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. If set, the logical host
196 is encoded in the otherInfo area of the Z39.50 Init PDU
197 with OID 1.2.840.10003.10.1000.81.1.
198 </entry><entry>none</entry></row>
200 clientIP</entry><entry>Client IP. If set, is
201 encoded in the otherInfo area of a Z39.50 PDU with OID
202 1.2.840.10003.10.1000.81.3. Holds the original IP addreses
203 of a client. Is used of ZOOM is used in a gateway of some sort.
204 </entry><entry>none</entry></row>
206 async</entry><entry>If true (1) the connection operates in
207 asynchronous operation which means that all calls are non-blocking
209 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
210 </entry><entry>0</entry></row>
212 maximumRecordSize</entry><entry> Maximum size of single record.
213 </entry><entry>1 MB</entry></row>
215 preferredMessageSize</entry><entry> Maximum size of multiple records.
216 </entry><entry>1 MB</entry></row>
218 lang</entry><entry> Language for negotiation.
219 </entry><entry>none</entry></row>
221 charset</entry><entry> Character set for negotiation.
222 </entry><entry>none</entry></row>
224 serverImplementationId</entry><entry>
225 Implementation ID of server. (The old targetImplementationId
226 option is also supported for the benefit of old applications.)
227 </entry><entry>none</entry></row>
229 targetImplementationName</entry><entry>
230 Implementation Name of server. (The old
231 targetImplementationName option is also supported for the
232 benefit of old applications.)
233 </entry><entry>none</entry></row>
235 serverImplementationVersion</entry><entry>
236 Implementation Version of server. (the old
237 targetImplementationVersion option is also supported for the
238 benefit of old applications.)
239 </entry><entry>none</entry></row>
241 databaseName</entry><entry>One or more database names
242 separated by character plus (<literal>+</literal>), which to
243 be used by subsequent search requests on this Connection.
244 </entry><entry>Default</entry></row>
246 piggyback</entry><entry>True (1) if piggyback should be
247 used in searches; false (0) if not.
248 </entry><entry>1</entry></row>
250 smallSetUpperBound</entry><entry>If hits is less than or equal to this
251 value, then target will return all records using small element set name
252 </entry><entry>0</entry></row>
254 largeSetLowerBound</entry><entry>If hits is greater than this
255 value, the target will return no records.
256 </entry><entry>1</entry></row>
258 mediumSetPresentNumber</entry><entry>This value represents
259 the number of records to be returned as part of a search when when
260 hits is less than or equal to large set lower bound and if hits
261 is greater than small set upper bound.
262 </entry><entry>0</entry></row>
264 smallSetElementSetName</entry><entry>
265 The element set name to be used for small result sets.
266 </entry><entry>none</entry></row>
268 mediumSetElementSetName</entry><entry>
269 The element set name to be for medium-sized result sets.
270 </entry><entry>none</entry></row>
272 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
273 After a successful Init, these options may be interrogated to
274 discover whether the server claims to support the specified
276 </entry><entry>none</entry></row>
279 SRU transport type. Must be either <literal>soap</literal>,
280 <literal>get</literal> or <literal>post</literal>.
281 </entry><entry>soap</entry></row>
283 sru_version</entry><entry>
284 SRU/SRW version. Should be <literal>1.1</literal>, or
285 <literal>1.2</literal>. This is , prior to connect, the version
286 to offer (highest version). And following connect (in fact
287 first operation), holds the negotiated version with the server
288 (same or lower version).
289 </entry><entry>1.2</entry></row>
291 facets</entry><entry>
292 A FacetList is comma-separated list of facet, which is defined as <literal>AttributeList</literal>
293 and a optional FacetTerm (a Term and a frequency). On request the terms is missing.
294 On response the the list contains the terms that the target could collect.
295 </entry><entry>none</entry></row>
300 If either option <literal>lang</literal> or <literal>charset</literal>
302 <ulink url="&url.z39.50.charneg;">
303 Character Set and Language Negotiation</ulink> is in effect.
306 int ZOOM_connection_error(ZOOM_connection c, const char **cp,
307 const char **addinfo);
308 int ZOOM_connection_error_x(ZOOM_connection c, const char **cp,
309 const char **addinfo, const char **dset);
312 Function <function>ZOOM_connection_error</function> checks for
313 errors for the last operation(s) performed. The function returns
314 zero if no errors occurred; non-zero otherwise indicating the error.
315 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
316 holds messages for the error and additional-info if passed as
317 non-<literal>NULL</literal>. Function
318 <function>ZOOM_connection_error_x</function> is an extended version
319 of <function>ZOOM_connection_error</function> that is capable of
320 returning name of diagnostic set in <parameter>dset</parameter>.
