Commit | Line | Data |
a20d9a3f |
1 | package DBM::Deep::Engine; |
2 | |
3 | use strict; |
4 | |
5 | use Fcntl qw( :DEFAULT :flock :seek ); |
6 | |
612969fb |
7 | sub precalc_sizes { |
beac1dff |
8 | ## |
9 | # Precalculate index, bucket and bucket list sizes |
10 | ## |
251dfd0e |
11 | my $self = shift; |
1bf65be7 |
12 | |
251dfd0e |
13 | $self->{index_size} = (2**8) * $self->{long_size}; |
14 | $self->{bucket_size} = $self->{hash_size} + $self->{long_size}; |
15 | $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size}; |
1bf65be7 |
16 | |
251dfd0e |
17 | return 1; |
1bf65be7 |
18 | } |
19 | |
20 | sub set_pack { |
beac1dff |
21 | ## |
22 | # Set pack/unpack modes (see file header for more) |
23 | ## |
251dfd0e |
24 | my $self = shift; |
1bf65be7 |
25 | my ($long_s, $long_p, $data_s, $data_p) = @_; |
26 | |
81d16922 |
27 | ## |
28 | # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4 GB per file. |
beac1dff |
29 | # (Perl must be compiled with largefile support for files > 2 GB) |
81d16922 |
30 | # |
31 | # Set to 8 and 'Q' for 64-bit offsets. Theoretical limit of 16 XB per file. |
beac1dff |
32 | # (Perl must be compiled with largefile and 64-bit long support) |
81d16922 |
33 | ## |
251dfd0e |
34 | $self->{long_size} = $long_s ? $long_s : 4; |
35 | $self->{long_pack} = $long_p ? $long_p : 'N'; |
1bf65be7 |
36 | |
81d16922 |
37 | ## |
38 | # Set to 4 and 'N' for 32-bit data length prefixes. Limit of 4 GB for each key/value. |
39 | # Upgrading this is possible (see above) but probably not necessary. If you need |
40 | # more than 4 GB for a single key or value, this module is really not for you :-) |
41 | ## |
251dfd0e |
42 | $self->{data_size} = $data_s ? $data_s : 4; |
43 | $self->{data_pack} = $data_p ? $data_p : 'N'; |
1bf65be7 |
44 | |
beac1dff |
45 | return $self->precalc_sizes(); |
1bf65be7 |
46 | } |
47 | |
48 | sub set_digest { |
beac1dff |
49 | ## |
50 | # Set key digest function (default is MD5) |
51 | ## |
251dfd0e |
52 | my $self = shift; |
1bf65be7 |
53 | my ($digest_func, $hash_size) = @_; |
54 | |
d0b74c17 |
55 | $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5; |
251dfd0e |
56 | $self->{hash_size} = $hash_size ? $hash_size : 16; |
612969fb |
57 | |
beac1dff |
58 | return $self->precalc_sizes(); |
612969fb |
59 | } |
60 | |
61 | sub new { |
62 | my $class = shift; |
63 | my ($args) = @_; |
64 | |
65 | my $self = bless { |
66 | long_size => 4, |
67 | long_pack => 'N', |
68 | data_size => 4, |
69 | data_pack => 'N', |
251dfd0e |
70 | |
612969fb |
71 | digest => \&Digest::MD5::md5, |
72 | hash_size => 16, |
251dfd0e |
73 | |
81d16922 |
74 | ## |
75 | # Maximum number of buckets per list before another level of indexing is done. |
76 | # Increase this value for slightly greater speed, but larger database files. |
77 | # DO NOT decrease this value below 16, due to risk of recursive reindex overrun. |
78 | ## |
612969fb |
79 | max_buckets => 16, |
80 | }, $class; |
81 | |
251dfd0e |
82 | $self->precalc_sizes; |
612969fb |
83 | |
84 | return $self; |
1bf65be7 |
85 | } |
86 | |
70b55428 |
87 | sub setup_fh { |
88 | my $self = shift; |
89 | my ($obj) = @_; |
90 | |
91 | $self->open( $obj ) if !defined $obj->_fh; |
92 | |
673464d9 |
93 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
70b55428 |
94 | unless ( $obj->_root->{inode} ) { |
95 | my @stats = stat($obj->_fh); |
96 | $obj->_root->{inode} = $stats[1]; |
97 | $obj->_root->{end} = $stats[7]; |
98 | } |
99 | |
100 | return 1; |
101 | } |
102 | |
a20d9a3f |
103 | sub open { |
20f7b20c |
104 | ## |
105 | # Open a fh to the database, create if nonexistent. |
