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_tag) = $self->_find_key_offset({
51 offset => $_val_offset,
52 key_md5 => $self->_apply_digest( $key ),
56 my ($val_offset, $is_del) = $self->_find_value_offset({
57 offset => $key_tag->{start},
58 trans_id => $trans_id,
62 die "Internal error!" if !$val_offset;
64 return $self->_read_value({
65 keyloc => $key_tag->{start},
66 offset => $val_offset,
73 my ($trans_id, $base_offset, $key) = @_;
75 my ($_val_offset, $_is_del) = $self->_find_value_offset({
76 offset => $base_offset,
77 trans_id => $trans_id,
80 die "Attempt to use a deleted value" if $_is_del;
81 die "Internal error!" if !$_val_offset;
83 my ($key_tag) = $self->_find_key_offset({
84 offset => $_val_offset,
85 key_md5 => $self->_apply_digest( $key ),
87 return '' if !$key_tag->{start};
89 my ($val_offset, $is_del) = $self->_find_value_offset({
90 offset => $key_tag->{start},
91 trans_id => $trans_id,
94 die "Internal error!" if !$_val_offset;
103 my ($trans_id, $base_offset) = @_;
105 my ($_val_offset, $_is_del) = $self->_find_value_offset({
106 offset => $base_offset,
107 trans_id => $trans_id,
110 die "Attempt to use a deleted value" if $_is_del;
111 die "Internal error!" if !$_val_offset;
113 # If the previous key was not specifed, start at the top and
114 # return the first one found.
118 prev_md5 => $self->_apply_digest($_[2]),
124 prev_md5 => chr(0) x $self->{hash_size},
130 print "get_next_key: $_val_offset\n" if $::DEBUG;
131 return $self->traverse_index( $temp, $_val_offset, 0 );
136 my ($trans_id, $base_offset, $key) = @_;
138 my ($_val_offset, $_is_del) = $self->_find_value_offset({
139 offset => $base_offset,
140 trans_id => $trans_id,
143 die "Attempt to use a deleted value" if $_is_del;
144 die "Internal error!" if !$_val_offset;
146 my ($key_tag, $bucket_tag) = $self->_find_key_offset({
147 offset => $_val_offset,
148 key_md5 => $self->_apply_digest( $key ),
150 return if !$key_tag->{start};
152 my $value = $self->read_value( $trans_id, $base_offset, $key );
153 my $value = $self->read_value( $trans_id, $base_offset, $key );
155 $self->_mark_as_deleted({
157 trans_id => $trans_id,
161 if ( my @transactions = $self->_storage->current_transactions ) {
162 foreach my $other_trans_id ( @transactions ) {
163 next if $self->_has_keyloc_entry({
165 trans_id => $other_trans_id,
167 $self->write_value( $other_trans_id, $base_offset, $key, $value );
171 $self->_mark_as_deleted({
173 trans_id => $trans_id,
175 # $self->_remove_key_offset({
176 # offset => $_val_offset,
177 # key_md5 => $self->_apply_digest( $key ),
186 my ($trans_id, $base_offset, $key, $value) = @_;
188 # This verifies that only supported values will be stored.
190 my $r = Scalar::Util::reftype( $value );
193 last if $r eq 'HASH';
194 last if $r eq 'ARRAY';
197 "Storage of references of type '$r' is not supported."
201 my ($_val_offset, $_is_del) = $self->_find_value_offset({
202 offset => $base_offset,
203 trans_id => $trans_id,
206 die "Attempt to use a deleted value" if $_is_del;
207 die "Internal error!" if !$_val_offset;
209 my ($key_tag, $bucket_tag) = $self->_find_key_offset({
210 offset => $_val_offset,
211 key_md5 => $self->_apply_digest( $key ),
214 die "Cannot find/create new key offset!" if !$key_tag->{start};
217 if ( $key_tag->{is_new} ) {
218 # Must mark the HEAD as deleted because it doesn't exist
219 $self->_mark_as_deleted({
226 # If the HEAD isn't new, then we must take other transactions
227 # into account. If it is, then there can be no other transactions.
