1 package DBM::Deep::Engine;
8 our $VERSION = q(0.99_03);
10 use Fcntl qw( :DEFAULT :flock );
14 # * To add to bucket_size, make sure you modify the following:
17 # - add_bucket() - where the buckets are printed
19 # * Every method in here assumes that the _storage has been appropriately
20 # safeguarded. This can be anything from flock() to some sort of manual
21 # mutex. But, it's the caller's responsability to make sure that this has
25 # Setup file and tag signatures. These should never change.
27 sub SIG_FILE () { 'DPDB' }
28 sub SIG_HEADER () { 'h' }
29 sub SIG_INTERNAL () { 'i' }
30 sub SIG_HASH () { 'H' }
31 sub SIG_ARRAY () { 'A' }
32 sub SIG_NULL () { 'N' }
33 sub SIG_DATA () { 'D' }
34 sub SIG_INDEX () { 'I' }
35 sub SIG_BLIST () { 'B' }
36 sub SIG_FREE () { 'F' }
37 sub SIG_KEYS () { 'K' }
40 ################################################################################
42 # This is new code. It is a complete rewrite of the engine based on a new API
44 ################################################################################
48 my ($offset, $key, $orig_key) = @_;
50 my $dig_key = $self->apply_digest( $key );
51 my $tag = $self->find_blist( $offset, $dig_key ) or return;
52 return $self->get_bucket_value( $tag, $dig_key, $orig_key );
58 my ($trans_id, $base_offset, $key) = @_;
60 my ($_val_offset, $_is_del) = $self->_find_value_offset({
61 offset => $base_offset,
62 trans_id => $trans_id,
65 die "Attempt to use a deleted value" if $_is_del;
66 die "Internal error!" if !$_val_offset;
68 my ($key_offset) = $self->_find_key_offset({
69 offset => $_val_offset,
70 key_md5 => $self->_apply_digest( $key ),
73 return if !$key_offset;
75 my ($val_offset, $is_del) = $self->_find_value_offset({
76 offset => $key_offset,
77 trans_id => $trans_id,
81 die "Internal error!" if !$val_offset;
83 return $self->_read_value({
84 offset => $val_offset,
91 my ($offset, $key) = @_;
93 my $dig_key = $self->apply_digest( $key );
94 # exists() returns the empty string, not undef
95 my $tag = $self->find_blist( $offset, $dig_key ) or return '';
96 return $self->bucket_exists( $tag, $dig_key, $key );
102 my ($trans_id, $base_offset, $key) = @_;
104 my ($_val_offset, $_is_del) = $self->_find_value_offset({
105 offset => $base_offset,
106 trans_id => $trans_id,
109 die "Attempt to use a deleted value" if $_is_del;
110 die "Internal error!" if !$_val_offset;
112 my ($key_offset) = $self->_find_key_offset({
113 offset => $_val_offset,
114 key_md5 => $self->_apply_digest( $key ),
117 return if !$key_offset;
119 my ($val_offset, $is_del) = $self->_find_value_offset({
120 offset => $key_offset,
121 trans_id => $trans_id,
127 die "Internal error!" if !$_val_offset;
136 # If the previous key was not specifed, start at the top and
137 # return the first one found.
