Commit | Line | Data |
a20d9a3f |
1 | package DBM::Deep::Engine; |
2 | |
3 | use strict; |
4 | |
5 | use Fcntl qw( :DEFAULT :flock :seek ); |
6 | |
8db25060 |
7 | ## |
8 | # Setup file and tag signatures. These should never change. |
9 | ## |
10 | sub SIG_FILE () { 'DPDB' } |
11 | sub SIG_INTERNAL () { 'i' } |
12 | sub SIG_HASH () { 'H' } |
13 | sub SIG_ARRAY () { 'A' } |
8db25060 |
14 | sub SIG_NULL () { 'N' } |
15 | sub SIG_DATA () { 'D' } |
16 | sub SIG_INDEX () { 'I' } |
17 | sub SIG_BLIST () { 'B' } |
18 | sub SIG_SIZE () { 1 } |
19 | |
612969fb |
20 | sub precalc_sizes { |
beac1dff |
21 | ## |
22 | # Precalculate index, bucket and bucket list sizes |
23 | ## |
251dfd0e |
24 | my $self = shift; |
1bf65be7 |
25 | |
251dfd0e |
26 | $self->{index_size} = (2**8) * $self->{long_size}; |
27 | $self->{bucket_size} = $self->{hash_size} + $self->{long_size}; |
28 | $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size}; |
1bf65be7 |
29 | |
251dfd0e |
30 | return 1; |
1bf65be7 |
31 | } |
32 | |
33 | sub set_pack { |
beac1dff |
34 | ## |
35 | # Set pack/unpack modes (see file header for more) |
36 | ## |
251dfd0e |
37 | my $self = shift; |
1bf65be7 |
38 | my ($long_s, $long_p, $data_s, $data_p) = @_; |
39 | |
81d16922 |
40 | ## |
75be6413 |
41 | # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4 |
42 | # GB per file. |
beac1dff |
43 | # (Perl must be compiled with largefile support for files > 2 GB) |
81d16922 |
44 | # |
45 | # Set to 8 and 'Q' for 64-bit offsets. Theoretical limit of 16 XB per file. |
beac1dff |
46 | # (Perl must be compiled with largefile and 64-bit long support) |
81d16922 |
47 | ## |
251dfd0e |
48 | $self->{long_size} = $long_s ? $long_s : 4; |
49 | $self->{long_pack} = $long_p ? $long_p : 'N'; |
1bf65be7 |
50 | |
81d16922 |
51 | ## |
75be6413 |
52 | # Set to 4 and 'N' for 32-bit data length prefixes. Limit of 4 GB for each |
d5d7c51d |
53 | # key/value. Upgrading this is possible (see above) but probably not |
54 | # necessary. If you need more than 4 GB for a single key or value, this |
55 | # module is really not for you :-) |
81d16922 |
56 | ## |
251dfd0e |
57 | $self->{data_size} = $data_s ? $data_s : 4; |
58 | $self->{data_pack} = $data_p ? $data_p : 'N'; |
1bf65be7 |
59 | |
beac1dff |
60 | return $self->precalc_sizes(); |
1bf65be7 |
61 | } |
62 | |
63 | sub set_digest { |
beac1dff |
64 | ## |
65 | # Set key digest function (default is MD5) |
66 | ## |
251dfd0e |
67 | my $self = shift; |
1bf65be7 |
68 | my ($digest_func, $hash_size) = @_; |
69 | |
d0b74c17 |
70 | $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5; |
251dfd0e |
71 | $self->{hash_size} = $hash_size ? $hash_size : 16; |
612969fb |
72 | |
beac1dff |
73 | return $self->precalc_sizes(); |
612969fb |
74 | } |
75 | |
76 | sub new { |
77 | my $class = shift; |
78 | my ($args) = @_; |
79 | |
80 | my $self = bless { |
81 | long_size => 4, |
82 | long_pack => 'N', |
83 | data_size => 4, |
84 | data_pack => 'N', |
251dfd0e |
85 | |
612969fb |
86 | digest => \&Digest::MD5::md5, |
87 | hash_size => 16, |
251dfd0e |
88 | |
81d16922 |
89 | ## |
d5d7c51d |
90 | # Maximum number of buckets per list before another level of indexing is |
91 | # done. |
92 | # Increase this value for slightly greater speed, but larger database |
93 | # files. DO NOT decrease this value below 16, due to risk of recursive |
94 | # reindex overrun. |
81d16922 |
95 | ## |
612969fb |
96 | max_buckets => 16, |
97 | }, $class; |
98 | |
251dfd0e |
99 | $self->precalc_sizes; |
612969fb |
100 | |
101 | return $self; |
1bf65be7 |
102 | } |
103 | |
70b55428 |
104 | sub setup_fh { |
105 | my $self = shift; |
106 | my ($obj) = @_; |
107 | |
108 | $self->open( $obj ) if !defined $obj->_fh; |
109 | |
6fde4ed2 |
110 | my $fh = $obj->_fh; |
111 | flock $fh, LOCK_EX; |
