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 | ## |
75be6413 |
28 | # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4 |
29 | # GB per file. |
beac1dff |
30 | # (Perl must be compiled with largefile support for files > 2 GB) |
81d16922 |
31 | # |
32 | # Set to 8 and 'Q' for 64-bit offsets. Theoretical limit of 16 XB per file. |
beac1dff |
33 | # (Perl must be compiled with largefile and 64-bit long support) |
81d16922 |
34 | ## |
251dfd0e |
35 | $self->{long_size} = $long_s ? $long_s : 4; |
36 | $self->{long_pack} = $long_p ? $long_p : 'N'; |
1bf65be7 |
37 | |
81d16922 |
38 | ## |
75be6413 |
39 | # Set to 4 and 'N' for 32-bit data length prefixes. Limit of 4 GB for each |
40 | # key/value. Upgrading this is possible (see above) but probably not necessary. |
41 | # If you need more than 4 GB for a single key or value, this module is really |
42 | # not for you :-) |
81d16922 |
43 | ## |
251dfd0e |
44 | $self->{data_size} = $data_s ? $data_s : 4; |
45 | $self->{data_pack} = $data_p ? $data_p : 'N'; |
1bf65be7 |
46 | |
beac1dff |
47 | return $self->precalc_sizes(); |
1bf65be7 |
48 | } |
49 | |
50 | sub set_digest { |
beac1dff |
51 | ## |
52 | # Set key digest function (default is MD5) |
53 | ## |
251dfd0e |
54 | my $self = shift; |
1bf65be7 |
55 | my ($digest_func, $hash_size) = @_; |
56 | |
d0b74c17 |
57 | $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5; |
251dfd0e |
58 | $self->{hash_size} = $hash_size ? $hash_size : 16; |
612969fb |
59 | |
beac1dff |
60 | return $self->precalc_sizes(); |
612969fb |
61 | } |
62 | |
63 | sub new { |
64 | my $class = shift; |
65 | my ($args) = @_; |
66 | |
67 | my $self = bless { |
68 | long_size => 4, |
69 | long_pack => 'N', |
70 | data_size => 4, |
71 | data_pack => 'N', |
251dfd0e |
72 | |
612969fb |
73 | digest => \&Digest::MD5::md5, |
74 | hash_size => 16, |
251dfd0e |
75 | |
81d16922 |
76 | ## |
77 | # Maximum number of buckets per list before another level of indexing is done. |
78 | # Increase this value for slightly greater speed, but larger database files. |
79 | # DO NOT decrease this value below 16, due to risk of recursive reindex overrun. |
80 | ## |
612969fb |
81 | max_buckets => 16, |
82 | }, $class; |
83 | |
251dfd0e |
84 | $self->precalc_sizes; |
612969fb |
85 | |
86 | return $self; |
1bf65be7 |
87 | } |
88 | |
70b55428 |
89 | sub setup_fh { |
90 | my $self = shift; |
91 | my ($obj) = @_; |
92 | |
93 | $self->open( $obj ) if !defined $obj->_fh; |
94 | |
673464d9 |
95 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
70b55428 |
96 | unless ( $obj->_root->{inode} ) { |
97 | my @stats = stat($obj->_fh); |
98 | $obj->_root->{inode} = $stats[1]; |
99 | $obj->_root->{end} = $stats[7]; |
100 | } |
101 | |
102 | return 1; |
103 | } |
104 | |
a20d9a3f |
105 | sub open { |
20f7b20c |
106 | ## |
107 | # Open a fh to the database, create if nonexistent. |
108 | # Make sure file signature matches DBM::Deep spec. |
109 | ## |
a20d9a3f |
110 | my $self = shift; |
70b55428 |
111 | my ($obj) = @_; |
a20d9a3f |
112 | |
3d1b8be9 |
113 | if (defined($obj->_fh)) { $self->close_fh( $obj ); } |
20f7b20c |
114 | |
673464d9 |
115 | # Theoretically, adding O_BINARY should remove the need for the binmode |
116 | # Of course, testing it is going to be ... interesting. |
117 | my $flags = O_RDWR | O_CREAT | O_BINARY; |
a20d9a3f |
118 | |
673464d9 |
119 | my $fh; |
120 | sysopen( $fh, $obj->_root->{file}, $flags ) |
121 | or $obj->_throw_error("Cannot sysopen file: " . $obj->_root->{file} . ": $!"); |
122 | $obj->_root->{fh} = $fh; |
a20d9a3f |
123 | |
124 | #XXX Can we remove this by using the right sysopen() flags? |
