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 1.54 2006-10-31 14:08:01 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. The dialect of SRU used is
38 specified by the value of the connection's <literal>sru</literal>
39 option, which may be SRU over HTTP GET (<literal>get</literal>),
40 SRU over HTTP POST (<literal>post</literal>) or SRW (SRU over
41 SOAP) (<literal>soap</literal>).
46 The lack of a simple Z39.50 client API for &yaz; has become more
47 and more apparent over time. So when the first &zoom; specification
49 an implementation for &yaz; was quickly developed. For the first time, it is
50 now as easy (or easier!) to develop clients than servers with &yaz;. This
51 chapter describes the &zoom; C binding. Before going further, please
52 reconsider whether C is the right programming language for the job.
53 There are other language bindings available for &yaz;, and still
55 are in active development. See the
56 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
61 In order to fully understand this chapter you should read and
62 try the example programs <literal>zoomtst1.c</literal>,
63 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
68 The C language misses features found in object oriented languages
69 such as C++, Java, etc. For example, you'll have to manually,
70 destroy all objects you create, even though you may think of them as
71 temporary. Most objects has a <literal>_create</literal> - and a
72 <literal>_destroy</literal> variant.
73 All objects are in fact pointers to internal stuff, but you don't see
74 that because of typedefs. All destroy methods should gracefully ignore a
75 <literal>NULL</literal> pointer.
78 In each of the sections below you'll find a sub section called
79 protocol behavior, that describes how the API maps to the Z39.50
82 <sect1 id="zoom-connections"><title>Connections</title>
84 <para>The Connection object is a session with a target.
87 #include <yaz/zoom.h>
89 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
91 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
93 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
95 void ZOOM_connection_destroy (ZOOM_connection c);
98 Connection objects are created with either function
99 <function>ZOOM_connection_new</function> or
100 <function>ZOOM_connection_create</function>.
101 The former creates and automatically attempts to establish a network
102 connection with the target. The latter doesn't establish
103 a connection immediately, thus allowing you to specify options
104 before establishing network connection using the function
105 <function>ZOOM_connection_connect</function>.
106 If the port number, <literal>portnum</literal>, is zero, the
107 <literal>host</literal> is consulted for a port specification.
108 If no port is given, 210 is used. A colon denotes the beginning of
109 a port number in the host string. If the host string includes a
110 slash, the following part specifies a database for the connection.
113 You can prefix the host with a scheme followed by colon. The
114 default scheme is <literal>tcp</literal> (Z39.50 protocol).
115 The scheme <literal>http</literal> selects SRU over HTTP.
118 You can prefix the scheme-qualified host-string with one or more
120 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
121 sequences, each of which represents an option to be set into the
122 connection structure <emphasis>before</emphasis> the
123 protocol-level connection is forged and the initialisation
124 handshake takes place. This facility can be used to provide
125 authentication credentials, as in host-strings such as:
126 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
129 Connection objects should be destroyed using the function
130 <function>ZOOM_connection_destroy</function>.
133 void ZOOM_connection_option_set(ZOOM_connection c,
134 const char *key, const char *val);
136 void ZOOM_connection_option_setl(ZOOM_connection c,
138 const char *val, int len);
140 const char *ZOOM_connection_option_get(ZOOM_connection c,
142 const char *ZOOM_connection_option_getl(ZOOM_connection c,
147 The functions <function>ZOOM_connection_option_set</function> and
148 <function>ZOOM_connection_option_setl</function> allows you to
149 set an option given by <parameter>key</parameter> to the value
150 <parameter>value</parameter> for the connection.
151 For <function>ZOOM_connection_option_set</function>, the
152 value is assumed to be a 0-terminated string. Function
153 <function>ZOOM_connection_option_setl</function> specifies a
154 value of a certain size (len).
157 Functions <function>ZOOM_connection_option_get</function> and
158 <function>ZOOM_connection_option_getl</function> returns
159 the value for an option given by <parameter>key</parameter>.
161 <table id="zoom-connection-options" frame="top">
162 <title>ZOOM Connection Options</title>
164 <colspec colwidth="4*" colname="name"></colspec>
165 <colspec colwidth="7*" colname="description"></colspec>
166 <colspec colwidth="3*" colname="default"></colspec>
169 <entry>Option</entry>
170 <entry>Description</entry>
171 <entry>Default</entry>
176 implementationName</entry><entry>Name of Your client
177 </entry><entry>none</entry></row>
179 user</entry><entry>Authentication user name
180 </entry><entry>none</entry></row>
182 group</entry><entry>Authentication group name
183 </entry><entry>none</entry></row>
185 password</entry><entry>Authentication password.
186 </entry><entry>none</entry></row>
188 host</entry><entry>Target host. This setting is "read-only".
