Commit | Line | Data |
f0276afb |
1 | package DBM::Deep::Engine::Sector::BucketList; |
2 | |
3 | use 5.006_000; |
4 | |
5 | use strict; |
6 | use warnings FATAL => 'all'; |
7 | |
8 | use base qw( DBM::Deep::Engine::Sector ); |
9 | |
10 | sub _init { |
11 | my $self = shift; |
12 | |
13 | my $engine = $self->engine; |
14 | |
15 | unless ( $self->offset ) { |
16 | my $leftover = $self->size - $self->base_size; |
17 | |
18 | $self->{offset} = $engine->_request_blist_sector( $self->size ); |
19 | $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type |
20 | # Skip staleness counter |
21 | $engine->storage->print_at( $self->offset + $self->base_size, |
22 | chr(0) x $leftover, # Zero-fill the data |
23 | ); |
24 | } |
25 | |
26 | if ( $self->{key_md5} ) { |
27 | $self->find_md5; |
28 | } |
29 | |
30 | return $self; |
31 | } |
32 | |
33 | sub clear { |
34 | my $self = shift; |
35 | $self->engine->storage->print_at( $self->offset + $self->base_size, |
36 | chr(0) x ($self->size - $self->base_size), # Zero-fill the data |
37 | ); |
38 | } |
39 | |
40 | sub size { |
41 | my $self = shift; |
42 | unless ( $self->{size} ) { |
43 | my $e = $self->engine; |
44 | # Base + numbuckets * bucketsize |
45 | $self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size; |
46 | } |
47 | return $self->{size}; |
48 | } |
49 | |
50 | sub free_meth { return '_add_free_blist_sector' } |
51 | |
52 | sub free { |
53 | my $self = shift; |
54 | |
55 | my $e = $self->engine; |
56 | foreach my $bucket ( $self->chopped_up ) { |
57 | my $rest = $bucket->[-1]; |
58 | |
59 | # Delete the keysector |
60 | my $l = unpack( $StP{$e->byte_size}, substr( $rest, $e->hash_size, $e->byte_size ) ); |
61 | my $s = $e->_load_sector( $l ); $s->free if $s; |
62 | |
63 | # Delete the HEAD sector |
64 | $l = unpack( $StP{$e->byte_size}, |
65 | substr( $rest, |
66 | $e->hash_size + $e->byte_size, |
67 | $e->byte_size, |
68 | ), |
69 | ); |
70 | $s = $e->_load_sector( $l ); $s->free if $s; |
71 | |
72 | foreach my $txn ( 0 .. $e->num_txns - 2 ) { |
73 | my $l = unpack( $StP{$e->byte_size}, |
74 | substr( $rest, |
75 | $e->hash_size + 2 * $e->byte_size + $txn * ($e->byte_size + $STALE_SIZE), |
76 | $e->byte_size, |
77 | ), |
78 | ); |
79 | my $s = $e->_load_sector( $l ); $s->free if $s; |
80 | } |
81 | } |
82 | |
83 | $self->SUPER::free(); |
84 | } |
85 | |
86 | sub bucket_size { |
87 | my $self = shift; |
88 | unless ( $self->{bucket_size} ) { |
89 | my $e = $self->engine; |
90 | # Key + head (location) + transactions (location + staleness-counter) |
91 | my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $STALE_SIZE); |
92 | $self->{bucket_size} = $e->hash_size + $location_size; |
93 | } |
94 | return $self->{bucket_size}; |
95 | } |
96 | |
97 | # XXX This is such a poor hack. I need to rethink this code. |
98 | sub chopped_up { |
99 | my $self = shift; |
100 | |
101 | my $e = $self->engine; |
102 | |
103 | my @buckets; |
104 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
105 | my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size; |
106 | my $md5 = $e->storage->read_at( $spot, $e->hash_size ); |
107 | |
108 | #XXX If we're chopping, why would we ever have the blank_md5? |
109 | last if $md5 eq $e->blank_md5; |
110 | |
111 | my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size ); |
112 | push @buckets, [ $spot, $md5 . $rest ]; |
113 | } |
114 | |
115 | return @buckets; |
116 | } |
117 | |
118 | sub write_at_next_open { |
119 | my $self = shift; |
120 | my ($entry) = @_; |
121 | |
122 | #XXX This is such a hack! |
123 | $self->{_next_open} = 0 unless exists $self->{_next_open}; |