125 | # Maybe ... q.v. above |
126 | binmode $fh; # for win32 |
127 | |
cd59cad8 |
128 | if ($obj->_root->{autoflush}) { |
a20d9a3f |
129 | my $old = select $fh; |
130 | $|=1; |
131 | select $old; |
132 | } |
20f7b20c |
133 | |
cd59cad8 |
134 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
a20d9a3f |
135 | |
136 | my $signature; |
137 | my $bytes_read = read( $fh, $signature, length(DBM::Deep->SIG_FILE)); |
20f7b20c |
138 | |
a20d9a3f |
139 | ## |
140 | # File is empty -- write signature and master index |
141 | ## |
142 | if (!$bytes_read) { |
cd59cad8 |
143 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
a20d9a3f |
144 | print( $fh DBM::Deep->SIG_FILE); |
d0b74c17 |
145 | |
ec1bce6b |
146 | $self->create_tag($obj, $obj->_base_offset, $obj->_type, chr(0) x $self->{index_size}); |
a20d9a3f |
147 | |
e5fc7e69 |
148 | # Why is this being printed here? I'm not seeing where anything actually points to |
149 | # this spot. |
150 | #XXX $obj->_root->{end} isn't updated from these 10 bytes that are being written |
a20d9a3f |
151 | my $plain_key = "[base]"; |
251dfd0e |
152 | print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key ); |
a20d9a3f |
153 | |
154 | # Flush the filehandle |
155 | my $old_fh = select $fh; |
156 | my $old_af = $|; $| = 1; $| = $old_af; |
157 | select $old_fh; |
158 | |
a20d9a3f |
159 | return 1; |
160 | } |
20f7b20c |
161 | |
a20d9a3f |
162 | ## |
163 | # Check signature was valid |
164 | ## |
165 | unless ($signature eq DBM::Deep->SIG_FILE) { |
3d1b8be9 |
166 | $self->close_fh( $obj ); |
e5fc7e69 |
167 | $obj->_throw_error("Signature not found -- file is not a Deep DB"); |
a20d9a3f |
168 | } |
169 | |
a20d9a3f |
170 | ## |
171 | # Get our type from master index signature |
172 | ## |
e5fc7e69 |
173 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
174 | or $obj->_throw_error("Corrupted file, no master index record"); |
d0b74c17 |
175 | |
e5fc7e69 |
176 | unless ($obj->{type} eq $tag->{signature}) { |
177 | $obj->_throw_error("File type mismatch"); |
a20d9a3f |
178 | } |
20f7b20c |
179 | |
d0b74c17 |
180 | #XXX We probably also want to store the hash algorithm name and not assume anything |
181 | #XXX The cool thing would be to allow a different hashing algorithm at every level |
182 | |
a20d9a3f |
183 | return 1; |
184 | } |
185 | |
3d1b8be9 |
186 | sub close_fh { |
cd59cad8 |
187 | my $self = shift; |
a21f2d90 |
188 | my ($obj) = @_; |
cd59cad8 |
189 | |
190 | if ( my $fh = $obj->_root->{fh} ) { |
191 | close $fh; |
192 | } |
193 | $obj->_root->{fh} = undef; |
194 | |
195 | return 1; |
196 | } |
197 | |
d4b1166e |
198 | sub create_tag { |
20f7b20c |
199 | ## |
200 | # Given offset, signature and content, create tag and write to disk |
201 | ## |
d4b1166e |
202 | my $self = shift; |
20f7b20c |
203 | my ($obj, $offset, $sig, $content) = @_; |
204 | my $size = length($content); |
205 | |
d4b1166e |
206 | my $fh = $obj->_fh; |
207 | |
20f7b20c |
208 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
251dfd0e |
209 | print( $fh $sig . pack($self->{data_pack}, $size) . $content ); |
20f7b20c |
210 | |
211 | if ($offset == $obj->_root->{end}) { |
251dfd0e |
212 | $obj->_root->{end} += DBM::Deep->SIG_SIZE + $self->{data_size} + $size; |
20f7b20c |
213 | } |
214 | |
215 | return { |
216 | signature => $sig, |
217 | size => $size, |
251dfd0e |
218 | offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size}, |
20f7b20c |
219 | content => $content |
220 | }; |
d4b1166e |
221 | } |
222 | |
223 | sub load_tag { |
20f7b20c |
224 | ## |
225 | # Given offset, load single tag and return signature, size and data |
226 | ## |
d4b1166e |
227 | my $self = shift; |
