3 ZOOM_connection_errcode(c)
4 ZOOM_connection_errmsg(c)
5 ZOOM_connection_addinfo(c)
6 ZOOM_connection_addinfo(c)
7 ZOOM_connection_diagset(c);
9 ZOOM_resultset_record_immediate(s, pos)
10 ZOOM_resultset_cache_reset(r)
11 ZOOM_resultset_sort(r, sort_type, sort_spec)
12 ZOOM_resultset_sort1(r, sort_type, sort_spec)
13 ZOOM_options_set_callback(opt, function, handle)
14 ZOOM_options_create_with_parent2(parent1, parent2)
15 ZOOM_options_getl(opt, name, len)
16 ZOOM_options_setl(opt, name, value, len)
17 ZOOM_options_get_bool(opt, name, defa)
18 ZOOM_options_get_int(opt, name, defa)
19 ZOOM_options_set_int(opt, name, value)
20 ZOOM_connection_scan1 (ZOOM_connection c, ZOOM_query startterm)
21 ZOOM_query_cql2rpn(ZOOM_query s, const char *str, ZOOM_connection conn)
23 <!-- $Id: zoom.xml,v 1.51 2006-09-06 09:26:36 adam Exp $ -->
24 <chapter id="zoom"><title>ZOOM</title>
26 &zoom; is an acronym for 'Z39.50 Object-Orientation Model' and is
27 an initiative started by Mike Taylor (Mike is from the UK, which
28 explains the peculiar name of the model). The goal of &zoom; is to
29 provide a common Z39.50 client API not bound to a particular
30 programming language or toolkit.
35 A recent addition to &yaz; is SRU support. You can now make
36 SRU ZOOM connections by specifying scheme <literal>http://</literal>
37 for the hostname for a connection.
42 The lack of a simple Z39.50 client API for &yaz; has become more
43 and more apparent over time. So when the first &zoom; specification
45 an implementation for &yaz; was quickly developed. For the first time, it is
46 now as easy (or easier!) to develop clients than servers with &yaz;. This
47 chapter describes the &zoom; C binding. Before going further, please
48 reconsider whether C is the right programming language for the job.
49 There are other language bindings available for &yaz;, and still
51 are in active development. See the
52 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
57 In order to fully understand this chapter you should read and
58 try the example programs <literal>zoomtst1.c</literal>,
59 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
64 The C language misses features found in object oriented languages
65 such as C++, Java, etc. For example, you'll have to manually,
66 destroy all objects you create, even though you may think of them as
67 temporary. Most objects has a <literal>_create</literal> - and a
68 <literal>_destroy</literal> variant.
69 All objects are in fact pointers to internal stuff, but you don't see
70 that because of typedefs. All destroy methods should gracefully ignore a
71 <literal>NULL</literal> pointer.
74 In each of the sections below you'll find a sub section called
75 protocol behavior, that describes how the API maps to the Z39.50
78 <sect1 id="zoom-connections"><title>Connections</title>
80 <para>The Connection object is a session with a target.
83 #include <yaz/zoom.h>
85 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
87 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
89 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
91 void ZOOM_connection_destroy (ZOOM_connection c);
94 Connection objects are created with either function
95 <function>ZOOM_connection_new</function> or
96 <function>ZOOM_connection_create</function>.
97 The former creates and automatically attempts to establish a network
98 connection with the target. The latter doesn't establish
99 a connection immediately, thus allowing you to specify options
100 before establishing network connection using the function
101 <function>ZOOM_connection_connect</function>.
102 If the port number, <literal>portnum</literal>, is zero, the
103 <literal>host</literal> is consulted for a port specification.
104 If no port is given, 210 is used. A colon denotes the beginning of
105 a port number in the host string. If the host string includes a
106 slash, the following part specifies a database for the connection.
109 You can prefix the host with a scheme followed by colon. The
110 default scheme is <literal>tcp</literal> (Z39.50 protocol).
111 The scheme <literal>http</literal> selects SRU over HTTP.
114 You can prefix the scheme-qualified host-string with one or more
116 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
117 sequences, each of which represents an option to be set into the
118 connection structure <emphasis>before</emphasis> the
119 protocol-level connection is forged and the initialisation
120 handshake takes place. This facility can be used to provide
121 authentication credentials, as in host-strings such as:
122 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
125 Connection objects should be destroyed using the function
126 <function>ZOOM_connection_destroy</function>.
129 void ZOOM_connection_option_set(ZOOM_connection c,
130 const char *key, const char *val);
132 void ZOOM_connection_option_setl(ZOOM_connection c,
134 const char *val, int len);
136 const char *ZOOM_connection_option_get(ZOOM_connection c,
138 const char *ZOOM_connection_option_getl(ZOOM_connection c,
143 The functions <function>ZOOM_connection_option_set</function> and
144 <function>ZOOM_connection_option_setl</function> allows you to
145 set an option given by <parameter>key</parameter> to the value
146 <parameter>value</parameter> for the connection.
