1 package DBM::Deep::Engine;
8 our $VERSION = q(0.99_03);
10 use Fcntl qw( :DEFAULT :flock );
14 # * To add to bucket_size, make sure you modify the following:
17 # - add_bucket() - where the buckets are printed
19 # * Every method in here assumes that the _storage has been appropriately
20 # safeguarded. This can be anything from flock() to some sort of manual
21 # mutex. But, it's the caller's responsability to make sure that this has
25 # Setup file and tag signatures. These should never change.
27 sub SIG_FILE () { 'DPDB' }
28 sub SIG_HEADER () { 'h' }
29 sub SIG_INTERNAL () { 'i' }
30 sub SIG_HASH () { 'H' }
31 sub SIG_ARRAY () { 'A' }
32 sub SIG_NULL () { 'N' }
33 sub SIG_DATA () { 'D' }
34 sub SIG_INDEX () { 'I' }
35 sub SIG_BLIST () { 'B' }
36 sub SIG_FREE () { 'F' }
37 sub SIG_KEYS () { 'K' }
40 # This is the transaction ID for the HEAD
43 ################################################################################
45 # This is new code. It is a complete rewrite of the engine based on a new API
47 ################################################################################
51 my ($trans_id, $offset, $key, $orig_key) = @_;
53 my $dig_key = $self->_apply_digest( $key );
54 my $tag = $self->find_blist( $offset, $dig_key ) or return;
55 return $self->get_bucket_value( $tag, $dig_key, $orig_key );
60 my ($trans_id, $offset, $key) = @_;
62 my $dig_key = $self->_apply_digest( $key );
63 # exists() returns the empty string, not undef
64 my $tag = $self->find_blist( $offset, $dig_key ) or return '';
65 return $self->bucket_exists( $tag, $dig_key, $key );
70 my ($trans_id, $offset) = @_;
72 # If the previous key was not specifed, start at the top and
73 # return the first one found.
77 prev_md5 => $self->_apply_digest($_[2]),
83 prev_md5 => chr(0) x $self->{hash_size},
88 return $self->traverse_index( $temp, $offset, 0 );
93 my ($trans_id, $offset, $key, $orig_key) = @_;
95 my $dig_key = $self->_apply_digest( $key );
96 my $tag = $self->find_blist( $offset, $dig_key ) or return;
97 my $value = $self->get_bucket_value( $tag, $dig_key, $orig_key );
98 $self->delete_bucket( $tag, $dig_key, $orig_key );
104 my ($trans_id, $offset, $key, $value, $orig_key) = @_;
106 my $dig_key = $self->_apply_digest( $key );
107 my $tag = $self->find_blist( $offset, $dig_key, { create => 1 } );
108 return $self->add_bucket( $tag, $dig_key, $key, $value, undef, $orig_key );
111 ################################################################################
113 # Below here is the old code. It will be folded into the code above as it can.
115 ################################################################################
127 digest => \&Digest::MD5::md5,
128 hash_size => 16, # In bytes
131 # Number of buckets per blist before another level of indexing is
132 # done. Increase this value for slightly greater speed, but larger database
133 # files. DO NOT decrease this value below 16, due to risk of recursive
142 if ( defined $args->{pack_size} ) {
143 if ( lc $args->{pack_size} eq 'small' ) {
144 $args->{long_size} = 2;
145 $args->{long_pack} = 'n';
147 elsif ( lc $args->{pack_size} eq 'medium' ) {
148 $args->{long_size} = 4;
149 $args->{long_pack} = 'N';
151 elsif ( lc $args->{pack_size} eq 'large' ) {
152 $args->{long_size} = 8;
153 $args->{long_pack} = 'Q';
156 die "Unknown pack_size value: '$args->{pack_size}'\n";
160 # Grab the parameters we want to use
161 foreach my $param ( keys %$self ) {
162 next unless exists $args->{$param};
163 $self->{$param} = $args->{$param};
165 Scalar::Util::weaken( $self->{obj} ) if $self->{obj};
167 if ( $self->{max_buckets} < 16 ) {
168 warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n";
169 $self->{max_buckets} = 16;
175 sub _storage { return $_[0]{storage} }
179 return $self->{digest}->(@_);
182 sub calculate_sizes {
185 # The 2**8 here indicates the number of different characters in the
186 # current hashing algorithm
187 #XXX Does this need to be updated with different hashing algorithms?
