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 1.65 2007-09-11 16:36:51 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>
271 sru_version</entry><entry>
272 SRU/SRW version. Should be <literal>1.1</literal>, or
273 <literal>1.2</literal>. This is , prior to connect, the version
274 to offer (highest version). And following connect (in fact
275 first operation), holds the negotiated version with the server
276 (same or lower version).
277 </entry><entry>1.2</entry></row>
282 If either option <literal>lang</literal> or <literal>charset</literal>
284 <ulink url="&url.z39.50.charneg;">
285 Character Set and Language Negotiation</ulink> is in effect.
288 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
289 const char **addinfo);
290 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
291 const char **addinfo, const char **dset);
294 Function <function>ZOOM_connection_error</function> checks for
295 errors for the last operation(s) performed. The function returns
296 zero if no errors occurred; non-zero otherwise indicating the error.
297 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
298 holds messages for the error and additional-info if passed as
299 non-<literal>NULL</literal>. Function
300 <function>ZOOM_connection_error_x</function> is an extended version
301 of <function>ZOOM_connection_error</function> that is capable of
302 returning name of diagnostic set in <parameter>dset</parameter>.
304 <sect2 id="zoom-connection-z39.50">
305 <title>Z39.50 Protocol behavior</title>
307 The calls <function>ZOOM_connection_new</function> and
308 <function>ZOOM_connection_connect</function> establishes a TCP/IP
309 connection and sends an Initialize Request to the target if
310 possible. In addition, the calls waits for an Initialize Response
311 from the target and the result is inspected (OK or rejected).
314 If <literal>proxy</literal> is set then the client will establish
315 a TCP/IP connection with the peer as specified by the
316 <literal>proxy</literal> host and the hostname as part of the
317 connect calls will be set as part of the Initialize Request.
318 The proxy server will then "forward" the PDU's transparently
319 to the target behind the proxy.
322 For the authentication parameters, if option <literal>user</literal>
323 is set and both options <literal>group</literal> and
324 <literal>pass</literal> are unset, then Open style
325 authentication is used (Version 2/3) in which case the username
326 is usually followed by a slash, then by a password.
327 If either <literal>group</literal>
328 or <literal>pass</literal> is set then idPass authentication
329 (Version 3 only) is used. If none of the options are set, no
330 authentication parameters are set as part of the Initialize Request
334 When option <literal>async</literal> is 1, it really means that
335 all network operations are postponed (and queued) until the
336 function <literal>ZOOM_event</literal> is invoked. When doing so
337 it doesn't make sense to check for errors after
338 <literal>ZOOM_connection_new</literal> is called since that
339 operation "connecting - and init" is still incomplete and the
340 API cannot tell the outcome (yet).
343 <sect2 id="zoom.sru.init.behavior">
344 <title>SRU Protocol behavior</title>
346 The SRU protocol doesn't feature an Inititialize Request, so
347 the connection phase merely establishes a TCP/IP connection
348 with the SOAP service.
350 <para>Most of the ZOOM connection options do not
351 affect SRU and they are ignored. However, future versions
352 of &yaz; might honor <literal>implementationName</literal> and
353 put that as part of User-Agent header for HTTP requests.
356 The <literal>charset</literal> is used in the Content-Type header
361 <sect1 id="zoom.query"><title>Queries</title>
363 Query objects represents queries.
366 ZOOM_query ZOOM_query_create(void);
368 void ZOOM_query_destroy(ZOOM_query q);
370 int ZOOM_query_prefix(ZOOM_query q, const char *str);
372 int ZOOM_query_cql(ZOOM_query s, const char *str);
374 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
377 Create query objects using <function>ZOOM_query_create</function>
378 and destroy them by calling <function>ZOOM_query_destroy</function>.
379 RPN-queries can be specified in <link linkend="PQF">PQF</link>
380 notation by using the
381 function <function>ZOOM_query_prefix</function>.
382 The <function>ZOOM_query_cql</function> specifies a CQL
383 query to be sent to the server/target.
