1 |
package Biblio::Isis; |
2 |
use strict; |
3 |
|
4 |
use Carp; |
5 |
use File::Glob qw(:globally :nocase); |
6 |
|
7 |
BEGIN { |
8 |
use Exporter (); |
9 |
use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS); |
10 |
$VERSION = 0.22_2; |
11 |
@ISA = qw (Exporter); |
12 |
#Give a hoot don't pollute, do not export more than needed by default |
13 |
@EXPORT = qw (); |
14 |
@EXPORT_OK = qw (); |
15 |
%EXPORT_TAGS = (); |
16 |
|
17 |
} |
18 |
|
19 |
=head1 NAME |
20 |
|
21 |
Biblio::Isis - Read CDS/ISIS, WinISIS and IsisMarc database |
22 |
|
23 |
=head1 SYNOPSIS |
24 |
|
25 |
use Biblio::Isis; |
26 |
|
27 |
my $isis = new Biblio::Isis( |
28 |
isisdb => './cds/cds', |
29 |
); |
30 |
|
31 |
for(my $mfn = 1; $mfn <= $isis->count; $mfn++) { |
32 |
print $isis->to_ascii($mfn),"\n"; |
33 |
} |
34 |
|
35 |
=head1 DESCRIPTION |
36 |
|
37 |
This module will read ISIS databases created by DOS CDS/ISIS, WinIsis or |
38 |
IsisMarc. It can be used as perl-only alternative to OpenIsis module which |
39 |
seems to depriciate it's old C<XS> bindings for perl. |
40 |
|
41 |
It can create hash values from data in ISIS database (using C<to_hash>), |
42 |
ASCII dump (using C<to_ascii>) or just hash with field names and packed |
43 |
values (like C<^asomething^belse>). |
44 |
|
45 |
Unique feature of this module is ability to C<include_deleted> records. |
46 |
It will also skip zero sized fields (OpenIsis has a bug in XS bindings, so |
47 |
fields which are zero sized will be filled with random junk from memory). |
48 |
|
49 |
It also has support for identifiers (only if ISIS database is created by |
50 |
IsisMarc), see C<to_hash>. |
51 |
|
52 |
This module will always be slower than OpenIsis module which use C |
53 |
library. However, since it's written in perl, it's platform independent (so |
54 |
you don't need C compiler), and can be easily modified. I hope that it |
55 |
creates data structures which are easier to use than ones created by |
56 |
OpenIsis, so reduced time in other parts of the code should compensate for |
57 |
slower performance of this module (speed of reading ISIS database is |
58 |
rarely an issue). |
59 |
|
60 |
=head1 METHODS |
61 |
|
62 |
=cut |
63 |
|
64 |
# my $ORDN; # Nodes Order |
65 |
# my $ORDF; # Leafs Order |
66 |
# my $N; # Number of Memory buffers for nodes |
67 |
# my $K; # Number of buffers for first level index |
68 |
# my $LIV; # Current number of Index Levels |
69 |
# my $POSRX; # Pointer to Root Record in N0x |
70 |
# my $NMAXPOS; # Next Available position in N0x |
71 |
# my $FMAXPOS; # Next available position in L0x |
72 |
# my $ABNORMAL; # Formal BTree normality indicator |
73 |
|
74 |
# |
75 |
# some binary reads |
76 |
# |
77 |
|
78 |
=head2 new |
79 |
|
80 |
Open ISIS database |
81 |
|
82 |
my $isis = new Biblio::Isis( |
83 |
isisdb => './cds/cds', |
84 |
read_fdt => 1, |
85 |
include_deleted => 1, |
86 |
hash_filter => sub { |
87 |
my ($v,$field_number) = @_; |
88 |
$v =~ s#foo#bar#g; |
89 |
}, |
90 |
debug => 1, |
91 |
join_subfields_with => ' ; ', |
92 |
); |
93 |
|
94 |
Options are described below: |
95 |
|
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=over 5 |
97 |
|
98 |
=item isisdb |
99 |
|
100 |
This is full or relative path to ISIS database files which include |
101 |
