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 1.61 2007-06-29 08:05:07 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>). Using the facility for embedding
42 options in target strings, a connection can be forced to use SRU
43 rather the SRW (the default) by prefixing the target string with
44 <literal>sru=get,</literal>, like this:
45 <literal>sru=get,http://sru.miketaylor.org.uk:80/sru.pl</literal>
50 The lack of a simple Z39.50 client API for &yaz; has become more
51 and more apparent over time. So when the first &zoom; specification
53 an implementation for &yaz; was quickly developed. For the first time, it is
54 now as easy (or easier!) to develop clients than servers with &yaz;. This
55 chapter describes the &zoom; C binding. Before going further, please
56 reconsider whether C is the right programming language for the job.
57 There are other language bindings available for &yaz;, and still
59 are in active development. See the
60 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
65 In order to fully understand this chapter you should read and
66 try the example programs <literal>zoomtst1.c</literal>,
67 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
72 The C language misses features found in object oriented languages
73 such as C++, Java, etc. For example, you'll have to manually,
74 destroy all objects you create, even though you may think of them as
75 temporary. Most objects has a <literal>_create</literal> - and a
76 <literal>_destroy</literal> variant.
77 All objects are in fact pointers to internal stuff, but you don't see
78 that because of typedefs. All destroy methods should gracefully ignore a
79 <literal>NULL</literal> pointer.
82 In each of the sections below you'll find a sub section called
83 protocol behavior, that describes how the API maps to the Z39.50
86 <sect1 id="zoom-connections"><title>Connections</title>
88 <para>The Connection object is a session with a target.
91 #include <yaz/zoom.h>
93 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
95 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
97 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
99 void ZOOM_connection_destroy (ZOOM_connection c);
102 Connection objects are created with either function
103 <function>ZOOM_connection_new</function> or
104 <function>ZOOM_connection_create</function>.
105 The former creates and automatically attempts to establish a network
106 connection with the target. The latter doesn't establish
107 a connection immediately, thus allowing you to specify options
108 before establishing network connection using the function
109 <function>ZOOM_connection_connect</function>.
110 If the port number, <literal>portnum</literal>, is zero, the
111 <literal>host</literal> is consulted for a port specification.
112 If no port is given, 210 is used. A colon denotes the beginning of
113 a port number in the host string. If the host string includes a
114 slash, the following part specifies a database for the connection.
117 You can prefix the host with a scheme followed by colon. The
118 default scheme is <literal>tcp</literal> (Z39.50 protocol).
119 The scheme <literal>http</literal> selects SRU over HTTP.
122 You can prefix the scheme-qualified host-string with one or more
124 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
125 sequences, each of which represents an option to be set into the
126 connection structure <emphasis>before</emphasis> the
127 protocol-level connection is forged and the initialization
128 handshake takes place. This facility can be used to provide
129 authentication credentials, as in host-strings such as:
130 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
133 Connection objects should be destroyed using the function
134 <function>ZOOM_connection_destroy</function>.
137 void ZOOM_connection_option_set(ZOOM_connection c,
138 const char *key, const char *val);
140 void ZOOM_connection_option_setl(ZOOM_connection c,
142 const char *val, int len);
144 const char *ZOOM_connection_option_get(ZOOM_connection c,
146 const char *ZOOM_connection_option_getl(ZOOM_connection c,
151 The functions <function>ZOOM_connection_option_set</function> and
152 <function>ZOOM_connection_option_setl</function> allows you to
153 set an option given by <parameter>key</parameter> to the value
154 <parameter>value</parameter> for the connection.
155 For <function>ZOOM_connection_option_set</function>, the
156 value is assumed to be a 0-terminated string. Function
157 <function>ZOOM_connection_option_setl</function> specifies a
158 value of a certain size (len).
161 Functions <function>ZOOM_connection_option_get</function> and
162 <function>ZOOM_connection_option_getl</function> returns
163 the value for an option given by <parameter>key</parameter>.
165 <table id="zoom-connection-options" frame="top">
166 <title>ZOOM Connection Options</title>
168 <colspec colwidth="4*" colname="name"></colspec>
169 <colspec colwidth="7*" colname="description"></colspec>
170 <colspec colwidth="3*" colname="default"></colspec>
173 <entry>Option</entry>
174 <entry>Description</entry>
175 <entry>Default</entry>
180 implementationName</entry><entry>Name of Your client
181 </entry><entry>none</entry></row>
183 user</entry><entry>Authentication user name
184 </entry><entry>none</entry></row>
186 group</entry><entry>Authentication group name
187 </entry><entry>none</entry></row>
189 password</entry><entry>Authentication password.
190 </entry><entry>none</entry></row>
192 host</entry><entry>Target host. This setting is "read-only".
193 It's automatically set internally when connecting to a target.
194 </entry><entry>none</entry></row>
196 proxy</entry><entry>Proxy host
197 </entry><entry>none</entry></row>
199 async</entry><entry>If true (1) the connection operates in
200 asynchronous operation which means that all calls are non-blocking
202 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
203 </entry><entry>0</entry></row>
205 maximumRecordSize</entry><entry> Maximum size of single record.
