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 <chapter id="zoom"><title>ZOOM</title>
25 &zoom; is an acronym for 'Z39.50 Object-Orientation Model' and is
26 an initiative started by Mike Taylor (Mike is from the UK, which
27 explains the peculiar name of the model). The goal of &zoom; is to
28 provide a common Z39.50 client API not bound to a particular
29 programming language or toolkit.
34 A recent addition to &yaz; is SRU support. You can now make
35 SRU ZOOM connections by specifying scheme <literal>http://</literal>
36 for the hostname for a connection. The dialect of SRU used is
37 specified by the value of the connection's <literal>sru</literal>
38 option, which may be SRU over HTTP GET (<literal>get</literal>),
39 SRU over HTTP POST (<literal>post</literal>) or SRW (SRU over
40 SOAP) (<literal>soap</literal>). Using the facility for embedding
41 options in target strings, a connection can be forced to use SRU
42 rather the SRW (the default) by prefixing the target string with
43 <literal>sru=get,</literal>, like this:
44 <literal>sru=get,http://sru.miketaylor.org.uk:80/sru.pl</literal>
49 The lack of a simple Z39.50 client API for &yaz; has become more
50 and more apparent over time. So when the first &zoom; specification
52 an implementation for &yaz; was quickly developed. For the first time, it is
53 now as easy (or easier!) to develop clients than servers with &yaz;. This
54 chapter describes the &zoom; C binding. Before going further, please
55 reconsider whether C is the right programming language for the job.
56 There are other language bindings available for &yaz;, and still
58 are in active development. See the
59 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
64 In order to fully understand this chapter you should read and
65 try the example programs <literal>zoomtst1.c</literal>,
66 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
71 The C language misses features found in object oriented languages
72 such as C++, Java, etc. For example, you'll have to manually,
73 destroy all objects you create, even though you may think of them as
74 temporary. Most objects has a <literal>_create</literal> - and a
75 <literal>_destroy</literal> variant.
76 All objects are in fact pointers to internal stuff, but you don't see
77 that because of typedefs. All destroy methods should gracefully ignore a
78 <literal>NULL</literal> pointer.
81 In each of the sections below you'll find a sub section called
82 protocol behavior, that describes how the API maps to the Z39.50
85 <sect1 id="zoom-connections"><title>Connections</title>
87 <para>The Connection object is a session with a target.
90 #include <yaz/zoom.h>
92 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
94 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
96 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
98 void ZOOM_connection_destroy(ZOOM_connection c);
101 Connection objects are created with either function
102 <function>ZOOM_connection_new</function> or
103 <function>ZOOM_connection_create</function>.
104 The former creates and automatically attempts to establish a network
105 connection with the target. The latter doesn't establish
106 a connection immediately, thus allowing you to specify options
107 before establishing network connection using the function
108 <function>ZOOM_connection_connect</function>.
109 If the port number, <literal>portnum</literal>, is zero, the
110 <literal>host</literal> is consulted for a port specification.
111 If no port is given, 210 is used. A colon denotes the beginning of
112 a port number in the host string. If the host string includes a
113 slash, the following part specifies a database for the connection.
116 You can prefix the host with a scheme followed by colon. The
117 default scheme is <literal>tcp</literal> (Z39.50 protocol).
118 The scheme <literal>http</literal> selects SRU over HTTP.
121 You can prefix the scheme-qualified host-string with one or more
123 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
124 sequences, each of which represents an option to be set into the
125 connection structure <emphasis>before</emphasis> the
126 protocol-level connection is forged and the initialization
127 handshake takes place. This facility can be used to provide
128 authentication credentials, as in host-strings such as:
129 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
132 Connection objects should be destroyed using the function
133 <function>ZOOM_connection_destroy</function>.
136 void ZOOM_connection_option_set(ZOOM_connection c,
137 const char *key, const char *val);
139 void ZOOM_connection_option_setl(ZOOM_connection c,
141 const char *val, int len);
143 const char *ZOOM_connection_option_get(ZOOM_connection c,
145 const char *ZOOM_connection_option_getl(ZOOM_connection c,
150 The functions <function>ZOOM_connection_option_set</function> and
151 <function>ZOOM_connection_option_setl</function> allows you to
152 set an option given by <parameter>key</parameter> to the value
153 <parameter>value</parameter> for the connection.
154 For <function>ZOOM_connection_option_set</function>, the
155 value is assumed to be a 0-terminated string. Function
156 <function>ZOOM_connection_option_setl</function> specifies a
157 value of a certain size (len).
160 Functions <function>ZOOM_connection_option_get</function> and
161 <function>ZOOM_connection_option_getl</function> returns
162 the value for an option given by <parameter>key</parameter>.
164 <table id="zoom-connection-options" frame="top">
165 <title>ZOOM Connection Options</title>
167 <colspec colwidth="4*" colname="name"></colspec>
168 <colspec colwidth="7*" colname="description"></colspec>
169 <colspec colwidth="3*" colname="default"></colspec>
172 <entry>Option</entry>
173 <entry>Description</entry>
174 <entry>Default</entry>
179 implementationName</entry><entry>Name of Your client
180 </entry><entry>none</entry></row>
182 user</entry><entry>Authentication user name
183 </entry><entry>none</entry></row>
185 group</entry><entry>Authentication group name
186 </entry><entry>none</entry></row>
188 password</entry><entry>Authentication password.
189 </entry><entry>none</entry></row>
191 host</entry><entry>Target host. This setting is "read-only".