118ba343 |
112 | |
6fde4ed2 |
113 | unless ( $obj->{base_offset} ) { |
118ba343 |
114 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
115 | my $signature; |
116 | my $bytes_read = read( $fh, $signature, length(SIG_FILE)); |
117 | |
118 | ## |
119 | # File is empty -- write signature and master index |
120 | ## |
121 | if (!$bytes_read) { |
c9ec091a |
122 | my $loc = $self->_request_space( $obj, length( SIG_FILE ) ); |
123 | seek($fh, $loc + $obj->_root->{file_offset}, SEEK_SET); |
118ba343 |
124 | print( $fh SIG_FILE); |
125 | |
c9ec091a |
126 | $obj->{base_offset} = $self->_request_space( |
127 | $obj, $self->{index_size}, |
128 | ); |
118ba343 |
129 | |
130 | $self->create_tag( |
c9ec091a |
131 | $obj, $obj->_base_offset, $obj->_type, |
132 | chr(0) x $self->{index_size}, |
118ba343 |
133 | ); |
134 | |
135 | # Flush the filehandle |
136 | my $old_fh = select $fh; |
137 | my $old_af = $|; $| = 1; $| = $old_af; |
138 | select $old_fh; |
139 | } |
140 | else { |
141 | $obj->{base_offset} = $bytes_read; |
142 | |
143 | ## |
144 | # Check signature was valid |
145 | ## |
146 | unless ($signature eq SIG_FILE) { |
147 | $self->close_fh( $obj ); |
148 | $obj->_throw_error("Signature not found -- file is not a Deep DB"); |
149 | } |
150 | |
151 | ## |
152 | # Get our type from master index signature |
153 | ## |
154 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
155 | or $obj->_throw_error("Corrupted file, no master index record"); |
156 | |
157 | unless ($obj->{type} eq $tag->{signature}) { |
158 | $obj->_throw_error("File type mismatch"); |
159 | } |
160 | } |
118ba343 |
161 | } |
e06824f8 |
162 | |
673464d9 |
163 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
70b55428 |
164 | unless ( $obj->_root->{inode} ) { |
165 | my @stats = stat($obj->_fh); |
166 | $obj->_root->{inode} = $stats[1]; |
167 | $obj->_root->{end} = $stats[7]; |
168 | } |
169 | |
6fde4ed2 |
170 | flock $fh, LOCK_UN; |
171 | |
70b55428 |
172 | return 1; |
173 | } |
174 | |
a20d9a3f |
175 | sub open { |
20f7b20c |
176 | ## |
177 | # Open a fh to the database, create if nonexistent. |
178 | # Make sure file signature matches DBM::Deep spec. |
179 | ## |
a20d9a3f |
180 | my $self = shift; |
70b55428 |
181 | my ($obj) = @_; |
a20d9a3f |
182 | |
673464d9 |
183 | # Theoretically, adding O_BINARY should remove the need for the binmode |
184 | # Of course, testing it is going to be ... interesting. |
185 | my $flags = O_RDWR | O_CREAT | O_BINARY; |
a20d9a3f |
186 | |
673464d9 |
187 | my $fh; |
d5d7c51d |
188 | my $filename = $obj->_root->{file}; |
189 | sysopen( $fh, $filename, $flags ) |
190 | or $obj->_throw_error("Cannot sysopen file '$filename': $!"); |
673464d9 |
191 | $obj->_root->{fh} = $fh; |
a20d9a3f |
192 | |
193 | #XXX Can we remove this by using the right sysopen() flags? |
194 | # Maybe ... q.v. above |
195 | binmode $fh; # for win32 |
196 | |
cd59cad8 |
197 | if ($obj->_root->{autoflush}) { |
a20d9a3f |
198 | my $old = select $fh; |
199 | $|=1; |
200 | select $old; |
201 | } |
20f7b20c |
202 | |
a20d9a3f |
203 | return 1; |
204 | } |
205 | |
3d1b8be9 |
206 | sub close_fh { |
cd59cad8 |
207 | my $self = shift; |
a21f2d90 |
208 | my ($obj) = @_; |
cd59cad8 |
209 | |
210 | if ( my $fh = $obj->_root->{fh} ) { |
211 | close $fh; |
212 | } |
213 | $obj->_root->{fh} = undef; |
214 | |
215 | return 1; |
216 | } |
217 | |
d4b1166e |
218 | sub create_tag { |
20f7b20c |
219 | ## |
220 | # Given offset, signature and content, create tag and write to disk |
221 | ## |
d4b1166e |
222 | my $self = shift; |
20f7b20c |
223 | my ($obj, $offset, $sig, $content) = @_; |
224 | my $size = length($content); |
225 | |
d4b1166e |
226 | my $fh = $obj->_fh; |
227 | |
20f7b20c |
228 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
251dfd0e |