206 </entry><entry>1 MB</entry></row>
208 preferredMessageSize</entry><entry> Maximum size of multiple records.
209 </entry><entry>1 MB</entry></row>
211 lang</entry><entry> Language for negotiation.
212 </entry><entry>none</entry></row>
214 charset</entry><entry> Character set for negotiation.
215 </entry><entry>none</entry></row>
217 serverImplementationId</entry><entry>
218 Implementation ID of server. (The old targetImplementationId
219 option is also supported for the benefit of old applications.)
220 </entry><entry>none</entry></row>
222 targetImplementationName</entry><entry>
223 Implementation Name of server. (The old
224 targetImplementationName option is also supported for the
225 benefit of old applications.)
226 </entry><entry>none</entry></row>
228 serverImplementationVersion</entry><entry>
229 Implementation Version of server. (the old
230 targetImplementationVersion option is also supported for the
231 benefit of old applications.)
232 </entry><entry>none</entry></row>
234 databaseName</entry><entry>One or more database names
235 separated by character plus (<literal>+</literal>), which to
236 be used by subsequent search requests on this Connection.
237 </entry><entry>Default</entry></row>
239 piggyback</entry><entry>True (1) if piggyback should be
240 used in searches; false (0) if not.
241 </entry><entry>1</entry></row>
243 smallSetUpperBound</entry><entry>If hits is less than or equal to this
244 value, then target will return all records using small element set name
245 </entry><entry>0</entry></row>
247 largeSetLowerBound</entry><entry>If hits is greater than this
248 value, the target will return no records.
249 </entry><entry>1</entry></row>
251 mediumSetPresentNumber</entry><entry>This value represents
252 the number of records to be returned as part of a search when when
253 hits is less than or equal to large set lower bound and if hits
254 is greater than small set upper bound.
255 </entry><entry>0</entry></row>
257 smallSetElementSetName</entry><entry>
258 The element set name to be used for small result sets.
259 </entry><entry>none</entry></row>
261 mediumSetElementSetName</entry><entry>
262 The element set name to be for medium-sized result sets.
263 </entry><entry>none</entry></row>
265 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
266 After a successful Init, these options may be interrogated to
267 discover whether the server claims to support the specified
269 </entry><entry>none</entry></row>
274 If either option <literal>lang</literal> or <literal>charset</literal>
276 <ulink url="&url.z39.50.charneg;">
277 Character Set and Language Negotiation</ulink> is in effect.
280 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
281 const char **addinfo);
282 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
283 const char **addinfo, const char **dset);
286 Function <function>ZOOM_connection_error</function> checks for
287 errors for the last operation(s) performed. The function returns
288 zero if no errors occurred; non-zero otherwise indicating the error.
289 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
290 holds messages for the error and additional-info if passed as
291 non-<literal>NULL</literal>. Function
292 <function>ZOOM_connection_error_x</function> is an extended version
293 of <function>ZOOM_connection_error</function> that is capable of
294 returning name of diagnostic set in <parameter>dset</parameter>.
296 <sect2 id="zoom-connection-z39.50">
297 <title>Z39.50 Protocol behavior</title>
299 The calls <function>ZOOM_connection_new</function> and
300 <function>ZOOM_connection_connect</function> establishes a TCP/IP
301 connection and sends an Initialize Request to the target if
302 possible. In addition, the calls waits for an Initialize Response
303 from the target and the result is inspected (OK or rejected).
306 If <literal>proxy</literal> is set then the client will establish
307 a TCP/IP connection with the peer as specified by the
308 <literal>proxy</literal> host and the hostname as part of the
309 connect calls will be set as part of the Initialize Request.
310 The proxy server will then "forward" the PDU's transparently
311 to the target behind the proxy.
314 For the authentication parameters, if option <literal>user</literal>
315 is set and both options <literal>group</literal> and
316 <literal>pass</literal> are unset, then Open style
317 authentication is used (Version 2/3) in which case the username
318 is usually followed by a slash, then by a password.
319 If either <literal>group</literal>
320 or <literal>pass</literal> is set then idPass authentication
321 (Version 3 only) is used. If none of the options are set, no
322 authentication parameters are set as part of the Initialize Request
326 When option <literal>async</literal> is 1, it really means that
327 all network operations are postponed (and queued) until the
328 function <literal>ZOOM_event</literal> is invoked. When doing so
329 it doesn't make sense to check for errors after
330 <literal>ZOOM_connection_new</literal> is called since that
331 operation "connecting - and init" is still incomplete and the
332 API cannot tell the outcome (yet).
335 <sect2 id="zoom.sru.init.behavior">
336 <title>SRU Protocol behavior</title>
338 The SRU protocol doesn't feature an Inititialize Request, so
339 the connection phase merely establishes a TCP/IP connection
340 with the SOAP service.