192 It's automatically set internally when connecting to a target.
193 </entry><entry>none</entry></row>
195 proxy</entry><entry>Proxy host
196 </entry><entry>none</entry></row>
198 clientIP</entry><entry>Client IP. If set, is
199 encoded in the otherInfo area of a Z39.50 PDU with OID
200 1.2.840.10003.10.1000.81.3. Holds the original IP addreses
201 of a client. Is used of ZOOM is used in a gateway of some sort.
202 </entry><entry>none</entry></row>
204 async</entry><entry>If true (1) the connection operates in
205 asynchronous operation which means that all calls are non-blocking
207 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
208 </entry><entry>0</entry></row>
210 maximumRecordSize</entry><entry> Maximum size of single record.
211 </entry><entry>1 MB</entry></row>
213 preferredMessageSize</entry><entry> Maximum size of multiple records.
214 </entry><entry>1 MB</entry></row>
216 lang</entry><entry> Language for negotiation.
217 </entry><entry>none</entry></row>
219 charset</entry><entry> Character set for negotiation.
220 </entry><entry>none</entry></row>
222 serverImplementationId</entry><entry>
223 Implementation ID of server. (The old targetImplementationId
224 option is also supported for the benefit of old applications.)
225 </entry><entry>none</entry></row>
227 targetImplementationName</entry><entry>
228 Implementation Name of server. (The old
229 targetImplementationName option is also supported for the
230 benefit of old applications.)
231 </entry><entry>none</entry></row>
233 serverImplementationVersion</entry><entry>
234 Implementation Version of server. (the old
235 targetImplementationVersion option is also supported for the
236 benefit of old applications.)
237 </entry><entry>none</entry></row>
239 databaseName</entry><entry>One or more database names
240 separated by character plus (<literal>+</literal>), which to
241 be used by subsequent search requests on this Connection.
242 </entry><entry>Default</entry></row>
244 piggyback</entry><entry>True (1) if piggyback should be
245 used in searches; false (0) if not.
246 </entry><entry>1</entry></row>
248 smallSetUpperBound</entry><entry>If hits is less than or equal to this
249 value, then target will return all records using small element set name
250 </entry><entry>0</entry></row>
252 largeSetLowerBound</entry><entry>If hits is greater than this
253 value, the target will return no records.
254 </entry><entry>1</entry></row>
256 mediumSetPresentNumber</entry><entry>This value represents
257 the number of records to be returned as part of a search when when
258 hits is less than or equal to large set lower bound and if hits
259 is greater than small set upper bound.
260 </entry><entry>0</entry></row>
262 smallSetElementSetName</entry><entry>
263 The element set name to be used for small result sets.
264 </entry><entry>none</entry></row>
266 mediumSetElementSetName</entry><entry>
267 The element set name to be for medium-sized result sets.
268 </entry><entry>none</entry></row>
270 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
271 After a successful Init, these options may be interrogated to
272 discover whether the server claims to support the specified
274 </entry><entry>none</entry></row>
277 SRU transport type. Must be either <literal>soap</literal>,
278 <literal>get</literal> or <literal>post</literal>.
279 </entry><entry>soap</entry></row>
281 sru_version</entry><entry>
282 SRU/SRW version. Should be <literal>1.1</literal>, or
283 <literal>1.2</literal>. This is , prior to connect, the version
284 to offer (highest version). And following connect (in fact
285 first operation), holds the negotiated version with the server
286 (same or lower version).
287 </entry><entry>1.2</entry></row>
292 If either option <literal>lang</literal> or <literal>charset</literal>
294 <ulink url="&url.z39.50.charneg;">
295 Character Set and Language Negotiation</ulink> is in effect.
298 int ZOOM_connection_error(ZOOM_connection c, const char **cp,
299 const char **addinfo);
300 int ZOOM_connection_error_x(ZOOM_connection c, const char **cp,
301 const char **addinfo, const char **dset);
304 Function <function>ZOOM_connection_error</function> checks for
305 errors for the last operation(s) performed. The function returns
306 zero if no errors occurred; non-zero otherwise indicating the error.
307 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
308 holds messages for the error and additional-info if passed as
309 non-<literal>NULL</literal>. Function
310 <function>ZOOM_connection_error_x</function> is an extended version
311 of <function>ZOOM_connection_error</function> that is capable of
312 returning name of diagnostic set in <parameter>dset</parameter>.
314 <sect2 id="zoom-connection-z39.50">
315 <title>Z39.50 Protocol behavior</title>
317 The calls <function>ZOOM_connection_new</function> and
318 <function>ZOOM_connection_connect</function> establishes a TCP/IP
319 connection and sends an Initialize Request to the target if
320 possible. In addition, the calls waits for an Initialize Response
321 from the target and the result is inspected (OK or rejected).
324 If <literal>proxy</literal> is set then the client will establish
325 a TCP/IP connection with the peer as specified by the
326 <literal>proxy</literal> host and the hostname as part of the
327 connect calls will be set as part of the Initialize Request.
328 The proxy server will then "forward" the PDU's transparently
329 to the target behind the proxy.
332 For the authentication parameters, if option <literal>user</literal>
333 is set and both options <literal>group</literal> and
334 <literal>pass</literal> are unset, then Open style
335 authentication is used (Version 2/3) in which case the username
336 is usually followed by a slash, then by a password.