229 | print( $fh $sig . pack($self->{data_pack}, $size) . $content ); |
20f7b20c |
230 | |
231 | if ($offset == $obj->_root->{end}) { |
8db25060 |
232 | $obj->_root->{end} += SIG_SIZE + $self->{data_size} + $size; |
20f7b20c |
233 | } |
234 | |
235 | return { |
236 | signature => $sig, |
237 | size => $size, |
8db25060 |
238 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
239 | content => $content |
240 | }; |
d4b1166e |
241 | } |
242 | |
243 | sub load_tag { |
20f7b20c |
244 | ## |
245 | # Given offset, load single tag and return signature, size and data |
246 | ## |
d4b1166e |
247 | my $self = shift; |
20f7b20c |
248 | my ($obj, $offset) = @_; |
249 | |
e06824f8 |
250 | # print join(':',map{$_||''}caller(1)), $/; |
251 | |
d4b1166e |
252 | my $fh = $obj->_fh; |
253 | |
20f7b20c |
254 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
e5fc7e69 |
255 | |
75be6413 |
256 | #XXX I'm not sure this check will work if autoflush isn't enabled ... |
e5fc7e69 |
257 | return if eof $fh; |
20f7b20c |
258 | |
d4b1166e |
259 | my $b; |
8db25060 |
260 | read( $fh, $b, SIG_SIZE + $self->{data_size} ); |
251dfd0e |
261 | my ($sig, $size) = unpack( "A $self->{data_pack}", $b ); |
20f7b20c |
262 | |
263 | my $buffer; |
264 | read( $fh, $buffer, $size); |
265 | |
266 | return { |
267 | signature => $sig, |
268 | size => $size, |
8db25060 |
269 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
270 | content => $buffer |
271 | }; |
d4b1166e |
272 | } |
273 | |
20f7b20c |
274 | sub add_bucket { |
275 | ## |
276 | # Adds one key/value pair to bucket list, given offset, MD5 digest of key, |
277 | # plain (undigested) key and value. |
278 | ## |
d4b1166e |
279 | my $self = shift; |
20f7b20c |
280 | my ($obj, $tag, $md5, $plain_key, $value) = @_; |
75be6413 |
281 | |
eea0d863 |
282 | # This verifies that only supported values will be stored. |
283 | { |
284 | my $r = Scalar::Util::reftype( $value ); |
285 | last if !defined $r; |
286 | |
287 | last if $r eq 'HASH'; |
288 | last if $r eq 'ARRAY'; |
289 | |
290 | $obj->_throw_error( |
291 | "Storage of variables of type '$r' is not supported." |
292 | ); |
293 | } |
294 | |
20f7b20c |
295 | my $location = 0; |
296 | my $result = 2; |
297 | |
298 | my $root = $obj->_root; |
299 | |
d5d7c51d |
300 | my $is_dbm_deep = eval { |
301 | local $SIG{'__DIE__'}; |
302 | $value->isa( 'DBM::Deep' ); |
303 | }; |
304 | |
20f7b20c |
305 | my $internal_ref = $is_dbm_deep && ($value->_root eq $root); |
306 | |
307 | my $fh = $obj->_fh; |
308 | |
386bab6c |
309 | my ($subloc, $offset) = $self->_find_in_buckets( $tag, $md5 ); |
75be6413 |
310 | |
386bab6c |
311 | # Updating a known md5 |
312 | if ( $subloc ) { |
313 | $result = 1; |
20f7b20c |
314 | |
386bab6c |
315 | ## |
d5d7c51d |
316 | # If value is a hash, array, or raw value with equal or less size, we |
317 | # can reuse the same content area of the database. Otherwise, we have |
318 | # to create a new content area at the EOF. |
386bab6c |
319 | ## |
320 | my $actual_length; |
321 | if ( $internal_ref ) { |
322 | $actual_length = $self->{long_size}; |
323 | } |
324 | else { |
325 | my $r = Scalar::Util::reftype( $value ) || ''; |
326 | if ( $r eq 'HASH' || $r eq 'ARRAY' ) { |
327 | $actual_length = $self->{index_size}; |
328 | |
329 | # if autobless is enabled, must also take into consideration |
330 | # the class name, as it is stored along with key/value. |
331 | if ( $root->{autobless} ) { |
332 | my $value_class = Scalar::Util::blessed($value); |
333 | if ( defined $value_class && !$value->isa('DBM::Deep') ) { |
334 | $actual_length += length($value_class); |
8db25060 |
335 | } |
75be6413 |
336 | } |
20f7b20c |
337 | } |
386bab6c |
338 | else { $actual_length = length($value); } |
75be6413 |
339 | } |
20f7b20c |
340 | |
d5d7c51d |
