Commit | Line | Data |
a20d9a3f |
1 | package DBM::Deep::Engine; |
2 | |
3 | use strict; |
4 | |
5 | use Fcntl qw( :DEFAULT :flock :seek ); |
6 | |
8db25060 |
7 | ## |
8 | # Setup file and tag signatures. These should never change. |
9 | ## |
10 | sub SIG_FILE () { 'DPDB' } |
11 | sub SIG_INTERNAL () { 'i' } |
12 | sub SIG_HASH () { 'H' } |
13 | sub SIG_ARRAY () { 'A' } |
8db25060 |
14 | sub SIG_NULL () { 'N' } |
15 | sub SIG_DATA () { 'D' } |
16 | sub SIG_INDEX () { 'I' } |
17 | sub SIG_BLIST () { 'B' } |
18 | sub SIG_SIZE () { 1 } |
19 | |
612969fb |
20 | sub precalc_sizes { |
beac1dff |
21 | ## |
22 | # Precalculate index, bucket and bucket list sizes |
23 | ## |
251dfd0e |
24 | my $self = shift; |
1bf65be7 |
25 | |
251dfd0e |
26 | $self->{index_size} = (2**8) * $self->{long_size}; |
6ed2f3df |
27 | $self->{bucket_size} = $self->{hash_size} + $self->{long_size} * 2; |
251dfd0e |
28 | $self->{bucket_list_size} = $self->{max_buckets} * $self->{bucket_size}; |
1bf65be7 |
29 | |
251dfd0e |
30 | return 1; |
1bf65be7 |
31 | } |
32 | |
33 | sub set_pack { |
beac1dff |
34 | ## |
35 | # Set pack/unpack modes (see file header for more) |
36 | ## |
251dfd0e |
37 | my $self = shift; |
1bf65be7 |
38 | my ($long_s, $long_p, $data_s, $data_p) = @_; |
39 | |
81d16922 |
40 | ## |
75be6413 |
41 | # Set to 4 and 'N' for 32-bit offset tags (default). Theoretical limit of 4 |
42 | # GB per file. |
beac1dff |
43 | # (Perl must be compiled with largefile support for files > 2 GB) |
81d16922 |
44 | # |
45 | # Set to 8 and 'Q' for 64-bit offsets. Theoretical limit of 16 XB per file. |
beac1dff |
46 | # (Perl must be compiled with largefile and 64-bit long support) |
81d16922 |
47 | ## |
251dfd0e |
48 | $self->{long_size} = $long_s ? $long_s : 4; |
49 | $self->{long_pack} = $long_p ? $long_p : 'N'; |
1bf65be7 |
50 | |
81d16922 |
51 | ## |
75be6413 |
52 | # Set to 4 and 'N' for 32-bit data length prefixes. Limit of 4 GB for each |
d5d7c51d |
53 | # key/value. Upgrading this is possible (see above) but probably not |
54 | # necessary. If you need more than 4 GB for a single key or value, this |
55 | # module is really not for you :-) |
81d16922 |
56 | ## |
251dfd0e |
57 | $self->{data_size} = $data_s ? $data_s : 4; |
58 | $self->{data_pack} = $data_p ? $data_p : 'N'; |
1bf65be7 |
59 | |
beac1dff |
60 | return $self->precalc_sizes(); |
1bf65be7 |
61 | } |
62 | |
63 | sub set_digest { |
beac1dff |
64 | ## |
65 | # Set key digest function (default is MD5) |
66 | ## |
251dfd0e |
67 | my $self = shift; |
1bf65be7 |
68 | my ($digest_func, $hash_size) = @_; |
69 | |
d0b74c17 |
70 | $self->{digest} = $digest_func ? $digest_func : \&Digest::MD5::md5; |
251dfd0e |
71 | $self->{hash_size} = $hash_size ? $hash_size : 16; |
612969fb |
72 | |
beac1dff |
73 | return $self->precalc_sizes(); |
612969fb |
74 | } |
75 | |
76 | sub new { |
77 | my $class = shift; |
78 | my ($args) = @_; |
79 | |
80 | my $self = bless { |
81 | long_size => 4, |
82 | long_pack => 'N', |
83 | data_size => 4, |
84 | data_pack => 'N', |
251dfd0e |
85 | |
612969fb |
86 | digest => \&Digest::MD5::md5, |
87 | hash_size => 16, |
251dfd0e |
88 | |
81d16922 |
89 | ## |
d5d7c51d |
90 | # Maximum number of buckets per list before another level of indexing is |
91 | # done. |
92 | # Increase this value for slightly greater speed, but larger database |
93 | # files. DO NOT decrease this value below 16, due to risk of recursive |
94 | # reindex overrun. |
81d16922 |
95 | ## |
612969fb |
96 | max_buckets => 16, |
97 | }, $class; |
98 | |
251dfd0e |
99 | $self->precalc_sizes; |
612969fb |
100 | |
101 | return $self; |
1bf65be7 |
102 | } |
103 | |
70b55428 |
104 | sub setup_fh { |
105 | my $self = shift; |
106 | my ($obj) = @_; |
107 | |
108 | $self->open( $obj ) if !defined $obj->_fh; |
109 | |
6fde4ed2 |
110 | my $fh = $obj->_fh; |
111 | flock $fh, LOCK_EX; |
118ba343 |
112 | |
6fde4ed2 |
