1 package DBM::Deep::Engine;
3 use Sub::Caller qw( load_tag );
9 our $VERSION = q(0.99_03);
11 use Fcntl qw( :DEFAULT :flock );
15 # * To add to bucket_size, make sure you modify the following:
18 # - add_bucket() - where the buckets are printed
20 # * Every method in here assumes that the _storage has been appropriately
21 # safeguarded. This can be anything from flock() to some sort of manual
22 # mutex. But, it's the caller's responsability to make sure that this has
26 # Setup file and tag signatures. These should never change.
28 sub SIG_FILE () { 'DPDB' }
29 sub SIG_HEADER () { 'h' }
30 sub SIG_INTERNAL () { 'i' }
31 sub SIG_HASH () { 'H' }
32 sub SIG_ARRAY () { 'A' }
33 sub SIG_NULL () { 'N' }
34 sub SIG_DATA () { 'D' }
35 sub SIG_INDEX () { 'I' }
36 sub SIG_BLIST () { 'B' }
37 sub SIG_FREE () { 'F' }
38 sub SIG_KEYS () { 'K' }
41 # This is the transaction ID for the HEAD
44 ################################################################################
46 # This is new code. It is a complete rewrite of the engine based on a new API
48 ################################################################################
52 my ($trans_id, $offset, $key, $orig_key) = @_;
54 my $dig_key = $self->_apply_digest( $key );
55 my $tag = $self->find_blist( $offset, $dig_key ) or return;
56 return $self->get_bucket_value( $tag, $dig_key, $orig_key );
61 my ($trans_id, $offset, $key) = @_;
63 my $dig_key = $self->_apply_digest( $key );
64 # exists() returns the empty string, not undef
65 my $tag = $self->find_blist( $offset, $dig_key ) or return '';
66 return $self->bucket_exists( $tag, $dig_key, $key );
71 my ($trans_id, $offset) = @_;
73 # If the previous key was not specifed, start at the top and
74 # return the first one found.
78 prev_md5 => $self->_apply_digest($_[2]),
84 prev_md5 => chr(0) x $self->{hash_size},
89 return $self->traverse_index( $temp, $offset, 0 );
94 my ($trans_id, $offset, $key, $orig_key) = @_;
96 my $dig_key = $self->_apply_digest( $key );
97 my $tag = $self->find_blist( $offset, $dig_key ) or return;
98 my $value = $self->get_bucket_value( $tag, $dig_key, $orig_key );
99 $self->delete_bucket( $tag, $dig_key, $orig_key );
105 my ($trans_id, $offset, $key, $value, $orig_key) = @_;
107 my $dig_key = $self->_apply_digest( $key );
108 my $tag = $self->find_blist( $offset, $dig_key, { create => 1 } );
109 return $self->add_bucket( $tag, $dig_key, $key, $value, undef, $orig_key );
112 ################################################################################
114 # Below here is the old code. It will be folded into the code above as it can.
116 ################################################################################
128 digest => \&Digest::MD5::md5,
129 hash_size => 16, # In bytes
132 # Number of buckets per blist before another level of indexing is
133 # done. Increase this value for slightly greater speed, but larger database
134 # files. DO NOT decrease this value below 16, due to risk of recursive
143 if ( defined $args->{pack_size} ) {
144 if ( lc $args->{pack_size} eq 'small' ) {
145 $args->{long_size} = 2;
146 $args->{long_pack} = 'n';
148 elsif ( lc $args->{pack_size} eq 'medium' ) {
149 $args->{long_size} = 4;
150 $args->{long_pack} = 'N';
152 elsif ( lc $args->{pack_size} eq 'large' ) {
153 $args->{long_size} = 8;
154 $args->{long_pack} = 'Q';
157 die "Unknown pack_size value: '$args->{pack_size}'\n";
161 # Grab the parameters we want to use
162 foreach my $param ( keys %$self ) {
163 next unless exists $args->{$param};
164 $self->{$param} = $args->{$param};
166 Scalar::Util::weaken( $self->{obj} ) if $self->{obj};
168 if ( $self->{max_buckets} < 16 ) {
169 warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n";
170 $self->{max_buckets} = 16;
176 sub _storage { return $_[0]{storage} }
180 return $self->{digest}->(@_);
183 sub calculate_sizes {
186 # The 2**8 here indicates the number of different characters in the
187 # current hashing algorithm
188 #XXX Does this need to be updated with different hashing algorithms?
