Commit | Line | Data |
a20d9a3f |
1 | package DBM::Deep::Engine; |
2 | |
460b1067 |
3 | use 5.6.0; |
4 | |
a20d9a3f |
5 | use strict; |
460b1067 |
6 | use warnings; |
a20d9a3f |
7 | |
8 | use Fcntl qw( :DEFAULT :flock :seek ); |
359a01ac |
9 | use Scalar::Util (); |
a20d9a3f |
10 | |
21838116 |
11 | # File-wide notes: |
12 | # * All the local($/,$\); are to protect read() and print() from -l. |
20b7f047 |
13 | # * To add to bucket_size, make sure you modify the following: |
14 | # - calculate_sizes() |
15 | # - _get_key_subloc() |
16 | # - add_bucket() - where the buckets are printed |
21838116 |
17 | |
8db25060 |
18 | ## |
19 | # Setup file and tag signatures. These should never change. |
20 | ## |
21 | sub SIG_FILE () { 'DPDB' } |
460b1067 |
22 | sub SIG_HEADER () { 'h' } |
8db25060 |
23 | sub SIG_INTERNAL () { 'i' } |
24 | sub SIG_HASH () { 'H' } |
25 | sub SIG_ARRAY () { 'A' } |
8db25060 |
26 | sub SIG_NULL () { 'N' } |
27 | sub SIG_DATA () { 'D' } |
28 | sub SIG_INDEX () { 'I' } |
29 | sub SIG_BLIST () { 'B' } |
7b1e1aa1 |
30 | sub SIG_FREE () { 'F' } |
8db25060 |
31 | sub SIG_SIZE () { 1 } |
32 | |
612969fb |
33 | sub new { |
34 | my $class = shift; |
35 | my ($args) = @_; |
36 | |
37 | my $self = bless { |
38 | long_size => 4, |
39 | long_pack => 'N', |
40 | data_size => 4, |
41 | data_pack => 'N', |
251dfd0e |
42 | |
612969fb |
43 | digest => \&Digest::MD5::md5, |
44 | hash_size => 16, |
251dfd0e |
45 | |
81d16922 |
46 | ## |
d5d7c51d |
47 | # Maximum number of buckets per list before another level of indexing is |
e0098e7f |
48 | # done. Increase this value for slightly greater speed, but larger database |
d5d7c51d |
49 | # files. DO NOT decrease this value below 16, due to risk of recursive |
50 | # reindex overrun. |
81d16922 |
51 | ## |
612969fb |
52 | max_buckets => 16, |
460b1067 |
53 | |
54 | fileobj => undef, |
359a01ac |
55 | obj => undef, |
612969fb |
56 | }, $class; |
57 | |
e0098e7f |
58 | if ( defined $args->{pack_size} ) { |
59 | if ( lc $args->{pack_size} eq 'small' ) { |
60 | $args->{long_size} = 2; |
c9b6d0d8 |
61 | $args->{long_pack} = 'n'; |
e0098e7f |
62 | } |
63 | elsif ( lc $args->{pack_size} eq 'medium' ) { |
64 | $args->{long_size} = 4; |
65 | $args->{long_pack} = 'N'; |
66 | } |
67 | elsif ( lc $args->{pack_size} eq 'large' ) { |
68 | $args->{long_size} = 8; |
69 | $args->{long_pack} = 'Q'; |
70 | } |
71 | else { |
72 | die "Unknown pack_size value: '$args->{pack_size}'\n"; |
73 | } |
74 | } |
75 | |
fde3db1a |
76 | # Grab the parameters we want to use |
77 | foreach my $param ( keys %$self ) { |
78 | next unless exists $args->{$param}; |
3e9498a1 |
79 | $self->{$param} = $args->{$param}; |
fde3db1a |
80 | } |
359a01ac |
81 | Scalar::Util::weaken( $self->{obj} ) if $self->{obj}; |
fde3db1a |
82 | |
e0098e7f |
83 | if ( $self->{max_buckets} < 16 ) { |
84 | warn "Floor of max_buckets is 16. Setting it to 16 from '$self->{max_buckets}'\n"; |
85 | $self->{max_buckets} = 16; |
86 | } |
87 | |
260a80b4 |
88 | return $self; |
89 | } |
90 | |
460b1067 |
91 | sub _fileobj { return $_[0]{fileobj} } |
92 | sub _fh { return $_[0]->_fileobj->{fh} } |
93 | |
260a80b4 |
94 | sub calculate_sizes { |
95 | my $self = shift; |
96 | |
28394a1a |
97 | #XXX Does this need to be updated with different hashing algorithms? |
e0098e7f |
98 | $self->{index_size} = (2**8) * $self->{long_size}; |
28394a1a |
99 | $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 3; |
e0098e7f |
100 | $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size}; |
612969fb |
101 | |
260a80b4 |
102 | return; |
1bf65be7 |
103 | } |
104 | |
fde3db1a |
105 | sub write_file_header { |
0d0f3d5d |
106 | my $self = shift; |
0d0f3d5d |
107 | |
019404df |
108 | my $loc = $self->_fileobj->request_space( length( SIG_FILE ) + 21 ); |
0d0f3d5d |
109 | |
019404df |
110 | $self->_fileobj->print_at( $loc, |
260a80b4 |
111 | SIG_FILE, |
460b1067 |
112 | SIG_HEADER, |
113 | pack('N', 1), # header version |
114 | pack('N', 12), # header size |
15ba72cc |
115 | pack('N', 0), # currently running transaction IDs |
c9b6d0d8 |
116 | pack('n', $self->{long_size}), |
260a80b4 |
117 | pack('A', $self->{long_pack}), |
c9b6d0d8 |
118 | pack('n', $self->{data_size}), |
260a80b4 |
119 | pack('A', $self->{data_pack}), |
c9b6d0d8 |
120 | pack('n', $self->{max_buckets}), |
260a80b4 |
121 | ); |
0d0f3d5d |
122 | |
20b7f047 |
123 | $self->_fileobj->set_transaction_offset( 13 ); |
124 | |
0d0f3d5d |
125 | return; |
126 | } |
127 | |
fde3db1a |
128 | sub read_file_header { |
e064ccd1 |
129 | my $self = shift; |
e064ccd1 |
130 | |
21838116 |
131 | local($/,$\); |
132 | |
e96daec8 |
133 | my $fh = $self->_fh; |
e064ccd1 |
134 | |
e96daec8 |
135 | seek($fh, 0 + $self->_fileobj->{file_offset}, SEEK_SET); |
42f79e07 |
136 | my $buffer; |
460b1067 |