342 <para>Most of the ZOOM connection options do not
343 affect SRU and they are ignored. However, future versions
344 of &yaz; might honor <literal>implementationName</literal> and
345 put that as part of User-Agent header for HTTP requests.
348 The <literal>charset</literal> is used in the Content-Type header
353 <sect1 id="zoom.query"><title>Queries</title>
355 Query objects represents queries.
358 ZOOM_query ZOOM_query_create(void);
360 void ZOOM_query_destroy(ZOOM_query q);
362 int ZOOM_query_prefix(ZOOM_query q, const char *str);
364 int ZOOM_query_cql(ZOOM_query s, const char *str);
366 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
369 Create query objects using <function>ZOOM_query_create</function>
370 and destroy them by calling <function>ZOOM_query_destroy</function>.
371 RPN-queries can be specified in <link linkend="PQF">PQF</link>
372 notation by using the
373 function <function>ZOOM_query_prefix</function>.
374 The <function>ZOOM_query_cql</function> specifies a CQL
375 query to be sent to the server/target.
376 More query types will be added in future versions of &yaz;, such as
377 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
378 etc. In addition to a search, a sort criteria may be set. Function
379 <function>ZOOM_query_sortby</function> specifies a
380 sort criteria using the same string notation for sort as offered by
381 the <link linkend="sortspec">YAZ client</link>.
383 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
385 The query object is just an interface for the member Query
386 in the SearchRequest. The sortby-function is an interface to the
387 sortSequence member of the SortRequest.
391 <sect1 id="zoom.resultsets"><title>Result sets</title>
393 The result set object is a container for records returned from
397 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
400 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
403 void ZOOM_resultset_destroy(ZOOM_resultset r);
406 Function <function>ZOOM_connection_search</function> creates
407 a result set given a connection and query.
408 Destroy a result set by calling
409 <function>ZOOM_resultset_destroy</function>.
410 Simple clients may using PQF only may use function
411 <function>ZOOM_connection_search_pqf</function> in which case
412 creating query objects is not necessary.
415 void ZOOM_resultset_option_set (ZOOM_resultset r,
419 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
422 size_t ZOOM_resultset_size (ZOOM_resultset r);
425 Functions <function>ZOOM_resultset_options_set</function> and
426 <function>ZOOM_resultset_get</function> sets and gets an option
427 for a result set similar to <function>ZOOM_connection_option_get</function>
428 and <function>ZOOM_connection_option_set</function>.
431 The number of hits also called result-count is returned by
432 function <function>ZOOM_resultset_size</function>.
434 <table id="zoom.resultset.options"
435 frame="top"><title>ZOOM Result set Options</title>
437 <colspec colwidth="4*" colname="name"></colspec>
438 <colspec colwidth="7*" colname="description"></colspec>
439 <colspec colwidth="2*" colname="default"></colspec>
442 <entry>Option</entry>
443 <entry>Description</entry>
444 <entry>Default</entry>
449 start</entry><entry>Offset of first record to be
450 retrieved from target. First record has offset 0 unlike the
451 protocol specifications where first record has position 1.
452 </entry><entry>0</entry></row>
454 count</entry><entry>Number of records to be retrieved.
455 </entry><entry>0</entry></row>
457 presentChunk</entry><entry>The number of records to be
458 requested from the server in each chunk (present requst). The
459 value 0 means to request all the records in a single chunk.
460 (The old <literal>step</literal>
461 option is also supported for the benefit of old applications.)
462 </entry><entry>0</entry></row>
464 elementSetName</entry><entry>Element-Set name of records.
465 Most targets should honor element set name <literal>B</literal>
466 and <literal>F</literal> for brief and full respectively.
467 </entry><entry>none</entry></row>
469 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
470 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
471 </entry><entry>none</entry></row>
473 schema</entry><entry>Schema for retrieval, such as
474 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
475 </entry><entry>none</entry></row>
477 setname</entry><entry>Name of Result Set (Result Set ID).
478 If this option isn't set, the ZOOM module will automatically
479 allocate a result set name.
480 </entry><entry>default</entry></row>
482 rpnCharset</entry><entry>Character set for RPN terms.
483 If this is set, ZOOM C will assume that the ZOOM application is
484 running UTF-8. Terms in RPN queries are then converted to the
485 rpnCharset. If this is unset, ZOOM C will not assume any encoding
486 of RPN terms and no conversion is performed.
487 </entry><entry>none</entry></row>
492 For servers that support Search Info report, the following
493 options may be read using <function>ZOOM_resultset_get</function>.
494 This detailed information is read after a successful search has
498 This information is a list of of items, where each item is
499 information about a term or subquery. All items in the list
501 <literal>SearchResult.</literal><replaceable>no</replaceable>
502 where no presents the item number (0=first, 1=second).