141 prev_md5 => $self->apply_digest($_[1]),
147 prev_md5 => chr(0) x $self->{hash_size},
152 return $self->traverse_index( $temp, $offset, 0 );
157 my ($offset, $key, $orig_key) = @_;
159 my $dig_key = $self->apply_digest( $key );
160 my $tag = $self->find_blist( $offset, $dig_key ) or return;
161 my $value = $self->get_bucket_value( $tag, $dig_key, $orig_key );
162 $self->delete_bucket( $tag, $dig_key, $orig_key );
169 my ($trans_id, $base_offset, $key) = @_;
171 my ($_val_offset, $_is_del) = $self->_find_value_offset({
172 offset => $base_offset,
173 trans_id => $trans_id,
176 die "Attempt to use a deleted value" if $_is_del;
177 die "Internal error!" if !$_val_offset;
179 my ($key_offset) = $self->_find_key_offset({
180 offset => $_val_offset,
181 key_md5 => $self->_apply_digest( $key ),
184 return if !$key_offset;
187 $self->_mark_as_deleted({
188 offset => $key_offset,
189 trans_id => $trans_id,
193 my $value = $self->read_value( $trans_id, $base_offset, $key );
194 if ( @transactions ) {
195 foreach my $other_trans_id ( @transactions ) {
197 # next if the $trans_id has an entry in the keyloc
198 # store $value for $other_trans_id
202 $self->_remove_key_offset({
203 offset => $_val_offset,
204 key_md5 => $self->_apply_digest( $key ),
213 my ($offset, $key, $value, $orig_key) = @_;
215 my $dig_key = $self->apply_digest( $key );
216 my $tag = $self->find_blist( $offset, $dig_key, { create => 1 } );
217 return $self->add_bucket( $tag, $dig_key, $key, $value, undef, $orig_key );
223 my ($trans_id, $base_offset, $key) = @_;
225 my ($_val_offset, $_is_del) = $self->_find_value_offset({
226 offset => $base_offset,
227 trans_id => $trans_id,
230 die "Attempt to use a deleted value" if $_is_del;
231 die "Internal error!" if !$_val_offset;
233 my ($key_offset, $is_new) = $self->_find_key_offset({
234 offset => $_val_offset,
235 key_md5 => $self->_apply_digest( $key ),
238 die "Cannot find/create new key offset!" if !$key_offset;
244 ################################################################################
246 # Below here is the old code. It will be folded into the code above as it can.
248 ################################################################################
260 digest => \&Digest::MD5::md5,
261 hash_size => 16, # In bytes
264 # Number of buckets per blist before another level of indexing is
265 # done. Increase this value for slightly greater speed, but larger database
266 # files. DO NOT decrease this value below 16, due to risk of recursive
275 if ( defined $args->{pack_size} ) {
276 if ( lc $args->{pack_size} eq 'small' ) {
277 $args->{long_size} = 2;
278 $args->{long_pack} = 'n';
280 elsif ( lc $args->{pack_size} eq 'medium' ) {
281 $args->{long_size} = 4;
282 $args->{long_pack} = 'N';
284 elsif ( lc $args->{pack_size} eq 'large' ) {
285 $args->{long_size} = 8;
286 $args->{long_pack} = 'Q';
289 die "Unknown pack_size value: '$args->{pack_size}'\n";
293 # Grab the parameters we want to use
294 foreach my $param ( keys %$self ) {
295 next unless exists $args->{$param};
296 $self->{$param} = $args->{$param};
298 Scalar::Util::weaken( $self->{obj} ) if $self->{obj};
300 if ( $self->{max_buckets} < 16 ) {
301 warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n";
302 $self->{max_buckets} = 16;
308 sub _storage { return $_[0]{storage} }
312 return $self->{digest}->(@_);
315 sub calculate_sizes {
318 # The 2**8 here indicates the number of different characters in the
319 # current hashing algorithm
320 #XXX Does this need to be updated with different hashing algorithms?
321 $self->{hash_chars_used} = (2**8);
322 $self->{index_size} = $self->{hash_chars_used} * $self->{long_size};
324 $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2;
325 $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size};
327 $self->{key_size} = $self->{long_size} * 2;
328 $self->{keyloc_size} = $self->{max_buckets} * $self->{key_size};
333 sub write_file_header {
336 my $loc = $self->_storage->request_space( length( SIG_FILE ) + 33 );
338 $self->_storage->print_at( $loc,