337 If either <literal>group</literal>
338 or <literal>pass</literal> is set then idPass authentication
339 (Version 3 only) is used. If none of the options are set, no
340 authentication parameters are set as part of the Initialize Request
344 When option <literal>async</literal> is 1, it really means that
345 all network operations are postponed (and queued) until the
346 function <literal>ZOOM_event</literal> is invoked. When doing so
347 it doesn't make sense to check for errors after
348 <literal>ZOOM_connection_new</literal> is called since that
349 operation "connecting - and init" is still incomplete and the
350 API cannot tell the outcome (yet).
353 <sect2 id="zoom.sru.init.behavior">
354 <title>SRU Protocol behavior</title>
356 The SRU protocol doesn't feature an Inititialize Request, so
357 the connection phase merely establishes a TCP/IP connection
358 with the SOAP service.
360 <para>Most of the ZOOM connection options do not
361 affect SRU and they are ignored. However, future versions
362 of &yaz; might honor <literal>implementationName</literal> and
363 put that as part of User-Agent header for HTTP requests.
366 The <literal>charset</literal> is used in the Content-Type header
371 <sect1 id="zoom.query"><title>Queries</title>
373 Query objects represents queries.
376 ZOOM_query ZOOM_query_create(void);
378 void ZOOM_query_destroy(ZOOM_query q);
380 int ZOOM_query_prefix(ZOOM_query q, const char *str);
382 int ZOOM_query_cql(ZOOM_query s, const char *str);
384 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
387 Create query objects using <function>ZOOM_query_create</function>
388 and destroy them by calling <function>ZOOM_query_destroy</function>.
389 RPN-queries can be specified in <link linkend="PQF">PQF</link>
390 notation by using the
391 function <function>ZOOM_query_prefix</function>.
392 The <function>ZOOM_query_cql</function> specifies a CQL
393 query to be sent to the server/target.
394 More query types will be added in future versions of &yaz;, such as
395 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
396 etc. In addition to a search, a sort criteria may be set. Function
397 <function>ZOOM_query_sortby</function> specifies a
398 sort criteria using the same string notation for sort as offered by
399 the <link linkend="sortspec">YAZ client</link>.
401 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
403 The query object is just an interface for the member Query
404 in the SearchRequest. The sortby-function is an interface to the
405 sortSequence member of the SortRequest.
409 <sect1 id="zoom.resultsets"><title>Result sets</title>
411 The result set object is a container for records returned from
415 ZOOM_resultset ZOOM_connection_search(ZOOM_connection, ZOOM_query q);
417 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
419 void ZOOM_resultset_destroy(ZOOM_resultset r);
422 Function <function>ZOOM_connection_search</function> creates
423 a result set given a connection and query.
424 Destroy a result set by calling
425 <function>ZOOM_resultset_destroy</function>.
426 Simple clients may using PQF only may use function
427 <function>ZOOM_connection_search_pqf</function> in which case
428 creating query objects is not necessary.
431 void ZOOM_resultset_option_set(ZOOM_resultset r,
432 const char *key, const char *val);
434 const char *ZOOM_resultset_option_get(ZOOM_resultset r, const char *key);
436 size_t ZOOM_resultset_size(ZOOM_resultset r);
439 Functions <function>ZOOM_resultset_options_set</function> and
440 <function>ZOOM_resultset_get</function> sets and gets an option
441 for a result set similar to <function>ZOOM_connection_option_get</function>
442 and <function>ZOOM_connection_option_set</function>.
445 The number of hits also called result-count is returned by
446 function <function>ZOOM_resultset_size</function>.
448 <table id="zoom.resultset.options"
449 frame="top"><title>ZOOM Result set Options</title>
451 <colspec colwidth="4*" colname="name"></colspec>
452 <colspec colwidth="7*" colname="description"></colspec>
453 <colspec colwidth="2*" colname="default"></colspec>
456 <entry>Option</entry>
457 <entry>Description</entry>
458 <entry>Default</entry>
463 start</entry><entry>Offset of first record to be
464 retrieved from target. First record has offset 0 unlike the
465 protocol specifications where first record has position 1.
466 This option affects ZOOM_resultset_search and
467 ZOOM_resultset_search_pqf and must be set before any of
468 these functions are invoked. If a range of
469 records must be fetched manually after search,
470 function ZOOM_resultset_records should be used.
471 </entry><entry>0</entry></row>
473 count</entry><entry>Number of records to be retrieved.
474 This option affects ZOOM_resultset_search and
475 ZOOM_resultset_search_pqf and must be set before any of
476 these functions are invoked.
477 </entry><entry>0</entry></row>
479 presentChunk</entry><entry>The number of records to be
480 requested from the server in each chunk (present request). The
481 value 0 means to request all the records in a single chunk.
482 (The old <literal>step</literal>
483 option is also supported for the benefit of old applications.)
484 </entry><entry>0</entry></row>
486 elementSetName</entry><entry>Element-Set name of records.
487 Most targets should honor element set name <literal>B</literal>
488 and <literal>F</literal> for brief and full respectively.
489 </entry><entry>none</entry></row>
491 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
492 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
493 </entry><entry>none</entry></row>
495 schema</entry><entry>Schema for retrieval, such as
496 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
497 </entry><entry>none</entry></row>
499 setname</entry><entry>Name of Result Set (Result Set ID).
500 If this option isn't set, the ZOOM module will automatically
501 allocate a result set name.
502 </entry><entry>default</entry></row>
504 rpnCharset</entry><entry>Character set for RPN terms.
