1 package DBM::Deep::Engine;
7 our $VERSION = q(0.99_03);
9 use Fcntl qw( :DEFAULT :flock );
13 # * To add to bucket_size, make sure you modify the following:
16 # - add_bucket() - where the buckets are printed
18 # * Every method in here assumes that the _storage has been appropriately
19 # safeguarded. This can be anything from flock() to some sort of manual
20 # mutex. But, it's the caller's responsability to make sure that this has
24 # Setup file and tag signatures. These should never change.
26 sub SIG_FILE () { 'DPDB' }
27 sub SIG_HEADER () { 'h' }
28 sub SIG_INTERNAL () { 'i' }
29 sub SIG_HASH () { 'H' }
30 sub SIG_ARRAY () { 'A' }
31 sub SIG_NULL () { 'N' }
32 sub SIG_DATA () { 'D' }
33 sub SIG_INDEX () { 'I' }
34 sub SIG_BLIST () { 'B' }
35 sub SIG_FREE () { 'F' }
36 sub SIG_KEYS () { 'K' }
39 # This is the transaction ID for the HEAD
42 ################################################################################
44 # This is new code. It is a complete rewrite of the engine based on a new API
46 ################################################################################
50 my ($trans_id, $offset, $key, $orig_key) = @_;
52 my $dig_key = $self->_apply_digest( $key );
53 my $tag = $self->find_blist( $offset, $dig_key ) or return;
54 return $self->get_bucket_value( $tag, $dig_key, $orig_key );
59 my ($trans_id, $offset, $key) = @_;
61 my $dig_key = $self->_apply_digest( $key );
62 # exists() returns the empty string, not undef
63 my $tag = $self->find_blist( $offset, $dig_key ) or return '';
64 return $self->bucket_exists( $tag, $dig_key, $key );
70 my ($trans_id, $base_offset, $key) = @_;
72 my ($_val_offset, $_is_del) = $self->_find_value_offset({
73 offset => $base_offset,
74 trans_id => $trans_id,
77 die "Attempt to use a deleted value" if $_is_del;
78 die "Internal error!" if !$_val_offset;
80 my ($key_offset) = $self->_find_key_offset({
81 offset => $_val_offset,
82 key_md5 => $self->_apply_digest( $key ),
85 return if !$key_offset;
87 my ($val_offset, $is_del) = $self->_find_value_offset({
88 offset => $key_offset,
89 trans_id => $trans_id,
95 die "Internal error!" if !$_val_offset;
102 my ($trans_id, $offset) = @_;
104 # If the previous key was not specifed, start at the top and
105 # return the first one found.
109 prev_md5 => $self->_apply_digest($_[2]),
115 prev_md5 => chr(0) x $self->{hash_size},
120 return $self->traverse_index( $temp, $offset, 0 );
125 my ($trans_id, $offset, $key, $orig_key) = @_;
127 my $dig_key = $self->_apply_digest( $key );
128 my $tag = $self->find_blist( $offset, $dig_key ) or return;
129 my $value = $self->get_bucket_value( $tag, $dig_key, $orig_key );
130 $self->delete_bucket( $tag, $dig_key, $orig_key );
136 my ($trans_id, $offset, $key, $value, $orig_key) = @_;
138 my $dig_key = $self->_apply_digest( $key );
139 my $tag = $self->find_blist( $offset, $dig_key, { create => 1 } );
140 return $self->add_bucket( $tag, $dig_key, $key, $value, undef, $orig_key );
143 ################################################################################
145 # Below here is the old code. It will be folded into the code above as it can.