113 | unless ( $obj->{base_offset} ) { |
118ba343 |
114 | seek($fh, 0 + $obj->_root->{file_offset}, SEEK_SET); |
115 | my $signature; |
116 | my $bytes_read = read( $fh, $signature, length(SIG_FILE)); |
117 | |
118 | ## |
119 | # File is empty -- write signature and master index |
120 | ## |
121 | if (!$bytes_read) { |
c9ec091a |
122 | my $loc = $self->_request_space( $obj, length( SIG_FILE ) ); |
123 | seek($fh, $loc + $obj->_root->{file_offset}, SEEK_SET); |
118ba343 |
124 | print( $fh SIG_FILE); |
125 | |
c9ec091a |
126 | $obj->{base_offset} = $self->_request_space( |
16d1ad9b |
127 | $obj, $self->tag_size( $self->{index_size} ), |
c9ec091a |
128 | ); |
118ba343 |
129 | |
130 | $self->create_tag( |
c9ec091a |
131 | $obj, $obj->_base_offset, $obj->_type, |
f37c15ab |
132 | chr(0)x$self->{index_size}, |
118ba343 |
133 | ); |
134 | |
135 | # Flush the filehandle |
136 | my $old_fh = select $fh; |
137 | my $old_af = $|; $| = 1; $| = $old_af; |
138 | select $old_fh; |
139 | } |
140 | else { |
141 | $obj->{base_offset} = $bytes_read; |
142 | |
143 | ## |
144 | # Check signature was valid |
145 | ## |
146 | unless ($signature eq SIG_FILE) { |
147 | $self->close_fh( $obj ); |
148 | $obj->_throw_error("Signature not found -- file is not a Deep DB"); |
149 | } |
150 | |
151 | ## |
152 | # Get our type from master index signature |
153 | ## |
154 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
155 | or $obj->_throw_error("Corrupted file, no master index record"); |
156 | |
157 | unless ($obj->{type} eq $tag->{signature}) { |
158 | $obj->_throw_error("File type mismatch"); |
159 | } |
160 | } |
118ba343 |
161 | } |
e06824f8 |
162 | |
673464d9 |
163 | #XXX We have to make sure we don't mess up when autoflush isn't turned on |
70b55428 |
164 | unless ( $obj->_root->{inode} ) { |
165 | my @stats = stat($obj->_fh); |
166 | $obj->_root->{inode} = $stats[1]; |
167 | $obj->_root->{end} = $stats[7]; |
168 | } |
169 | |
6fde4ed2 |
170 | flock $fh, LOCK_UN; |
171 | |
70b55428 |
172 | return 1; |
173 | } |
174 | |
a20d9a3f |
175 | sub open { |
20f7b20c |
176 | ## |
177 | # Open a fh to the database, create if nonexistent. |
178 | # Make sure file signature matches DBM::Deep spec. |
179 | ## |
a20d9a3f |
180 | my $self = shift; |
70b55428 |
181 | my ($obj) = @_; |
a20d9a3f |
182 | |
673464d9 |
183 | # Theoretically, adding O_BINARY should remove the need for the binmode |
184 | # Of course, testing it is going to be ... interesting. |
185 | my $flags = O_RDWR | O_CREAT | O_BINARY; |
a20d9a3f |
186 | |
673464d9 |
187 | my $fh; |
d5d7c51d |
188 | my $filename = $obj->_root->{file}; |
189 | sysopen( $fh, $filename, $flags ) |
190 | or $obj->_throw_error("Cannot sysopen file '$filename': $!"); |
673464d9 |
191 | $obj->_root->{fh} = $fh; |
a20d9a3f |
192 | |
193 | #XXX Can we remove this by using the right sysopen() flags? |
194 | # Maybe ... q.v. above |
195 | binmode $fh; # for win32 |
196 | |
cd59cad8 |
197 | if ($obj->_root->{autoflush}) { |
a20d9a3f |
198 | my $old = select $fh; |
199 | $|=1; |
200 | select $old; |
201 | } |
20f7b20c |
202 | |
a20d9a3f |
203 | return 1; |
204 | } |
205 | |
3d1b8be9 |
206 | sub close_fh { |
cd59cad8 |
207 | my $self = shift; |
a21f2d90 |
208 | my ($obj) = @_; |
cd59cad8 |
209 | |
210 | if ( my $fh = $obj->_root->{fh} ) { |
211 | close $fh; |
212 | } |
213 | $obj->_root->{fh} = undef; |
214 | |
215 | return 1; |
216 | } |
217 | |
16d1ad9b |
218 | sub tag_size { |
219 | my $self = shift; |
220 | my ($size) = @_; |
221 | return SIG_SIZE + $self->{data_size} + $size; |
222 | } |
223 | |
d4b1166e |
224 | sub create_tag { |
20f7b20c |
225 | ## |
226 | # Given offset, signature and content, create tag and write to disk |
227 | ## |
d4b1166e |
228 | my $self = shift; |
20f7b20c |
229 | my ($obj, $offset, $sig, $content) = @_; |
f37c15ab |
230 | my $size = length( $content ); |
20f7b20c |
231 | |
d4b1166e |
232 | my $fh = $obj->_fh; |