341 | seek($fh, $subloc + SIG_SIZE + $root->{file_offset}, SEEK_SET); |
342 | my $size; |
343 | read( $fh, $size, $self->{data_size}); |
344 | $size = unpack($self->{data_pack}, $size); |
345 | |
386bab6c |
346 | if ($actual_length <= $size) { |
347 | $location = $subloc; |
20f7b20c |
348 | } |
75be6413 |
349 | else { |
350 | $location = $root->{end}; |
386bab6c |
351 | seek( |
352 | $fh, |
353 | $tag->{offset} + $offset + $self->{hash_size} + $root->{file_offset}, |
354 | SEEK_SET, |
355 | ); |
356 | print( $fh pack($self->{long_pack}, $location) ); |
75be6413 |
357 | } |
75be6413 |
358 | } |
386bab6c |
359 | # Adding a new md5 |
360 | elsif ( defined $offset ) { |
386bab6c |
361 | $location = $root->{end}; |
362 | |
363 | seek( $fh, $tag->{offset} + $offset + $root->{file_offset}, SEEK_SET ); |
364 | print( $fh $md5 . pack($self->{long_pack}, $location) ); |
365 | } |
366 | # If bucket didn't fit into list, split into a new index level |
367 | else { |
368 | $self->split_index( $obj, $md5, $tag ); |
369 | |
370 | $location = $root->{end}; |
371 | } |
20f7b20c |
372 | |
d5d7c51d |
373 | $self->write_value( $obj, $location, $plain_key, $value ); |
374 | |
375 | return $result; |
376 | } |
377 | |
378 | sub write_value { |
379 | my $self = shift; |
380 | my ($obj, $location, $key, $value) = @_; |
381 | |
382 | my $fh = $obj->_fh; |
383 | my $root = $obj->_root; |
384 | |
385 | my $is_dbm_deep = eval { |
386 | local $SIG{'__DIE__'}; |
387 | $value->isa( 'DBM::Deep' ); |
388 | }; |
389 | |
390 | my $internal_ref = $is_dbm_deep && ($value->_root eq $root); |
391 | |
392 | seek($fh, $location + $root->{file_offset}, SEEK_SET); |
393 | |
20f7b20c |
394 | ## |
d5d7c51d |
395 | # Write signature based on content type, set content length and write |
396 | # actual value. |
20f7b20c |
397 | ## |
d5d7c51d |
398 | my $r = Scalar::Util::reftype($value) || ''; |
399 | my $content_length; |
400 | if ( $internal_ref ) { |
401 | print( $fh SIG_INTERNAL ); |
402 | print( $fh pack($self->{data_pack}, $self->{long_size}) ); |
403 | print( $fh pack($self->{long_pack}, $value->_base_offset) ); |
404 | $content_length = $self->{long_size}; |
405 | } |
406 | else { |
407 | if ($r eq 'HASH') { |
408 | print( $fh SIG_HASH ); |
409 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
410 | $content_length = $self->{index_size}; |
411 | } |
412 | elsif ($r eq 'ARRAY') { |
413 | print( $fh SIG_ARRAY ); |
414 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
415 | $content_length = $self->{index_size}; |
416 | } |
417 | elsif (!defined($value)) { |
418 | print( $fh SIG_NULL ); |
419 | print( $fh pack($self->{data_pack}, 0) ); |
420 | $content_length = 0; |
20f7b20c |
421 | } |
422 | else { |
d5d7c51d |
423 | print( $fh SIG_DATA ); |
424 | print( $fh pack($self->{data_pack}, length($value)) . $value ); |
425 | $content_length = length($value); |
20f7b20c |
426 | } |
d5d7c51d |
427 | } |
20f7b20c |
428 | |
d5d7c51d |
429 | ## |
430 | # Plain key is stored AFTER value, as keys are typically fetched less often. |
431 | ## |
432 | print( $fh pack($self->{data_pack}, length($key)) . $key ); |
20f7b20c |
433 | |
d5d7c51d |
434 | ## |
435 | # If value is blessed, preserve class name |
436 | ## |
437 | if ( $root->{autobless} ) { |
438 | my $value_class = Scalar::Util::blessed($value); |
439 | if ( defined $value_class && !$value->isa( 'DBM::Deep' ) ) { |
440 | ## |
441 | # Blessed ref -- will restore later |
442 | ## |
443 | print( $fh chr(1) ); |
444 | print( $fh pack($self->{data_pack}, length($value_class)) . $value_class ); |
445 | $content_length += 1; |
446 | $content_length += $self->{data_size} + length($value_class); |
20f7b20c |
447 | } |
d5d7c51d |
448 | else { |
449 | print( $fh chr(0) ); |
450 | $content_length += 1; |
20f7b20c |
451 | } |
d5d7c51d |
452 | } |