147 ################################################################################
159 digest => \&Digest::MD5::md5,
160 hash_size => 16, # In bytes
163 # Number of buckets per blist before another level of indexing is
164 # done. Increase this value for slightly greater speed, but larger database
165 # files. DO NOT decrease this value below 16, due to risk of recursive
174 if ( defined $args->{pack_size} ) {
175 if ( lc $args->{pack_size} eq 'small' ) {
176 $args->{long_size} = 2;
177 $args->{long_pack} = 'n';
179 elsif ( lc $args->{pack_size} eq 'medium' ) {
180 $args->{long_size} = 4;
181 $args->{long_pack} = 'N';
183 elsif ( lc $args->{pack_size} eq 'large' ) {
184 $args->{long_size} = 8;
185 $args->{long_pack} = 'Q';
188 die "Unknown pack_size value: '$args->{pack_size}'\n";
192 # Grab the parameters we want to use
193 foreach my $param ( keys %$self ) {
194 next unless exists $args->{$param};
195 $self->{$param} = $args->{$param};
197 Scalar::Util::weaken( $self->{obj} ) if $self->{obj};
199 if ( $self->{max_buckets} < 16 ) {
200 warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n";
201 $self->{max_buckets} = 16;
207 sub _storage { return $_[0]{storage} }
211 return $self->{digest}->(@_);
214 sub calculate_sizes {
217 # The 2**8 here indicates the number of different characters in the
218 # current hashing algorithm
219 #XXX Does this need to be updated with different hashing algorithms?
220 $self->{hash_chars_used} = (2**8);
221 $self->{index_size} = $self->{hash_chars_used} * $self->{long_size};
223 $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2;
224 $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
226 $self->{key_size} = $self->{long_size} * 2;
227 $self->{keyloc_size} = $self->{max_buckets} * $self->{key_size};
232 sub write_file_header {
235 my $loc = $self->_storage->request_space( length( SIG_FILE ) + 33 );
237 $self->_storage->print_at( $loc,
240 pack('N', 1), # header version
241 pack('N', 24), # header size
242 pack('N4', 0, 0, 0, 0), # currently running transaction IDs
243 pack('n', $self->{long_size}),
244 pack('A', $self->{long_pack}),
245 pack('n', $self->{data_size}),
246 pack('A', $self->{data_pack}),
247 pack('n', $self->{max_buckets}),
250 $self->_storage->set_transaction_offset( 13 );
255 sub read_file_header {
258 my $buffer = $self->_storage->read_at( 0, length(SIG_FILE) + 9 );
259 return unless length($buffer);
261 my ($file_signature, $sig_header, $header_version, $size) = unpack(
265 unless ( $file_signature eq SIG_FILE ) {
266 $self->_storage->close;
267 $self->_throw_error( "Signature not found -- file is not a Deep DB" );
270 unless ( $sig_header eq SIG_HEADER ) {
271 $self->_storage->close;
272 $self->_throw_error( "Old file version found." );
275 my $buffer2 = $self->_storage->read_at( undef, $size );
276 my ($a1, $a2, $a3, $a4, @values) = unpack( 'N4 n A n A n', $buffer2 );
278 $self->_storage->set_transaction_offset( 13 );
280 if ( @values < 5 || grep { !defined } @values ) {
281 $self->_storage->close;
282 $self->_throw_error("Corrupted file - bad header");
285 #XXX Add warnings if values weren't set right
286 @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values;
288 return length($buffer) + length($buffer2);
295 # Need to remove use of $fh here
296 my $fh = $self->_storage->{fh};
299 #XXX The duplication of calculate_sizes needs to go away
300 unless ( $obj->{base_offset} ) {
301 my $bytes_read = $self->read_file_header;
303 $self->calculate_sizes;
306 # File is empty -- write header and master index
309 $self->_storage->audit( "# Database created on" );
311 $self->write_file_header;
313 $obj->{base_offset} = $self->_storage->request_space(
314 $self->tag_size( $self->{index_size} ),
318 $obj->_base_offset, $obj->_type,
319 chr(0)x$self->{index_size},
322 # Flush the filehandle
323 my $old_fh = select $fh;
324 my $old_af = $|; $| = 1; $| = $old_af;
328 $obj->{base_offset} = $bytes_read;
331 # Get our type from master index header
333 my $tag = $self->load_tag($obj->_base_offset);
336 $self->_throw_error("Corrupted file, no master index record");
339 unless ($obj->_type eq $tag->{signature}) {
341 $self->_throw_error("File type mismatch");
346 $self->calculate_sizes;
349 #XXX We have to make sure we don't mess up when autoflush isn't turned on
350 $self->_storage->set_inode;
360 return SIG_SIZE + $self->{data_size} + $size;
365 # Given offset, signature and content, create tag and write to disk
368 my ($offset, $sig, $content) = @_;
369 my $size = length( $content );
371 $self->_storage->print_at(
373 $sig, pack($self->{data_pack}, $size), $content,
376 return unless defined $offset;
380 #XXX Is this even used?