189 It's automatically set internally when connecting to a target.
190 </entry><entry>none</entry></row>
192 proxy</entry><entry>Proxy host
193 </entry><entry>none</entry></row>
195 async</entry><entry>If true (1) the connection operates in
196 asynchronous operation which means that all calls are non-blocking
198 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
199 </entry><entry>0</entry></row>
201 maximumRecordSize</entry><entry> Maximum size of single record.
202 </entry><entry>1 MB</entry></row>
204 preferredMessageSize</entry><entry> Maximum size of multiple records.
205 </entry><entry>1 MB</entry></row>
207 lang</entry><entry> Language for negotiation.
208 </entry><entry>none</entry></row>
210 charset</entry><entry> Character set for negotiation.
211 </entry><entry>none</entry></row>
213 serverImplementationId</entry><entry>
214 Implementation ID of server. (The old targetImplementationId
215 option is also supported for the benefit of old applications.)
216 </entry><entry>none</entry></row>
218 targetImplementationName</entry><entry>
219 Implementation Name of server. (The old
220 targetImplementationName option is also supported for the
221 benefit of old applications.)
222 </entry><entry>none</entry></row>
224 serverImplementationVersion</entry><entry>
225 Implementation Version of server. (the old
226 targetImplementationVersion option is also supported for the
227 benefit of old applications.)
228 </entry><entry>none</entry></row>
230 databaseName</entry><entry>One or more database names
231 separated by character plus (<literal>+</literal>), which to
232 be used by subsequent search requests on this Connection.
233 </entry><entry>Default</entry></row>
235 piggyback</entry><entry>True (1) if piggyback should be
236 used in searches; false (0) if not.
237 </entry><entry>1</entry></row>
239 smallSetUpperBound</entry><entry>If hits is less than or equal to this
240 value, then target will return all records using small element set name
241 </entry><entry>0</entry></row>
243 largeSetLowerBound</entry><entry>If hits is greater than this
244 value, the target will return no records.
245 </entry><entry>1</entry></row>
247 mediumSetPresentNumber</entry><entry>This value represents
248 the number of records to be returned as part of a search when when
249 hits is less than or equal to large set lower bound and if hits
250 is greater than small set upper bound.
251 </entry><entry>0</entry></row>
253 smallSetElementSetName</entry><entry>
254 The element set name to be used for small result sets.
255 </entry><entry>none</entry></row>
257 mediumSetElementSetName</entry><entry>
258 The element set name to be for medium-sized result sets.
259 </entry><entry>none</entry></row>
264 If either option <literal>lang</literal> or <literal>charset</literal>
266 <ulink url="&url.z39.50.charneg;">
267 Character Set and Language Negotiation</ulink> is in effect.
270 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
271 const char **addinfo);
272 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
273 const char **addinfo, const char **dset);
276 Function <function>ZOOM_connection_error</function> checks for
277 errors for the last operation(s) performed. The function returns
278 zero if no errors occurred; non-zero otherwise indicating the error.
279 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
280 holds messages for the error and additional-info if passed as
281 non-<literal>NULL</literal>. Function
282 <function>ZOOM_connection_error_x</function> is an extended version
283 of <function>ZOOM_connection_error</function> that is capable of
284 returning name of diagnostic set in <parameter>dset</parameter>.
286 <sect2 id="zoom-connection-z39.50">
287 <title>Z39.50 Protocol behavior</title>
289 The calls <function>ZOOM_connection_new</function> and
290 <function>ZOOM_connection_connect</function> establishes a TCP/IP
291 connection and sends an Initialize Request to the target if
292 possible. In addition, the calls waits for an Initialize Response
293 from the target and the result is inspected (OK or rejected).
296 If <literal>proxy</literal> is set then the client will establish
297 a TCP/IP connection with the peer as specified by the
298 <literal>proxy</literal> host and the hostname as part of the
299 connect calls will be set as part of the Initialize Request.
300 The proxy server will then "forward" the PDU's transparently
301 to the target behind the proxy.
304 For the authentication parameters, if option <literal>user</literal>
305 is set and both options <literal>group</literal> and
306 <literal>pass</literal> are unset, then Open style
307 authentication is used (Version 2/3) in which case the username
308 is usually followed by a slash, then by a password.
309 If either <literal>group</literal>
310 or <literal>pass</literal> is set then idPass authentication
311 (Version 3 only) is used. If none of the options are set, no
312 authentication parameters are set as part of the Initialize Request
316 When option <literal>async</literal> is 1, it really means that
317 all network operations are postponed (and queued) until the
318 function <literal>ZOOM_event</literal> is invoked. When doing so
319 it doesn't make sense to check for errors after
320 <literal>ZOOM_connection_new</literal> is called since that
321 operation "connecting - and init" is still incomplete and the
322 API cannot tell the outcome (yet).
325 <sect2 id="zoom.sru.init.behavior">
326 <title>SRU Protocol behavior</title>
328 The SRU protocol doesn't feature an Inititialize Request, so
329 the connection phase merely establishes a TCP/IP connection
330 with the SOAP service.