106 | # Make sure file signature matches DBM::Deep spec. |
107 | ## |
a20d9a3f |
108 | my $self = shift; |
70b55428 |
109 | my ($obj) = @_; |
a20d9a3f |
110 | |
3d1b8be9 |
111 | if (defined($obj->_fh)) { $self->close_fh( $obj ); } |
20f7b20c |
112 | |
673464d9 |
113 | # Theoretically, adding O_BINARY should remove the need for the binmode |
114 | # Of course, testing it is going to be ... interesting. |
115 | my $flags = O_RDWR | O_CREAT | O_BINARY; |
a20d9a3f |
116 | |
673464d9 |
117 | my $fh; |
118 | sysopen( $fh, $obj->_root->{file}, $flags ) |
119 | or $obj->_throw_error("Cannot sysopen file: " . $obj->_root->{file} . ": $!"); |
120 | $obj->_root->{fh} = $fh; |
a20d9a3f |
121 | |
122 | #XXX Can we remove this by using the right sysopen() flags? |
123 | # Maybe ... q.v. above |
124 | binmode $fh; # for win32 |
125 | |
cd59cad8 |
126 | if ($obj->_root->{autoflush}) { |
a20d9a3f |
127 | my $old = select $fh; |
128 | $|=1; |
129 | select $old; |
130 | } |
20f7b20c |
131 | |
cd59cad8 |
132 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
a20d9a3f |
133 | |
134 | my $signature; |
135 | my $bytes_read = read( $fh, $signature, length(DBM::Deep->SIG_FILE)); |
20f7b20c |
136 | |
a20d9a3f |
137 | ## |
138 | # File is empty -- write signature and master index |
139 | ## |
140 | if (!$bytes_read) { |
cd59cad8 |
141 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
a20d9a3f |
142 | print( $fh DBM::Deep->SIG_FILE); |
d0b74c17 |
143 | |
ec1bce6b |
144 | $self->create_tag($obj, $obj->_base_offset, $obj->_type, chr(0) x $self->{index_size}); |
a20d9a3f |
145 | |
146 | my $plain_key = "[base]"; |
251dfd0e |
147 | print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key ); |
a20d9a3f |
148 | |
149 | # Flush the filehandle |
150 | my $old_fh = select $fh; |
151 | my $old_af = $|; $| = 1; $| = $old_af; |
152 | select $old_fh; |
153 | |
a20d9a3f |
154 | return 1; |
155 | } |
20f7b20c |
156 | |
a20d9a3f |
157 | ## |
158 | # Check signature was valid |
159 | ## |
160 | unless ($signature eq DBM::Deep->SIG_FILE) { |
3d1b8be9 |
161 | $self->close_fh( $obj ); |
cd59cad8 |
162 | return $obj->_throw_error("Signature not found -- file is not a Deep DB"); |
a20d9a3f |
163 | } |
164 | |
a20d9a3f |
165 | ## |
166 | # Get our type from master index signature |
167 | ## |
d4b1166e |
168 | my $tag = $self->load_tag($obj, $obj->_base_offset); |
a20d9a3f |
169 | if (!$tag) { |
20f7b20c |
170 | return $obj->_throw_error("Corrupted file, no master index record"); |
a20d9a3f |
171 | } |
d0b74c17 |
172 | |
cd59cad8 |
173 | if ($obj->{type} ne $tag->{signature}) { |
20f7b20c |
174 | return $obj->_throw_error("File type mismatch"); |
a20d9a3f |
175 | } |
20f7b20c |
176 | |
d0b74c17 |
177 | #XXX We probably also want to store the hash algorithm name and not assume anything |
178 | #XXX The cool thing would be to allow a different hashing algorithm at every level |
179 | |
a20d9a3f |
180 | return 1; |
181 | } |
182 | |
3d1b8be9 |
183 | sub close_fh { |
cd59cad8 |
184 | my $self = shift; |
a21f2d90 |
185 | my ($obj) = @_; |
cd59cad8 |
186 | |
187 | if ( my $fh = $obj->_root->{fh} ) { |
188 | close $fh; |
189 | } |
190 | $obj->_root->{fh} = undef; |
191 | |
192 | return 1; |
193 | } |
194 | |
d4b1166e |
195 | sub create_tag { |
20f7b20c |
196 | ## |
197 | # Given offset, signature and content, create tag and write to disk |
198 | ## |
d4b1166e |
199 | my $self = shift; |
20f7b20c |
200 | my ($obj, $offset, $sig, $content) = @_; |
201 | my $size = length($content); |
202 | |
d4b1166e |
203 | my $fh = $obj->_fh; |
204 | |
20f7b20c |