20f7b20c |
453 | |
d5d7c51d |
454 | ## |
455 | # If this is a new content area, advance EOF counter |
456 | ## |
457 | if ($location == $root->{end}) { |
458 | $root->{end} += SIG_SIZE; |
459 | $root->{end} += $self->{data_size} + $content_length; |
460 | $root->{end} += $self->{data_size} + length($key); |
461 | } |
462 | |
463 | ## |
464 | # If content is a hash or array, create new child DBM::Deep object and |
465 | # pass each key or element to it. |
466 | ## |
467 | if ( ! $internal_ref ) { |
468 | if ($r eq 'HASH') { |
469 | my $branch = DBM::Deep->new( |
470 | type => DBM::Deep->TYPE_HASH, |
471 | base_offset => $location, |
472 | root => $root, |
473 | ); |
474 | foreach my $key (keys %{$value}) { |
475 | $branch->STORE( $key, $value->{$key} ); |
20f7b20c |
476 | } |
d5d7c51d |
477 | } |
478 | elsif ($r eq 'ARRAY') { |
479 | my $branch = DBM::Deep->new( |
480 | type => DBM::Deep->TYPE_ARRAY, |
481 | base_offset => $location, |
482 | root => $root, |
483 | ); |
484 | my $index = 0; |
485 | foreach my $element (@{$value}) { |
486 | $branch->STORE( $index, $element ); |
487 | $index++; |
20f7b20c |
488 | } |
489 | } |
20f7b20c |
490 | } |
d4b1166e |
491 | |
d5d7c51d |
492 | return 1; |
d4b1166e |
493 | } |
494 | |
75be6413 |
495 | sub split_index { |
496 | my $self = shift; |
497 | my ($obj, $md5, $tag) = @_; |
498 | |
499 | my $fh = $obj->_fh; |
500 | my $root = $obj->_root; |
501 | my $keys = $tag->{content}; |
502 | |
503 | seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET); |
504 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
505 | |
506 | my $index_tag = $self->create_tag( |
507 | $obj, |
508 | $root->{end}, |
8db25060 |
509 | SIG_INDEX, |
75be6413 |
510 | chr(0) x $self->{index_size}, |
511 | ); |
512 | |
513 | my @offsets = (); |
514 | |
515 | $keys .= $md5 . pack($self->{long_pack}, 0); |
516 | |
517 | BUCKET: |
518 | for (my $i = 0; $i <= $self->{max_buckets}; $i++) { |
9cec1360 |
519 | my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i ); |
75be6413 |
520 | |
521 | next BUCKET unless $key; |
522 | |
75be6413 |
523 | my $num = ord(substr($key, $tag->{ch} + 1, 1)); |
524 | |
525 | if ($offsets[$num]) { |
8db25060 |
526 | my $offset = $offsets[$num] + SIG_SIZE + $self->{data_size}; |
75be6413 |
527 | seek($fh, $offset + $root->{file_offset}, SEEK_SET); |
528 | my $subkeys; |
529 | read( $fh, $subkeys, $self->{bucket_list_size}); |
530 | |
531 | for (my $k=0; $k<$self->{max_buckets}; $k++) { |
9cec1360 |
532 | my ($temp, $subloc) = $self->_get_key_subloc( $subkeys, $k ); |
75be6413 |
533 | |
534 | if (!$subloc) { |
535 | seek($fh, $offset + ($k * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
536 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
537 | last; |
538 | } |
539 | } # k loop |
540 | } |
541 | else { |
542 | $offsets[$num] = $root->{end}; |
543 | seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET); |
544 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
545 | |
8db25060 |
546 | my $blist_tag = $self->create_tag($obj, $root->{end}, SIG_BLIST, chr(0) x $self->{bucket_list_size}); |
75be6413 |
547 | |
548 | seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET); |
549 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
550 | } |
551 | } # i loop |
552 | |
553 | return; |
554 | } |
555 | |
8db25060 |
556 | sub read_from_loc { |
557 | my $self = shift; |
558 | my ($obj, $subloc) = @_; |
559 | |
560 | my $fh = $obj->_fh; |
561 | |
562 | ## |
563 | # Found match -- seek to offset and read signature |
564 | ## |
565 | my $signature; |
566 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
567 | read( $fh, $signature, SIG_SIZE); |
568 | |
569 | ## |
570 | # If value is a hash or array, return new DBM::Deep object with correct offset |
571 | ## |