233 | |
f37c15ab |
234 | if ( defined $offset ) { |
235 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
236 | } |
237 | |
251dfd0e |
238 | print( $fh $sig . pack($self->{data_pack}, $size) . $content ); |
20f7b20c |
239 | |
f37c15ab |
240 | return unless defined $offset; |
241 | |
20f7b20c |
242 | return { |
243 | signature => $sig, |
244 | size => $size, |
8db25060 |
245 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
246 | content => $content |
247 | }; |
d4b1166e |
248 | } |
249 | |
250 | sub load_tag { |
20f7b20c |
251 | ## |
252 | # Given offset, load single tag and return signature, size and data |
253 | ## |
d4b1166e |
254 | my $self = shift; |
20f7b20c |
255 | my ($obj, $offset) = @_; |
256 | |
e06824f8 |
257 | # print join(':',map{$_||''}caller(1)), $/; |
258 | |
d4b1166e |
259 | my $fh = $obj->_fh; |
260 | |
20f7b20c |
261 | seek($fh, $offset + $obj->_root->{file_offset}, SEEK_SET); |
e5fc7e69 |
262 | |
75be6413 |
263 | #XXX I'm not sure this check will work if autoflush isn't enabled ... |
e5fc7e69 |
264 | return if eof $fh; |
20f7b20c |
265 | |
d4b1166e |
266 | my $b; |
8db25060 |
267 | read( $fh, $b, SIG_SIZE + $self->{data_size} ); |
251dfd0e |
268 | my ($sig, $size) = unpack( "A $self->{data_pack}", $b ); |
20f7b20c |
269 | |
270 | my $buffer; |
271 | read( $fh, $buffer, $size); |
272 | |
273 | return { |
274 | signature => $sig, |
275 | size => $size, |
8db25060 |
276 | offset => $offset + SIG_SIZE + $self->{data_size}, |
20f7b20c |
277 | content => $buffer |
278 | }; |
d4b1166e |
279 | } |
280 | |
29b01632 |
281 | sub _length_needed { |
282 | my $self = shift; |
f37c15ab |
283 | my ($obj, $value, $key) = @_; |
29b01632 |
284 | |
285 | my $is_dbm_deep = eval { |
286 | local $SIG{'__DIE__'}; |
287 | $value->isa( 'DBM::Deep' ); |
288 | }; |
289 | |
f37c15ab |
290 | my $len = SIG_SIZE + $self->{data_size} |
291 | + $self->{data_size} + length( $key ); |
29b01632 |
292 | |
f37c15ab |
293 | if ( $is_dbm_deep && $value->_root eq $obj->_root ) { |
294 | return $len + $self->{long_size}; |
29b01632 |
295 | } |
296 | |
297 | my $r = Scalar::Util::reftype( $value ) || ''; |
9a187d8c |
298 | if ( $obj->_root->{autobless} ) { |
299 | # This is for the bit saying whether or not this thing is blessed. |
300 | $len += 1; |
301 | } |
302 | |
29b01632 |
303 | unless ( $r eq 'HASH' || $r eq 'ARRAY' ) { |
f37c15ab |
304 | if ( defined $value ) { |
305 | $len += length( $value ); |
306 | } |
307 | return $len; |
29b01632 |
308 | } |
309 | |
f37c15ab |
310 | $len += $self->{index_size}; |
29b01632 |
311 | |
312 | # if autobless is enabled, must also take into consideration |
f37c15ab |
313 | # the class name as it is stored after the key. |
29b01632 |
314 | if ( $obj->_root->{autobless} ) { |
315 | my $value_class = Scalar::Util::blessed($value); |
f37c15ab |
316 | if ( defined $value_class && !$is_dbm_deep ) { |
317 | $len += $self->{data_size} + length($value_class); |
29b01632 |
318 | } |
319 | } |
320 | |
f37c15ab |
321 | return $len; |
29b01632 |
322 | } |
323 | |
20f7b20c |
324 | sub add_bucket { |
325 | ## |
326 | # Adds one key/value pair to bucket list, given offset, MD5 digest of key, |
327 | # plain (undigested) key and value. |
328 | ## |
d4b1166e |
329 | my $self = shift; |
20f7b20c |
330 | my ($obj, $tag, $md5, $plain_key, $value) = @_; |
75be6413 |
331 | |
eea0d863 |
332 | # This verifies that only supported values will be stored. |
333 | { |
334 | my $r = Scalar::Util::reftype( $value ); |
335 | last if !defined $r; |
336 | |
337 | last if $r eq 'HASH'; |
338 | last if $r eq 'ARRAY'; |
339 | |
340 | $obj->_throw_error( |
341 | "Storage of variables of type '$r' is not supported." |
342 | ); |
343 | } |
344 | |
20f7b20c |
345 | my $location = 0; |
346 | my $result = 2; |
347 | |
348 | my $root = $obj->_root; |
f37c15ab |
349 | my $fh = $obj->_fh; |
20f7b20c |
350 | |
f37c15ab |