189 $self->{hash_chars_used} = (2**8);
190 $self->{index_size} = $self->{hash_chars_used} * $self->{long_size};
192 $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2;
193 $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
195 $self->{key_size} = $self->{long_size} * 2;
196 $self->{keyloc_size} = $self->{max_buckets} * $self->{key_size};
201 sub write_file_header {
204 my $loc = $self->_storage->request_space( length( SIG_FILE ) + 33 );
206 $self->_storage->print_at( $loc,
209 pack('N', 1), # header version
210 pack('N', 24), # header size
211 pack('N4', 0, 0, 0, 0), # currently running transaction IDs
212 pack('n', $self->{long_size}),
213 pack('A', $self->{long_pack}),
214 pack('n', $self->{data_size}),
215 pack('A', $self->{data_pack}),
216 pack('n', $self->{max_buckets}),
219 $self->_storage->set_transaction_offset( 13 );
224 sub read_file_header {
227 my $buffer = $self->_storage->read_at( 0, length(SIG_FILE) + 9 );
228 return unless length($buffer);
230 my ($file_signature, $sig_header, $header_version, $size) = unpack(
234 unless ( $file_signature eq SIG_FILE ) {
235 $self->_storage->close;
236 $self->_throw_error( "Signature not found -- file is not a Deep DB" );
239 unless ( $sig_header eq SIG_HEADER ) {
240 $self->_storage->close;
241 $self->_throw_error( "Old file version found." );
244 my $buffer2 = $self->_storage->read_at( undef, $size );
245 my ($a1, $a2, $a3, $a4, @values) = unpack( 'N4 n A n A n', $buffer2 );
247 $self->_storage->set_transaction_offset( 13 );
249 if ( @values < 5 || grep { !defined } @values ) {
250 $self->_storage->close;
251 $self->_throw_error("Corrupted file - bad header");
254 #XXX Add warnings if values weren't set right
255 @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values;
257 return length($buffer) + length($buffer2);
264 # Need to remove use of $fh here
265 my $fh = $self->_storage->{fh};
268 #XXX The duplication of calculate_sizes needs to go away
269 unless ( $obj->{base_offset} ) {
270 my $bytes_read = $self->read_file_header;
272 $self->calculate_sizes;
275 # File is empty -- write header and master index
278 $self->_storage->audit( "# Database created on" );
280 $self->write_file_header;
282 $obj->{base_offset} = $self->_storage->request_space(
283 $self->tag_size( $self->{index_size} ),
287 $obj->_base_offset, $obj->_type,
288 chr(0)x$self->{index_size},
291 # Flush the filehandle
292 my $old_fh = select $fh;
293 my $old_af = $|; $| = 1; $| = $old_af;
297 $obj->{base_offset} = $bytes_read;
300 # Get our type from master index header
302 my $tag = $self->load_tag($obj->_base_offset);
305 $self->_throw_error("Corrupted file, no master index record");
308 unless ($obj->_type eq $tag->{signature}) {
310 $self->_throw_error("File type mismatch");
315 $self->calculate_sizes;
318 #XXX We have to make sure we don't mess up when autoflush isn't turned on
319 $self->_storage->set_inode;
329 return SIG_SIZE + $self->{data_size} + $size;
334 # Given offset, signature and content, create tag and write to disk
337 my ($offset, $sig, $content) = @_;
338 my $size = length( $content );
340 $self->_storage->print_at(
342 $sig, pack($self->{data_pack}, $size), $content,
345 return unless defined $offset;
349 #XXX Is this even used?