common prefix of C<.MST>, and C<.XRF> and optionally C<.FDT> (if using |
102 |
C<read_fdt> option) files. |
103 |
|
104 |
In this example it uses C<./cds/cds.MST> and related files. |
105 |
|
106 |
=item read_fdt |
107 |
|
108 |
Boolean flag to specify if field definition table should be read. It's off |
109 |
by default. |
110 |
|
111 |
=item include_deleted |
112 |
|
113 |
Don't skip logically deleted records in ISIS. |
114 |
|
115 |
=item hash_filter |
116 |
|
117 |
Filter code ref which will be used before data is converted to hash. |
118 |
|
119 |
=item debug |
120 |
|
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Dump a B<lot> of debugging output even at level 1. For even more increase level. |
122 |
|
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=item join_subfields_with |
124 |
|
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Define delimiter which will be used to join repeatable subfields. This |
126 |
option is included to support lagacy application written against version |
127 |
older than 0.21 of this module. By default, it disabled. See L</to_hash>. |
128 |
|
129 |
=back |
130 |
|
131 |
=cut |
132 |
|
133 |
sub new { |
134 |
my $class = shift; |
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my $self = {}; |
136 |
bless($self, $class); |
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|
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croak "new needs database name (isisdb) as argument!" unless ({@_}->{isisdb}); |
139 |
|
140 |
foreach my $v (qw{isisdb debug include_deleted hash_filter}) { |
141 |
$self->{$v} = {@_}->{$v}; |
142 |
} |
143 |
|
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my @isis_files = grep(/\.(FDT|MST|XRF|CNT)$/i,glob($self->{isisdb}."*")); |
145 |
|
146 |
foreach my $f (@isis_files) { |
147 |
my $ext = $1 if ($f =~ m/\.(\w\w\w)$/); |
148 |
$self->{lc($ext)."_file"} = $f; |
149 |
} |
150 |
|
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my @must_exist = qw(mst xrf); |
152 |
push @must_exist, "fdt" if ($self->{read_fdt}); |
153 |
|
154 |
foreach my $ext (@must_exist) { |
155 |
unless ($self->{$ext."_file"}) { |
156 |
carp "missing ",uc($ext)," file in ",$self->{isisdb}; |
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return; |
158 |
} |
159 |
} |
160 |
|
161 |
if ($self->{debug}) { |
162 |
print STDERR "## using files: ",join(" ",@isis_files),"\n"; |
163 |
eval "use Data::Dump"; |
164 |
|
165 |
if (! $@) { |
166 |
*Dumper = *Data::Dump::dump; |
167 |
} else { |
168 |
use Data::Dumper; |
169 |
} |
170 |
} |
171 |
|
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# if you want to read .FDT file use read_fdt argument when creating class! |
173 |
if ($self->{read_fdt} && -e $self->{fdt_file}) { |
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|
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# read the $db.FDT file for tags |
176 |
my $fieldzone=0; |
177 |
|
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open(my $fileFDT, $self->{fdt_file}) || croak "can't read '$self->{fdt_file}': $!"; |
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binmode($fileFDT); |
180 |
|
181 |
while (<$fileFDT>) { |
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chomp; |
183 |
if ($fieldzone) { |
184 |
my $name=substr($_,0,30); |