205 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
251dfd0e |
206 | print( $fh $sig . pack($self->{data_pack}, $size) . $content ); |
20f7b20c |
207 | |
208 | if ($offset == $obj->_root->{end}) { |
251dfd0e |
209 | $obj->_root->{end} += DBM::Deep->SIG_SIZE + $self->{data_size} + $size; |
20f7b20c |
210 | } |
211 | |
212 | return { |
213 | signature => $sig, |
214 | size => $size, |
251dfd0e |
215 | offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size}, |
20f7b20c |
216 | content => $content |
217 | }; |
d4b1166e |
218 | } |
219 | |
220 | sub load_tag { |
20f7b20c |
221 | ## |
222 | # Given offset, load single tag and return signature, size and data |
223 | ## |
d4b1166e |
224 | my $self = shift; |
20f7b20c |
225 | my ($obj, $offset) = @_; |
226 | |
d4b1166e |
227 | my $fh = $obj->_fh; |
228 | |
20f7b20c |
229 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
230 | if (eof $fh) { return undef; } |
231 | |
d4b1166e |
232 | my $b; |
251dfd0e |
233 | read( $fh, $b, DBM::Deep->SIG_SIZE + $self->{data_size} ); |
234 | my ($sig, $size) = unpack( "A $self->{data_pack}", $b ); |
20f7b20c |
235 | |
236 | my $buffer; |
237 | read( $fh, $buffer, $size); |
238 | |
239 | return { |
240 | signature => $sig, |
241 | size => $size, |
251dfd0e |
242 | offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size}, |
20f7b20c |
243 | content => $buffer |
244 | }; |
d4b1166e |
245 | } |
246 | |
20f7b20c |
247 | sub add_bucket { |
248 | ## |
249 | # Adds one key/value pair to bucket list, given offset, MD5 digest of key, |
250 | # plain (undigested) key and value. |
251 | ## |
d4b1166e |
252 | my $self = shift; |
20f7b20c |
253 | my ($obj, $tag, $md5, $plain_key, $value) = @_; |
254 | my $keys = $tag->{content}; |
255 | my $location = 0; |
256 | my $result = 2; |
257 | |
258 | my $root = $obj->_root; |
259 | |
260 | my $is_dbm_deep = eval { local $SIG{'__DIE__'}; $value->isa( 'DBM::Deep' ) }; |
261 | my $internal_ref = $is_dbm_deep && ($value->_root eq $root); |
262 | |
263 | my $fh = $obj->_fh; |
264 | |
265 | ## |
266 | # Iterate through buckets, seeing if this is a new entry or a replace. |
267 | ## |
d0b74c17 |
268 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
251dfd0e |
269 | my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size})); |
20f7b20c |
270 | if (!$subloc) { |
271 | ## |
272 | # Found empty bucket (end of list). Populate and exit loop. |
273 | ## |
274 | $result = 2; |
275 | |
276 | $location = $internal_ref |
277 | ? $value->_base_offset |
278 | : $root->{end}; |
279 | |
251dfd0e |
280 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
281 | print( $fh $md5 . pack($self->{long_pack}, $location) ); |
20f7b20c |
282 | last; |
283 | } |
284 | |
251dfd0e |
285 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
20f7b20c |
286 | if ($md5 eq $key) { |
287 | ## |
288 | # Found existing bucket with same key. Replace with new value. |
289 | ## |
290 | $result = 1; |
291 | |
292 | if ($internal_ref) { |
293 | $location = $value->_base_offset; |
251dfd0e |
294 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
295 | print( $fh $md5 . pack($self->{long_pack}, $location) ); |
20f7b20c |
296 | return $result; |
297 | } |
298 | |
299 | seek($fh, $subloc + DBM::Deep->SIG_SIZE + $root->{file_offset}, SEEK_SET); |
300 | my $size; |
251dfd0e |
301 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
20f7b20c |
302 | |
303 | ## |
304 | # If value is a hash, array, or raw value with equal or less size, we can |
305 | # reuse the same content area of the database. Otherwise, we have to create |
306 | # a new content area at the EOF. |