322 <sect2 id="zoom-connection-z39.50">
323 <title>Z39.50 Protocol behavior</title>
325 The calls <function>ZOOM_connection_new</function> and
326 <function>ZOOM_connection_connect</function> establishes a TCP/IP
327 connection and sends an Initialize Request to the target if
328 possible. In addition, the calls waits for an Initialize Response
329 from the target and the result is inspected (OK or rejected).
332 If <literal>proxy</literal> is set then the client will establish
333 a TCP/IP connection with the peer as specified by the
334 <literal>proxy</literal> host and the hostname as part of the
335 connect calls will be set as part of the Initialize Request.
336 The proxy server will then "forward" the PDU's transparently
337 to the target behind the proxy.
340 For the authentication parameters, if option <literal>user</literal>
341 is set and both options <literal>group</literal> and
342 <literal>pass</literal> are unset, then Open style
343 authentication is used (Version 2/3) in which case the username
344 is usually followed by a slash, then by a password.
345 If either <literal>group</literal>
346 or <literal>pass</literal> is set then idPass authentication
347 (Version 3 only) is used. If none of the options are set, no
348 authentication parameters are set as part of the Initialize Request
352 When option <literal>async</literal> is 1, it really means that
353 all network operations are postponed (and queued) until the
354 function <literal>ZOOM_event</literal> is invoked. When doing so
355 it doesn't make sense to check for errors after
356 <literal>ZOOM_connection_new</literal> is called since that
357 operation "connecting - and init" is still incomplete and the
358 API cannot tell the outcome (yet).
361 <sect2 id="zoom.sru.init.behavior">
362 <title>SRU Protocol behavior</title>
364 The SRU protocol doesn't feature an Inititialize Request, so
365 the connection phase merely establishes a TCP/IP connection
366 with the SOAP service.
368 <para>Most of the ZOOM connection options do not
369 affect SRU and they are ignored. However, future versions
370 of &yaz; might honor <literal>implementationName</literal> and
371 put that as part of User-Agent header for HTTP requests.
374 The <literal>charset</literal> is used in the Content-Type header
379 <sect1 id="zoom.query"><title>Queries</title>
381 Query objects represents queries.
384 ZOOM_query ZOOM_query_create(void);
386 void ZOOM_query_destroy(ZOOM_query q);
388 int ZOOM_query_prefix(ZOOM_query q, const char *str);
390 int ZOOM_query_cql(ZOOM_query s, const char *str);
392 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
395 Create query objects using <function>ZOOM_query_create</function>
396 and destroy them by calling <function>ZOOM_query_destroy</function>.
397 RPN-queries can be specified in <link linkend="PQF">PQF</link>
398 notation by using the
399 function <function>ZOOM_query_prefix</function>.
400 The <function>ZOOM_query_cql</function> specifies a CQL
401 query to be sent to the server/target.
402 More query types will be added in future versions of &yaz;, such as
403 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
404 etc. In addition to a search, a sort criteria may be set. Function
405 <function>ZOOM_query_sortby</function> specifies a
406 sort criteria using the same string notation for sort as offered by
407 the <link linkend="sortspec">YAZ client</link>.
409 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
411 The query object is just an interface for the member Query
412 in the SearchRequest. The sortby-function is an interface to the
413 sortSequence member of the SortRequest.
417 <sect1 id="zoom.resultsets"><title>Result sets</title>
419 The result set object is a container for records returned from
423 ZOOM_resultset ZOOM_connection_search(ZOOM_connection, ZOOM_query q);
425 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
427 void ZOOM_resultset_destroy(ZOOM_resultset r);
430 Function <function>ZOOM_connection_search</function> creates
431 a result set given a connection and query.
432 Destroy a result set by calling
433 <function>ZOOM_resultset_destroy</function>.
434 Simple clients may using PQF only may use function
435 <function>ZOOM_connection_search_pqf</function> in which case
436 creating query objects is not necessary.
439 void ZOOM_resultset_option_set(ZOOM_resultset r,
440 const char *key, const char *val);
442 const char *ZOOM_resultset_option_get(ZOOM_resultset r, const char *key);
444 size_t ZOOM_resultset_size(ZOOM_resultset r);
447 Functions <function>ZOOM_resultset_options_set</function> and
448 <function>ZOOM_resultset_get</function> sets and gets an option
449 for a result set similar to <function>ZOOM_connection_option_get</function>
450 and <function>ZOOM_connection_option_set</function>.
453 The number of hits also called result-count is returned by
454 function <function>ZOOM_resultset_size</function>.
456 <table id="zoom.resultset.options"
457 frame="top"><title>ZOOM Result set Options</title>
459 <colspec colwidth="4*" colname="name"></colspec>
460 <colspec colwidth="7*" colname="description"></colspec>
461 <colspec colwidth="2*" colname="default"></colspec>
464 <entry>Option</entry>
465 <entry>Description</entry>
466 <entry>Default</entry>
471 start</entry><entry>Offset of first record to be
472 retrieved from target. First record has offset 0 unlike the
473 protocol specifications where first record has position 1.