341 pack('N', 1), # header version
342 pack('N', 24), # header size
343 pack('N4', 0, 0, 0, 0), # currently running transaction IDs
344 pack('n', $self->{long_size}),
345 pack('A', $self->{long_pack}),
346 pack('n', $self->{data_size}),
347 pack('A', $self->{data_pack}),
348 pack('n', $self->{max_buckets}),
351 $self->_storage->set_transaction_offset( 13 );
356 sub read_file_header {
359 my $buffer = $self->_storage->read_at( 0, length(SIG_FILE) + 9 );
360 return unless length($buffer);
362 my ($file_signature, $sig_header, $header_version, $size) = unpack(
366 unless ( $file_signature eq SIG_FILE ) {
367 $self->_storage->close;
368 $self->_throw_error( "Signature not found -- file is not a Deep DB" );
371 unless ( $sig_header eq SIG_HEADER ) {
372 $self->_storage->close;
373 $self->_throw_error( "Old file version found." );
376 my $buffer2 = $self->_storage->read_at( undef, $size );
377 my ($a1, $a2, $a3, $a4, @values) = unpack( 'N4 n A n A n', $buffer2 );
379 $self->_storage->set_transaction_offset( 13 );
381 if ( @values < 5 || grep { !defined } @values ) {
382 $self->_storage->close;
383 $self->_throw_error("Corrupted file - bad header");
386 #XXX Add warnings if values weren't set right
387 @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values;
389 return length($buffer) + length($buffer2);
396 # Need to remove use of $fh here
397 my $fh = $self->_storage->{fh};
400 #XXX The duplication of calculate_sizes needs to go away
401 unless ( $obj->{base_offset} ) {
402 my $bytes_read = $self->read_file_header;
404 $self->calculate_sizes;
407 # File is empty -- write header and master index
410 $self->_storage->audit( "# Database created on" );
412 $self->write_file_header;
414 $obj->{base_offset} = $self->_storage->request_space(
415 $self->tag_size( $self->{index_size} ),
419 $obj->_base_offset, $obj->_type,
420 chr(0)x$self->{index_size},
423 # Flush the filehandle
424 my $old_fh = select $fh;
425 my $old_af = $|; $| = 1; $| = $old_af;
429 $obj->{base_offset} = $bytes_read;
432 # Get our type from master index header
434 my $tag = $self->load_tag($obj->_base_offset);
437 $self->_throw_error("Corrupted file, no master index record");
440 unless ($obj->_type eq $tag->{signature}) {
442 $self->_throw_error("File type mismatch");
447 $self->calculate_sizes;
450 #XXX We have to make sure we don't mess up when autoflush isn't turned on
451 $self->_storage->set_inode;
461 return SIG_SIZE + $self->{data_size} + $size;
466 # Given offset, signature and content, create tag and write to disk
469 my ($offset, $sig, $content) = @_;
470 my $size = length( $content );
472 $self->_storage->print_at(
474 $sig, pack($self->{data_pack}, $size), $content,
477 return unless defined $offset;
481 #XXX Is this even used?
483 offset => $offset + SIG_SIZE + $self->{data_size},
490 # Given offset, load single tag and return signature, size and data
495 my $storage = $self->_storage;
497 my ($sig, $size) = unpack(
498 "A $self->{data_pack}",
499 $storage->read_at( $offset, SIG_SIZE + $self->{data_size} ),
504 size => $size, #XXX Is this even used?
505 offset => $offset + SIG_SIZE + $self->{data_size},
506 content => $storage->read_at( undef, $size ),
512 my ($tag, $transaction_id) = @_;
513 $transaction_id = $self->_storage->transaction_id
514 unless defined $transaction_id;
516 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
517 my ($loc, $trans_id, $is_deleted) = unpack(
518 "$self->{long_pack} C C",
519 substr( $tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
523 return ( $loc, $is_deleted, $i * $self->{key_size} );
526 next if $transaction_id != $trans_id;
528 return ( $loc, $is_deleted, $i * $self->{key_size} );
536 # Adds one key/value pair to bucket list, given offset, MD5 digest of key,
537 # plain (undigested) key and value.
540 my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_;
542 # This verifies that only supported values will be stored.
544 my $r = Scalar::Util::reftype( $value );
547 last if $r eq 'HASH';
548 last if $r eq 'ARRAY';
551 "Storage of references of type '$r' is not supported."