307 | ## |
308 | my $actual_length; |
309 | my $r = Scalar::Util::reftype( $value ) || ''; |
310 | if ( $r eq 'HASH' || $r eq 'ARRAY' ) { |
ec1bce6b |
311 | $actual_length = $self->{index_size}; |
20f7b20c |
312 | |
313 | # if autobless is enabled, must also take into consideration |
314 | # the class name, as it is stored along with key/value. |
315 | if ( $root->{autobless} ) { |
316 | my $value_class = Scalar::Util::blessed($value); |
317 | if ( defined $value_class && !$value->isa('DBM::Deep') ) { |
318 | $actual_length += length($value_class); |
319 | } |
320 | } |
321 | } |
322 | else { $actual_length = length($value); } |
323 | |
324 | if ($actual_length <= $size) { |
325 | $location = $subloc; |
326 | } |
327 | else { |
328 | $location = $root->{end}; |
251dfd0e |
329 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $self->{hash_size} + $root->{file_offset}, SEEK_SET); |
330 | print( $fh pack($self->{long_pack}, $location) ); |
20f7b20c |
331 | } |
332 | |
333 | last; |
334 | } |
335 | } |
336 | |
337 | ## |
338 | # If this is an internal reference, return now. |
339 | # No need to write value or plain key |
340 | ## |
341 | if ($internal_ref) { |
342 | return $result; |
343 | } |
344 | |
345 | ## |
346 | # If bucket didn't fit into list, split into a new index level |
347 | ## |
348 | if (!$location) { |
349 | seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET); |
251dfd0e |
350 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
20f7b20c |
351 | |
ec1bce6b |
352 | my $index_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_INDEX, chr(0) x $self->{index_size}); |
20f7b20c |
353 | my @offsets = (); |
354 | |
251dfd0e |
355 | $keys .= $md5 . pack($self->{long_pack}, 0); |
20f7b20c |
356 | |
251dfd0e |
357 | for (my $i=0; $i<=$self->{max_buckets}; $i++) { |
358 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
20f7b20c |
359 | if ($key) { |
251dfd0e |
360 | my $old_subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + |
361 | $self->{hash_size}, $self->{long_size})); |
20f7b20c |
362 | my $num = ord(substr($key, $tag->{ch} + 1, 1)); |
363 | |
364 | if ($offsets[$num]) { |
251dfd0e |
365 | my $offset = $offsets[$num] + DBM::Deep->SIG_SIZE + $self->{data_size}; |
20f7b20c |
366 | seek($fh, $offset + $root->{file_offset}, SEEK_SET); |
367 | my $subkeys; |
251dfd0e |
368 | read( $fh, $subkeys, $self->{bucket_list_size}); |
20f7b20c |
369 | |
251dfd0e |
370 | for (my $k=0; $k<$self->{max_buckets}; $k++) { |
371 | my $subloc = unpack($self->{long_pack}, substr($subkeys, ($k * $self->{bucket_size}) + |
372 | $self->{hash_size}, $self->{long_size})); |
20f7b20c |
373 | if (!$subloc) { |
251dfd0e |
374 | seek($fh, $offset + ($k * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
375 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
20f7b20c |
376 | last; |
377 | } |
378 | } # k loop |
379 | } |
380 | else { |
381 | $offsets[$num] = $root->{end}; |
251dfd0e |
382 | seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET); |
383 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
20f7b20c |
384 | |
251dfd0e |
385 | my $blist_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_BLIST, chr(0) x $self->{bucket_list_size}); |
20f7b20c |
386 | |
387 | seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET); |
251dfd0e |
388 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
20f7b20c |
389 | } |
390 | } # key is real |
391 | } # i loop |
392 | |
393 | $location ||= $root->{end}; |
394 | } # re-index bucket list |
395 | |
396 | ## |
397 | # Seek to content area and store signature, value and plaintext key |