352 offset => $offset + SIG_SIZE + $self->{data_size},
360 # Given offset, load single tag and return signature, size and data
364 print join(":",caller) . " - load_tag($offset)\n" if $::DEBUG;
366 my $storage = $self->_storage;
368 my ($sig, $size) = unpack(
369 "A $self->{data_pack}",
370 $storage->read_at( $offset, SIG_SIZE + $self->{data_size} ),
375 size => $size, #XXX Is this even used?
377 offset => $offset + SIG_SIZE + $self->{data_size},
378 content => $storage->read_at( undef, $size ),
384 my ($tag, $transaction_id) = @_;
385 $transaction_id = $self->_storage->transaction_id
386 unless defined $transaction_id;
388 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
389 my ($loc, $trans_id, $is_deleted) = unpack(
390 "$self->{long_pack} C C",
391 substr( $tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
394 next if $loc != HEAD && $transaction_id != $trans_id;
395 return( $loc, $is_deleted, $i * $self->{key_size} );
403 # Adds one key/value pair to bucket list, given offset, MD5 digest of key,
404 # plain (undigested) key and value.
407 my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_;
409 # This verifies that only supported values will be stored.
411 my $r = Scalar::Util::reftype( $value );
414 last if $r eq 'HASH';
415 last if $r eq 'ARRAY';
418 "Storage of references of type '$r' is not supported."
422 my $storage = $self->_storage;
424 #ACID - This is a mutation. Must only find the exact transaction
425 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5, 1 );
428 if ( $storage->transaction_id == 0 ) {
429 @transactions = $storage->current_transactions;
432 # $self->_release_space( $size, $subloc );
433 #XXX This needs updating to use _release_space
436 my $size = $self->_length_needed( $value, $plain_key );
438 # Updating a known md5
440 my $keytag = $self->load_tag( $keyloc );
441 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
443 if ( $subloc && !$is_deleted && @transactions ) {
444 my $old_value = $self->read_from_loc( $subloc, $orig_key );
445 my $old_size = $self->_length_needed( $old_value, $plain_key );
447 for my $trans_id ( @transactions ) {
448 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
450 my $location2 = $storage->request_space( $old_size );
451 $storage->print_at( $keytag->{offset} + $offset2,
452 pack($self->{long_pack}, $location2 ),
453 pack( 'C C', $trans_id, 0 ),
455 $self->_write_value( $location2, $plain_key, $old_value, $orig_key );
460 $location = $self->_storage->request_space( $size );
461 #XXX This needs to be transactionally-aware in terms of which keytag->{offset} to use
462 $storage->print_at( $keytag->{offset} + $offset,
463 pack($self->{long_pack}, $location ),
464 pack( 'C C', $storage->transaction_id, 0 ),
469 my $keyloc = $storage->request_space( $self->tag_size( $self->{keyloc_size} ) );
471 # The bucket fit into list
472 if ( defined $offset ) {
473 $storage->print_at( $tag->{offset} + $offset,
474 $md5, pack( $self->{long_pack}, $keyloc ),
477 # If bucket didn't fit into list, split into a new index level
479 $self->split_index( $tag, $md5, $keyloc );
482 my $keytag = $self->write_tag(
483 $keyloc, SIG_KEYS, chr(0)x$self->{keyloc_size},
486 $location = $self->_storage->request_space( $size );