147 For <function>ZOOM_connection_option_set</function>, the
148 value is assumed to be a 0-terminated string. Function
149 <function>ZOOM_connection_option_setl</function> specifies a
150 value of a certain size (len).
153 Functions <function>ZOOM_connection_option_get</function> and
154 <function>ZOOM_connection_option_getl</function> returns
155 the value for an option given by <parameter>key</parameter>.
157 <table id="zoom-connection-options" frame="top">
158 <title>ZOOM Connection Options</title>
160 <colspec colwidth="4*" colname="name"></colspec>
161 <colspec colwidth="7*" colname="description"></colspec>
162 <colspec colwidth="3*" colname="default"></colspec>
165 <entry>Option</entry>
166 <entry>Description</entry>
167 <entry>Default</entry>
172 implementationName</entry><entry>Name of Your client
173 </entry><entry>none</entry></row>
175 user</entry><entry>Authentication user name
176 </entry><entry>none</entry></row>
178 group</entry><entry>Authentication group name
179 </entry><entry>none</entry></row>
181 password</entry><entry>Authentication password.
182 </entry><entry>none</entry></row>
184 host</entry><entry>Target host. This setting is "read-only".
185 It's automatically set internally when connecting to a target.
186 </entry><entry>none</entry></row>
188 proxy</entry><entry>Proxy host
189 </entry><entry>none</entry></row>
191 async</entry><entry>If true (1) the connection operates in
192 asynchronous operation which means that all calls are non-blocking
194 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
195 </entry><entry>0</entry></row>
197 maximumRecordSize</entry><entry> Maximum size of single record.
198 </entry><entry>1 MB</entry></row>
200 preferredMessageSize</entry><entry> Maximum size of multiple records.
201 </entry><entry>1 MB</entry></row>
203 lang</entry><entry> Language for negotiation.
204 </entry><entry>none</entry></row>
206 charset</entry><entry> Character set for negotiation.
207 </entry><entry>none</entry></row>
209 serverImplementationId</entry><entry>
210 Implementation ID of server. (The old targetImplementationId
211 option is also supported for the benefit of old applications.)
212 </entry><entry>none</entry></row>
214 targetImplementationName</entry><entry>
215 Implementation Name of server. (The old
216 targetImplementationName option is also supported for the
217 benefit of old applications.)
218 </entry><entry>none</entry></row>
220 serverImplementationVersion</entry><entry>
221 Implementation Version of server. (the old
222 targetImplementationVersion option is also supported for the
223 benefit of old applications.)
224 </entry><entry>none</entry></row>
226 databaseName</entry><entry>One or more database names
227 separated by character plus (<literal>+</literal>), which to
228 be used by subsequent search requests on this Connection.
229 </entry><entry>Default</entry></row>
231 piggyback</entry><entry>True (1) if piggyback should be
232 used in searches; false (0) if not.
233 </entry><entry>1</entry></row>
235 smallSetUpperBound</entry><entry>If hits is less than or equal to this
236 value, then target will return all records using small element set name
237 </entry><entry>0</entry></row>
239 largeSetLowerBound</entry><entry>If hits is greater than this
240 value, the target will return no records.
241 </entry><entry>1</entry></row>
243 mediumSetPresentNumber</entry><entry>This value represents
244 the number of records to be returned as part of a search when when
245 hits is less than or equal to large set lower bound and if hits
246 is greater than small set upper bound.
247 </entry><entry>0</entry></row>
249 smallSetElementSetName</entry><entry>
250 The element set name to be used for small result sets.
251 </entry><entry>none</entry></row>
253 mediumSetElementSetName</entry><entry>
254 The element set name to be for medium-sized result sets.
255 </entry><entry>none</entry></row>
260 If either option <literal>lang</literal> or <literal>charset</literal>
262 <ulink url="&url.z39.50.charneg;">
263 Character Set and Language Negotiation</ulink> is in effect.
266 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
267 const char **addinfo);
268 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
269 const char **addinfo, const char **dset);
272 Function <function>ZOOM_connection_error</function> checks for
273 errors for the last operation(s) performed. The function returns
274 zero if no errors occurred; non-zero otherwise indicating the error.
275 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
276 holds messages for the error and additional-info if passed as
277 non-<literal>NULL</literal>. Function
278 <function>ZOOM_connection_error_x</function> is an extended version
279 of <function>ZOOM_connection_error</function> that is capable of
280 returning name of diagnostic set in <parameter>dset</parameter>.
282 <sect2 id="zoom-connection-z39.50">
283 <title>Z39.50 Protocol behavior</title>
285 The calls <function>ZOOM_connection_new</function> and
286 <function>ZOOM_connection_connect</function> establishes a TCP/IP
287 connection and sends an Initialize Request to the target if
288 possible. In addition, the calls waits for an Initialize Response
289 from the target and the result is inspected (OK or rejected).
