1 # $Id: Session.pm,v 1.13 2003-03-05 13:55:22 pop Exp $
3 # Zebra perl API header
4 # =============================================================================
5 package IDZebra::Session;
13 use IDZebra::Logger qw(:flags :calls);
14 use IDZebra::Resultset;
15 use IDZebra::ScanList;
16 use IDZebra::RetrievalRecord;
18 our $VERSION = do { my @r = (q$Revision: 1.13 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
19 our @ISA = qw(IDZebra::Logger Exporter);
20 our @EXPORT = qw (TRANS_RW TRANS_RO);
23 use constant TRANS_RW => 1;
24 use constant TRANS_RO => 0;
27 # -----------------------------------------------------------------------------
28 # Class constructors, destructor
29 # -----------------------------------------------------------------------------
31 my ($proto, %args) = @_;
32 my $class = ref($proto) || $proto;
34 $self->{args} = \%args;
36 bless ($self, $class);
37 $self->{cql_ct} = undef;
38 $self->{cql_mapfile} = "";
41 $self->{databases} = {};
45 my ($self, %args) = @_;
48 unless (defined($self->{zs})) {
49 if (defined($args{'configFile'})) {
50 $self->{zs} = IDZebra::start($args{'configFile'});
52 $self->{zs} = IDZebra::start("zebra.cfg");
59 if (defined($self->{zs})) {
60 IDZebra::stop($self->{zs}) if ($self->{zs});
67 my ($proto,%args) = @_;
70 if (ref($proto)) { $self = $proto; } else {
71 $self = $proto->new(%args);
75 %args = %{$self->{args}};
78 $self->start_service(%args);
80 unless (defined($self->{zs})) {
81 croak ("Falied to open zebra service");
84 unless (defined($self->{zh})) {
85 $self->{zh}=IDZebra::open($self->{zs});
88 # Reset result set counter
91 # This is needed in order to somehow initialize the service
92 $self->databases("Default");
94 # Load the default configuration
99 my $shadow = defined($args{shadow}) ? $args{shadow} : 0;
100 $self->shadow($shadow);
102 $self->{odr_input} = IDZebra::odr_createmem($IDZebra::ODR_DECODE);
103 $self->{odr_output} = IDZebra::odr_createmem($IDZebra::ODR_ENCODE);
110 unless (defined($self->{zh})) {
111 croak ("Zebra session is not opened");
121 # Delete all resulsets
122 my $r = IDZebra::deleteResultSet($self->{zh},
123 1, #Z_DeleteRequest_all,
127 while (IDZebra::trans_no($self->{zh}) > 0) {
128 logf (LOG_WARN,"Explicitly closing transaction with session");
132 IDZebra::close($self->{zh});
136 if ($self->{odr_input}) {
137 IDZebra::odr_reset($self->{odr_input});
138 IDZebra::odr_destroy($self->{odr_input});
139 $self->{odr_input} = undef;
142 if ($self->{odr_output}) {
143 IDZebra::odr_reset($self->{odr_output});
144 IDZebra::odr_destroy($self->{odr_output});
145 $self->{odr_output} = undef;
153 logf (LOG_LOG,"DESTROY $self");
156 if (defined ($self->{cql_ct})) {
157 IDZebra::cql_transform_close($self->{cql_ct});
161 # -----------------------------------------------------------------------------
162 # Record group selection This is a bit nasty... but used at many places
163 # -----------------------------------------------------------------------------
165 my ($self,%args) = @_;
168 $self->{rg} = $self->_makeRecordGroup(%args);
169 $self->_selectRecordGroup($self->{rg});
174 sub selectRecordGroup {
175 my ($self, $groupName) = @_;
177 $self->{rg} = $self->_getRecordGroup($groupName);
178 $self->_selectRecordGroup($self->{rg});
181 sub _displayRecordGroup {
182 my ($self, $rg) = @_;
183 print STDERR "-----\n";