503 Read <literal>searchresult.size</literal> to determine the
506 <table id="zoom.search.info.report.options"
507 frame="top"><title>Search Info Report Options</title>
509 <colspec colwidth="4*" colname="name"></colspec>
510 <colspec colwidth="7*" colname="description"></colspec>
513 <entry>Option</entry>
514 <entry>Description</entry>
519 <entry>searchresult.size</entry>
521 number of search result entries. This option is-nonexistant
522 if no entries are returned by the server.
526 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
527 <entry>sub query ID</entry>
530 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
531 <entry>result count for item (number of hits)</entry>
534 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
535 <entry>subquery term</entry>
539 searchresult.<replaceable>no</replaceable>.interpretation.term
541 <entry>interpretation term</entry>
545 searchresult.<replaceable>no</replaceable>.recommendation.term
547 <entry>recommendation term</entry>
552 <sect2 id="zoom.z3950.resultset.behavior">
553 <title>Z39.50 Protocol behavior</title>
555 The creation of a result set involves at least a SearchRequest
556 - SearchResponse protocol handshake. Following that, if a sort
557 criteria was specified as part of the query, a SortRequest -
558 SortResponse handshake takes place. Note that it is necessary to
559 perform sorting before any retrieval takes place, so no records will
560 be returned from the target as part of the SearchResponse because these
561 would be unsorted. Hence, piggyback is disabled when sort criteria
562 are set. Following Search - and a possible sort - Retrieval takes
563 place - as one or more Present Requests/Response pairs being
567 The API allows for two different modes for retrieval. A high level
568 mode which is somewhat more powerful and a low level one.
569 The low level is enabled when searching on a Connection object
570 for which the settings
571 <literal>smallSetUpperBound</literal>,
572 <literal>mediumSetPresentNumber</literal> and
573 <literal>largeSetLowerBound</literal> are set. The low level mode
574 thus allows you to precisely set how records are returned as part
575 of a search response as offered by the Z39.50 protocol.
576 Since the client may be retrieving records as part of the
577 search response, this mode doesn't work well if sorting is used.
580 The high-level mode allows you to fetch a range of records from
581 the result set with a given start offset. When you use this mode
582 the client will automatically use piggyback if that is possible
583 with the target and perform one or more present requests as needed.
584 Even if the target returns fewer records as part of a present response
585 because of a record size limit, etc. the client will repeat sending
586 present requests. As an example, if option <literal>start</literal>
587 is 0 (default) and <literal>count</literal> is 4, and
588 <literal>piggyback</literal> is 1 (default) and no sorting criteria
589 is specified, then the client will attempt to retrieve the 4
590 records as part the search response (using piggyback). On the other
591 hand, if either <literal>start</literal> is positive or if
592 a sorting criteria is set, or if <literal>piggyback</literal>
593 is 0, then the client will not perform piggyback but send Present
597 If either of the options <literal>mediumSetElementSetName</literal> and
598 <literal>smallSetElementSetName</literal> are unset, the value
599 of option <literal>elementSetName</literal> is used for piggyback
600 searches. This means that for the high-level mode you only have
601 to specify one elementSetName option rather than three.
604 <sect2 id="zoom.sru.resultset.behavior">
605 <title>SRU Protocol behavior</title>
607 Current version of &yaz; does not take advantage of a result set id
608 returned by the SRU server. Future versions might do, however.
609 Since, the ZOOM driver does not save result set IDs any
610 present (retrieval) is transformed to a SRU SearchRetrieveRequest
611 with same query but, possibly, different offsets.
614 Option <literal>schema</literal> specifies SRU schema
615 for retrieval. However, options <literal>elementSetName</literal> and
616 <literal>preferredRecordSyntax</literal> are ignored.
619 Options <literal>start</literal> and <literal>count</literal>
620 are supported by SRU.
621 The remaining options
622 <literal>piggyback</literal>,
623 <literal>smallSetUpperBound</literal>,
624 <literal>largeSetLowerBound</literal>,
625 <literal>mediumSetPresentNumber</literal>,
626 <literal>mediumSetElementSetName</literal>,
627 <literal>smallSetElementSetName</literal> are
631 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
632 If PQF is used, however, the PQF query is transferred anyway
633 using non-standard element <literal>pQuery</literal> in
634 SRU SearchRetrieveRequest.
637 Unfortunately, SRU does not define a database setting. Hence,
638 <literal>databaseName</literal> is unsupported and ignored.
639 However, the path part in host parameter for functions
640 <function>ZOOM_connecton_new</function> and
641 <function>ZOOM_connection_connect</function> acts as a
642 database (at least for the &yaz; SRU server).
646 <sect1 id="zoom.records"><title>Records</title>
648 A record object is a retrieval record on the client side -
649 created from result sets.
652 void ZOOM_resultset_records(ZOOM_resultset r,
654 size_t start, size_t count);
655 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
657 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
660 int ZOOM_record_error(ZOOM_record rec, const char **msg,
661 const char **addinfo, const char **diagset);
663 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
665 void ZOOM_record_destroy (ZOOM_record rec);
668 References to temporary records are returned by functions
669 <function>ZOOM_resultset_records</function> or
670 <function>ZOOM_resultset_record</function>.
