1 package DBM::Deep::Engine2;
3 use base 'DBM::Deep::Engine';
10 our $VERSION = q(0.99_03);
12 use Fcntl qw( :DEFAULT :flock );
16 # * Every method in here assumes that the _storage has been appropriately
17 # safeguarded. This can be anything from flock() to some sort of manual
18 # mutex. But, it's the caller's responsability to make sure that this has
21 # Setup file and tag signatures. These should never change.
22 sub SIG_FILE () { 'DPDB' }
23 sub SIG_HEADER () { 'h' }
24 sub SIG_INTERNAL () { 'i' }
25 sub SIG_HASH () { 'H' }
26 sub SIG_ARRAY () { 'A' }
27 sub SIG_NULL () { 'N' }
28 sub SIG_DATA () { 'D' }
29 sub SIG_INDEX () { 'I' }
30 sub SIG_BLIST () { 'B' }
31 sub SIG_FREE () { 'F' }
32 sub SIG_KEYS () { 'K' }
35 # This is the transaction ID for the HEAD
40 my ($trans_id, $base_offset, $key) = @_;
42 my ($_val_offset, $_is_del) = $self->_find_value_offset({
43 offset => $base_offset,
44 trans_id => $trans_id,
47 die "Attempt to use a deleted value" if $_is_del;
48 die "Internal error!" if !$_val_offset;
50 my ($key_offset) = $self->_find_key_offset({
51 offset => $_val_offset,
52 key_md5 => $self->_apply_digest( $key ),
54 return if !$key_offset;
56 my ($val_offset, $is_del) = $self->_find_value_offset({
57 offset => $key_offset,
58 trans_id => $trans_id,
62 die "Internal error!" if !$val_offset;
64 return $self->_read_value({
65 offset => $val_offset,
71 my ($trans_id, $base_offset, $key) = @_;
73 my ($_val_offset, $_is_del) = $self->_find_value_offset({
74 offset => $base_offset,
75 trans_id => $trans_id,
78 die "Attempt to use a deleted value" if $_is_del;
79 die "Internal error!" if !$_val_offset;
81 my ($key_offset) = $self->_find_key_offset({
82 offset => $_val_offset,
83 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;
103 # If the previous key was not specifed, start at the top and
104 # return the first one found.
108 prev_md5 => $self->apply_digest($_[1]),
114 prev_md5 => chr(0) x $self->{hash_size},
119 return $self->traverse_index( $temp, $offset, 0 );
124 my ($trans_id, $base_offset, $key) = @_;
126 my ($_val_offset, $_is_del) = $self->_find_value_offset({
127 offset => $base_offset,
128 trans_id => $trans_id,
131 die "Attempt to use a deleted value" if $_is_del;
132 die "Internal error!" if !$_val_offset;
134 my ($key_offset, $bucket_tag) = $self->_find_key_offset({
135 offset => $_val_offset,
136 key_md5 => $self->_apply_digest( $key ),
138 return if !$key_offset;
140 my $key_tag = $self->load_tag( $key_offset );
143 $self->_mark_as_deleted({
145 trans_id => $trans_id,
149 my $value = $self->read_value( $trans_id, $base_offset, $key );
150 if ( my @transactions = $self->_storage->current_transactions ) {
151 foreach my $other_trans_id ( @transactions ) {
152 next if $self->_has_keyloc_entry({
154 trans_id => $other_trans_id,
156 $self->write_value( $other_trans_id, $base_offset, $key, $value );
160 $self->_remove_key_offset({
161 offset => $_val_offset,
162 key_md5 => $self->_apply_digest( $key ),
172 my ($trans_id, $base_offset, $key, $value) = @_;
174 # This verifies that only supported values will be stored.
176 my $r = Scalar::Util::reftype( $value );
179 last if $r eq 'HASH';
180 last if $r eq 'ARRAY';
183 "Storage of references of type '$r' is not supported."