184 foreach my $key qw (groupName
195 print STDERR "$key:",$rg->{$key},"\n";
199 sub _cloneRecordGroup {
200 my ($self, $orig) = @_;
201 my $rg = IDZebra::recordGroup->new();
202 my $r = IDZebra::init_recordGroup($rg);
203 foreach my $key qw (groupName
215 $rg->{$key} = $orig->{$key} if ($orig->{$key});
220 sub _getRecordGroup {
221 my ($self, $groupName, $ext) = @_;
222 my $rg = IDZebra::recordGroup->new();
223 my $r = IDZebra::init_recordGroup($rg);
224 $rg->{groupName} = $groupName if ($groupName ne "");
225 $ext = "" unless ($ext);
226 $r = IDZebra::res_get_recordGroup($self->{zh}, $rg, $ext);
230 sub _makeRecordGroup {
231 my ($self, %args) = @_;
234 my @keys = keys(%args);
235 unless ($#keys >= 0) {
236 return ($self->{rg});
239 if ($args{groupName}) {
240 $rg = $self->_getRecordGroup($args{groupName});
242 $rg = $self->_cloneRecordGroup($self->{rg});
244 $self->_setRecordGroupOptions($rg, %args);
248 sub _setRecordGroupOptions {
249 my ($self, $rg, %args) = @_;
251 foreach my $key qw (databaseName
262 if (defined ($args{$key})) {
263 $rg->{$key} = $args{$key};
267 sub _selectRecordGroup {
268 my ($self, $rg) = @_;
269 my $r = IDZebra::set_group($self->{zh}, $rg);
271 unless ($dbName = $rg->{databaseName}) {
274 unless ($self->databases($dbName)) {
275 croak("Fatal error selecting database $dbName");
278 # -----------------------------------------------------------------------------
279 # Selecting databases for search (and also for updating - internally)
280 # -----------------------------------------------------------------------------
282 my ($self, @databases) = @_;
287 return (keys(%{$self->{databases}}));
293 foreach my $db (@databases) {
294 next if ($self->{databases}{$db});
299 foreach my $db (keys (%{$self->{databases}})) {
300 $changed++ unless ($tmp{$db});
305 delete ($self->{databases});
306 foreach my $db (@databases) {
307 $self->{databases}{$db}++;
310 if (IDZebra::select_databases($self->{zh},
314 "Could not select database(s) %s errCode=%d",
315 join(",",@databases),
319 logf(LOG_LOG,"Database(s) selected: %s",join(",",@databases));
322 return (keys(%{$self->{databases}}));
325 # -----------------------------------------------------------------------------
327 # -----------------------------------------------------------------------------
330 return(IDZebra::errCode($self->{zh}));
335 return(IDZebra::errString($self->{zh}));
340 return(IDZebra::errAdd($self->{zh}));
343 # -----------------------------------------------------------------------------
345 # -----------------------------------------------------------------------------
348 $m = TRANS_RW unless (defined ($m));
349 if (my $err = IDZebra::begin_trans($self->{zh},$m)) {
350 if ($self->errCode == 2) {
351 croak ("TRANS_RW not allowed within TRANS_RO");
353 croak("Error starting transaction; code:".
354 $self->errCode . " message: " . $self->errString);
362 my $stat = IDZebra::ZebraTransactionStatus->new();
363 IDZebra::end_trans($self->{zh}, $stat);
368 my ($self, $value) = @_;
371 $value = 0 unless (defined($value));
372 my $r =IDZebra::set_shadow_enable($self->{zh},$value);
374 return (IDZebra::get_shadow_enable($self->{zh}));
381 return(IDZebra::commit($self->{zh}));
385 # -----------------------------------------------------------------------------
386 # We don't really need that...