505 If this is set, ZOOM C will assume that the ZOOM application is
506 running UTF-8. Terms in RPN queries are then converted to the
507 rpnCharset. If this is unset, ZOOM C will not assume any encoding
508 of RPN terms and no conversion is performed.
509 </entry><entry>none</entry></row>
514 For servers that support Search Info report, the following
515 options may be read using <function>ZOOM_resultset_get</function>.
516 This detailed information is read after a successful search has
520 This information is a list of of items, where each item is
521 information about a term or subquery. All items in the list
523 <literal>SearchResult.</literal><replaceable>no</replaceable>
524 where no presents the item number (0=first, 1=second).
525 Read <literal>searchresult.size</literal> to determine the
528 <table id="zoom.search.info.report.options"
529 frame="top"><title>Search Info Report Options</title>
531 <colspec colwidth="4*" colname="name"></colspec>
532 <colspec colwidth="7*" colname="description"></colspec>
535 <entry>Option</entry>
536 <entry>Description</entry>
541 <entry>searchresult.size</entry>
543 number of search result entries. This option is-nonexistant
544 if no entries are returned by the server.
548 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
549 <entry>sub query ID</entry>
552 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
553 <entry>result count for item (number of hits)</entry>
556 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
557 <entry>subquery term</entry>
561 searchresult.<replaceable>no</replaceable>.interpretation.term
563 <entry>interpretation term</entry>
567 searchresult.<replaceable>no</replaceable>.recommendation.term
569 <entry>recommendation term</entry>
574 <sect2 id="zoom.z3950.resultset.behavior">
575 <title>Z39.50 Protocol behavior</title>
577 The creation of a result set involves at least a SearchRequest
578 - SearchResponse protocol handshake. Following that, if a sort
579 criteria was specified as part of the query, a SortRequest -
580 SortResponse handshake takes place. Note that it is necessary to
581 perform sorting before any retrieval takes place, so no records will
582 be returned from the target as part of the SearchResponse because these
583 would be unsorted. Hence, piggyback is disabled when sort criteria
584 are set. Following Search - and a possible sort - Retrieval takes
585 place - as one or more Present Requests/Response pairs being
589 The API allows for two different modes for retrieval. A high level
590 mode which is somewhat more powerful and a low level one.
591 The low level is enabled when searching on a Connection object
592 for which the settings
593 <literal>smallSetUpperBound</literal>,
594 <literal>mediumSetPresentNumber</literal> and
595 <literal>largeSetLowerBound</literal> are set. The low level mode
596 thus allows you to precisely set how records are returned as part
597 of a search response as offered by the Z39.50 protocol.
598 Since the client may be retrieving records as part of the
599 search response, this mode doesn't work well if sorting is used.
602 The high-level mode allows you to fetch a range of records from
603 the result set with a given start offset. When you use this mode
604 the client will automatically use piggyback if that is possible
605 with the target and perform one or more present requests as needed.
606 Even if the target returns fewer records as part of a present response
607 because of a record size limit, etc. the client will repeat sending
608 present requests. As an example, if option <literal>start</literal>
609 is 0 (default) and <literal>count</literal> is 4, and
610 <literal>piggyback</literal> is 1 (default) and no sorting criteria
611 is specified, then the client will attempt to retrieve the 4
612 records as part the search response (using piggyback). On the other
613 hand, if either <literal>start</literal> is positive or if
614 a sorting criteria is set, or if <literal>piggyback</literal>
615 is 0, then the client will not perform piggyback but send Present
619 If either of the options <literal>mediumSetElementSetName</literal> and
620 <literal>smallSetElementSetName</literal> are unset, the value
621 of option <literal>elementSetName</literal> is used for piggyback
622 searches. This means that for the high-level mode you only have
623 to specify one elementSetName option rather than three.
626 <sect2 id="zoom.sru.resultset.behavior">
627 <title>SRU Protocol behavior</title>
629 Current version of &yaz; does not take advantage of a result set id
630 returned by the SRU server. Future versions might do, however.
631 Since, the ZOOM driver does not save result set IDs any
632 present (retrieval) is transformed to a SRU SearchRetrieveRequest
633 with same query but, possibly, different offsets.
636 Option <literal>schema</literal> specifies SRU schema
637 for retrieval. However, options <literal>elementSetName</literal> and
638 <literal>preferredRecordSyntax</literal> are ignored.
641 Options <literal>start</literal> and <literal>count</literal>
642 are supported by SRU.
643 The remaining options
644 <literal>piggyback</literal>,
645 <literal>smallSetUpperBound</literal>,
646 <literal>largeSetLowerBound</literal>,
647 <literal>mediumSetPresentNumber</literal>,
648 <literal>mediumSetElementSetName</literal>,
649 <literal>smallSetElementSetName</literal> are
653 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
654 If PQF is used, however, the PQF query is transferred anyway
655 using non-standard element <literal>pQuery</literal> in
656 SRU SearchRetrieveRequest.
659 Unfortunately, SRU does not define a database setting. Hence,
660 <literal>databaseName</literal> is unsupported and ignored.
661 However, the path part in host parameter for functions
662 <function>ZOOM_connecton_new</function> and
663 <function>ZOOM_connection_connect</function> acts as a
664 database (at least for the &yaz; SRU server).
668 <sect1 id="zoom.records"><title>Records</title>
670 A record object is a retrieval record on the client side -
671 created from result sets.