332 <para>Most of the ZOOM connection options do not
333 affect SRU and they are ignored. However, future versions
334 of &yaz; might honor <literal>implementationName</literal> and
335 put that as part of User-Agent header for HTTP requests.
338 The <literal>charset</literal> is used in the Content-Type header
343 <sect1 id="zoom.query"><title>Queries</title>
345 Query objects represents queries.
348 ZOOM_query ZOOM_query_create(void);
350 void ZOOM_query_destroy(ZOOM_query q);
352 int ZOOM_query_prefix(ZOOM_query q, const char *str);
354 int ZOOM_query_cql(ZOOM_query s, const char *str);
356 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
359 Create query objects using <function>ZOOM_query_create</function>
360 and destroy them by calling <function>ZOOM_query_destroy</function>.
361 RPN-queries can be specified in <link linkend="PQF">PQF</link>
362 notation by using the
363 function <function>ZOOM_query_prefix</function>.
364 The <function>ZOOM_query_cql</function> specifies a CQL
365 query to be sent to the server/target.
366 More query types will be added in future versions of &yaz;, such as
367 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
368 etc. In addition to a search, a sort criteria may be set. Function
369 <function>ZOOM_query_sortby</function> specifies a
370 sort criteria using the same string notation for sort as offered by
371 the <link linkend="sortspec">YAZ client</link>.
373 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
375 The query object is just an interface for the member Query
376 in the SearchRequest. The sortby-function is an interface to the
377 sortSequence member of the SortRequest.
381 <sect1 id="zoom.resultsets"><title>Result sets</title>
383 The result set object is a container for records returned from
387 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
390 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
393 void ZOOM_resultset_destroy(ZOOM_resultset r);
396 Function <function>ZOOM_connection_search</function> creates
397 a result set given a connection and query.
398 Destroy a result set by calling
399 <function>ZOOM_resultset_destroy</function>.
400 Simple clients may using PQF only may use function
401 <function>ZOOM_connection_search_pqf</function> in which case
402 creating query objects is not necessary.
405 void ZOOM_resultset_option_set (ZOOM_resultset r,
409 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
412 size_t ZOOM_resultset_size (ZOOM_resultset r);
415 Functions <function>ZOOM_resultset_options_set</function> and
416 <function>ZOOM_resultset_get</function> sets and gets an option
417 for a result set similar to <function>ZOOM_connection_option_get</function>
418 and <function>ZOOM_connection_option_set</function>.
421 The number of hits also called result-count is returned by
422 function <function>ZOOM_resultset_size</function>.
424 <table id="zoom.resultset.options"
425 frame="top"><title>ZOOM Result set Options</title>
427 <colspec colwidth="4*" colname="name"></colspec>
428 <colspec colwidth="7*" colname="description"></colspec>
429 <colspec colwidth="2*" colname="default"></colspec>
432 <entry>Option</entry>
433 <entry>Description</entry>
434 <entry>Default</entry>
439 start</entry><entry>Offset of first record to be
440 retrieved from target. First record has offset 0 unlike the
441 protocol specifications where first record has position 1.
442 </entry><entry>0</entry></row>
444 count</entry><entry>Number of records to be retrieved.
445 </entry><entry>0</entry></row>
447 presentChunk</entry><entry>The number of records to be
448 requested from the server in each chunk (present requst). The
449 value 0 means to request all the records in a single chunk.
450 (The old <literal>step</literal>
451 option is also supported for the benefit of old applications.)
452 </entry><entry>0</entry></row>
454 elementSetName</entry><entry>Element-Set name of records.
455 Most targets should honor element set name <literal>B</literal>
456 and <literal>F</literal> for brief and full respectively.
457 </entry><entry>none</entry></row>
459 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
460 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
461 </entry><entry>none</entry></row>
463 schema</entry><entry>Schema for retrieval, such as
464 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
465 </entry><entry>none</entry></row>
467 setname</entry><entry>Name of Result Set (Result Set ID).
468 If this option isn't set, the ZOOM module will automatically
469 allocate a result set name.
470 </entry><entry>default</entry></row>
475 For servers that support Search Info report, the following
476 options may be read using <function>ZOOM_resultset_get</function>.
477 This detailed information is read after a successful search has
481 This information is a list of of items, where each item is
482 information about a term or subquery. All items in the list
484 <literal>SearchResult.</literal><replaceable>no</replaceable>
485 where no presents the item number (0=first, 1=second).