20f7b20c |
228 | my ($obj, $offset) = @_; |
229 | |
d4b1166e |
230 | my $fh = $obj->_fh; |
231 | |
20f7b20c |
232 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
e5fc7e69 |
233 | |
75be6413 |
234 | #XXX I'm not sure this check will work if autoflush isn't enabled ... |
e5fc7e69 |
235 | return if eof $fh; |
20f7b20c |
236 | |
d4b1166e |
237 | my $b; |
251dfd0e |
238 | read( $fh, $b, DBM::Deep->SIG_SIZE + $self->{data_size} ); |
239 | my ($sig, $size) = unpack( "A $self->{data_pack}", $b ); |
20f7b20c |
240 | |
241 | my $buffer; |
242 | read( $fh, $buffer, $size); |
243 | |
244 | return { |
245 | signature => $sig, |
246 | size => $size, |
251dfd0e |
247 | offset => $offset + DBM::Deep->SIG_SIZE + $self->{data_size}, |
20f7b20c |
248 | content => $buffer |
249 | }; |
d4b1166e |
250 | } |
251 | |
20f7b20c |
252 | sub add_bucket { |
253 | ## |
254 | # Adds one key/value pair to bucket list, given offset, MD5 digest of key, |
255 | # plain (undigested) key and value. |
256 | ## |
d4b1166e |
257 | my $self = shift; |
20f7b20c |
258 | my ($obj, $tag, $md5, $plain_key, $value) = @_; |
75be6413 |
259 | |
20f7b20c |
260 | my $keys = $tag->{content}; |
261 | my $location = 0; |
262 | my $result = 2; |
263 | |
264 | my $root = $obj->_root; |
265 | |
266 | my $is_dbm_deep = eval { local $SIG{'__DIE__'}; $value->isa( 'DBM::Deep' ) }; |
267 | my $internal_ref = $is_dbm_deep && ($value->_root eq $root); |
268 | |
269 | my $fh = $obj->_fh; |
270 | |
271 | ## |
272 | # Iterate through buckets, seeing if this is a new entry or a replace. |
273 | ## |
75be6413 |
274 | BUCKET: |
d0b74c17 |
275 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
9cec1360 |
276 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
75be6413 |
277 | |
20f7b20c |
278 | if (!$subloc) { |
279 | ## |
280 | # Found empty bucket (end of list). Populate and exit loop. |
281 | ## |
282 | $result = 2; |
283 | |
284 | $location = $internal_ref |
285 | ? $value->_base_offset |
286 | : $root->{end}; |
e5fc7e69 |
287 | print "NEW: $location\n"; |
20f7b20c |
288 | |
75be6413 |
289 | seek( |
290 | $fh, |
291 | $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, |
292 | SEEK_SET, |
293 | ); |
294 | |
251dfd0e |
295 | print( $fh $md5 . pack($self->{long_pack}, $location) ); |
20f7b20c |
296 | last; |
297 | } |
298 | |
75be6413 |
299 | if ( $md5 ne $key ) { |
300 | next BUCKET; |
301 | } |
20f7b20c |
302 | |
75be6413 |
303 | ## |
304 | # Found existing bucket with same key. Replace with new value. |
305 | ## |
306 | $result = 1; |
20f7b20c |
307 | |
75be6413 |
308 | if ($internal_ref) { |
309 | $location = $value->_base_offset; |
310 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
311 | print( $fh $md5 . pack($self->{long_pack}, $location) ); |
312 | return $result; |
313 | } |
20f7b20c |
314 | |
75be6413 |
315 | seek($fh, $subloc + DBM::Deep->SIG_SIZE + $root->{file_offset}, SEEK_SET); |
316 | my $size; |
317 | read( $fh, $size, $self->{data_size}); |
318 | $size = unpack($self->{data_pack}, $size); |
20f7b20c |
319 | |
75be6413 |
320 | ## |
321 | # If value is a hash, array, or raw value with equal or less size, we can |
322 | # reuse the same content area of the database. Otherwise, we have to create |
323 | # a new content area at the EOF. |
324 | ## |
325 | my $actual_length; |
326 | my $r = Scalar::Util::reftype( $value ) || ''; |
327 | if ( $r eq 'HASH' || $r eq 'ARRAY' ) { |
328 | $actual_length = $self->{index_size}; |
329 | |
330 | # if autobless is enabled, must also take into consideration |
331 | # the class name, as it is stored along with key/value. |
332 | if ( $root->{autobless} ) { |