487 $storage->print_at( $keytag->{offset},
488 pack( $self->{long_pack}, $location ),
489 pack( 'C C', $storage->transaction_id, 0 ),
493 for my $trans_id ( @transactions ) {
494 $storage->print_at( $keytag->{offset} + $self->{key_size} * $offset++,
495 pack( $self->{long_pack}, 0 ),
496 pack( 'C C', $trans_id, 1 ),
501 $self->_write_value( $location, $plain_key, $value, $orig_key );
508 my ($key_loc, $location, $key, $value, $orig_key) = @_;
510 my $storage = $self->_storage;
512 my $dbm_deep_obj = _get_dbm_object( $value );
513 if ( $dbm_deep_obj && $dbm_deep_obj->_storage ne $storage ) {
514 $self->_throw_error( "Cannot cross-reference. Use export() instead" );
518 # Write signature based on content type, set content length and write
521 my $r = Scalar::Util::reftype( $value ) || '';
522 if ( $dbm_deep_obj ) {
523 $self->write_tag( $location, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) );
525 elsif ($r eq 'HASH') {
526 if ( !$dbm_deep_obj && tied %{$value} ) {
527 $self->_throw_error( "Cannot store something that is tied" );
529 $self->write_tag( $location, SIG_HASH, chr(0)x$self->{index_size} );
531 elsif ($r eq 'ARRAY') {
532 if ( !$dbm_deep_obj && tied @{$value} ) {
533 $self->_throw_error( "Cannot store something that is tied" );
535 $self->write_tag( $location, SIG_ARRAY, chr(0)x$self->{index_size} );
537 elsif (!defined($value)) {
538 $self->write_tag( $location, SIG_NULL, '' );
541 $self->write_tag( $location, SIG_DATA, $value );
545 # Plain key is stored AFTER value, as keys are typically fetched less often.
547 $storage->print_at( undef, pack($self->{data_pack}, length($key)) . $key );
549 # Internal references don't care about autobless
550 return 1 if $dbm_deep_obj;
553 # If value is blessed, preserve class name
555 if ( $storage->{autobless} ) {
556 if ( defined( my $c = Scalar::Util::blessed($value) ) ) {
557 $storage->print_at( undef, chr(1), pack($self->{data_pack}, length($c)) . $c );
560 $storage->print_at( undef, chr(0) );
565 # Tie the passed in reference so that changes to it are reflected in the
566 # datafile. The use of $location as the base_offset will act as the
567 # the linkage between parent and child.
569 # The overall assignment is a hack around the fact that just tying doesn't
570 # store the values. This may not be the wrong thing to do.
574 tie %$value, 'DBM::Deep', {
575 base_offset => $key_loc,
577 parent => $self->{obj},
578 parent_key => $orig_key,
581 bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value );
583 elsif ($r eq 'ARRAY') {
585 tie @$value, 'DBM::Deep', {
586 base_offset => $key_loc,
588 parent => $self->{obj},
589 parent_key => $orig_key,
592 bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value );
600 my ($tag, $md5, $keyloc) = @_;
602 my $storage = $self->_storage;
604 my $loc = $storage->request_space(
605 $self->tag_size( $self->{index_size} ),
608 $storage->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) );
610 my $index_tag = $self->write_tag(
612 chr(0)x$self->{index_size},
615 my $keys = $tag->{content}
616 . $md5 . pack($self->{long_pack}, $keyloc);
620 # The <= here is deliberate - we have max_buckets+1 keys to iterate
621 # through, unlike every other loop that uses max_buckets as a stop.