674 void ZOOM_resultset_records(ZOOM_resultset r,
676 size_t start, size_t count);
677 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
679 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
682 int ZOOM_record_error(ZOOM_record rec, const char **msg,
683 const char **addinfo, const char **diagset);
685 ZOOM_record ZOOM_record_clone(ZOOM_record rec);
687 void ZOOM_record_destroy(ZOOM_record rec);
690 References to temporary records are returned by functions
691 <function>ZOOM_resultset_records</function> or
692 <function>ZOOM_resultset_record</function>.
695 If a persistent reference to a record is desired
696 <function>ZOOM_record_clone</function> should be used.
697 It returns a record reference that should be destroyed
698 by a call to <function>ZOOM_record_destroy</function>.
701 A single record is returned by function
702 <function>ZOOM_resultset_record</function> that takes a
703 position as argument. First record has position zero.
704 If no record could be obtained <literal>NULL</literal> is returned.
707 Error information for a record can be checked with
708 <function>ZOOM_record_error</function> which returns non-zero
709 (error code) if record is in error, called <emphasis>Surrogate
710 Diagnostics</emphasis> in Z39.50.
713 Function <function>ZOOM_resultset_records</function> retrieves
714 a number of records from a result set. Parameter <literal>start</literal>
715 and <literal>count</literal> specifies the range of records to
716 be returned. Upon completion array
717 <literal>recs[0], ..recs[count-1]</literal>
718 holds record objects for the records. The array of records
719 <literal>recs</literal> should be allocated prior the call
720 <function>ZOOM_resultset_records</function>. Note that for those
721 records that couldn't be retrieved from the target
722 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
724 <para id="zoom.record.get">
725 In order to extract information about a single record,
726 <function>ZOOM_record_get</function> is provided. The
727 function returns a pointer to certain record information. The
728 nature (type) of the pointer depends on the parameter,
729 <parameter>type</parameter>.
732 The <parameter>type</parameter> is a string of the format:
735 <replaceable>form</replaceable>[;charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]][;format=<replaceable>v</replaceable>]
738 where <replaceable>form</replaceable> specifies the format of the
739 returned record, <replaceable>from</replaceable>
740 specifies the character set of the record in its original form
741 (as returned by the server), <replaceable>to</replaceable> specifies
742 the output (returned)
743 character set encoding.
744 If charset is not given, then no character set conversion takes place.
745 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
748 The format argument controls whether record data should be XML
749 pretty-printed (post process operation).
750 It is enabled only if format value <replaceable>v</replaceable> is
751 <literal>1</literal> and the record content is XML well-formed.
754 In addition, for certain types, the length
755 <literal>len</literal> passed will be set to the size in bytes of
756 the returned information.
759 The following are the supported values for <replaceable>form</replaceable>.
761 <varlistentry><term><literal>database</literal></term>
762 <listitem><para>Database of record is returned
763 as a C null-terminated string. Return type
764 <literal>const char *</literal>.
767 <varlistentry><term><literal>syntax</literal></term>
768 <listitem><para>The transfer syntax of the record is returned
769 as a C null-terminated string containing the symbolic name of
770 the record syntax, e.g. <literal>Usmarc</literal>. Return type
772 <literal>const char *</literal>.
775 <varlistentry><term><literal>schema</literal></term>
776 <listitem><para>The schema of the record is returned
777 as a C null-terminated string. Return type is
778 <literal>const char *</literal>.
781 <varlistentry><term><literal>render</literal></term>
782 <listitem><para>The record is returned in a display friendly
783 format. Upon completion buffer is returned
784 (type <literal>const char *</literal>) and length is stored in
785 <literal>*len</literal>.
788 <varlistentry><term><literal>raw</literal></term>
789 <listitem><para>The record is returned in the internal
790 YAZ specific format. For GRS-1, Explain, and others, the
791 raw data is returned as type
792 <literal>Z_External *</literal> which is just the type for
793 the member <literal>retrievalRecord</literal> in
794 type <literal>NamePlusRecord</literal>.
795 For SUTRS and octet aligned record (including all MARCs) the
796 octet buffer is returned and the length of the buffer.
799 <varlistentry><term><literal>xml</literal></term>
800 <listitem><para>The record is returned in XML if possible.
801 SRU and Z39.50 records with transfer syntax XML are
802 returned verbatim. MARC records are returned in
803 <ulink url="&url.marcxml;">
806 (converted from ISO2709 to MARCXML by YAZ).
807 OPAC records are also converted to XML and the
808 bibliographic record is converted to MARCXML (when possible).
809 GRS-1 records are not supported for this form.
810 Upon completion, the XML buffer is returned
811 (type <literal>const char *</literal>) and length is stored in
812 <literal>*len</literal>.
815 <varlistentry><term><literal>opac</literal></term>
816 <listitem><para>OPAC information for record is returned in XML
817 if an OPAC record is present at the position given. If no
818 OPAC record is present, a NULL pointer is returned.
821 <varlistentry><term><literal>txml</literal></term>
822 <listitem><para>The record is returned in TurboMARC if possible.
823 SRU and Z39.50 records with transfer syntax XML are
824 returned verbatim. MARC records are returned in
825 <link linkend="tools.turbomarc">
828 (converted from ISO2709 to TurboMARC by YAZ).
829 Upon completion, the XML buffer is returned
830 (type <literal>const char *</literal>) and length is stored in
831 <literal>*len</literal>.
838 <ulink url="&url.marc21;">MARC21</ulink>
840 <ulink url="&url.marc8;">MARC-8</ulink>
841 character set encoding.
