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 1.55 2006-12-06 11:12:14 mike 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>
261 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
262 After a successful Init, these options may be interrogated to
263 discover whether the server claims to support the specified
265 </entry><entry>none</entry></row>
270 If either option <literal>lang</literal> or <literal>charset</literal>
272 <ulink url="&url.z39.50.charneg;">
273 Character Set and Language Negotiation</ulink> is in effect.
276 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
277 const char **addinfo);
278 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
279 const char **addinfo, const char **dset);
282 Function <function>ZOOM_connection_error</function> checks for
283 errors for the last operation(s) performed. The function returns
284 zero if no errors occurred; non-zero otherwise indicating the error.
285 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
286 holds messages for the error and additional-info if passed as
287 non-<literal>NULL</literal>. Function
288 <function>ZOOM_connection_error_x</function> is an extended version
289 of <function>ZOOM_connection_error</function> that is capable of
290 returning name of diagnostic set in <parameter>dset</parameter>.
292 <sect2 id="zoom-connection-z39.50">
293 <title>Z39.50 Protocol behavior</title>
295 The calls <function>ZOOM_connection_new</function> and
296 <function>ZOOM_connection_connect</function> establishes a TCP/IP
297 connection and sends an Initialize Request to the target if
298 possible. In addition, the calls waits for an Initialize Response
299 from the target and the result is inspected (OK or rejected).
302 If <literal>proxy</literal> is set then the client will establish
303 a TCP/IP connection with the peer as specified by the
304 <literal>proxy</literal> host and the hostname as part of the
305 connect calls will be set as part of the Initialize Request.
306 The proxy server will then "forward" the PDU's transparently
307 to the target behind the proxy.
310 For the authentication parameters, if option <literal>user</literal>
311 is set and both options <literal>group</literal> and
312 <literal>pass</literal> are unset, then Open style
313 authentication is used (Version 2/3) in which case the username
314 is usually followed by a slash, then by a password.
315 If either <literal>group</literal>
316 or <literal>pass</literal> is set then idPass authentication
317 (Version 3 only) is used. If none of the options are set, no
318 authentication parameters are set as part of the Initialize Request
322 When option <literal>async</literal> is 1, it really means that
323 all network operations are postponed (and queued) until the
324 function <literal>ZOOM_event</literal> is invoked. When doing so
325 it doesn't make sense to check for errors after
326 <literal>ZOOM_connection_new</literal> is called since that
327 operation "connecting - and init" is still incomplete and the
328 API cannot tell the outcome (yet).
331 <sect2 id="zoom.sru.init.behavior">
332 <title>SRU Protocol behavior</title>
334 The SRU protocol doesn't feature an Inititialize Request, so
335 the connection phase merely establishes a TCP/IP connection
336 with the SOAP service.
338 <para>Most of the ZOOM connection options do not
339 affect SRU and they are ignored. However, future versions
340 of &yaz; might honor <literal>implementationName</literal> and
341 put that as part of User-Agent header for HTTP requests.
344 The <literal>charset</literal> is used in the Content-Type header
349 <sect1 id="zoom.query"><title>Queries</title>
351 Query objects represents queries.
354 ZOOM_query ZOOM_query_create(void);
356 void ZOOM_query_destroy(ZOOM_query q);
358 int ZOOM_query_prefix(ZOOM_query q, const char *str);
360 int ZOOM_query_cql(ZOOM_query s, const char *str);
362 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
365 Create query objects using <function>ZOOM_query_create</function>
366 and destroy them by calling <function>ZOOM_query_destroy</function>.
367 RPN-queries can be specified in <link linkend="PQF">PQF</link>
368 notation by using the
369 function <function>ZOOM_query_prefix</function>.
370 The <function>ZOOM_query_cql</function> specifies a CQL
371 query to be sent to the server/target.
372 More query types will be added in future versions of &yaz;, such as
373 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
374 etc. In addition to a search, a sort criteria may be set. Function
375 <function>ZOOM_query_sortby</function> specifies a
376 sort criteria using the same string notation for sort as offered by
377 the <link linkend="sortspec">YAZ client</link>.
379 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
381 The query object is just an interface for the member Query
382 in the SearchRequest. The sortby-function is an interface to the
383 sortSequence member of the SortRequest.