387 # -----------------------------------------------------------------------------
389 my ($self, $name) = @_;
390 if ($name !~/^(input|output)$/) {
391 croak("Undefined ODR '$name'");
393 IDZebra::odr_reset($self->{"odr_$name"});
396 # -----------------------------------------------------------------------------
398 # -----------------------------------------------------------------------------
402 return(IDZebra::init($self->{zh}));
408 return(IDZebra::compact($self->{zh}));
412 my ($self, %args) = @_;
414 my $rg = $self->_update_args(%args);
415 $self->_selectRecordGroup($rg);
417 IDZebra::repository_update($self->{zh});
418 $self->_selectRecordGroup($self->{rg});
423 my ($self, %args) = @_;
425 my $rg = $self->_update_args(%args);
426 $self->_selectRecordGroup($rg);
428 IDZebra::repository_delete($self->{zh});
429 $self->_selectRecordGroup($self->{rg});
434 my ($self, %args) = @_;
436 my $rg = $self->_update_args(%args);
437 $self->_selectRecordGroup($rg);
439 IDZebra::repository_show($self->{zh});
440 $self->_selectRecordGroup($self->{rg});
445 my ($self, %args) = @_;
446 my $rg = $self->_makeRecordGroup(%args);
447 $self->_selectRecordGroup($rg);
451 # -----------------------------------------------------------------------------
453 # -----------------------------------------------------------------------------
456 my ($self, %args) = @_;
458 return(IDZebra::update_record($self->{zh},
459 $self->_record_update_args(%args)));
463 my ($self, %args) = @_;
465 return(IDZebra::delete_record($self->{zh},
466 $self->_record_update_args(%args)));
468 sub _record_update_args {
469 my ($self, %args) = @_;
471 my $sysno = $args{sysno} ? $args{sysno} : 0;
472 my $match = $args{match} ? $args{match} : "";
473 my $rectype = $args{recordType} ? $args{recordType} : "";
474 my $fname = $args{file} ? $args{file} : "<no file>";
481 elsif ($args{file}) {
482 CORE::open (F, $args{file}) || warn ("Cannot open $args{file}");
483 $buff = join('',(<F>));
486 my $len = length($buff);
488 delete ($args{sysno});
489 delete ($args{match});
490 delete ($args{recordType});
491 delete ($args{file});
492 delete ($args{data});
494 my $rg = $self->_makeRecordGroup(%args);
496 # If no record type is given, then try to find it out from the
499 if (my ($ext) = $fname =~ /\.(\w+)$/) {
500 my $rg2 = $self->_getRecordGroup($rg->{groupName},$ext);
501 $rectype = $rg2->{recordType};
505 $rg->{databaseName} = "Default" unless ($rg->{databaseName});
510 return ($rg, $rectype, $sysno, $match, $fname, $buff, $len);
513 # -----------------------------------------------------------------------------
516 my ($self,$mapfile) = @_;
518 if ($self->{cql_mapfile} ne $mapfile) {
519 unless (-f $mapfile) {
520 croak("Cannot find $mapfile");
522 if (defined ($self->{cql_ct})) {
523 IDZebra::cql_transform_close($self->{cql_ct});
525 $self->{cql_ct} = IDZebra::cql_transform_open_fname($mapfile);
526 $self->{cql_mapfile} = $mapfile;
529 return ($self->{cql_mapfile});
533 my ($self, $cqlquery) = @_;
534 unless (defined($self->{cql_ct})) {
535 croak("CQL map file is not specified yet.");
537 my $res = "\0" x 2048;
538 my $r = IDZebra::cql2pqf($self->{cql_ct}, $cqlquery, $res, 2048);
540 carp ("Error transforming CQL query: '$cqlquery', status:$r");
547 # -----------------------------------------------------------------------------
549 # -----------------------------------------------------------------------------
551 my ($self, %args) = @_;
555 if ($args{cqlmap}) { $self->cqlmap($args{cqlmap}); }
563 ($query, $cqlstat) = $self->cql2pqf($args{cql});
565 croak ("Failed to transform query: '$args{cql}', ".
566 "status: ($cqlstat)");
570 croak ("No query given to search");
575 if ($args{databases}) {
576 @origdbs = $self->databases;
577 $self->databases(@{$args{databases}});
580 my $rsname = $args{rsname} ? $args{rsname} : $self->_new_setname;
582 my $rs = $self->_search_pqf($query, $rsname);
584 if ($args{databases}) {
585 $self->databases(@origdbs);
590 carp("Sort skipped due to search error: ".
593 $rs->sort($args{sort});
602 return ("set_".$self->{rscount}++);
606 my ($self, $query, $setname) = @_;
608 my $hits = IDZebra::search_PQF($self->{zh},
614 my $rs = IDZebra::Resultset->new($self,
616 recordCount => $hits,
617 errCode => $self->errCode,
618 errString => $self->errString);
622 # -----------------------------------------------------------------------------
625 # Sorting of multiple result sets is not supported by zebra...