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. If a range of
477 records must be fetched manually after search,
478 function ZOOM_resultset_records should be used.
479 </entry><entry>0</entry></row>
481 count</entry><entry>Number of records to be retrieved.
482 This option affects ZOOM_resultset_search and
483 ZOOM_resultset_search_pqf and must be set before any of
484 these functions are invoked.
485 </entry><entry>0</entry></row>
487 presentChunk</entry><entry>The number of records to be
488 requested from the server in each chunk (present request). The
489 value 0 means to request all the records in a single chunk.
490 (The old <literal>step</literal>
491 option is also supported for the benefit of old applications.)
492 </entry><entry>0</entry></row>
494 elementSetName</entry><entry>Element-Set name of records.
495 Most targets should honor element set name <literal>B</literal>
496 and <literal>F</literal> for brief and full respectively.
497 </entry><entry>none</entry></row>
499 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
500 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
501 </entry><entry>none</entry></row>
503 schema</entry><entry>Schema for retrieval, such as
504 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
505 </entry><entry>none</entry></row>
507 setname</entry><entry>Name of Result Set (Result Set ID).
508 If this option isn't set, the ZOOM module will automatically
509 allocate a result set name.
510 </entry><entry>default</entry></row>
512 rpnCharset</entry><entry>Character set for RPN terms.
513 If this is set, ZOOM C will assume that the ZOOM application is
514 running UTF-8. Terms in RPN queries are then converted to the
515 rpnCharset. If this is unset, ZOOM C will not assume any encoding
516 of RPN terms and no conversion is performed.
517 </entry><entry>none</entry></row>
522 For servers that support Search Info report, the following
523 options may be read using <function>ZOOM_resultset_get</function>.
524 This detailed information is read after a successful search has
528 This information is a list of of items, where each item is
529 information about a term or subquery. All items in the list
531 <literal>SearchResult.</literal><replaceable>no</replaceable>
532 where no presents the item number (0=first, 1=second).
533 Read <literal>searchresult.size</literal> to determine the
536 <table id="zoom.search.info.report.options"
537 frame="top"><title>Search Info Report Options</title>
539 <colspec colwidth="4*" colname="name"></colspec>
540 <colspec colwidth="7*" colname="description"></colspec>
543 <entry>Option</entry>
544 <entry>Description</entry>
549 <entry>searchresult.size</entry>
551 number of search result entries. This option is-nonexistant
552 if no entries are returned by the server.
556 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
557 <entry>sub query ID</entry>
560 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
561 <entry>result count for item (number of hits)</entry>
564 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
565 <entry>subquery term</entry>
569 searchresult.<replaceable>no</replaceable>.interpretation.term
571 <entry>interpretation term</entry>
575 searchresult.<replaceable>no</replaceable>.recommendation.term
577 <entry>recommendation term</entry>
582 <sect2 id="zoom.z3950.resultset.behavior">
583 <title>Z39.50 Protocol behavior</title>
585 The creation of a result set involves at least a SearchRequest
586 - SearchResponse protocol handshake. Following that, if a sort
587 criteria was specified as part of the query, a SortRequest -
588 SortResponse handshake takes place. Note that it is necessary to
589 perform sorting before any retrieval takes place, so no records will
590 be returned from the target as part of the SearchResponse because these
591 would be unsorted. Hence, piggyback is disabled when sort criteria
592 are set. Following Search - and a possible sort - Retrieval takes
593 place - as one or more Present Requests/Response pairs being
597 The API allows for two different modes for retrieval. A high level
598 mode which is somewhat more powerful and a low level one.
599 The low level is enabled when searching on a Connection object
600 for which the settings
601 <literal>smallSetUpperBound</literal>,
602 <literal>mediumSetPresentNumber</literal> and
603 <literal>largeSetLowerBound</literal> are set. The low level mode
604 thus allows you to precisely set how records are returned as part
605 of a search response as offered by the Z39.50 protocol.
606 Since the client may be retrieving records as part of the
607 search response, this mode doesn't work well if sorting is used.
610 The high-level mode allows you to fetch a range of records from
611 the result set with a given start offset. When you use this mode
612 the client will automatically use piggyback if that is possible
613 with the target and perform one or more present requests as needed.
614 Even if the target returns fewer records as part of a present response
615 because of a record size limit, etc. the client will repeat sending
616 present requests. As an example, if option <literal>start</literal>
617 is 0 (default) and <literal>count</literal> is 4, and
618 <literal>piggyback</literal> is 1 (default) and no sorting criteria
619 is specified, then the client will attempt to retrieve the 4
620 records as part the search response (using piggyback). On the other
621 hand, if either <literal>start</literal> is positive or if
622 a sorting criteria is set, or if <literal>piggyback</literal>
623 is 0, then the client will not perform piggyback but send Present
627 If either of the options <literal>mediumSetElementSetName</literal> and
628 <literal>smallSetElementSetName</literal> are unset, the value
629 of option <literal>elementSetName</literal> is used for piggyback
630 searches. This means that for the high-level mode you only have
631 to specify one elementSetName option rather than three.
