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 $self->{offset} = $engine->_request_blist_sector( $self->size );
20 my $string = chr(0) x $self->size;
21 substr( $string, 0, 1, $engine->SIG_BLIST );
22 $engine->storage->print_at( $self->offset, $string );
25 if ( $self->{key_md5} ) {
34 $self->engine->storage->print_at( $self->offset + $self->base_size,
35 chr(0) x ($self->size - $self->base_size), # Zero-fill the data
41 unless ( $self->{size} ) {
42 # Base + numbuckets * bucketsize
43 $self->{size} = $self->base_size + $self->engine->max_buckets * $self->bucket_size;
48 sub free_meth { return '_add_free_blist_sector' }
53 my $e = $self->engine;
54 foreach my $bucket ( $self->chopped_up ) {
55 my $rest = $bucket->[-1];
57 # Delete the keysector
58 my $l = unpack( $e->StP($e->byte_size), substr( $rest, $e->hash_size, $e->byte_size ) );
59 my $s = $e->_load_sector( $l ); $s->free if $s;
61 # Delete the HEAD sector
62 $l = unpack( $e->StP($e->byte_size),
64 $e->hash_size + $e->byte_size,
68 $s = $e->_load_sector( $l ); $s->free if $s;
70 foreach my $txn ( 0 .. $e->num_txns - 2 ) {
71 my $l = unpack( $e->StP($e->byte_size),
73 $e->hash_size + 2 * $e->byte_size + $txn * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE),
77 my $s = $e->_load_sector( $l ); $s->free if $s;
86 unless ( $self->{bucket_size} ) {
87 my $e = $self->engine;
88 # Key + head (location) + transactions (location + staleness-counter)
89 my $location_size = $e->byte_size + $e->byte_size + ($e->num_txns - 1) * ($e->byte_size + $DBM::Deep::Engine::STALE_SIZE);
90 $self->{bucket_size} = $e->hash_size + $location_size;
92 return $self->{bucket_size};
95 # XXX This is such a poor hack. I need to rethink this code.
99 my $e = $self->engine;
102 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
103 my $spot = $self->offset + $self->base_size + $idx * $self->bucket_size;
104 my $md5 = $e->storage->read_at( $spot, $e->hash_size );
106 #XXX If we're chopping, why would we ever have the blank_md5?
107 last if $md5 eq $e->blank_md5;
109 my $rest = $e->storage->read_at( undef, $self->bucket_size - $e->hash_size );
110 push @buckets, [ $spot, $md5 . $rest ];
116 sub write_at_next_open {
120 #XXX This is such a hack!
121 $self->{_next_open} = 0 unless exists $self->{_next_open};
123 my $spot = $self->offset + $self->base_size + $self->{_next_open}++ * $self->bucket_size;
124 $self->engine->storage->print_at( $spot, $entry );
131 unless ( exists $self->{found} ) {
134 return $self->{found};
140 $self->{found} = undef;
144 $self->{key_md5} = shift;
147 # If we don't have an MD5, then what are we supposed to do?