383 offset => $offset + SIG_SIZE + $self->{data_size},
391 # Given offset, load single tag and return signature, size and data
396 my $storage = $self->_storage;
398 my ($sig, $size) = unpack(
399 "A $self->{data_pack}",
400 $storage->read_at( $offset, SIG_SIZE + $self->{data_size} ),
405 size => $size, #XXX Is this even used?
407 offset => $offset + SIG_SIZE + $self->{data_size},
408 content => $storage->read_at( undef, $size ),
414 my ($tag, $transaction_id) = @_;
415 $transaction_id = $self->_storage->transaction_id
416 unless defined $transaction_id;
418 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
419 my ($loc, $trans_id, $is_deleted) = unpack(
420 "$self->{long_pack} C C",
421 substr( $tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
424 next if $loc != HEAD && $transaction_id != $trans_id;
425 return( $loc, $is_deleted, $i * $self->{key_size} );
433 # Adds one key/value pair to bucket list, given offset, MD5 digest of key,
434 # plain (undigested) key and value.
437 my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_;
439 # This verifies that only supported values will be stored.
441 my $r = Scalar::Util::reftype( $value );
444 last if $r eq 'HASH';
445 last if $r eq 'ARRAY';
448 "Storage of references of type '$r' is not supported."
452 my $storage = $self->_storage;
454 #ACID - This is a mutation. Must only find the exact transaction
455 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5, 1 );
458 if ( $storage->transaction_id == 0 ) {
459 @transactions = $storage->current_transactions;
462 # $self->_release_space( $size, $subloc );
463 #XXX This needs updating to use _release_space
466 my $size = $self->_length_needed( $value, $plain_key );
468 # Updating a known md5
470 my $keytag = $self->load_tag( $keyloc );
471 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
473 if ( $subloc && !$is_deleted && @transactions ) {
474 my $old_value = $self->read_from_loc( $subloc, $orig_key );
475 my $old_size = $self->_length_needed( $old_value, $plain_key );
477 for my $trans_id ( @transactions ) {
478 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
480 my $location2 = $storage->request_space( $old_size );
481 $storage->print_at( $keytag->{offset} + $offset2,
482 pack($self->{long_pack}, $location2 ),
483 pack( 'C C', $trans_id, 0 ),
485 $self->_write_value( $location2, $plain_key, $old_value, $orig_key );
490 $location = $self->_storage->request_space( $size );
491 #XXX This needs to be transactionally-aware in terms of which keytag->{offset} to use
492 $storage->print_at( $keytag->{offset} + $offset,
493 pack($self->{long_pack}, $location ),
494 pack( 'C C', $storage->transaction_id, 0 ),
499 my $keyloc = $storage->request_space( $self->tag_size( $self->{keyloc_size} ) );
501 # The bucket fit into list
502 if ( defined $offset ) {
503 $storage->print_at( $tag->{offset} + $offset,
504 $md5, pack( $self->{long_pack}, $keyloc ),
507 # If bucket didn't fit into list, split into a new index level
509 $self->split_index( $tag, $md5, $keyloc );
512 my $keytag = $self->write_tag(
513 $keyloc, SIG_KEYS, chr(0)x$self->{keyloc_size},
516 $location = $self->_storage->request_space( $size );
517 $storage->print_at( $keytag->{offset},