626 # -----------------------------------------------------------------------------
629 my ($self, $sortspec, $setname, @sets) = @_;
634 croak ("Sorting/merging of multiple resultsets is not supported now");
639 foreach my $rs (@sets) {
640 push (@setnames, $rs->{name});
641 $count += $rs->{recordCount}; # is this really sure ??? It doesn't
645 my $status = IDZebra::sort($self->{zh},
651 my $errCode = $self->errCode;
652 my $errString = $self->errString;
654 logf (LOG_LOG, "Sort status $setname: %d, errCode: %d, errString: %s",
655 $status, $errCode, $errString);
657 if ($status || $errCode) {$count = 0;}
659 my $rs = IDZebra::Resultset->new($self,
661 recordCount => $count,
663 errString => $errString);
667 # -----------------------------------------------------------------------------
669 # -----------------------------------------------------------------------------
671 my ($self, %args) = @_;
675 unless ($args{expression}) {
676 croak ("No scan expression given");
679 my $sl = IDZebra::ScanList->new($self,%args);
684 # ============================================================================
691 IDZebra::Session - A Zebra database server session for update and retrieval
695 $sess = IDZebra::Session->new(configFile => 'demo/zebra.cfg');
698 $sess = IDZebra::Session->open(configFile => 'demo/zebra.cfg',
699 groupName => 'demo1');
701 $sess->group(groupName => 'demo2');
707 $sess->update(path => 'lib');
709 my $s1=$sess->update_record(data => $rec1,
710 recordType => 'grs.perl.pod',
711 groupName => "demo1",
714 my $stat = $sess->end_trans;
716 $sess->databases('demo1','demo2');
718 my $rs1 = $sess->search(cqlmap => 'demo/cql.map',
719 cql => 'dc.title=IDZebra',
720 databases => [qw(demo1 demo2)]);
725 Zebra is a high-performance, general-purpose structured text indexing and retrieval engine. It reads structured records in a variety of input formats (eg. email, XML, MARC) and allows access to them through exact boolean search expressions and relevance-ranked free-text queries.
727 Zebra supports large databases (more than ten gigabytes of data, tens of millions of records). It supports incremental, safe database updates on live systems. You can access data stored in Zebra using a variety of Index Data tools (eg. YAZ and PHP/YAZ) as well as commercial and freeware Z39.50 clients and toolkits.
729 =head1 OPENING AND CLOSING A ZEBRA SESSIONS
731 For the time beeing only local database services are supported, the same way as calling zebraidx or zebrasrv from the command shell. In order to open a local Zebra database, with a specific configuration file, use
733 $sess = IDZebra::Session->new(configFile => 'demo/zebra.cfg');
738 $sess = IDZebra::Session->open(configFile => 'demo/zebra.cfg');
740 where $sess is going to be the object representing a Zebra Session. Whenever this variable gets out of scope, the session is closed, together with all active transactions, etc... Anyway, if you'd like to close the session, just say:
745 - close all transactions
746 - destroy all result sets and scan lists
749 Note, that if I<shadow registers> are enabled, the changes will not be committed automatically.
751 In the future different database access methods are going to be available,
754 $sess = IDZebra::Session->open(server => 'ostrich.technomat.hu:9999');
756 You can also use the B<record group> arguments described below directly when calling the constructor, or the open method:
758 $sess = IDZebra::Session->open(configFile => 'demo/zebra.cfg',
759 groupName => 'demo');
764 If you manage different sets of records that share common characteristics, you can organize the configuration settings for each type into "groups". See the Zebra manual on the configuration file (zebra.cfg).
766 For each open session a default record group is assigned. You can configure it in the constructor, or by the B<group> method:
768 $sess->group(groupName => ..., ...)
770 The following options are available:
776 This will select the named record group, and load the corresponding settings from the configuration file. All subsequent values will overwrite those...