634 <sect2 id="zoom.sru.resultset.behavior">
635 <title>SRU Protocol behavior</title>
637 Current version of &yaz; does not take advantage of a result set id
638 returned by the SRU server. Future versions might do, however.
639 Since, the ZOOM driver does not save result set IDs any
640 present (retrieval) is transformed to a SRU SearchRetrieveRequest
641 with same query but, possibly, different offsets.
644 Option <literal>schema</literal> specifies SRU schema
645 for retrieval. However, options <literal>elementSetName</literal> and
646 <literal>preferredRecordSyntax</literal> are ignored.
649 Options <literal>start</literal> and <literal>count</literal>
650 are supported by SRU.
651 The remaining options
652 <literal>piggyback</literal>,
653 <literal>smallSetUpperBound</literal>,
654 <literal>largeSetLowerBound</literal>,
655 <literal>mediumSetPresentNumber</literal>,
656 <literal>mediumSetElementSetName</literal>,
657 <literal>smallSetElementSetName</literal> are
661 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
662 If PQF is used, however, the PQF query is transferred anyway
663 using non-standard element <literal>pQuery</literal> in
664 SRU SearchRetrieveRequest.
667 Unfortunately, SRU does not define a database setting. Hence,
668 <literal>databaseName</literal> is unsupported and ignored.
669 However, the path part in host parameter for functions
670 <function>ZOOM_connecton_new</function> and
671 <function>ZOOM_connection_connect</function> acts as a
672 database (at least for the &yaz; SRU server).
676 <sect1 id="zoom.records"><title>Records</title>
678 A record object is a retrieval record on the client side -
679 created from result sets.
682 void ZOOM_resultset_records(ZOOM_resultset r,
684 size_t start, size_t count);
685 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
687 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
690 int ZOOM_record_error(ZOOM_record rec, const char **msg,
691 const char **addinfo, const char **diagset);
693 ZOOM_record ZOOM_record_clone(ZOOM_record rec);
695 void ZOOM_record_destroy(ZOOM_record rec);
698 References to temporary records are returned by functions
699 <function>ZOOM_resultset_records</function> or
700 <function>ZOOM_resultset_record</function>.
703 If a persistent reference to a record is desired
704 <function>ZOOM_record_clone</function> should be used.
705 It returns a record reference that should be destroyed
706 by a call to <function>ZOOM_record_destroy</function>.
709 A single record is returned by function
710 <function>ZOOM_resultset_record</function> that takes a
711 position as argument. First record has position zero.
712 If no record could be obtained <literal>NULL</literal> is returned.
715 Error information for a record can be checked with
716 <function>ZOOM_record_error</function> which returns non-zero
717 (error code) if record is in error, called <emphasis>Surrogate
718 Diagnostics</emphasis> in Z39.50.
721 Function <function>ZOOM_resultset_records</function> retrieves
722 a number of records from a result set. Parameter <literal>start</literal>
723 and <literal>count</literal> specifies the range of records to
724 be returned. Upon completion array
725 <literal>recs[0], ..recs[count-1]</literal>
726 holds record objects for the records. The array of records
727 <literal>recs</literal> should be allocated prior the call
728 <function>ZOOM_resultset_records</function>. Note that for those
729 records that couldn't be retrieved from the target
730 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
732 <para id="zoom.record.get">
733 In order to extract information about a single record,
734 <function>ZOOM_record_get</function> is provided. The
735 function returns a pointer to certain record information. The
736 nature (type) of the pointer depends on the parameter,
737 <parameter>type</parameter>.
740 The <parameter>type</parameter> is a string of the format:
743 <replaceable>form</replaceable>[;charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]][;format=<replaceable>v</replaceable>]
746 where <replaceable>form</replaceable> specifies the format of the
747 returned record, <replaceable>from</replaceable>
748 specifies the character set of the record in its original form
749 (as returned by the server), <replaceable>to</replaceable> specifies
750 the output (returned)
751 character set encoding.
752 If charset is not given, then no character set conversion takes place.
753 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
756 The format argument controls whether record data should be XML
757 pretty-printed (post process operation).
758 It is enabled only if format value <replaceable>v</replaceable> is
759 <literal>1</literal> and the record content is XML well-formed.
762 In addition, for certain types, the length
763 <literal>len</literal> passed will be set to the size in bytes of
764 the returned information.
767 The following are the supported values for <replaceable>form</replaceable>.
769 <varlistentry><term><literal>database</literal></term>
770 <listitem><para>Database of record is returned
771 as a C null-terminated string. Return type
772 <literal>const char *</literal>.
