |
1520 | |
1521 | return $self->engine->_load_sector( $class_offset )->data; |
1522 | } |
1523 | |
1524 | #XXX Add singleton handling here |
1525 | sub data { |
1526 | my $self = shift; |
1527 | |
1528 | my $new_obj = DBM::Deep->new({ |
1529 | type => $self->type, |
1530 | base_offset => $self->offset, |
1531 | staleness => $self->staleness, |
1532 | storage => $self->engine->storage, |
1533 | engine => $self->engine, |
1534 | }); |
1535 | |
1536 | if ( $self->engine->storage->{autobless} ) { |
1537 | my $classname = $self->get_classname; |
1538 | if ( defined $classname ) { |
1539 | bless $new_obj, $classname; |
1540 | } |
1541 | } |
1542 | |
1543 | return $new_obj; |
1544 | } |
1545 | |
1546 | package DBM::Deep::Engine::Sector::BucketList; |
1547 | |
1548 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1549 | |
1550 | sub _init { |
1551 | my $self = shift; |
1552 | |
1553 | my $engine = $self->engine; |
1554 | |
1555 | unless ( $self->offset ) { |
1556 | my $leftover = $self->size - $self->base_size; |
1557 | |
1558 | $self->{offset} = $engine->_request_blist_sector( $self->size ); |
1559 | $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type |
1560 | # Skip staleness counter |
1561 | $engine->storage->print_at( $self->offset + $self->base_size, |
1562 | chr(0) x $leftover, # Zero-fill the data |
9a187d8c |
1563 | ); |
2120a181 |
1564 | } |
d608b06e |
1565 | |
2120a181 |
1566 | if ( $self->{key_md5} ) { |
1567 | $self->find_md5; |
d608b06e |
1568 | } |
1569 | |
2120a181 |
1570 | return $self; |
d608b06e |
1571 | } |
1572 | |
2120a181 |
1573 | sub size { |
994ccd8e |
1574 | my $self = shift; |
2120a181 |
1575 | unless ( $self->{size} ) { |
1576 | my $e = $self->engine; |
1577 | # Base + numbuckets * bucketsize |
1578 | $self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size; |
1579 | } |
1580 | return $self->{size}; |
1581 | } |
994ccd8e |
1582 | |
2120a181 |
1583 | sub free_meth { return '_add_free_blist_sector' } |
7b1e1aa1 |
1584 | |
2120a181 |
1585 | sub bucket_size { |
1586 | my $self = shift; |
1587 | unless ( $self->{bucket_size} ) { |
1588 | my $e = $self->engine; |
1589 | # Key + head (location) + transactions (location + staleness-counter) |
e9b0b5f0 |
1590 | my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $STALE_SIZE); |
2120a181 |
1591 | $self->{bucket_size} = $e->hash_size + $location_size; |
1592 | } |
1593 | return $self->{bucket_size}; |
1594 | } |
7b1e1aa1 |
1595 | |
2120a181 |
1596 | # XXX This is such a poor hack. I need to rethink this code. |
1597 | sub chopped_up { |
1598 | my $self = shift; |
1599 | |
1600 | my $e = $self->engine; |
1601 | |
1602 | my @buckets; |
1603 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
1604 | my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size; |
1605 | my $md5 = $e->storage->read_at( $spot, $e->hash_size ); |
1606 | |
1607 | #XXX If we're chopping, why would we ever have the blank_md5? |
1608 | last if $md5 eq $e->blank_md5; |
1609 | |
1610 | my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size ); |
1611 | push @buckets, [ $spot, $md5 . $rest ]; |
1612 | } |
1613 | |
1614 | return @buckets; |
994ccd8e |
1615 | } |
1616 | |
2120a181 |
1617 | sub write_at_next_open { |
1618 | my $self = shift; |
1619 | my ($entry) = @_; |
1620 | |
1621 | #XXX This is such a hack! |
1622 | $self->{_next_open} = 0 unless exists $self->{_next_open}; |