384 More query types will be added in future versions of &yaz;, such as
385 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
386 etc. In addition to a search, a sort criteria may be set. Function
387 <function>ZOOM_query_sortby</function> specifies a
388 sort criteria using the same string notation for sort as offered by
389 the <link linkend="sortspec">YAZ client</link>.
391 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
393 The query object is just an interface for the member Query
394 in the SearchRequest. The sortby-function is an interface to the
395 sortSequence member of the SortRequest.
399 <sect1 id="zoom.resultsets"><title>Result sets</title>
401 The result set object is a container for records returned from
405 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
408 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
411 void ZOOM_resultset_destroy(ZOOM_resultset r);
414 Function <function>ZOOM_connection_search</function> creates
415 a result set given a connection and query.
416 Destroy a result set by calling
417 <function>ZOOM_resultset_destroy</function>.
418 Simple clients may using PQF only may use function
419 <function>ZOOM_connection_search_pqf</function> in which case
420 creating query objects is not necessary.
423 void ZOOM_resultset_option_set (ZOOM_resultset r,
427 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
430 size_t ZOOM_resultset_size (ZOOM_resultset r);
433 Functions <function>ZOOM_resultset_options_set</function> and
434 <function>ZOOM_resultset_get</function> sets and gets an option
435 for a result set similar to <function>ZOOM_connection_option_get</function>
436 and <function>ZOOM_connection_option_set</function>.
439 The number of hits also called result-count is returned by
440 function <function>ZOOM_resultset_size</function>.
442 <table id="zoom.resultset.options"
443 frame="top"><title>ZOOM Result set Options</title>
445 <colspec colwidth="4*" colname="name"></colspec>
446 <colspec colwidth="7*" colname="description"></colspec>
447 <colspec colwidth="2*" colname="default"></colspec>
450 <entry>Option</entry>
451 <entry>Description</entry>
452 <entry>Default</entry>
457 start</entry><entry>Offset of first record to be
458 retrieved from target. First record has offset 0 unlike the
459 protocol specifications where first record has position 1.
460 </entry><entry>0</entry></row>
462 count</entry><entry>Number of records to be retrieved.
463 </entry><entry>0</entry></row>
465 presentChunk</entry><entry>The number of records to be
466 requested from the server in each chunk (present requst). The
467 value 0 means to request all the records in a single chunk.
468 (The old <literal>step</literal>
469 option is also supported for the benefit of old applications.)
470 </entry><entry>0</entry></row>
472 elementSetName</entry><entry>Element-Set name of records.
473 Most targets should honor element set name <literal>B</literal>
474 and <literal>F</literal> for brief and full respectively.
475 </entry><entry>none</entry></row>
477 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
478 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
479 </entry><entry>none</entry></row>
481 schema</entry><entry>Schema for retrieval, such as
482 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
483 </entry><entry>none</entry></row>
485 setname</entry><entry>Name of Result Set (Result Set ID).
486 If this option isn't set, the ZOOM module will automatically
487 allocate a result set name.
488 </entry><entry>default</entry></row>
490 rpnCharset</entry><entry>Character set for RPN terms.
491 If this is set, ZOOM C will assume that the ZOOM application is
492 running UTF-8. Terms in RPN queries are then converted to the
493 rpnCharset. If this is unset, ZOOM C will not assume any encoding
494 of RPN terms and no conversion is performed.
495 </entry><entry>none</entry></row>
500 For servers that support Search Info report, the following
501 options may be read using <function>ZOOM_resultset_get</function>.
502 This detailed information is read after a successful search has
506 This information is a list of of items, where each item is
507 information about a term or subquery. All items in the list
509 <literal>SearchResult.</literal><replaceable>no</replaceable>
510 where no presents the item number (0=first, 1=second).
511 Read <literal>searchresult.size</literal> to determine the
514 <table id="zoom.search.info.report.options"
515 frame="top"><title>Search Info Report Options</title>
517 <colspec colwidth="4*" colname="name"></colspec>
518 <colspec colwidth="7*" colname="description"></colspec>
521 <entry>Option</entry>
522 <entry>Description</entry>
527 <entry>searchresult.size</entry>
529 number of search result entries. This option is-nonexistant
530 if no entries are returned by the server.