387 <sect1 id="zoom.resultsets"><title>Result sets</title>
389 The result set object is a container for records returned from
393 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
396 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
399 void ZOOM_resultset_destroy(ZOOM_resultset r);
402 Function <function>ZOOM_connection_search</function> creates
403 a result set given a connection and query.
404 Destroy a result set by calling
405 <function>ZOOM_resultset_destroy</function>.
406 Simple clients may using PQF only may use function
407 <function>ZOOM_connection_search_pqf</function> in which case
408 creating query objects is not necessary.
411 void ZOOM_resultset_option_set (ZOOM_resultset r,
415 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
418 size_t ZOOM_resultset_size (ZOOM_resultset r);
421 Functions <function>ZOOM_resultset_options_set</function> and
422 <function>ZOOM_resultset_get</function> sets and gets an option
423 for a result set similar to <function>ZOOM_connection_option_get</function>
424 and <function>ZOOM_connection_option_set</function>.
427 The number of hits also called result-count is returned by
428 function <function>ZOOM_resultset_size</function>.
430 <table id="zoom.resultset.options"
431 frame="top"><title>ZOOM Result set Options</title>
433 <colspec colwidth="4*" colname="name"></colspec>
434 <colspec colwidth="7*" colname="description"></colspec>
435 <colspec colwidth="2*" colname="default"></colspec>
438 <entry>Option</entry>
439 <entry>Description</entry>
440 <entry>Default</entry>
445 start</entry><entry>Offset of first record to be
446 retrieved from target. First record has offset 0 unlike the
447 protocol specifications where first record has position 1.
448 </entry><entry>0</entry></row>
450 count</entry><entry>Number of records to be retrieved.
451 </entry><entry>0</entry></row>
453 presentChunk</entry><entry>The number of records to be
454 requested from the server in each chunk (present requst). The
455 value 0 means to request all the records in a single chunk.
456 (The old <literal>step</literal>
457 option is also supported for the benefit of old applications.)
458 </entry><entry>0</entry></row>
460 elementSetName</entry><entry>Element-Set name of records.
461 Most targets should honor element set name <literal>B</literal>
462 and <literal>F</literal> for brief and full respectively.
463 </entry><entry>none</entry></row>
465 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
466 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
467 </entry><entry>none</entry></row>
469 schema</entry><entry>Schema for retrieval, such as
470 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
471 </entry><entry>none</entry></row>
473 setname</entry><entry>Name of Result Set (Result Set ID).
474 If this option isn't set, the ZOOM module will automatically
475 allocate a result set name.
476 </entry><entry>default</entry></row>
481 For servers that support Search Info report, the following
482 options may be read using <function>ZOOM_resultset_get</function>.
483 This detailed information is read after a successful search has
487 This information is a list of of items, where each item is
488 information about a term or subquery. All items in the list
490 <literal>SearchResult.</literal><replaceable>no</replaceable>
491 where no presents the item number (0=first, 1=second).
492 Read <literal>searchresult.size</literal> to determine the
495 <table id="zoom.search.info.report.options"
496 frame="top"><title>Search Info Report Options</title>
498 <colspec colwidth="4*" colname="name"></colspec>
499 <colspec colwidth="7*" colname="description"></colspec>
502 <entry>Option</entry>
503 <entry>Description</entry>
508 <entry>searchresult.size</entry>
510 number of search result entries. This option is-nonexistant
511 if no entries are returned by the server.
515 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
516 <entry>sub query ID</entry>
519 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
520 <entry>result count for item (number of hits)</entry>
523 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
524 <entry>subquery term</entry>
528 searchresult.<replaceable>no</replaceable>.interpretation.term
530 <entry>interpretation term</entry>
534 searchresult.<replaceable>no</replaceable>.recommendation.term
536 <entry>recommendation term</entry>
541 <sect2 id="zoom.z3950.resultset.behavior">
542 <title>Z39.50 Protocol behavior</title>
544 The creation of a result set involves at least a SearchRequest
545 - SearchResponse protocol handshake. Following that, if a sort
546 criteria was specified as part of the query, a SortRequest -
547 SortResponse handshake takes place. Note that it is necessary to
548 perform sorting before any retrieval takes place, so no records will
549 be returned from the target as part of the SearchResponse because these
550 would be unsorted. Hence, piggyback is disabled when sort criteria
551 are set. Following Search - and a possible sort - Retrieval takes
552 place - as one or more Present Requests/Response pairs being
556 The API allows for two different modes for retrieval. A high level
557 mode which is somewhat more powerful and a low level one.