778 =item B<databaseName>
780 The name of the (logical) database the updated records will belong to.
784 This path is used for directory updates (B<update>, B<delete> methods);
788 This option determines how to identify your records. See I<Zebra manual: Locating Records>
792 The record type used for indexing.
794 =item B<flagStoreData>
796 Specifies whether the records should be stored internally in the Zebra system files. If you want to maintain the raw records yourself, this option should be false (0). If you want Zebra to take care of the records for you, it should be true(1).
798 =item B<flagStoreKeys>
800 Specifies whether key information should be saved for a given group of records. If you plan to update/delete this type of records later this should be specified as 1; otherwise it should be 0 (default), to save register space.
806 =item B<fileVerboseLimit>
808 Skip log messages, when doing a directory update, and the specified number of files are processed...
810 =item B<databaseNamePath>
814 =item B<explainDatabase>
816 The name of the explain database to be used
820 Follow links when doing directory update.
824 You can use the same parameters calling all update methods.
826 =head1 TRANSACTIONS (READ / WRITE LOCKS)
828 A transaction is a block of record update (insert / modify / delete) or retrieval procedures. So, all call to such function will implicitly start a transaction, unless one is already started by
834 $sess->begin_trans(TRANS_RW)
836 (these two are equivalents). The effect of this call is a kind of lock: if you call is a write lock is put on the registers, so other processes trying to update the database will be blocked. If there is already an RW (Read-Write) transaction opened by another process, the I<begin_trans> call will be blocked.
840 $sess->begin_trans(TRANS_RO),
842 if you would like to put on a "read lock". This one is B<deprecated>, as while you have explicitly opened a transaction for read, you can't open another one for update. For example:
844 $sess->begin_trans(TRANS_RO);
845 $sess->begin_tran(TRANS_RW); # invalid, die here
851 $sess->begin_tran(TRANS_RW);
852 $sess->begin_trans(TRANS_RO);
856 is valid, but probably useless. Note again, that for each retrieval call, an RO transaction is opened. I<TRANS_RW> and I<TRANS_RO> are exported by default by IDZebra::Session.pm.
858 For multiple per-record I<updates> it's efficient to start transactions explicitly: otherwise registers (system files, vocabularies, etc..) are updated one by one. After finishing all requested updates, use
860 $stat = $sess->end_trans;
862 The return value is a ZebraTransactionStatus object, containing the following members as a hash reference:
864 $stat->{processed} # Number of records processed
865 $stat->{updated} # Number of records processed
866 $stat->{deleted} # Number of records processed
867 $stat->{inserted} # Number of records processed
868 $stat->{stime} # System time used
869 $stat->{utime} # User time used
871 Normally, if the perl code dies due to some runtime error, or the session is closed, then the API attempts to close all pending transactions.
873 =head1 THE SHADOW REGISTERS
875 The Zebra server supports updating of the index structures. That is, you can add, modify, or remove records from databases managed by Zebra without rebuilding the entire index. Since this process involves modifying structured files with various references between blocks of data in the files, the update process is inherently sensitive to system crashes, or to process interruptions: Anything but a successfully completed update process will leave the register files in an unknown state, and you will essentially have no recourse but to re-index everything, or to restore the register files from a backup medium. Further, while the update process is active, users cannot be allowed to access the system, as the contents of the register files may change unpredictably.
877 You can solve these problems by enabling the shadow register system in Zebra. During the updating procedure, zebraidx will temporarily write changes to the involved files in a set of "shadow files", without modifying the files that are accessed by the active server processes. If the update procedure is interrupted by a system crash or a signal, you simply repeat the procedure - the register files have not been changed or damaged, and the partially written shadow files are automatically deleted before the new updating procedure commences.
879 At the end of the updating procedure (or in a separate operation, if you so desire), the system enters a "commit mode". First, any active server processes are forced to access those blocks that have been changed from the shadow files rather than from the main register files; the unmodified blocks are still accessed at their normal location (the shadow files are not a complete copy of the register files - they only contain those parts that have actually been modified). If the commit process is interrupted at any point during the commit process, the server processes will continue to access the shadow files until you can repeat the commit procedure and complete the writing of data to the main register files. You can perform multiple update operations to the registers before you commit the changes to the system files, or you can execute the commit operation at the end of each update operation. When the commit phase has completed successfully, any running server processes are instructed to switch their operations to the new, operational register, and the temporary shadow files are deleted.