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my $tag=substr($_,50,3); |
186 |
|
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$name =~ s/\s+$//; |
188 |
$tag =~ s/\s+$//; |
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|
190 |
$self->{'TagName'}->{$tag}=$name; |
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} |
192 |
|
193 |
if (/^\*\*\*/) { |
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$fieldzone=1; |
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} |
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} |
197 |
|
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close($fileFDT); |
199 |
} |
200 |
|
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# Get the Maximum MFN from $db.MST |
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|
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open($self->{'fileMST'}, $self->{mst_file}) || croak "can't open '$self->{mst_file}': $!"; |
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binmode($self->{'fileMST'}); |
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|
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# MST format: (* = 32 bit signed) |
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# CTLMFN* always 0 |
208 |
# NXTMFN* MFN to be assigned to the next record created |
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# NXTMFB* last block allocated to master file |
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# NXTMFP offset to next available position in last block |
211 |
# MFTYPE always 0 for user db file (1 for system) |
212 |
seek($self->{'fileMST'},4,0) || croak "can't seek to offset 0 in MST: $!"; |
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|
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my $buff; |
215 |
|
216 |
read($self->{'fileMST'}, $buff, 4) || croak "can't read NXTMFN from MST: $!"; |
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$self->{'NXTMFN'}=unpack("V",$buff) || croak "NXTNFN is zero"; |
218 |
|
219 |
print STDERR "## self ",Dumper($self),"\n" if ($self->{debug}); |
220 |
|
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# open files for later |
222 |
open($self->{'fileXRF'}, $self->{xrf_file}) || croak "can't open '$self->{xrf_file}': $!"; |
223 |
binmode($self->{'fileXRF'}); |
224 |
|
225 |
$self ? return $self : return undef; |
226 |
} |
227 |
|
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=head2 count |
229 |
|
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Return number of records in database |
231 |
|
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print $isis->count; |
233 |
|
234 |
=cut |
235 |
|
236 |
sub count { |
237 |
my $self = shift; |
238 |
return $self->{'NXTMFN'} - 1; |
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} |
240 |
|
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=head2 fetch |
242 |
|
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Read record with selected MFN |
244 |
|
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my $rec = $isis->fetch(55); |
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|
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Returns hash with keys which are field names and values are unpacked values |
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for that field like this: |