486 Read <literal>searchresult.size</literal> to determine the
489 <table id="zoom.search.info.report.options"
490 frame="top"><title>Search Info Report Options</title>
492 <colspec colwidth="4*" colname="name"></colspec>
493 <colspec colwidth="7*" colname="description"></colspec>
496 <entry>Option</entry>
497 <entry>Description</entry>
502 <entry>searchresult.size</entry>
504 number of search result entries. This option is-nonexistant
505 if no entries are returned by the server.
509 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
510 <entry>sub query ID</entry>
513 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
514 <entry>result count for item (number of hits)</entry>
517 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
518 <entry>subquery term</entry>
522 searchresult.<replaceable>no</replaceable>.interpretation.term
524 <entry>interpretation term</entry>
528 searchresult.<replaceable>no</replaceable>.recommendation.term
530 <entry>recommendation term</entry>
535 <sect2 id="zoom.z3950.resultset.behavior">
536 <title>Z39.50 Protocol behavior</title>
538 The creation of a result set involves at least a SearchRequest
539 - SearchResponse protocol handshake. Following that, if a sort
540 criteria was specified as part of the query, a SortRequest -
541 SortResponse handshake takes place. Note that it is necessary to
542 perform sorting before any retrieval takes place, so no records will
543 be returned from the target as part of the SearchResponse because these
544 would be unsorted. Hence, piggyback is disabled when sort criteria
545 are set. Following Search - and a possible sort - Retrieval takes
546 place - as one or more Present Requests/Response pairs being
550 The API allows for two different modes for retrieval. A high level
551 mode which is somewhat more powerful and a low level one.
552 The low level is enabled when searching on a Connection object
553 for which the settings
554 <literal>smallSetUpperBound</literal>,
555 <literal>mediumSetPresentNumber</literal> and
556 <literal>largeSetLowerBound</literal> are set. The low level mode
557 thus allows you to precisely set how records are returned as part
558 of a search response as offered by the Z39.50 protocol.
559 Since the client may be retrieving records as part of the
560 search response, this mode doesn't work well if sorting is used.
563 The high-level mode allows you to fetch a range of records from
564 the result set with a given start offset. When you use this mode
565 the client will automatically use piggyback if that is possible
566 with the target and perform one or more present requests as needed.
567 Even if the target returns fewer records as part of a present response
568 because of a record size limit, etc. the client will repeat sending
569 present requests. As an example, if option <literal>start</literal>
570 is 0 (default) and <literal>count</literal> is 4, and
571 <literal>piggyback</literal> is 1 (default) and no sorting criteria
572 is specified, then the client will attempt to retrieve the 4
573 records as part the search response (using piggyback). On the other
574 hand, if either <literal>start</literal> is positive or if
575 a sorting criteria is set, or if <literal>piggyback</literal>
576 is 0, then the client will not perform piggyback but send Present
580 If either of the options <literal>mediumSetElementSetName</literal> and
581 <literal>smallSetElementSetName</literal> are unset, the value
582 of option <literal>elementSetName</literal> is used for piggyback
583 searches. This means that for the high-level mode you only have
584 to specify one elementSetName option rather than three.
587 <sect2 id="zoom.sru.resultset.behavior">
588 <title>SRU Protocol behavior</title>
590 Current version of &yaz; does not take advantage of a result set id
591 returned by the SRU server. Future versions might do, however.
592 Since, the ZOOM driver does not save result set IDs any
593 present (retrieval) is transformed to a SRU SearchRetrieveRequest
594 with same query but, possibly, different offsets.
597 Option <literal>schema</literal> specifies SRU schema
598 for retrieval. However, options <literal>elementSetName</literal> and
599 <literal>preferredRecordSyntax</literal> are ignored.
602 Options <literal>start</literal> and <literal>count</literal>
603 are supported by SRU.
604 The remaining options
605 <literal>piggyback</literal>,
606 <literal>smallSetUpperBound</literal>,
607 <literal>largeSetLowerBound</literal>,
608 <literal>mediumSetPresentNumber</literal>,
609 <literal>mediumSetElementSetName</literal>,
610 <literal>smallSetElementSetName</literal> are
614 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
615 If PQF is used, however, the PQF query is transferred anyway
616 using non-standard element <literal>pQuery</literal> in
617 SRU SearchRetrieveRequest.
620 Unfortunately, SRU does not define a database setting. Hence,
621 <literal>databaseName</literal> is unsupported and ignored.
622 However, the path part in host parameter for functions
623 <function>ZOOM_connecton_new</function> and
624 <function>ZOOM_connection_connect</function> acts as a
625 database (at least for the &yaz; SRU server).
629 <sect1 id="zoom.records"><title>Records</title>
631 A record object is a retrieval record on the client side -
632 created from result sets.
