1 package DBM::Deep::Engine::Sector::BucketList;
6 use warnings FATAL => 'all';
8 use DBM::Deep::Engine::Sector;
9 our @ISA = qw( DBM::Deep::Engine::Sector );
14 my $engine = $self->engine;
16 unless ( $self->offset ) {
17 $self->{offset} = $engine->_request_blist_sector( $self->size );
19 $self->write( 0, $engine->SIG_BLIST );
22 if ( $self->{key_md5} ) {
33 $self->write( $self->base_size, chr(0) x ($self->size - $self->base_size) );
38 unless ( $self->{size} ) {
39 # Base + numbuckets * bucketsize
40 $self->{size} = $self->base_size + $self->engine->max_buckets * $self->bucket_size;
45 sub free_meth { return '_add_free_blist_sector' }
50 my $e = $self->engine;
51 foreach my $bucket ( $self->chopped_up ) {
52 my $rest = $bucket->[-1];
54 # Delete the keysector
55 my $l = unpack( $e->StP($e->byte_size), substr( $rest, $e->hash_size, $e->byte_size ) );
56 my $s = $e->_load_sector( $l ); $s->free if $s;
58 # Delete the HEAD sector
59 $l = unpack( $e->StP($e->byte_size),
61 $e->hash_size + $e->byte_size,
65 $s = $e->_load_sector( $l ); $s->free if $s;
67 foreach my $txn ( 0 .. $e->num_txns - 2 ) {
68 my $l = unpack( $e->StP($e->byte_size),
70 $e->hash_size + 2 * $e->byte_size + $txn * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE),
74 my $s = $e->_load_sector( $l ); $s->free if $s;
83 unless ( $self->{bucket_size} ) {
84 my $e = $self->engine;
85 # Key + head (location) + transactions (location + staleness-counter)
86 my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE);
87 $self->{bucket_size} = $e->hash_size + $location_size;
89 return $self->{bucket_size};
92 # XXX This is such a poor hack. I need to rethink this code.
96 my $e = $self->engine;
99 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
100 my $spot = $self->base_size + $idx * $self->bucket_size;
101 my $data = $self->read( $spot, $self->bucket_size );
103 # _dump_file() will run into the blank_md5. Otherwise, we should never run into it.
105 last if substr( $data, 0, $e->hash_size ) eq $e->blank_md5;
107 push @buckets, [ $spot, $data ];
113 sub write_at_next_open {
117 #XXX This is such a hack!
118 $self->{_next_open} = 0 unless exists $self->{_next_open};
120 my $spot = $self->base_size + $self->{_next_open}++ * $self->bucket_size;
121 $self->write( $spot, $entry );
128 unless ( exists $self->{found} ) {
131 return $self->{found};
137 $self->{found} = undef;
141 $self->{key_md5} = shift;
144 # If we don't have an MD5, then what are we supposed to do?
145 unless ( exists $self->{key_md5} ) {
146 DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" );
149 my $e = $self->engine;
150 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
151 my $potential = $self->read(
152 $self->base_size + $idx * $self->bucket_size, $e->hash_size,
155 if ( $potential eq $e->blank_md5 ) {
160 if ( $potential eq $self->{key_md5} ) {
174 DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key};
175 DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5};
176 DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value};
178 my $e = $self->engine;
180 $args->{trans_id} = $e->trans_id unless exists $args->{trans_id};
182 my $spot = $self->base_size + $self->{idx} * $self->bucket_size;
183 $e->add_entry( $args->{trans_id}, $self->offset + $spot );
185 unless ($self->{found}) {
186 my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({
188 data => $args->{key},
191 $self->write( $spot, $args->{key_md5} . pack( $e->StP($e->byte_size), $key_sector->offset ) );
194 my $loc = $spot + $e->hash_size + $e->byte_size;
196 if ( $args->{trans_id} ) {
197 $loc += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
200 pack( $e->StP($e->byte_size), $args->{value}->offset )
201 . pack( $e->StP($DBM::Deep::Engine::STALE_SIZE), $e->get_txn_staleness_counter( $args->{trans_id} ) ),
205 $self->write( $loc, pack( $e->StP($e->byte_size), $args->{value}->offset ) );
214 my $e = $self->engine;
216 $args->{trans_id} = $e->trans_id unless exists $args->{trans_id};
218 my $spot = $self->base_size + $self->{idx} * $self->bucket_size;
219 $e->add_entry( $args->{trans_id}, $self->offset + $spot );
225 if ( $args->{trans_id} ) {
226 $loc += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
229 pack( $e->StP($e->byte_size), 1 ) # 1 is the marker for deleted
230 . pack( $e->StP($DBM::Deep::Engine::STALE_SIZE), $e->get_txn_staleness_counter( $args->{trans_id} ) ),
234 # 1 is the marker for deleted
235 $self->write( $loc, pack( $e->StP($e->byte_size), 1 ) );
243 my $engine = $self->engine;
244 return undef unless $self->{found};
246 # Save the location so that we can free the data
247 my $location = $self->get_data_location_for({
250 my $key_sector = $self->get_key_for;
252 my $spot = $self->base_size + $self->{idx} * $self->bucket_size;
254 # Shuffle everything down to cover the deleted bucket's spot.
257 $spot + $self->bucket_size,
258 $self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ),
260 . chr(0) x $self->bucket_size,
265 my $data_sector = $self->engine->_load_sector( $location );
266 my $data = $data_sector->data({ export => 1 });
272 sub get_data_location_for {
277 $args->{allow_head} = 0 unless exists $args->{allow_head};
278 $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id};
279 $args->{idx} = $self->{idx} unless exists $args->{idx};
281 my $e = $self->engine;
283 my $spot = $self->base_size
284 + $args->{idx} * $self->bucket_size
288 if ( $args->{trans_id} ) {
289 $spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
292 my $buffer = $self->read( $spot, $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
293 my ($loc, $staleness) = unpack(
294 $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE),
298 # XXX Merge the two if-clauses below
299 if ( $args->{trans_id} ) {
300 # We have found an entry that is old, so get rid of it
301 if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) {
302 $e->storage->print_at(
304 pack( $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE), (0) x 2 ),
310 # If we're in a transaction and we never wrote to this location, try the
312 if ( $args->{trans_id} && !$loc && $args->{allow_head} ) {
313 return $self->get_data_location_for({
320 return $loc <= 1 ? 0 : $loc;
328 return unless $self->{found};
329 my $location = $self->get_data_location_for({
330 allow_head => $args->{allow_head},
332 return $self->engine->_load_sector( $location );
338 $idx = $self->{idx} unless defined $idx;
340 if ( $idx >= $self->engine->max_buckets ) {
341 DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" );
344 my $location = $self->read(
345 $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size,
346 $self->engine->byte_size,
348 $location = unpack( $self->engine->StP($self->engine->byte_size), $location );
349 DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location;
351 return $self->engine->_load_sector( $location );