534 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
535 <entry>sub query ID</entry>
538 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
539 <entry>result count for item (number of hits)</entry>
542 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
543 <entry>subquery term</entry>
547 searchresult.<replaceable>no</replaceable>.interpretation.term
549 <entry>interpretation term</entry>
553 searchresult.<replaceable>no</replaceable>.recommendation.term
555 <entry>recommendation term</entry>
560 <sect2 id="zoom.z3950.resultset.behavior">
561 <title>Z39.50 Protocol behavior</title>
563 The creation of a result set involves at least a SearchRequest
564 - SearchResponse protocol handshake. Following that, if a sort
565 criteria was specified as part of the query, a SortRequest -
566 SortResponse handshake takes place. Note that it is necessary to
567 perform sorting before any retrieval takes place, so no records will
568 be returned from the target as part of the SearchResponse because these
569 would be unsorted. Hence, piggyback is disabled when sort criteria
570 are set. Following Search - and a possible sort - Retrieval takes
571 place - as one or more Present Requests/Response pairs being
575 The API allows for two different modes for retrieval. A high level
576 mode which is somewhat more powerful and a low level one.
577 The low level is enabled when searching on a Connection object
578 for which the settings
579 <literal>smallSetUpperBound</literal>,
580 <literal>mediumSetPresentNumber</literal> and
581 <literal>largeSetLowerBound</literal> are set. The low level mode
582 thus allows you to precisely set how records are returned as part
583 of a search response as offered by the Z39.50 protocol.
584 Since the client may be retrieving records as part of the
585 search response, this mode doesn't work well if sorting is used.
588 The high-level mode allows you to fetch a range of records from
589 the result set with a given start offset. When you use this mode
590 the client will automatically use piggyback if that is possible
591 with the target and perform one or more present requests as needed.
592 Even if the target returns fewer records as part of a present response
593 because of a record size limit, etc. the client will repeat sending
594 present requests. As an example, if option <literal>start</literal>
595 is 0 (default) and <literal>count</literal> is 4, and
596 <literal>piggyback</literal> is 1 (default) and no sorting criteria
597 is specified, then the client will attempt to retrieve the 4
598 records as part the search response (using piggyback). On the other
599 hand, if either <literal>start</literal> is positive or if
600 a sorting criteria is set, or if <literal>piggyback</literal>
601 is 0, then the client will not perform piggyback but send Present
605 If either of the options <literal>mediumSetElementSetName</literal> and
606 <literal>smallSetElementSetName</literal> are unset, the value
607 of option <literal>elementSetName</literal> is used for piggyback
608 searches. This means that for the high-level mode you only have
609 to specify one elementSetName option rather than three.
612 <sect2 id="zoom.sru.resultset.behavior">
613 <title>SRU Protocol behavior</title>
615 Current version of &yaz; does not take advantage of a result set id
616 returned by the SRU server. Future versions might do, however.
617 Since, the ZOOM driver does not save result set IDs any
618 present (retrieval) is transformed to a SRU SearchRetrieveRequest
619 with same query but, possibly, different offsets.
622 Option <literal>schema</literal> specifies SRU schema
623 for retrieval. However, options <literal>elementSetName</literal> and
624 <literal>preferredRecordSyntax</literal> are ignored.
627 Options <literal>start</literal> and <literal>count</literal>
628 are supported by SRU.
629 The remaining options
630 <literal>piggyback</literal>,
631 <literal>smallSetUpperBound</literal>,
632 <literal>largeSetLowerBound</literal>,
633 <literal>mediumSetPresentNumber</literal>,
634 <literal>mediumSetElementSetName</literal>,
635 <literal>smallSetElementSetName</literal> are
639 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
640 If PQF is used, however, the PQF query is transferred anyway
641 using non-standard element <literal>pQuery</literal> in
642 SRU SearchRetrieveRequest.
645 Unfortunately, SRU does not define a database setting. Hence,
646 <literal>databaseName</literal> is unsupported and ignored.
647 However, the path part in host parameter for functions
648 <function>ZOOM_connecton_new</function> and
649 <function>ZOOM_connection_connect</function> acts as a
650 database (at least for the &yaz; SRU server).