635 void ZOOM_resultset_records(ZOOM_resultset r,
637 size_t start, size_t count);
638 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
640 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
643 int ZOOM_record_error(ZOOM_record rec, const char **msg,
644 const char **addinfo, const char **diagset);
646 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
648 void ZOOM_record_destroy (ZOOM_record rec);
651 References to temporary records are returned by functions
652 <function>ZOOM_resultset_records</function> or
653 <function>ZOOM_resultset_record</function>.
656 If a persistent reference to a record is desired
657 <function>ZOOM_record_clone</function> should be used.
658 It returns a record reference that should be destroyed
659 by a call to <function>ZOOM_record_destroy</function>.
662 A single record is returned by function
663 <function>ZOOM_resultset_record</function> that takes a
664 position as argument. First record has position zero.
665 If no record could be obtained <literal>NULL</literal> is returned.
668 Error information for a record can be checked with
669 <function>ZOOM_record_error</function> which returns non-zero
670 (error code) if record is in error, called <emphasis>Surrogate
671 Diagnostics</emphasis> in Z39.50.
674 Function <function>ZOOM_resultset_records</function> retrieves
675 a number of records from a result set. Parameter <literal>start</literal>
676 and <literal>count</literal> specifies the range of records to
677 be returned. Upon completion array
678 <literal>recs[0], ..recs[count-1]</literal>
679 holds record objects for the records. The array of records
680 <literal>recs</literal> should be allocated prior the call
681 <function>ZOOM_resultset_records</function>. Note that for those
682 records that couldn't be retrieved from the target
683 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
685 <para id="zoom.record.get">
686 In order to extract information about a single record,
687 <function>ZOOM_record_get</function> is provided. The
688 function returns a pointer to certain record information. The
689 nature (type) of the pointer depends on the parameter,
690 <parameter>type</parameter>.
693 The <parameter>type</parameter> is a string of the format:
696 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
699 where <replaceable>form</replaceable> specifies the format of the
700 returned record, <replaceable>from</replaceable>
701 specifies the character set of the record in its original form
702 (as returned by the server), <replaceable>to</replaceable> specifies
703 the output (returned)
704 character set encoding.
705 If charset is not given, then no character set conversion takes place.
706 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
709 In addition, for certain types, the length
710 <literal>len</literal> passed will be set to the size in bytes of
711 the returned information.
714 The following are the supported values for <replaceable>form</replaceable>.
716 <varlistentry><term><literal>database</literal></term>
717 <listitem><para>Database of record is returned
718 as a C null-terminated string. Return type
719 <literal>const char *</literal>.
722 <varlistentry><term><literal>syntax</literal></term>
723 <listitem><para>The transfer syntax of the record is returned
724 as a C null-terminated string containing the symbolic name of
725 the record syntax, e.g. <literal>Usmarc</literal>. Return type
727 <literal>const char *</literal>.
730 <varlistentry><term><literal>render</literal></term>
731 <listitem><para>The record is returned in a display friendly
732 format. Upon completion buffer is returned
733 (type <literal>const char *</literal>) and length is stored in
734 <literal>*len</literal>.
737 <varlistentry><term><literal>raw</literal></term>
738 <listitem><para>The record is returned in the internal
739 YAZ specific format. For GRS-1, Explain, and others, the
740 raw data is returned as type
741 <literal>Z_External *</literal> which is just the type for
742 the member <literal>retrievalRecord</literal> in
743 type <literal>NamePlusRecord</literal>.
744 For SUTRS and octet aligned record (including all MARCs) the
745 octet buffer is returned and the length of the buffer.
748 <varlistentry><term><literal>xml</literal></term>
749 <listitem><para>The record is returned in XML if possible.
750 SRU and Z39.50 records with transfer syntax XML are
751 returned verbatim. MARC records are returned in
752 <ulink url="&url.marcxml;">
755 (converted from ISO2709 to MARCXML by YAZ).
756 GRS-1 and OPAC records are not supported for this form.
757 Upon completion, the XML buffer is returned
758 (type <literal>const char *</literal>) and length is stored in
759 <literal>*len</literal>.
762 <varlistentry><term><literal>opac</literal></term>
763 <listitem><para>OPAC for record is returned in XML.
770 <ulink url="&url.marc21;">MARC21</ulink>
772 <ulink url="&url.marc8;">MARC-8</ulink>
773 character set encoding.
774 An application that wishes to display in Latin-1 would use
776 render; charset=marc8,iso-8859-1
779 <sect2 id="zoom.z3950.record.behavior">
780 <title>Z39.50 Protocol behavior</title>
782 The functions <function>ZOOM_resultset_record</function> and
783 <function>ZOOM_resultset_records</function> inspects the client-side
784 record cache. Records not found in cache are fetched using
786 The functions may block (and perform network I/O) - even though option
787 <literal>async</literal> is 1, because they return records objects.