1623 | |
1624 | my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size; |
1625 | $self->engine->storage->print_at( $spot, $entry ); |
1626 | |
1627 | return $spot; |
e96daec8 |
1628 | } |
1629 | |
2120a181 |
1630 | sub has_md5 { |
1631 | my $self = shift; |
1632 | unless ( exists $self->{found} ) { |
1633 | $self->find_md5; |
1634 | } |
1635 | return $self->{found}; |
1636 | } |
86867f3a |
1637 | |
2120a181 |
1638 | sub find_md5 { |
1639 | my $self = shift; |
1640 | |
1641 | $self->{found} = undef; |
1642 | $self->{idx} = -1; |
1643 | |
1644 | if ( @_ ) { |
1645 | $self->{key_md5} = shift; |
1646 | } |
1647 | |
1648 | # If we don't have an MD5, then what are we supposed to do? |
1649 | unless ( exists $self->{key_md5} ) { |
1650 | DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" ); |
1651 | } |
1652 | |
1653 | my $e = $self->engine; |
1654 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
1655 | my $potential = $e->storage->read_at( |
1656 | $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size, |
1657 | ); |
1658 | |
1659 | if ( $potential eq $e->blank_md5 ) { |
1660 | $self->{idx} = $idx; |
86867f3a |
1661 | return; |
2120a181 |
1662 | } |
1663 | |
1664 | if ( $potential eq $self->{key_md5} ) { |
1665 | $self->{found} = 1; |
1666 | $self->{idx} = $idx; |
86867f3a |
1667 | return; |
2120a181 |
1668 | } |
86867f3a |
1669 | } |
1670 | |
1671 | return; |
1672 | } |
1673 | |
2120a181 |
1674 | sub write_md5 { |
86867f3a |
1675 | my $self = shift; |
2120a181 |
1676 | my ($args) = @_; |
1677 | |
1678 | DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key}; |
1679 | DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5}; |
1680 | DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value}; |
86867f3a |
1681 | |
2120a181 |
1682 | my $engine = $self->engine; |
86867f3a |
1683 | |
2120a181 |
1684 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
86867f3a |
1685 | |
2120a181 |
1686 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
1687 | $engine->add_entry( $args->{trans_id}, $spot ); |
1688 | |
1689 | unless ($self->{found}) { |
1690 | my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
1691 | engine => $engine, |
1692 | data => $args->{key}, |
1693 | }); |
1694 | |
1695 | $engine->storage->print_at( $spot, |
1696 | $args->{key_md5}, |
1697 | pack( $StP{$engine->byte_size}, $key_sector->offset ), |
1698 | ); |
86867f3a |
1699 | } |
1700 | |
2120a181 |
1701 | my $loc = $spot |
1702 | + $engine->hash_size |
e9b0b5f0 |
1703 | + $engine->byte_size; |
2120a181 |
1704 | |
e9b0b5f0 |
1705 | if ( $args->{trans_id} ) { |
1706 | $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE ); |
1707 | |
1708 | $engine->storage->print_at( $loc, |
1709 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
1710 | pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
1711 | ); |
1712 | } |
1713 | else { |
1714 | $engine->storage->print_at( $loc, |
1715 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
1716 | ); |
1717 | } |
2120a181 |
1718 | } |
1719 | |
1720 | sub mark_deleted { |
1721 | my $self = shift; |
1722 | my ($args) = @_; |
1723 | $args ||= {}; |
1724 | |
1725 | my $engine = $self->engine; |
1726 | |
1727 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
1728 | |
1729 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
1730 | $engine->add_entry( $args->{trans_id}, $spot ); |