518 pack( $self->{long_pack}, $location ),
519 pack( 'C C', $storage->transaction_id, 0 ),
523 for my $trans_id ( @transactions ) {
524 $storage->print_at( $keytag->{offset} + $self->{key_size} * $offset++,
525 pack( $self->{long_pack}, 0 ),
526 pack( 'C C', $trans_id, 1 ),
531 $self->_write_value( $location, $plain_key, $value, $orig_key );
538 my ($key_loc, $location, $key, $value, $orig_key) = @_;
540 my $storage = $self->_storage;
542 my $dbm_deep_obj = _get_dbm_object( $value );
543 if ( $dbm_deep_obj && $dbm_deep_obj->_storage ne $storage ) {
544 $self->_throw_error( "Cannot cross-reference. Use export() instead" );
548 # Write signature based on content type, set content length and write
551 my $r = Scalar::Util::reftype( $value ) || '';
552 if ( $dbm_deep_obj ) {
553 $self->write_tag( $location, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) );
555 elsif ($r eq 'HASH') {
556 if ( !$dbm_deep_obj && tied %{$value} ) {
557 $self->_throw_error( "Cannot store something that is tied" );
559 $self->write_tag( $location, SIG_HASH, chr(0)x$self->{index_size} );
561 elsif ($r eq 'ARRAY') {
562 if ( !$dbm_deep_obj && tied @{$value} ) {
563 $self->_throw_error( "Cannot store something that is tied" );
565 $self->write_tag( $location, SIG_ARRAY, chr(0)x$self->{index_size} );
567 elsif (!defined($value)) {
568 $self->write_tag( $location, SIG_NULL, '' );
571 $self->write_tag( $location, SIG_DATA, $value );
575 # Plain key is stored AFTER value, as keys are typically fetched less often.
577 $storage->print_at( undef, pack($self->{data_pack}, length($key)) . $key );
579 # Internal references don't care about autobless
580 return 1 if $dbm_deep_obj;
583 # If value is blessed, preserve class name
585 if ( $storage->{autobless} ) {
586 if ( defined( my $c = Scalar::Util::blessed($value) ) ) {
587 $storage->print_at( undef, chr(1), pack($self->{data_pack}, length($c)) . $c );
590 $storage->print_at( undef, chr(0) );
595 # Tie the passed in reference so that changes to it are reflected in the
596 # datafile. The use of $location as the base_offset will act as the
597 # the linkage between parent and child.
599 # The overall assignment is a hack around the fact that just tying doesn't
600 # store the values. This may not be the wrong thing to do.
604 tie %$value, 'DBM::Deep', {
605 base_offset => $key_loc,
607 parent => $self->{obj},
608 parent_key => $orig_key,
611 bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value );
613 elsif ($r eq 'ARRAY') {
615 tie @$value, 'DBM::Deep', {
616 base_offset => $key_loc,
618 parent => $self->{obj},
619 parent_key => $orig_key,
622 bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value );
630 my ($tag, $md5, $keyloc) = @_;
632 my $storage = $self->_storage;
634 my $loc = $storage->request_space(
635 $self->tag_size( $self->{index_size} ),
638 $storage->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) );
640 my $index_tag = $self->write_tag(
642 chr(0)x$self->{index_size},
645 my $keys = $tag->{content}
646 . $md5 . pack($self->{long_pack}, $keyloc);
650 # The <= here is deliberate - we have max_buckets+1 keys to iterate
651 # through, unlike every other loop that uses max_buckets as a stop.