292 If <literal>proxy</literal> is set then the client will establish
293 a TCP/IP connection with the peer as specified by the
294 <literal>proxy</literal> host and the hostname as part of the
295 connect calls will be set as part of the Initialize Request.
296 The proxy server will then "forward" the PDU's transparently
297 to the target behind the proxy.
300 For the authentication parameters, if option <literal>user</literal>
301 is set and both options <literal>group</literal> and
302 <literal>pass</literal> are unset, then Open style
303 authentication is used (Version 2/3) in which case the username
304 is usually followed by a slash, then by a password.
305 If either <literal>group</literal>
306 or <literal>pass</literal> is set then idPass authentication
307 (Version 3 only) is used. If none of the options are set, no
308 authentication parameters are set as part of the Initialize Request
312 When option <literal>async</literal> is 1, it really means that
313 all network operations are postponed (and queued) until the
314 function <literal>ZOOM_event</literal> is invoked. When doing so
315 it doesn't make sense to check for errors after
316 <literal>ZOOM_connection_new</literal> is called since that
317 operation "connecting - and init" is still incomplete and the
318 API cannot tell the outcome (yet).
321 <sect2><title>SRU Protocol behavior</title>
323 The SRU protocol doesn't feature an Inititialize Request, so
324 the connection phase merely establishes a TCP/IP connection
325 with the SOAP service.
327 <para>Most of the ZOOM connection options do not
328 affect SRU and they are ignored. However, future versions
329 of &yaz; might honor <literal>implementationName</literal> and
330 put that as part of User-Agent header for HTTP requests.
333 The <literal>charset</literal> is used in the Content-Type header
338 <sect1 id="zoom.query"><title>Queries</title>
340 Query objects represents queries.
343 ZOOM_query ZOOM_query_create(void);
345 void ZOOM_query_destroy(ZOOM_query q);
347 int ZOOM_query_prefix(ZOOM_query q, const char *str);
349 int ZOOM_query_cql(ZOOM_query s, const char *str);
351 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
354 Create query objects using <function>ZOOM_query_create</function>
355 and destroy them by calling <function>ZOOM_query_destroy</function>.
356 RPN-queries can be specified in <link linkend="PQF">PQF</link>
357 notation by using the
358 function <function>ZOOM_query_prefix</function>.
359 The <function>ZOOM_query_cql</function> specifies a CQL
360 query to be sent to the server/target.
361 More query types will be added in future versions of &yaz;, such as
362 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
363 etc. In addition to a search, a sort criteria may be set. Function
364 <function>ZOOM_query_sortby</function> specifies a
365 sort criteria using the same string notation for sort as offered by
366 the <link linkend="sortspec">YAZ client</link>.
368 <sect2><title>Protocol behavior</title>
370 The query object is just an interface for the member Query
371 in the SearchRequest. The sortby-function is an interface to the
372 sortSequence member of the SortRequest.
376 <sect1 id="zoom.resultsets"><title>Result sets</title>
378 The result set object is a container for records returned from
382 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
385 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
388 void ZOOM_resultset_destroy(ZOOM_resultset r);
391 Function <function>ZOOM_connection_search</function> creates
392 a result set given a connection and query.
393 Destroy a result set by calling
394 <function>ZOOM_resultset_destroy</function>.
395 Simple clients may using PQF only may use function
396 <function>ZOOM_connection_search_pqf</function> in which case
397 creating query objects is not necessary.
400 void ZOOM_resultset_option_set (ZOOM_resultset r,
404 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
407 size_t ZOOM_resultset_size (ZOOM_resultset r);
410 Functions <function>ZOOM_resultset_options_set</function> and
411 <function>ZOOM_resultset_get</function> sets and gets an option
412 for a result set similar to <function>ZOOM_connection_option_get</function>
413 and <function>ZOOM_connection_option_set</function>.
416 The number of hits also called result-count is returned by
417 function <function>ZOOM_resultset_size</function>.
419 <table frame="top"><title>ZOOM Result set Options</title>
421 <colspec colwidth="4*" colname="name"></colspec>
422 <colspec colwidth="7*" colname="description"></colspec>
423 <colspec colwidth="2*" colname="default"></colspec>
426 <entry>Option</entry>
427 <entry>Description</entry>
428 <entry>Default</entry>
433 start</entry><entry>Offset of first record to be
434 retrieved from target. First record has offset 0 unlike the
435 protocol specifications where first record has position 1.
436 </entry><entry>0</entry></row>
438 count</entry><entry>Number of records to be retrieved.
439 </entry><entry>0</entry></row>
441 presentChunk</entry><entry>The number of records to be
442 requested from the server in each chunk (present requst). The
443 value 0 means to request all the records in a single chunk.