137 | my $bytes_read = read( $fh, $buffer, length(SIG_FILE) + 9 ); |
138 | |
139 | return unless $bytes_read; |
140 | |
141 | my ($file_signature, $sig_header, $header_version, $size) = unpack( |
142 | 'A4 A N N', $buffer |
42f79e07 |
143 | ); |
e064ccd1 |
144 | |
460b1067 |
145 | unless ( $file_signature eq SIG_FILE ) { |
15ba72cc |
146 | $self->_fileobj->close; |
e96daec8 |
147 | $self->_throw_error( "Signature not found -- file is not a Deep DB" ); |
460b1067 |
148 | } |
260a80b4 |
149 | |
460b1067 |
150 | unless ( $sig_header eq SIG_HEADER ) { |
15ba72cc |
151 | $self->_fileobj->close; |
e96daec8 |
152 | $self->_throw_error( "Old file version found." ); |
460b1067 |
153 | } |
9b2370e0 |
154 | |
460b1067 |
155 | my $buffer2; |
156 | $bytes_read += read( $fh, $buffer2, $size ); |
c9b6d0d8 |
157 | my ($running_transactions, @values) = unpack( 'N n A n A n', $buffer2 ); |
15ba72cc |
158 | |
159 | $self->_fileobj->set_transaction_offset( 13 ); |
160 | |
460b1067 |
161 | if ( @values < 5 || grep { !defined } @values ) { |
15ba72cc |
162 | $self->_fileobj->close; |
e96daec8 |
163 | $self->_throw_error("Corrupted file - bad header"); |
e064ccd1 |
164 | } |
165 | |
460b1067 |
166 | #XXX Add warnings if values weren't set right |
167 | @{$self}{qw(long_size long_pack data_size data_pack max_buckets)} = @values; |
168 | |
e064ccd1 |
169 | return $bytes_read; |
170 | } |
171 | |
460b1067 |
172 | sub setup_fh { |
173 | my $self = shift; |
174 | my ($obj) = @_; |
70b55428 |
175 | |
359a01ac |
176 | local($/,$\); |
177 | |
e96daec8 |
178 | my $fh = $self->_fh; |
6fde4ed2 |
179 | flock $fh, LOCK_EX; |
118ba343 |
180 | |
260a80b4 |
181 | #XXX The duplication of calculate_sizes needs to go away |
6fde4ed2 |
182 | unless ( $obj->{base_offset} ) { |
e96daec8 |
183 | my $bytes_read = $self->read_file_header; |
118ba343 |
184 | |
260a80b4 |
185 | $self->calculate_sizes; |
186 | |
118ba343 |
187 | ## |
fde3db1a |
188 | # File is empty -- write header and master index |
118ba343 |
189 | ## |
190 | if (!$bytes_read) { |
aa83bc1e |
191 | $self->_fileobj->audit( "# Database created on" ); |
359a01ac |
192 | |
e96daec8 |
193 | $self->write_file_header; |
118ba343 |
194 | |
019404df |
195 | $obj->{base_offset} = $self->_fileobj->request_space( $self->tag_size( $self->{index_size} ) ); |
118ba343 |
196 | |
9e4f83a0 |
197 | $self->write_tag( |
e96daec8 |
198 | $obj->_base_offset, $obj->_type, |
f37c15ab |
199 | chr(0)x$self->{index_size}, |
118ba343 |
200 | ); |
201 | |
202 | # Flush the filehandle |
203 | my $old_fh = select $fh; |
204 | my $old_af = $|; $| = 1; $| = $old_af; |
205 | select $old_fh; |
206 | } |
207 | else { |
208 | $obj->{base_offset} = $bytes_read; |
209 | |
210 | ## |
fde3db1a |
211 | # Get our type from master index header |
118ba343 |
212 | ## |
359a01ac |
213 | my $tag = $self->load_tag($obj->_base_offset); |
214 | unless ( $tag ) { |
215 | flock $fh, LOCK_UN; |
216 | $self->_throw_error("Corrupted file, no master index record"); |
217 | } |
118ba343 |
218 | |
e96daec8 |
219 | unless ($obj->_type eq $tag->{signature}) { |
359a01ac |
220 | flock $fh, LOCK_UN; |
e96daec8 |
221 | $self->_throw_error("File type mismatch"); |
118ba343 |
222 | } |
223 | } |
118ba343 |
224 | } |
260a80b4 |
225 | else { |
226 | $self->calculate_sizes; |
227 | } |
e06824f8 |
228 | |
673464d9 |
229 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
e96daec8 |
230 | unless ( $self->_fileobj->{inode} ) { |
231 | my @stats = stat($fh); |
232 | $self->_fileobj->{inode} = $stats[1]; |
233 | $self->_fileobj->{end} = $stats[7]; |
70b55428 |
234 | } |
235 | |
6fde4ed2 |
236 | flock $fh, LOCK_UN; |
237 | |
70b55428 |
238 | return 1; |
239 | } |
240 | |
16d1ad9b |
241 | sub tag_size { |
242 | my $self = shift; |
243 | my ($size) = @_; |
244 | return SIG_SIZE + $self->{data_size} + $size; |
245 | } |
246 | |
9e4f83a0 |
247 | sub write_tag { |
20f7b20c |
248 | ## |
249 | # Given offset, signature and content, create tag and write to disk |
250 | ## |
d4b1166e |
251 | my $self = shift; |
e96daec8 |
252 | my ($offset, $sig, $content) = @_; |
f37c15ab |
253 | my $size = length( $content ); |
20f7b20c |
254 | |
21838116 |
255 | local($/,$\); |
256 | |
e96daec8 |
257 | my $fh = $self->_fh; |
d4b1166e |
258 | |
f37c15ab |
259 | if ( defined $offset ) { |
e96daec8 |
260 | seek($fh, $offset + $self->_fileobj->{file_offset}, SEEK_SET); |
f37c15ab |
261 | } |
262 | |
251dfd0e |
263 | print( $fh $sig . pack($self->{data_pack}, $size) . $content ); |
20f7b20c |
264 | |
f37c15ab |
265 | return unless defined $offset; |
266 | |
20f7b20c |
267 | return { |
268 | signature => $sig, |
269 | size => $size, |
8db25060 |
270 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
271 | content => $content |
272 | }; |
d4b1166e |
273 | } |
274 | |
275 | sub load_tag { |