652 for (my $i = 0; $i <= $self->{max_buckets}; $i++) {
653 my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i );
655 die "[INTERNAL ERROR]: No key in split_index()\n" unless $key;
656 die "[INTERNAL ERROR]: No subloc in split_index()\n" unless $old_subloc;
658 my $num = ord(substr($key, $tag->{ch} + 1, 1));
661 my $subkeys = $storage->read_at( $newloc[$num], $self->{bucket_list_size} );
663 # This is looking for the first empty spot
664 my ($subloc, $offset) = $self->_find_in_buckets(
665 { content => $subkeys }, '',
669 $newloc[$num] + $offset,
670 $key, pack($self->{long_pack}, $old_subloc),
676 my $loc = $storage->request_space(
677 $self->tag_size( $self->{bucket_list_size} ),
681 $index_tag->{offset} + ($num * $self->{long_size}),
682 pack($self->{long_pack}, $loc),
685 my $blist_tag = $self->write_tag(
687 chr(0)x$self->{bucket_list_size},
690 $storage->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) );
692 $newloc[$num] = $blist_tag->{offset};
695 $self->_release_space(
696 $self->tag_size( $self->{bucket_list_size} ),
705 my ($key_loc, $subloc, $orig_key) = @_;
707 my $storage = $self->_storage;
709 my $signature = $storage->read_at( $subloc, SIG_SIZE );
712 # If value is a hash or array, return new DBM::Deep object with correct offset
714 if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) {
715 #XXX This needs to be a singleton
718 # if ( $signature eq SIG_HASH ) {
720 # tie %$new_obj, 'DBM::Deep', {
721 # base_offset => $subloc,
722 # storage => $self->_storage,
723 # parent => $self->{obj},
724 # parent_key => $orig_key,
726 # $is_autobless = tied(%$new_obj)->_storage->{autobless};
730 # tie @$new_obj, 'DBM::Deep', {
731 # base_offset => $subloc,
732 # storage => $self->_storage,
733 # parent => $self->{obj},
734 # parent_key => $orig_key,
736 # $is_autobless = tied(@$new_obj)->_storage->{autobless};
739 # if ($is_autobless) {
741 my $new_obj = DBM::Deep->new({
743 base_offset => $key_loc,
744 storage => $self->_storage,
745 parent => $self->{obj},
746 parent_key => $orig_key,
749 if ($new_obj->_storage->{autobless}) {
751 # Skip over value and plain key to see if object needs
754 $storage->increment_pointer( $self->{data_size} + $self->{index_size} );
756 my $size = $storage->read_at( undef, $self->{data_size} );
757 $size = unpack($self->{data_pack}, $size);
758 if ($size) { $storage->increment_pointer( $size ); }
760 my $bless_bit = $storage->read_at( undef, 1 );
761 if ( ord($bless_bit) ) {
764 $storage->read_at( undef, $self->{data_size} ),
768 $new_obj = bless $new_obj, $storage->read_at( undef, $size );
775 elsif ( $signature eq SIG_INTERNAL ) {
776 my $size = $storage->read_at( undef, $self->{data_size} );
777 $size = unpack($self->{data_pack}, $size);
780 my $new_loc = $storage->read_at( undef, $size );
781 $new_loc = unpack( $self->{long_pack}, $new_loc );
782 return $self->read_from_loc( $key_loc, $new_loc, $orig_key );
789 # Otherwise return actual value
791 elsif ( $signature eq SIG_DATA ) {
792 my $size = $storage->read_at( undef, $self->{data_size} );
793 $size = unpack($self->{data_pack}, $size);
795 my $value = $size ? $storage->read_at( undef, $size ) : '';
800 # Key exists, but content is null
805 sub get_bucket_value {
807 # Fetch single value given tag and MD5 digested key.
810 my ($tag, $md5, $orig_key) = @_;
812 #ACID - This is a read. Can find exact or HEAD
813 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
816 #XXX Need to use real key
817 # $self->add_bucket( $tag, $md5, $orig_key, undef, $orig_key );
820 # elsif ( !$is_deleted ) {
822 my $keytag = $self->load_tag( $keyloc );
823 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
824 if (!$subloc && !$is_deleted) {
825 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
827 if ( $subloc && !$is_deleted ) {
828 return $self->read_from_loc( $subloc, $orig_key );
837 # Delete single key/value pair given tag and MD5 digested key.
840 my ($tag, $md5, $orig_key) = @_;
842 #ACID - Although this is a mutation, we must find any transaction.
843 # This is because we need to mark something as deleted that is in the HEAD.