775 <varlistentry><term><literal>syntax</literal></term>
776 <listitem><para>The transfer syntax of the record is returned
777 as a C null-terminated string containing the symbolic name of
778 the record syntax, e.g. <literal>Usmarc</literal>. Return type
780 <literal>const char *</literal>.
783 <varlistentry><term><literal>schema</literal></term>
784 <listitem><para>The schema of the record is returned
785 as a C null-terminated string. Return type is
786 <literal>const char *</literal>.
789 <varlistentry><term><literal>render</literal></term>
790 <listitem><para>The record is returned in a display friendly
791 format. Upon completion buffer is returned
792 (type <literal>const char *</literal>) and length is stored in
793 <literal>*len</literal>.
796 <varlistentry><term><literal>raw</literal></term>
797 <listitem><para>The record is returned in the internal
798 YAZ specific format. For GRS-1, Explain, and others, the
799 raw data is returned as type
800 <literal>Z_External *</literal> which is just the type for
801 the member <literal>retrievalRecord</literal> in
802 type <literal>NamePlusRecord</literal>.
803 For SUTRS and octet aligned record (including all MARCs) the
804 octet buffer is returned and the length of the buffer.
807 <varlistentry><term><literal>xml</literal></term>
808 <listitem><para>The record is returned in XML if possible.
809 SRU and Z39.50 records with transfer syntax XML are
810 returned verbatim. MARC records are returned in
811 <ulink url="&url.marcxml;">
814 (converted from ISO2709 to MARCXML by YAZ).
815 OPAC records are also converted to XML and the
816 bibliographic record is converted to MARCXML (when possible).
817 GRS-1 records are not supported for this form.
818 Upon completion, the XML buffer is returned
819 (type <literal>const char *</literal>) and length is stored in
820 <literal>*len</literal>.
823 <varlistentry><term><literal>opac</literal></term>
824 <listitem><para>OPAC information for record is returned in XML
825 if an OPAC record is present at the position given. If no
826 OPAC record is present, a NULL pointer is returned.
829 <varlistentry><term><literal>txml</literal></term>
830 <listitem><para>The record is returned in TurboMARC if possible.
831 SRU and Z39.50 records with transfer syntax XML are
832 returned verbatim. MARC records are returned in
833 <link linkend="tools.turbomarc">
836 (converted from ISO2709 to TurboMARC by YAZ).
837 Upon completion, the XML buffer is returned
838 (type <literal>const char *</literal>) and length is stored in
839 <literal>*len</literal>.
846 <ulink url="&url.marc21;">MARC21</ulink>
848 <ulink url="&url.marc8;">MARC-8</ulink>
849 character set encoding.
850 An application that wishes to display in Latin-1 would use
852 render; charset=marc8,iso-8859-1
855 <sect2 id="zoom.z3950.record.behavior">
856 <title>Z39.50 Protocol behavior</title>
858 The functions <function>ZOOM_resultset_record</function> and
859 <function>ZOOM_resultset_records</function> inspects the client-side
860 record cache. Records not found in cache are fetched using
862 The functions may block (and perform network I/O) - even though option
863 <literal>async</literal> is 1, because they return records objects.
864 (and there's no way to return records objects without retrieving them!).
867 There is a trick, however, in the usage of function
868 <function>ZOOM_resultset_records</function> that allows for
869 delayed retrieval (and makes it non-blocking). By using
870 a null pointer for <parameter>recs</parameter> you're indicating
871 you're not interested in getting records objects
872 <emphasis>now</emphasis>.
875 <sect2 id="zoom.sru.record.behavior">
876 <title>SRU Protocol behavior</title>
878 The ZOOM driver for SRU treats records returned by a SRU server
879 as if they where Z39.50 records with transfer syntax XML and
880 no element set name or database name.
884 <sect1 id="zoom.scan"><title>Scan</title>
886 This section describes an interface for Scan. Scan is not an
887 official part of the ZOOM model yet. The result of a scan operation
888 is the <literal>ZOOM_scanset</literal> which is a set of terms
889 returned by a target.
893 The Scan interface is supported for both Z39.50 and SRU.
897 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
898 const char *startpqf);
900 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
903 size_t ZOOM_scanset_size(ZOOM_scanset scan);
905 const char *ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
906 size_t *occ, size_t *len);
908 const char *ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
909 size_t *occ, size_t *len);
911 void ZOOM_scanset_destroy(ZOOM_scanset scan);
913 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
916 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
920 The scan set is created by function
921 <function>ZOOM_connection_scan</function> which performs a scan
922 operation on the connection using the specified
923 <parameter>startpqf</parameter>.
924 If the operation was successful, the size of the scan set can be
925 retrieved by a call to <function>ZOOM_scanset_size</function>.