654 <sect1 id="zoom.records"><title>Records</title>
656 A record object is a retrieval record on the client side -
657 created from result sets.
660 void ZOOM_resultset_records(ZOOM_resultset r,
662 size_t start, size_t count);
663 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
665 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
668 int ZOOM_record_error(ZOOM_record rec, const char **msg,
669 const char **addinfo, const char **diagset);
671 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
673 void ZOOM_record_destroy (ZOOM_record rec);
676 References to temporary records are returned by functions
677 <function>ZOOM_resultset_records</function> or
678 <function>ZOOM_resultset_record</function>.
681 If a persistent reference to a record is desired
682 <function>ZOOM_record_clone</function> should be used.
683 It returns a record reference that should be destroyed
684 by a call to <function>ZOOM_record_destroy</function>.
687 A single record is returned by function
688 <function>ZOOM_resultset_record</function> that takes a
689 position as argument. First record has position zero.
690 If no record could be obtained <literal>NULL</literal> is returned.
693 Error information for a record can be checked with
694 <function>ZOOM_record_error</function> which returns non-zero
695 (error code) if record is in error, called <emphasis>Surrogate
696 Diagnostics</emphasis> in Z39.50.
699 Function <function>ZOOM_resultset_records</function> retrieves
700 a number of records from a result set. Parameter <literal>start</literal>
701 and <literal>count</literal> specifies the range of records to
702 be returned. Upon completion array
703 <literal>recs[0], ..recs[count-1]</literal>
704 holds record objects for the records. The array of records
705 <literal>recs</literal> should be allocated prior the call
706 <function>ZOOM_resultset_records</function>. Note that for those
707 records that couldn't be retrieved from the target
708 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
710 <para id="zoom.record.get">
711 In order to extract information about a single record,
712 <function>ZOOM_record_get</function> is provided. The
713 function returns a pointer to certain record information. The
714 nature (type) of the pointer depends on the parameter,
715 <parameter>type</parameter>.
718 The <parameter>type</parameter> is a string of the format:
721 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
724 where <replaceable>form</replaceable> specifies the format of the
725 returned record, <replaceable>from</replaceable>
726 specifies the character set of the record in its original form
727 (as returned by the server), <replaceable>to</replaceable> specifies
728 the output (returned)
729 character set encoding.
730 If charset is not given, then no character set conversion takes place.
731 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
734 In addition, for certain types, the length
735 <literal>len</literal> passed will be set to the size in bytes of
736 the returned information.
739 The following are the supported values for <replaceable>form</replaceable>.
741 <varlistentry><term><literal>database</literal></term>
742 <listitem><para>Database of record is returned
743 as a C null-terminated string. Return type
744 <literal>const char *</literal>.
747 <varlistentry><term><literal>syntax</literal></term>
748 <listitem><para>The transfer syntax of the record is returned
749 as a C null-terminated string containing the symbolic name of
750 the record syntax, e.g. <literal>Usmarc</literal>. Return type
752 <literal>const char *</literal>.
755 <varlistentry><term><literal>schema</literal></term>
756 <listitem><para>The schema of the record is returned
757 as a C null-terminated string. Return type is
758 <literal>const char *</literal>.
761 <varlistentry><term><literal>render</literal></term>
762 <listitem><para>The record is returned in a display friendly
763 format. Upon completion buffer is returned
764 (type <literal>const char *</literal>) and length is stored in
765 <literal>*len</literal>.
768 <varlistentry><term><literal>raw</literal></term>
769 <listitem><para>The record is returned in the internal
770 YAZ specific format. For GRS-1, Explain, and others, the
771 raw data is returned as type
772 <literal>Z_External *</literal> which is just the type for
773 the member <literal>retrievalRecord</literal> in
774 type <literal>NamePlusRecord</literal>.
775 For SUTRS and octet aligned record (including all MARCs) the
776 octet buffer is returned and the length of the buffer.
779 <varlistentry><term><literal>xml</literal></term>
780 <listitem><para>The record is returned in XML if possible.