1731 | |
1732 | my $loc = $spot |
1733 | + $engine->hash_size |
e9b0b5f0 |
1734 | + $engine->byte_size; |
1735 | |
1736 | if ( $args->{trans_id} ) { |
1737 | $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE ); |
1738 | |
1739 | $engine->storage->print_at( $loc, |
1740 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
1741 | pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
1742 | ); |
1743 | } |
1744 | else { |
1745 | $engine->storage->print_at( $loc, |
1746 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
1747 | ); |
1748 | } |
2120a181 |
1749 | |
2120a181 |
1750 | } |
1751 | |
1752 | sub delete_md5 { |
1753 | my $self = shift; |
1754 | my ($args) = @_; |
1755 | |
1756 | my $engine = $self->engine; |
1757 | return undef unless $self->{found}; |
1758 | |
1759 | # Save the location so that we can free the data |
1760 | my $location = $self->get_data_location_for({ |
1761 | allow_head => 0, |
1762 | }); |
1763 | my $key_sector = $self->get_key_for; |
1764 | |
1765 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
1766 | $engine->storage->print_at( $spot, |
1767 | $engine->storage->read_at( |
1768 | $spot + $self->bucket_size, |
1769 | $self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ), |
1770 | ), |
1771 | chr(0) x $self->bucket_size, |
1772 | ); |
1773 | |
1774 | $key_sector->free; |
1775 | |
1776 | my $data_sector = $self->engine->_load_sector( $location ); |
1777 | my $data = $data_sector->data; |
1778 | $data_sector->free; |
1779 | |
1780 | return $data; |
1781 | } |
1782 | |
1783 | sub get_data_location_for { |
1784 | my $self = shift; |
1785 | my ($args) = @_; |
1786 | $args ||= {}; |
1787 | |
1788 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
1789 | $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id}; |
1790 | $args->{idx} = $self->{idx} unless exists $args->{idx}; |
1791 | |
1792 | my $e = $self->engine; |
1793 | |
1794 | my $spot = $self->offset + $self->base_size |
1795 | + $args->{idx} * $self->bucket_size |
1796 | + $e->hash_size |
e9b0b5f0 |
1797 | + $e->byte_size; |
1798 | |
1799 | if ( $args->{trans_id} ) { |
1800 | $spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $STALE_SIZE ); |
1801 | } |
2120a181 |
1802 | |
1803 | my $buffer = $e->storage->read_at( |
1804 | $spot, |
e9b0b5f0 |
1805 | $e->byte_size + $STALE_SIZE, |
2120a181 |
1806 | ); |
e9b0b5f0 |
1807 | my ($loc, $staleness) = unpack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, $buffer ); |
1808 | |
1809 | if ( $args->{trans_id} ) { |
1810 | # We have found an entry that is old, so get rid of it |
1811 | if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) { |
1812 | $e->storage->print_at( |
1813 | $spot, |
1814 | pack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, (0) x 2 ), |
1815 | ); |
1816 | $loc = 0; |
1817 | } |
86867f3a |
1818 | } |
1819 | |
2120a181 |
1820 | # If we're in a transaction and we never wrote to this location, try the |
1821 | # HEAD instead. |
1822 | if ( $args->{trans_id} && !$loc && $args->{allow_head} ) { |
1823 | return $self->get_data_location_for({ |
1824 | trans_id => 0, |
1825 | allow_head => 1, |
1826 | idx => $args->{idx}, |
1827 | }); |
1828 | } |
1829 | return $loc <= 1 ? 0 : $loc; |
1830 | } |
1831 | |
1832 | sub get_data_for { |
1833 | my $self = shift; |
1834 | my ($args) = @_; |
1835 | $args ||= {}; |
1836 | |
1837 | return unless $self->{found}; |
