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>
294 If either option <literal>lang</literal> or <literal>charset</literal>
296 <ulink url="&url.z39.50.charneg;">
297 Character Set and Language Negotiation</ulink> is in effect.
300 int ZOOM_connection_error(ZOOM_connection c, const char **cp,
301 const char **addinfo);
302 int ZOOM_connection_error_x(ZOOM_connection c, const char **cp,
303 const char **addinfo, const char **dset);
306 Function <function>ZOOM_connection_error</function> checks for
307 errors for the last operation(s) performed. The function returns
308 zero if no errors occurred; non-zero otherwise indicating the error.
309 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
310 holds messages for the error and additional-info if passed as
311 non-<literal>NULL</literal>. Function
312 <function>ZOOM_connection_error_x</function> is an extended version
313 of <function>ZOOM_connection_error</function> that is capable of
314 returning name of diagnostic set in <parameter>dset</parameter>.
316 <sect2 id="zoom-connection-z39.50">
317 <title>Z39.50 Protocol behavior</title>
319 The calls <function>ZOOM_connection_new</function> and
320 <function>ZOOM_connection_connect</function> establishes a TCP/IP
321 connection and sends an Initialize Request to the target if
322 possible. In addition, the calls waits for an Initialize Response
323 from the target and the result is inspected (OK or rejected).
326 If <literal>proxy</literal> is set then the client will establish
327 a TCP/IP connection with the peer as specified by the
328 <literal>proxy</literal> host and the hostname as part of the
329 connect calls will be set as part of the Initialize Request.
330 The proxy server will then "forward" the PDU's transparently
331 to the target behind the proxy.
334 For the authentication parameters, if option <literal>user</literal>
335 is set and both options <literal>group</literal> and
336 <literal>pass</literal> are unset, then Open style
337 authentication is used (Version 2/3) in which case the username
338 is usually followed by a slash, then by a password.
339 If either <literal>group</literal>
340 or <literal>pass</literal> is set then idPass authentication
341 (Version 3 only) is used. If none of the options are set, no
342 authentication parameters are set as part of the Initialize Request
346 When option <literal>async</literal> is 1, it really means that
347 all network operations are postponed (and queued) until the
348 function <literal>ZOOM_event</literal> is invoked. When doing so
349 it doesn't make sense to check for errors after
350 <literal>ZOOM_connection_new</literal> is called since that
351 operation "connecting - and init" is still incomplete and the
352 API cannot tell the outcome (yet).
355 <sect2 id="zoom.sru.init.behavior">
356 <title>SRU Protocol behavior</title>
358 The SRU protocol doesn't feature an Inititialize Request, so
359 the connection phase merely establishes a TCP/IP connection
360 with the SOAP service.
362 <para>Most of the ZOOM connection options do not
363 affect SRU and they are ignored. However, future versions
364 of &yaz; might honor <literal>implementationName</literal> and
365 put that as part of User-Agent header for HTTP requests.
368 The <literal>charset</literal> is used in the Content-Type header
373 <sect1 id="zoom.query"><title>Queries</title>
375 Query objects represents queries.
378 ZOOM_query ZOOM_query_create(void);
380 void ZOOM_query_destroy(ZOOM_query q);
382 int ZOOM_query_prefix(ZOOM_query q, const char *str);
384 int ZOOM_query_cql(ZOOM_query s, const char *str);
386 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
389 Create query objects using <function>ZOOM_query_create</function>
390 and destroy them by calling <function>ZOOM_query_destroy</function>.
391 RPN-queries can be specified in <link linkend="PQF">PQF</link>
392 notation by using the
393 function <function>ZOOM_query_prefix</function>.
394 The <function>ZOOM_query_cql</function> specifies a CQL
395 query to be sent to the server/target.
396 More query types will be added in future versions of &yaz;, such as
397 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
398 etc. In addition to a search, a sort criteria may be set. Function
399 <function>ZOOM_query_sortby</function> specifies a
400 sort criteria using the same string notation for sort as offered by
401 the <link linkend="sortspec">YAZ client</link>.
403 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
405 The query object is just an interface for the member Query
406 in the SearchRequest. The sortby-function is an interface to the
407 sortSequence member of the SortRequest.
411 <sect1 id="zoom.resultsets"><title>Result sets</title>
413 The result set object is a container for records returned from
417 ZOOM_resultset ZOOM_connection_search(ZOOM_connection, ZOOM_query q);
419 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
421 void ZOOM_resultset_destroy(ZOOM_resultset r);
424 Function <function>ZOOM_connection_search</function> creates
425 a result set given a connection and query.
426 Destroy a result set by calling
427 <function>ZOOM_resultset_destroy</function>.
428 Simple clients may using PQF only may use function
429 <function>ZOOM_connection_search_pqf</function> in which case
430 creating query objects is not necessary.