444 (The old <literal>step</literal>
445 option is also supported for the benefit of old applications.)
446 </entry><entry>0</entry></row>
448 elementSetName</entry><entry>Element-Set name of records.
449 Most targets should honor element set name <literal>B</literal>
450 and <literal>F</literal> for brief and full respectively.
451 </entry><entry>none</entry></row>
453 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
454 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
455 </entry><entry>none</entry></row>
457 schema</entry><entry>Schema for retrieval, such as
458 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
459 </entry><entry>none</entry></row>
461 setname</entry><entry>Name of Result Set (Result Set ID).
462 If this option isn't set, the ZOOM module will automatically
463 allocate a result set name.
464 </entry><entry>default</entry></row>
469 For servers that support Search Info report, the following
470 options may be read using <function>ZOOM_resultset_get</function>.
471 This detailed information is read after a successful search has
475 This information is a list of of items, where each item is
476 information about a term or subquery. All items in the list
478 <literal>SearchResult.</literal><replaceable>no</replaceable>
479 where no presents the item number (0=first, 1=second).
480 Read <literal>searchresult.size</literal> to determine the
483 <table frame="top"><title>Search Info Report options</title>
485 <colspec colwidth="4*" colname="name"></colspec>
486 <colspec colwidth="7*" colname="description"></colspec>
489 <entry>Option</entry>
490 <entry>Description</entry>
495 <entry>searchresult.size</entry>
497 number of search result entries. This option is-nonexistant
498 if no entries are returned by the server.
502 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
503 <entry>sub query ID</entry>
506 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
507 <entry>result count for item (number of hits)</entry>
510 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
511 <entry>subquery term</entry>
515 searchresult.<replaceable>no</replaceable>.interpretation.term
517 <entry>interpretation term</entry>
521 searchresult.<replaceable>no</replaceable>.recommendation.term
523 <entry>recommendation term</entry>
529 <title>Z39.50 Protocol behavior</title>
531 The creation of a result set involves at least a SearchRequest
532 - SearchResponse protocol handshake. Following that, if a sort
533 criteria was specified as part of the query, a SortRequest -
534 SortResponse handshake takes place. Note that it is necessary to
535 perform sorting before any retrieval takes place, so no records will
536 be returned from the target as part of the SearchResponse because these
537 would be unsorted. Hence, piggyback is disabled when sort criteria
538 are set. Following Search - and a possible sort - Retrieval takes
539 place - as one or more Present Requests/Response pairs being
543 The API allows for two different modes for retrieval. A high level
544 mode which is somewhat more powerful and a low level one.
545 The low level is enabled when searching on a Connection object
546 for which the settings
547 <literal>smallSetUpperBound</literal>,
548 <literal>mediumSetPresentNumber</literal> and
549 <literal>largeSetLowerBound</literal> are set. The low level mode
550 thus allows you to precisely set how records are returned as part
551 of a search response as offered by the Z39.50 protocol.
552 Since the client may be retrieving records as part of the
553 search response, this mode doesn't work well if sorting is used.
556 The high-level mode allows you to fetch a range of records from
557 the result set with a given start offset. When you use this mode
558 the client will automatically use piggyback if that is possible
559 with the target and perform one or more present requests as needed.
560 Even if the target returns fewer records as part of a present response
561 because of a record size limit, etc. the client will repeat sending
562 present requests. As an example, if option <literal>start</literal>
563 is 0 (default) and <literal>count</literal> is 4, and
564 <literal>piggyback</literal> is 1 (default) and no sorting criteria
565 is specified, then the client will attempt to retrieve the 4
566 records as part the search response (using piggyback). On the other
567 hand, if either <literal>start</literal> is positive or if
568 a sorting criteria is set, or if <literal>piggyback</literal>
569 is 0, then the client will not perform piggyback but send Present
573 If either of the options <literal>mediumSetElementSetName</literal> and
574 <literal>smallSetElementSetName</literal> are unset, the value
575 of option <literal>elementSetName</literal> is used for piggyback
576 searches. This means that for the high-level mode you only have
577 to specify one elementSetName option rather than three.
581 <title>SRU Protocol behavior</title>
583 Current version of &yaz; does not take advantage of a result set id
584 returned by the SRU server. Future versions might do, however.
585 Since, the ZOOM driver does not save result set IDs any
586 present (retrieval) is transformed to a SRU SearchRetrieveRequest
587 with same query but, possibly, different offsets.
590 Option <literal>schema</literal> specifies SRU schema
591 for retrieval. However, options <literal>elementSetName</literal> and
592 <literal>preferredRecordSyntax</literal> are ignored.
595 Options <literal>start</literal> and <literal>count</literal>
596 are supported by SRU.