788 (and there's no way to return records objects without retrieving them!).
791 There is a trick, however, in the usage of function
792 <function>ZOOM_resultset_records</function> that allows for
793 delayed retrieval (and makes it non-blocking). By using
794 a null pointer for <parameter>recs</parameter> you're indicating
795 you're not interested in getting records objects
796 <emphasis>now</emphasis>.
799 <sect2 id="zoom.sru.record.behavior">
800 <title>SRU Protocol behavior</title>
802 The ZOOM driver for SRU treats records returned by a SRU server
803 as if they where Z39.50 records with transfer syntax XML and
804 no element set name or database name.
808 <sect1 id="zoom.scan"><title>Scan</title>
810 This section describes an interface for Scan. Scan is not an
811 official part of the ZOOM model yet. The result of a scan operation
812 is the <literal>ZOOM_scanset</literal> which is a set of terms
813 returned by a target.
817 The Scan interface is Z39.50 only. SRW version 1.0 does not
822 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
823 const char *startpqf);
825 size_t ZOOM_scanset_size(ZOOM_scanset scan);
827 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
828 int *occ, size_t *len);
830 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
831 int *occ, size_t *len);
833 void ZOOM_scanset_destroy (ZOOM_scanset scan);
835 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
838 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
842 The scan set is created by function
843 <function>ZOOM_connection_scan</function> which performs a scan
844 operation on the connection using the specified
845 <parameter>startpqf</parameter>.
846 If the operation was successful, the size of the scan set can be
847 retrieved by a call to <function>ZOOM_scanset_size</function>.
848 Like result sets, the items are numbered 0,..size-1.
849 To obtain information about a particular scan term, call function
850 <function>ZOOM_scanset_term</function>. This function takes
851 a scan set offset <literal>pos</literal> and returns a pointer
852 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
854 If present, the <literal>occ</literal> and <literal>len</literal>
855 are set to the number of occurrences and the length
856 of the actual term respectively.
857 <function>ZOOM_scanset_display_term</function> is similar to
858 <function>ZOOM_scanset_term</function> except that it returns
859 the <emphasis>display term</emphasis> rather than the raw term.
860 In a few cases, the term is different from display term. Always
861 use the display term for display and the raw term for subsequent
862 scan operations (to get more terms, next scan result, etc).
865 A scan set may be freed by a call to function
866 <function>ZOOM_scanset_destroy</function>.
867 Functions <function>ZOOM_scanset_option_get</function> and
868 <function>ZOOM_scanset_option_set</function> retrieves and sets
869 an option respectively.
873 The <parameter>startpqf</parameter> is a subset of PQF, namely
874 the Attributes+Term part. Multiple <literal>@attr</literal> can
875 be used. For example to scan in title (complete) phrases:
877 @attr 1=4 @attr 6=2 "science o"
881 <table frame="top" id="zoom.scanset.options">
882 <title>ZOOM Scan Set Options</title>
884 <colspec colwidth="4*" colname="name"></colspec>
885 <colspec colwidth="7*" colname="description"></colspec>
886 <colspec colwidth="2*" colname="default"></colspec>
889 <entry>Option</entry>
890 <entry>Description</entry>
891 <entry>Default</entry>
896 number</entry><entry>Number of Scan Terms requested in next scan.
897 After scan it holds the actual number of terms returned.
898 </entry><entry>10</entry></row>
900 position</entry><entry>Preferred Position of term in response
901 in next scan; actual position after completion of scan.
902 </entry><entry>1</entry></row>
904 stepSize</entry><entry>Step Size
905 </entry><entry>0</entry></row>
907 scanStatus</entry><entry>An integer indicating the Scan Status
909 </entry><entry>0</entry></row>
915 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
917 ZOOM offers an interface to a subset of the Z39.50 extended services
918 as well as a few privately defined ones:
923 Z39.50 Item Order (ILL).
924 See <xref linkend="zoom.item.order"/>.
929 Record Update. This allows a client to insert, modify or delete
931 See <xref linkend="zoom.record.update"/>.
936 Database Create. This a non-standard feature. Allows a client
937 to create a database.
938 See <xref linkend="zoom.database.create"/>.
943 Database Drop. This a non-standard feature. Allows a client
944 to delete/drop a database.
945 See <xref linkend="zoom.database.drop"/>.
950 Commit operation. This a non-standard feature. Allows a client
951 to commit operations.
952 See <xref linkend="zoom.commit"/>.
955 <!-- all the ILL PDU options should go here too -->
958 To create an extended service operation a <literal>ZOOM_package</literal>
959 must be created. The operation is a five step operation. The
960 package is created, package is configured by means of options,
961 the package is send, result is inspected (by means of options),
962 the package is destroyed.