351 | my $actual_length = $self->_length_needed( $obj, $value, $plain_key ); |
20f7b20c |
352 | |
9a187d8c |
353 | my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 ); |
75be6413 |
354 | |
386bab6c |
355 | # Updating a known md5 |
356 | if ( $subloc ) { |
357 | $result = 1; |
20f7b20c |
358 | |
386bab6c |
359 | if ($actual_length <= $size) { |
360 | $location = $subloc; |
20f7b20c |
361 | } |
75be6413 |
362 | else { |
f37c15ab |
363 | $location = $self->_request_space( $obj, $actual_length ); |
386bab6c |
364 | seek( |
365 | $fh, |
9a187d8c |
366 | $tag->{offset} + $offset |
367 | + $self->{hash_size} + $root->{file_offset}, |
386bab6c |
368 | SEEK_SET, |
369 | ); |
9a187d8c |
370 | print( $fh pack($self->{long_pack}, $location ) ); |
371 | print( $fh pack($self->{long_pack}, $actual_length ) ); |
75be6413 |
372 | } |
75be6413 |
373 | } |
386bab6c |
374 | # Adding a new md5 |
375 | elsif ( defined $offset ) { |
f37c15ab |
376 | $location = $self->_request_space( $obj, $actual_length ); |
386bab6c |
377 | |
378 | seek( $fh, $tag->{offset} + $offset + $root->{file_offset}, SEEK_SET ); |
9a187d8c |
379 | print( $fh $md5 . pack($self->{long_pack}, $location ) ); |
380 | print( $fh pack($self->{long_pack}, $actual_length ) ); |
386bab6c |
381 | } |
382 | # If bucket didn't fit into list, split into a new index level |
383 | else { |
9a187d8c |
384 | #XXX This is going to be a problem. |
386bab6c |
385 | $self->split_index( $obj, $md5, $tag ); |
386 | |
f37c15ab |
387 | $location = $self->_request_space( $obj, $actual_length ); |
386bab6c |
388 | } |
20f7b20c |
389 | |
d5d7c51d |
390 | $self->write_value( $obj, $location, $plain_key, $value ); |
391 | |
392 | return $result; |
393 | } |
394 | |
395 | sub write_value { |
396 | my $self = shift; |
397 | my ($obj, $location, $key, $value) = @_; |
398 | |
399 | my $fh = $obj->_fh; |
400 | my $root = $obj->_root; |
401 | |
402 | my $is_dbm_deep = eval { |
403 | local $SIG{'__DIE__'}; |
404 | $value->isa( 'DBM::Deep' ); |
405 | }; |
406 | |
407 | my $internal_ref = $is_dbm_deep && ($value->_root eq $root); |
408 | |
409 | seek($fh, $location + $root->{file_offset}, SEEK_SET); |
410 | |
20f7b20c |
411 | ## |
d5d7c51d |
412 | # Write signature based on content type, set content length and write |
413 | # actual value. |
20f7b20c |
414 | ## |
d5d7c51d |
415 | my $r = Scalar::Util::reftype($value) || ''; |
d5d7c51d |
416 | if ( $internal_ref ) { |
f37c15ab |
417 | $self->create_tag( $obj, undef, SIG_INTERNAL,pack($self->{long_pack}, $value->_base_offset) ); |
418 | } |
419 | elsif ($r eq 'HASH') { |
420 | $self->create_tag( $obj, undef, SIG_HASH, chr(0)x$self->{index_size} ); |
421 | } |
422 | elsif ($r eq 'ARRAY') { |
423 | $self->create_tag( $obj, undef, SIG_ARRAY, chr(0)x$self->{index_size} ); |
424 | } |
425 | elsif (!defined($value)) { |
9a187d8c |
426 | $self->create_tag( $obj, undef, SIG_NULL, '' ); |
d5d7c51d |
427 | } |
428 | else { |
f37c15ab |
429 | $self->create_tag( $obj, undef, SIG_DATA, $value ); |
d5d7c51d |
430 | } |
20f7b20c |
431 | |
d5d7c51d |
432 | ## |
433 | # Plain key is stored AFTER value, as keys are typically fetched less often. |
434 | ## |
435 | print( $fh pack($self->{data_pack}, length($key)) . $key ); |
20f7b20c |
436 | |
9a187d8c |
437 | # Internal references don't care about autobless |
438 | return 1 if $internal_ref; |
439 | |
d5d7c51d |
440 | ## |
441 | # If value is blessed, preserve class name |
442 | ## |
443 | if ( $root->{autobless} ) { |
444 | my $value_class = Scalar::Util::blessed($value); |
f37c15ab |
445 | if ( defined $value_class && !$is_dbm_deep ) { |
d5d7c51d |
446 | print( $fh chr(1) ); |
447 | print( $fh pack($self->{data_pack}, length($value_class)) . $value_class ); |
20f7b20c |
448 | } |
d5d7c51d |
449 | else { |
450 | print( $fh chr(0) ); |
20f7b20c |
451 | } |
d5d7c51d |
452 | } |
20f7b20c |
453 | |
d5d7c51d |
454 | ## |
d5d7c51d |