597 The remaining options
598 <literal>piggyback</literal>,
599 <literal>smallSetUpperBound</literal>,
600 <literal>largeSetLowerBound</literal>,
601 <literal>mediumSetPresentNumber</literal>,
602 <literal>mediumSetElementSetName</literal>,
603 <literal>smallSetElementSetName</literal> are
607 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
608 If PQF is used, however, the PQF query is transferred anyway
609 using non-standard element <literal>pQuery</literal> in
610 SRU SearchRetrieveRequest.
613 Unfortunately, SRU does not define a database setting. Hence,
614 <literal>databaseName</literal> is unsupported and ignored.
615 However, the path part in host parameter for functions
616 <function>ZOOM_connecton_new</function> and
617 <function>ZOOM_connection_connect</function> acts as a
618 database (at least for the &yaz; SRU server).
622 <sect1 id="zoom.records"><title>Records</title>
624 A record object is a retrieval record on the client side -
625 created from result sets.
628 void ZOOM_resultset_records (ZOOM_resultset r,
630 size_t start, size_t count);
631 ZOOM_record ZOOM_resultset_record (ZOOM_resultset s, size_t pos);
633 const char *ZOOM_record_get (ZOOM_record rec, const char *type,
636 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
638 void ZOOM_record_destroy (ZOOM_record rec);
641 References to temporary records are returned by functions
642 <function>ZOOM_resultset_records</function> or
643 <function>ZOOM_resultset_record</function>.
646 If a persistent reference to a record is desired
647 <function>ZOOM_record_clone</function> should be used.
648 It returns a record reference that should be destroyed
649 by a call to <function>ZOOM_record_destroy</function>.
652 A single record is returned by function
653 <function>ZOOM_resultset_record</function> that takes a
654 position as argument. First record has position zero.
655 If no record could be obtained <literal>NULL</literal> is returned.
658 Function <function>ZOOM_resultset_records</function> retrieves
659 a number of records from a result set. Parameter <literal>start</literal>
660 and <literal>count</literal> specifies the range of records to
661 be returned. Upon completion array
662 <literal>recs[0], ..recs[count-1]</literal>
663 holds record objects for the records. The array of records
664 <literal>recs</literal> should be allocated prior the call
665 <function>ZOOM_resultset_records</function>. Note that for those
666 records that couldn't be retrieved from the target
667 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
669 <para id="zoom.record.get">
670 In order to extract information about a single record,
671 <function>ZOOM_record_get</function> is provided. The
672 function returns a pointer to certain record information. The
673 nature (type) of the pointer depends on the parameter,
674 <parameter>type</parameter>.
677 The <parameter>type</parameter> is a string of the format:
680 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
683 where <replaceable>form</replaceable> specifies the format of the
684 returned record, <replaceable>from</replaceable>
685 specifies the character set of the record in its original form
686 (as returned by the server), <replaceable>to</replaceable> specifies
687 the output (returned)
688 character set encoding.
689 If charset is not given, then no character set conversion takes place.
690 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
693 In addition, for certain types, the length
694 <literal>len</literal> passed will be set to the size in bytes of
695 the returned information.
698 The following are the supported values for <replaceable>form</replaceable>.
700 <varlistentry><term><literal>database</literal></term>
701 <listitem><para>Database of record is returned
702 as a C null-terminated string. Return type
703 <literal>const char *</literal>.
706 <varlistentry><term><literal>syntax</literal></term>
707 <listitem><para>The transfer syntax of the record is returned
708 as a C null-terminated string containing the symbolic name of
709 the record syntax, e.g. <literal>Usmarc</literal>. Return type
711 <literal>const char *</literal>.
714 <varlistentry><term><literal>render</literal></term>
715 <listitem><para>The record is returned in a display friendly
716 format. Upon completion buffer is returned
717 (type <literal>const char *</literal>) and length is stored in
718 <literal>*len</literal>.
721 <varlistentry><term><literal>raw</literal></term>
722 <listitem><para>The record is returned in the internal
723 YAZ specific format. For GRS-1, Explain, and others, the
724 raw data is returned as type
725 <literal>Z_External *</literal> which is just the type for
726 the member <literal>retrievalRecord</literal> in
727 type <literal>NamePlusRecord</literal>.
728 For SUTRS and octet aligned record (including all MARCs) the
729 octet buffer is returned and the length of the buffer.
732 <varlistentry><term><literal>xml</literal></term>
733 <listitem><para>The record is returned in XML if possible.
734 SRU and Z39.50 records with transfer syntax XML are
735 returned verbatim. MARC records are returned in
736 <ulink url="&url.marcxml;">
739 (converted from ISO2709 to MARCXML by YAZ).
740 GRS-1 and OPAC records are not supported for this form.
741 Upon completion, the XML buffer is returned
742 (type <literal>const char *</literal>) and length is stored in
743 <literal>*len</literal>.
746 <varlistentry><term><literal>opac</literal></term>
747 <listitem><para>OPAC for record is returned in XML.