558 The low level is enabled when searching on a Connection object
559 for which the settings
560 <literal>smallSetUpperBound</literal>,
561 <literal>mediumSetPresentNumber</literal> and
562 <literal>largeSetLowerBound</literal> are set. The low level mode
563 thus allows you to precisely set how records are returned as part
564 of a search response as offered by the Z39.50 protocol.
565 Since the client may be retrieving records as part of the
566 search response, this mode doesn't work well if sorting is used.
569 The high-level mode allows you to fetch a range of records from
570 the result set with a given start offset. When you use this mode
571 the client will automatically use piggyback if that is possible
572 with the target and perform one or more present requests as needed.
573 Even if the target returns fewer records as part of a present response
574 because of a record size limit, etc. the client will repeat sending
575 present requests. As an example, if option <literal>start</literal>
576 is 0 (default) and <literal>count</literal> is 4, and
577 <literal>piggyback</literal> is 1 (default) and no sorting criteria
578 is specified, then the client will attempt to retrieve the 4
579 records as part the search response (using piggyback). On the other
580 hand, if either <literal>start</literal> is positive or if
581 a sorting criteria is set, or if <literal>piggyback</literal>
582 is 0, then the client will not perform piggyback but send Present
586 If either of the options <literal>mediumSetElementSetName</literal> and
587 <literal>smallSetElementSetName</literal> are unset, the value
588 of option <literal>elementSetName</literal> is used for piggyback
589 searches. This means that for the high-level mode you only have
590 to specify one elementSetName option rather than three.
593 <sect2 id="zoom.sru.resultset.behavior">
594 <title>SRU Protocol behavior</title>
596 Current version of &yaz; does not take advantage of a result set id
597 returned by the SRU server. Future versions might do, however.
598 Since, the ZOOM driver does not save result set IDs any
599 present (retrieval) is transformed to a SRU SearchRetrieveRequest
600 with same query but, possibly, different offsets.
603 Option <literal>schema</literal> specifies SRU schema
604 for retrieval. However, options <literal>elementSetName</literal> and
605 <literal>preferredRecordSyntax</literal> are ignored.
608 Options <literal>start</literal> and <literal>count</literal>
609 are supported by SRU.
610 The remaining options
611 <literal>piggyback</literal>,
612 <literal>smallSetUpperBound</literal>,
613 <literal>largeSetLowerBound</literal>,
614 <literal>mediumSetPresentNumber</literal>,
615 <literal>mediumSetElementSetName</literal>,
616 <literal>smallSetElementSetName</literal> are
620 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
621 If PQF is used, however, the PQF query is transferred anyway
622 using non-standard element <literal>pQuery</literal> in
623 SRU SearchRetrieveRequest.
626 Unfortunately, SRU does not define a database setting. Hence,
627 <literal>databaseName</literal> is unsupported and ignored.
628 However, the path part in host parameter for functions
629 <function>ZOOM_connecton_new</function> and
630 <function>ZOOM_connection_connect</function> acts as a
631 database (at least for the &yaz; SRU server).
635 <sect1 id="zoom.records"><title>Records</title>
637 A record object is a retrieval record on the client side -
638 created from result sets.
641 void ZOOM_resultset_records(ZOOM_resultset r,
643 size_t start, size_t count);
644 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
646 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
649 int ZOOM_record_error(ZOOM_record rec, const char **msg,
650 const char **addinfo, const char **diagset);
652 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
654 void ZOOM_record_destroy (ZOOM_record rec);
657 References to temporary records are returned by functions
658 <function>ZOOM_resultset_records</function> or
659 <function>ZOOM_resultset_record</function>.
662 If a persistent reference to a record is desired
663 <function>ZOOM_record_clone</function> should be used.
664 It returns a record reference that should be destroyed
665 by a call to <function>ZOOM_record_destroy</function>.
668 A single record is returned by function
669 <function>ZOOM_resultset_record</function> that takes a
670 position as argument. First record has position zero.