333 | my $value_class = Scalar::Util::blessed($value); |
334 | if ( defined $value_class && !$value->isa('DBM::Deep') ) { |
335 | $actual_length += length($value_class); |
336 | } |
20f7b20c |
337 | } |
75be6413 |
338 | } |
339 | else { $actual_length = length($value); } |
20f7b20c |
340 | |
75be6413 |
341 | if ($actual_length <= $size) { |
342 | $location = $subloc; |
20f7b20c |
343 | } |
75be6413 |
344 | else { |
345 | $location = $root->{end}; |
346 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $self->{hash_size} + $root->{file_offset}, SEEK_SET); |
347 | print( $fh pack($self->{long_pack}, $location) ); |
348 | } |
349 | |
350 | last; |
20f7b20c |
351 | } |
352 | |
353 | ## |
354 | # If this is an internal reference, return now. |
355 | # No need to write value or plain key |
356 | ## |
75be6413 |
357 | #XXX We need to store the key as a reference to the internal spot |
20f7b20c |
358 | if ($internal_ref) { |
359 | return $result; |
360 | } |
361 | |
362 | ## |
363 | # If bucket didn't fit into list, split into a new index level |
364 | ## |
365 | if (!$location) { |
75be6413 |
366 | # re-index bucket list |
20f7b20c |
367 | |
75be6413 |
368 | $self->split_index( $obj, $md5, $tag ); |
20f7b20c |
369 | |
75be6413 |
370 | $location = $root->{end}; |
371 | } |
20f7b20c |
372 | |
373 | ## |
374 | # Seek to content area and store signature, value and plaintext key |
375 | ## |
376 | if ($location) { |
377 | my $content_length; |
378 | seek($fh, $location + $root->{file_offset}, SEEK_SET); |
379 | |
380 | ## |
381 | # Write signature based on content type, set content length and write actual value. |
382 | ## |
383 | my $r = Scalar::Util::reftype($value) || ''; |
384 | if ($r eq 'HASH') { |
385 | print( $fh DBM::Deep->TYPE_HASH ); |
251dfd0e |
386 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
ec1bce6b |
387 | $content_length = $self->{index_size}; |
20f7b20c |
388 | } |
389 | elsif ($r eq 'ARRAY') { |
390 | print( $fh DBM::Deep->TYPE_ARRAY ); |
251dfd0e |
391 | print( $fh pack($self->{data_pack}, $self->{index_size}) . chr(0) x $self->{index_size} ); |
ec1bce6b |
392 | $content_length = $self->{index_size}; |
20f7b20c |
393 | } |
394 | elsif (!defined($value)) { |
395 | print( $fh DBM::Deep->SIG_NULL ); |
251dfd0e |
396 | print( $fh pack($self->{data_pack}, 0) ); |
20f7b20c |
397 | $content_length = 0; |
398 | } |
399 | else { |
400 | print( $fh DBM::Deep->SIG_DATA ); |
251dfd0e |
401 | print( $fh pack($self->{data_pack}, length($value)) . $value ); |
20f7b20c |
402 | $content_length = length($value); |
403 | } |
404 | |
405 | ## |
406 | # Plain key is stored AFTER value, as keys are typically fetched less often. |
407 | ## |
251dfd0e |
408 | print( $fh pack($self->{data_pack}, length($plain_key)) . $plain_key ); |
20f7b20c |
409 | |
410 | ## |
411 | # If value is blessed, preserve class name |
412 | ## |
413 | if ( $root->{autobless} ) { |
414 | my $value_class = Scalar::Util::blessed($value); |
415 | if ( defined $value_class && $value_class ne 'DBM::Deep' ) { |
416 | ## |
417 | # Blessed ref -- will restore later |
418 | ## |
419 | print( $fh chr(1) ); |
251dfd0e |
420 | print( $fh pack($self->{data_pack}, length($value_class)) . $value_class ); |
20f7b20c |
421 | $content_length += 1; |
251dfd0e |
422 | $content_length += $self->{data_size} + length($value_class); |
20f7b20c |
423 | } |
424 | else { |
425 | print( $fh chr(0) ); |
426 | $content_length += 1; |
427 | } |
428 | } |
429 | |
430 | ## |
431 | # If this is a new content area, advance EOF counter |
432 | ## |
433 | if ($location == $root->{end}) { |
434 | $root->{end} += DBM::Deep->SIG_SIZE; |
251dfd0e |