187 my ($_val_offset, $_is_del) = $self->_find_value_offset({
188 offset => $base_offset,
189 trans_id => $trans_id,
192 die "Attempt to use a deleted value" if $_is_del;
193 die "Internal error!" if !$_val_offset;
195 my ($key_offset, $bucket_tag) = $self->_find_key_offset({
196 offset => $_val_offset,
197 key_md5 => $self->_apply_digest( $key ),
200 die "Cannot find/create new key offset!" if !$key_offset;
202 my $key_tag = $self->load_tag( $key_offset );
205 if ( $bucket_tag->{is_new} ) {
206 # Must mark the HEAD as deleted because it doesn't exist
207 $self->_mark_as_deleted({
214 # If the HEAD isn't new, then we must take other transactions
215 # into account. If it is, then there can be no other transactions.
216 if ( !$bucket_tag->{is_new} ) {
217 my $old_value = $self->read_value( $trans_id, $base_offset, $key );
218 if ( my @transactions = $self->_storage->current_transactions ) {
219 foreach my $other_trans_id ( @transactions ) {
220 next if $self->_has_keyloc_entry({
222 trans_id => $other_trans_id,
224 $self->write_value( $other_trans_id, $base_offset, $key, $old_value );
230 my $value_loc = $self->_storage->request_space(
231 $self->_length_needed( $value, $key ),
234 $self->_add_key_offset({
236 trans_id => $trans_id,
240 $self->_write_value( $value_loc, $key, $value, $key );
245 sub _find_value_offset {
249 use Data::Dumper;warn Dumper $args;
251 my $key_tag = $self->load_tag( $args->{offset} );
254 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
255 my ($loc, $trans_id, $is_deleted) = unpack(
256 "$self->{long_pack} C C",
257 substr( $key_tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
260 if ( $trans_id == HEAD ) {
261 @head = ($loc, $is_deleted);
264 next if $loc && $args->{trans_id} != $trans_id;
265 return( $loc, $is_deleted );
268 return @head if $args->{allow_head};
272 #XXX Need to keep track of $bucket_tag->(ref_loc} and $bucket_tag->{ch}
273 sub _find_key_offset {
277 my $bucket_tag = $self->load_tag( $args->{offset} )
278 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
280 #XXX What happens when $ch >= $self->{hash_size} ??
281 for (my $ch = 0; $bucket_tag->{signature} ne SIG_BLIST; $ch++) {
282 my $num = ord substr($args->{key_md5}, $ch, 1);
284 my $ref_loc = $bucket_tag->{offset} + ($num * $self->{long_size});
285 $bucket_tag = $self->index_lookup( $bucket_tag, $num );
288 return if !$args->{create};
290 my $loc = $self->_storage->request_space(
291 $self->tag_size( $self->{bucket_list_size} ),
294 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
296 $bucket_tag = $self->write_tag(
298 chr(0)x$self->{bucket_list_size},
301 $bucket_tag->{ref_loc} = $ref_loc;
302 $bucket_tag->{ch} = $ch;
303 $bucket_tag->{is_new} = 1;
308 $bucket_tag->{ch} = $ch;
309 $bucket_tag->{ref_loc} = $ref_loc;
312 # Need to create a new keytag, too
313 if ( $bucket_tag->{is_new} ) {
314 my $keytag_loc = $self->_storage->request_space(
315 $self->tag_size( $self->{keyloc_size} ),
318 substr( $bucket_tag->{content}, 0, $self->{key_size} ) =
319 $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc );
321 $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} );
324 $keytag_loc, SIG_KEYS,
325 chr(0)x$self->{keyloc_size},
328 return( $keytag_loc, $bucket_tag );
331 my ($key, $subloc, $index);
333 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
334 ($key, $subloc) = $self->_get_key_subloc(
335 $bucket_tag->{content}, $i,
338 next BUCKET if $subloc && $key ne $args->{key_md5};
340 # Keep track of where we are, in case we need to create a new
346 # Either we have a subloc to return or we don't want to create a new
347 # entry. Either way, we need to return now.