572 | if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) { |
573 | my $obj = DBM::Deep->new( |
574 | type => $signature, |
575 | base_offset => $subloc, |
576 | root => $obj->_root, |
577 | ); |
578 | |
579 | if ($obj->_root->{autobless}) { |
580 | ## |
581 | # Skip over value and plain key to see if object needs |
582 | # to be re-blessed |
583 | ## |
584 | seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR); |
585 | |
586 | my $size; |
587 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
588 | if ($size) { seek($fh, $size, SEEK_CUR); } |
589 | |
590 | my $bless_bit; |
591 | read( $fh, $bless_bit, 1); |
592 | if (ord($bless_bit)) { |
593 | ## |
594 | # Yes, object needs to be re-blessed |
595 | ## |
596 | my $class_name; |
597 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
598 | if ($size) { read( $fh, $class_name, $size); } |
599 | if ($class_name) { $obj = bless( $obj, $class_name ); } |
600 | } |
601 | } |
602 | |
603 | return $obj; |
604 | } |
605 | elsif ( $signature eq SIG_INTERNAL ) { |
606 | my $size; |
607 | read( $fh, $size, $self->{data_size}); |
608 | $size = unpack($self->{data_pack}, $size); |
609 | |
610 | if ( $size ) { |
611 | my $new_loc; |
612 | read( $fh, $new_loc, $size ); |
613 | $new_loc = unpack( $self->{long_pack}, $new_loc ); |
614 | |
615 | return $self->read_from_loc( $obj, $new_loc ); |
616 | } |
617 | else { |
618 | return; |
619 | } |
620 | } |
621 | ## |
622 | # Otherwise return actual value |
623 | ## |
624 | elsif ($signature eq SIG_DATA) { |
625 | my $size; |
626 | read( $fh, $size, $self->{data_size}); |
627 | $size = unpack($self->{data_pack}, $size); |
628 | |
629 | my $value = ''; |
630 | if ($size) { read( $fh, $value, $size); } |
631 | return $value; |
632 | } |
633 | |
634 | ## |
635 | # Key exists, but content is null |
636 | ## |
637 | return; |
638 | } |
639 | |
9020ee8c |
640 | sub get_bucket_value { |
beac1dff |
641 | ## |
642 | # Fetch single value given tag and MD5 digested key. |
643 | ## |
644 | my $self = shift; |
645 | my ($obj, $tag, $md5) = @_; |
9020ee8c |
646 | |
386bab6c |
647 | my ($subloc, $offset) = $self->_find_in_buckets( $tag, $md5 ); |
648 | if ( $subloc ) { |
8db25060 |
649 | return $self->read_from_loc( $obj, $subloc ); |
386bab6c |
650 | } |
beac1dff |
651 | return; |
9020ee8c |
652 | } |
ab0e4957 |
653 | |
654 | sub delete_bucket { |
beac1dff |
655 | ## |
656 | # Delete single key/value pair given tag and MD5 digested key. |
657 | ## |
658 | my $self = shift; |
659 | my ($obj, $tag, $md5) = @_; |
ab0e4957 |
660 | |
386bab6c |
661 | my ($subloc, $offset) = $self->_find_in_buckets( $tag, $md5 ); |
662 | if ( $subloc ) { |
663 | my $fh = $obj->_fh; |
664 | seek($fh, $tag->{offset} + $offset + $obj->_root->{file_offset}, SEEK_SET); |
665 | print( $fh substr($tag->{content}, $offset + $self->{bucket_size} ) ); |
251dfd0e |
666 | print( $fh chr(0) x $self->{bucket_size} ); |
d0b74c17 |
667 | |
ab0e4957 |
668 | return 1; |
386bab6c |
669 | } |
beac1dff |
670 | return; |
ab0e4957 |
671 | } |
672 | |
912d50b1 |
673 | sub bucket_exists { |
beac1dff |
674 | ## |
675 | # Check existence of single key given tag and MD5 digested key. |
676 | ## |
677 | my $self = shift; |
678 | my ($obj, $tag, $md5) = @_; |
912d50b1 |
679 | |
386bab6c |
680 | my ($subloc, $offset) = $self->_find_in_buckets( $tag, $md5 ); |
d5d7c51d |
681 | return $subloc && 1; |
912d50b1 |
682 | } |
683 | |
6736c116 |
684 | sub find_bucket_list { |
beac1dff |
685 | ## |
686 | # Locate offset for bucket list, given digested key |
687 | ## |
688 | my $self = shift; |
d0b74c17 |
689 | my ($obj, $md5, $args) = @_; |
690 | $args = {} unless $args; |
691 | |
beac1dff |
692 | ## |
693 | # Locate offset for bucket list using digest index system |
694 | ## |
e5fc7e69 |
