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