622 for (my $i = 0; $i <= $self->{max_buckets}; $i++) {
623 my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i );
625 die "[INTERNAL ERROR]: No key in split_index()\n" unless $key;
626 die "[INTERNAL ERROR]: No subloc in split_index()\n" unless $old_subloc;
628 my $num = ord(substr($key, $tag->{ch} + 1, 1));
631 my $subkeys = $storage->read_at( $newloc[$num], $self->{bucket_list_size} );
633 # This is looking for the first empty spot
634 my ($subloc, $offset) = $self->_find_in_buckets(
635 { content => $subkeys }, '',
639 $newloc[$num] + $offset,
640 $key, pack($self->{long_pack}, $old_subloc),
646 my $loc = $storage->request_space(
647 $self->tag_size( $self->{bucket_list_size} ),
651 $index_tag->{offset} + ($num * $self->{long_size}),
652 pack($self->{long_pack}, $loc),
655 my $blist_tag = $self->write_tag(
657 chr(0)x$self->{bucket_list_size},
660 $storage->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) );
662 $newloc[$num] = $blist_tag->{offset};
665 $self->_release_space(
666 $self->tag_size( $self->{bucket_list_size} ),
675 my ($key_loc, $subloc, $orig_key) = @_;
677 my $storage = $self->_storage;
679 my $signature = $storage->read_at( $subloc, SIG_SIZE );
682 # If value is a hash or array, return new DBM::Deep object with correct offset
684 if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) {
685 #XXX This needs to be a singleton
688 # if ( $signature eq SIG_HASH ) {
690 # tie %$new_obj, 'DBM::Deep', {
691 # base_offset => $subloc,
692 # storage => $self->_storage,
693 # parent => $self->{obj},
694 # parent_key => $orig_key,
696 # $is_autobless = tied(%$new_obj)->_storage->{autobless};
700 # tie @$new_obj, 'DBM::Deep', {
701 # base_offset => $subloc,
702 # storage => $self->_storage,
703 # parent => $self->{obj},
704 # parent_key => $orig_key,
706 # $is_autobless = tied(@$new_obj)->_storage->{autobless};
709 # if ($is_autobless) {
711 my $new_obj = DBM::Deep->new({
713 base_offset => $key_loc,
714 storage => $self->_storage,
715 parent => $self->{obj},
716 parent_key => $orig_key,
719 if ($new_obj->_storage->{autobless}) {
721 # Skip over value and plain key to see if object needs
724 $storage->increment_pointer( $self->{data_size} + $self->{index_size} );
726 my $size = $storage->read_at( undef, $self->{data_size} );
727 $size = unpack($self->{data_pack}, $size);
728 if ($size) { $storage->increment_pointer( $size ); }
730 my $bless_bit = $storage->read_at( undef, 1 );
731 if ( ord($bless_bit) ) {
734 $storage->read_at( undef, $self->{data_size} ),
738 $new_obj = bless $new_obj, $storage->read_at( undef, $size );
745 elsif ( $signature eq SIG_INTERNAL ) {
746 my $size = $storage->read_at( undef, $self->{data_size} );
747 $size = unpack($self->{data_pack}, $size);
750 my $new_loc = $storage->read_at( undef, $size );
751 $new_loc = unpack( $self->{long_pack}, $new_loc );
752 return $self->read_from_loc( $key_loc, $new_loc, $orig_key );
759 # Otherwise return actual value
761 elsif ( $signature eq SIG_DATA ) {
762 my $size = $storage->read_at( undef, $self->{data_size} );
763 $size = unpack($self->{data_pack}, $size);
765 my $value = $size ? $storage->read_at( undef, $size ) : '';
770 # Key exists, but content is null
775 sub get_bucket_value {
777 # Fetch single value given tag and MD5 digested key.
780 my ($tag, $md5, $orig_key) = @_;
782 #ACID - This is a read. Can find exact or HEAD
783 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
786 #XXX Need to use real key
787 # $self->add_bucket( $tag, $md5, $orig_key, undef, $orig_key );
790 # elsif ( !$is_deleted ) {
792 my $keytag = $self->load_tag( $keyloc );
793 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
794 if (!$subloc && !$is_deleted) {
795 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
797 if ( $subloc && !$is_deleted ) {
798 return $self->read_from_loc( $subloc, $orig_key );
807 # Delete single key/value pair given tag and MD5 digested key.
810 my ($tag, $md5, $orig_key) = @_;
812 #ACID - Although this is a mutation, we must find any transaction.
813 # This is because we need to mark something as deleted that is in the HEAD.