844 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
848 my $storage = $self->_storage;
851 if ( $storage->transaction_id == 0 ) {
852 @transactions = $storage->current_transactions;
855 if ( $storage->transaction_id == 0 ) {
856 my $keytag = $self->load_tag( $keyloc );
858 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
859 return if !$subloc || $is_deleted;
861 my $value = $self->read_from_loc( $subloc, $orig_key );
863 my $size = $self->_length_needed( $value, $orig_key );
865 for my $trans_id ( @transactions ) {
866 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
868 my $location2 = $storage->request_space( $size );
869 $storage->print_at( $keytag->{offset} + $offset2,
870 pack($self->{long_pack}, $location2 ),
871 pack( 'C C', $trans_id, 0 ),
873 $self->_write_value( $location2, $orig_key, $value, $orig_key );
877 $keytag = $self->load_tag( $keyloc );
878 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
879 $storage->print_at( $keytag->{offset} + $offset,
880 substr( $keytag->{content}, $offset + $self->{key_size} ),
881 chr(0) x $self->{key_size},
885 my $keytag = $self->load_tag( $keyloc );
887 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
889 $storage->print_at( $keytag->{offset} + $offset,
890 pack($self->{long_pack}, 0 ),
891 pack( 'C C', $storage->transaction_id, 1 ),
900 # Check existence of single key given tag and MD5 digested key.
903 my ($tag, $md5) = @_;
905 #ACID - This is a read. Can find exact or HEAD
906 my ($keyloc) = $self->_find_in_buckets( $tag, $md5 );
907 my $keytag = $self->load_tag( $keyloc );
908 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
909 if ( !$subloc && !$is_deleted ) {
910 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag, 0 );
912 return ($subloc && !$is_deleted) && 1;
917 # Locate offset for bucket list, given digested key
920 my ($offset, $md5, $args) = @_;
921 $args = {} unless $args;
924 # Locate offset for bucket list using digest index system
926 my $tag = $self->load_tag( $offset )
927 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
929 #XXX What happens when $ch >= $self->{hash_size} ??
930 for (my $ch = 0; $tag->{signature} ne SIG_BLIST; $ch++) {
931 my $num = ord substr($md5, $ch, 1);
933 my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
934 $tag = $self->index_lookup( $tag, $num );
937 return if !$args->{create};
939 my $loc = $self->_storage->request_space(
940 $self->tag_size( $self->{bucket_list_size} ),
943 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
945 $tag = $self->write_tag(
947 chr(0)x$self->{bucket_list_size},
950 $tag->{ref_loc} = $ref_loc;
957 $tag->{ref_loc} = $ref_loc;
965 # Given index tag, lookup single entry in index and return .
968 my ($tag, $index) = @_;
970 my $location = unpack(
974 $index * $self->{long_size},
979 if (!$location) { return; }
981 return $self->load_tag( $location );
986 # Scan index and recursively step into deeper levels, looking for next key.