555 my $storage = $self->_storage;
557 #ACID - This is a mutation. Must only find the exact transaction
558 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5, 1 );
561 if ( $storage->transaction_id == 0 ) {
562 @transactions = $storage->current_transactions;
565 # $self->_release_space( $size, $subloc );
566 #XXX This needs updating to use _release_space
569 my $size = $self->_length_needed( $value, $plain_key );
571 # Updating a known md5
573 my $keytag = $self->load_tag( $keyloc );
574 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
576 if ( $subloc && !$is_deleted && @transactions ) {
577 my $old_value = $self->read_from_loc( $subloc, $orig_key );
578 my $old_size = $self->_length_needed( $old_value, $plain_key );
580 for my $trans_id ( @transactions ) {
581 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
583 my $location2 = $storage->request_space( $old_size );
584 $storage->print_at( $keytag->{offset} + $offset2,
585 pack($self->{long_pack}, $location2 ),
586 pack( 'C C', $trans_id, 0 ),
588 $self->_write_value( $location2, $plain_key, $old_value, $orig_key );
593 $location = $self->_storage->request_space( $size );
594 #XXX This needs to be transactionally-aware in terms of which keytag->{offset} to use
595 $storage->print_at( $keytag->{offset} + $offset,
596 pack($self->{long_pack}, $location ),
597 pack( 'C C', $storage->transaction_id, 0 ),
602 my $keyloc = $storage->request_space( $self->tag_size( $self->{keyloc_size} ) );
604 # The bucket fit into list
605 if ( defined $offset ) {
606 $storage->print_at( $tag->{offset} + $offset,
607 $md5, pack( $self->{long_pack}, $keyloc ),
610 # If bucket didn't fit into list, split into a new index level
612 $self->split_index( $tag, $md5, $keyloc );
615 my $keytag = $self->write_tag(
616 $keyloc, SIG_KEYS, chr(0)x$self->{keyloc_size},
619 $location = $self->_storage->request_space( $size );
620 $storage->print_at( $keytag->{offset},
621 pack( $self->{long_pack}, $location ),
622 pack( 'C C', $storage->transaction_id, 0 ),
626 for my $trans_id ( @transactions ) {
627 $storage->print_at( $keytag->{offset} + $self->{key_size} * $offset++,
628 pack( $self->{long_pack}, 0 ),
629 pack( 'C C', $trans_id, 1 ),
634 $self->_write_value( $location, $plain_key, $value, $orig_key );
641 my ($location, $key, $value, $orig_key) = @_;
643 my $storage = $self->_storage;
645 my $dbm_deep_obj = _get_dbm_object( $value );
646 if ( $dbm_deep_obj && $dbm_deep_obj->_storage ne $storage ) {
647 $self->_throw_error( "Cannot cross-reference. Use export() instead" );
651 # Write signature based on content type, set content length and write
654 my $r = Scalar::Util::reftype( $value ) || '';
655 if ( $dbm_deep_obj ) {
656 $self->write_tag( $location, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) );
658 elsif ($r eq 'HASH') {
659 if ( !$dbm_deep_obj && tied %{$value} ) {
660 $self->_throw_error( "Cannot store something that is tied" );
662 $self->write_tag( $location, SIG_HASH, chr(0)x$self->{index_size} );
664 elsif ($r eq 'ARRAY') {
665 if ( !$dbm_deep_obj && tied @{$value} ) {
666 $self->_throw_error( "Cannot store something that is tied" );
668 $self->write_tag( $location, SIG_ARRAY, chr(0)x$self->{index_size} );
670 elsif (!defined($value)) {
671 $self->write_tag( $location, SIG_NULL, '' );
674 $self->write_tag( $location, SIG_DATA, $value );
678 # Plain key is stored AFTER value, as keys are typically fetched less often.
680 $storage->print_at( undef, pack($self->{data_pack}, length($key)) . $key );
682 # Internal references don't care about autobless
683 return 1 if $dbm_deep_obj;
686 # If value is blessed, preserve class name
688 if ( $storage->{autobless} ) {
689 if ( defined( my $c = Scalar::Util::blessed($value) ) ) {
690 $storage->print_at( undef, chr(1), pack($self->{data_pack}, length($c)) . $c );
693 $storage->print_at( undef, chr(0) );
698 # Tie the passed in reference so that changes to it are reflected in the
699 # datafile. The use of $location as the base_offset will act as the
700 # the linkage between parent and child.
702 # The overall assignment is a hack around the fact that just tying doesn't
703 # store the values. This may not be the wrong thing to do.
707 tie %$value, 'DBM::Deep', {
708 base_offset => $location,
710 parent => $self->{obj},
711 parent_key => $orig_key,
714 bless $value, 'DBM::Deep::Hash' unless Scalar::Util::blessed( $value );
716 elsif ($r eq 'ARRAY') {
718 tie @$value, 'DBM::Deep', {
719 base_offset => $location,
721 parent => $self->{obj},
722 parent_key => $orig_key,
725 bless $value, 'DBM::Deep::Array' unless Scalar::Util::blessed( $value );
733 my ($tag, $md5, $keyloc) = @_;
735 my $storage = $self->_storage;
737 my $loc = $storage->request_space(
738 $self->tag_size( $self->{index_size} ),
741 $storage->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) );
743 my $index_tag = $self->write_tag(
745 chr(0)x$self->{index_size},
748 my $keys = $tag->{content}
749 . $md5 . pack($self->{long_pack}, $keyloc);
753 # The <= here is deliberate - we have max_buckets+1 keys to iterate
754 # through, unlike every other loop that uses max_buckets as a stop.