781 SRU and Z39.50 records with transfer syntax XML are
782 returned verbatim. MARC records are returned in
783 <ulink url="&url.marcxml;">
786 (converted from ISO2709 to MARCXML by YAZ).
787 GRS-1 and OPAC records are not supported for this form.
788 Upon completion, the XML buffer is returned
789 (type <literal>const char *</literal>) and length is stored in
790 <literal>*len</literal>.
793 <varlistentry><term><literal>opac</literal></term>
794 <listitem><para>OPAC for record is returned in XML.
801 <ulink url="&url.marc21;">MARC21</ulink>
803 <ulink url="&url.marc8;">MARC-8</ulink>
804 character set encoding.
805 An application that wishes to display in Latin-1 would use
807 render; charset=marc8,iso-8859-1
810 <sect2 id="zoom.z3950.record.behavior">
811 <title>Z39.50 Protocol behavior</title>
813 The functions <function>ZOOM_resultset_record</function> and
814 <function>ZOOM_resultset_records</function> inspects the client-side
815 record cache. Records not found in cache are fetched using
817 The functions may block (and perform network I/O) - even though option
818 <literal>async</literal> is 1, because they return records objects.
819 (and there's no way to return records objects without retrieving them!).
822 There is a trick, however, in the usage of function
823 <function>ZOOM_resultset_records</function> that allows for
824 delayed retrieval (and makes it non-blocking). By using
825 a null pointer for <parameter>recs</parameter> you're indicating
826 you're not interested in getting records objects
827 <emphasis>now</emphasis>.
830 <sect2 id="zoom.sru.record.behavior">
831 <title>SRU Protocol behavior</title>
833 The ZOOM driver for SRU treats records returned by a SRU server
834 as if they where Z39.50 records with transfer syntax XML and
835 no element set name or database name.
839 <sect1 id="zoom.scan"><title>Scan</title>
841 This section describes an interface for Scan. Scan is not an
842 official part of the ZOOM model yet. The result of a scan operation
843 is the <literal>ZOOM_scanset</literal> which is a set of terms
844 returned by a target.
848 The Scan interface is supported for both Z39.50 and SRU.
852 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
853 const char *startpqf);
855 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
858 size_t ZOOM_scanset_size(ZOOM_scanset scan);
860 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
861 int *occ, size_t *len);
863 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
864 int *occ, size_t *len);
866 void ZOOM_scanset_destroy (ZOOM_scanset scan);
868 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
871 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
875 The scan set is created by function
876 <function>ZOOM_connection_scan</function> which performs a scan
877 operation on the connection using the specified
878 <parameter>startpqf</parameter>.
879 If the operation was successful, the size of the scan set can be
880 retrieved by a call to <function>ZOOM_scanset_size</function>.
881 Like result sets, the items are numbered 0,..size-1.
882 To obtain information about a particular scan term, call function
883 <function>ZOOM_scanset_term</function>. This function takes
884 a scan set offset <literal>pos</literal> and returns a pointer
885 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
887 If present, the <literal>occ</literal> and <literal>len</literal>
888 are set to the number of occurrences and the length
889 of the actual term respectively.
890 <function>ZOOM_scanset_display_term</function> is similar to
891 <function>ZOOM_scanset_term</function> except that it returns
892 the <emphasis>display term</emphasis> rather than the raw term.
893 In a few cases, the term is different from display term. Always
894 use the display term for display and the raw term for subsequent
895 scan operations (to get more terms, next scan result, etc).
898 A scan set may be freed by a call to function
899 <function>ZOOM_scanset_destroy</function>.
900 Functions <function>ZOOM_scanset_option_get</function> and
901 <function>ZOOM_scanset_option_set</function> retrieves and sets
902 an option respectively.
906 The <parameter>startpqf</parameter> is a subset of PQF, namely
907 the Attributes+Term part. Multiple <literal>@attr</literal> can
908 be used. For example to scan in title (complete) phrases:
910 @attr 1=4 @attr 6=2 "science o"
915 The <function>ZOOM_connecton_scan1</function> is a newer and
916 more generic alternative to <function>ZOOM_connection_scan</function>
917 which allows to use both CQL and PQF for Scan.