20f7b20c |
276 | ## |
277 | # Given offset, load single tag and return signature, size and data |
278 | ## |
d4b1166e |
279 | my $self = shift; |
e96daec8 |
280 | my ($offset) = @_; |
20f7b20c |
281 | |
21838116 |
282 | local($/,$\); |
283 | |
e96daec8 |
284 | my $fh = $self->_fh; |
d4b1166e |
285 | |
e96daec8 |
286 | seek($fh, $offset + $self->_fileobj->{file_offset}, SEEK_SET); |
e5fc7e69 |
287 | |
75be6413 |
288 | #XXX I'm not sure this check will work if autoflush isn't enabled ... |
e5fc7e69 |
289 | return if eof $fh; |
20f7b20c |
290 | |
d4b1166e |
291 | my $b; |
8db25060 |
292 | read( $fh, $b, SIG_SIZE + $self->{data_size} ); |
251dfd0e |
293 | my ($sig, $size) = unpack( "A $self->{data_pack}", $b ); |
20f7b20c |
294 | |
295 | my $buffer; |
296 | read( $fh, $buffer, $size); |
297 | |
298 | return { |
299 | signature => $sig, |
300 | size => $size, |
8db25060 |
301 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
302 | content => $buffer |
303 | }; |
d4b1166e |
304 | } |
305 | |
56ec4340 |
306 | sub _get_dbm_object { |
307 | my $item = shift; |
308 | |
309 | my $obj = eval { |
310 | local $SIG{__DIE__}; |
311 | if ($item->isa( 'DBM::Deep' )) { |
312 | return $item; |
313 | } |
314 | return; |
315 | }; |
316 | return $obj if $obj; |
317 | |
318 | my $r = Scalar::Util::reftype( $item ) || ''; |
319 | if ( $r eq 'HASH' ) { |
320 | my $obj = eval { |
321 | local $SIG{__DIE__}; |
322 | my $obj = tied(%$item); |
323 | if ($obj->isa( 'DBM::Deep' )) { |
324 | return $obj; |
325 | } |
326 | return; |
327 | }; |
328 | return $obj if $obj; |
329 | } |
330 | elsif ( $r eq 'ARRAY' ) { |
331 | my $obj = eval { |
332 | local $SIG{__DIE__}; |
333 | my $obj = tied(@$item); |
334 | if ($obj->isa( 'DBM::Deep' )) { |
335 | return $obj; |
336 | } |
337 | return; |
338 | }; |
339 | return $obj if $obj; |
340 | } |
341 | |
342 | return; |
343 | } |
344 | |
29b01632 |
345 | sub _length_needed { |
346 | my $self = shift; |
e96daec8 |
347 | my ($value, $key) = @_; |
29b01632 |
348 | |
349 | my $is_dbm_deep = eval { |
350 | local $SIG{'__DIE__'}; |
351 | $value->isa( 'DBM::Deep' ); |
352 | }; |
353 | |
f37c15ab |
354 | my $len = SIG_SIZE + $self->{data_size} |
355 | + $self->{data_size} + length( $key ); |
29b01632 |
356 | |
e96daec8 |
357 | if ( $is_dbm_deep && $value->_fileobj eq $self->_fileobj ) { |
f37c15ab |
358 | return $len + $self->{long_size}; |
29b01632 |
359 | } |
360 | |
361 | my $r = Scalar::Util::reftype( $value ) || ''; |
e96daec8 |
362 | if ( $self->_fileobj->{autobless} ) { |
9a187d8c |
363 | # This is for the bit saying whether or not this thing is blessed. |
364 | $len += 1; |
365 | } |
366 | |
29b01632 |
367 | unless ( $r eq 'HASH' || $r eq 'ARRAY' ) { |
f37c15ab |
368 | if ( defined $value ) { |
369 | $len += length( $value ); |
370 | } |
371 | return $len; |
29b01632 |
372 | } |
373 | |
f37c15ab |
374 | $len += $self->{index_size}; |
29b01632 |
375 | |
376 | # if autobless is enabled, must also take into consideration |
f37c15ab |
377 | # the class name as it is stored after the key. |
e96daec8 |
378 | if ( $self->_fileobj->{autobless} ) { |
56ec4340 |
379 | my $c = Scalar::Util::blessed($value); |
380 | if ( defined $c && !$is_dbm_deep ) { |
381 | $len += $self->{data_size} + length($c); |
29b01632 |
382 | } |
383 | } |
384 | |
f37c15ab |
385 | return $len; |
29b01632 |
386 | } |
387 | |
20f7b20c |
388 | sub add_bucket { |
389 | ## |
390 | # Adds one key/value pair to bucket list, given offset, MD5 digest of key, |
391 | # plain (undigested) key and value. |
392 | ## |
d4b1166e |
393 | my $self = shift; |
359a01ac |
394 | my ($tag, $md5, $plain_key, $value, $deleted, $orig_key) = @_; |
c9b6d0d8 |
395 | $deleted ||= 0; |
75be6413 |
396 | |
21838116 |
397 | local($/,$\); |
398 | |
eea0d863 |
399 | # This verifies that only supported values will be stored. |
400 | { |
401 | my $r = Scalar::Util::reftype( $value ); |
402 | last if !defined $r; |
403 | |
404 | last if $r eq 'HASH'; |
405 | last if $r eq 'ARRAY'; |
406 | |
e96daec8 |
407 | $self->_throw_error( |
eea0d863 |
408 | "Storage of variables of type '$r' is not supported." |
409 | ); |
410 | } |
411 | |
20f7b20c |
412 | my $location = 0; |
413 | my $result = 2; |
414 | |
019404df |
415 | my $fileobj = $self->_fileobj; |
20f7b20c |
416 | |
e96daec8 |
417 | my $actual_length = $self->_length_needed( $value, $plain_key ); |
20f7b20c |
418 | |
21838116 |
419 | #ACID - This is a mutation. Must only find the exact transaction |
c9b6d0d8 |
420 | my ($subloc, $offset, $size,$is_deleted) = $self->_find_in_buckets( $tag, $md5, 1 ); |
421 | |
422 | my @transactions; |
019404df |
423 | if ( $fileobj->transaction_id == 0 ) { |
424 | @transactions = $fileobj->current_transactions; |
c9b6d0d8 |
425 | } |
75be6413 |
426 | |
e96daec8 |