755 for (my $i = 0; $i <= $self->{max_buckets}; $i++) {
756 my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i );
758 die "[INTERNAL ERROR]: No key in split_index()\n" unless $key;
759 die "[INTERNAL ERROR]: No subloc in split_index()\n" unless $old_subloc;
761 my $num = ord(substr($key, $tag->{ch} + 1, 1));
764 my $subkeys = $storage->read_at( $newloc[$num], $self->{bucket_list_size} );
766 # This is looking for the first empty spot
767 my ($subloc, $offset) = $self->_find_in_buckets(
768 { content => $subkeys }, '',
772 $newloc[$num] + $offset,
773 $key, pack($self->{long_pack}, $old_subloc),
779 my $loc = $storage->request_space(
780 $self->tag_size( $self->{bucket_list_size} ),
784 $index_tag->{offset} + ($num * $self->{long_size}),
785 pack($self->{long_pack}, $loc),
788 my $blist_tag = $self->write_tag(
790 chr(0)x$self->{bucket_list_size},
793 $storage->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) );
795 $newloc[$num] = $blist_tag->{offset};
798 $self->_release_space(
799 $self->tag_size( $self->{bucket_list_size} ),
800 $tag->{offset} - SIG_SIZE - $self->{data_size},
808 my ($subloc, $orig_key) = @_;
810 my $storage = $self->_storage;
812 my $signature = $storage->read_at( $subloc, SIG_SIZE );
815 # If value is a hash or array, return new DBM::Deep object with correct offset
817 if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) {
818 #XXX This needs to be a singleton
821 # if ( $signature eq SIG_HASH ) {
823 # tie %$new_obj, 'DBM::Deep', {
824 # base_offset => $subloc,
825 # storage => $self->_storage,
826 # parent => $self->{obj},
827 # parent_key => $orig_key,
829 # $is_autobless = tied(%$new_obj)->_storage->{autobless};
833 # tie @$new_obj, 'DBM::Deep', {
834 # base_offset => $subloc,
835 # storage => $self->_storage,
836 # parent => $self->{obj},
837 # parent_key => $orig_key,
839 # $is_autobless = tied(@$new_obj)->_storage->{autobless};
842 # if ($is_autobless) {
844 my $new_obj = DBM::Deep->new({
846 base_offset => $subloc,
847 storage => $self->_storage,
848 parent => $self->{obj},
849 parent_key => $orig_key,
852 if ($new_obj->_storage->{autobless}) {
854 # Skip over value and plain key to see if object needs
857 $storage->increment_pointer( $self->{data_size} + $self->{index_size} );
859 my $size = $storage->read_at( undef, $self->{data_size} );
860 $size = unpack($self->{data_pack}, $size);
861 if ($size) { $storage->increment_pointer( $size ); }
863 my $bless_bit = $storage->read_at( undef, 1 );
864 if ( ord($bless_bit) ) {
867 $storage->read_at( undef, $self->{data_size} ),
871 $new_obj = bless $new_obj, $storage->read_at( undef, $size );
878 elsif ( $signature eq SIG_INTERNAL ) {
879 my $size = $storage->read_at( undef, $self->{data_size} );
880 $size = unpack($self->{data_pack}, $size);
883 my $new_loc = $storage->read_at( undef, $size );
884 $new_loc = unpack( $self->{long_pack}, $new_loc );
885 return $self->read_from_loc( $new_loc, $orig_key );
892 # Otherwise return actual value
894 elsif ( $signature eq SIG_DATA ) {
895 my $size = $storage->read_at( undef, $self->{data_size} );
896 $size = unpack($self->{data_pack}, $size);
898 my $value = $size ? $storage->read_at( undef, $size ) : '';
903 # Key exists, but content is null
908 sub get_bucket_value {
910 # Fetch single value given tag and MD5 digested key.
913 my ($tag, $md5, $orig_key) = @_;
915 #ACID - This is a read. Can find exact or HEAD
916 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
919 #XXX Need to use real key
920 # $self->add_bucket( $tag, $md5, $orig_key, undef, $orig_key );
923 # elsif ( !$is_deleted ) {
925 my $keytag = $self->load_tag( $keyloc );
926 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
927 if (!$subloc && !$is_deleted) {
928 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
930 if ( $subloc && !$is_deleted ) {
931 return $self->read_from_loc( $subloc, $orig_key );
940 # Delete single key/value pair given tag and MD5 digested key.