148 unless ( exists $self->{key_md5} ) {
149 DBM::Deep->_throw_error( "Cannot find_md5 without a key_md5 set" );
152 my $e = $self->engine;
153 foreach my $idx ( 0 .. $e->max_buckets - 1 ) {
154 my $potential = $e->storage->read_at(
155 $self->offset + $self->base_size + $idx * $self->bucket_size, $e->hash_size,
158 if ( $potential eq $e->blank_md5 ) {
163 if ( $potential eq $self->{key_md5} ) {
177 DBM::Deep->_throw_error( "write_md5: no key" ) unless exists $args->{key};
178 DBM::Deep->_throw_error( "write_md5: no key_md5" ) unless exists $args->{key_md5};
179 DBM::Deep->_throw_error( "write_md5: no value" ) unless exists $args->{value};
181 my $engine = $self->engine;
183 $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
185 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
186 $engine->add_entry( $args->{trans_id}, $spot );
188 unless ($self->{found}) {
189 my $key_sector = DBM::Deep::Engine::Sector::Scalar->new({
191 data => $args->{key},
194 $engine->storage->print_at( $spot,
196 pack( $engine->StP($engine->byte_size), $key_sector->offset ),
202 + $engine->byte_size;
204 if ( $args->{trans_id} ) {
205 $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $DBM::Deep::Engine::STALE_SIZE );
207 $engine->storage->print_at( $loc,
208 pack( $engine->StP($engine->byte_size), $args->{value}->offset ),
209 pack( $engine->StP($DBM::Deep::Engine::STALE_SIZE), $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
213 $engine->storage->print_at( $loc,
214 pack( $engine->StP($engine->byte_size), $args->{value}->offset ),
224 my $engine = $self->engine;
226 $args->{trans_id} = $engine->trans_id unless exists $args->{trans_id};
228 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
229 $engine->add_entry( $args->{trans_id}, $spot );
233 + $engine->byte_size;
235 if ( $args->{trans_id} ) {
236 $loc += $engine->byte_size + ($args->{trans_id} - 1) * ( $engine->byte_size + $DBM::Deep::Engine::STALE_SIZE );
238 $engine->storage->print_at( $loc,
239 pack( $engine->StP($engine->byte_size), 1 ), # 1 is the marker for deleted
240 pack( $engine->StP($DBM::Deep::Engine::STALE_SIZE), $engine->get_txn_staleness_counter( $args->{trans_id} ) ),
244 $engine->storage->print_at( $loc,
245 pack( $engine->StP($engine->byte_size), 1 ), # 1 is the marker for deleted
255 my $engine = $self->engine;
256 return undef unless $self->{found};
258 # Save the location so that we can free the data
259 my $location = $self->get_data_location_for({
262 my $key_sector = $self->get_key_for;
264 my $spot = $self->offset + $self->base_size + $self->{idx} * $self->bucket_size;
265 $engine->storage->print_at( $spot,
266 $engine->storage->read_at(
267 $spot + $self->bucket_size,
268 $self->bucket_size * ( $engine->max_buckets - $self->{idx} - 1 ),
270 chr(0) x $self->bucket_size,
275 my $data_sector = $self->engine->_load_sector( $location );
276 my $data = $data_sector->data({ export => 1 });
282 sub get_data_location_for {
287 $args->{allow_head} = 0 unless exists $args->{allow_head};
288 $args->{trans_id} = $self->engine->trans_id unless exists $args->{trans_id};
289 $args->{idx} = $self->{idx} unless exists $args->{idx};
291 my $e = $self->engine;
293 my $spot = $self->offset + $self->base_size
294 + $args->{idx} * $self->bucket_size
298 if ( $args->{trans_id} ) {
299 $spot += $e->byte_size + ($args->{trans_id} - 1) * ( $e->byte_size + $DBM::Deep::Engine::STALE_SIZE );
302 my $buffer = $e->storage->read_at(
304 $e->byte_size + $DBM::Deep::Engine::STALE_SIZE,
306 my ($loc, $staleness) = unpack( $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE), $buffer );
308 # XXX Merge the two if-clauses below
309 if ( $args->{trans_id} ) {
310 # We have found an entry that is old, so get rid of it
311 if ( $staleness != (my $s = $e->get_txn_staleness_counter( $args->{trans_id} ) ) ) {
312 $e->storage->print_at(
314 pack( $e->StP($e->byte_size) . ' ' . $e->StP($DBM::Deep::Engine::STALE_SIZE), (0) x 2 ),
320 # If we're in a transaction and we never wrote to this location, try the
322 if ( $args->{trans_id} && !$loc && $args->{allow_head} ) {
323 return $self->get_data_location_for({
330 return $loc <= 1 ? 0 : $loc;
338 return unless $self->{found};
339 my $location = $self->get_data_location_for({
340 allow_head => $args->{allow_head},
342 return $self->engine->_load_sector( $location );
348 $idx = $self->{idx} unless defined $idx;
350 if ( $idx >= $self->engine->max_buckets ) {
351 DBM::Deep->_throw_error( "get_key_for(): Attempting to retrieve $idx" );
354 my $location = $self->engine->storage->read_at(
355 $self->offset + $self->base_size + $idx * $self->bucket_size + $self->engine->hash_size,
356 $self->engine->byte_size,
358 $location = unpack( $self->engine->StP($self->engine->byte_size), $location );
359 DBM::Deep->_throw_error( "get_key_for: No location?" ) unless $location;
361 return $self->engine->_load_sector( $location );