427 | # $self->_release_space( $size, $subloc ); |
386bab6c |
428 | # Updating a known md5 |
f9c33187 |
429 | #XXX This needs updating to use _release_space |
386bab6c |
430 | if ( $subloc ) { |
431 | $result = 1; |
20f7b20c |
432 | |
386bab6c |
433 | if ($actual_length <= $size) { |
434 | $location = $subloc; |
20f7b20c |
435 | } |
75be6413 |
436 | else { |
019404df |
437 | $location = $fileobj->request_space( $actual_length ); |
438 | |
439 | $fileobj->print_at( $tag->{offset} + $offset + $self->{hash_size}, |
440 | pack($self->{long_pack}, $location ), |
441 | pack($self->{long_pack}, $actual_length ), |
442 | pack('n n', $fileobj->transaction_id, $deleted ), |
386bab6c |
443 | ); |
75be6413 |
444 | } |
75be6413 |
445 | } |
386bab6c |
446 | # Adding a new md5 |
447 | elsif ( defined $offset ) { |
019404df |
448 | $location = $fileobj->request_space( $actual_length ); |
386bab6c |
449 | |
019404df |
450 | $fileobj->print_at( $tag->{offset} + $offset, |
451 | $md5, |
452 | pack($self->{long_pack}, $location ), |
453 | pack($self->{long_pack}, $actual_length ), |
454 | pack('n n', $fileobj->transaction_id, $deleted ), |
455 | ); |
c9b6d0d8 |
456 | |
457 | for ( @transactions ) { |
458 | my $tag2 = $self->load_tag( $tag->{offset} - SIG_SIZE - $self->{data_size} ); |
019404df |
459 | $fileobj->{transaction_id} = $_; |
359a01ac |
460 | $self->add_bucket( $tag2, $md5, '', '', 1, $orig_key ); |
019404df |
461 | $fileobj->{transaction_id} = 0; |
c9b6d0d8 |
462 | } |
386bab6c |
463 | } |
464 | # If bucket didn't fit into list, split into a new index level |
019404df |
465 | # split_index() will do the _fileobj->request_space() call |
386bab6c |
466 | else { |
e96daec8 |
467 | $location = $self->split_index( $md5, $tag ); |
386bab6c |
468 | } |
20f7b20c |
469 | |
359a01ac |
470 | $self->write_value( $location, $plain_key, $value, $orig_key ); |
d5d7c51d |
471 | |
472 | return $result; |
473 | } |
474 | |
475 | sub write_value { |
476 | my $self = shift; |
359a01ac |
477 | my ($location, $key, $value, $orig_key) = @_; |
d5d7c51d |
478 | |
21838116 |
479 | local($/,$\); |
480 | |
e96daec8 |
481 | my $fh = $self->_fh; |
482 | my $root = $self->_fileobj; |
d5d7c51d |
483 | |
9d4fa373 |
484 | my $dbm_deep_obj = _get_dbm_object( $value ); |
e96daec8 |
485 | if ( $dbm_deep_obj && $dbm_deep_obj->_fileobj ne $self->_fileobj ) { |
486 | $self->_throw_error( "Cannot cross-reference. Use export() instead" ); |
9d4fa373 |
487 | } |
d5d7c51d |
488 | |
489 | seek($fh, $location + $root->{file_offset}, SEEK_SET); |
490 | |
20f7b20c |
491 | ## |
d5d7c51d |
492 | # Write signature based on content type, set content length and write |
493 | # actual value. |
20f7b20c |
494 | ## |
9d4fa373 |
495 | my $r = Scalar::Util::reftype( $value ) || ''; |
496 | if ( $dbm_deep_obj ) { |
e96daec8 |
497 | $self->write_tag( undef, SIG_INTERNAL,pack($self->{long_pack}, $dbm_deep_obj->_base_offset) ); |
f37c15ab |
498 | } |
499 | elsif ($r eq 'HASH') { |
9d4fa373 |
500 | if ( !$dbm_deep_obj && tied %{$value} ) { |
e96daec8 |
501 | $self->_throw_error( "Cannot store something that is tied" ); |
019ab3a1 |
502 | } |
e96daec8 |
503 | $self->write_tag( undef, SIG_HASH, chr(0)x$self->{index_size} ); |
f37c15ab |
504 | } |
505 | elsif ($r eq 'ARRAY') { |
9d4fa373 |
506 | if ( !$dbm_deep_obj && tied @{$value} ) { |
e96daec8 |
507 | $self->_throw_error( "Cannot store something that is tied" ); |
019ab3a1 |
508 | } |
e96daec8 |
509 | $self->write_tag( undef, SIG_ARRAY, chr(0)x$self->{index_size} ); |
f37c15ab |
510 | } |
511 | elsif (!defined($value)) { |
e96daec8 |
512 | $self->write_tag( undef, SIG_NULL, '' ); |
d5d7c51d |
513 | } |
514 | else { |
e96daec8 |
515 | $self->write_tag( undef, SIG_DATA, $value ); |
d5d7c51d |
516 | } |
20f7b20c |
517 | |
d5d7c51d |
518 | ## |
519 | # Plain key is stored AFTER value, as keys are typically fetched less often. |
520 | ## |
521 | print( $fh pack($self->{data_pack}, length($key)) . $key ); |
20f7b20c |
522 | |
9a187d8c |
523 | # Internal references don't care about autobless |
9d4fa373 |
524 | return 1 if $dbm_deep_obj; |
9a187d8c |
525 | |
d5d7c51d |
526 | ## |
527 | # If value is blessed, preserve class name |
528 | ## |
529 | if ( $root->{autobless} ) { |
56ec4340 |
530 | my $c = Scalar::Util::blessed($value); |
531 | if ( defined $c && !$dbm_deep_obj ) { |
d5d7c51d |
532 | print( $fh chr(1) ); |
56ec4340 |
533 | print( $fh pack($self->{data_pack}, length($c)) . $c ); |
20f7b20c |
534 | } |
d5d7c51d |
535 | else { |
536 | print( $fh chr(0) ); |
20f7b20c |
537 | } |
d5d7c51d |
538 | } |
20f7b20c |
539 | |
d5d7c51d |
540 | ## |
56ec4340 |
541 | # Tie the passed in reference so that changes to it are reflected in the |
542 | # datafile. The use of $location as the base_offset will act as the |
543 | # the linkage between parent and child. |