455 | # If content is a hash or array, create new child DBM::Deep object and |
456 | # pass each key or element to it. |
457 | ## |
f37c15ab |
458 | if ( !$internal_ref ) { |
d5d7c51d |
459 | if ($r eq 'HASH') { |
460 | my $branch = DBM::Deep->new( |
461 | type => DBM::Deep->TYPE_HASH, |
462 | base_offset => $location, |
463 | root => $root, |
464 | ); |
465 | foreach my $key (keys %{$value}) { |
466 | $branch->STORE( $key, $value->{$key} ); |
20f7b20c |
467 | } |
d5d7c51d |
468 | } |
469 | elsif ($r eq 'ARRAY') { |
470 | my $branch = DBM::Deep->new( |
471 | type => DBM::Deep->TYPE_ARRAY, |
472 | base_offset => $location, |
473 | root => $root, |
474 | ); |
475 | my $index = 0; |
476 | foreach my $element (@{$value}) { |
477 | $branch->STORE( $index, $element ); |
478 | $index++; |
20f7b20c |
479 | } |
480 | } |
20f7b20c |
481 | } |
d4b1166e |
482 | |
d5d7c51d |
483 | return 1; |
d4b1166e |
484 | } |
485 | |
75be6413 |
486 | sub split_index { |
487 | my $self = shift; |
488 | my ($obj, $md5, $tag) = @_; |
489 | |
490 | my $fh = $obj->_fh; |
491 | my $root = $obj->_root; |
492 | my $keys = $tag->{content}; |
493 | |
494 | seek($fh, $tag->{ref_loc} + $root->{file_offset}, SEEK_SET); |
16d1ad9b |
495 | |
496 | my $loc = $self->_request_space( |
497 | $obj, $self->tag_size( $self->{index_size} ), |
498 | ); |
499 | |
500 | print( $fh pack($self->{long_pack}, $loc) ); |
75be6413 |
501 | |
502 | my $index_tag = $self->create_tag( |
16d1ad9b |
503 | $obj, $loc, SIG_INDEX, |
f37c15ab |
504 | chr(0)x$self->{index_size}, |
75be6413 |
505 | ); |
506 | |
507 | my @offsets = (); |
508 | |
9a187d8c |
509 | $keys .= $md5 . (pack($self->{long_pack}, 0) x 2); |
75be6413 |
510 | |
511 | BUCKET: |
512 | for (my $i = 0; $i <= $self->{max_buckets}; $i++) { |
9a187d8c |
513 | my ($key, $old_subloc, $size) = $self->_get_key_subloc( $keys, $i ); |
75be6413 |
514 | |
515 | next BUCKET unless $key; |
516 | |
75be6413 |
517 | my $num = ord(substr($key, $tag->{ch} + 1, 1)); |
518 | |
519 | if ($offsets[$num]) { |
8db25060 |
520 | my $offset = $offsets[$num] + SIG_SIZE + $self->{data_size}; |
75be6413 |
521 | seek($fh, $offset + $root->{file_offset}, SEEK_SET); |
522 | my $subkeys; |
523 | read( $fh, $subkeys, $self->{bucket_list_size}); |
524 | |
525 | for (my $k=0; $k<$self->{max_buckets}; $k++) { |
9cec1360 |
526 | my ($temp, $subloc) = $self->_get_key_subloc( $subkeys, $k ); |
75be6413 |
527 | |
528 | if (!$subloc) { |
529 | seek($fh, $offset + ($k * $self->{bucket_size}) + $root->{file_offset}, SEEK_SET); |
530 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
531 | last; |
532 | } |
533 | } # k loop |
534 | } |
535 | else { |
536 | $offsets[$num] = $root->{end}; |
537 | seek($fh, $index_tag->{offset} + ($num * $self->{long_size}) + $root->{file_offset}, SEEK_SET); |
75be6413 |
538 | |
2603d86e |
539 | my $loc = $self->_request_space( |
540 | $obj, $self->tag_size( $self->{bucket_list_size} ), |
541 | ); |
542 | |
543 | print( $fh pack($self->{long_pack}, $loc) ); |
544 | |
545 | my $blist_tag = $self->create_tag( |
546 | $obj, $loc, SIG_BLIST, |
f37c15ab |
547 | chr(0)x$self->{bucket_list_size}, |
2603d86e |
548 | ); |
75be6413 |
549 | |
550 | seek($fh, $blist_tag->{offset} + $root->{file_offset}, SEEK_SET); |
551 | print( $fh $key . pack($self->{long_pack}, $old_subloc || $root->{end}) ); |
552 | } |
553 | } # i loop |
554 | |
555 | return; |
556 | } |
557 | |
8db25060 |
558 | sub read_from_loc { |
559 | my $self = shift; |
560 | my ($obj, $subloc) = @_; |
561 | |
562 | my $fh = $obj->_fh; |
563 | |
564 | ## |
565 | # Found match -- seek to offset and read signature |
566 | ## |
567 | my $signature; |
568 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
569 | read( $fh, $signature, SIG_SIZE); |
570 | |
571 | ## |
572 | # If value is a hash or array, return new DBM::Deep object with correct offset |
573 | ## |
574 | if (($signature eq SIG_HASH) || ($signature eq SIG_ARRAY)) { |