398 | ## |
399 | if ($location) { |
400 | my $content_length; |
401 | seek($fh, $location + $root->{file_offset}, SEEK_SET); |
402 | |
403 | ## |
404 | # Write signature based on content type, set content length and write actual value. |
405 | ## |
406 | my $r = Scalar::Util::reftype($value) || ''; |
407 | if ($r eq 'HASH') { |
408 | print( $fh DBM::Deep->TYPE_HASH ); |
251dfd0e |
409 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
ec1bce6b |
410 | $content_length = $self->{index_size}; |
20f7b20c |
411 | } |
412 | elsif ($r eq 'ARRAY') { |
413 | print( $fh DBM::Deep->TYPE_ARRAY ); |
251dfd0e |
414 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
ec1bce6b |
415 | $content_length = $self->{index_size}; |
20f7b20c |
416 | } |
417 | elsif (!defined($value)) { |
418 | print( $fh DBM::Deep->SIG_NULL ); |
251dfd0e |
419 | print( $fh pack($self->{data_pack}, 0) ); |
20f7b20c |
420 | $content_length = 0; |
421 | } |
422 | else { |
423 | print( $fh DBM::Deep->SIG_DATA ); |
251dfd0e |
424 | print( $fh pack($self->{data_pack}, length($value)) . $value ); |
20f7b20c |
425 | $content_length = length($value); |
426 | } |
427 | |
428 | ## |
429 | # Plain key is stored AFTER value, as keys are typically fetched less often. |
430 | ## |
251dfd0e |
431 | print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key ); |
20f7b20c |
432 | |
433 | ## |
434 | # If value is blessed, preserve class name |
435 | ## |
436 | if ( $root->{autobless} ) { |
437 | my $value_class = Scalar::Util::blessed($value); |
438 | if ( defined $value_class && $value_class ne 'DBM::Deep' ) { |
439 | ## |
440 | # Blessed ref -- will restore later |
441 | ## |
442 | print( $fh chr(1) ); |
251dfd0e |
443 | print( $fh pack($self->{data_pack}, length($value_class)) . $value_class ); |
20f7b20c |
444 | $content_length += 1; |
251dfd0e |
445 | $content_length += $self->{data_size} + length($value_class); |
20f7b20c |
446 | } |
447 | else { |
448 | print( $fh chr(0) ); |
449 | $content_length += 1; |
450 | } |
451 | } |
452 | |
453 | ## |
454 | # If this is a new content area, advance EOF counter |
455 | ## |
456 | if ($location == $root->{end}) { |
457 | $root->{end} += DBM::Deep->SIG_SIZE; |
251dfd0e |
458 | $root->{end} += $self->{data_size} + $content_length; |
459 | $root->{end} += $self->{data_size} + length($plain_key); |
20f7b20c |
460 | } |
461 | |
462 | ## |
463 | # If content is a hash or array, create new child DBM::Deep object and |
464 | # pass each key or element to it. |
465 | ## |
466 | if ($r eq 'HASH') { |
467 | my $branch = DBM::Deep->new( |
468 | type => DBM::Deep->TYPE_HASH, |
469 | base_offset => $location, |
470 | root => $root, |
471 | ); |
472 | foreach my $key (keys %{$value}) { |
473 | $branch->STORE( $key, $value->{$key} ); |
474 | } |
475 | } |
476 | elsif ($r eq 'ARRAY') { |
477 | my $branch = DBM::Deep->new( |
478 | type => DBM::Deep->TYPE_ARRAY, |
479 | base_offset => $location, |
480 | root => $root, |
481 | ); |
482 | my $index = 0; |
483 | foreach my $element (@{$value}) { |
484 | $branch->STORE( $index, $element ); |
485 | $index++; |
486 | } |
487 | } |
488 | |
489 | return $result; |
490 | } |
d4b1166e |
491 | |
20f7b20c |
492 | return $obj->_throw_error("Fatal error: indexing failed -- possibly due to corruption in file"); |
d4b1166e |
493 | } |
494 | |
9020ee8c |
495 | sub get_bucket_value { |
beac1dff |
496 | ## |
497 | # Fetch single value given tag and MD5 digested key. |
498 | ## |
499 | my $self = shift; |
500 | my ($obj, $tag, $md5) = @_; |
501 | my $keys = $tag->{content}; |
9020ee8c |
502 | |
503 | my $fh = $obj->_fh; |