754 <ulink url="&url.marc21;">MARC21</ulink>
756 <ulink url="&url.marc8;">MARC-8</ulink>
757 character set encoding.
758 An application that wishes to display in Latin-1 would use
760 render; charset=marc8,iso-8859-1
763 <sect2><title>Z39.50 Protocol behavior</title>
765 The functions <function>ZOOM_resultset_record</function> and
766 <function>ZOOM_resultset_records</function> inspects the client-side
767 record cache. Records not found in cache are fetched using
769 The functions may block (and perform network I/O) - even though option
770 <literal>async</literal> is 1, because they return records objects.
771 (and there's no way to return records objects without retrieving them!).
774 There is a trick, however, in the usage of function
775 <function>ZOOM_resultset_records</function> that allows for
776 delayed retrieval (and makes it non-blocking). By using
777 a null pointer for <parameter>recs</parameter> you're indicating
778 you're not interested in getting records objects
779 <emphasis>now</emphasis>.
782 <sect2><title>SRU Protocol behavior</title>
784 The ZOOM driver for SRU treats records returned by a SRU server
785 as if they where Z39.50 records with transfer syntax XML and
786 no element set name or database name.
790 <sect1 id="zoom.scan"><title>Scan</title>
792 This section describes an interface for Scan. Scan is not an
793 official part of the ZOOM model yet. The result of a scan operation
794 is the <literal>ZOOM_scanset</literal> which is a set of terms
795 returned by a target.
799 The Scan interface is Z39.50 only. SRW version 1.0 does not
804 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
805 const char *startpqf);
807 size_t ZOOM_scanset_size(ZOOM_scanset scan);
809 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
810 int *occ, size_t *len);
812 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
813 int *occ, size_t *len);
815 void ZOOM_scanset_destroy (ZOOM_scanset scan);
817 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
820 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
824 The scan set is created by function
825 <function>ZOOM_connection_scan</function> which performs a scan
826 operation on the connection using the specified
827 <parameter>startpqf</parameter>.
828 If the operation was successful, the size of the scan set can be
829 retrieved by a call to <function>ZOOM_scanset_size</function>.
830 Like result sets, the items are numbered 0,..size-1.
831 To obtain information about a particular scan term, call function
832 <function>ZOOM_scanset_term</function>. This function takes
833 a scan set offset <literal>pos</literal> and returns a pointer
834 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
836 If present, the <literal>occ</literal> and <literal>len</literal>
837 are set to the number of occurrences and the length
838 of the actual term respectively.
839 <function>ZOOM_scanset_display_term</function> is similar to
840 <function>ZOOM_scanset_term</function> except that it returns
841 the <emphasis>display term</emphasis> rather than the raw term.
842 In a few cases, the term is different from display term. Always
843 use the display term for display and the raw term for subsequent
844 scan operations (to get more terms, next scan result, etc).
847 A scan set may be freed by a call to function
848 <function>ZOOM_scanset_destroy</function>.
849 Functions <function>ZOOM_scanset_option_get</function> and
850 <function>ZOOM_scanset_option_set</function> retrieves and sets
851 an option respectively.
855 The <parameter>startpqf</parameter> is a subset of PQF, namely
856 the Attributes+Term part. Multiple <literal>@attr</literal> can
857 be used. For example to scan in title (complete) phrases:
859 @attr 1=4 @attr 6=2 "science o"
863 <table frame="top"><title>ZOOM Scan Set Options</title>
865 <colspec colwidth="4*" colname="name"></colspec>
866 <colspec colwidth="7*" colname="description"></colspec>
867 <colspec colwidth="2*" colname="default"></colspec>
870 <entry>Option</entry>
871 <entry>Description</entry>
872 <entry>Default</entry>
877 number</entry><entry>Number of Scan Terms requested in next scan.
878 After scan it holds the actual number of terms returned.
879 </entry><entry>10</entry></row>
881 position</entry><entry>Preferred Position of term in response
882 in next scan; actual position after completion of scan.
883 </entry><entry>1</entry></row>
885 stepSize</entry><entry>Step Size
886 </entry><entry>0</entry></row>
888 scanStatus</entry><entry>An integer indicating the Scan Status
890 </entry><entry>0</entry></row>
896 <sect1 id="zoom.ext"><title>Extended Services</title>
898 ZOOM offers an interface to a subset of the Z39.50 extended services
899 as well as a few privately defined ones:
904 Z39.50 Item Order (ILL).
905 See <xref linkend="zoom.ext.itemorder"/>.
910 Record Update. This allows a client to insert, modify or delete
912 See <xref linkend="zoom.ext.update"/>.
917 Database Create. This a non-standard feature. Allows a client
918 to create a database.
919 See <xref linkend="zoom.ext.dbcreate"/>.
924 Database Drop. This a non-standard feature. Allows a client
925 to delete/drop a database.