575 | my $obj = DBM::Deep->new( |
576 | type => $signature, |
577 | base_offset => $subloc, |
578 | root => $obj->_root, |
579 | ); |
580 | |
581 | if ($obj->_root->{autobless}) { |
582 | ## |
583 | # Skip over value and plain key to see if object needs |
584 | # to be re-blessed |
585 | ## |
586 | seek($fh, $self->{data_size} + $self->{index_size}, SEEK_CUR); |
587 | |
588 | my $size; |
589 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
590 | if ($size) { seek($fh, $size, SEEK_CUR); } |
591 | |
592 | my $bless_bit; |
593 | read( $fh, $bless_bit, 1); |
594 | if (ord($bless_bit)) { |
595 | ## |
596 | # Yes, object needs to be re-blessed |
597 | ## |
598 | my $class_name; |
599 | read( $fh, $size, $self->{data_size}); $size = unpack($self->{data_pack}, $size); |
600 | if ($size) { read( $fh, $class_name, $size); } |
601 | if ($class_name) { $obj = bless( $obj, $class_name ); } |
602 | } |
603 | } |
604 | |
605 | return $obj; |
606 | } |
607 | elsif ( $signature eq SIG_INTERNAL ) { |
608 | my $size; |
609 | read( $fh, $size, $self->{data_size}); |
610 | $size = unpack($self->{data_pack}, $size); |
611 | |
612 | if ( $size ) { |
613 | my $new_loc; |
614 | read( $fh, $new_loc, $size ); |
615 | $new_loc = unpack( $self->{long_pack}, $new_loc ); |
616 | |
617 | return $self->read_from_loc( $obj, $new_loc ); |
618 | } |
619 | else { |
620 | return; |
621 | } |
622 | } |
623 | ## |
624 | # Otherwise return actual value |
625 | ## |
626 | elsif ($signature eq SIG_DATA) { |
627 | my $size; |
628 | read( $fh, $size, $self->{data_size}); |
629 | $size = unpack($self->{data_pack}, $size); |
630 | |
631 | my $value = ''; |
632 | if ($size) { read( $fh, $value, $size); } |
633 | return $value; |
634 | } |
635 | |
636 | ## |
637 | # Key exists, but content is null |
638 | ## |
639 | return; |
640 | } |
641 | |
9020ee8c |
642 | sub get_bucket_value { |
beac1dff |
643 | ## |
644 | # Fetch single value given tag and MD5 digested key. |
645 | ## |
646 | my $self = shift; |
647 | my ($obj, $tag, $md5) = @_; |
9020ee8c |
648 | |
9a187d8c |
649 | my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 ); |
386bab6c |
650 | if ( $subloc ) { |
8db25060 |
651 | return $self->read_from_loc( $obj, $subloc ); |
386bab6c |
652 | } |
beac1dff |
653 | return; |
9020ee8c |
654 | } |
ab0e4957 |
655 | |
656 | sub delete_bucket { |
beac1dff |
657 | ## |
658 | # Delete single key/value pair given tag and MD5 digested key. |
659 | ## |
660 | my $self = shift; |
661 | my ($obj, $tag, $md5) = @_; |
ab0e4957 |
662 | |
9a187d8c |
663 | my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 ); |
386bab6c |
664 | if ( $subloc ) { |
665 | my $fh = $obj->_fh; |
666 | seek($fh, $tag->{offset} + $offset + $obj->_root->{file_offset}, SEEK_SET); |
667 | print( $fh substr($tag->{content}, $offset + $self->{bucket_size} ) ); |
251dfd0e |
668 | print( $fh chr(0) x $self->{bucket_size} ); |
d0b74c17 |
669 | |
ab0e4957 |
670 | return 1; |
386bab6c |
671 | } |
beac1dff |
672 | return; |
ab0e4957 |
673 | } |
674 | |
912d50b1 |
675 | sub bucket_exists { |
beac1dff |
676 | ## |
677 | # Check existence of single key given tag and MD5 digested key. |
678 | ## |
679 | my $self = shift; |
680 | my ($obj, $tag, $md5) = @_; |
912d50b1 |
681 | |
9a187d8c |
682 | my ($subloc, $offset, $size) = $self->_find_in_buckets( $tag, $md5 ); |
d5d7c51d |
683 | return $subloc && 1; |
912d50b1 |
684 | } |
685 | |
6736c116 |
686 | sub find_bucket_list { |
beac1dff |
687 | ## |
688 | # Locate offset for bucket list, given digested key |
689 | ## |
690 | my $self = shift; |
d0b74c17 |
691 | my ($obj, $md5, $args) = @_; |
692 | $args = {} unless $args; |
693 | |
beac1dff |
694 | ## |
695 | # Locate offset for bucket list using digest index system |
696 | ## |
e5fc7e69 |
697 | my $tag = $self->load_tag($obj, $obj->_base_offset) |
d5d7c51d |
698 | or $obj->_throw_error( "INTERNAL ERROR - Cannot find tag" ); |