989 my ($xxxx, $offset, $ch, $force_return_next) = @_;
991 my $tag = $self->load_tag( $offset );
993 if ($tag->{signature} ne SIG_BLIST) {
994 my $start = $xxxx->{return_next} ? 0 : ord(substr($xxxx->{prev_md5}, $ch, 1));
996 for (my $idx = $start; $idx < $self->{hash_chars_used}; $idx++) {
1001 $idx * $self->{long_size},
1007 my $result = $self->traverse_index(
1008 $xxxx, $subloc, $ch + 1, $force_return_next,
1011 if (defined $result) { return $result; }
1015 $xxxx->{return_next} = 1;
1017 # This is the bucket list
1019 my $keys = $tag->{content};
1020 if ($force_return_next) { $xxxx->{return_next} = 1; }
1023 # Iterate through buckets, looking for a key match
1025 my $transaction_id = $self->_storage->transaction_id;
1026 for (my $i = 0; $i < $self->{max_buckets}; $i++) {
1027 my ($key, $keyloc) = $self->_get_key_subloc( $keys, $i );
1029 # End of bucket list -- return to outer loop
1031 $xxxx->{return_next} = 1;
1034 # Located previous key -- return next one found
1035 elsif ($key eq $xxxx->{prev_md5}) {
1036 $xxxx->{return_next} = 1;
1039 # Seek to bucket location and skip over signature
1040 elsif ($xxxx->{return_next}) {
1041 my $storage = $self->_storage;
1043 my $keytag = $self->load_tag( $keyloc );
1044 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
1045 if ( $subloc == 0 && !$is_deleted ) {
1046 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
1048 next if $is_deleted;
1050 # Skip over value to get to plain key
1051 my $sig = $storage->read_at( $subloc, SIG_SIZE );
1053 my $size = $storage->read_at( undef, $self->{data_size} );
1054 $size = unpack($self->{data_pack}, $size);
1055 if ($size) { $storage->increment_pointer( $size ); }
1057 # Read in plain key and return as scalar
1058 $size = $storage->read_at( undef, $self->{data_size} );
1059 $size = unpack($self->{data_pack}, $size);
1062 if ($size) { $plain_key = $storage->read_at( undef, $size); }
1067 $xxxx->{return_next} = 1;
1075 sub _get_key_subloc {
1077 my ($keys, $idx) = @_;
1080 # This is 'a', not 'A'. Please read the pack() documentation for the
1081 # difference between the two and why it's important.
1082 "a$self->{hash_size} $self->{long_pack}",
1085 ($idx * $self->{bucket_size}),
1086 $self->{bucket_size},
1091 sub _find_in_buckets {
1093 my ($tag, $md5) = @_;
1096 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
1097 my ($key, $subloc) = $self->_get_key_subloc(
1098 $tag->{content}, $i,
1101 next BUCKET if $subloc && $key ne $md5;
1102 return( $subloc, $i * $self->{bucket_size} );
1108 sub _release_space {
1110 my ($size, $loc) = @_;
1114 $self->_storage->print_at( $loc,
1116 pack($self->{long_pack}, $size ),
1117 pack($self->{long_pack}, $next_loc ),
1124 die "DBM::Deep: $_[1]\n";
1127 sub _get_dbm_object {
1131 local $SIG{__DIE__};
1132 if ($item->isa( 'DBM::Deep' )) {
1137 return $obj if $obj;
1139 my $r = Scalar::Util::reftype( $item ) || '';
1140 if ( $r eq 'HASH' ) {
1142 local $SIG{__DIE__};
1143 my $obj = tied(%$item);
1144 if ($obj->isa( 'DBM::Deep' )) {
1149 return $obj if $obj;
1151 elsif ( $r eq 'ARRAY' ) {
1153 local $SIG{__DIE__};
1154 my $obj = tied(@$item);
1155 if ($obj->isa( 'DBM::Deep' )) {
1160 return $obj if $obj;
1166 sub _length_needed {
1168 my ($value, $key) = @_;
1170 my $is_dbm_deep = eval {
1171 local $SIG{'__DIE__'};
1172 $value->isa( 'DBM::Deep' );
1176 + $self->{data_size} # size for value
1177 + $self->{data_size} # size for key
1178 + length( $key ); # length of key
1180 if ( $is_dbm_deep && $value->_storage eq $self->_storage ) {
1181 # long_size is for the internal reference
1182 return $len + $self->{long_size};
1185 if ( $self->_storage->{autobless} ) {
1186 # This is for the bit saying whether or not this thing is blessed.
1190 my $r = Scalar::Util::reftype( $value ) || '';
1191 unless ( $r eq 'HASH' || $r eq 'ARRAY' ) {
1192 if ( defined $value ) {
1193 $len += length( $value );
1198 $len += $self->{index_size};
1200 # if autobless is enabled, must also take into consideration
1201 # the class name as it is stored after the key.
1202 if ( $self->_storage->{autobless} ) {
1203 my $c = Scalar::Util::blessed($value);
1204 if ( defined $c && !$is_dbm_deep ) {
1205 $len += $self->{data_size} + length($c);