1 #TODO: Convert this to a string
2 package DBM::Deep::Engine::Sector::BucketList;
7 use warnings FATAL => 'all';
9 use DBM::Deep::Engine::Sector;
10 our @ISA = qw( DBM::Deep::Engine::Sector );
15 my $engine = $self->engine;
17 unless ( $self->offset ) {
18 my $leftover = $self->size - $self->base_size;
20 $self->{offset} = $engine->_request_blist_sector( $self->size );
21 $engine->storage->print_at( $self->offset, $engine->SIG_BLIST ); # Sector type
22 # Skip staleness counter
23 $engine->storage->print_at( $self->offset + $self->base_size,
24 chr(0) x $leftover, # Zero-fill the data
28 if ( $self->{key_md5} ) {
37 $self->engine->storage->print_at( $self->offset + $self->base_size,
38 chr(0) x ($self->size - $self->base_size), # Zero-fill the data
44 unless ( $self->{size} ) {
45 my $e = $self->engine;
46 # Base + numbuckets * bucketsize
47 $self->{size} = $self->base_size + $e->max_buckets * $self->bucket_size;
52 sub free_meth { return '_add_free_blist_sector' }
57 my $e = $self->engine;
58 foreach my $bucket ( $self->chopped_up ) {
59 my $rest = $bucket->[-1];
61 # Delete the keysector
62 my $l = unpack( $e->StP($e->byte_size), substr( $rest, $e->hash_size, $e->byte_size ) );
63 my $s = $e->_load_sector( $l ); $s->free if $s;
65 # Delete the HEAD sector
66 $l = unpack( $e->StP($e->byte_size),
68 $e->hash_size + $e->byte_size,
72 $s = $e->_load_sector( $l ); $s->free if $s;
74 foreach my $txn ( 0 .. $e->num_txns - 2 ) {
75 my $l = unpack( $e->StP($e->byte_size),
77 $e->hash_size + 2 * $e->byte_size + $txn * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE),
81 my $s = $e->_load_sector( $l ); $s->free if $s;
90 unless ( $self->{bucket_size} ) {
91 my $e = $self->engine;
92 # Key + head (location) + transactions (location + staleness-counter)
93 my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE);
94 $self->{bucket_size} = $e->hash_size + $location_size;
96 return $self->{bucket_size};
99 # XXX This is such a poor hack. I need to rethink this code.
103 my $e = $self->engine;
106 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
107 my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size;
108 my $md5 = $e->storage->read_at( $spot, $e->hash_size );
110 #XXX If we're chopping, why would we ever have the blank_md5?
111 last if $md5 eq $e->blank_md5;
113 my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size );
114 push @buckets, [ $spot, $md5 . $rest ];
120 sub write_at_next_open {
124 #XXX This is such a hack!
125 $self->{_next_open} = 0 unless exists $self->{_next_open};
127 my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size;
128 $self->engine->storage->print_at( $spot, $entry );
135 unless ( exists $self->{found} ) {
138 return $self->{found};
144 $self->{found} = undef;
148 $self->{key_md5} = shift;
151 # If we don't have an MD5, then what are we supposed to do?
152 unless ( exists $self->{key_md5} ) {
153 DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" );
156 my $e = $self->engine;
157 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
158 my $potential = $e->storage->read_at(
159 $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size,
162 if ( $potential eq $e->blank_md5 ) {
167 if ( $potential eq $self->{key_md5} ) {
181 DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key};
182 DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5};
183 DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value};
185 my $engine = $self->engine;
187 $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
189 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
190 $engine->add_entry( $args->{trans_id}, $spot );
192 unless ($self->{found}) {
193 my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({
195 data => $args->{key},
198 $engine->storage->print_at( $spot,
200 pack( $engine->StP($engine->byte_size), $key_sector->offset ),
206 + $engine->byte_size;
208 if ( $args->{trans_id} ) {
209 $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $DBM::Deep::Engine::STALE_SIZE );
211 $engine->storage->print_at( $loc,
212 pack( $engine->StP($engine->byte_size), $args->{value}->offset ),
213 pack( $engine->StP($DBM::Deep::Engine::STALE_SIZE), $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
217 $engine->storage->print_at( $loc,
218 pack( $engine->StP($engine->byte_size), $args->{value}->offset ),
228 my $engine = $self->engine;
230 $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
232 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
233 $engine->add_entry( $args->{trans_id}, $spot );
237 + $engine->byte_size;
239 if ( $args->{trans_id} ) {
240 $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $DBM::Deep::Engine::STALE_SIZE );
242 $engine->storage->print_at( $loc,
243 pack( $engine->StP($engine->byte_size), 1 ), # 1 is the marker for deleted
244 pack( $engine->StP($DBM::Deep::Engine::STALE_SIZE), $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
248 $engine->storage->print_at( $loc,
249 pack( $engine->StP($engine->byte_size), 1 ), # 1 is the marker for deleted
259 my $engine = $self->engine;
260 return undef unless $self->{found};
262 # Save the location so that we can free the data
263 my $location = $self->get_data_location_for({
266 my $key_sector = $self->get_key_for;
268 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
269 $engine->storage->print_at( $spot,
270 $engine->storage->read_at(
271 $spot + $self->bucket_size,
272 $self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ),
274 chr(0) x $self->bucket_size,
279 my $data_sector = $self->engine->_load_sector( $location );
280 my $data = $data_sector->data({ export => 1 });
286 sub get_data_location_for {
291 $args->{allow_head} = 0 unless exists $args->{allow_head};
292 $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id};
293 $args->{idx} = $self->{idx} unless exists $args->{idx};
295 my $e = $self->engine;
297 my $spot = $self->offset + $self->base_size
298 + $args->{idx} * $self->bucket_size
302 if ( $args->{trans_id} ) {
303 $spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
306 my $buffer = $e->storage->read_at(
308 $e->byte_size + $DBM::Deep::Engine::STALE_SIZE,
310 my ($loc, $staleness) = unpack( $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE), $buffer );
312 # XXX Merge the two if-clauses below
313 if ( $args->{trans_id} ) {
314 # We have found an entry that is old, so get rid of it
315 if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) {
316 $e->storage->print_at(
318 pack( $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE), (0) x 2 ),
324 # If we're in a transaction and we never wrote to this location, try the
326 if ( $args->{trans_id} && !$loc && $args->{allow_head} ) {
327 return $self->get_data_location_for({
334 return $loc <= 1 ? 0 : $loc;
342 return unless $self->{found};
343 my $location = $self->get_data_location_for({
344 allow_head => $args->{allow_head},
346 return $self->engine->_load_sector( $location );
352 $idx = $self->{idx} unless defined $idx;
354 if ( $idx >= $self->engine->max_buckets ) {
355 DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" );
358 my $location = $self->engine->storage->read_at(
359 $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size,
360 $self->engine->byte_size,
362 $location = unpack( $self->engine->StP($self->engine->byte_size), $location );
363 DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location;
365 return $self->engine->_load_sector( $location );