671 If no record could be obtained <literal>NULL</literal> is returned.
674 Error information for a record can be checked with
675 <function>ZOOM_record_error</function> which returns non-zero
676 (error code) if record is in error, called <emphasis>Surrogate
677 Diagnostics</emphasis> in Z39.50.
680 Function <function>ZOOM_resultset_records</function> retrieves
681 a number of records from a result set. Parameter <literal>start</literal>
682 and <literal>count</literal> specifies the range of records to
683 be returned. Upon completion array
684 <literal>recs[0], ..recs[count-1]</literal>
685 holds record objects for the records. The array of records
686 <literal>recs</literal> should be allocated prior the call
687 <function>ZOOM_resultset_records</function>. Note that for those
688 records that couldn't be retrieved from the target
689 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
691 <para id="zoom.record.get">
692 In order to extract information about a single record,
693 <function>ZOOM_record_get</function> is provided. The
694 function returns a pointer to certain record information. The
695 nature (type) of the pointer depends on the parameter,
696 <parameter>type</parameter>.
699 The <parameter>type</parameter> is a string of the format:
702 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
705 where <replaceable>form</replaceable> specifies the format of the
706 returned record, <replaceable>from</replaceable>
707 specifies the character set of the record in its original form
708 (as returned by the server), <replaceable>to</replaceable> specifies
709 the output (returned)
710 character set encoding.
711 If charset is not given, then no character set conversion takes place.
712 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
715 In addition, for certain types, the length
716 <literal>len</literal> passed will be set to the size in bytes of
717 the returned information.
720 The following are the supported values for <replaceable>form</replaceable>.
722 <varlistentry><term><literal>database</literal></term>
723 <listitem><para>Database of record is returned
724 as a C null-terminated string. Return type
725 <literal>const char *</literal>.
728 <varlistentry><term><literal>syntax</literal></term>
729 <listitem><para>The transfer syntax of the record is returned
730 as a C null-terminated string containing the symbolic name of
731 the record syntax, e.g. <literal>Usmarc</literal>. Return type
733 <literal>const char *</literal>.
736 <varlistentry><term><literal>render</literal></term>
737 <listitem><para>The record is returned in a display friendly
738 format. Upon completion buffer is returned
739 (type <literal>const char *</literal>) and length is stored in
740 <literal>*len</literal>.
743 <varlistentry><term><literal>raw</literal></term>
744 <listitem><para>The record is returned in the internal
745 YAZ specific format. For GRS-1, Explain, and others, the
746 raw data is returned as type
747 <literal>Z_External *</literal> which is just the type for
748 the member <literal>retrievalRecord</literal> in
749 type <literal>NamePlusRecord</literal>.
750 For SUTRS and octet aligned record (including all MARCs) the
751 octet buffer is returned and the length of the buffer.
754 <varlistentry><term><literal>xml</literal></term>
755 <listitem><para>The record is returned in XML if possible.
756 SRU and Z39.50 records with transfer syntax XML are
757 returned verbatim. MARC records are returned in
758 <ulink url="&url.marcxml;">
761 (converted from ISO2709 to MARCXML by YAZ).
762 GRS-1 and OPAC records are not supported for this form.
763 Upon completion, the XML buffer is returned
764 (type <literal>const char *</literal>) and length is stored in
765 <literal>*len</literal>.
768 <varlistentry><term><literal>opac</literal></term>
769 <listitem><para>OPAC for record is returned in XML.
776 <ulink url="&url.marc21;">MARC21</ulink>
778 <ulink url="&url.marc8;">MARC-8</ulink>
779 character set encoding.
780 An application that wishes to display in Latin-1 would use
782 render; charset=marc8,iso-8859-1
785 <sect2 id="zoom.z3950.record.behavior">
786 <title>Z39.50 Protocol behavior</title>
788 The functions <function>ZOOM_resultset_record</function> and
789 <function>ZOOM_resultset_records</function> inspects the client-side
790 record cache. Records not found in cache are fetched using
792 The functions may block (and perform network I/O) - even though option
793 <literal>async</literal> is 1, because they return records objects.
794 (and there's no way to return records objects without retrieving them!).
797 There is a trick, however, in the usage of function
798 <function>ZOOM_resultset_records</function> that allows for
799 delayed retrieval (and makes it non-blocking). By using
800 a null pointer for <parameter>recs</parameter> you're indicating
801 you're not interested in getting records objects
802 <emphasis>now</emphasis>.
805 <sect2 id="zoom.sru.record.behavior">
806 <title>SRU Protocol behavior</title>
808 The ZOOM driver for SRU treats records returned by a SRU server
809 as if they where Z39.50 records with transfer syntax XML and
810 no element set name or database name.