504 | |
beac1dff |
505 | ## |
506 | # Iterate through buckets, looking for a key match |
507 | ## |
9020ee8c |
508 | BUCKET: |
beac1dff |
509 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
510 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
511 | my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size})); |
9020ee8c |
512 | |
beac1dff |
513 | if (!$subloc) { |
514 | ## |
515 | # Hit end of list, no match |
516 | ## |
517 | return; |
518 | } |
9020ee8c |
519 | |
520 | if ( $md5 ne $key ) { |
521 | next BUCKET; |
522 | } |
523 | |
524 | ## |
525 | # Found match -- seek to offset and read signature |
526 | ## |
527 | my $signature; |
528 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
529 | read( $fh, $signature, DBM::Deep->SIG_SIZE); |
d0b74c17 |
530 | |
9020ee8c |
531 | ## |
532 | # If value is a hash or array, return new DBM::Deep object with correct offset |
533 | ## |
534 | if (($signature eq DBM::Deep->TYPE_HASH) || ($signature eq DBM::Deep->TYPE_ARRAY)) { |
535 | my $obj = DBM::Deep->new( |
536 | type => $signature, |
537 | base_offset => $subloc, |
538 | root => $obj->_root, |
539 | ); |
d0b74c17 |
540 | |
9020ee8c |
541 | if ($obj->_root->{autobless}) { |
542 | ## |
543 | # Skip over value and plain key to see if object needs |
544 | # to be re-blessed |
545 | ## |
251dfd0e |
546 | seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR); |
d0b74c17 |
547 | |
9020ee8c |
548 | my $size; |
251dfd0e |
549 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
9020ee8c |
550 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
551 | |
9020ee8c |
552 | my $bless_bit; |
553 | read( $fh, $bless_bit, 1); |
554 | if (ord($bless_bit)) { |
555 | ## |
556 | # Yes, object needs to be re-blessed |
557 | ## |
558 | my $class_name; |
251dfd0e |
559 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
9020ee8c |
560 | if ($size) { read( $fh, $class_name, $size); } |
561 | if ($class_name) { $obj = bless( $obj, $class_name ); } |
562 | } |
563 | } |
d0b74c17 |
564 | |
9020ee8c |
565 | return $obj; |
566 | } |
d0b74c17 |
567 | |
9020ee8c |
568 | ## |
569 | # Otherwise return actual value |
570 | ## |
571 | elsif ($signature eq DBM::Deep->SIG_DATA) { |
572 | my $size; |
573 | my $value = ''; |
251dfd0e |
574 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
9020ee8c |
575 | if ($size) { read( $fh, $value, $size); } |
576 | return $value; |
577 | } |
d0b74c17 |
578 | |
9020ee8c |
579 | ## |
580 | # Key exists, but content is null |
581 | ## |
582 | else { return; } |
beac1dff |
583 | } # i loop |
9020ee8c |
584 | |
beac1dff |
585 | return; |
9020ee8c |
586 | } |
ab0e4957 |
587 | |
588 | sub delete_bucket { |
beac1dff |
589 | ## |
590 | # Delete single key/value pair given tag and MD5 digested key. |
591 | ## |
592 | my $self = shift; |
593 | my ($obj, $tag, $md5) = @_; |
594 | my $keys = $tag->{content}; |
ab0e4957 |
595 | |
596 | my $fh = $obj->_fh; |
d0b74c17 |
597 | |
beac1dff |
598 | ## |
599 | # Iterate through buckets, looking for a key match |
600 | ## |
ab0e4957 |
601 | BUCKET: |
beac1dff |
602 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
603 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
604 | my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size})); |
ab0e4957 |
605 | |
beac1dff |
606 | if (!$subloc) { |
607 | ## |
608 | # Hit end of list, no match |
609 | ## |
610 | return; |
611 | } |
ab0e4957 |
612 | |
613 | if ( $md5 ne $key ) { |
614 | next BUCKET; |
615 | } |
616 | |
617 | ## |
618 | # Matched key -- delete bucket and return |
619 | ## |
251dfd0e |