249 |
|
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$rec = { |
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'210' => [ '^aNew York^cNew York University press^dcop. 1988' ], |
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'990' => [ '2140', '88', 'HAY' ], |
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}; |
254 |
|
255 |
=cut |
256 |
|
257 |
sub fetch { |
258 |
my $self = shift; |
259 |
|
260 |
my $mfn = shift || croak "fetch needs MFN as argument!"; |
261 |
|
262 |
# is mfn allready in memory? |
263 |
my $old_mfn = $self->{'current_mfn'} || -1; |
264 |
return $self->{record} if ($mfn == $old_mfn); |
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|
266 |
print STDERR "## fetch: $mfn\n" if ($self->{debug}); |
267 |
|
268 |
# XXX check this? |
269 |
my $mfnpos=($mfn+int(($mfn-1)/127))*4; |
270 |
|
271 |
print STDERR "## seeking to $mfnpos in file '$self->{xrf_file}'\n" if ($self->{debug}); |
272 |
seek($self->{'fileXRF'},$mfnpos,0); |
273 |
|
274 |
my $buff; |
275 |
|
276 |
# delete old record |
277 |
delete $self->{record}; |
278 |
|
279 |
# read XRFMFB abd XRFMFP |
280 |
read($self->{'fileXRF'}, $buff, 4); |
281 |
my $pointer=unpack("V",$buff); |
282 |
if (! $pointer) { |
283 |
if ($self->{include_deleted}) { |
284 |
return; |
285 |
} else { |
286 |
warn "pointer for MFN $mfn is null\n"; |
287 |
return; |
288 |
} |
289 |
} |
290 |
|
291 |
# check for logically deleted record |
292 |
if ($pointer & 0x80000000) { |
293 |
print STDERR "## record $mfn is logically deleted\n" if ($self->{debug}); |
294 |
$self->{deleted} = $mfn; |
295 |
|
296 |
return unless $self->{include_deleted}; |
297 |
|
298 |
# abs |
299 |
$pointer = ($pointer ^ 0xffffffff) + 1; |
300 |
} |
301 |
|
302 |
my $XRFMFB = int($pointer/2048); |
303 |
my $XRFMFP = $pointer - ($XRFMFB*2048); |
304 |
|
305 |
# (XRFMFB - 1) * 512 + XRFMFP |
306 |
# why do i have to do XRFMFP % 1024 ? |
307 |
|
308 |
my $blk_off = (($XRFMFB - 1) * 512) + ($XRFMFP % 512); |
309 |
|
310 |
print STDERR "## pointer: $pointer XRFMFB: $XRFMFB XRFMFP: $XRFMFP offset: $blk_off\n" if ($self->{'debug'}); |
311 |
|
312 |
# Get Record Information |
313 |
|
314 |
seek($self->{'fileMST'},$blk_off,0) || croak "can't seek to $blk_off: $!"; |
315 |
|
316 |
read($self->{'fileMST'}, $buff, 4) || croak "can't read 4 bytes at offset $blk_off from MST file: $!"; |
317 |
my $value=unpack("V",$buff); |
318 |
|
319 |
print STDERR "## offset for rowid $value is $blk_off (blk $XRFMFB off $XRFMFP)\n" if ($self->{debug}); |
320 |
|
321 |
if ($value!=$mfn) { |
322 |
if ($value == 0) { |
323 |
print STDERR "## record $mfn is physically deleted\n" if ($self->{debug}); |
324 |
$self->{deleted} = $mfn; |
325 |
return; |
326 |
} |
327 |
|
328 |
carp "Error: MFN ".$mfn." not found in MST file, found $value"; |
329 |
return; |
330 |
} |
331 |
|
332 |
read($self->{'fileMST'}, $buff, 14); |
333 |
|
334 |
my ($MFRL,$MFBWB,$MFBWP,$BASE,$NVF,$STATUS) = unpack("vVvvvv", $buff); |
335 |
|
336 |
print STDERR "## MFRL: $MFRL MFBWB: $MFBWB MFBWP: $MFBWP BASE: $BASE NVF: $NVF STATUS: $STATUS\n" if ($self->{debug}); |
337 |
|
338 |
warn "MFRL $MFRL is not even number" unless ($MFRL % 2 == 0); |
339 |
|
340 |
warn "BASE is not 18+6*NVF" unless ($BASE == 18 + 6 * $NVF); |
341 |
|
342 |