920 <table frame="top" id="zoom.scanset.options">
921 <title>ZOOM Scan Set Options</title>
923 <colspec colwidth="4*" colname="name"></colspec>
924 <colspec colwidth="7*" colname="description"></colspec>
925 <colspec colwidth="2*" colname="default"></colspec>
928 <entry>Option</entry>
929 <entry>Description</entry>
930 <entry>Default</entry>
935 number</entry><entry>Number of Scan Terms requested in next scan.
936 After scan it holds the actual number of terms returned.
937 </entry><entry>10</entry></row>
939 position</entry><entry>Preferred Position of term in response
940 in next scan; actual position after completion of scan.
941 </entry><entry>1</entry></row>
943 stepSize</entry><entry>Step Size
944 </entry><entry>0</entry></row>
946 scanStatus</entry><entry>An integer indicating the Scan Status
948 </entry><entry>0</entry></row>
950 rpnCharset</entry><entry>Character set for RPN terms.
951 If this is set, ZOOM C will assume that the ZOOM application is
952 running UTF-8. Terms in RPN queries are then converted to the
953 rpnCharset. If this is unset, ZOOM C will not assume any encoding
954 of RPN terms and no conversion is performed.
955 </entry><entry>none</entry></row>
961 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
963 ZOOM offers an interface to a subset of the Z39.50 extended services
964 as well as a few privately defined ones:
969 Z39.50 Item Order (ILL).
970 See <xref linkend="zoom.item.order"/>.
975 Record Update. This allows a client to insert, modify or delete
977 See <xref linkend="zoom.record.update"/>.
982 Database Create. This a non-standard feature. Allows a client
983 to create a database.
984 See <xref linkend="zoom.database.create"/>.
989 Database Drop. This a non-standard feature. Allows a client
990 to delete/drop a database.
991 See <xref linkend="zoom.database.drop"/>.
996 Commit operation. This a non-standard feature. Allows a client
997 to commit operations.
998 See <xref linkend="zoom.commit"/>.
1001 <!-- all the ILL PDU options should go here too -->
1004 To create an extended service operation a <literal>ZOOM_package</literal>
1005 must be created. The operation is a five step operation. The
1006 package is created, package is configured by means of options,
1007 the package is send, result is inspected (by means of options),
1008 the package is destroyed.
1011 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1012 ZOOM_options options);
1014 const char *ZOOM_package_option_get(ZOOM_package p,
1016 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1018 void ZOOM_package_send(ZOOM_package p, const char *type);
1020 void ZOOM_package_destroy(ZOOM_package p);
1023 The <function>ZOOM_connection_package</function> creates a
1024 package for the connection given using the options specified.
1027 Functions <function>ZOOM_package_option_get</function> and
1028 <function>ZOOM_package_option_set</function> gets and sets
1032 <function>ZOOM_package_send</function> sends
1033 the package the via connection specified in
1034 <function>ZOOM_connection_package</function>.
1035 The <parameter>type</parameter> specifies the actual extended service
1036 package type to be sent.
1039 <table frame="top" id="zoom.extendedservices.options">
1040 <title>Extended Service Common Options</title>
1042 <colspec colwidth="4*" colname="name"></colspec>
1043 <colspec colwidth="7*" colname="description"></colspec>
1044 <colspec colwidth="3*" colname="default"></colspec>
1047 <entry>Option</entry>
1048 <entry>Description</entry>
1049 <entry>Default</entry>
1054 <entry>package-name</entry>
1055 <entry>Extended Service Request package name. Must be specified
1056 as part of a request</entry>
1060 <entry>user-id</entry>
1061 <entry>User ID of Extended Service Package. Is a request option</entry>
1065 <entry>function</entry>
1067 Function of package - one of <literal>create</literal>,
1068 <literal>delete</literal>, <literal>modify</literal>. Is
1071 <entry><literal>create</literal></entry>
1074 <entry>waitAction</entry>
1076 Wait action for package. Possible values:
1077 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1078 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1080 <entry><literal>waitIfPossible</literal></entry>
1083 <entry>targetReference</entry>
1085 Target Reference. This is part of the response as returned
1086 by the server. Read it after a successful operation.