814 <sect1 id="zoom.scan"><title>Scan</title>
816 This section describes an interface for Scan. Scan is not an
817 official part of the ZOOM model yet. The result of a scan operation
818 is the <literal>ZOOM_scanset</literal> which is a set of terms
819 returned by a target.
823 The Scan interface is Z39.50 only. SRW version 1.0 does not
828 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
829 const char *startpqf);
831 size_t ZOOM_scanset_size(ZOOM_scanset scan);
833 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
834 int *occ, size_t *len);
836 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
837 int *occ, size_t *len);
839 void ZOOM_scanset_destroy (ZOOM_scanset scan);
841 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
844 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
848 The scan set is created by function
849 <function>ZOOM_connection_scan</function> which performs a scan
850 operation on the connection using the specified
851 <parameter>startpqf</parameter>.
852 If the operation was successful, the size of the scan set can be
853 retrieved by a call to <function>ZOOM_scanset_size</function>.
854 Like result sets, the items are numbered 0,..size-1.
855 To obtain information about a particular scan term, call function
856 <function>ZOOM_scanset_term</function>. This function takes
857 a scan set offset <literal>pos</literal> and returns a pointer
858 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
860 If present, the <literal>occ</literal> and <literal>len</literal>
861 are set to the number of occurrences and the length
862 of the actual term respectively.
863 <function>ZOOM_scanset_display_term</function> is similar to
864 <function>ZOOM_scanset_term</function> except that it returns
865 the <emphasis>display term</emphasis> rather than the raw term.
866 In a few cases, the term is different from display term. Always
867 use the display term for display and the raw term for subsequent
868 scan operations (to get more terms, next scan result, etc).
871 A scan set may be freed by a call to function
872 <function>ZOOM_scanset_destroy</function>.
873 Functions <function>ZOOM_scanset_option_get</function> and
874 <function>ZOOM_scanset_option_set</function> retrieves and sets
875 an option respectively.
879 The <parameter>startpqf</parameter> is a subset of PQF, namely
880 the Attributes+Term part. Multiple <literal>@attr</literal> can
881 be used. For example to scan in title (complete) phrases:
883 @attr 1=4 @attr 6=2 "science o"
887 <table frame="top" id="zoom.scanset.options">
888 <title>ZOOM Scan Set Options</title>
890 <colspec colwidth="4*" colname="name"></colspec>
891 <colspec colwidth="7*" colname="description"></colspec>
892 <colspec colwidth="2*" colname="default"></colspec>
895 <entry>Option</entry>
896 <entry>Description</entry>
897 <entry>Default</entry>
902 number</entry><entry>Number of Scan Terms requested in next scan.
903 After scan it holds the actual number of terms returned.
904 </entry><entry>10</entry></row>
906 position</entry><entry>Preferred Position of term in response
907 in next scan; actual position after completion of scan.
908 </entry><entry>1</entry></row>
910 stepSize</entry><entry>Step Size
911 </entry><entry>0</entry></row>
913 scanStatus</entry><entry>An integer indicating the Scan Status
915 </entry><entry>0</entry></row>
921 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
923 ZOOM offers an interface to a subset of the Z39.50 extended services
924 as well as a few privately defined ones:
929 Z39.50 Item Order (ILL).
930 See <xref linkend="zoom.item.order"/>.
935 Record Update. This allows a client to insert, modify or delete
937 See <xref linkend="zoom.record.update"/>.
942 Database Create. This a non-standard feature. Allows a client
943 to create a database.
944 See <xref linkend="zoom.database.create"/>.
949 Database Drop. This a non-standard feature. Allows a client
950 to delete/drop a database.
951 See <xref linkend="zoom.database.drop"/>.
956 Commit operation. This a non-standard feature. Allows a client
957 to commit operations.
958 See <xref linkend="zoom.commit"/>.
961 <!-- all the ILL PDU options should go here too -->
964 To create an extended service operation a <literal>ZOOM_package</literal>
965 must be created. The operation is a five step operation. The
966 package is created, package is configured by means of options,
967 the package is send, result is inspected (by means of options),
968 the package is destroyed.
971 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
972 ZOOM_options options);
974 const char *ZOOM_package_option_get(ZOOM_package p,
976 void ZOOM_package_option_set(ZOOM_package p, const char *key,
978 void ZOOM_package_send(ZOOM_package p, const char *type);
980 void ZOOM_package_destroy(ZOOM_package p);
983 The <function>ZOOM_connection_package</function> creates a
984 package for the connection given using the options specified.