188 $self->{hash_chars_used} = (2**8);
189 $self->{index_size} = $self->{hash_chars_used} * $self->{long_size};
191 $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2;
192 $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
194 $self->{key_size} = $self->{long_size} * 2;
195 $self->{keyloc_size} = $self->{max_buckets} * $self->{key_size};
200 sub write_file_header {
203 my $loc = $self->_storage->request_space( length( SIG_FILE ) + 33 );
205 $self->_storage->print_at( $loc,
208 pack('N', 1), # header version
209 pack('N', 24), # header size
210 pack('N4', 0, 0, 0, 0), # currently running transaction IDs
211 pack('n', $self->{long_size}),
212 pack('A', $self->{long_pack}),
213 pack('n', $self->{data_size}),
214 pack('A', $self->{data_pack}),
215 pack('n', $self->{max_buckets}),
218 $self->_storage->set_transaction_offset( 13 );
223 sub read_file_header {
226 my $buffer = $self->_storage->read_at( 0, length(SIG_FILE) + 9 );
227 return unless length($buffer);
229 my ($file_signature, $sig_header, $header_version, $size) = unpack(
233 unless ( $file_signature eq SIG_FILE ) {
234 $self->_storage->close;
235 $self->_throw_error( "Signature not found -- file is not a Deep DB" );
238 unless ( $sig_header eq SIG_HEADER ) {
239 $self->_storage->close;
240 $self->_throw_error( "Old file version found." );
243 my $buffer2 = $self->_storage->read_at( undef, $size );
244 my ($a1, $a2, $a3, $a4, @values) = unpack( 'N4 n A n A n', $buffer2 );
246 $self->_storage->set_transaction_offset( 13 );
248 if ( @values < 5 || grep { !defined } @values ) {
249 $self->_storage->close;
250 $self->_throw_error("Corrupted file - bad header");
253 #XXX Add warnings if values weren't set right
254 @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values;
256 return length($buffer) + length($buffer2);
263 # Need to remove use of $fh here
264 my $fh = $self->_storage->{fh};
267 #XXX The duplication of calculate_sizes needs to go away
268 unless ( $obj->{base_offset} ) {
269 my $bytes_read = $self->read_file_header;
271 $self->calculate_sizes;
274 # File is empty -- write header and master index
277 $self->_storage->audit( "# Database created on" );
279 $self->write_file_header;
281 $obj->{base_offset} = $self->_storage->request_space(
282 $self->tag_size( $self->{index_size} ),
286 $obj->_base_offset, $obj->_type,
287 chr(0)x$self->{index_size},
290 # Flush the filehandle
291 my $old_fh = select $fh;
292 my $old_af = $|; $| = 1; $| = $old_af;
296 $obj->{base_offset} = $bytes_read;
299 # Get our type from master index header
301 my $tag = $self->load_tag($obj->_base_offset);
304 $self->_throw_error("Corrupted file, no master index record");
307 unless ($obj->_type eq $tag->{signature}) {
309 $self->_throw_error("File type mismatch");
314 $self->calculate_sizes;
317 #XXX We have to make sure we don't mess up when autoflush isn't turned on
318 $self->_storage->set_inode;
328 return SIG_SIZE + $self->{data_size} + $size;
333 # Given offset, signature and content, create tag and write to disk
336 my ($offset, $sig, $content) = @_;
337 my $size = length( $content );
339 $self->_storage->print_at(
341 $sig, pack($self->{data_pack}, $size), $content,
344 return unless defined $offset;
348 #XXX Is this even used?