926 Like result sets, the items are numbered 0,..size-1.
927 To obtain information about a particular scan term, call function
928 <function>ZOOM_scanset_term</function>. This function takes
929 a scan set offset <literal>pos</literal> and returns a pointer
930 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
932 If present, the <literal>occ</literal> and <literal>len</literal>
933 are set to the number of occurrences and the length
934 of the actual term respectively.
935 <function>ZOOM_scanset_display_term</function> is similar to
936 <function>ZOOM_scanset_term</function> except that it returns
937 the <emphasis>display term</emphasis> rather than the raw term.
938 In a few cases, the term is different from display term. Always
939 use the display term for display and the raw term for subsequent
940 scan operations (to get more terms, next scan result, etc).
943 A scan set may be freed by a call to function
944 <function>ZOOM_scanset_destroy</function>.
945 Functions <function>ZOOM_scanset_option_get</function> and
946 <function>ZOOM_scanset_option_set</function> retrieves and sets
947 an option respectively.
951 The <parameter>startpqf</parameter> is a subset of PQF, namely
952 the Attributes+Term part. Multiple <literal>@attr</literal> can
953 be used. For example to scan in title (complete) phrases:
955 @attr 1=4 @attr 6=2 "science o"
960 The <function>ZOOM_connecton_scan1</function> is a newer and
961 more generic alternative to <function>ZOOM_connection_scan</function>
962 which allows to use both CQL and PQF for Scan.
965 <table frame="top" id="zoom.scanset.options">
966 <title>ZOOM Scan Set Options</title>
968 <colspec colwidth="4*" colname="name"></colspec>
969 <colspec colwidth="7*" colname="description"></colspec>
970 <colspec colwidth="2*" colname="default"></colspec>
973 <entry>Option</entry>
974 <entry>Description</entry>
975 <entry>Default</entry>
980 number</entry><entry>Number of Scan Terms requested in next scan.
981 After scan it holds the actual number of terms returned.
982 </entry><entry>20</entry></row>
984 position</entry><entry>Preferred Position of term in response
985 in next scan; actual position after completion of scan.
986 </entry><entry>1</entry></row>
988 stepSize</entry><entry>Step Size
989 </entry><entry>0</entry></row>
991 scanStatus</entry><entry>An integer indicating the Scan Status
993 </entry><entry>0</entry></row>
995 rpnCharset</entry><entry>Character set for RPN terms.
996 If this is set, ZOOM C will assume that the ZOOM application is
997 running UTF-8. Terms in RPN queries are then converted to the
998 rpnCharset. If this is unset, ZOOM C will not assume any encoding
999 of RPN terms and no conversion is performed.
1000 </entry><entry>none</entry></row>
1006 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
1008 ZOOM offers an interface to a subset of the Z39.50 extended services
1009 as well as a few privately defined ones:
1014 Z39.50 Item Order (ILL).
1015 See <xref linkend="zoom.item.order"/>.
1020 Record Update. This allows a client to insert, modify or delete
1022 See <xref linkend="zoom.record.update"/>.
1027 Database Create. This a non-standard feature. Allows a client
1028 to create a database.
1029 See <xref linkend="zoom.database.create"/>.
1034 Database Drop. This a non-standard feature. Allows a client
1035 to delete/drop a database.
1036 See <xref linkend="zoom.database.drop"/>.
1041 Commit operation. This a non-standard feature. Allows a client
1042 to commit operations.
1043 See <xref linkend="zoom.commit"/>.
1046 <!-- all the ILL PDU options should go here too -->
1049 To create an extended service operation a <literal>ZOOM_package</literal>
1050 must be created. The operation is a five step operation. The
1051 package is created, package is configured by means of options,
1052 the package is send, result is inspected (by means of options),
1053 the package is destroyed.
1056 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1057 ZOOM_options options);
1059 const char *ZOOM_package_option_get(ZOOM_package p,
1061 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1063 void ZOOM_package_send(ZOOM_package p, const char *type);
1065 void ZOOM_package_destroy(ZOOM_package p);
1068 The <function>ZOOM_connection_package</function> creates a
1069 package for the connection given using the options specified.
1072 Functions <function>ZOOM_package_option_get</function> and
1073 <function>ZOOM_package_option_set</function> gets and sets
1077 <function>ZOOM_package_send</function> sends
1078 the package the via connection specified in
1079 <function>ZOOM_connection_package</function>.
1080 The <parameter>type</parameter> specifies the actual extended service
1081 package type to be sent.