987 Functions <function>ZOOM_package_option_get</function> and
988 <function>ZOOM_package_option_set</function> gets and sets
992 <function>ZOOM_package_send</function> sends
993 the package the via connection specified in
994 <function>ZOOM_connection_package</function>.
995 The <parameter>type</parameter> specifies the actual extended service
996 package type to be sent.
999 <table frame="top" id="zoom.extendedservices.options">
1000 <title>Extended Service Common Options</title>
1002 <colspec colwidth="4*" colname="name"></colspec>
1003 <colspec colwidth="7*" colname="description"></colspec>
1004 <colspec colwidth="3*" colname="default"></colspec>
1007 <entry>Option</entry>
1008 <entry>Description</entry>
1009 <entry>Default</entry>
1014 <entry>package-name</entry>
1015 <entry>Extended Service Request package name. Must be specified
1016 as part of a request</entry>
1020 <entry>user-id</entry>
1021 <entry>User ID of Extended Service Package. Is a request option</entry>
1025 <entry>function</entry>
1027 Function of package - one of <literal>create</literal>,
1028 <literal>delete</literal>, <literal>modify</literal>. Is
1031 <entry><literal>create</literal></entry>
1034 <entry>targetReference</entry>
1036 Target Reference. This is part of the response as returned
1037 by the server. Read it after a succesful operation.
1039 <entry><literal>none</literal></entry>
1045 <sect2 id="zoom.item.order"><title>Item Order</title>
1047 For Item Order, type must be set to <literal>itemorder</literal> in
1048 <function>ZOOM_package_send</function>.
1051 <table frame="top" id="zoom.item.order.options">
1052 <title>Item Order Options</title>
1054 <colspec colwidth="4*" colname="name"></colspec>
1055 <colspec colwidth="7*" colname="description"></colspec>
1056 <colspec colwidth="3*" colname="default"></colspec>
1059 <entry>Option</entry>
1060 <entry>Description</entry>
1061 <entry>Default</entry>
1066 <entry>contact-name</entry>
1067 <entry>ILL contact name</entry>
1071 <entry>contact-phone</entry>
1072 <entry>ILL contact phone</entry>
1076 <entry>contact-email</entry>
1077 <entry>ILL contact email</entry>
1081 <entry>itemorder-item</entry>
1082 <entry>Position for item (record) requested. An integer</entry>
1091 <sect2 id="zoom.record.update"><title>Record Update</title>
1093 For Record Update, type must be set to <literal>update</literal> in
1094 <function>ZOOM_package_send</function>.
1097 <table frame="top" id="zoom.record.update.options">
1098 <title>Record Update Options</title>
1100 <colspec colwidth="4*" colname="name"></colspec>
1101 <colspec colwidth="7*" colname="description"></colspec>
1102 <colspec colwidth="3*" colname="default"></colspec>
1105 <entry>Option</entry>
1106 <entry>Description</entry>
1107 <entry>Default</entry>
1112 <entry>action</entry>
1114 The update action. One of
1115 <literal>specialUpdate</literal>,
1116 <literal>recordInsert</literal>,
1117 <literal>recordReplace</literal>,
1118 <literal>recordDelete</literal>,
1119 <literal>elementUpdate</literal>.
1121 <entry><literal>specialUpdate</literal></entry>
1124 <entry>recordIdOpaque</entry>
1125 <entry>Opaque Record ID</entry>
1129 <entry>recordIdNumber</entry>
1130 <entry>Record ID number</entry>
1134 <entry>record</entry>
1135 <entry>The record itself</entry>
1139 <entry>syntax</entry>
1140 <entry>The record syntax (transfer syntax). Is a string that
1141 is a known record syntax.
1143 <entry>no syntax</entry>
1146 <entry>databaseName</entry>
1147 <entry>Database from connection object</entry>
1148 <entry>Default</entry>
1156 <sect2 id="zoom.database.create"><title>Database Create</title>
1158 For Database Create, type must be set to <literal>create</literal> in
1159 <function>ZOOM_package_send</function>.
1162 <table frame="top" id="zoom.database.create.options">
1163 <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.database.drop"><title>Database Drop</title>
1188 For Database Drop, type must be set to <literal>drop</literal> in
1189 <function>ZOOM_package_send</function>.