842 An application that wishes to display in Latin-1 would use
844 render; charset=marc8,iso-8859-1
847 <sect2 id="zoom.z3950.record.behavior">
848 <title>Z39.50 Protocol behavior</title>
850 The functions <function>ZOOM_resultset_record</function> and
851 <function>ZOOM_resultset_records</function> inspects the client-side
852 record cache. Records not found in cache are fetched using
854 The functions may block (and perform network I/O) - even though option
855 <literal>async</literal> is 1, because they return records objects.
856 (and there's no way to return records objects without retrieving them!).
859 There is a trick, however, in the usage of function
860 <function>ZOOM_resultset_records</function> that allows for
861 delayed retrieval (and makes it non-blocking). By using
862 a null pointer for <parameter>recs</parameter> you're indicating
863 you're not interested in getting records objects
864 <emphasis>now</emphasis>.
867 <sect2 id="zoom.sru.record.behavior">
868 <title>SRU Protocol behavior</title>
870 The ZOOM driver for SRU treats records returned by a SRU server
871 as if they where Z39.50 records with transfer syntax XML and
872 no element set name or database name.
876 <sect1 id="zoom.scan"><title>Scan</title>
878 This section describes an interface for Scan. Scan is not an
879 official part of the ZOOM model yet. The result of a scan operation
880 is the <literal>ZOOM_scanset</literal> which is a set of terms
881 returned by a target.
885 The Scan interface is supported for both Z39.50 and SRU.
889 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
890 const char *startpqf);
892 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
895 size_t ZOOM_scanset_size(ZOOM_scanset scan);
897 const char *ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
898 size_t *occ, size_t *len);
900 const char *ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
901 size_t *occ, size_t *len);
903 void ZOOM_scanset_destroy(ZOOM_scanset scan);
905 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
908 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
912 The scan set is created by function
913 <function>ZOOM_connection_scan</function> which performs a scan
914 operation on the connection using the specified
915 <parameter>startpqf</parameter>.
916 If the operation was successful, the size of the scan set can be
917 retrieved by a call to <function>ZOOM_scanset_size</function>.
918 Like result sets, the items are numbered 0,..size-1.
919 To obtain information about a particular scan term, call function
920 <function>ZOOM_scanset_term</function>. This function takes
921 a scan set offset <literal>pos</literal> and returns a pointer
922 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
924 If present, the <literal>occ</literal> and <literal>len</literal>
925 are set to the number of occurrences and the length
926 of the actual term respectively.
927 <function>ZOOM_scanset_display_term</function> is similar to
928 <function>ZOOM_scanset_term</function> except that it returns
929 the <emphasis>display term</emphasis> rather than the raw term.
930 In a few cases, the term is different from display term. Always
931 use the display term for display and the raw term for subsequent
932 scan operations (to get more terms, next scan result, etc).
935 A scan set may be freed by a call to function
936 <function>ZOOM_scanset_destroy</function>.
937 Functions <function>ZOOM_scanset_option_get</function> and
938 <function>ZOOM_scanset_option_set</function> retrieves and sets
939 an option respectively.
943 The <parameter>startpqf</parameter> is a subset of PQF, namely
944 the Attributes+Term part. Multiple <literal>@attr</literal> can
945 be used. For example to scan in title (complete) phrases:
947 @attr 1=4 @attr 6=2 "science o"
952 The <function>ZOOM_connecton_scan1</function> is a newer and
953 more generic alternative to <function>ZOOM_connection_scan</function>
954 which allows to use both CQL and PQF for Scan.
957 <table frame="top" id="zoom.scanset.options">
958 <title>ZOOM Scan Set Options</title>
960 <colspec colwidth="4*" colname="name"></colspec>
961 <colspec colwidth="7*" colname="description"></colspec>
962 <colspec colwidth="2*" colname="default"></colspec>
965 <entry>Option</entry>
966 <entry>Description</entry>
967 <entry>Default</entry>
972 number</entry><entry>Number of Scan Terms requested in next scan.
973 After scan it holds the actual number of terms returned.
974 </entry><entry>20</entry></row>
976 position</entry><entry>Preferred Position of term in response
977 in next scan; actual position after completion of scan.
978 </entry><entry>1</entry></row>
980 stepSize</entry><entry>Step Size
981 </entry><entry>0</entry></row>
983 scanStatus</entry><entry>An integer indicating the Scan Status
985 </entry><entry>0</entry></row>
987 rpnCharset</entry><entry>Character set for RPN terms.
988 If this is set, ZOOM C will assume that the ZOOM application is
989 running UTF-8. Terms in RPN queries are then converted to the
990 rpnCharset. If this is unset, ZOOM C will not assume any encoding
991 of RPN terms and no conversion is performed.
992 </entry><entry>none</entry></row>
998 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
1000 ZOOM offers an interface to a subset of the Z39.50 extended services
1001 as well as a few privately defined ones:
1006 Z39.50 Item Order (ILL).
1007 See <xref linkend="zoom.item.order"/>.
1012 Record Update. This allows a client to insert, modify or delete
1014 See <xref linkend="zoom.record.update"/>.
1019 Database Create. This a non-standard feature. Allows a client
1020 to create a database.
1021 See <xref linkend="zoom.database.create"/>.
1026 Database Drop. This a non-standard feature. Allows a client
1027 to delete/drop a database.
1028 See <xref linkend="zoom.database.drop"/>.
1033 Commit operation. This a non-standard feature. Allows a client
1034 to commit operations.