124 | |
125 | my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size; |
126 | $self->engine->storage->print_at( $spot, $entry ); |
127 | |
128 | return $spot; |
129 | } |
130 | |
131 | sub has_md5 { |
132 | my $self = shift; |
133 | unless ( exists $self->{found} ) { |
134 | $self->find_md5; |
135 | } |
136 | return $self->{found}; |
137 | } |
138 | |
139 | sub find_md5 { |
140 | my $self = shift; |
141 | |
142 | $self->{found} = undef; |
143 | $self->{idx} = -1; |
144 | |
145 | if ( @_ ) { |
146 | $self->{key_md5} = shift; |
147 | } |
148 | |
149 | # If we don't have an MD5, then what are we supposed to do? |
150 | unless ( exists $self->{key_md5} ) { |
151 | DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" ); |
152 | } |
153 | |
154 | my $e = $self->engine; |
155 | foreach my $idx ( 0 .. $e->max_buckets - 1 ) { |
156 | my $potential = $e->storage->read_at( |
157 | $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size, |
158 | ); |
159 | |
160 | if ( $potential eq $e->blank_md5 ) { |
161 | $self->{idx} = $idx; |
162 | return; |
163 | } |
164 | |
165 | if ( $potential eq $self->{key_md5} ) { |
166 | $self->{found} = 1; |
167 | $self->{idx} = $idx; |
168 | return; |
169 | } |
170 | } |
171 | |
172 | return; |
173 | } |
174 | |
175 | sub write_md5 { |
176 | my $self = shift; |
177 | my ($args) = @_; |
178 | |
179 | DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key}; |
180 | DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5}; |
181 | DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value}; |
182 | |
183 | my $engine = $self->engine; |
184 | |
185 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
186 | |
187 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
188 | $engine->add_entry( $args->{trans_id}, $spot ); |
189 | |
190 | unless ($self->{found}) { |
191 | my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({ |
192 | engine => $engine, |
193 | data => $args->{key}, |
194 | }); |
195 | |
196 | $engine->storage->print_at( $spot, |
197 | $args->{key_md5}, |
198 | pack( $StP{$engine->byte_size}, $key_sector->offset ), |
199 | ); |
200 | } |
201 | |
202 | my $loc = $spot |
203 | + $engine->hash_size |
204 | + $engine->byte_size; |
205 | |
206 | if ( $args->{trans_id} ) { |
207 | $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE ); |
208 | |
209 | $engine->storage->print_at( $loc, |
210 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
211 | pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
212 | ); |
213 | } |
214 | else { |
215 | $engine->storage->print_at( $loc, |
216 | pack( $StP{$engine->byte_size}, $args->{value}->offset ), |
217 | ); |
218 | } |
219 | } |
220 | |
221 | sub mark_deleted { |
222 | my $self = shift; |
223 | my ($args) = @_; |
224 | $args ||= {}; |
225 | |
226 | my $engine = $self->engine; |
227 | |
228 | $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id}; |
229 | |
230 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
231 | $engine->add_entry( $args->{trans_id}, $spot ); |
232 | |
233 | my $loc = $spot |
234 | + $engine->hash_size |
235 | + $engine->byte_size; |
236 | |
237 | if ( $args->{trans_id} ) { |
238 | $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $STALE_SIZE ); |
239 | |
240 | $engine->storage->print_at( $loc, |
241 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
242 | pack( $StP{$STALE_SIZE}, $engine->get_txn_staleness_counter( $args->{trans_id} ) ), |
243 | ); |
244 | } |
245 | else { |
246 | $engine->storage->print_at( $loc, |
247 | pack( $StP{$engine->byte_size}, 1 ), # 1 is the marker for deleted |
248 | ); |