# Get Directory Format |
343 |
|
344 |
my @FieldPOS; |
345 |
my @FieldLEN; |
346 |
my @FieldTAG; |
347 |
|
348 |
read($self->{'fileMST'}, $buff, 6 * $NVF); |
349 |
|
350 |
my $rec_len = 0; |
351 |
|
352 |
for (my $i = 0 ; $i < $NVF ; $i++) { |
353 |
|
354 |
my ($TAG,$POS,$LEN) = unpack("vvv", substr($buff,$i * 6, 6)); |
355 |
|
356 |
print STDERR "## TAG: $TAG POS: $POS LEN: $LEN\n" if ($self->{debug}); |
357 |
|
358 |
# The TAG does not exists in .FDT so we set it to 0. |
359 |
# |
360 |
# XXX This is removed from perl version; .FDT file is updated manually, so |
361 |
# you will often have fields in .MST file which aren't in .FDT. On the other |
362 |
# hand, IsisMarc doesn't use .FDT files at all! |
363 |
|
364 |
#if (! $self->{TagName}->{$TAG}) { |
365 |
# $TAG=0; |
366 |
#} |
367 |
|
368 |
push @FieldTAG,$TAG; |
369 |
push @FieldPOS,$POS; |
370 |
push @FieldLEN,$LEN; |
371 |
|
372 |
$rec_len += $LEN; |
373 |
} |
374 |
|
375 |
# Get Variable Fields |
376 |
|
377 |
read($self->{'fileMST'},$buff,$rec_len); |
378 |
|
379 |
print STDERR "## rec_len: $rec_len poc: ",tell($self->{'fileMST'})."\n" if ($self->{debug}); |
380 |
|
381 |
for (my $i = 0 ; $i < $NVF ; $i++) { |
382 |
# skip zero-sized fields |
383 |
next if ($FieldLEN[$i] == 0); |
384 |
|
385 |
push @{$self->{record}->{$FieldTAG[$i]}}, substr($buff,$FieldPOS[$i],$FieldLEN[$i]); |
386 |
} |
387 |
|
388 |
$self->{'current_mfn'} = $mfn; |
389 |
|
390 |
print STDERR Dumper($self),"\n" if ($self->{debug}); |
391 |
|
392 |
return $self->{'record'}; |
393 |
} |
394 |
|
395 |
=head2 mfn |
396 |
|
397 |
Returns current MFN position |
398 |
|
399 |
my $mfn = $isis->mfn; |
400 |
|
401 |
=cut |
402 |
|
403 |
# This function should be simple return $self->{current_mfn}, |
404 |
# but if new is called with _hack_mfn it becomes setter. |
405 |
# It's useful in tests when setting $isis->{record} directly |
406 |
|
407 |
sub mfn { |
408 |
my $self = shift; |
409 |
return $self->{current_mfn}; |
410 |
}; |
411 |
|
412 |
|
413 |
=head2 to_ascii |
414 |
|
415 |
Returns ASCII output of record with specified MFN |
416 |
|
417 |
print $isis->to_ascii(42); |
418 |
|
419 |
This outputs something like this: |
420 |
|
421 |
210 ^aNew York^cNew York University press^dcop. 1988 |
422 |
990 2140 |
423 |
990 88 |
424 |
990 HAY |
425 |
|
426 |
If C<read_fdt> is specified when calling C<new> it will display field names |
427 |
from C<.FDT> file instead of numeric tags. |
428 |
|
429 |
=cut |
430 |
|
431 |
sub to_ascii { |
432 |
my $self = shift; |
433 |
|
434 |
my $mfn = shift || croak "need MFN"; |
435 |
|
436 |
my $rec = $self->fetch($mfn) || return; |
437 |
|
438 |
my $out = "0\t$mfn"; |
439 |
|
440 |
foreach my $f (sort keys %{$rec}) { |
441 |
my $fn = $self->tag_name($f); |
442 |
$out .= "\n$fn\t".join("\n$fn\t",@{$self->{record}->{$f}}); |
443 |
} |
444 |
|
445 |
$out .= "\n"; |
446 |
|
447 |
return $out; |
448 |
} |
449 |
|
450 |
=head2 to_hash |
451 |
|
452 |
Read record with specified MFN and convert it to hash |
453 |
|
454 |
my $hash = $isis->to_hash($mfn); |
455 |
|
456 |
It has ability to convert characters (using C<hash_filter>) from ISIS |
457 |
database before creating structures enabling character re-mapping or quick |
458 |
fix-up of data. |
459 |
|
460 |
This function returns hash which is like this: |