881 By default, (in the API !) the use of shadow registers is disabled. If zebra is configured that way (there is a "shadow" entry in zebra.cfg), then the shadow system can be enabled by calling:
889 If shadow system is enabled, then you have to commit changes you did, by calling:
893 Note, that you can also determine shadow usage in the session constructor:
895 $sess = IDZebra::Session->open(configFile => 'demo/zebra.cfg',
898 Changes to I<shadow> will not have effect, within a I<transaction> (ie.: a transaction is started either with shadow enabled or disabled). For more details, read Zebra documentation: I<Safe Updating - Using Shadow Registers>.
902 There are two ways to update data in a Zebra database using the perl API. You can update an entire directory structure just the way it's done by zebraidx:
904 $sess->update(path => 'lib');
906 This will update the database with the files in directory "lib", according to the current record group settings.
910 This will update the database with the files, specified by the default record group setting. I<path> has to be specified there...
912 $sess->update(groupName => 'demo1',
915 Update the database with files in "lib" according to the settings of group "demo1"
917 $sess->delete(groupName => 'demo1',
920 Delete the records derived from the files in directory "lib", according to the "demo1" group settings. Sounds complex? Read zebra documentation about identifying records.
922 You can also update records one by one, even directly from the memory:
924 $sysno = $sess->update_record(data => $rec1,
925 recordType => 'grs.perl.pod',
926 groupName => "demo1");
928 This will update the database with the given record buffer. Note, that in this case recordType is explicitly specified, as there is no filename given, and for the demo1 group, no default record type is specified. The return value is the system assigned id of the record.
930 You can also index a single file:
932 $sysno = $sess->update_record(file => "lib/IDZebra/Data1.pm");
934 Or, provide a buffer, and a filename (where filename will only be used to identify the record, if configured that way, and possibly to find out it's record type):
936 $sysno = $sess->update_record(data => $rec1,
937 file => "lib/IDZebra/Data1.pm");
939 And some crazy stuff:
941 $sysno = $sess->delete_record(sysno => $sysno);
943 where sysno in itself is sufficient to identify the record
945 $sysno = $sess->delete_record(data => $rec1,
946 recordType => 'grs.perl.pod',
947 groupName => "demo1");
949 This case the record is extracted, and if already exists, located in the database, then deleted...
951 $sysno = $sess->delete_record(data => $rec1,
953 recordType => 'grs.perl.pod',
954 groupName => "demo1");
956 Don't try this at home! This case, the record identifier string (which is normally generated according to the rules set in recordId directive of zebra.cfg) is provided directly....
959 B<Important:> Note, that one record can be updated only once within a transaction - all subsequent updates are skipped.
961 =head1 DATABASE SELECTION
963 Within a zebra repository you can define logical databases. You can either do this by record groups, or by providing the databaseName argument for update methods. For each record the database name it belongs to is stored.
965 For searching, you can select databases by calling:
967 $sess->databases('db1','db2');
969 This will not do anything if the given and only the given databases are already selected. You can get the list of the actually selected databases, by calling:
971 @dblist = $sess->databases();
975 It's nice to be able to store data in your repository... But it's useful to reach it as well. So this is how to do searching:
977 $rs = $sess->search(databases => [qw(demo1,demo2)], # optional
978 pqf => '@attr 1=4 computer');
980 This is going to execute a search in databases demo1 and demo2, for title 'com,puter'. This is a PQF (Prefix Query Format) search, see YAZ documentation for details. The database selection is optional: if it's provided, the given list of databases is selected for this particular search, then the original selection is restored.
984 Not all users enjoy typing in prefix query structures and numerical attribute values, even in a minimalistic test client. In the library world, the more intuitive Common Command Language (or ISO 8777) has enjoyed some popularity - especially before the widespread availability of graphical interfaces. It is still useful in applications where you for some reason or other need to provide a symbolic language for expressing boolean query structures.