350 offset => $offset + SIG_SIZE + $self->{data_size},
357 # Given offset, load single tag and return signature, size and data
362 my $storage = $self->_storage;
364 my ($sig, $size) = unpack(
365 "A $self->{data_pack}",
366 $storage->read_at( $offset, SIG_SIZE + $self->{data_size} ),
371 size => $size, #XXX Is this even used?
373 offset => $offset + SIG_SIZE + $self->{data_size},
374 content => $storage->read_at( undef, $size ),
380 my ($tag, $transaction_id) = @_;
381 $transaction_id = $self->_storage->transaction_id
382 unless defined $transaction_id;
384 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
385 my ($loc, $trans_id, $is_deleted) = unpack(
386 "$self->{long_pack} C C",
387 substr( $tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
390 next if $loc != HEAD && $transaction_id != $trans_id;
391 return( $loc, $is_deleted, $i * $self->{key_size} );
399 # Adds one key/value pair to bucket list, given offset, MD5 digest of key,
400 # plain (undigested) key and value.
403 my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_;
405 # This verifies that only supported values will be stored.
407 my $r = Scalar::Util::reftype( $value );
410 last if $r eq 'HASH';
411 last if $r eq 'ARRAY';
414 "Storage of references of type '$r' is not supported."
418 my $storage = $self->_storage;
420 #ACID - This is a mutation. Must only find the exact transaction
421 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5, 1 );
424 if ( $storage->transaction_id == 0 ) {
425 @transactions = $storage->current_transactions;
428 # $self->_release_space( $size, $subloc );
429 #XXX This needs updating to use _release_space
432 my $size = $self->_length_needed( $value, $plain_key );
434 # Updating a known md5
436 my $keytag = $self->load_tag( $keyloc );
437 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
439 if ( $subloc && !$is_deleted && @transactions ) {
440 my $old_value = $self->read_from_loc( $subloc, $orig_key );
441 my $old_size = $self->_length_needed( $old_value, $plain_key );
443 for my $trans_id ( @transactions ) {
444 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
446 my $location2 = $storage->request_space( $old_size );
447 $storage->print_at( $keytag->{offset} + $offset2,
448 pack($self->{long_pack}, $location2 ),
449 pack( 'C C', $trans_id, 0 ),
451 $self->_write_value( $location2, $plain_key, $old_value, $orig_key );
456 $location = $self->_storage->request_space( $size );
457 #XXX This needs to be transactionally-aware in terms of which keytag->{offset} to use
458 $storage->print_at( $keytag->{offset} + $offset,
459 pack($self->{long_pack}, $location ),
460 pack( 'C C', $storage->transaction_id, 0 ),
465 my $keyloc = $storage->request_space( $self->tag_size( $self->{keyloc_size} ) );
467 # The bucket fit into list
468 if ( defined $offset ) {
469 $storage->print_at( $tag->{offset} + $offset,
470 $md5, pack( $self->{long_pack}, $keyloc ),
473 # If bucket didn't fit into list, split into a new index level
475 $self->split_index( $tag, $md5, $keyloc );
478 my $keytag = $self->write_tag(
479 $keyloc, SIG_KEYS, chr(0)x$self->{keyloc_size},
482 $location = $self->_storage->request_space( $size );
483 $storage->print_at( $keytag->{offset},