1088 <entry><literal>none</literal></entry>
1094 <sect2 id="zoom.item.order"><title>Item Order</title>
1096 For Item Order, type must be set to <literal>itemorder</literal> in
1097 <function>ZOOM_package_send</function>.
1100 <table frame="top" id="zoom.item.order.options">
1101 <title>Item Order Options</title>
1103 <colspec colwidth="4*" colname="name"></colspec>
1104 <colspec colwidth="7*" colname="description"></colspec>
1105 <colspec colwidth="3*" colname="default"></colspec>
1108 <entry>Option</entry>
1109 <entry>Description</entry>
1110 <entry>Default</entry>
1115 <entry>contact-name</entry>
1116 <entry>ILL contact name</entry>
1120 <entry>contact-phone</entry>
1121 <entry>ILL contact phone</entry>
1125 <entry>contact-email</entry>
1126 <entry>ILL contact email</entry>
1130 <entry>itemorder-item</entry>
1131 <entry>Position for item (record) requested. An integer</entry>
1140 <sect2 id="zoom.record.update"><title>Record Update</title>
1142 For Record Update, type must be set to <literal>update</literal> in
1143 <function>ZOOM_package_send</function>.
1146 <table frame="top" id="zoom.record.update.options">
1147 <title>Record Update Options</title>
1149 <colspec colwidth="4*" colname="name"></colspec>
1150 <colspec colwidth="7*" colname="description"></colspec>
1151 <colspec colwidth="3*" colname="default"></colspec>
1154 <entry>Option</entry>
1155 <entry>Description</entry>
1156 <entry>Default</entry>
1161 <entry>action</entry>
1163 The update action. One of
1164 <literal>specialUpdate</literal>,
1165 <literal>recordInsert</literal>,
1166 <literal>recordReplace</literal>,
1167 <literal>recordDelete</literal>,
1168 <literal>elementUpdate</literal>.
1170 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1173 <entry>recordIdOpaque</entry>
1174 <entry>Opaque Record ID</entry>
1178 <entry>recordIdNumber</entry>
1179 <entry>Record ID number</entry>
1183 <entry>record</entry>
1184 <entry>The record itself</entry>
1188 <entry>syntax</entry>
1189 <entry>The record syntax (transfer syntax). Is a string that
1190 is a known record syntax.
1192 <entry>no syntax</entry>
1195 <entry>databaseName</entry>
1196 <entry>Database from connection object</entry>
1197 <entry>Default</entry>
1200 <entry>correlationInfo.note</entry>
1201 <entry>Correlation Info Note (string)</entry>
1205 <entry>correlationInfo.id</entry>
1206 <entry>Correlation Info ID (integer)</entry>
1210 <entry>elementSetName</entry>
1211 <entry>Element Set for Record</entry>
1215 <entry>updateVersion</entry>
1216 <entry>Record Update version which holds one of the values
1217 1, 2 or 3. Each version has a distinct OID:
1219 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1221 (second version) and
1222 1.2.840.10003.9.5.1.1
1223 (<ulink url="&url.z39.50.extupdate3;">third and
1224 newest version</ulink>).
1234 <sect2 id="zoom.database.create"><title>Database Create</title>
1236 For Database Create, type must be set to <literal>create</literal> in
1237 <function>ZOOM_package_send</function>.
1240 <table frame="top" id="zoom.database.create.options">
1241 <title>Database Create Options</title>
1243 <colspec colwidth="4*" colname="name"></colspec>
1244 <colspec colwidth="7*" colname="description"></colspec>
1245 <colspec colwidth="3*" colname="default"></colspec>
1248 <entry>Option</entry>
1249 <entry>Description</entry>
1250 <entry>Default</entry>
1255 <entry>databaseName</entry>
1256 <entry>Database from connection object</entry>
1257 <entry>Default</entry>
1264 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1266 For Database Drop, type must be set to <literal>drop</literal> in
1267 <function>ZOOM_package_send</function>.