926 See <xref linkend="zoom.ext.dbdrop"/>.
931 Commit operation. This a non-standard feature. Allows a client
932 to commit operations.
933 See <xref linkend="zoom.ext.commit"/>.
936 <!-- all the ILL PDU options should go here too -->
939 To create an extended service operation a <literal>ZOOM_package</literal>
940 must be created. The operation is a five step operation. The
941 package is created, package is configured by means of options,
942 the package is send, result is inspected (by means of options),
943 the package is destroyed.
946 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
947 ZOOM_options options);
949 const char *ZOOM_package_option_get(ZOOM_package p,
951 void ZOOM_package_option_set(ZOOM_package p, const char *key,
953 void ZOOM_package_send(ZOOM_package p, const char *type);
955 void ZOOM_package_destroy(ZOOM_package p);
958 The <function>ZOOM_connection_package</function> creates a
959 package for the connection given using the options specified.
962 Functions <function>ZOOM_package_option_get</function> and
963 <function>ZOOM_package_option_set</function> gets and sets
967 <function>ZOOM_package_send</function> sends
968 the package the via connection specified in
969 <function>ZOOM_connection_package</function>.
970 The <parameter>type</parameter> specifies the actual extended service
971 package type to be sent.
974 <table frame="top"><title>Extended Service Common Options</title>
976 <colspec colwidth="4*" colname="name"></colspec>
977 <colspec colwidth="7*" colname="description"></colspec>
978 <colspec colwidth="3*" colname="default"></colspec>
981 <entry>Option</entry>
982 <entry>Description</entry>
983 <entry>Default</entry>
988 <entry>package-name</entry>
989 <entry>Extended Service Request package name. Must be specified
990 as part of a request</entry>
994 <entry>user-id</entry>
995 <entry>User ID of Extended Service Package. Is a request option</entry>
999 <entry>function</entry>
1001 Function of package - one of <literal>create</literal>,
1002 <literal>delete</literal>, <literal>modify</literal>. Is
1005 <entry><literal>create</literal></entry>
1008 <entry>targetReference</entry>
1010 Target Reference. This is part of the response as returned
1011 by the server. Read it after a succesful operation.
1013 <entry><literal>none</literal></entry>
1019 <sect2 id="zoom.ext.itemorder"><title>Item Order</title>
1021 For Item Order, type must be set to <literal>itemorder</literal> in
1022 <function>ZOOM_package_send</function>.
1025 <table frame="top"><title>Item Order Options</title>
1027 <colspec colwidth="4*" colname="name"></colspec>
1028 <colspec colwidth="7*" colname="description"></colspec>
1029 <colspec colwidth="3*" colname="default"></colspec>
1032 <entry>Option</entry>
1033 <entry>Description</entry>
1034 <entry>Default</entry>
1039 <entry>contact-name</entry>
1040 <entry>ILL contact name</entry>
1044 <entry>contact-phone</entry>
1045 <entry>ILL contact phone</entry>
1049 <entry>contact-email</entry>
1050 <entry>ILL contact email</entry>
1054 <entry>itemorder-item</entry>
1055 <entry>Position for item (record) requested. An integer</entry>
1064 <sect2 id="zoom.ext.update"><title>Record Update</title>
1066 For Record Update, type must be set to <literal>update</literal> in
1067 <function>ZOOM_package_send</function>.
1070 <table frame="top"><title>Record Update Options</title>
1072 <colspec colwidth="4*" colname="name"></colspec>
1073 <colspec colwidth="7*" colname="description"></colspec>
1074 <colspec colwidth="3*" colname="default"></colspec>
1077 <entry>Option</entry>
1078 <entry>Description</entry>
1079 <entry>Default</entry>
1084 <entry>action</entry>
1086 The update action. One of
1087 <literal>specialUpdate</literal>,
1088 <literal>recordInsert</literal>,
1089 <literal>recordReplace</literal>,
1090 <literal>recordDelete</literal>,
1091 <literal>elementUpdate</literal>.
1093 <entry><literal>specialUpdate</literal></entry>
1096 <entry>recordIdOpaque</entry>
1097 <entry>Opaque Record ID</entry>
1101 <entry>recordIdNumber</entry>
1102 <entry>Record ID number</entry>
1106 <entry>record</entry>
1107 <entry>The record itself</entry>
1111 <entry>syntax</entry>
1112 <entry>The record syntax (transfer syntax). Is a string that
1113 is a known record syntax.
1115 <entry>no syntax</entry>
1118 <entry>databaseName</entry>
1119 <entry>Database from connection object</entry>
1120 <entry>Default</entry>
1128 <sect2 id="zoom.ext.dbcreate"><title>Database Create</title>
1130 For Database Create, type must be set to <literal>create</literal> in
1131 <function>ZOOM_package_send</function>.