484 pack( $self->{long_pack}, $location ),
485 pack( 'C C', $storage->transaction_id, 0 ),
489 for my $trans_id ( @transactions ) {
490 $storage->print_at( $keytag->{offset} + $self->{key_size} * $offset++,
491 pack( $self->{long_pack}, 0 ),
492 pack( 'C C', $trans_id, 1 ),
497 $self->_write_value( $location, $plain_key, $value, $orig_key );
504 my ($location, $key, $value, $orig_key) = @_;
506 my $storage = $self->_storage;
508 my $dbm_deep_obj = _get_dbm_object( $value );
509 if ( $dbm_deep_obj && $dbm_deep_obj->_storage ne $storage ) {
510 $self->_throw_error( "Cannot cross-reference. Use export() instead" );
514 # Write signature based on content type, set content length and write
517 my $r = Scalar::Util::reftype( $value ) || '';
518 if ( $dbm_deep_obj ) {
519 $self->write_tag( $location, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) );
521 elsif ($r eq 'HASH') {
522 if ( !$dbm_deep_obj && tied %{$value} ) {
523 $self->_throw_error( "Cannot store something that is tied" );
525 $self->write_tag( $location, SIG_HASH, chr(0)x$self->{index_size} );
527 elsif ($r eq 'ARRAY') {
528 if ( !$dbm_deep_obj && tied @{$value} ) {
529 $self->_throw_error( "Cannot store something that is tied" );
531 $self->write_tag( $location, SIG_ARRAY, chr(0)x$self->{index_size} );
533 elsif (!defined($value)) {
534 $self->write_tag( $location, SIG_NULL, '' );
537 $self->write_tag( $location, SIG_DATA, $value );
541 # Plain key is stored AFTER value, as keys are typically fetched less often.
543 $storage->print_at( undef, pack($self->{data_pack}, length($key)) . $key );
545 # Internal references don't care about autobless
546 return 1 if $dbm_deep_obj;
549 # If value is blessed, preserve class name
551 if ( $storage->{autobless} ) {
552 if ( defined( my $c = Scalar::Util::blessed($value) ) ) {
553 $storage->print_at( undef, chr(1), pack($self->{data_pack}, length($c)) . $c );
556 $storage->print_at( undef, chr(0) );
561 # Tie the passed in reference so that changes to it are reflected in the
562 # datafile. The use of $location as the base_offset will act as the
563 # the linkage between parent and child.
565 # The overall assignment is a hack around the fact that just tying doesn't
566 # store the values. This may not be the wrong thing to do.
570 tie %$value, 'DBM::Deep', {
571 base_offset => $location,
573 parent => $self->{obj},
574 parent_key => $orig_key,
577 bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value );
579 elsif ($r eq 'ARRAY') {
581 tie @$value, 'DBM::Deep', {
582 base_offset => $location,
584 parent => $self->{obj},
585 parent_key => $orig_key,
588 bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value );
596 my ($tag, $md5, $keyloc) = @_;
598 my $storage = $self->_storage;
600 my $loc = $storage->request_space(
601 $self->tag_size( $self->{index_size} ),
604 $storage->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) );
606 my $index_tag = $self->write_tag(
608 chr(0)x$self->{index_size},
611 my $keys = $tag->{content}
612 . $md5 . pack($self->{long_pack}, $keyloc);
616 # The <= here is deliberate - we have max_buckets+1 keys to iterate
617 # through, unlike every other loop that uses max_buckets as a stop.