348 return ($subloc, $bucket_tag) if $subloc || !$args->{create};
350 my $keytag_loc = $self->_storage->request_space(
351 $self->tag_size( $self->{keyloc_size} ),
354 # There's space left in this bucket
355 if ( defined $index ) {
356 substr( $bucket_tag->{content}, $index * $self->{key_size}, $self->{key_size} ) =
357 $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc );
359 $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} );
361 # We need to split the index
363 $self->split_index( $bucket_tag, $args->{key_md5}, $keytag_loc );
367 $keytag_loc, SIG_KEYS,
368 chr(0)x$self->{keyloc_size},
371 return( $keytag_loc, $bucket_tag );
381 return $self->read_from_loc( $args->{offset} );
384 sub _mark_as_deleted {
389 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
390 my ($loc, $trans_id, $is_deleted) = unpack(
391 "$self->{long_pack} C C",
392 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
396 if ( $trans_id == $args->{trans_id} ) {
397 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack(
398 "$self->{long_pack} C C",
405 $self->_storage->print_at(
406 $args->{tag}{offset}, $args->{tag}{content},
413 sub _has_keyloc_entry {
417 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
418 my ($loc, $trans_id, $is_deleted) = unpack(
419 "$self->{long_pack} C C",
420 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
423 return 1 if $trans_id == $args->{trans_id};
429 sub _remove_key_offset {
434 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
435 my ($loc, $trans_id, $is_deleted) = unpack(
436 "$self->{long_pack} C C",
437 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
440 if ( $trans_id == $args->{trans_id} ) {
441 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = '';
442 $args->{tag}{content} .= chr(0) x $self->{key_size};
449 $self->_storage->print_at(
450 $args->{tag}{offset}, $args->{tag}{content},
457 sub _add_key_offset {
462 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
463 my ($loc, $trans_id, $is_deleted) = unpack(
464 "$self->{long_pack} C C",
465 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
468 if ( $trans_id == $args->{trans_id} || (!$loc && !$is_deleted) ) {
469 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack(
470 "$self->{long_pack} C C",
471 $args->{loc}, $args->{trans_id}, 0,
479 $self->_storage->print_at(
480 $args->{tag}{offset}, $args->{tag}{content},
484 die "Why didn't _add_key_offset() change something?!\n";
494 # Need to remove use of $fh here
495 my $fh = $self->_storage->{fh};
498 #XXX The duplication of calculate_sizes needs to go away
499 unless ( $obj->{base_offset} ) {
500 my $bytes_read = $self->read_file_header;
502 $self->calculate_sizes;
505 # File is empty -- write header and master index
508 $self->_storage->audit( "# Database created on" );
510 $self->write_file_header;
512 $obj->{base_offset} = $self->_storage->request_space(
513 $self->tag_size( $self->{keyloc_size} ),
516 my $value_spot = $self->_storage->request_space(
517 $self->tag_size( $self->{index_size} ),
521 $obj->{base_offset}, SIG_KEYS,
522 pack( "$self->{long_pack} C C", $obj->{base_offset}, 0, 0 ),
523 chr(0) x ($self->{index_size} - $self->{long_size} + 2),
527 $value_spot, $obj->_type,
528 chr(0)x$self->{index_size},
531 # Flush the filehandle
532 my $old_fh = select $fh;
533 my $old_af = $|; $| = 1; $| = $old_af;
537 $obj->{base_offset} = $bytes_read;
540 # Get our type from master index header
542 my $tag = $self->load_tag($obj->_base_offset);
545 $self->_throw_error("Corrupted file, no master index record");
548 unless ($obj->_type eq $tag->{signature}) {
550 $self->_throw_error("File type mismatch");
555 $self->calculate_sizes;
558 #XXX We have to make sure we don't mess up when autoflush isn't turned on
559 $self->_storage->set_inode;