943 my ($tag, $md5, $orig_key) = @_;
945 #ACID - Although this is a mutation, we must find any transaction.
946 # This is because we need to mark something as deleted that is in the HEAD.
947 my ($keyloc, $offset) = $self->_find_in_buckets( $tag, $md5 );
951 my $storage = $self->_storage;
954 if ( $storage->transaction_id == 0 ) {
955 @transactions = $storage->current_transactions;
958 if ( $storage->transaction_id == 0 ) {
959 my $keytag = $self->load_tag( $keyloc );
961 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
962 return if !$subloc || $is_deleted;
964 my $value = $self->read_from_loc( $subloc, $orig_key );
966 my $size = $self->_length_needed( $value, $orig_key );
968 for my $trans_id ( @transactions ) {
969 my ($loc, $is_deleted, $offset2) = $self->find_keyloc( $keytag, $trans_id );
971 my $location2 = $storage->request_space( $size );
972 $storage->print_at( $keytag->{offset} + $offset2,
973 pack($self->{long_pack}, $location2 ),
974 pack( 'C C', $trans_id, 0 ),
976 $self->_write_value( $location2, $orig_key, $value, $orig_key );
980 $keytag = $self->load_tag( $keyloc );
981 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
982 $storage->print_at( $keytag->{offset} + $offset,
983 substr( $keytag->{content}, $offset + $self->{key_size} ),
984 chr(0) x $self->{key_size},
988 my $keytag = $self->load_tag( $keyloc );
990 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
992 $storage->print_at( $keytag->{offset} + $offset,
993 pack($self->{long_pack}, 0 ),
994 pack( 'C C', $storage->transaction_id, 1 ),
1003 # Check existence of single key given tag and MD5 digested key.
1006 my ($tag, $md5) = @_;
1008 #ACID - This is a read. Can find exact or HEAD
1009 my ($keyloc) = $self->_find_in_buckets( $tag, $md5 );
1010 my $keytag = $self->load_tag( $keyloc );
1011 my ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag );
1012 if ( !$subloc && !$is_deleted ) {
1013 ($subloc, $is_deleted, $offset) = $self->find_keyloc( $keytag, 0 );
1015 return ($subloc && !$is_deleted) && 1;
1020 # Locate offset for bucket list, given digested key
1023 my ($offset, $md5, $args) = @_;
1024 $args = {} unless $args;
1027 # Locate offset for bucket list using digest index system
1029 my $tag = $self->load_tag( $offset )
1030 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
1033 while ($tag->{signature} ne SIG_BLIST) {
1034 my $num = ord substr($md5, $ch, 1);
1036 my $ref_loc = $tag->{offset} + ($num * $self->{long_size});
1037 $tag = $self->index_lookup( $tag, $num );
1040 return if !$args->{create};
1042 my $loc = $self->_storage->request_space(
1043 $self->tag_size( $self->{bucket_list_size} ),
1046 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
1048 $tag = $self->write_tag(
1050 chr(0)x$self->{bucket_list_size},
1053 $tag->{ref_loc} = $ref_loc;
1060 $tag->{ref_loc} = $ref_loc;
1068 # Given index tag, lookup single entry in index and return .
1071 my ($tag, $index) = @_;
1073 my $location = unpack(
1077 $index * $self->{long_size},
1082 if (!$location) { return; }
1084 return $self->load_tag( $location );
1087 sub traverse_index {
1089 # Scan index and recursively step into deeper levels, looking for next key.