673 If a persistent reference to a record is desired
674 <function>ZOOM_record_clone</function> should be used.
675 It returns a record reference that should be destroyed
676 by a call to <function>ZOOM_record_destroy</function>.
679 A single record is returned by function
680 <function>ZOOM_resultset_record</function> that takes a
681 position as argument. First record has position zero.
682 If no record could be obtained <literal>NULL</literal> is returned.
685 Error information for a record can be checked with
686 <function>ZOOM_record_error</function> which returns non-zero
687 (error code) if record is in error, called <emphasis>Surrogate
688 Diagnostics</emphasis> in Z39.50.
691 Function <function>ZOOM_resultset_records</function> retrieves
692 a number of records from a result set. Parameter <literal>start</literal>
693 and <literal>count</literal> specifies the range of records to
694 be returned. Upon completion array
695 <literal>recs[0], ..recs[count-1]</literal>
696 holds record objects for the records. The array of records
697 <literal>recs</literal> should be allocated prior the call
698 <function>ZOOM_resultset_records</function>. Note that for those
699 records that couldn't be retrieved from the target
700 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
702 <para id="zoom.record.get">
703 In order to extract information about a single record,
704 <function>ZOOM_record_get</function> is provided. The
705 function returns a pointer to certain record information. The
706 nature (type) of the pointer depends on the parameter,
707 <parameter>type</parameter>.
710 The <parameter>type</parameter> is a string of the format:
713 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
716 where <replaceable>form</replaceable> specifies the format of the
717 returned record, <replaceable>from</replaceable>
718 specifies the character set of the record in its original form
719 (as returned by the server), <replaceable>to</replaceable> specifies
720 the output (returned)
721 character set encoding.
722 If charset is not given, then no character set conversion takes place.
723 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
726 In addition, for certain types, the length
727 <literal>len</literal> passed will be set to the size in bytes of
728 the returned information.
731 The following are the supported values for <replaceable>form</replaceable>.
733 <varlistentry><term><literal>database</literal></term>
734 <listitem><para>Database of record is returned
735 as a C null-terminated string. Return type
736 <literal>const char *</literal>.
739 <varlistentry><term><literal>syntax</literal></term>
740 <listitem><para>The transfer syntax of the record is returned
741 as a C null-terminated string containing the symbolic name of
742 the record syntax, e.g. <literal>Usmarc</literal>. Return type
744 <literal>const char *</literal>.
747 <varlistentry><term><literal>render</literal></term>
748 <listitem><para>The record is returned in a display friendly
749 format. Upon completion buffer is returned
750 (type <literal>const char *</literal>) and length is stored in
751 <literal>*len</literal>.
754 <varlistentry><term><literal>raw</literal></term>
755 <listitem><para>The record is returned in the internal
756 YAZ specific format. For GRS-1, Explain, and others, the
757 raw data is returned as type
758 <literal>Z_External *</literal> which is just the type for
759 the member <literal>retrievalRecord</literal> in
760 type <literal>NamePlusRecord</literal>.
761 For SUTRS and octet aligned record (including all MARCs) the
762 octet buffer is returned and the length of the buffer.
765 <varlistentry><term><literal>xml</literal></term>
766 <listitem><para>The record is returned in XML if possible.
767 SRU and Z39.50 records with transfer syntax XML are
768 returned verbatim. MARC records are returned in
769 <ulink url="&url.marcxml;">
772 (converted from ISO2709 to MARCXML by YAZ).
773 GRS-1 and OPAC records are not supported for this form.
774 Upon completion, the XML buffer is returned
775 (type <literal>const char *</literal>) and length is stored in
776 <literal>*len</literal>.
779 <varlistentry><term><literal>opac</literal></term>
780 <listitem><para>OPAC for record is returned in XML.
787 <ulink url="&url.marc21;">MARC21</ulink>
789 <ulink url="&url.marc8;">MARC-8</ulink>
790 character set encoding.
791 An application that wishes to display in Latin-1 would use
793 render; charset=marc8,iso-8859-1
796 <sect2 id="zoom.z3950.record.behavior">
797 <title>Z39.50 Protocol behavior</title>
799 The functions <function>ZOOM_resultset_record</function> and
800 <function>ZOOM_resultset_records</function> inspects the client-side
801 record cache. Records not found in cache are fetched using
803 The functions may block (and perform network I/O) - even though option
804 <literal>async</literal> is 1, because they return records objects.
805 (and there's no way to return records objects without retrieving them!).
808 There is a trick, however, in the usage of function
809 <function>ZOOM_resultset_records</function> that allows for
810 delayed retrieval (and makes it non-blocking). By using
811 a null pointer for <parameter>recs</parameter> you're indicating
812 you're not interested in getting records objects
813 <emphasis>now</emphasis>.