1270 <table frame="top" id="zoom.database.drop.options">
1271 <title>Database Drop Options</title>
1273 <colspec colwidth="4*" colname="name"></colspec>
1274 <colspec colwidth="7*" colname="description"></colspec>
1275 <colspec colwidth="3*" colname="default"></colspec>
1278 <entry>Option</entry>
1279 <entry>Description</entry>
1280 <entry>Default</entry>
1285 <entry>databaseName</entry>
1286 <entry>Database from connection object</entry>
1287 <entry>Default</entry>
1294 <sect2 id="zoom.commit"><title>Commit Operation</title>
1296 For Commit, type must be set to <literal>commit</literal> in
1297 <function>ZOOM_package_send</function>.
1301 <sect2 id="zoom.extended.services.behavior">
1302 <title>Protocol behavior</title>
1304 All the extended services are Z39.50-only.
1308 The database create, drop and commit services are privately defined
1310 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1317 <sect1 id="zoom.options"><title>Options</title>
1319 Most &zoom; objects provide a way to specify options to change behavior.
1320 From an implementation point of view a set of options is just like
1321 an associative array / hash.
1324 ZOOM_options ZOOM_options_create (void);
1326 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1328 void ZOOM_options_destroy (ZOOM_options opt);
1331 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1333 void ZOOM_options_set (ZOOM_options opt, const char *name,
1337 typedef const char *(*ZOOM_options_callback)
1338 (void *handle, const char *name);
1340 ZOOM_options_callback
1341 ZOOM_options_set_callback (ZOOM_options opt,
1342 ZOOM_options_callback c,
1346 <sect1 id="zoom.events"><title>Events</title>
1348 If you're developing non-blocking applications, you have to deal
1352 int ZOOM_event (int no, ZOOM_connection *cs);
1355 The <function>ZOOM_event</function> executes pending events for
1356 a number of connections. Supply the number of connections in
1357 <literal>no</literal> and an array of connections in
1358 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1359 A pending event could be a sending a search, receiving a response,
1361 When an event has occurred for one of the connections, this function
1362 returns a positive integer <literal>n</literal> denoting that an event
1363 occurred for connection <literal>cs[n-1]</literal>.
1364 When no events are pending for the connections, a value of zero is
1366 To ensure that all outstanding requests are performed call this function
1367 repeatedly until zero is returned.
1370 If <function>ZOOM_event</function> returns and returns non-zero, the
1371 last event that occurred can be expected.
1374 int ZOOM_connection_last_event(ZOOM_connection cs);
1377 <function>ZOOM_connection_last_event</function> returns an event type
1378 (integer) for the last event.
1381 <table frame="top" id="zoom.event.ids">
1382 <title>ZOOM Event IDs</title>
1384 <colspec colwidth="4*" colname="name"></colspec>
1385 <colspec colwidth="7*" colname="description"></colspec>
1388 <entry>Event</entry>
1389 <entry>Description</entry>
1394 <entry>ZOOM_EVENT_NONE</entry>
1395 <entry>No event has occurred</entry>
1398 <entry>ZOOM_EVENT_CONNECT</entry>
1399 <entry>TCP/IP connect has initiated</entry>
1402 <entry>ZOOM_EVENT_SEND_DATA</entry>
1403 <entry>Data has been transmitted (sending)</entry>
1406 <entry>ZOOM_EVENT_RECV_DATA</entry>
1407 <entry>Data has been received)</entry>
1410 <entry>ZOOM_EVENT_TIMEOUT</entry>
1411 <entry>Timeout</entry>
1414 <entry>ZOOM_EVENT_UNKNOWN</entry>
1415 <entry>Unknown event</entry>
1418 <entry>ZOOM_EVENT_SEND_APDU</entry>
1419 <entry>An APDU has been transmitted (sending)</entry>
1422 <entry>ZOOM_EVENT_RECV_APDU</entry>
1423 <entry>An APDU has been received</entry>
1426 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1427 <entry>A result-set record has been received</entry>
1430 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1431 <entry>A search result been received</entry>
1439 <!-- Keep this comment at the end of the file
1444 sgml-minimize-attributes:nil
1445 sgml-always-quote-attributes:t
1448 sgml-parent-document: "yaz.xml"
1449 sgml-local-catalogs: nil
1450 sgml-namecase-general:t