695 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
d5d7c51d |
696 | or $obj->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
d0b74c17 |
697 | |
e5fc7e69 |
698 | my $ch = 0; |
8db25060 |
699 | while ($tag->{signature} ne SIG_BLIST) { |
d0b74c17 |
700 | my $num = ord substr($md5, $ch, 1); |
701 | |
702 | my $ref_loc = $tag->{offset} + ($num * $self->{long_size}); |
703 | $tag = $self->index_lookup( $obj, $tag, $num ); |
704 | |
705 | if (!$tag) { |
d5d7c51d |
706 | return if ! $args->{create}; |
d0b74c17 |
707 | |
d5d7c51d |
708 | my $fh = $obj->_fh; |
709 | seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET); |
710 | print( $fh pack($self->{long_pack}, $obj->_root->{end}) ); |
d0b74c17 |
711 | |
d5d7c51d |
712 | $tag = $self->create_tag( |
713 | $obj, $obj->_root->{end}, |
714 | SIG_BLIST, |
715 | chr(0) x $self->{bucket_list_size}, |
716 | ); |
717 | |
718 | $tag->{ref_loc} = $ref_loc; |
719 | $tag->{ch} = $ch; |
720 | |
721 | last; |
d0b74c17 |
722 | } |
723 | |
724 | $tag->{ch} = $ch; |
725 | $tag->{ref_loc} = $ref_loc; |
726 | |
beac1dff |
727 | $ch++; |
728 | } |
d0b74c17 |
729 | |
beac1dff |
730 | return $tag; |
6736c116 |
731 | } |
732 | |
d0b74c17 |
733 | sub index_lookup { |
734 | ## |
735 | # Given index tag, lookup single entry in index and return . |
736 | ## |
737 | my $self = shift; |
738 | my ($obj, $tag, $index) = @_; |
739 | |
740 | my $location = unpack( |
741 | $self->{long_pack}, |
742 | substr( |
743 | $tag->{content}, |
744 | $index * $self->{long_size}, |
745 | $self->{long_size}, |
746 | ), |
747 | ); |
748 | |
749 | if (!$location) { return; } |
750 | |
751 | return $self->load_tag( $obj, $location ); |
752 | } |
753 | |
6736c116 |
754 | sub traverse_index { |
beac1dff |
755 | ## |
756 | # Scan index and recursively step into deeper levels, looking for next key. |
757 | ## |
6736c116 |
758 | my $self = shift; |
759 | my ($obj, $offset, $ch, $force_return_next) = @_; |
d0b74c17 |
760 | |
beac1dff |
761 | my $tag = $self->load_tag($obj, $offset ); |
6736c116 |
762 | |
763 | my $fh = $obj->_fh; |
d0b74c17 |
764 | |
8db25060 |
765 | if ($tag->{signature} ne SIG_BLIST) { |
beac1dff |
766 | my $content = $tag->{content}; |
e5fc7e69 |
767 | my $start = $obj->{return_next} ? 0 : ord(substr($obj->{prev_md5}, $ch, 1)); |
d0b74c17 |
768 | |
d5d7c51d |
769 | for (my $idx = $start; $idx < (2**8); $idx++) { |
e5fc7e69 |
770 | my $subloc = unpack( |
771 | $self->{long_pack}, |
e06824f8 |
772 | substr( |
773 | $content, |
774 | $idx * $self->{long_size}, |
775 | $self->{long_size}, |
776 | ), |
e5fc7e69 |
777 | ); |
778 | |
beac1dff |
779 | if ($subloc) { |
e5fc7e69 |
780 | my $result = $self->traverse_index( |
781 | $obj, $subloc, $ch + 1, $force_return_next, |
782 | ); |
783 | |
beac1dff |
784 | if (defined($result)) { return $result; } |
785 | } |
786 | } # index loop |
d0b74c17 |
787 | |
beac1dff |
788 | $obj->{return_next} = 1; |
789 | } # tag is an index |
d0b74c17 |
790 | |
e5fc7e69 |
791 | else { |
beac1dff |
792 | my $keys = $tag->{content}; |
793 | if ($force_return_next) { $obj->{return_next} = 1; } |
d0b74c17 |
794 | |
beac1dff |
795 | ## |
796 | # Iterate through buckets, looking for a key match |
797 | ## |
8db25060 |
798 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
9cec1360 |
799 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
d0b74c17 |
800 | |
8db25060 |
801 | # End of bucket list -- return to outer loop |
beac1dff |
802 | if (!$subloc) { |
beac1dff |
803 | $obj->{return_next} = 1; |
804 | last; |
805 | } |
8db25060 |
806 | # Located previous key -- return next one found |
beac1dff |
807 | elsif ($key eq $obj->{prev_md5}) { |
beac1dff |
808 | $obj->{return_next} = 1; |
809 | next; |
810 | } |
8db25060 |
811 | # Seek to bucket location and skip over signature |
beac1dff |