1838 | my $location = $self->get_data_location_for({ |
1839 | allow_head => $args->{allow_head}, |
1840 | }); |
1841 | return $self->engine->_load_sector( $location ); |
1842 | } |
1843 | |
1844 | sub get_key_for { |
1845 | my $self = shift; |
1846 | my ($idx) = @_; |
1847 | $idx = $self->{idx} unless defined $idx; |
1848 | |
1849 | if ( $idx >= $self->engine->max_buckets ) { |
1850 | DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" ); |
86867f3a |
1851 | } |
1852 | |
2120a181 |
1853 | my $location = $self->engine->storage->read_at( |
1854 | $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size, |
1855 | $self->engine->byte_size, |
1856 | ); |
1857 | $location = unpack( $StP{$self->engine->byte_size}, $location ); |
1858 | DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location; |
1859 | |
1860 | return $self->engine->_load_sector( $location ); |
1861 | } |
86867f3a |
1862 | |
2120a181 |
1863 | package DBM::Deep::Engine::Sector::Index; |
1864 | |
1865 | our @ISA = qw( DBM::Deep::Engine::Sector ); |
1866 | |
1867 | sub _init { |
1868 | my $self = shift; |
1869 | |
1870 | my $engine = $self->engine; |
1871 | |
1872 | unless ( $self->offset ) { |
1873 | my $leftover = $self->size - $self->base_size; |
1874 | |
1875 | $self->{offset} = $engine->_request_index_sector( $self->size ); |
1876 | $engine->storage->print_at( $self->offset, $engine->SIG_INDEX ); # Sector type |
1877 | # Skip staleness counter |
1878 | $engine->storage->print_at( $self->offset + $self->base_size, |
1879 | chr(0) x $leftover, # Zero-fill the rest |
1880 | ); |
1881 | } |
1882 | |
1883 | return $self; |
1884 | } |
1885 | |
e9b0b5f0 |
1886 | #XXX Change here |
2120a181 |
1887 | sub size { |
1888 | my $self = shift; |
1889 | unless ( $self->{size} ) { |
1890 | my $e = $self->engine; |
1891 | $self->{size} = $self->base_size + $e->byte_size * $e->hash_chars; |
1892 | } |
1893 | return $self->{size}; |
1894 | } |
1895 | |
1896 | sub free_meth { return '_add_free_index_sector' } |
1897 | |
1898 | sub free { |
1899 | my $self = shift; |
1900 | my $e = $self->engine; |
1901 | |
1902 | for my $i ( 0 .. $e->hash_chars - 1 ) { |
1903 | my $l = $self->get_entry( $i ) or next; |
1904 | $e->_load_sector( $l )->free; |
86867f3a |
1905 | } |
1906 | |
2120a181 |
1907 | $self->SUPER::free(); |
1908 | } |
1909 | |
1910 | sub _loc_for { |
1911 | my $self = shift; |
1912 | my ($idx) = @_; |
1913 | return $self->offset + $self->base_size + $idx * $self->engine->byte_size; |
1914 | } |
1915 | |
1916 | sub get_entry { |
1917 | my $self = shift; |
1918 | my ($idx) = @_; |
1919 | |
1920 | my $e = $self->engine; |
1921 | |
1922 | DBM::Deep->_throw_error( "get_entry: Out of range ($idx)" ) |
1923 | if $idx < 0 || $idx >= $e->hash_chars; |
1924 | |
1925 | return unpack( |
1926 | $StP{$e->byte_size}, |
1927 | $e->storage->read_at( $self->_loc_for( $idx ), $e->byte_size ), |
1928 | ); |
1929 | } |
1930 | |
1931 | sub set_entry { |
1932 | my $self = shift; |
1933 | my ($idx, $loc) = @_; |
1934 | |
1935 | my $e = $self->engine; |
1936 | |
1937 | DBM::Deep->_throw_error( "set_entry: Out of range ($idx)" ) |
1938 | if $idx < 0 || $idx >= $e->hash_chars; |
1939 | |
1940 | $self->engine->storage->print_at( |
1941 | $self->_loc_for( $idx ), |
1942 | pack( $StP{$e->byte_size}, $loc ), |
1943 | ); |
86867f3a |
1944 | } |
1945 | |
a20d9a3f |
1946 | 1; |
1947 | __END__ |