544 | # |
545 | # The overall assignment is a hack around the fact that just tying doesn't |
546 | # store the values. This may not be the wrong thing to do. |
d5d7c51d |
547 | ## |
9d4fa373 |
548 | if ($r eq 'HASH') { |
549 | my %x = %$value; |
550 | tie %$value, 'DBM::Deep', { |
551 | base_offset => $location, |
460b1067 |
552 | fileobj => $root, |
359a01ac |
553 | parent => $self->{obj}, |
554 | parent_key => $orig_key, |
9d4fa373 |
555 | }; |
556 | %$value = %x; |
557 | } |
558 | elsif ($r eq 'ARRAY') { |
559 | my @x = @$value; |
560 | tie @$value, 'DBM::Deep', { |
561 | base_offset => $location, |
460b1067 |
562 | fileobj => $root, |
359a01ac |
563 | parent => $self->{obj}, |
564 | parent_key => $orig_key, |
9d4fa373 |
565 | }; |
566 | @$value = @x; |
20f7b20c |
567 | } |
d4b1166e |
568 | |
d5d7c51d |
569 | return 1; |
d4b1166e |
570 | } |
571 | |
75be6413 |
572 | sub split_index { |
573 | my $self = shift; |
e96daec8 |
574 | my ($md5, $tag) = @_; |
75be6413 |
575 | |
019404df |
576 | my $fileobj = $self->_fileobj; |
21838116 |
577 | |
019404df |
578 | my $loc = $fileobj->request_space( |
e96daec8 |
579 | $self->tag_size( $self->{index_size} ), |
16d1ad9b |
580 | ); |
581 | |
019404df |
582 | $fileobj->print_at( $tag->{ref_loc}, pack($self->{long_pack}, $loc) ); |
75be6413 |
583 | |
9e4f83a0 |
584 | my $index_tag = $self->write_tag( |
e96daec8 |
585 | $loc, SIG_INDEX, |
f37c15ab |
586 | chr(0)x$self->{index_size}, |
75be6413 |
587 | ); |
588 | |
019404df |
589 | my $newtag_loc = $fileobj->request_space( |
e96daec8 |
590 | $self->tag_size( $self->{bucket_list_size} ), |
f9c33187 |
591 | ); |
75be6413 |
592 | |
7b1e1aa1 |
593 | my $keys = $tag->{content} |
f9c33187 |
594 | . $md5 . pack($self->{long_pack}, $newtag_loc) |
28394a1a |
595 | . pack($self->{long_pack}, 0) # size |
20b7f047 |
596 | . pack($self->{long_pack}, 0); # transaction ID |
75be6413 |
597 | |
f9c33187 |
598 | my @newloc = (); |
75be6413 |
599 | BUCKET: |
600 | for (my $i = 0; $i <= $self->{max_buckets}; $i++) { |
9a187d8c |
601 | my ($key, $old_subloc, $size) = $self->_get_key_subloc( $keys, $i ); |
75be6413 |
602 | |
f9c33187 |
603 | die "[INTERNAL ERROR]: No key in split_index()\n" unless $key; |
604 | die "[INTERNAL ERROR]: No subloc in split_index()\n" unless $old_subloc; |
75be6413 |
605 | |
75be6413 |
606 | my $num = ord(substr($key, $tag->{ch} + 1, 1)); |
607 | |
f9c33187 |
608 | if ($newloc[$num]) { |
019404df |
609 | local($/,$\); |
610 | |
611 | my $fh = $self->_fh; |
612 | |
613 | seek($fh, $newloc[$num] + $fileobj->{file_offset}, SEEK_SET); |
75be6413 |
614 | my $subkeys; |
615 | read( $fh, $subkeys, $self->{bucket_list_size}); |
616 | |
f9c33187 |
617 | # This is looking for the first empty spot |
7b1e1aa1 |
618 | my ($subloc, $offset, $size) = $self->_find_in_buckets( |
f9c33187 |
619 | { content => $subkeys }, '', |
7b1e1aa1 |
620 | ); |
75be6413 |
621 | |
019404df |
622 | $fileobj->print_at( $newloc[$num] + $offset, $key . pack($self->{long_pack}, $old_subloc) ); |
7b1e1aa1 |
623 | |
624 | next; |
75be6413 |
625 | } |
75be6413 |
626 | |
019404df |
627 | my $loc = $fileobj->request_space( |
e96daec8 |
628 | $self->tag_size( $self->{bucket_list_size} ), |
7b1e1aa1 |
629 | ); |
2603d86e |
630 | |
019404df |
631 | $fileobj->print_at( |
632 | $index_tag->{offset} + ($num * $self->{long_size}), |
633 | pack($self->{long_pack}, $loc), |
634 | ); |
75be6413 |
635 | |
7b1e1aa1 |
636 | my $blist_tag = $self->write_tag( |
e96daec8 |
637 | $loc, SIG_BLIST, |
7b1e1aa1 |
638 | chr(0)x$self->{bucket_list_size}, |
639 | ); |
640 | |
019404df |
641 | $fileobj->print_at( $blist_tag->{offset}, $key . pack($self->{long_pack}, $old_subloc) ); |
7b1e1aa1 |
642 | |
f9c33187 |
643 | $newloc[$num] = $blist_tag->{offset}; |
7b1e1aa1 |
644 | } |
645 | |
646 | $self->_release_space( |
e96daec8 |
647 | $self->tag_size( $self->{bucket_list_size} ), |
7b1e1aa1 |
648 | $tag->{offset} - SIG_SIZE - $self->{data_size}, |
649 | ); |
75be6413 |
650 | |
f9c33187 |
651 | return $newtag_loc; |
75be6413 |
652 | } |
653 | |
8db25060 |
654 | sub read_from_loc { |
655 | my $self = shift; |
359a01ac |
656 | my ($subloc, $orig_key) = @_; |
8db25060 |
657 | |
21838116 |
658 | local($/,$\); |
659 | |
e96daec8 |
660 | my $fh = $self->_fh; |
8db25060 |
661 | |
662 | ## |
663 | # Found match -- seek to offset and read signature |
664 | ## |
665 | my $signature; |
e96daec8 |
666 | seek($fh, $subloc + $self->_fileobj->{file_offset}, SEEK_SET); |
8db25060 |
667 | read( $fh, $signature, SIG_SIZE); |
668 | |
669 | ## |
670 | # If value is a hash or array, return new DBM::Deep object with correct offset |
671 | ## |
672 | if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) { |
685e40f1 |
673 | my $new_obj = DBM::Deep->new({ |
359a01ac |