620 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $obj->_root->{file_offset}, SEEK_SET); |
621 | print( $fh substr($keys, ($i+1) * $self->{bucket_size} ) ); |
622 | print( $fh chr(0) x $self->{bucket_size} ); |
d0b74c17 |
623 | |
ab0e4957 |
624 | return 1; |
beac1dff |
625 | } # i loop |
ab0e4957 |
626 | |
beac1dff |
627 | return; |
ab0e4957 |
628 | } |
629 | |
912d50b1 |
630 | sub bucket_exists { |
beac1dff |
631 | ## |
632 | # Check existence of single key given tag and MD5 digested key. |
633 | ## |
634 | my $self = shift; |
635 | my ($obj, $tag, $md5) = @_; |
636 | my $keys = $tag->{content}; |
d0b74c17 |
637 | |
beac1dff |
638 | ## |
639 | # Iterate through buckets, looking for a key match |
640 | ## |
912d50b1 |
641 | BUCKET: |
beac1dff |
642 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
643 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
644 | my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size})); |
912d50b1 |
645 | |
beac1dff |
646 | if (!$subloc) { |
647 | ## |
648 | # Hit end of list, no match |
649 | ## |
650 | return; |
651 | } |
912d50b1 |
652 | |
653 | if ( $md5 ne $key ) { |
654 | next BUCKET; |
655 | } |
656 | |
657 | ## |
658 | # Matched key -- return true |
659 | ## |
660 | return 1; |
beac1dff |
661 | } # i loop |
912d50b1 |
662 | |
beac1dff |
663 | return; |
912d50b1 |
664 | } |
665 | |
6736c116 |
666 | sub find_bucket_list { |
beac1dff |
667 | ## |
668 | # Locate offset for bucket list, given digested key |
669 | ## |
670 | my $self = shift; |
d0b74c17 |
671 | my ($obj, $md5, $args) = @_; |
672 | $args = {} unless $args; |
673 | |
beac1dff |
674 | ## |
675 | # Locate offset for bucket list using digest index system |
676 | ## |
677 | my $ch = 0; |
678 | my $tag = $self->load_tag($obj, $obj->_base_offset); |
d0b74c17 |
679 | if (!$tag) { |
680 | return $self->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
681 | } |
682 | |
beac1dff |
683 | while ($tag->{signature} ne DBM::Deep->SIG_BLIST) { |
d0b74c17 |
684 | my $num = ord substr($md5, $ch, 1); |
685 | |
686 | my $ref_loc = $tag->{offset} + ($num * $self->{long_size}); |
687 | $tag = $self->index_lookup( $obj, $tag, $num ); |
688 | |
689 | if (!$tag) { |
690 | if ( $args->{create} ) { |
691 | my $fh = $obj->_fh; |
692 | seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET); |
693 | print( $fh pack($self->{long_pack}, $obj->_root->{end}) ); |
694 | |
695 | $tag = $self->create_tag( |
696 | $obj, $obj->_root->{end}, |
697 | DBM::Deep->SIG_BLIST, |
698 | chr(0) x $self->{bucket_list_size}, |
699 | ); |
700 | |
701 | $tag->{ref_loc} = $ref_loc; |
702 | $tag->{ch} = $ch; |
703 | |
704 | last; |
705 | } |
706 | else { |
707 | return; |
708 | } |
709 | } |
710 | |
711 | $tag->{ch} = $ch; |
712 | $tag->{ref_loc} = $ref_loc; |
713 | |
beac1dff |
714 | $ch++; |
715 | } |
d0b74c17 |
716 | |
beac1dff |
717 | return $tag; |
6736c116 |
718 | } |
719 | |
d0b74c17 |
720 | sub index_lookup { |
721 | ## |
722 | # Given index tag, lookup single entry in index and return . |
723 | ## |
724 | my $self = shift; |
725 | my ($obj, $tag, $index) = @_; |
726 | |
727 | my $location = unpack( |
728 | $self->{long_pack}, |
729 | substr( |
730 | $tag->{content}, |
731 | $index * $self->{long_size}, |
732 | $self->{long_size}, |
733 | ), |
734 | ); |
735 | |
736 | if (!$location) { return; } |
737 | |
738 | return $self->load_tag( $obj, $location ); |
739 | } |
740 | |
6736c116 |
741 | sub traverse_index { |
beac1dff |
742 | ## |
743 | # Scan index and recursively step into deeper levels, looking for next key. |
744 | ## |
6736c116 |
745 | my $self = shift; |