618 for (my $i = 0; $i <= $self->{max_buckets}; $i++) {
619 my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i );
621 die "[INTERNAL ERROR]: No key in split_index()\n" unless $key;
622 die "[INTERNAL ERROR]: No subloc in split_index()\n" unless $old_subloc;
624 my $num = ord(substr($key, $tag->{ch} + 1, 1));
627 my $subkeys = $storage->read_at( $newloc[$num], $self->{bucket_list_size} );
629 # This is looking for the first empty spot
630 my ($subloc, $offset) = $self->_find_in_buckets(
631 { content => $subkeys }, '',
635 $newloc[$num] + $offset,
636 $key, pack($self->{long_pack}, $old_subloc),
642 my $loc = $storage->request_space(
643 $self->tag_size( $self->{bucket_list_size} ),
647 $index_tag->{offset} + ($num * $self->{long_size}),
648 pack($self->{long_pack}, $loc),
651 my $blist_tag = $self->write_tag(
653 chr(0)x$self->{bucket_list_size},
656 $storage->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) );
658 $newloc[$num] = $blist_tag->{offset};
661 $self->_release_space(
662 $self->tag_size( $self->{bucket_list_size} ),
671 my ($subloc, $orig_key) = @_;
673 my $storage = $self->_storage;
675 my $signature = $storage->read_at( $subloc, SIG_SIZE );
678 # If value is a hash or array, return new DBM::Deep object with correct offset
680 if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) {
681 #XXX This needs to be a singleton
684 # if ( $signature eq SIG_HASH ) {
686 # tie %$new_obj, 'DBM::Deep', {
687 # base_offset => $subloc,
688 # storage => $self->_storage,
689 # parent => $self->{obj},
690 # parent_key => $orig_key,
692 # $is_autobless = tied(%$new_obj)->_storage->{autobless};
696 # tie @$new_obj, 'DBM::Deep', {
697 # base_offset => $subloc,
698 # storage => $self->_storage,
699 # parent => $self->{obj},
700 # parent_key => $orig_key,
702 # $is_autobless = tied(@$new_obj)->_storage->{autobless};
705 # if ($is_autobless) {
707 my $new_obj = DBM::Deep->new({
709 base_offset => $subloc,
710 storage => $self->_storage,
711 parent => $self->{obj},
712 parent_key => $orig_key,
715 if ($new_obj->_storage->{autobless}) {
717 # Skip over value and plain key to see if object needs
720 $storage->increment_pointer( $self->{data_size} + $self->{index_size} );
722 my $size = $storage->read_at( undef, $self->{data_size} );
723 $size = unpack($self->{data_pack}, $size);
724 if ($size) { $storage->increment_pointer( $size ); }
726 my $bless_bit = $storage->read_at( undef, 1 );
727 if ( ord($bless_bit) ) {
730 $storage->read_at( undef, $self->{data_size} ),
734 $new_obj = bless $new_obj, $storage->read_at( undef, $size );
741 elsif ( $signature eq SIG_INTERNAL ) {
742 my $size = $storage->read_at( undef, $self->{data_size} );
743 $size = unpack($self->{data_pack}, $size);
746 my $new_loc = $storage->read_at( undef, $size );
747 $new_loc = unpack( $self->{long_pack}, $new_loc );
748 return $self->read_from_loc( $new_loc, $orig_key );
755 # Otherwise return actual value
757 elsif ( $signature eq SIG_DATA ) {
758 my $size = $storage->read_at( undef, $self->{data_size} );
759 $size = unpack($self->{data_pack}, $size);
761 my $value = $size ? $storage->read_at( undef, $size ) : '';
766 # Key exists, but content is null
771 sub get_bucket_value {
773 # Fetch single value given tag and MD5 digested key.
776 my ($tag, $md5, $orig_key) = @_;
778 #ACID - This is a read. Can find exact or HEAD
779 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
782 #XXX Need to use real key
783 # $self->add_bucket( $tag, $md5, $orig_key, undef, $orig_key );
786 # elsif ( !$is_deleted ) {
788 my $keytag = $self->load_tag( $keyloc );
789 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
790 if (!$subloc && !$is_deleted) {
791 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
793 if ( $subloc && !$is_deleted ) {
794 return $self->read_from_loc( $subloc, $orig_key );
803 # Delete single key/value pair given tag and MD5 digested key.
806 my ($tag, $md5, $orig_key) = @_;
808 #ACID - Although this is a mutation, we must find any transaction.
809 # This is because we need to mark something as deleted that is in the HEAD.