674 | type => $signature, |
8db25060 |
675 | base_offset => $subloc, |
e96daec8 |
676 | fileobj => $self->_fileobj, |
359a01ac |
677 | parent => $self->{obj}, |
678 | parent_key => $orig_key, |
685e40f1 |
679 | }); |
8db25060 |
680 | |
460b1067 |
681 | if ($new_obj->_fileobj->{autobless}) { |
8db25060 |
682 | ## |
683 | # Skip over value and plain key to see if object needs |
684 | # to be re-blessed |
685 | ## |
686 | seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR); |
687 | |
688 | my $size; |
c6ea6b6c |
689 | read( $fh, $size, $self->{data_size}); |
690 | $size = unpack($self->{data_pack}, $size); |
8db25060 |
691 | if ($size) { seek($fh, $size, SEEK_CUR); } |
692 | |
693 | my $bless_bit; |
694 | read( $fh, $bless_bit, 1); |
695 | if (ord($bless_bit)) { |
696 | ## |
697 | # Yes, object needs to be re-blessed |
698 | ## |
699 | my $class_name; |
c6ea6b6c |
700 | read( $fh, $size, $self->{data_size}); |
701 | $size = unpack($self->{data_pack}, $size); |
8db25060 |
702 | if ($size) { read( $fh, $class_name, $size); } |
685e40f1 |
703 | if ($class_name) { $new_obj = bless( $new_obj, $class_name ); } |
8db25060 |
704 | } |
705 | } |
706 | |
685e40f1 |
707 | return $new_obj; |
8db25060 |
708 | } |
709 | elsif ( $signature eq SIG_INTERNAL ) { |
710 | my $size; |
711 | read( $fh, $size, $self->{data_size}); |
712 | $size = unpack($self->{data_pack}, $size); |
713 | |
714 | if ( $size ) { |
715 | my $new_loc; |
716 | read( $fh, $new_loc, $size ); |
717 | $new_loc = unpack( $self->{long_pack}, $new_loc ); |
718 | |
359a01ac |
719 | return $self->read_from_loc( $new_loc, $orig_key ); |
8db25060 |
720 | } |
721 | else { |
722 | return; |
723 | } |
724 | } |
725 | ## |
726 | # Otherwise return actual value |
727 | ## |
460b1067 |
728 | elsif ( $signature eq SIG_DATA ) { |
8db25060 |
729 | my $size; |
730 | read( $fh, $size, $self->{data_size}); |
731 | $size = unpack($self->{data_pack}, $size); |
732 | |
733 | my $value = ''; |
734 | if ($size) { read( $fh, $value, $size); } |
735 | return $value; |
736 | } |
737 | |
738 | ## |
739 | # Key exists, but content is null |
740 | ## |
741 | return; |
742 | } |
743 | |
9020ee8c |
744 | sub get_bucket_value { |
beac1dff |
745 | ## |
746 | # Fetch single value given tag and MD5 digested key. |
747 | ## |
748 | my $self = shift; |
359a01ac |
749 | my ($tag, $md5, $orig_key) = @_; |
9020ee8c |
750 | |
21838116 |
751 | #ACID - This is a read. Can find exact or HEAD |
c9b6d0d8 |
752 | my ($subloc, $offset, $size,$is_deleted) = $self->_find_in_buckets( $tag, $md5 ); |
753 | if ( $subloc && !$is_deleted ) { |
359a01ac |
754 | return $self->read_from_loc( $subloc, $orig_key ); |
386bab6c |
755 | } |
beac1dff |
756 | return; |
9020ee8c |
757 | } |
ab0e4957 |
758 | |
759 | sub delete_bucket { |
beac1dff |
760 | ## |
761 | # Delete single key/value pair given tag and MD5 digested key. |
762 | ## |
763 | my $self = shift; |
a97c8f67 |
764 | my ($tag, $md5, $orig_key) = @_; |
ab0e4957 |
765 | |
21838116 |
766 | #ACID - This is a mutation. Must only find the exact transaction |
767 | my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5, 1 ); |
019404df |
768 | #XXX This needs _release_space() for the value and anything below |
386bab6c |
769 | if ( $subloc ) { |
019404df |
770 | $self->_fileobj->print_at( |
771 | $tag->{offset} + $offset, |
772 | substr($tag->{content}, $offset + $self->{bucket_size} ), |
773 | chr(0) x $self->{bucket_size}, |
774 | ); |
d0b74c17 |
775 | |
ab0e4957 |
776 | return 1; |
386bab6c |
777 | } |
beac1dff |
778 | return; |
ab0e4957 |
779 | } |
780 | |
912d50b1 |
781 | sub bucket_exists { |
beac1dff |
782 | ## |
783 | # Check existence of single key given tag and MD5 digested key. |
784 | ## |
785 | my $self = shift; |
e96daec8 |
786 | my ($tag, $md5) = @_; |
912d50b1 |
787 | |
21838116 |
788 | #ACID - This is a read. Can find exact or HEAD |
c9b6d0d8 |
789 | my ($subloc, $offset, $size, $is_deleted) = $self->_find_in_buckets( $tag, $md5 ); |
790 | return ($subloc && !$is_deleted) && 1; |
912d50b1 |
791 | } |
792 | |
6736c116 |
793 | sub find_bucket_list { |
beac1dff |
794 | ## |
795 | # Locate offset for bucket list, given digested key |
796 | ## |
797 | my $self = shift; |
e96daec8 |
798 | my ($offset, $md5, $args) = @_; |
d0b74c17 |
799 | $args = {} unless $args; |
800 | |
21838116 |
801 | local($/,$\); |
802 | |
beac1dff |
803 | ## |
804 | # Locate offset for bucket list using digest index system |
805 | ## |
e96daec8 |
806 | my $tag = $self->load_tag( $offset ) |
807 | or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
d0b74c17 |
808 | |
e5fc7e69 |
809 | my $ch = 0; |
8db25060 |
810 | while ($tag->{signature} ne SIG_BLIST) { |
d0b74c17 |
811 | my $num = ord substr($md5, $ch, 1); |
812 | |
813 | my $ref_loc = $tag->{offset} + ($num * $self->{long_size}); |