1092 my ($xxxx, $offset, $ch, $force_return_next) = @_;
1094 my $tag = $self->load_tag( $offset );
1096 if ($tag->{signature} ne SIG_BLIST) {
1097 my $start = $xxxx->{return_next} ? 0 : ord(substr($xxxx->{prev_md5}, $ch, 1));
1099 for (my $idx = $start; $idx < $self->{hash_chars_used}; $idx++) {
1100 my $subloc = unpack(
1104 $idx * $self->{long_size},
1110 my $result = $self->traverse_index(
1111 $xxxx, $subloc, $ch + 1, $force_return_next,
1114 if (defined $result) { return $result; }
1118 $xxxx->{return_next} = 1;
1120 # This is the bucket list
1122 my $keys = $tag->{content};
1123 if ($force_return_next) { $xxxx->{return_next} = 1; }
1126 # Iterate through buckets, looking for a key match
1128 my $transaction_id = $self->_storage->transaction_id;
1129 for (my $i = 0; $i < $self->{max_buckets}; $i++) {
1130 my ($key, $keyloc) = $self->_get_key_subloc( $keys, $i );
1132 # End of bucket list -- return to outer loop
1134 $xxxx->{return_next} = 1;
1137 # Located previous key -- return next one found
1138 elsif ($key eq $xxxx->{prev_md5}) {
1139 $xxxx->{return_next} = 1;
1142 # Seek to bucket location and skip over signature
1143 elsif ($xxxx->{return_next}) {
1144 my $storage = $self->_storage;
1146 my $keytag = $self->load_tag( $keyloc );
1147 my ($subloc, $is_deleted) = $self->find_keyloc( $keytag );
1148 if ( $subloc == 0 && !$is_deleted ) {
1149 ($subloc, $is_deleted) = $self->find_keyloc( $keytag, 0 );
1151 next if $is_deleted;
1153 # Skip over value to get to plain key
1154 my $sig = $storage->read_at( $subloc, SIG_SIZE );
1156 my $size = $storage->read_at( undef, $self->{data_size} );
1157 $size = unpack($self->{data_pack}, $size);
1158 if ($size) { $storage->increment_pointer( $size ); }
1160 # Read in plain key and return as scalar
1161 $size = $storage->read_at( undef, $self->{data_size} );
1162 $size = unpack($self->{data_pack}, $size);
1165 if ($size) { $plain_key = $storage->read_at( undef, $size); }
1170 $xxxx->{return_next} = 1;
1178 sub _get_key_subloc {
1180 my ($keys, $idx) = @_;
1183 # This is 'a', not 'A'. Please read the pack() documentation for the
1184 # difference between the two and why it's important.
1185 "a$self->{hash_size} $self->{long_pack}",
1188 ($idx * $self->{bucket_size}),
1189 $self->{bucket_size},
1194 sub _find_in_buckets {
1196 my ($tag, $md5) = @_;
1199 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
1200 my ($key, $subloc) = $self->_get_key_subloc(
1201 $tag->{content}, $i,
1204 my @rv = ($subloc, $i * $self->{bucket_size});
1206 unless ( $subloc ) {
1210 next BUCKET if $key ne $md5;
1218 sub _release_space {
1220 my ($size, $loc) = @_;
1224 $self->_storage->print_at( $loc,
1226 pack($self->{long_pack}, $size ),
1227 pack($self->{long_pack}, $next_loc ),
1234 die "DBM::Deep: $_[1]\n";
1237 sub _get_dbm_object {
1241 local $SIG{__DIE__};
1242 if ($item->isa( 'DBM::Deep' )) {
1247 return $obj if $obj;
1249 my $r = Scalar::Util::reftype( $item ) || '';
1250 if ( $r eq 'HASH' ) {
1252 local $SIG{__DIE__};
1253 my $obj = tied(%$item);
1254 if ($obj->isa( 'DBM::Deep' )) {
1259 return $obj if $obj;
1261 elsif ( $r eq 'ARRAY' ) {
1263 local $SIG{__DIE__};
1264 my $obj = tied(@$item);
1265 if ($obj->isa( 'DBM::Deep' )) {
1270 return $obj if $obj;
1276 sub _length_needed {
1278 my ($value, $key) = @_;
1280 my $is_dbm_deep = eval {
1281 local $SIG{'__DIE__'};
1282 $value->isa( 'DBM::Deep' );
1286 + $self->{data_size} # size for value
1287 + $self->{data_size} # size for key
1288 + length( $key ); # length of key
1290 if ( $is_dbm_deep && $value->_storage eq $self->_storage ) {
1291 # long_size is for the internal reference
1292 return $len + $self->{long_size};
1295 if ( $self->_storage->{autobless} ) {
1296 # This is for the bit saying whether or not this thing is blessed.
1300 my $r = Scalar::Util::reftype( $value ) || '';
1301 unless ( $r eq 'HASH' || $r eq 'ARRAY' ) {
1302 if ( defined $value ) {
1303 $len += length( $value );
1308 $len += $self->{index_size};
1310 # if autobless is enabled, must also take into consideration
1311 # the class name as it is stored after the key.
1312 if ( $self->_storage->{autobless} ) {
1313 my $c = Scalar::Util::blessed($value);
1314 if ( defined $c && !$is_dbm_deep ) {
1315 $len += $self->{data_size} + length($c);