249 | } |
250 | } |
251 | |
252 | sub delete_md5 { |
253 | my $self = shift; |
254 | my ($args) = @_; |
255 | |
256 | my $engine = $self->engine; |
257 | return undef unless $self->{found}; |
258 | |
259 | # Save the location so that we can free the data |
260 | my $location = $self->get_data_location_for({ |
261 | allow_head => 0, |
262 | }); |
263 | my $key_sector = $self->get_key_for; |
264 | |
265 | my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size; |
266 | $engine->storage->print_at( $spot, |
267 | $engine->storage->read_at( |
268 | $spot + $self->bucket_size, |
269 | $self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ), |
270 | ), |
271 | chr(0) x $self->bucket_size, |
272 | ); |
273 | |
274 | $key_sector->free; |
275 | |
276 | my $data_sector = $self->engine->_load_sector( $location ); |
277 | my $data = $data_sector->data({ export => 1 }); |
278 | $data_sector->free; |
279 | |
280 | return $data; |
281 | } |
282 | |
283 | sub get_data_location_for { |
284 | my $self = shift; |
285 | my ($args) = @_; |
286 | $args ||= {}; |
287 | |
288 | $args->{allow_head} = 0 unless exists $args->{allow_head}; |
289 | $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id}; |
290 | $args->{idx} = $self->{idx} unless exists $args->{idx}; |
291 | |
292 | my $e = $self->engine; |
293 | |
294 | my $spot = $self->offset + $self->base_size |
295 | + $args->{idx} * $self->bucket_size |
296 | + $e->hash_size |
297 | + $e->byte_size; |
298 | |
299 | if ( $args->{trans_id} ) { |
300 | $spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $STALE_SIZE ); |
301 | } |
302 | |
303 | my $buffer = $e->storage->read_at( |
304 | $spot, |
305 | $e->byte_size + $STALE_SIZE, |
306 | ); |
307 | my ($loc, $staleness) = unpack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, $buffer ); |
308 | |
309 | # XXX Merge the two if-clauses below |
310 | if ( $args->{trans_id} ) { |
311 | # We have found an entry that is old, so get rid of it |
312 | if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) { |
313 | $e->storage->print_at( |
314 | $spot, |
315 | pack( $StP{$e->byte_size} . ' ' . $StP{$STALE_SIZE}, (0) x 2 ), |
316 | ); |
317 | $loc = 0; |
318 | } |
319 | } |
320 | |
321 | # If we're in a transaction and we never wrote to this location, try the |
322 | # HEAD instead. |
323 | if ( $args->{trans_id} && !$loc && $args->{allow_head} ) { |
324 | return $self->get_data_location_for({ |
325 | trans_id => 0, |
326 | allow_head => 1, |
327 | idx => $args->{idx}, |
328 | }); |
329 | } |
330 | |
331 | return $loc <= 1 ? 0 : $loc; |
332 | } |
333 | |
334 | sub get_data_for { |
335 | my $self = shift; |
336 | my ($args) = @_; |
337 | $args ||= {}; |
338 | |
339 | return unless $self->{found}; |
340 | my $location = $self->get_data_location_for({ |
341 | allow_head => $args->{allow_head}, |
342 | }); |
343 | return $self->engine->_load_sector( $location ); |
344 | } |
345 | |
346 | sub get_key_for { |
347 | my $self = shift; |
348 | my ($idx) = @_; |
349 | $idx = $self->{idx} unless defined $idx; |
350 | |
351 | if ( $idx >= $self->engine->max_buckets ) { |
352 | DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" ); |
353 | } |
354 | |
355 | my $location = $self->engine->storage->read_at( |
356 | $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size, |
357 | $self->engine->byte_size, |
358 | ); |
359 | $location = unpack( $StP{$self->engine->byte_size}, $location ); |
360 | DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location; |
361 | |
362 | return $self->engine->_load_sector( $location ); |
363 | } |
364 | |
365 | 1; |
366 | __END__ |