e96daec8 |
814 | $tag = $self->index_lookup( $tag, $num ); |
d0b74c17 |
815 | |
816 | if (!$tag) { |
29b01632 |
817 | return if !$args->{create}; |
d0b74c17 |
818 | |
019404df |
819 | my $loc = $self->_fileobj->request_space( |
e96daec8 |
820 | $self->tag_size( $self->{bucket_list_size} ), |
16d1ad9b |
821 | ); |
822 | |
019404df |
823 | $self->_fileobj->print_at( $ref_loc, pack($self->{long_pack}, $loc) ); |
d0b74c17 |
824 | |
9e4f83a0 |
825 | $tag = $self->write_tag( |
e96daec8 |
826 | $loc, SIG_BLIST, |
f37c15ab |
827 | chr(0)x$self->{bucket_list_size}, |
d5d7c51d |
828 | ); |
829 | |
830 | $tag->{ref_loc} = $ref_loc; |
831 | $tag->{ch} = $ch; |
832 | |
833 | last; |
d0b74c17 |
834 | } |
835 | |
16d1ad9b |
836 | $tag->{ch} = $ch++; |
d0b74c17 |
837 | $tag->{ref_loc} = $ref_loc; |
beac1dff |
838 | } |
d0b74c17 |
839 | |
beac1dff |
840 | return $tag; |
6736c116 |
841 | } |
842 | |
d0b74c17 |
843 | sub index_lookup { |
844 | ## |
845 | # Given index tag, lookup single entry in index and return . |
846 | ## |
847 | my $self = shift; |
e96daec8 |
848 | my ($tag, $index) = @_; |
d0b74c17 |
849 | |
850 | my $location = unpack( |
851 | $self->{long_pack}, |
852 | substr( |
853 | $tag->{content}, |
854 | $index * $self->{long_size}, |
855 | $self->{long_size}, |
856 | ), |
857 | ); |
858 | |
859 | if (!$location) { return; } |
860 | |
e96daec8 |
861 | return $self->load_tag( $location ); |
d0b74c17 |
862 | } |
863 | |
6736c116 |
864 | sub traverse_index { |
beac1dff |
865 | ## |
866 | # Scan index and recursively step into deeper levels, looking for next key. |
867 | ## |
6736c116 |
868 | my $self = shift; |
869 | my ($obj, $offset, $ch, $force_return_next) = @_; |
d0b74c17 |
870 | |
21838116 |
871 | local($/,$\); |
872 | |
e96daec8 |
873 | my $tag = $self->load_tag( $offset ); |
6736c116 |
874 | |
e96daec8 |
875 | my $fh = $self->_fh; |
d0b74c17 |
876 | |
8db25060 |
877 | if ($tag->{signature} ne SIG_BLIST) { |
beac1dff |
878 | my $content = $tag->{content}; |
e5fc7e69 |
879 | my $start = $obj->{return_next} ? 0 : ord(substr($obj->{prev_md5}, $ch, 1)); |
d0b74c17 |
880 | |
d5d7c51d |
881 | for (my $idx = $start; $idx < (2**8); $idx++) { |
e5fc7e69 |
882 | my $subloc = unpack( |
883 | $self->{long_pack}, |
e06824f8 |
884 | substr( |
885 | $content, |
886 | $idx * $self->{long_size}, |
887 | $self->{long_size}, |
888 | ), |
e5fc7e69 |
889 | ); |
890 | |
beac1dff |
891 | if ($subloc) { |
e5fc7e69 |
892 | my $result = $self->traverse_index( |
893 | $obj, $subloc, $ch + 1, $force_return_next, |
894 | ); |
895 | |
beac1dff |
896 | if (defined($result)) { return $result; } |
897 | } |
898 | } # index loop |
d0b74c17 |
899 | |
beac1dff |
900 | $obj->{return_next} = 1; |
901 | } # tag is an index |
d0b74c17 |
902 | |
e5fc7e69 |
903 | else { |
beac1dff |
904 | my $keys = $tag->{content}; |
905 | if ($force_return_next) { $obj->{return_next} = 1; } |
d0b74c17 |
906 | |
beac1dff |
907 | ## |
908 | # Iterate through buckets, looking for a key match |
909 | ## |
8db25060 |
910 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
9cec1360 |
911 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
d0b74c17 |
912 | |
8db25060 |
913 | # End of bucket list -- return to outer loop |
beac1dff |
914 | if (!$subloc) { |
beac1dff |
915 | $obj->{return_next} = 1; |
916 | last; |
917 | } |
8db25060 |
918 | # Located previous key -- return next one found |
beac1dff |
919 | elsif ($key eq $obj->{prev_md5}) { |
beac1dff |
920 | $obj->{return_next} = 1; |
921 | next; |
922 | } |
8db25060 |
923 | # Seek to bucket location and skip over signature |
beac1dff |
924 | elsif ($obj->{return_next}) { |
e96daec8 |
925 | seek($fh, $subloc + $self->_fileobj->{file_offset}, SEEK_SET); |
d0b74c17 |
926 | |
beac1dff |
927 | # Skip over value to get to plain key |
8db25060 |
928 | my $sig; |
929 | read( $fh, $sig, SIG_SIZE ); |
930 | |
beac1dff |
931 | my $size; |
e5fc7e69 |
932 | read( $fh, $size, $self->{data_size}); |
933 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
934 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
935 | |
beac1dff |
936 | # Read in plain key and return as scalar |
beac1dff |
937 | my $plain_key; |
e5fc7e69 |
938 | read( $fh, $size, $self->{data_size}); |
939 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
940 | if ($size) { read( $fh, $plain_key, $size); } |
d0b74c17 |
941 | |
beac1dff |
942 | return $plain_key; |
943 | } |
8db25060 |
944 | } |
d0b74c17 |
945 | |
beac1dff |
946 | $obj->{return_next} = 1; |
947 | } # tag is a bucket list |
d0b74c17 |
948 | |
beac1dff |
949 | return; |
6736c116 |
950 | } |
951 | |
952 | sub get_next_key { |
beac1dff |
953 | ## |
954 | # Locate next key, given digested previous one |
955 | ## |
6736c116 |
956 | my $self = shift; |
957 | my ($obj) = @_; |