435 | $root->{end} += $self->{data_size} + $content_length; |
436 | $root->{end} += $self->{data_size} + length($plain_key); |
20f7b20c |
437 | } |
438 | |
439 | ## |
440 | # If content is a hash or array, create new child DBM::Deep object and |
441 | # pass each key or element to it. |
442 | ## |
443 | if ($r eq 'HASH') { |
444 | my $branch = DBM::Deep->new( |
445 | type => DBM::Deep->TYPE_HASH, |
446 | base_offset => $location, |
447 | root => $root, |
448 | ); |
449 | foreach my $key (keys %{$value}) { |
450 | $branch->STORE( $key, $value->{$key} ); |
451 | } |
452 | } |
453 | elsif ($r eq 'ARRAY') { |
454 | my $branch = DBM::Deep->new( |
455 | type => DBM::Deep->TYPE_ARRAY, |
456 | base_offset => $location, |
457 | root => $root, |
458 | ); |
459 | my $index = 0; |
460 | foreach my $element (@{$value}) { |
461 | $branch->STORE( $index, $element ); |
462 | $index++; |
463 | } |
464 | } |
465 | |
466 | return $result; |
467 | } |
d4b1166e |
468 | |
e5fc7e69 |
469 | $obj->_throw_error("Fatal error: indexing failed -- possibly due to corruption in file"); |
d4b1166e |
470 | } |
471 | |
75be6413 |
472 | sub split_index { |
473 | my $self = shift; |
474 | my ($obj, $md5, $tag) = @_; |
475 | |
476 | my $fh = $obj->_fh; |
477 | my $root = $obj->_root; |
478 | my $keys = $tag->{content}; |
479 | |
480 | seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET); |
481 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
482 | |
483 | my $index_tag = $self->create_tag( |
484 | $obj, |
485 | $root->{end}, |
486 | DBM::Deep->SIG_INDEX, |
487 | chr(0) x $self->{index_size}, |
488 | ); |
489 | |
490 | my @offsets = (); |
491 | |
492 | $keys .= $md5 . pack($self->{long_pack}, 0); |
493 | |
494 | BUCKET: |
495 | for (my $i = 0; $i <= $self->{max_buckets}; $i++) { |
9cec1360 |
496 | my ($key, $old_subloc) = $self->_get_key_subloc( $keys, $i ); |
75be6413 |
497 | |
498 | next BUCKET unless $key; |
499 | |
75be6413 |
500 | my $num = ord(substr($key, $tag->{ch} + 1, 1)); |
501 | |
502 | if ($offsets[$num]) { |
503 | my $offset = $offsets[$num] + DBM::Deep->SIG_SIZE + $self->{data_size}; |
504 | seek($fh, $offset + $root->{file_offset}, SEEK_SET); |
505 | my $subkeys; |
506 | read( $fh, $subkeys, $self->{bucket_list_size}); |
507 | |
508 | for (my $k=0; $k<$self->{max_buckets}; $k++) { |
9cec1360 |
509 | my ($temp, $subloc) = $self->_get_key_subloc( $subkeys, $k ); |
75be6413 |
510 | |
511 | if (!$subloc) { |
512 | seek($fh, $offset + ($k * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
513 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
514 | last; |
515 | } |
516 | } # k loop |
517 | } |
518 | else { |
519 | $offsets[$num] = $root->{end}; |
520 | seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET); |
521 | print( $fh pack($self->{long_pack}, $root->{end}) ); |
522 | |
523 | my $blist_tag = $self->create_tag($obj, $root->{end}, DBM::Deep->SIG_BLIST, chr(0) x $self->{bucket_list_size}); |
524 | |
525 | seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET); |
526 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
527 | } |
528 | } # i loop |
529 | |
530 | return; |
531 | } |
532 | |
9020ee8c |
533 | sub get_bucket_value { |
beac1dff |
534 | ## |
535 | # Fetch single value given tag and MD5 digested key. |
536 | ## |
537 | my $self = shift; |
538 | my ($obj, $tag, $md5) = @_; |
539 | my $keys = $tag->{content}; |
9020ee8c |
540 | |
541 | my $fh = $obj->_fh; |
542 | |
beac1dff |
543 | ## |
544 | # Iterate through buckets, looking for a key match |
545 | ## |
9020ee8c |
546 | BUCKET: |
75be6413 |
547 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
9cec1360 |