814 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
818 my $storage = $self->_storage;
821 if ( $storage->transaction_id == 0 ) {
822 @transactions = $storage->current_transactions;
825 if ( $storage->transaction_id == 0 ) {
826 my $keytag = $self->load_tag( $keyloc );
828 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
829 return if !$subloc || $is_deleted;
831 my $value = $self->read_from_loc( $subloc, $orig_key );
833 my $size = $self->_length_needed( $value, $orig_key );
835 for my $trans_id ( @transactions ) {
836 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
838 my $location2 = $storage->request_space( $size );
839 $storage->print_at( $keytag->{offset} + $offset2,
840 pack($self->{long_pack}, $location2 ),
841 pack( 'C C', $trans_id, 0 ),
843 $self->_write_value( $location2, $orig_key, $value, $orig_key );
847 $keytag = $self->load_tag( $keyloc );
848 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
849 $storage->print_at( $keytag->{offset} + $offset,
850 substr( $keytag->{content}, $offset + $self->{key_size} ),
851 chr(0) x $self->{key_size},
855 my $keytag = $self->load_tag( $keyloc );
857 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
859 $storage->print_at( $keytag->{offset} + $offset,
860 pack($self->{long_pack}, 0 ),
861 pack( 'C C', $storage->transaction_id, 1 ),
870 # Check existence of single key given tag and MD5 digested key.
873 my ($tag, $md5) = @_;
875 #ACID - This is a read. Can find exact or HEAD
876 my ($keyloc) = $self->_find_in_buckets( $tag, $md5 );
877 my $keytag = $self->load_tag( $keyloc );
878 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
879 if ( !$subloc && !$is_deleted ) {
880 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag, 0 );
882 return ($subloc && !$is_deleted) && 1;
887 # Locate offset for bucket list, given digested key
890 my ($offset, $md5, $args) = @_;
891 $args = {} unless $args;
894 # Locate offset for bucket list using digest index system
896 my $tag = $self->load_tag( $offset )
897 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
899 #XXX What happens when $ch >= $self->{hash_size} ??
900 for (my $ch = 0; $tag->{signature} ne SIG_BLIST; $ch++) {
901 my $num = ord substr($md5, $ch, 1);
903 my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
904 $tag = $self->index_lookup( $tag, $num );
907 return if !$args->{create};
909 my $loc = $self->_storage->request_space(
910 $self->tag_size( $self->{bucket_list_size} ),
913 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
915 $tag = $self->write_tag(
917 chr(0)x$self->{bucket_list_size},
920 $tag->{ref_loc} = $ref_loc;
927 $tag->{ref_loc} = $ref_loc;
935 # Given index tag, lookup single entry in index and return .
938 my ($tag, $index) = @_;
940 my $location = unpack(
944 $index * $self->{long_size},
949 if (!$location) { return; }
951 return $self->load_tag( $location );
956 # Scan index and recursively step into deeper levels, looking for next key.