816 <sect2 id="zoom.sru.record.behavior">
817 <title>SRU Protocol behavior</title>
819 The ZOOM driver for SRU treats records returned by a SRU server
820 as if they where Z39.50 records with transfer syntax XML and
821 no element set name or database name.
825 <sect1 id="zoom.scan"><title>Scan</title>
827 This section describes an interface for Scan. Scan is not an
828 official part of the ZOOM model yet. The result of a scan operation
829 is the <literal>ZOOM_scanset</literal> which is a set of terms
830 returned by a target.
834 The Scan interface is Z39.50 only. SRW version 1.0 does not
839 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
840 const char *startpqf);
842 size_t ZOOM_scanset_size(ZOOM_scanset scan);
844 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
845 int *occ, size_t *len);
847 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
848 int *occ, size_t *len);
850 void ZOOM_scanset_destroy (ZOOM_scanset scan);
852 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
855 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
859 The scan set is created by function
860 <function>ZOOM_connection_scan</function> which performs a scan
861 operation on the connection using the specified
862 <parameter>startpqf</parameter>.
863 If the operation was successful, the size of the scan set can be
864 retrieved by a call to <function>ZOOM_scanset_size</function>.
865 Like result sets, the items are numbered 0,..size-1.
866 To obtain information about a particular scan term, call function
867 <function>ZOOM_scanset_term</function>. This function takes
868 a scan set offset <literal>pos</literal> and returns a pointer
869 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
871 If present, the <literal>occ</literal> and <literal>len</literal>
872 are set to the number of occurrences and the length
873 of the actual term respectively.
874 <function>ZOOM_scanset_display_term</function> is similar to
875 <function>ZOOM_scanset_term</function> except that it returns
876 the <emphasis>display term</emphasis> rather than the raw term.
877 In a few cases, the term is different from display term. Always
878 use the display term for display and the raw term for subsequent
879 scan operations (to get more terms, next scan result, etc).
882 A scan set may be freed by a call to function
883 <function>ZOOM_scanset_destroy</function>.
884 Functions <function>ZOOM_scanset_option_get</function> and
885 <function>ZOOM_scanset_option_set</function> retrieves and sets
886 an option respectively.
890 The <parameter>startpqf</parameter> is a subset of PQF, namely
891 the Attributes+Term part. Multiple <literal>@attr</literal> can
892 be used. For example to scan in title (complete) phrases:
894 @attr 1=4 @attr 6=2 "science o"
898 <table frame="top" id="zoom.scanset.options">
899 <title>ZOOM Scan Set Options</title>
901 <colspec colwidth="4*" colname="name"></colspec>
902 <colspec colwidth="7*" colname="description"></colspec>
903 <colspec colwidth="2*" colname="default"></colspec>
906 <entry>Option</entry>
907 <entry>Description</entry>
908 <entry>Default</entry>
913 number</entry><entry>Number of Scan Terms requested in next scan.
914 After scan it holds the actual number of terms returned.
915 </entry><entry>10</entry></row>
917 position</entry><entry>Preferred Position of term in response
918 in next scan; actual position after completion of scan.
919 </entry><entry>1</entry></row>
921 stepSize</entry><entry>Step Size
922 </entry><entry>0</entry></row>
924 scanStatus</entry><entry>An integer indicating the Scan Status
926 </entry><entry>0</entry></row>
928 rpnCharset</entry><entry>Character set for RPN terms.
929 If this is set, ZOOM C will assume that the ZOOM application is
930 running UTF-8. Terms in RPN queries are then converted to the
931 rpnCharset. If this is unset, ZOOM C will not assume any encoding
932 of RPN terms and no conversion is performed.
933 </entry><entry>none</entry></row>
939 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
941 ZOOM offers an interface to a subset of the Z39.50 extended services
942 as well as a few privately defined ones:
947 Z39.50 Item Order (ILL).
948 See <xref linkend="zoom.item.order"/>.
953 Record Update. This allows a client to insert, modify or delete
955 See <xref linkend="zoom.record.update"/>.
960 Database Create. This a non-standard feature. Allows a client
961 to create a database.
962 See <xref linkend="zoom.database.create"/>.
967 Database Drop. This a non-standard feature. Allows a client
968 to delete/drop a database.
969 See <xref linkend="zoom.database.drop"/>.
974 Commit operation. This a non-standard feature. Allows a client
975 to commit operations.
976 See <xref linkend="zoom.commit"/>.
979 <!-- all the ILL PDU options should go here too -->
982 To create an extended service operation a <literal>ZOOM_package</literal>
983 must be created. The operation is a five step operation. The
984 package is created, package is configured by means of options,
985 the package is send, result is inspected (by means of options),
986 the package is destroyed.
989 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
990 ZOOM_options options);
992 const char *ZOOM_package_option_get(ZOOM_package p,
994 void ZOOM_package_option_set(ZOOM_package p, const char *key,
996 void ZOOM_package_send(ZOOM_package p, const char *type);
998 void ZOOM_package_destroy(ZOOM_package p);
1001 The <function>ZOOM_connection_package</function> creates a
1002 package for the connection given using the options specified.