d0b74c17 |
699 | |
e5fc7e69 |
700 | my $ch = 0; |
8db25060 |
701 | while ($tag->{signature} ne SIG_BLIST) { |
d0b74c17 |
702 | my $num = ord substr($md5, $ch, 1); |
703 | |
704 | my $ref_loc = $tag->{offset} + ($num * $self->{long_size}); |
705 | $tag = $self->index_lookup( $obj, $tag, $num ); |
706 | |
707 | if (!$tag) { |
29b01632 |
708 | return if !$args->{create}; |
d0b74c17 |
709 | |
d5d7c51d |
710 | my $fh = $obj->_fh; |
711 | seek($fh, $ref_loc + $obj->_root->{file_offset}, SEEK_SET); |
16d1ad9b |
712 | |
713 | my $loc = $self->_request_space( |
714 | $obj, $self->tag_size( $self->{bucket_list_size} ), |
715 | ); |
716 | |
717 | print( $fh pack($self->{long_pack}, $loc) ); |
d0b74c17 |
718 | |
d5d7c51d |
719 | $tag = $self->create_tag( |
16d1ad9b |
720 | $obj, $loc, SIG_BLIST, |
f37c15ab |
721 | chr(0)x$self->{bucket_list_size}, |
d5d7c51d |
722 | ); |
723 | |
724 | $tag->{ref_loc} = $ref_loc; |
725 | $tag->{ch} = $ch; |
726 | |
727 | last; |
d0b74c17 |
728 | } |
729 | |
16d1ad9b |
730 | $tag->{ch} = $ch++; |
d0b74c17 |
731 | $tag->{ref_loc} = $ref_loc; |
beac1dff |
732 | } |
d0b74c17 |
733 | |
beac1dff |
734 | return $tag; |
6736c116 |
735 | } |
736 | |
d0b74c17 |
737 | sub index_lookup { |
738 | ## |
739 | # Given index tag, lookup single entry in index and return . |
740 | ## |
741 | my $self = shift; |
742 | my ($obj, $tag, $index) = @_; |
743 | |
744 | my $location = unpack( |
745 | $self->{long_pack}, |
746 | substr( |
747 | $tag->{content}, |
748 | $index * $self->{long_size}, |
749 | $self->{long_size}, |
750 | ), |
751 | ); |
752 | |
753 | if (!$location) { return; } |
754 | |
755 | return $self->load_tag( $obj, $location ); |
756 | } |
757 | |
6736c116 |
758 | sub traverse_index { |
beac1dff |
759 | ## |
760 | # Scan index and recursively step into deeper levels, looking for next key. |
761 | ## |
6736c116 |
762 | my $self = shift; |
763 | my ($obj, $offset, $ch, $force_return_next) = @_; |
d0b74c17 |
764 | |
beac1dff |
765 | my $tag = $self->load_tag($obj, $offset ); |
6736c116 |
766 | |
767 | my $fh = $obj->_fh; |
d0b74c17 |
768 | |
8db25060 |
769 | if ($tag->{signature} ne SIG_BLIST) { |
beac1dff |
770 | my $content = $tag->{content}; |
e5fc7e69 |
771 | my $start = $obj->{return_next} ? 0 : ord(substr($obj->{prev_md5}, $ch, 1)); |
d0b74c17 |
772 | |
d5d7c51d |
773 | for (my $idx = $start; $idx < (2**8); $idx++) { |
e5fc7e69 |
774 | my $subloc = unpack( |
775 | $self->{long_pack}, |
e06824f8 |
776 | substr( |
777 | $content, |
778 | $idx * $self->{long_size}, |
779 | $self->{long_size}, |
780 | ), |
e5fc7e69 |
781 | ); |
782 | |
beac1dff |
783 | if ($subloc) { |
e5fc7e69 |
784 | my $result = $self->traverse_index( |
785 | $obj, $subloc, $ch + 1, $force_return_next, |
786 | ); |
787 | |
beac1dff |
788 | if (defined($result)) { return $result; } |
789 | } |
790 | } # index loop |
d0b74c17 |
791 | |
beac1dff |
792 | $obj->{return_next} = 1; |
793 | } # tag is an index |
d0b74c17 |
794 | |
e5fc7e69 |
795 | else { |
beac1dff |
796 | my $keys = $tag->{content}; |
797 | if ($force_return_next) { $obj->{return_next} = 1; } |
d0b74c17 |
798 | |
beac1dff |
799 | ## |
800 | # Iterate through buckets, looking for a key match |
801 | ## |
8db25060 |
802 | for (my $i = 0; $i < $self->{max_buckets}; $i++) { |
9cec1360 |
803 | my ($key, $subloc) = $self->_get_key_subloc( $keys, $i ); |
d0b74c17 |
804 | |
8db25060 |
805 | # End of bucket list -- return to outer loop |
beac1dff |
806 | if (!$subloc) { |
beac1dff |
807 | $obj->{return_next} = 1; |
808 | last; |
809 | } |
8db25060 |
810 | # Located previous key -- return next one found |
beac1dff |
811 | elsif ($key eq $obj->{prev_md5}) { |
beac1dff |
812 | $obj->{return_next} = 1; |
813 | next; |
814 | } |
8db25060 |
815 | # Seek to bucket location and skip over signature |
beac1dff |
816 | elsif ($obj->{return_next}) { |
8db25060 |