959 my ($xxxx, $offset, $ch, $force_return_next) = @_;
961 my $tag = $self->load_tag( $offset );
963 if ($tag->{signature} ne SIG_BLIST) {
964 my $start = $xxxx->{return_next} ? 0 : ord(substr($xxxx->{prev_md5}, $ch, 1));
966 for (my $idx = $start; $idx < $self->{hash_chars_used}; $idx++) {
971 $idx * $self->{long_size},
977 my $result = $self->traverse_index(
978 $xxxx, $subloc, $ch + 1, $force_return_next,
981 if (defined $result) { return $result; }
985 $xxxx->{return_next} = 1;
987 # This is the bucket list
989 my $keys = $tag->{content};
990 if ($force_return_next) { $xxxx->{return_next} = 1; }
993 # Iterate through buckets, looking for a key match
995 my $transaction_id = $self->_storage->transaction_id;
996 for (my $i = 0; $i < $self->{max_buckets}; $i++) {
997 my ($key, $keyloc) = $self->_get_key_subloc( $keys, $i );
999 # End of bucket list -- return to outer loop
1001 $xxxx->{return_next} = 1;
1004 # Located previous key -- return next one found
1005 elsif ($key eq $xxxx->{prev_md5}) {
1006 $xxxx->{return_next} = 1;
1009 # Seek to bucket location and skip over signature
1010 elsif ($xxxx->{return_next}) {
1011 my $storage = $self->_storage;
1013 my $keytag = $self->load_tag( $keyloc );
1014 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
1015 if ( $subloc == 0 && !$is_deleted ) {
1016 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
1018 next if $is_deleted;
1020 # Skip over value to get to plain key
1021 my $sig = $storage->read_at( $subloc, SIG_SIZE );
1023 my $size = $storage->read_at( undef, $self->{data_size} );
1024 $size = unpack($self->{data_pack}, $size);
1025 if ($size) { $storage->increment_pointer( $size ); }
1027 # Read in plain key and return as scalar
1028 $size = $storage->read_at( undef, $self->{data_size} );
1029 $size = unpack($self->{data_pack}, $size);
1032 if ($size) { $plain_key = $storage->read_at( undef, $size); }
1037 $xxxx->{return_next} = 1;
1045 sub _get_key_subloc {
1047 my ($keys, $idx) = @_;
1050 # This is 'a', not 'A'. Please read the pack() documentation for the
1051 # difference between the two and why it's important.
1052 "a$self->{hash_size} $self->{long_pack}",
1055 ($idx * $self->{bucket_size}),
1056 $self->{bucket_size},
1061 sub _find_in_buckets {
1063 my ($tag, $md5) = @_;
1066 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
1067 my ($key, $subloc) = $self->_get_key_subloc(
1068 $tag->{content}, $i,
1071 next BUCKET if $subloc && $key ne $md5;
1072 return( $subloc, $i * $self->{bucket_size} );
1078 sub _release_space {
1080 my ($size, $loc) = @_;
1084 $self->_storage->print_at( $loc,
1086 pack($self->{long_pack}, $size ),
1087 pack($self->{long_pack}, $next_loc ),
1094 die "DBM::Deep: $_[1]\n";
1097 sub _get_dbm_object {
1101 local $SIG{__DIE__};
1102 if ($item->isa( 'DBM::Deep' )) {
1107 return $obj if $obj;
1109 my $r = Scalar::Util::reftype( $item ) || '';
1110 if ( $r eq 'HASH' ) {
1112 local $SIG{__DIE__};
1113 my $obj = tied(%$item);
1114 if ($obj->isa( 'DBM::Deep' )) {
1119 return $obj if $obj;
1121 elsif ( $r eq 'ARRAY' ) {
1123 local $SIG{__DIE__};
1124 my $obj = tied(@$item);
1125 if ($obj->isa( 'DBM::Deep' )) {
1130 return $obj if $obj;
1136 sub _length_needed {
1138 my ($value, $key) = @_;
1140 my $is_dbm_deep = eval {
1141 local $SIG{'__DIE__'};
1142 $value->isa( 'DBM::Deep' );
1146 + $self->{data_size} # size for value
1147 + $self->{data_size} # size for key
1148 + length( $key ); # length of key
1150 if ( $is_dbm_deep && $value->_storage eq $self->_storage ) {
1151 # long_size is for the internal reference
1152 return $len + $self->{long_size};
1155 if ( $self->_storage->{autobless} ) {
1156 # This is for the bit saying whether or not this thing is blessed.
1160 my $r = Scalar::Util::reftype( $value ) || '';
1161 unless ( $r eq 'HASH' || $r eq 'ARRAY' ) {
1162 if ( defined $value ) {
1163 $len += length( $value );
1168 $len += $self->{index_size};
1170 # if autobless is enabled, must also take into consideration
1171 # the class name as it is stored after the key.
1172 if ( $self->_storage->{autobless} ) {
1173 my $c = Scalar::Util::blessed($value);
1174 if ( defined $c && !$is_dbm_deep ) {
1175 $len += $self->{data_size} + length($c);