746 | my ($obj, $offset, $ch, $force_return_next) = @_; |
747 | $force_return_next = undef unless $force_return_next; |
d0b74c17 |
748 | |
beac1dff |
749 | my $tag = $self->load_tag($obj, $offset ); |
6736c116 |
750 | |
751 | my $fh = $obj->_fh; |
d0b74c17 |
752 | |
beac1dff |
753 | if ($tag->{signature} ne DBM::Deep->SIG_BLIST) { |
754 | my $content = $tag->{content}; |
755 | my $start; |
756 | if ($obj->{return_next}) { $start = 0; } |
757 | else { $start = ord(substr($obj->{prev_md5}, $ch, 1)); } |
d0b74c17 |
758 | |
beac1dff |
759 | for (my $index = $start; $index < 256; $index++) { |
760 | my $subloc = unpack($self->{long_pack}, substr($content, $index * $self->{long_size}, $self->{long_size}) ); |
761 | if ($subloc) { |
762 | my $result = $self->traverse_index( $obj, $subloc, $ch + 1, $force_return_next ); |
763 | if (defined($result)) { return $result; } |
764 | } |
765 | } # index loop |
d0b74c17 |
766 | |
beac1dff |
767 | $obj->{return_next} = 1; |
768 | } # tag is an index |
d0b74c17 |
769 | |
beac1dff |
770 | elsif ($tag->{signature} eq DBM::Deep->SIG_BLIST) { |
771 | my $keys = $tag->{content}; |
772 | if ($force_return_next) { $obj->{return_next} = 1; } |
d0b74c17 |
773 | |
beac1dff |
774 | ## |
775 | # Iterate through buckets, looking for a key match |
776 | ## |
777 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
778 | my $key = substr($keys, $i * $self->{bucket_size}, $self->{hash_size}); |
779 | my $subloc = unpack($self->{long_pack}, substr($keys, ($i * $self->{bucket_size}) + $self->{hash_size}, $self->{long_size})); |
d0b74c17 |
780 | |
beac1dff |
781 | if (!$subloc) { |
782 | ## |
783 | # End of bucket list -- return to outer loop |
784 | ## |
785 | $obj->{return_next} = 1; |
786 | last; |
787 | } |
788 | elsif ($key eq $obj->{prev_md5}) { |
789 | ## |
790 | # Located previous key -- return next one found |
791 | ## |
792 | $obj->{return_next} = 1; |
793 | next; |
794 | } |
795 | elsif ($obj->{return_next}) { |
796 | ## |
797 | # Seek to bucket location and skip over signature |
798 | ## |
799 | seek($fh, $subloc + DBM::Deep->SIG_SIZE + $obj->_root->{file_offset}, SEEK_SET); |
d0b74c17 |
800 | |
beac1dff |
801 | ## |
802 | # Skip over value to get to plain key |
803 | ## |
804 | my $size; |
805 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
806 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
807 | |
beac1dff |
808 | ## |
809 | # Read in plain key and return as scalar |
810 | ## |
811 | my $plain_key; |
812 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
813 | if ($size) { read( $fh, $plain_key, $size); } |
d0b74c17 |
814 | |
beac1dff |
815 | return $plain_key; |
816 | } |
817 | } # bucket loop |
d0b74c17 |
818 | |
beac1dff |
819 | $obj->{return_next} = 1; |
820 | } # tag is a bucket list |
d0b74c17 |
821 | |
beac1dff |
822 | return; |
6736c116 |
823 | } |
824 | |
825 | sub get_next_key { |
beac1dff |
826 | ## |
827 | # Locate next key, given digested previous one |
828 | ## |
6736c116 |
829 | my $self = shift; |
830 | my ($obj) = @_; |
d0b74c17 |
831 | |
beac1dff |
832 | $obj->{prev_md5} = $_[1] ? $_[1] : undef; |
833 | $obj->{return_next} = 0; |
d0b74c17 |
834 | |
beac1dff |
835 | ## |
836 | # If the previous key was not specifed, start at the top and |
837 | # return the first one found. |
838 | ## |
839 | if (!$obj->{prev_md5}) { |
840 | $obj->{prev_md5} = chr(0) x $self->{hash_size}; |
841 | $obj->{return_next} = 1; |
842 | } |
d0b74c17 |
843 | |
beac1dff |
844 | return $self->traverse_index( $obj, $obj->_base_offset, 0 ); |
6736c116 |
845 | } |
846 | |
a20d9a3f |
847 | 1; |
848 | __END__ |