461 |
|
462 |
$hash = { |
463 |
'210' => [ |
464 |
{ |
465 |
'c' => 'New York University press', |
466 |
'a' => 'New York', |
467 |
'd' => 'cop. 1988' |
468 |
} |
469 |
], |
470 |
'990' => [ |
471 |
'2140', |
472 |
'88', |
473 |
'HAY' |
474 |
], |
475 |
}; |
476 |
|
477 |
You can later use that hash to produce any output from ISIS data. |
478 |
|
479 |
If database is created using IsisMarc, it will also have to special fields |
480 |
which will be used for identifiers, C<i1> and C<i2> like this: |
481 |
|
482 |
'200' => [ |
483 |
{ |
484 |
'i1' => '1', |
485 |
'i2' => ' ' |
486 |
'a' => 'Goa', |
487 |
'f' => 'Valdo D\'Arienzo', |
488 |
'e' => 'tipografie e tipografi nel XVI secolo', |
489 |
} |
490 |
], |
491 |
|
492 |
In case there are repeatable subfields in record, this will create |
493 |
following structure: |
494 |
|
495 |
'900' => [ { |
496 |
'a' => [ 'foo', 'bar', 'baz' ], |
497 |
}] |
498 |
|
499 |
Or in more complex example of |
500 |
|
501 |
902 ^aa1^aa2^aa3^bb1^aa4^bb2^cc1^aa5 |
502 |
|
503 |
it will create |
504 |
|
505 |
902 => [ |
506 |
{ a => ["a1", "a2", "a3", "a4", "a5"], b => ["b1", "b2"], c => "c1" }, |
507 |
], |
508 |
|
509 |
This behaviour can be changed using C<join_subfields_with> option to L</new>, |
510 |
in which case C<to_hash> will always create single value for each subfield. |
511 |
This will change result to: |
512 |
|
513 |
|
514 |
|
515 |
This method will also create additional field C<000> with MFN. |
516 |
|
517 |
There is also more elaborative way to call C<to_hash> like this: |
518 |
|
519 |
my $hash = $isis->to_hash({ |
520 |
mfn => 42, |
521 |
include_subfields => 1, |
522 |
}); |
523 |
|
524 |
Each option controll creation of hash: |
525 |
|
526 |
=over 4 |
527 |
|
528 |
=item mfn |
529 |
|
530 |
Specify MFN number of record |
531 |
|
532 |
=item include_subfields |
533 |
|
534 |
This option will create additional key in hash called C<subfields> which will |
535 |
have original record subfield order and index to that subfield like this: |
536 |
|
537 |
902 => [ { |
538 |
a => ["a1", "a2", "a3", "a4", "a5"], |
539 |
b => ["b1", "b2"], |
540 |
c => "c1", |
541 |
subfields => ["a", 0, "a", 1, "a", 2, "b", 0, "a", 3, "b", 1, "c", 0, "a", 4], |
542 |
} ], |
543 |
|
544 |
=item join_subfields_with |
545 |
|
546 |
Define delimiter which will be used to join repeatable subfields. You can |
547 |
specify option here instead in L</new> if you want to have per-record control. |
548 |
|
549 |
=back |
550 |
|
551 |
=cut |
552 |
|
553 |
sub to_hash { |
554 |
my $self = shift; |
555 |
|
556 |
|
557 |
my $mfn = shift || confess "need mfn!"; |
558 |
my $arg; |
559 |
|
560 |
if (ref($mfn) eq 'HASH') { |
561 |
$arg = $mfn; |
562 |
$mfn = $arg->{mfn} || confess "need mfn in arguments"; |
563 |
} |
564 |
|
565 |
# init record to include MFN as field 000 |
566 |
my $rec = { '000' => [ $mfn ] }; |
567 |
|
568 |
my $row = $self->fetch($mfn) || return; |
569 |
|
570 |
my $j_rs = $arg->{join_subfields_with}; |
571 |
$j_rs = $self->{join_subfields_with} unless(defined($j_rs)); |
572 |
my $i_sf = $arg->{include_subfields}; |
573 |
|
574 |
foreach my $f_nr (keys %{$row}) { |
575 |
foreach my $l (@{$row->{$f_nr}}) { |
576 |
|
577 |
# filter output |
578 |
if ($self->{'hash_filter'}) { |
579 |