1134 <table frame="top"><title>Database Create Options</title>
1136 <colspec colwidth="4*" colname="name"></colspec>
1137 <colspec colwidth="7*" colname="description"></colspec>
1138 <colspec colwidth="3*" colname="default"></colspec>
1141 <entry>Option</entry>
1142 <entry>Description</entry>
1143 <entry>Default</entry>
1148 <entry>databaseName</entry>
1149 <entry>Database from connection object</entry>
1150 <entry>Default</entry>
1157 <sect2 id="zoom.ext.dbdrop"><title>Database Drop</title>
1159 For Database Drop, type must be set to <literal>drop</literal> in
1160 <function>ZOOM_package_send</function>.
1163 <table frame="top"><title>Database Create Options</title>
1165 <colspec colwidth="4*" colname="name"></colspec>
1166 <colspec colwidth="7*" colname="description"></colspec>
1167 <colspec colwidth="3*" colname="default"></colspec>
1170 <entry>Option</entry>
1171 <entry>Description</entry>
1172 <entry>Default</entry>
1177 <entry>databaseName</entry>
1178 <entry>Database from connection object</entry>
1179 <entry>Default</entry>
1186 <sect2 id="zoom.ext.commit"><title>Commit Operation</title>
1188 For Commit, type must be set to <literal>commit</literal> in
1189 <function>ZOOM_package_send</function>.
1193 <sect2><title>Protocol behavior</title>
1195 All the extended services are Z39.50-only.
1199 The database create, drop and commit services are privately defined
1201 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1208 <sect1 id="zoom.options"><title>Options</title>
1210 Most &zoom; objects provide a way to specify options to change behavior.
1211 From an implementation point of view a set of options is just like
1212 an associative array / hash.
1215 ZOOM_options ZOOM_options_create (void);
1217 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1219 void ZOOM_options_destroy (ZOOM_options opt);
1222 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1224 void ZOOM_options_set (ZOOM_options opt, const char *name,
1228 typedef const char *(*ZOOM_options_callback)
1229 (void *handle, const char *name);
1231 ZOOM_options_callback
1232 ZOOM_options_set_callback (ZOOM_options opt,
1233 ZOOM_options_callback c,
1237 <sect1 id="zoom.events"><title>Events</title>
1239 If you're developing non-blocking applications, you have to deal
1243 int ZOOM_event (int no, ZOOM_connection *cs);
1246 The <function>ZOOM_event</function> executes pending events for
1247 a number of connections. Supply the number of connections in
1248 <literal>no</literal> and an array of connections in
1249 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1250 A pending event could be a sending a search, receiving a response,
1252 When an event has occurred for one of the connections, this function
1253 returns a positive integer <literal>n</literal> denoting that an event
1254 occurred for connection <literal>cs[n-1]</literal>.
1255 When no events are pending for the connections, a value of zero is
1257 To ensure that all outstanding requests are performed call this function
1258 repeatedly until zero is returned.
1261 If <function>ZOOM_event</function> returns and returns non-zero, the
1262 last event that occurred can be expected.
1265 int ZOOM_connection_last_event(ZOOM_connection cs);
1268 <function>ZOOM_connection_last_event</function> returns an event type
1269 (integer) for the last event.
1272 <table frame="top"><title>ZOOM Event IDs</title>
1274 <colspec colwidth="4*" colname="name"></colspec>
1275 <colspec colwidth="7*" colname="description"></colspec>
1278 <entry>Event</entry>
1279 <entry>Description</entry>
1284 <entry>ZOOM_EVENT_NONE</entry>
1285 <entry>No event has occurred</entry>
1288 <entry>ZOOM_EVENT_CONNECT</entry>
1289 <entry>TCP/IP connect has initiated</entry>
1292 <entry>ZOOM_EVENT_SEND_DATA</entry>
1293 <entry>Data has been transmitted (sending)</entry>
1296 <entry>ZOOM_EVENT_RECV_DATA</entry>
1297 <entry>Data has been received)</entry>
1300 <entry>ZOOM_EVENT_TIMEOUT</entry>
1301 <entry>Timeout</entry>
1304 <entry>ZOOM_EVENT_UNKNOWN</entry>
1305 <entry>Unknown event</entry>
1308 <entry>ZOOM_EVENT_SEND_APDU</entry>
1309 <entry>An APDU has been transmitted (sending)</entry>
1312 <entry>ZOOM_EVENT_RECV_APDU</entry>
1313 <entry>An APDU has been received</entry>
1316 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1317 <entry>A result-set record has been received</entry>
1320 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1321 <entry>A search result been received</entry>
1329 <!-- Keep this comment at the end of the file
1334 sgml-minimize-attributes:nil
1335 sgml-always-quote-attributes:t
1338 sgml-parent-document: "yaz.xml"
1339 sgml-local-catalogs: nil
1340 sgml-namecase-general:t