548 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
9020ee8c |
549 | |
beac1dff |
550 | if (!$subloc) { |
551 | ## |
552 | # Hit end of list, no match |
553 | ## |
554 | return; |
555 | } |
9020ee8c |
556 | |
557 | if ( $md5 ne $key ) { |
558 | next BUCKET; |
559 | } |
560 | |
561 | ## |
562 | # Found match -- seek to offset and read signature |
563 | ## |
564 | my $signature; |
565 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
566 | read( $fh, $signature, DBM::Deep->SIG_SIZE); |
d0b74c17 |
567 | |
9020ee8c |
568 | ## |
569 | # If value is a hash or array, return new DBM::Deep object with correct offset |
570 | ## |
571 | if (($signature eq DBM::Deep->TYPE_HASH) || ($signature eq DBM::Deep->TYPE_ARRAY)) { |
572 | my $obj = DBM::Deep->new( |
573 | type => $signature, |
574 | base_offset => $subloc, |
575 | root => $obj->_root, |
576 | ); |
d0b74c17 |
577 | |
9020ee8c |
578 | if ($obj->_root->{autobless}) { |
579 | ## |
580 | # Skip over value and plain key to see if object needs |
581 | # to be re-blessed |
582 | ## |
251dfd0e |
583 | seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR); |
d0b74c17 |
584 | |
9020ee8c |
585 | my $size; |
251dfd0e |
586 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
9020ee8c |
587 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
588 | |
9020ee8c |
589 | my $bless_bit; |
590 | read( $fh, $bless_bit, 1); |
591 | if (ord($bless_bit)) { |
592 | ## |
593 | # Yes, object needs to be re-blessed |
594 | ## |
595 | my $class_name; |
251dfd0e |
596 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
9020ee8c |
597 | if ($size) { read( $fh, $class_name, $size); } |
598 | if ($class_name) { $obj = bless( $obj, $class_name ); } |
599 | } |
600 | } |
d0b74c17 |
601 | |
9020ee8c |
602 | return $obj; |
603 | } |
d0b74c17 |
604 | |
9020ee8c |
605 | ## |
606 | # Otherwise return actual value |
607 | ## |
608 | elsif ($signature eq DBM::Deep->SIG_DATA) { |
609 | my $size; |
75be6413 |
610 | read( $fh, $size, $self->{data_size}); |
611 | $size = unpack($self->{data_pack}, $size); |
612 | |
9020ee8c |
613 | my $value = ''; |
9020ee8c |
614 | if ($size) { read( $fh, $value, $size); } |
615 | return $value; |
616 | } |
d0b74c17 |
617 | |
9020ee8c |
618 | ## |
619 | # Key exists, but content is null |
620 | ## |
621 | else { return; } |
beac1dff |
622 | } # i loop |
9020ee8c |
623 | |
beac1dff |
624 | return; |
9020ee8c |
625 | } |
ab0e4957 |
626 | |
627 | sub delete_bucket { |
beac1dff |
628 | ## |
629 | # Delete single key/value pair given tag and MD5 digested key. |
630 | ## |
631 | my $self = shift; |
632 | my ($obj, $tag, $md5) = @_; |
633 | my $keys = $tag->{content}; |
ab0e4957 |
634 | |
635 | my $fh = $obj->_fh; |
d0b74c17 |
636 | |
beac1dff |
637 | ## |
638 | # Iterate through buckets, looking for a key match |
639 | ## |
ab0e4957 |
640 | BUCKET: |
beac1dff |
641 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
9cec1360 |
642 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
ab0e4957 |
643 | |
beac1dff |
644 | if (!$subloc) { |
645 | ## |
646 | # Hit end of list, no match |
647 | ## |
648 | return; |
649 | } |
ab0e4957 |
650 | |
651 | if ( $md5 ne $key ) { |
652 | next BUCKET; |
653 | } |
654 | |
655 | ## |
656 | # Matched key -- delete bucket and return |
657 | ## |
251dfd0e |
658 | seek($fh, $tag->{offset} + ($i * $self->{bucket_size}) + $obj->_root->{file_offset}, SEEK_SET); |
659 | print( $fh substr($keys, ($i+1) * $self->{bucket_size} ) ); |
660 | print( $fh chr(0) x $self->{bucket_size} ); |
d0b74c17 |
661 | |
ab0e4957 |
662 | return 1; |
beac1dff |
663 | } # i loop |
ab0e4957 |
664 | |
beac1dff |
665 | return; |
ab0e4957 |
666 | } |