$l = $self->{'hash_filter'}->($l, $f_nr); |
580 |
next unless defined($l); |
581 |
} |
582 |
|
583 |
my $val; |
584 |
my $r_sf; # repeatable subfields in this record |
585 |
|
586 |
# has identifiers? |
587 |
($val->{'i1'},$val->{'i2'}) = ($1,$2) if ($l =~ s/^([01 #])([01 #])\^/\^/); |
588 |
|
589 |
# has subfields? |
590 |
if ($l =~ m/\^/) { |
591 |
foreach my $t (split(/\^/,$l)) { |
592 |
next if (! $t); |
593 |
my ($sf,$v) = (substr($t,0,1), substr($t,1)); |
594 |
# XXX this might be option, but why? |
595 |
next unless ($v); |
596 |
# warn "### $f_nr^$sf:$v",$/ if ($self->{debug} > 1); |
597 |
|
598 |
if (ref( $val->{$sf} ) eq 'ARRAY') { |
599 |
|
600 |
push @{ $val->{$sf} }, $v; |
601 |
|
602 |
# record repeatable subfield it it's offset |
603 |
push @{ $val->{subfields} }, ( $sf, $#{ $val->{$sf} } ) if (! $j_rs && $i_sf); |
604 |
$r_sf->{$sf}++; |
605 |
|
606 |
} elsif (defined( $val->{$sf} )) { |
607 |
|
608 |
# convert scalar field to array |
609 |
$val->{$sf} = [ $val->{$sf}, $v ]; |
610 |
|
611 |
push @{ $val->{subfields} }, ( $sf, 1 ) if (! $j_rs && $i_sf); |
612 |
$r_sf->{$sf}++; |
613 |
|
614 |
} else { |
615 |
$val->{$sf} = $v; |
616 |
push @{ $val->{subfields} }, ( $sf, 0 ) if ($i_sf); |
617 |
} |
618 |
} |
619 |
} else { |
620 |
$val = $l; |
621 |
} |
622 |
|
623 |
if ($j_rs) { |
624 |
map { |
625 |
$val->{$_} = join($j_rs, @{ $val->{$_} }); |
626 |
} keys %$r_sf |
627 |
} |
628 |
|
629 |
push @{$rec->{$f_nr}}, $val; |
630 |
} |
631 |
} |
632 |
|
633 |
return $rec; |
634 |
} |
635 |
|
636 |
=head2 tag_name |
637 |
|
638 |
Return name of selected tag |
639 |
|
640 |
print $isis->tag_name('200'); |
641 |
|
642 |
=cut |
643 |
|
644 |
sub tag_name { |
645 |
my $self = shift; |
646 |
my $tag = shift || return; |
647 |
return $self->{'TagName'}->{$tag} || $tag; |
648 |
} |
649 |
|
650 |
|
651 |
=head2 read_cnt |
652 |
|
653 |
Read content of C<.CNT> file and return hash containing it. |
654 |
|
655 |
print Dumper($isis->read_cnt); |
656 |
|
657 |
This function is not used by module (C<.CNT> files are not required for this |
658 |
module to work), but it can be useful to examine your index (while debugging |
659 |
for example). |
660 |
|
661 |
=cut |
662 |
|
663 |
sub read_cnt { |
664 |
my $self = shift; |
665 |
|
666 |
croak "missing CNT file in ",$self->{isisdb} unless ($self->{cnt_file}); |
667 |
|
668 |
# Get the index information from $db.CNT |
669 |
|
670 |
open(my $fileCNT, $self->{cnt_file}) || croak "can't read '$self->{cnt_file}': $!"; |
671 |
binmode($fileCNT); |
672 |
|
673 |
my $buff; |
674 |
|
675 |
read($fileCNT, $buff, 26) || croak "can't read first table from CNT: $!"; |
676 |
$self->unpack_cnt($buff); |
677 |
|
678 |
read($fileCNT, $buff, 26) || croak "can't read second table from CNT: $!"; |
679 |
$self->unpack_cnt($buff); |
680 |
|
681 |
close($fileCNT); |
682 |
|
683 |
return $self->{cnt}; |
684 |
} |
685 |
|
686 |
=head2 unpack_cnt |
687 |
|
688 |
Unpack one of two 26 bytes fixed length record in C<.CNT> file. |
689 |
|
690 |
Here is definition of record: |
691 |
|
692 |
off key description size |
693 |
0: IDTYPE BTree type s |
694 |
2: ORDN Nodes Order s |
695 |
4: ORDF Leafs Order s |
696 |
6: N Number of Memory buffers for nodes s |
697 |
8: K Number of buffers for first level index s |
698 |