1084 <table frame="top" id="zoom.extendedservices.options">
1085 <title>Extended Service Common Options</title>
1087 <colspec colwidth="4*" colname="name"></colspec>
1088 <colspec colwidth="7*" colname="description"></colspec>
1089 <colspec colwidth="3*" colname="default"></colspec>
1092 <entry>Option</entry>
1093 <entry>Description</entry>
1094 <entry>Default</entry>
1099 <entry>package-name</entry>
1100 <entry>Extended Service Request package name. Must be specified
1101 as part of a request</entry>
1105 <entry>user-id</entry>
1106 <entry>User ID of Extended Service Package. Is a request option</entry>
1110 <entry>function</entry>
1112 Function of package - one of <literal>create</literal>,
1113 <literal>delete</literal>, <literal>modify</literal>. Is
1116 <entry><literal>create</literal></entry>
1119 <entry>waitAction</entry>
1121 Wait action for package. Possible values:
1122 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1123 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1125 <entry><literal>waitIfPossible</literal></entry>
1128 <entry>targetReference</entry>
1130 Target Reference. This is part of the response as returned
1131 by the server. Read it after a successful operation.
1133 <entry><literal>none</literal></entry>
1139 <sect2 id="zoom.item.order"><title>Item Order</title>
1141 For Item Order, type must be set to <literal>itemorder</literal> in
1142 <function>ZOOM_package_send</function>.
1145 <table frame="top" id="zoom.item.order.options">
1146 <title>Item Order Options</title>
1148 <colspec colwidth="4*" colname="name"></colspec>
1149 <colspec colwidth="7*" colname="description"></colspec>
1150 <colspec colwidth="3*" colname="default"></colspec>
1153 <entry>Option</entry>
1154 <entry>Description</entry>
1155 <entry>Default</entry>
1160 <entry>contact-name</entry>
1161 <entry>ILL contact name</entry>
1165 <entry>contact-phone</entry>
1166 <entry>ILL contact phone</entry>
1170 <entry>contact-email</entry>
1171 <entry>ILL contact email</entry>
1175 <entry>itemorder-item</entry>
1176 <entry>Position for item (record) requested. An integer</entry>
1185 <sect2 id="zoom.record.update"><title>Record Update</title>
1187 For Record Update, type must be set to <literal>update</literal> in
1188 <function>ZOOM_package_send</function>.
1191 <table frame="top" id="zoom.record.update.options">
1192 <title>Record Update Options</title>
1194 <colspec colwidth="4*" colname="name"></colspec>
1195 <colspec colwidth="7*" colname="description"></colspec>
1196 <colspec colwidth="3*" colname="default"></colspec>
1199 <entry>Option</entry>
1200 <entry>Description</entry>
1201 <entry>Default</entry>
1206 <entry>action</entry>
1208 The update action. One of
1209 <literal>specialUpdate</literal>,
1210 <literal>recordInsert</literal>,
1211 <literal>recordReplace</literal>,
1212 <literal>recordDelete</literal>,
1213 <literal>elementUpdate</literal>.
1215 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1218 <entry>recordIdOpaque</entry>
1219 <entry>Opaque Record ID</entry>
1223 <entry>recordIdNumber</entry>
1224 <entry>Record ID number</entry>
1228 <entry>record</entry>
1229 <entry>The record itself</entry>
1233 <entry>recordOpaque</entry>
1234 <entry>Specifies an opaque record which is
1235 encoded as an ASN.1 ANY type with the OID as tiven by option
1236 <literal>syntax</literal> (see below).
1237 Option <literal>recordOpaque</literal> is an alternative
1238 to record - and <literal>record</literal> option (above) is
1239 ignored if recordOpaque is set. This option is only available in
1240 YAZ 3.0.35 and later and is meant to facilitate Updates with
1246 <entry>syntax</entry>
1247 <entry>The record syntax (transfer syntax). Is a string that
1248 is a known record syntax.
1250 <entry>no syntax</entry>
1253 <entry>databaseName</entry>
1254 <entry>Database from connection object</entry>
1255 <entry>Default</entry>
1258 <entry>correlationInfo.note</entry>
1259 <entry>Correlation Info Note (string)</entry>
1263 <entry>correlationInfo.id</entry>
1264 <entry>Correlation Info ID (integer)</entry>
1268 <entry>elementSetName</entry>
1269 <entry>Element Set for Record</entry>
1273 <entry>updateVersion</entry>
1274 <entry>Record Update version which holds one of the values
1275 1, 2 or 3. Each version has a distinct OID:
1277 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1279 (second version) and
1280 1.2.840.10003.9.5.1.1
1281 (<ulink url="&url.z39.50.extupdate3;">third and
1282 newest version</ulink>).
1292 <sect2 id="zoom.database.create"><title>Database Create</title>
1294 For Database Create, type must be set to <literal>create</literal> in
1295 <function>ZOOM_package_send</function>.