667 | |
912d50b1 |
668 | sub bucket_exists { |
beac1dff |
669 | ## |
670 | # Check existence of single key given tag and MD5 digested key. |
671 | ## |
672 | my $self = shift; |
673 | my ($obj, $tag, $md5) = @_; |
674 | my $keys = $tag->{content}; |
d0b74c17 |
675 | |
beac1dff |
676 | ## |
677 | # Iterate through buckets, looking for a key match |
678 | ## |
912d50b1 |
679 | BUCKET: |
beac1dff |
680 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
9cec1360 |
681 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
912d50b1 |
682 | |
beac1dff |
683 | if (!$subloc) { |
684 | ## |
685 | # Hit end of list, no match |
686 | ## |
687 | return; |
688 | } |
912d50b1 |
689 | |
690 | if ( $md5 ne $key ) { |
691 | next BUCKET; |
692 | } |
693 | |
694 | ## |
695 | # Matched key -- return true |
696 | ## |
697 | return 1; |
beac1dff |
698 | } # i loop |
912d50b1 |
699 | |
beac1dff |
700 | return; |
912d50b1 |
701 | } |
702 | |
6736c116 |
703 | sub find_bucket_list { |
beac1dff |
704 | ## |
705 | # Locate offset for bucket list, given digested key |
706 | ## |
707 | my $self = shift; |
d0b74c17 |
708 | my ($obj, $md5, $args) = @_; |
709 | $args = {} unless $args; |
710 | |
beac1dff |
711 | ## |
712 | # Locate offset for bucket list using digest index system |
713 | ## |
e5fc7e69 |
714 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
715 | or $self->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
716 | #print $obj->_base_offset, " : $tag->{signature} : $tag->{offset} : $tag->{size}\n"; |
d0b74c17 |
717 | |
e5fc7e69 |
718 | my $ch = 0; |
beac1dff |
719 | while ($tag->{signature} ne DBM::Deep->SIG_BLIST) { |
d0b74c17 |
720 | my $num = ord substr($md5, $ch, 1); |
721 | |
722 | my $ref_loc = $tag->{offset} + ($num * $self->{long_size}); |
723 | $tag = $self->index_lookup( $obj, $tag, $num ); |
724 | |
725 | if (!$tag) { |
726 | if ( $args->{create} ) { |
727 | my $fh = $obj->_fh; |
728 | seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET); |
729 | print( $fh pack($self->{long_pack}, $obj->_root->{end}) ); |
730 | |
731 | $tag = $self->create_tag( |
732 | $obj, $obj->_root->{end}, |
733 | DBM::Deep->SIG_BLIST, |
734 | chr(0) x $self->{bucket_list_size}, |
735 | ); |
736 | |
737 | $tag->{ref_loc} = $ref_loc; |
738 | $tag->{ch} = $ch; |
739 | |
740 | last; |
741 | } |
742 | else { |
743 | return; |
744 | } |
745 | } |
746 | |
747 | $tag->{ch} = $ch; |
748 | $tag->{ref_loc} = $ref_loc; |
749 | |
beac1dff |
750 | $ch++; |
751 | } |
d0b74c17 |
752 | |
beac1dff |
753 | return $tag; |
6736c116 |
754 | } |
755 | |
d0b74c17 |
756 | sub index_lookup { |
757 | ## |
758 | # Given index tag, lookup single entry in index and return . |
759 | ## |
760 | my $self = shift; |
761 | my ($obj, $tag, $index) = @_; |
762 | |
763 | my $location = unpack( |
764 | $self->{long_pack}, |
765 | substr( |
766 | $tag->{content}, |
767 | $index * $self->{long_size}, |
768 | $self->{long_size}, |
769 | ), |
770 | ); |
771 | |
772 | if (!$location) { return; } |
773 | |
774 | return $self->load_tag( $obj, $location ); |
775 | } |
776 | |
6736c116 |
777 | sub traverse_index { |
beac1dff |
778 | ## |
779 | # Scan index and recursively step into deeper levels, looking for next key. |
780 | ## |
6736c116 |
781 | my $self = shift; |
782 | my ($obj, $offset, $ch, $force_return_next) = @_; |
d0b74c17 |
783 | |
beac1dff |
784 | my $tag = $self->load_tag($obj, $offset ); |
6736c116 |
785 | |
786 | my $fh = $obj->_fh; |
d0b74c17 |
787 | |
beac1dff |
788 | if ($tag->{signature} ne DBM::Deep->SIG_BLIST) { |
789 | my $content = $tag->{content}; |
e5fc7e69 |
790 | my $start = $obj->{return_next} ? 0 : ord(substr($obj->{prev_md5}, $ch, 1)); |