10: LIV Current number of Index Levels s |
699 |
12: POSRX Pointer to Root Record in N0x l |
700 |
16: NMAXPOS Next Available position in N0x l |
701 |
20: FMAXPOS Next available position in L0x l |
702 |
24: ABNORMAL Formal BTree normality indicator s |
703 |
length: 26 bytes |
704 |
|
705 |
This will fill C<$self> object under C<cnt> with hash. It's used by C<read_cnt>. |
706 |
|
707 |
=cut |
708 |
|
709 |
sub unpack_cnt { |
710 |
my $self = shift; |
711 |
|
712 |
my @flds = qw(ORDN ORDF N K LIV POSRX NMAXPOS FMAXPOS ABNORMAL); |
713 |
|
714 |
my $buff = shift || return; |
715 |
my @arr = unpack("vvvvvvVVVv", $buff); |
716 |
|
717 |
print STDERR "unpack_cnt: ",join(" ",@arr),"\n" if ($self->{'debug'}); |
718 |
|
719 |
my $IDTYPE = shift @arr; |
720 |
foreach (@flds) { |
721 |
$self->{cnt}->{$IDTYPE}->{$_} = abs(shift @arr); |
722 |
} |
723 |
} |
724 |
|
725 |
1; |
726 |
|
727 |
=head1 BUGS |
728 |
|
729 |
Some parts of CDS/ISIS documentation are not detailed enough to exmplain |
730 |
some variations in input databases which has been tested with this module. |
731 |
When I was in doubt, I assumed that OpenIsis's implementation was right |
732 |
(except for obvious bugs). |
733 |
|
734 |
However, every effort has been made to test this module with as much |
735 |
databases (and programs that create them) as possible. |
736 |
|
737 |
I would be very greatful for success or failure reports about usage of this |
738 |
module with databases from programs other than WinIsis and IsisMarc. I had |
739 |
tested this against ouput of one C<isis.dll>-based application, but I don't |
740 |
know any details about it's version. |
741 |
|
742 |
=head1 VERSIONS |
743 |
|
744 |
As this is young module, new features are added in subsequent version. It's |
745 |
a good idea to specify version when using this module like this: |
746 |
|
747 |
use Biblio::Isis 0.21 |
748 |
|
749 |
Below is list of changes in specific version of module (so you can target |
750 |
older versions if you really have to): |
751 |
|
752 |
=over 8 |
753 |
|
754 |
=item 0.21 |
755 |
|
756 |
Added C<join_subfields_with> to L</new> and L</to_hash>. |
757 |
|
758 |
Added C<include_subfields> to L</to_hash>. |
759 |
|
760 |
=item 0.20 |
761 |
|
762 |
Added C<< $isis->mfn >>, support for repeatable subfields and |
763 |
C<< $isis->to_hash({ mfn => 42, ... }) >> calling convention |
764 |
|
765 |
=back |
766 |
|
767 |
=head1 AUTHOR |
768 |
|
769 |
Dobrica Pavlinusic |
770 |
CPAN ID: DPAVLIN |
771 |
dpavlin@rot13.org |
772 |
http://www.rot13.org/~dpavlin/ |
773 |
|
774 |
This module is based heavily on code from C<LIBISIS.PHP> library to read ISIS files V0.1.1 |
775 |
written in php and (c) 2000 Franck Martin <franck@sopac.org> and released under LGPL. |
776 |
|
777 |
=head1 COPYRIGHT |
778 |
|
779 |
This program is free software; you can redistribute |
780 |
it and/or modify it under the same terms as Perl itself. |
781 |
|
782 |
The full text of the license can be found in the |
783 |
LICENSE file included with this module. |
784 |
|
785 |
|
786 |
=head1 SEE ALSO |
787 |
|
788 |
L<Biblio::Isis::Manual> for CDS/ISIS manual appendix F, G and H which describe file format |
789 |
|
790 |
OpenIsis web site L<http://www.openisis.org> |
791 |
|
792 |
perl4lib site L<http://perl4lib.perl.org> |
793 |
|