1005 Functions <function>ZOOM_package_option_get</function> and
1006 <function>ZOOM_package_option_set</function> gets and sets
1010 <function>ZOOM_package_send</function> sends
1011 the package the via connection specified in
1012 <function>ZOOM_connection_package</function>.
1013 The <parameter>type</parameter> specifies the actual extended service
1014 package type to be sent.
1017 <table frame="top" id="zoom.extendedservices.options">
1018 <title>Extended Service Common Options</title>
1020 <colspec colwidth="4*" colname="name"></colspec>
1021 <colspec colwidth="7*" colname="description"></colspec>
1022 <colspec colwidth="3*" colname="default"></colspec>
1025 <entry>Option</entry>
1026 <entry>Description</entry>
1027 <entry>Default</entry>
1032 <entry>package-name</entry>
1033 <entry>Extended Service Request package name. Must be specified
1034 as part of a request</entry>
1038 <entry>user-id</entry>
1039 <entry>User ID of Extended Service Package. Is a request option</entry>
1043 <entry>function</entry>
1045 Function of package - one of <literal>create</literal>,
1046 <literal>delete</literal>, <literal>modify</literal>. Is
1049 <entry><literal>create</literal></entry>
1052 <entry>waitAction</entry>
1054 Wait action for package. Possible values:
1055 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1056 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1058 <entry><literal>waitIfPossible</literal></entry>
1061 <entry>targetReference</entry>
1063 Target Reference. This is part of the response as returned
1064 by the server. Read it after a successful operation.
1066 <entry><literal>none</literal></entry>
1072 <sect2 id="zoom.item.order"><title>Item Order</title>
1074 For Item Order, type must be set to <literal>itemorder</literal> in
1075 <function>ZOOM_package_send</function>.
1078 <table frame="top" id="zoom.item.order.options">
1079 <title>Item Order Options</title>
1081 <colspec colwidth="4*" colname="name"></colspec>
1082 <colspec colwidth="7*" colname="description"></colspec>
1083 <colspec colwidth="3*" colname="default"></colspec>
1086 <entry>Option</entry>
1087 <entry>Description</entry>
1088 <entry>Default</entry>
1093 <entry>contact-name</entry>
1094 <entry>ILL contact name</entry>
1098 <entry>contact-phone</entry>
1099 <entry>ILL contact phone</entry>
1103 <entry>contact-email</entry>
1104 <entry>ILL contact email</entry>
1108 <entry>itemorder-item</entry>
1109 <entry>Position for item (record) requested. An integer</entry>
1118 <sect2 id="zoom.record.update"><title>Record Update</title>
1120 For Record Update, type must be set to <literal>update</literal> in
1121 <function>ZOOM_package_send</function>.
1124 <table frame="top" id="zoom.record.update.options">
1125 <title>Record Update Options</title>
1127 <colspec colwidth="4*" colname="name"></colspec>
1128 <colspec colwidth="7*" colname="description"></colspec>
1129 <colspec colwidth="3*" colname="default"></colspec>
1132 <entry>Option</entry>
1133 <entry>Description</entry>
1134 <entry>Default</entry>
1139 <entry>action</entry>
1141 The update action. One of
1142 <literal>specialUpdate</literal>,
1143 <literal>recordInsert</literal>,
1144 <literal>recordReplace</literal>,
1145 <literal>recordDelete</literal>,
1146 <literal>elementUpdate</literal>.
1148 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1151 <entry>recordIdOpaque</entry>
1152 <entry>Opaque Record ID</entry>
1156 <entry>recordIdNumber</entry>
1157 <entry>Record ID number</entry>
1161 <entry>record</entry>
1162 <entry>The record itself</entry>
1166 <entry>syntax</entry>
1167 <entry>The record syntax (transfer syntax). Is a string that
1168 is a known record syntax.
1170 <entry>no syntax</entry>
1173 <entry>databaseName</entry>
1174 <entry>Database from connection object</entry>
1175 <entry>Default</entry>
1178 <entry>correlationInfo.note</entry>
1179 <entry>Correlation Info Note (string)</entry>
1183 <entry>correlationInfo.id</entry>
1184 <entry>Correlation Info ID (integer)</entry>
1188 <entry>elementSetName</entry>
1189 <entry>Element Set for Record</entry>
1193 <entry>updateVersion</entry>
1194 <entry>Record Update version which holds one of the values
1195 1, 2 or 3. Each version has a distinct OID:
1197 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1199 (second version) and
1200 1.2.840.10003.9.5.1.1
1201 (<ulink url="&url.z39.50.extupdate3;">third and
1202 newest version</ulink>).
1212 <sect2 id="zoom.database.create"><title>Database Create</title>
1214 For Database Create, type must be set to <literal>create</literal> in
1215 <function>ZOOM_package_send</function>.