810 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
814 my $storage = $self->_storage;
817 if ( $storage->transaction_id == 0 ) {
818 @transactions = $storage->current_transactions;
821 if ( $storage->transaction_id == 0 ) {
822 my $keytag = $self->load_tag( $keyloc );
824 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
825 return if !$subloc || $is_deleted;
827 my $value = $self->read_from_loc( $subloc, $orig_key );
829 my $size = $self->_length_needed( $value, $orig_key );
831 for my $trans_id ( @transactions ) {
832 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
834 my $location2 = $storage->request_space( $size );
835 $storage->print_at( $keytag->{offset} + $offset2,
836 pack($self->{long_pack}, $location2 ),
837 pack( 'C C', $trans_id, 0 ),
839 $self->_write_value( $location2, $orig_key, $value, $orig_key );
843 $keytag = $self->load_tag( $keyloc );
844 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
845 $storage->print_at( $keytag->{offset} + $offset,
846 substr( $keytag->{content}, $offset + $self->{key_size} ),
847 chr(0) x $self->{key_size},
851 my $keytag = $self->load_tag( $keyloc );
853 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
855 $storage->print_at( $keytag->{offset} + $offset,
856 pack($self->{long_pack}, 0 ),
857 pack( 'C C', $storage->transaction_id, 1 ),
866 # Check existence of single key given tag and MD5 digested key.
869 my ($tag, $md5) = @_;
871 #ACID - This is a read. Can find exact or HEAD
872 my ($keyloc) = $self->_find_in_buckets( $tag, $md5 );
873 my $keytag = $self->load_tag( $keyloc );
874 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
875 if ( !$subloc && !$is_deleted ) {
876 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag, 0 );
878 return ($subloc && !$is_deleted) && 1;
883 # Locate offset for bucket list, given digested key
886 my ($offset, $md5, $args) = @_;
887 $args = {} unless $args;
890 # Locate offset for bucket list using digest index system
892 my $tag = $self->load_tag( $offset )
893 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
895 #XXX What happens when $ch >= $self->{hash_size} ??
896 for (my $ch = 0; $tag->{signature} ne SIG_BLIST; $ch++) {
897 my $num = ord substr($md5, $ch, 1);
899 my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
900 $tag = $self->index_lookup( $tag, $num );
903 return if !$args->{create};
905 my $loc = $self->_storage->request_space(
906 $self->tag_size( $self->{bucket_list_size} ),
909 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
911 $tag = $self->write_tag(
913 chr(0)x$self->{bucket_list_size},
916 $tag->{ref_loc} = $ref_loc;
923 $tag->{ref_loc} = $ref_loc;
931 # Given index tag, lookup single entry in index and return .
934 my ($tag, $index) = @_;
936 my $location = unpack(
940 $index * $self->{long_size},
945 if (!$location) { return; }
947 return $self->load_tag( $location );
952 # Scan index and recursively step into deeper levels, looking for next key.
955 my ($xxxx, $offset, $ch, $force_return_next) = @_;
957 my $tag = $self->load_tag( $offset );
959 if ($tag->{signature} ne SIG_BLIST) {
960 my $start = $xxxx->{return_next} ? 0 : ord(substr($xxxx->{prev_md5}, $ch, 1));
962 for (my $idx = $start; $idx < $self->{hash_chars_used}; $idx++) {
967 $idx * $self->{long_size},
973 my $result = $self->traverse_index(
974 $xxxx, $subloc, $ch + 1, $force_return_next,
977 if (defined $result) { return $result; }
981 $xxxx->{return_next} = 1;
983 # This is the bucket list
985 my $keys = $tag->{content};
986 if ($force_return_next) { $xxxx->{return_next} = 1; }
