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