1192 <table frame="top" id="zoom.database.drop.options">
1193 <title>Database Drop Options</title>
1195 <colspec colwidth="4*" colname="name"></colspec>
1196 <colspec colwidth="7*" colname="description"></colspec>
1197 <colspec colwidth="3*" colname="default"></colspec>
1200 <entry>Option</entry>
1201 <entry>Description</entry>
1202 <entry>Default</entry>
1207 <entry>databaseName</entry>
1208 <entry>Database from connection object</entry>
1209 <entry>Default</entry>
1216 <sect2 id="zoom.commit"><title>Commit Operation</title>
1218 For Commit, type must be set to <literal>commit</literal> in
1219 <function>ZOOM_package_send</function>.
1223 <sect2 id="zoom.extended.services.behavior">
1224 <title>Protocol behavior</title>
1226 All the extended services are Z39.50-only.
1230 The database create, drop and commit services are privately defined
1232 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1239 <sect1 id="zoom.options"><title>Options</title>
1241 Most &zoom; objects provide a way to specify options to change behavior.
1242 From an implementation point of view a set of options is just like
1243 an associative array / hash.
1246 ZOOM_options ZOOM_options_create (void);
1248 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1250 void ZOOM_options_destroy (ZOOM_options opt);
1253 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1255 void ZOOM_options_set (ZOOM_options opt, const char *name,
1259 typedef const char *(*ZOOM_options_callback)
1260 (void *handle, const char *name);
1262 ZOOM_options_callback
1263 ZOOM_options_set_callback (ZOOM_options opt,
1264 ZOOM_options_callback c,
1268 <sect1 id="zoom.events"><title>Events</title>
1270 If you're developing non-blocking applications, you have to deal
1274 int ZOOM_event (int no, ZOOM_connection *cs);
1277 The <function>ZOOM_event</function> executes pending events for
1278 a number of connections. Supply the number of connections in
1279 <literal>no</literal> and an array of connections in
1280 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1281 A pending event could be a sending a search, receiving a response,
1283 When an event has occurred for one of the connections, this function
1284 returns a positive integer <literal>n</literal> denoting that an event
1285 occurred for connection <literal>cs[n-1]</literal>.
1286 When no events are pending for the connections, a value of zero is
1288 To ensure that all outstanding requests are performed call this function
1289 repeatedly until zero is returned.
1292 If <function>ZOOM_event</function> returns and returns non-zero, the
1293 last event that occurred can be expected.
1296 int ZOOM_connection_last_event(ZOOM_connection cs);
1299 <function>ZOOM_connection_last_event</function> returns an event type
1300 (integer) for the last event.
1303 <table frame="top" id="zoom.event.ids">
1304 <title>ZOOM Event IDs</title>
1306 <colspec colwidth="4*" colname="name"></colspec>
1307 <colspec colwidth="7*" colname="description"></colspec>
1310 <entry>Event</entry>
1311 <entry>Description</entry>
1316 <entry>ZOOM_EVENT_NONE</entry>
1317 <entry>No event has occurred</entry>
1320 <entry>ZOOM_EVENT_CONNECT</entry>
1321 <entry>TCP/IP connect has initiated</entry>
1324 <entry>ZOOM_EVENT_SEND_DATA</entry>
1325 <entry>Data has been transmitted (sending)</entry>
1328 <entry>ZOOM_EVENT_RECV_DATA</entry>
1329 <entry>Data has been received)</entry>
1332 <entry>ZOOM_EVENT_TIMEOUT</entry>
1333 <entry>Timeout</entry>
1336 <entry>ZOOM_EVENT_UNKNOWN</entry>
1337 <entry>Unknown event</entry>
1340 <entry>ZOOM_EVENT_SEND_APDU</entry>
1341 <entry>An APDU has been transmitted (sending)</entry>
1344 <entry>ZOOM_EVENT_RECV_APDU</entry>
1345 <entry>An APDU has been received</entry>
1348 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1349 <entry>A result-set record has been received</entry>
1352 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1353 <entry>A search result been received</entry>
1361 <!-- Keep this comment at the end of the file
1366 sgml-minimize-attributes:nil
1367 sgml-always-quote-attributes:t
1370 sgml-parent-document: "yaz.xml"
1371 sgml-local-catalogs: nil
1372 sgml-namecase-general:t