1035 See <xref linkend="zoom.commit"/>.
1038 <!-- all the ILL PDU options should go here too -->
1041 To create an extended service operation a <literal>ZOOM_package</literal>
1042 must be created. The operation is a five step operation. The
1043 package is created, package is configured by means of options,
1044 the package is send, result is inspected (by means of options),
1045 the package is destroyed.
1048 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1049 ZOOM_options options);
1051 const char *ZOOM_package_option_get(ZOOM_package p,
1053 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1055 void ZOOM_package_send(ZOOM_package p, const char *type);
1057 void ZOOM_package_destroy(ZOOM_package p);
1060 The <function>ZOOM_connection_package</function> creates a
1061 package for the connection given using the options specified.
1064 Functions <function>ZOOM_package_option_get</function> and
1065 <function>ZOOM_package_option_set</function> gets and sets
1069 <function>ZOOM_package_send</function> sends
1070 the package the via connection specified in
1071 <function>ZOOM_connection_package</function>.
1072 The <parameter>type</parameter> specifies the actual extended service
1073 package type to be sent.
1076 <table frame="top" id="zoom.extendedservices.options">
1077 <title>Extended Service Common Options</title>
1079 <colspec colwidth="4*" colname="name"></colspec>
1080 <colspec colwidth="7*" colname="description"></colspec>
1081 <colspec colwidth="3*" colname="default"></colspec>
1084 <entry>Option</entry>
1085 <entry>Description</entry>
1086 <entry>Default</entry>
1091 <entry>package-name</entry>
1092 <entry>Extended Service Request package name. Must be specified
1093 as part of a request</entry>
1097 <entry>user-id</entry>
1098 <entry>User ID of Extended Service Package. Is a request option</entry>
1102 <entry>function</entry>
1104 Function of package - one of <literal>create</literal>,
1105 <literal>delete</literal>, <literal>modify</literal>. Is
1108 <entry><literal>create</literal></entry>
1111 <entry>waitAction</entry>
1113 Wait action for package. Possible values:
1114 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1115 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1117 <entry><literal>waitIfPossible</literal></entry>
1120 <entry>targetReference</entry>
1122 Target Reference. This is part of the response as returned
1123 by the server. Read it after a successful operation.
1125 <entry><literal>none</literal></entry>
1131 <sect2 id="zoom.item.order"><title>Item Order</title>
1133 For Item Order, type must be set to <literal>itemorder</literal> in
1134 <function>ZOOM_package_send</function>.
1137 <table frame="top" id="zoom.item.order.options">
1138 <title>Item Order Options</title>
1140 <colspec colwidth="4*" colname="name"></colspec>
1141 <colspec colwidth="7*" colname="description"></colspec>
1142 <colspec colwidth="3*" colname="default"></colspec>
1145 <entry>Option</entry>
1146 <entry>Description</entry>
1147 <entry>Default</entry>
1152 <entry>contact-name</entry>
1153 <entry>ILL contact name</entry>
1157 <entry>contact-phone</entry>
1158 <entry>ILL contact phone</entry>
1162 <entry>contact-email</entry>
1163 <entry>ILL contact email</entry>
1167 <entry>itemorder-item</entry>
1168 <entry>Position for item (record) requested. An integer</entry>
1177 <sect2 id="zoom.record.update"><title>Record Update</title>
1179 For Record Update, type must be set to <literal>update</literal> in
1180 <function>ZOOM_package_send</function>.
1183 <table frame="top" id="zoom.record.update.options">
1184 <title>Record Update Options</title>
1186 <colspec colwidth="4*" colname="name"></colspec>
1187 <colspec colwidth="7*" colname="description"></colspec>
1188 <colspec colwidth="3*" colname="default"></colspec>
1191 <entry>Option</entry>
1192 <entry>Description</entry>
1193 <entry>Default</entry>
1198 <entry>action</entry>
1200 The update action. One of
1201 <literal>specialUpdate</literal>,
1202 <literal>recordInsert</literal>,
1203 <literal>recordReplace</literal>,
1204 <literal>recordDelete</literal>,
1205 <literal>elementUpdate</literal>.
1207 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1210 <entry>recordIdOpaque</entry>
1211 <entry>Opaque Record ID</entry>
1215 <entry>recordIdNumber</entry>
1216 <entry>Record ID number</entry>
1220 <entry>record</entry>
1221 <entry>The record itself</entry>
1225 <entry>recordOpaque</entry>
1226 <entry>Specifies an opaque record which is
1227 encoded as an ASN.1 ANY type with the OID as tiven by option
1228 <literal>syntax</literal> (see below).
1229 Option <literal>recordOpaque</literal> is an alternative
1230 to record - and <literal>record</literal> option (above) is
1231 ignored if recordOpaque is set. This option is only available in
1232 YAZ 3.0.35 and later and is meant to facilitate Updates with
1238 <entry>syntax</entry>
1239 <entry>The record syntax (transfer syntax). Is a string that
1240 is a known record syntax.
1242 <entry>no syntax</entry>
1245 <entry>databaseName</entry>
1246 <entry>Database from connection object</entry>
1247 <entry>Default</entry>
1250 <entry>correlationInfo.note</entry>
1251 <entry>Correlation Info Note (string)</entry>
1255 <entry>correlationInfo.id</entry>
1256 <entry>Correlation Info ID (integer)</entry>
1260 <entry>elementSetName</entry>
1261 <entry>Element Set for Record</entry>
1265 <entry>updateVersion</entry>
1266 <entry>Record Update version which holds one of the values
1267 1, 2 or 3. Each version has a distinct OID:
1269 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1271 (second version) and
1272 1.2.840.10003.9.5.1.1
1273 (<ulink url="&url.z39.50.extupdate3;">third and
1274 newest version</ulink>).