812 | elsif ($obj->{return_next}) { |
8db25060 |
813 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
d0b74c17 |
814 | |
beac1dff |
815 | # Skip over value to get to plain key |
8db25060 |
816 | my $sig; |
817 | read( $fh, $sig, SIG_SIZE ); |
818 | |
beac1dff |
819 | my $size; |
e5fc7e69 |
820 | read( $fh, $size, $self->{data_size}); |
821 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
822 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
823 | |
beac1dff |
824 | # Read in plain key and return as scalar |
beac1dff |
825 | my $plain_key; |
e5fc7e69 |
826 | read( $fh, $size, $self->{data_size}); |
827 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
828 | if ($size) { read( $fh, $plain_key, $size); } |
d0b74c17 |
829 | |
beac1dff |
830 | return $plain_key; |
831 | } |
8db25060 |
832 | } |
d0b74c17 |
833 | |
beac1dff |
834 | $obj->{return_next} = 1; |
835 | } # tag is a bucket list |
d0b74c17 |
836 | |
beac1dff |
837 | return; |
6736c116 |
838 | } |
839 | |
840 | sub get_next_key { |
beac1dff |
841 | ## |
842 | # Locate next key, given digested previous one |
843 | ## |
6736c116 |
844 | my $self = shift; |
845 | my ($obj) = @_; |
d0b74c17 |
846 | |
beac1dff |
847 | $obj->{prev_md5} = $_[1] ? $_[1] : undef; |
848 | $obj->{return_next} = 0; |
d0b74c17 |
849 | |
beac1dff |
850 | ## |
851 | # If the previous key was not specifed, start at the top and |
852 | # return the first one found. |
853 | ## |
854 | if (!$obj->{prev_md5}) { |
855 | $obj->{prev_md5} = chr(0) x $self->{hash_size}; |
856 | $obj->{return_next} = 1; |
857 | } |
d0b74c17 |
858 | |
beac1dff |
859 | return $self->traverse_index( $obj, $obj->_base_offset, 0 ); |
6736c116 |
860 | } |
861 | |
75be6413 |
862 | # Utilities |
863 | |
9cec1360 |
864 | sub _get_key_subloc { |
75be6413 |
865 | my $self = shift; |
866 | my ($keys, $idx) = @_; |
867 | |
9cec1360 |
868 | my ($key, $subloc) = unpack( |
869 | "a$self->{hash_size} $self->{long_pack}", |
75be6413 |
870 | substr( |
871 | $keys, |
9cec1360 |
872 | ($idx * $self->{bucket_size}), |
873 | $self->{bucket_size}, |
75be6413 |
874 | ), |
875 | ); |
876 | |
9cec1360 |
877 | return ($key, $subloc); |
75be6413 |
878 | } |
879 | |
d608b06e |
880 | sub _find_in_buckets { |
881 | my $self = shift; |
882 | my ($tag, $md5) = @_; |
883 | |
884 | BUCKET: |
885 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
886 | my ($key, $subloc) = $self->_get_key_subloc( $tag->{content}, $i ); |
887 | |
888 | return ($subloc, $i * $self->{bucket_size}) unless $subloc; |
889 | |
890 | next BUCKET if $key ne $md5; |
891 | |
892 | return ($subloc, $i * $self->{bucket_size}); |
893 | } |
894 | |
895 | return; |
896 | } |
897 | |
994ccd8e |
898 | sub _request_space { |
899 | my $self = shift; |
900 | my ($obj, $size) = @_; |
901 | |
902 | my $loc = $obj->_root->{end}; |
c9ec091a |
903 | $obj->_root->{end} += $size; |
994ccd8e |
904 | |
905 | return $loc; |
906 | } |
907 | |
908 | sub _release_space { |
909 | my $self = shift; |
910 | my ($obj, $size, $loc) = @_; |
911 | |
912 | return; |
913 | } |
914 | |
a20d9a3f |
915 | 1; |
916 | __END__ |
d5d7c51d |
917 | |
918 | # This will be added in later, after more refactoring is done. This is an early |
919 | # attempt at refactoring on the physical level instead of the virtual level. |
920 | sub _read_at { |
921 | my $self = shift; |
922 | my ($obj, $spot, $amount, $unpack) = @_; |
923 | |
924 | my $fh = $obj->_fh; |
925 | seek( $fh, $spot + $obj->_root->{file_offset}, SEEK_SET ); |
926 | |
927 | my $buffer; |
928 | my $bytes_read = read( $fh, $buffer, $amount ); |
929 | |
930 | if ( $unpack ) { |
931 | $buffer = unpack( $unpack, $buffer ); |
932 | } |
933 | |
934 | if ( wantarray ) { |
935 | return ($buffer, $bytes_read); |
936 | } |
937 | else { |
938 | return $buffer; |
939 | } |
940 | } |