d0b74c17 |
958 | |
beac1dff |
959 | $obj->{prev_md5} = $_[1] ? $_[1] : undef; |
960 | $obj->{return_next} = 0; |
d0b74c17 |
961 | |
beac1dff |
962 | ## |
963 | # If the previous key was not specifed, start at the top and |
964 | # return the first one found. |
965 | ## |
966 | if (!$obj->{prev_md5}) { |
967 | $obj->{prev_md5} = chr(0) x $self->{hash_size}; |
968 | $obj->{return_next} = 1; |
969 | } |
d0b74c17 |
970 | |
beac1dff |
971 | return $self->traverse_index( $obj, $obj->_base_offset, 0 ); |
6736c116 |
972 | } |
973 | |
75be6413 |
974 | # Utilities |
975 | |
9cec1360 |
976 | sub _get_key_subloc { |
75be6413 |
977 | my $self = shift; |
978 | my ($keys, $idx) = @_; |
979 | |
c9b6d0d8 |
980 | my ($key, $subloc, $size, $transaction_id, $is_deleted) = unpack( |
28394a1a |
981 | # This is 'a', not 'A'. Please read the pack() documentation for the |
982 | # difference between the two and why it's important. |
c9b6d0d8 |
983 | "a$self->{hash_size} $self->{long_pack}2 n2", |
75be6413 |
984 | substr( |
985 | $keys, |
9cec1360 |
986 | ($idx * $self->{bucket_size}), |
987 | $self->{bucket_size}, |
75be6413 |
988 | ), |
989 | ); |
990 | |
c9b6d0d8 |
991 | return ($key, $subloc, $size, $transaction_id, $is_deleted); |
75be6413 |
992 | } |
993 | |
d608b06e |
994 | sub _find_in_buckets { |
995 | my $self = shift; |
21838116 |
996 | my ($tag, $md5, $exact) = @_; |
d608b06e |
997 | |
28394a1a |
998 | my $trans_id = $self->_fileobj->transaction_id; |
999 | |
21838116 |
1000 | my @zero; |
1001 | |
d608b06e |
1002 | BUCKET: |
1003 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
c9b6d0d8 |
1004 | my ($key, $subloc, $size, $transaction_id, $is_deleted) = $self->_get_key_subloc( |
9a187d8c |
1005 | $tag->{content}, $i, |
1006 | ); |
d608b06e |
1007 | |
c9b6d0d8 |
1008 | my @rv = ($subloc, $i * $self->{bucket_size}, $size, $is_deleted); |
21838116 |
1009 | |
1010 | unless ( $subloc ) { |
20b7f047 |
1011 | if ( !$exact && @zero and $trans_id ) { |
c9b6d0d8 |
1012 | @rv = ($zero[2], $zero[0] * $self->{bucket_size},$zero[3],$is_deleted); |
20b7f047 |
1013 | } |
21838116 |
1014 | return @rv; |
1015 | } |
1016 | |
1017 | next BUCKET if $key ne $md5; |
d608b06e |
1018 | |
21838116 |
1019 | # Save off the HEAD in case we need it. |
c9b6d0d8 |
1020 | @zero = ($i,$key,$subloc,$size,$transaction_id,$is_deleted) if $transaction_id == 0; |
d608b06e |
1021 | |
21838116 |
1022 | next BUCKET if $transaction_id != $trans_id; |
1023 | |
1024 | return @rv; |
d608b06e |
1025 | } |
1026 | |
1027 | return; |
1028 | } |
1029 | |
994ccd8e |
1030 | sub _release_space { |
1031 | my $self = shift; |
e96daec8 |
1032 | my ($size, $loc) = @_; |
994ccd8e |
1033 | |
7b1e1aa1 |
1034 | my $next_loc = 0; |
1035 | |
019404df |
1036 | $self->_fileobj->print_at( $loc, |
1037 | SIG_FREE, |
1038 | pack($self->{long_pack}, $size ), |
1039 | pack($self->{long_pack}, $next_loc ), |
7b1e1aa1 |
1040 | ); |
1041 | |
994ccd8e |
1042 | return; |
1043 | } |
1044 | |
e96daec8 |
1045 | sub _throw_error { |
1046 | die "DBM::Deep: $_[1]\n"; |
1047 | } |
1048 | |
a20d9a3f |
1049 | 1; |
1050 | __END__ |
d5d7c51d |
1051 | |
1052 | # This will be added in later, after more refactoring is done. This is an early |
1053 | # attempt at refactoring on the physical level instead of the virtual level. |
1054 | sub _read_at { |
1055 | my $self = shift; |
e96daec8 |
1056 | my ($spot, $amount, $unpack) = @_; |
d5d7c51d |
1057 | |
21838116 |
1058 | local($/,$\); |
1059 | |
e96daec8 |
1060 | my $fh = $self->_fh; |
1061 | seek( $fh, $spot + $self->_fileobj->{file_offset}, SEEK_SET ); |
d5d7c51d |
1062 | |
1063 | my $buffer; |
1064 | my $bytes_read = read( $fh, $buffer, $amount ); |
1065 | |
1066 | if ( $unpack ) { |
1067 | $buffer = unpack( $unpack, $buffer ); |
1068 | } |
1069 | |
1070 | if ( wantarray ) { |
1071 | return ($buffer, $bytes_read); |
1072 | } |
1073 | else { |
1074 | return $buffer; |
1075 | } |
1076 | } |
e96daec8 |
1077 | |
e96daec8 |
1078 | sub get_file_version { |
1079 | my $self = shift; |
1080 | |
21838116 |
1081 | local($/,$\); |
1082 | |
e96daec8 |
1083 | my $fh = $self->_fh; |
1084 | |
1085 | seek( $fh, 13 + $self->_fileobj->{file_offset}, SEEK_SET ); |
1086 | my $buffer; |
1087 | my $bytes_read = read( $fh, $buffer, 4 ); |
1088 | unless ( $bytes_read == 4 ) { |
1089 | $self->_throw_error( "Cannot read file version" ); |
1090 | } |
1091 | |
1092 | return unpack( 'N', $buffer ); |
1093 | } |
1094 | |
1095 | sub write_file_version { |
1096 | my $self = shift; |
1097 | my ($new_version) = @_; |
1098 | |
21838116 |
1099 | local($/,$\); |
1100 | |
e96daec8 |
1101 | my $fh = $self->_fh; |
1102 | |
1103 | seek( $fh, 13 + $self->_fileobj->{file_offset}, SEEK_SET ); |
1104 | print( $fh pack( 'N', $new_version ) ); |
1105 | |
1106 | return; |
1107 | } |
1108 | |