1218 <table frame="top" id="zoom.database.create.options">
1219 <title>Database Create Options</title>
1221 <colspec colwidth="4*" colname="name"></colspec>
1222 <colspec colwidth="7*" colname="description"></colspec>
1223 <colspec colwidth="3*" colname="default"></colspec>
1226 <entry>Option</entry>
1227 <entry>Description</entry>
1228 <entry>Default</entry>
1233 <entry>databaseName</entry>
1234 <entry>Database from connection object</entry>
1235 <entry>Default</entry>
1242 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1244 For Database Drop, type must be set to <literal>drop</literal> in
1245 <function>ZOOM_package_send</function>.
1248 <table frame="top" id="zoom.database.drop.options">
1249 <title>Database Drop Options</title>
1251 <colspec colwidth="4*" colname="name"></colspec>
1252 <colspec colwidth="7*" colname="description"></colspec>
1253 <colspec colwidth="3*" colname="default"></colspec>
1256 <entry>Option</entry>
1257 <entry>Description</entry>
1258 <entry>Default</entry>
1263 <entry>databaseName</entry>
1264 <entry>Database from connection object</entry>
1265 <entry>Default</entry>
1272 <sect2 id="zoom.commit"><title>Commit Operation</title>
1274 For Commit, type must be set to <literal>commit</literal> in
1275 <function>ZOOM_package_send</function>.
1279 <sect2 id="zoom.extended.services.behavior">
1280 <title>Protocol behavior</title>
1282 All the extended services are Z39.50-only.
1286 The database create, drop and commit services are privately defined
1288 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1295 <sect1 id="zoom.options"><title>Options</title>
1297 Most &zoom; objects provide a way to specify options to change behavior.
1298 From an implementation point of view a set of options is just like
1299 an associative array / hash.
1302 ZOOM_options ZOOM_options_create (void);
1304 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1306 void ZOOM_options_destroy (ZOOM_options opt);
1309 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1311 void ZOOM_options_set (ZOOM_options opt, const char *name,
1315 typedef const char *(*ZOOM_options_callback)
1316 (void *handle, const char *name);
1318 ZOOM_options_callback
1319 ZOOM_options_set_callback (ZOOM_options opt,
1320 ZOOM_options_callback c,
1324 <sect1 id="zoom.events"><title>Events</title>
1326 If you're developing non-blocking applications, you have to deal
1330 int ZOOM_event (int no, ZOOM_connection *cs);
1333 The <function>ZOOM_event</function> executes pending events for
1334 a number of connections. Supply the number of connections in
1335 <literal>no</literal> and an array of connections in
1336 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1337 A pending event could be a sending a search, receiving a response,
1339 When an event has occurred for one of the connections, this function
1340 returns a positive integer <literal>n</literal> denoting that an event
1341 occurred for connection <literal>cs[n-1]</literal>.
1342 When no events are pending for the connections, a value of zero is
1344 To ensure that all outstanding requests are performed call this function
1345 repeatedly until zero is returned.
1348 If <function>ZOOM_event</function> returns and returns non-zero, the
1349 last event that occurred can be expected.
1352 int ZOOM_connection_last_event(ZOOM_connection cs);
1355 <function>ZOOM_connection_last_event</function> returns an event type
1356 (integer) for the last event.
1359 <table frame="top" id="zoom.event.ids">
1360 <title>ZOOM Event IDs</title>
1362 <colspec colwidth="4*" colname="name"></colspec>
1363 <colspec colwidth="7*" colname="description"></colspec>
1366 <entry>Event</entry>
1367 <entry>Description</entry>
1372 <entry>ZOOM_EVENT_NONE</entry>
1373 <entry>No event has occurred</entry>
1376 <entry>ZOOM_EVENT_CONNECT</entry>
1377 <entry>TCP/IP connect has initiated</entry>
1380 <entry>ZOOM_EVENT_SEND_DATA</entry>
1381 <entry>Data has been transmitted (sending)</entry>
1384 <entry>ZOOM_EVENT_RECV_DATA</entry>
1385 <entry>Data has been received)</entry>
1388 <entry>ZOOM_EVENT_TIMEOUT</entry>
1389 <entry>Timeout</entry>
1392 <entry>ZOOM_EVENT_UNKNOWN</entry>
1393 <entry>Unknown event</entry>
1396 <entry>ZOOM_EVENT_SEND_APDU</entry>
1397 <entry>An APDU has been transmitted (sending)</entry>
1400 <entry>ZOOM_EVENT_RECV_APDU</entry>
1401 <entry>An APDU has been received</entry>
1404 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1405 <entry>A result-set record has been received</entry>
1408 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1409 <entry>A search result been received</entry>
1417 <!-- Keep this comment at the end of the file
1422 sgml-minimize-attributes:nil
1423 sgml-always-quote-attributes:t
1426 sgml-parent-document: "yaz.xml"
1427 sgml-local-catalogs: nil
1428 sgml-namecase-general:t