989 # Iterate through buckets, looking for a key match
991 my $transaction_id = $self->_storage->transaction_id;
992 for (my $i = 0; $i < $self->{max_buckets}; $i++) {
993 my ($key, $keyloc) = $self->_get_key_subloc( $keys, $i );
995 # End of bucket list -- return to outer loop
997 $xxxx->{return_next} = 1;
1000 # Located previous key -- return next one found
1001 elsif ($key eq $xxxx->{prev_md5}) {
1002 $xxxx->{return_next} = 1;
1005 # Seek to bucket location and skip over signature
1006 elsif ($xxxx->{return_next}) {
1007 my $storage = $self->_storage;
1009 my $keytag = $self->load_tag( $keyloc );
1010 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
1011 if ( $subloc == 0 && !$is_deleted ) {
1012 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
1014 next if $is_deleted;
1016 # Skip over value to get to plain key
1017 my $sig = $storage->read_at( $subloc, SIG_SIZE );
1019 my $size = $storage->read_at( undef, $self->{data_size} );
1020 $size = unpack($self->{data_pack}, $size);
1021 if ($size) { $storage->increment_pointer( $size ); }
1023 # Read in plain key and return as scalar
1024 $size = $storage->read_at( undef, $self->{data_size} );
1025 $size = unpack($self->{data_pack}, $size);
1028 if ($size) { $plain_key = $storage->read_at( undef, $size); }
1033 $xxxx->{return_next} = 1;
1041 sub _get_key_subloc {
1043 my ($keys, $idx) = @_;
1046 # This is 'a', not 'A'. Please read the pack() documentation for the
1047 # difference between the two and why it's important.
1048 "a$self->{hash_size} $self->{long_pack}",
1051 ($idx * $self->{bucket_size}),
1052 $self->{bucket_size},
1057 sub _find_in_buckets {
1059 my ($tag, $md5) = @_;
1062 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
1063 my ($key, $subloc) = $self->_get_key_subloc(
1064 $tag->{content}, $i,
1067 next BUCKET if $subloc && $key ne $md5;
1068 return( $subloc, $i * $self->{bucket_size} );
1074 sub _release_space {
1076 my ($size, $loc) = @_;
1080 $self->_storage->print_at( $loc,
1082 pack($self->{long_pack}, $size ),
1083 pack($self->{long_pack}, $next_loc ),
1090 die "DBM::Deep: $_[1]\n";
1093 sub _get_dbm_object {
1097 local $SIG{__DIE__};
1098 if ($item->isa( 'DBM::Deep' )) {
1103 return $obj if $obj;
1105 my $r = Scalar::Util::reftype( $item ) || '';
1106 if ( $r eq 'HASH' ) {
1108 local $SIG{__DIE__};
1109 my $obj = tied(%$item);
1110 if ($obj->isa( 'DBM::Deep' )) {
1115 return $obj if $obj;
1117 elsif ( $r eq 'ARRAY' ) {
1119 local $SIG{__DIE__};
1120 my $obj = tied(@$item);
1121 if ($obj->isa( 'DBM::Deep' )) {
1126 return $obj if $obj;
1132 sub _length_needed {
1134 my ($value, $key) = @_;
1136 my $is_dbm_deep = eval {
1137 local $SIG{'__DIE__'};
1138 $value->isa( 'DBM::Deep' );
1142 + $self->{data_size} # size for value
1143 + $self->{data_size} # size for key
1144 + length( $key ); # length of key
1146 if ( $is_dbm_deep && $value->_storage eq $self->_storage ) {
1147 # long_size is for the internal reference
1148 return $len + $self->{long_size};
1151 if ( $self->_storage->{autobless} ) {
1152 # This is for the bit saying whether or not this thing is blessed.
1156 my $r = Scalar::Util::reftype( $value ) || '';
1157 unless ( $r eq 'HASH' || $r eq 'ARRAY' ) {
1158 if ( defined $value ) {
1159 $len += length( $value );
1164 $len += $self->{index_size};
1166 # if autobless is enabled, must also take into consideration
1167 # the class name as it is stored after the key.
1168 if ( $self->_storage->{autobless} ) {
1169 my $c = Scalar::Util::blessed($value);
1170 if ( defined $c && !$is_dbm_deep ) {
1171 $len += $self->{data_size} + length($c);