228 if ( !$key_tag->{is_new} ) {
229 my $old_value = $self->read_value( $trans_id, $base_offset, $key );
230 if ( my @transactions = $self->_storage->current_transactions ) {
231 foreach my $other_trans_id ( @transactions ) {
232 next if $self->_has_keyloc_entry({
234 trans_id => $other_trans_id,
236 $self->write_value( $other_trans_id, $base_offset, $key, $old_value );
242 my $value_loc = $self->_storage->request_space(
243 $self->_length_needed( $value, $key ),
246 $self->_add_key_offset({
248 trans_id => $trans_id,
252 $self->_write_value( $key_tag->{start}, $value_loc, $key, $value, $key );
257 sub _find_value_offset {
261 my $key_tag = $self->load_tag( $args->{offset} );
264 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
265 my ($loc, $trans_id, $is_deleted) = unpack(
266 "$self->{long_pack} C C",
267 substr( $key_tag->{content}, $i * $self->{key_size}, $self->{key_size} ),
270 if ( $trans_id == HEAD ) {
271 @head = ($loc, $is_deleted);
274 next if $loc && $args->{trans_id} != $trans_id;
275 return( $loc, $is_deleted );
278 return @head if $args->{allow_head};
282 sub _find_key_offset {
286 my $bucket_tag = $self->load_tag( $args->{offset} )
287 or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" );
289 #XXX What happens when $ch >= $self->{hash_size} ??
290 for (my $ch = 0; $bucket_tag->{signature} ne SIG_BLIST; $ch++) {
291 my $num = ord substr($args->{key_md5}, $ch, 1);
293 my $ref_loc = $bucket_tag->{offset} + ($num * $self->{long_size});
294 $bucket_tag = $self->index_lookup( $bucket_tag, $num );
297 return if !$args->{create};
299 my $loc = $self->_storage->request_space(
300 $self->tag_size( $self->{bucket_list_size} ),
303 $self->_storage->print_at( $ref_loc, pack($self->{long_pack}, $loc) );
305 $bucket_tag = $self->write_tag(
307 chr(0)x$self->{bucket_list_size},
310 $bucket_tag->{ref_loc} = $ref_loc;
311 $bucket_tag->{ch} = $ch;
312 $bucket_tag->{is_new} = 1;
317 $bucket_tag->{ch} = $ch;
318 $bucket_tag->{ref_loc} = $ref_loc;
321 # Need to create a new keytag, too
322 if ( $bucket_tag->{is_new} ) {
323 my $keytag_loc = $self->_storage->request_space(
324 $self->tag_size( $self->{keyloc_size} ),
327 substr( $bucket_tag->{content}, 0, $self->{key_size} ) =
328 $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc );
330 $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} );
332 my $key_tag = $self->write_tag(
333 $keytag_loc, SIG_KEYS,
334 chr(0)x$self->{keyloc_size},
337 return( $key_tag, $bucket_tag );
340 my ($key, $subloc, $index);
342 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
343 ($key, $subloc) = $self->_get_key_subloc(
344 $bucket_tag->{content}, $i,
347 next BUCKET if $subloc && $key ne $args->{key_md5};
349 # Keep track of where we are, in case we need to create a new
355 # If we have a subloc to return or we don't want to create a new
356 # entry, we need to return now.