965 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
966 ZOOM_options options);
968 const char *ZOOM_package_option_get(ZOOM_package p,
970 void ZOOM_package_option_set(ZOOM_package p, const char *key,
972 void ZOOM_package_send(ZOOM_package p, const char *type);
974 void ZOOM_package_destroy(ZOOM_package p);
977 The <function>ZOOM_connection_package</function> creates a
978 package for the connection given using the options specified.
981 Functions <function>ZOOM_package_option_get</function> and
982 <function>ZOOM_package_option_set</function> gets and sets
986 <function>ZOOM_package_send</function> sends
987 the package the via connection specified in
988 <function>ZOOM_connection_package</function>.
989 The <parameter>type</parameter> specifies the actual extended service
990 package type to be sent.
993 <table frame="top" id="zoom.extendedservices.options">
994 <title>Extended Service Common Options</title>
996 <colspec colwidth="4*" colname="name"></colspec>
997 <colspec colwidth="7*" colname="description"></colspec>
998 <colspec colwidth="3*" colname="default"></colspec>
1001 <entry>Option</entry>
1002 <entry>Description</entry>
1003 <entry>Default</entry>
1008 <entry>package-name</entry>
1009 <entry>Extended Service Request package name. Must be specified
1010 as part of a request</entry>
1014 <entry>user-id</entry>
1015 <entry>User ID of Extended Service Package. Is a request option</entry>
1019 <entry>function</entry>
1021 Function of package - one of <literal>create</literal>,
1022 <literal>delete</literal>, <literal>modify</literal>. Is
1025 <entry><literal>create</literal></entry>
1028 <entry>targetReference</entry>
1030 Target Reference. This is part of the response as returned
1031 by the server. Read it after a succesful operation.
1033 <entry><literal>none</literal></entry>
1039 <sect2 id="zoom.item.order"><title>Item Order</title>
1041 For Item Order, type must be set to <literal>itemorder</literal> in
1042 <function>ZOOM_package_send</function>.
1045 <table frame="top" id="zoom.item.order.options">
1046 <title>Item Order Options</title>
1048 <colspec colwidth="4*" colname="name"></colspec>
1049 <colspec colwidth="7*" colname="description"></colspec>
1050 <colspec colwidth="3*" colname="default"></colspec>
1053 <entry>Option</entry>
1054 <entry>Description</entry>
1055 <entry>Default</entry>
1060 <entry>contact-name</entry>
1061 <entry>ILL contact name</entry>
1065 <entry>contact-phone</entry>
1066 <entry>ILL contact phone</entry>
1070 <entry>contact-email</entry>
1071 <entry>ILL contact email</entry>
1075 <entry>itemorder-item</entry>
1076 <entry>Position for item (record) requested. An integer</entry>
1085 <sect2 id="zoom.record.update"><title>Record Update</title>
1087 For Record Update, type must be set to <literal>update</literal> in
1088 <function>ZOOM_package_send</function>.
1091 <table frame="top" id="zoom.record.update.options">
1092 <title>Record Update Options</title>
1094 <colspec colwidth="4*" colname="name"></colspec>
1095 <colspec colwidth="7*" colname="description"></colspec>
1096 <colspec colwidth="3*" colname="default"></colspec>
1099 <entry>Option</entry>
1100 <entry>Description</entry>
1101 <entry>Default</entry>
1106 <entry>action</entry>
1108 The update action. One of
1109 <literal>specialUpdate</literal>,
1110 <literal>recordInsert</literal>,
1111 <literal>recordReplace</literal>,
1112 <literal>recordDelete</literal>,
1113 <literal>elementUpdate</literal>.
1115 <entry><literal>specialUpdate</literal></entry>
1118 <entry>recordIdOpaque</entry>
1119 <entry>Opaque Record ID</entry>
1123 <entry>recordIdNumber</entry>
1124 <entry>Record ID number</entry>
1128 <entry>record</entry>
1129 <entry>The record itself</entry>
1133 <entry>syntax</entry>
1134 <entry>The record syntax (transfer syntax). Is a string that
1135 is a known record syntax.
1137 <entry>no syntax</entry>
1140 <entry>databaseName</entry>
1141 <entry>Database from connection object</entry>
1142 <entry>Default</entry>
1150 <sect2 id="zoom.database.create"><title>Database Create</title>
1152 For Database Create, type must be set to <literal>create</literal> in
1153 <function>ZOOM_package_send</function>.