986 The CCL searching is not currently supported by this API.
990 CQL - Common Query Language - was defined for the SRW protocol. In many ways CQL has a similar syntax to CCL. The objective of CQL is different. Where CCL aims to be an end-user language, CQL is the protocol query language for SRW.
992 In order to map CQL queries to Zebra internal search structures, you have to define a mapping, the way it is described in YAZ documentation: I<Specification of CQL to RPN mapping>. The mapping is interpreted by the method:
994 $sess->cqlmap($mapfile);
996 Or, you can directly provide the I<mapfile> parameter for the search:
998 $rs = $sess->search(cqlmap => 'demo/cql.map',
999 cql => 'dc.title=IDZebra');
1001 As you see, CQL searching is so simple: just give the query in the I<cql> parameter.
1005 If you'd like the search results to be sorted, use the I<sort> parameter:
1007 $rs = $sess->search(cql => 'IDZebra',
1010 Note, that B<currently> this is (almost) equivalent to
1012 $rs = $sess->search(cql => 'IDZebra');
1013 $rs->sort('1=4 ia');
1015 but in the further versions of Zebra and this API a single phase search and sort will take place, optimizing performance. For more details on sorting, see I<IDZebra::ResultSet> manpage.
1019 As you have seen, the result of the search request is a I<Resultset> object.
1020 It contains number of hits, and search status, and can be used to sort and retrieve the resulting records.
1022 $count = $rs->count;
1024 printf ("RS Status is %d (%s)\n", $rs->errCode, $rs->errString);
1026 I<$rs-E<gt>errCode> is 0, if there were no errors during search. Read the I<IDZebra::Resultset> manpage for more details.
1030 Zebra supports scanning index values. The result of the
1032 $sl = $sess->scan(expression => "a");
1034 call is an I<IDZebra::ScanList> object, what you can use to list the values. The scan expression has to be provided in a PQF like format. Examples:
1036 B< a> (scan trough words of "default", "Any" indexes)
1039 B< @attr 1=1016 a> (same effect)
1042 B< @attr 1=4 @attr 6=2 a> (scan trough titles as phrases)
1044 An illegal scan expression will cause your code to die. If you'd like to select databases just for the scan call, you can optionally use the I<databases> parameter:
1046 $sl = $sess->scan(expression => "a",
1047 databases => [qw(demo1 demo2)]);
1049 You can use the I<IDZebra::ScanList> object returned by the i<scan> method, to reach the result. Check I<IDZebra::ScanList> manpage for more details.
1051 =head1 SESSION STATUS AND ERRORS
1053 Most of the API calls causes die, if an error occures. You avoid this, by using eval {} blocks. The following methods are available to get the status of Zebra service:
1059 The Zebra provided error code... (for the result of the last call);
1063 Error string corresponding to the message
1067 Additional information for the status
1071 This functionality may change, see TODO.
1073 =head1 LOGGING AND MISC. FUNCTIONS
1075 Zebra provides logging facility for the internal events, and also for application developers trough the API. See manpage I<IDZebra::Logger> for details.
1079 =item B<IDZebra::LogFile($filename)>
1081 Will set the output file for logging. By default it's STDERR;
1083 =item B<IDZebra::LogLevel(15)>
1085 Set log level. 0 for no logs. See IDZebra::Logger for usable flags.
1089 Some other functions
1093 =item B<$sess-E<gt>init>
1095 Initialize, and clean registers. This will remove all data!
1097 =item B<$sess-E<gt>compact>
1099 Compact the registers (? does this work)
1101 =item B<$sess-E<gt>show>
1103 Doesn't have too much meaning. Don't try :)
1111 =item B<Clean up error handling>
1113 By default all zebra errors should cause die. (such situations could be avoided by using eval {}), and then check for errCode, errString... An optional flag or package variable should be introduced to override this, and skip zebra errors, to let the user decide what to do.
1115 =item B<Make the package self-distributable>
1117 Build and link with installed header and library files
1121 Test shadow system, unicode...
1125 Cleanup, arrange, remove redundancy
1135 Peter Popovics, pop@technomat.hu
1139 Zebra documentation, Zebra::ResultSet, Zebra::ScanList, Zebra::Logger manpages