817 | seek($fh, $subloc + $obj->_root->{file_offset}, SEEK_SET); |
d0b74c17 |
818 | |
beac1dff |
819 | # Skip over value to get to plain key |
8db25060 |
820 | my $sig; |
821 | read( $fh, $sig, SIG_SIZE ); |
822 | |
beac1dff |
823 | my $size; |
e5fc7e69 |
824 | read( $fh, $size, $self->{data_size}); |
825 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
826 | if ($size) { seek($fh, $size, SEEK_CUR); } |
d0b74c17 |
827 | |
beac1dff |
828 | # Read in plain key and return as scalar |
beac1dff |
829 | my $plain_key; |
e5fc7e69 |
830 | read( $fh, $size, $self->{data_size}); |
831 | $size = unpack($self->{data_pack}, $size); |
beac1dff |
832 | if ($size) { read( $fh, $plain_key, $size); } |
d0b74c17 |
833 | |
beac1dff |
834 | return $plain_key; |
835 | } |
8db25060 |
836 | } |
d0b74c17 |
837 | |
beac1dff |
838 | $obj->{return_next} = 1; |
839 | } # tag is a bucket list |
d0b74c17 |
840 | |
beac1dff |
841 | return; |
6736c116 |
842 | } |
843 | |
844 | sub get_next_key { |
beac1dff |
845 | ## |
846 | # Locate next key, given digested previous one |
847 | ## |
6736c116 |
848 | my $self = shift; |
849 | my ($obj) = @_; |
d0b74c17 |
850 | |
beac1dff |
851 | $obj->{prev_md5} = $_[1] ? $_[1] : undef; |
852 | $obj->{return_next} = 0; |
d0b74c17 |
853 | |
beac1dff |
854 | ## |
855 | # If the previous key was not specifed, start at the top and |
856 | # return the first one found. |
857 | ## |
858 | if (!$obj->{prev_md5}) { |
859 | $obj->{prev_md5} = chr(0) x $self->{hash_size}; |
860 | $obj->{return_next} = 1; |
861 | } |
d0b74c17 |
862 | |
beac1dff |
863 | return $self->traverse_index( $obj, $obj->_base_offset, 0 ); |
6736c116 |
864 | } |
865 | |
75be6413 |
866 | # Utilities |
867 | |
9cec1360 |
868 | sub _get_key_subloc { |
75be6413 |
869 | my $self = shift; |
870 | my ($keys, $idx) = @_; |
871 | |
6ed2f3df |
872 | my ($key, $subloc, $size) = unpack( |
873 | "a$self->{hash_size} $self->{long_pack} $self->{long_pack}", |
75be6413 |
874 | substr( |
875 | $keys, |
9cec1360 |
876 | ($idx * $self->{bucket_size}), |
877 | $self->{bucket_size}, |
75be6413 |
878 | ), |
879 | ); |
880 | |
6ed2f3df |
881 | return ($key, $subloc, $size); |
75be6413 |
882 | } |
883 | |
d608b06e |
884 | sub _find_in_buckets { |
885 | my $self = shift; |
886 | my ($tag, $md5) = @_; |
887 | |
888 | BUCKET: |
889 | for ( my $i = 0; $i < $self->{max_buckets}; $i++ ) { |
9a187d8c |
890 | my ($key, $subloc, $size) = $self->_get_key_subloc( |
891 | $tag->{content}, $i, |
892 | ); |
d608b06e |
893 | |
9a187d8c |
894 | return ($subloc, $i * $self->{bucket_size}, $size) unless $subloc; |
d608b06e |
895 | |
896 | next BUCKET if $key ne $md5; |
897 | |
9a187d8c |
898 | return ($subloc, $i * $self->{bucket_size}, $size); |
d608b06e |
899 | } |
900 | |
901 | return; |
902 | } |
903 | |
994ccd8e |
904 | sub _request_space { |
905 | my $self = shift; |
906 | my ($obj, $size) = @_; |
907 | |
908 | my $loc = $obj->_root->{end}; |
c9ec091a |
909 | $obj->_root->{end} += $size; |
994ccd8e |
910 | |
911 | return $loc; |
912 | } |
913 | |
914 | sub _release_space { |
915 | my $self = shift; |
916 | my ($obj, $size, $loc) = @_; |
917 | |
918 | return; |
919 | } |
920 | |
a20d9a3f |
921 | 1; |
922 | __END__ |
d5d7c51d |
923 | |
924 | # This will be added in later, after more refactoring is done. This is an early |
925 | # attempt at refactoring on the physical level instead of the virtual level. |
926 | sub _read_at { |
927 | my $self = shift; |
928 | my ($obj, $spot, $amount, $unpack) = @_; |
929 | |
930 | my $fh = $obj->_fh; |
931 | seek( $fh, $spot + $obj->_root->{file_offset}, SEEK_SET ); |
932 | |
933 | my $buffer; |
934 | my $bytes_read = read( $fh, $buffer, $amount ); |
935 | |
936 | if ( $unpack ) { |
937 | $buffer = unpack( $unpack, $buffer ); |
938 | } |
939 | |
940 | if ( wantarray ) { |
941 | return ($buffer, $bytes_read); |
942 | } |
943 | else { |
944 | return $buffer; |
945 | } |
946 | } |