1284 <sect2 id="zoom.database.create"><title>Database Create</title>
1286 For Database Create, type must be set to <literal>create</literal> in
1287 <function>ZOOM_package_send</function>.
1290 <table frame="top" id="zoom.database.create.options">
1291 <title>Database Create Options</title>
1293 <colspec colwidth="4*" colname="name"></colspec>
1294 <colspec colwidth="7*" colname="description"></colspec>
1295 <colspec colwidth="3*" colname="default"></colspec>
1298 <entry>Option</entry>
1299 <entry>Description</entry>
1300 <entry>Default</entry>
1305 <entry>databaseName</entry>
1306 <entry>Database from connection object</entry>
1307 <entry>Default</entry>
1314 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1316 For Database Drop, type must be set to <literal>drop</literal> in
1317 <function>ZOOM_package_send</function>.
1320 <table frame="top" id="zoom.database.drop.options">
1321 <title>Database Drop Options</title>
1323 <colspec colwidth="4*" colname="name"></colspec>
1324 <colspec colwidth="7*" colname="description"></colspec>
1325 <colspec colwidth="3*" colname="default"></colspec>
1328 <entry>Option</entry>
1329 <entry>Description</entry>
1330 <entry>Default</entry>
1335 <entry>databaseName</entry>
1336 <entry>Database from connection object</entry>
1337 <entry>Default</entry>
1344 <sect2 id="zoom.commit"><title>Commit Operation</title>
1346 For Commit, type must be set to <literal>commit</literal> in
1347 <function>ZOOM_package_send</function>.
1351 <sect2 id="zoom.extended.services.behavior">
1352 <title>Protocol behavior</title>
1354 All the extended services are Z39.50-only.
1358 The database create, drop and commit services are privately defined
1360 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1367 <sect1 id="zoom.options"><title>Options</title>
1369 Most &zoom; objects provide a way to specify options to change behavior.
1370 From an implementation point of view a set of options is just like
1371 an associative array / hash.
1374 ZOOM_options ZOOM_options_create(void);
1376 ZOOM_options ZOOM_options_create_with_parent(ZOOM_options parent);
1378 void ZOOM_options_destroy(ZOOM_options opt);
1381 const char *ZOOM_options_get(ZOOM_options opt, const char *name);
1383 void ZOOM_options_set(ZOOM_options opt, const char *name,
1387 typedef const char *(*ZOOM_options_callback)
1388 (void *handle, const char *name);
1390 ZOOM_options_callback
1391 ZOOM_options_set_callback(ZOOM_options opt,
1392 ZOOM_options_callback c,
1396 <sect1 id="zoom.events"><title>Events</title>
1398 If you're developing non-blocking applications, you have to deal
1402 int ZOOM_event(int no, ZOOM_connection *cs);
1405 The <function>ZOOM_event</function> executes pending events for
1406 a number of connections. Supply the number of connections in
1407 <literal>no</literal> and an array of connections in
1408 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1409 A pending event could be a sending a search, receiving a response,
1411 When an event has occurred for one of the connections, this function
1412 returns a positive integer <literal>n</literal> denoting that an event
1413 occurred for connection <literal>cs[n-1]</literal>.
1414 When no events are pending for the connections, a value of zero is
1416 To ensure that all outstanding requests are performed call this function
1417 repeatedly until zero is returned.
1420 If <function>ZOOM_event</function> returns and returns non-zero, the
1421 last event that occurred can be expected.
1424 int ZOOM_connection_last_event(ZOOM_connection cs);
1427 <function>ZOOM_connection_last_event</function> returns an event type
1428 (integer) for the last event.
1431 <table frame="top" id="zoom.event.ids">
1432 <title>ZOOM Event IDs</title>
1434 <colspec colwidth="4*" colname="name"></colspec>
1435 <colspec colwidth="7*" colname="description"></colspec>
1438 <entry>Event</entry>
1439 <entry>Description</entry>
1444 <entry>ZOOM_EVENT_NONE</entry>
1445 <entry>No event has occurred</entry>
1448 <entry>ZOOM_EVENT_CONNECT</entry>
1449 <entry>TCP/IP connect has initiated</entry>
1452 <entry>ZOOM_EVENT_SEND_DATA</entry>
1453 <entry>Data has been transmitted (sending)</entry>
1456 <entry>ZOOM_EVENT_RECV_DATA</entry>
1457 <entry>Data has been received)</entry>
1460 <entry>ZOOM_EVENT_TIMEOUT</entry>
1461 <entry>Timeout</entry>
1464 <entry>ZOOM_EVENT_UNKNOWN</entry>
1465 <entry>Unknown event</entry>
1468 <entry>ZOOM_EVENT_SEND_APDU</entry>
1469 <entry>An APDU has been transmitted (sending)</entry>
1472 <entry>ZOOM_EVENT_RECV_APDU</entry>
1473 <entry>An APDU has been received</entry>
1476 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1477 <entry>A result-set record has been received</entry>
1480 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1481 <entry>A search result been received</entry>
1489 <!-- Keep this comment at the end of the file
1494 sgml-minimize-attributes:nil
1495 sgml-always-quote-attributes:t
1498 sgml-parent-document: "yaz.xml"
1499 sgml-local-catalogs: nil
1500 sgml-namecase-general:t