1298 <table frame="top" id="zoom.database.create.options">
1299 <title>Database Create Options</title>
1301 <colspec colwidth="4*" colname="name"></colspec>
1302 <colspec colwidth="7*" colname="description"></colspec>
1303 <colspec colwidth="3*" colname="default"></colspec>
1306 <entry>Option</entry>
1307 <entry>Description</entry>
1308 <entry>Default</entry>
1313 <entry>databaseName</entry>
1314 <entry>Database from connection object</entry>
1315 <entry>Default</entry>
1322 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1324 For Database Drop, type must be set to <literal>drop</literal> in
1325 <function>ZOOM_package_send</function>.
1328 <table frame="top" id="zoom.database.drop.options">
1329 <title>Database Drop Options</title>
1331 <colspec colwidth="4*" colname="name"></colspec>
1332 <colspec colwidth="7*" colname="description"></colspec>
1333 <colspec colwidth="3*" colname="default"></colspec>
1336 <entry>Option</entry>
1337 <entry>Description</entry>
1338 <entry>Default</entry>
1343 <entry>databaseName</entry>
1344 <entry>Database from connection object</entry>
1345 <entry>Default</entry>
1352 <sect2 id="zoom.commit"><title>Commit Operation</title>
1354 For Commit, type must be set to <literal>commit</literal> in
1355 <function>ZOOM_package_send</function>.
1359 <sect2 id="zoom.extended.services.behavior">
1360 <title>Protocol behavior</title>
1362 All the extended services are Z39.50-only.
1366 The database create, drop and commit services are privately defined
1368 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1375 <sect1 id="zoom.options"><title>Options</title>
1377 Most &zoom; objects provide a way to specify options to change behavior.
1378 From an implementation point of view a set of options is just like
1379 an associative array / hash.
1382 ZOOM_options ZOOM_options_create(void);
1384 ZOOM_options ZOOM_options_create_with_parent(ZOOM_options parent);
1386 void ZOOM_options_destroy(ZOOM_options opt);
1389 const char *ZOOM_options_get(ZOOM_options opt, const char *name);
1391 void ZOOM_options_set(ZOOM_options opt, const char *name,
1395 typedef const char *(*ZOOM_options_callback)
1396 (void *handle, const char *name);
1398 ZOOM_options_callback
1399 ZOOM_options_set_callback(ZOOM_options opt,
1400 ZOOM_options_callback c,
1404 <sect1 id="zoom.events"><title>Events</title>
1406 If you're developing non-blocking applications, you have to deal
1410 int ZOOM_event(int no, ZOOM_connection *cs);
1413 The <function>ZOOM_event</function> executes pending events for
1414 a number of connections. Supply the number of connections in
1415 <literal>no</literal> and an array of connections in
1416 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1417 A pending event could be a sending a search, receiving a response,
1419 When an event has occurred for one of the connections, this function
1420 returns a positive integer <literal>n</literal> denoting that an event
1421 occurred for connection <literal>cs[n-1]</literal>.
1422 When no events are pending for the connections, a value of zero is
1424 To ensure that all outstanding requests are performed call this function
1425 repeatedly until zero is returned.
1428 If <function>ZOOM_event</function> returns and returns non-zero, the
1429 last event that occurred can be expected.
1432 int ZOOM_connection_last_event(ZOOM_connection cs);
1435 <function>ZOOM_connection_last_event</function> returns an event type
1436 (integer) for the last event.
1439 <table frame="top" id="zoom.event.ids">
1440 <title>ZOOM Event IDs</title>
1442 <colspec colwidth="4*" colname="name"></colspec>
1443 <colspec colwidth="7*" colname="description"></colspec>
1446 <entry>Event</entry>
1447 <entry>Description</entry>
1452 <entry>ZOOM_EVENT_NONE</entry>
1453 <entry>No event has occurred</entry>
1456 <entry>ZOOM_EVENT_CONNECT</entry>
1457 <entry>TCP/IP connect has initiated</entry>
1460 <entry>ZOOM_EVENT_SEND_DATA</entry>
1461 <entry>Data has been transmitted (sending)</entry>
1464 <entry>ZOOM_EVENT_RECV_DATA</entry>
1465 <entry>Data has been received)</entry>
1468 <entry>ZOOM_EVENT_TIMEOUT</entry>
1469 <entry>Timeout</entry>
1472 <entry>ZOOM_EVENT_UNKNOWN</entry>
1473 <entry>Unknown event</entry>
1476 <entry>ZOOM_EVENT_SEND_APDU</entry>
1477 <entry>An APDU has been transmitted (sending)</entry>
1480 <entry>ZOOM_EVENT_RECV_APDU</entry>
1481 <entry>An APDU has been received</entry>
1484 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1485 <entry>A result-set record has been received</entry>
1488 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1489 <entry>A search result been received</entry>
1497 <!-- Keep this comment at the end of the file
1502 sgml-minimize-attributes:nil
1503 sgml-always-quote-attributes:t
1506 sgml-parent-document: "yaz.xml"
1507 sgml-local-catalogs: nil
1508 sgml-namecase-general:t