357 $args->{create} ||= 0;
358 return ($self->load_tag( $subloc ), $bucket_tag) if $subloc || !$args->{create};
360 my $keytag_loc = $self->_storage->request_space(
361 $self->tag_size( $self->{keyloc_size} ),
364 # There's space left in this bucket
365 if ( defined $index ) {
366 substr( $bucket_tag->{content}, $index * $self->{key_size}, $self->{key_size} ) =
367 $args->{key_md5} . pack( "$self->{long_pack}", $keytag_loc );
369 $self->_storage->print_at( $bucket_tag->{offset}, $bucket_tag->{content} );
371 # We need to split the index
373 $self->split_index( $bucket_tag, $args->{key_md5}, $keytag_loc );
376 my $key_tag = $self->write_tag(
377 $keytag_loc, SIG_KEYS,
378 chr(0)x$self->{keyloc_size},
381 return( $key_tag, $bucket_tag );
391 return $self->read_from_loc( $args->{keyloc}, $args->{offset}, $args->{key} );
394 sub _mark_as_deleted {
399 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
400 my ($loc, $trans_id, $is_deleted) = unpack(
401 "$self->{long_pack} C C",
402 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
405 last unless $loc || $is_deleted;
407 if ( $trans_id == $args->{trans_id} ) {
408 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack(
409 "$self->{long_pack} C C",
418 $self->_storage->print_at(
419 $args->{tag}{offset}, $args->{tag}{content},
426 sub _has_keyloc_entry {
430 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
431 my ($loc, $trans_id, $is_deleted) = unpack(
432 "$self->{long_pack} C C",
433 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
436 return 1 if $trans_id == $args->{trans_id};
442 sub _remove_key_offset {
447 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
448 my ($loc, $trans_id, $is_deleted) = unpack(
449 "$self->{long_pack} C C",
450 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
453 if ( $trans_id == $args->{trans_id} ) {
454 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = '';
455 $args->{tag}{content} .= chr(0) x $self->{key_size};
462 $self->_storage->print_at(
463 $args->{tag}{offset}, $args->{tag}{content},
470 sub _add_key_offset {
475 for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) {
476 my ($loc, $trans_id, $is_deleted) = unpack(
477 "$self->{long_pack} C C",
478 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ),
481 if ( $trans_id == $args->{trans_id} || (!$loc && !$is_deleted) ) {
482 substr( $args->{tag}{content}, $i * $self->{key_size}, $self->{key_size} ) = pack(
483 "$self->{long_pack} C C",
484 $args->{loc}, $args->{trans_id}, 0,
492 $self->_storage->print_at(
493 $args->{tag}{offset}, $args->{tag}{content},
497 die "Why didn't _add_key_offset() change something?!\n";
507 # Need to remove use of $fh here
508 my $fh = $self->_storage->{fh};
511 #XXX The duplication of calculate_sizes needs to go away
512 unless ( $obj->{base_offset} ) {
513 my $bytes_read = $self->read_file_header;
515 $self->calculate_sizes;
518 # File is empty -- write header and master index
521 $self->_storage->audit( "# Database created on" );
523 $self->write_file_header;
525 $obj->{base_offset} = $self->_storage->request_space(
526 $self->tag_size( $self->{keyloc_size} ),
529 my $value_spot = $self->_storage->request_space(
530 $self->tag_size( $self->{index_size} ),
534 $obj->{base_offset}, SIG_KEYS,
535 pack( "$self->{long_pack} C C", $value_spot, HEAD, 0 ),
536 chr(0) x ($self->{index_size} - $self->{key_size}),
540 $value_spot, $obj->_type,
541 chr(0)x$self->{index_size},
544 # Flush the filehandle
545 my $old_fh = select $fh;
546 my $old_af = $|; $| = 1; $| = $old_af;
550 $obj->{base_offset} = $bytes_read;
552 my ($_val_offset, $_is_del) = $self->_find_value_offset({
553 offset => $obj->{base_offset},
557 die "Attempt to use a deleted value" if $_is_del;
558 die "Internal error!" if !$_val_offset;
561 # Get our type from master index header
563 my $tag = $self->load_tag($_val_offset);
566 $self->_throw_error("Corrupted file, no master index record");
569 unless ($obj->_type eq $tag->{signature}) {
571 $self->_throw_error("File type mismatch");
576 $self->calculate_sizes;
579 #XXX We have to make sure we don't mess up when autoflush isn't turned on
580 $self->_storage->set_inode;