1156 <table frame="top" id="zoom.database.create.options">
1157 <title>Database Create Options</title>
1159 <colspec colwidth="4*" colname="name"></colspec>
1160 <colspec colwidth="7*" colname="description"></colspec>
1161 <colspec colwidth="3*" colname="default"></colspec>
1164 <entry>Option</entry>
1165 <entry>Description</entry>
1166 <entry>Default</entry>
1171 <entry>databaseName</entry>
1172 <entry>Database from connection object</entry>
1173 <entry>Default</entry>
1180 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1182 For Database Drop, type must be set to <literal>drop</literal> in
1183 <function>ZOOM_package_send</function>.
1186 <table frame="top" id="zoom.database.drop.options">
1187 <title>Database Drop Options</title>
1189 <colspec colwidth="4*" colname="name"></colspec>
1190 <colspec colwidth="7*" colname="description"></colspec>
1191 <colspec colwidth="3*" colname="default"></colspec>
1194 <entry>Option</entry>
1195 <entry>Description</entry>
1196 <entry>Default</entry>
1201 <entry>databaseName</entry>
1202 <entry>Database from connection object</entry>
1203 <entry>Default</entry>
1210 <sect2 id="zoom.commit"><title>Commit Operation</title>
1212 For Commit, type must be set to <literal>commit</literal> in
1213 <function>ZOOM_package_send</function>.
1217 <sect2 id="zoom.extended.services.behavior">
1218 <title>Protocol behavior</title>
1220 All the extended services are Z39.50-only.
1224 The database create, drop and commit services are privately defined
1226 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1233 <sect1 id="zoom.options"><title>Options</title>
1235 Most &zoom; objects provide a way to specify options to change behavior.
1236 From an implementation point of view a set of options is just like
1237 an associative array / hash.
1240 ZOOM_options ZOOM_options_create (void);
1242 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1244 void ZOOM_options_destroy (ZOOM_options opt);
1247 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1249 void ZOOM_options_set (ZOOM_options opt, const char *name,
1253 typedef const char *(*ZOOM_options_callback)
1254 (void *handle, const char *name);
1256 ZOOM_options_callback
1257 ZOOM_options_set_callback (ZOOM_options opt,
1258 ZOOM_options_callback c,
1262 <sect1 id="zoom.events"><title>Events</title>
1264 If you're developing non-blocking applications, you have to deal
1268 int ZOOM_event (int no, ZOOM_connection *cs);
1271 The <function>ZOOM_event</function> executes pending events for
1272 a number of connections. Supply the number of connections in
1273 <literal>no</literal> and an array of connections in
1274 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1275 A pending event could be a sending a search, receiving a response,
1277 When an event has occurred for one of the connections, this function
1278 returns a positive integer <literal>n</literal> denoting that an event
1279 occurred for connection <literal>cs[n-1]</literal>.
1280 When no events are pending for the connections, a value of zero is
1282 To ensure that all outstanding requests are performed call this function
1283 repeatedly until zero is returned.
1286 If <function>ZOOM_event</function> returns and returns non-zero, the
1287 last event that occurred can be expected.
1290 int ZOOM_connection_last_event(ZOOM_connection cs);
1293 <function>ZOOM_connection_last_event</function> returns an event type
1294 (integer) for the last event.
1297 <table frame="top" id="zoom.event.ids">
1298 <title>ZOOM Event IDs</title>
1300 <colspec colwidth="4*" colname="name"></colspec>
1301 <colspec colwidth="7*" colname="description"></colspec>
1304 <entry>Event</entry>
1305 <entry>Description</entry>
1310 <entry>ZOOM_EVENT_NONE</entry>
1311 <entry>No event has occurred</entry>
1314 <entry>ZOOM_EVENT_CONNECT</entry>
1315 <entry>TCP/IP connect has initiated</entry>
1318 <entry>ZOOM_EVENT_SEND_DATA</entry>
1319 <entry>Data has been transmitted (sending)</entry>
1322 <entry>ZOOM_EVENT_RECV_DATA</entry>
1323 <entry>Data has been received)</entry>
1326 <entry>ZOOM_EVENT_TIMEOUT</entry>
1327 <entry>Timeout</entry>
1330 <entry>ZOOM_EVENT_UNKNOWN</entry>
1331 <entry>Unknown event</entry>
1334 <entry>ZOOM_EVENT_SEND_APDU</entry>
1335 <entry>An APDU has been transmitted (sending)</entry>
1338 <entry>ZOOM_EVENT_RECV_APDU</entry>
1339 <entry>An APDU has been received</entry>
1342 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1343 <entry>A result-set record has been received</entry>
1346 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1347 <entry>A search result been received</entry>
1355 <!-- Keep this comment at the end of the file
1360 sgml-minimize-attributes:nil
1361 sgml-always-quote-attributes:t
1364 sgml-parent-document: "yaz.xml"
1365 sgml-local-catalogs: nil
1366 sgml-namecase-general:t