d0b74c17 |
791 | |
beac1dff |
792 | for (my $index = $start; $index < 256; $index++) { |
e5fc7e69 |
793 | my $subloc = unpack( |
794 | $self->{long_pack}, |
795 | substr($content, $index * $self->{long_size}, $self->{long_size}), |
796 | ); |
797 | |
beac1dff |
798 | if ($subloc) { |
e5fc7e69 |
799 | my $result = $self->traverse_index( |
800 | $obj, $subloc, $ch + 1, $force_return_next, |
801 | ); |
802 | |
beac1dff |
803 | if (defined($result)) { return $result; } |
804 | } |
805 | } # index loop |
d0b74c17 |
806 | |
beac1dff |
807 | $obj->{return_next} = 1; |
808 | } # tag is an index |
d0b74c17 |
809 | |
e5fc7e69 |
810 | else { |
beac1dff |
811 | my $keys = $tag->{content}; |
812 | if ($force_return_next) { $obj->{return_next} = 1; } |
d0b74c17 |
813 | |
beac1dff |
814 | ## |
815 | # Iterate through buckets, looking for a key match |
816 | ## |
817 | for (my $i=0; $i<$self->{max_buckets}; $i++) { |
9cec1360 |
818 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
d0b74c17 |
819 | |
beac1dff |
820 | if (!$subloc) { |
821 | ## |
822 | # End of bucket list -- return to outer loop |
823 | ## |
824 | $obj->{return_next} = 1; |
825 | last; |
826 | } |
827 | elsif ($key eq $obj->{prev_md5}) { |
828 | ## |
829 | # Located previous key -- return next one found |
830 | ## |
831 | $obj->{return_next} = 1; |
832 | next; |
833 | } |
834 | elsif ($obj->{return_next}) { |
835 | ## |
836 | # Seek to bucket location and skip over signature |
837 | ## |
838 | seek($fh, $subloc + DBM::Deep->SIG_SIZE + $obj->_root->{file_offset}, SEEK_SET); |
d0b74c17 |
839 | |
beac1dff |
840 | ## |
841 | # Skip over value to get to plain key |
842 | ## |
843 | my $size; |
e5fc7e69 |
844 | read( $fh, $size, $self->{data_size}); |
845 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
846 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
847 | |
beac1dff |
848 | ## |
849 | # Read in plain key and return as scalar |
850 | ## |
851 | my $plain_key; |
e5fc7e69 |
852 | read( $fh, $size, $self->{data_size}); |
853 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
854 | if ($size) { read( $fh, $plain_key, $size); } |
d0b74c17 |
855 | |
beac1dff |
856 | return $plain_key; |
857 | } |
858 | } # bucket loop |
d0b74c17 |
859 | |
beac1dff |
860 | $obj->{return_next} = 1; |
861 | } # tag is a bucket list |
d0b74c17 |
862 | |
beac1dff |
863 | return; |
6736c116 |
864 | } |
865 | |
866 | sub get_next_key { |
beac1dff |
867 | ## |
868 | # Locate next key, given digested previous one |
869 | ## |
6736c116 |
870 | my $self = shift; |
871 | my ($obj) = @_; |
d0b74c17 |
872 | |
beac1dff |
873 | $obj->{prev_md5} = $_[1] ? $_[1] : undef; |
874 | $obj->{return_next} = 0; |
d0b74c17 |
875 | |
beac1dff |
876 | ## |
877 | # If the previous key was not specifed, start at the top and |
878 | # return the first one found. |
879 | ## |
880 | if (!$obj->{prev_md5}) { |
881 | $obj->{prev_md5} = chr(0) x $self->{hash_size}; |
882 | $obj->{return_next} = 1; |
883 | } |
d0b74c17 |
884 | |
beac1dff |
885 | return $self->traverse_index( $obj, $obj->_base_offset, 0 ); |
6736c116 |
886 | } |
887 | |
75be6413 |
888 | # Utilities |
889 | |
9cec1360 |
890 | sub _get_key_subloc { |
75be6413 |
891 | my $self = shift; |
892 | my ($keys, $idx) = @_; |
893 | |
9cec1360 |
894 | my ($key, $subloc) = unpack( |
895 | "a$self->{hash_size} $self->{long_pack}", |
75be6413 |
896 | substr( |
897 | $keys, |
9cec1360 |
898 | ($idx * $self->{bucket_size}), |
899 | $self->{bucket_size}, |
75be6413 |
900 | ), |
901 | ); |
902 | |
9cec1360 |
903 | return ($key, $subloc); |
75be6413 |
904 | } |
905 | |
a20d9a3f |
906 | 1; |
907 | __END__ |