433 void ZOOM_resultset_option_set(ZOOM_resultset r,
434 const char *key, const char *val);
436 const char *ZOOM_resultset_option_get(ZOOM_resultset r, const char *key);
438 size_t ZOOM_resultset_size(ZOOM_resultset r);
441 Functions <function>ZOOM_resultset_options_set</function> and
442 <function>ZOOM_resultset_get</function> sets and gets an option
443 for a result set similar to <function>ZOOM_connection_option_get</function>
444 and <function>ZOOM_connection_option_set</function>.
447 The number of hits also called result-count is returned by
448 function <function>ZOOM_resultset_size</function>.
450 <table id="zoom.resultset.options"
451 frame="top"><title>ZOOM Result set Options</title>
453 <colspec colwidth="4*" colname="name"></colspec>
454 <colspec colwidth="7*" colname="description"></colspec>
455 <colspec colwidth="2*" colname="default"></colspec>
458 <entry>Option</entry>
459 <entry>Description</entry>
460 <entry>Default</entry>
465 start</entry><entry>Offset of first record to be
466 retrieved from target. First record has offset 0 unlike the
467 protocol specifications where first record has position 1.
468 This option affects ZOOM_resultset_search and
469 ZOOM_resultset_search_pqf and must be set before any of
470 these functions are invoked. If a range of
471 records must be fetched manually after search,
472 function ZOOM_resultset_records should be used.
473 </entry><entry>0</entry></row>
475 count</entry><entry>Number of records to be retrieved.
476 This option affects ZOOM_resultset_search and
477 ZOOM_resultset_search_pqf and must be set before any of
478 these functions are invoked.
479 </entry><entry>0</entry></row>
481 presentChunk</entry><entry>The number of records to be
482 requested from the server in each chunk (present request). The
483 value 0 means to request all the records in a single chunk.
484 (The old <literal>step</literal>
485 option is also supported for the benefit of old applications.)
486 </entry><entry>0</entry></row>
488 elementSetName</entry><entry>Element-Set name of records.
489 Most targets should honor element set name <literal>B</literal>
490 and <literal>F</literal> for brief and full respectively.
491 </entry><entry>none</entry></row>
493 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
494 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
495 </entry><entry>none</entry></row>
497 schema</entry><entry>Schema for retrieval, such as
498 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
499 </entry><entry>none</entry></row>
501 setname</entry><entry>Name of Result Set (Result Set ID).
502 If this option isn't set, the ZOOM module will automatically
503 allocate a result set name.
504 </entry><entry>default</entry></row>
506 rpnCharset</entry><entry>Character set for RPN terms.
507 If this is set, ZOOM C will assume that the ZOOM application is
508 running UTF-8. Terms in RPN queries are then converted to the
509 rpnCharset. If this is unset, ZOOM C will not assume any encoding
510 of RPN terms and no conversion is performed.
511 </entry><entry>none</entry></row>
516 For servers that support Search Info report, the following
517 options may be read using <function>ZOOM_resultset_get</function>.
518 This detailed information is read after a successful search has
522 This information is a list of of items, where each item is
523 information about a term or subquery. All items in the list
525 <literal>SearchResult.</literal><replaceable>no</replaceable>
526 where no presents the item number (0=first, 1=second).
527 Read <literal>searchresult.size</literal> to determine the
530 <table id="zoom.search.info.report.options"
531 frame="top"><title>Search Info Report Options</title>
533 <colspec colwidth="4*" colname="name"></colspec>
534 <colspec colwidth="7*" colname="description"></colspec>
537 <entry>Option</entry>
538 <entry>Description</entry>
543 <entry>searchresult.size</entry>
545 number of search result entries. This option is-nonexistant
546 if no entries are returned by the server.
550 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
551 <entry>sub query ID</entry>
554 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
555 <entry>result count for item (number of hits)</entry>
558 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
559 <entry>subquery term</entry>
563 searchresult.<replaceable>no</replaceable>.interpretation.term
565 <entry>interpretation term</entry>
569 searchresult.<replaceable>no</replaceable>.recommendation.term
571 <entry>recommendation term</entry>
576 <sect2 id="zoom.z3950.resultset.behavior">
577 <title>Z39.50 Protocol behavior</title>
579 The creation of a result set involves at least a SearchRequest
580 - SearchResponse protocol handshake. Following that, if a sort
581 criteria was specified as part of the query, a SortRequest -
582 SortResponse handshake takes place. Note that it is necessary to
583 perform sorting before any retrieval takes place, so no records will
584 be returned from the target as part of the SearchResponse because these
585 would be unsorted. Hence, piggyback is disabled when sort criteria
586 are set. Following Search - and a possible sort - Retrieval takes
587 place - as one or more Present Requests/Response pairs being
591 The API allows for two different modes for retrieval. A high level
592 mode which is somewhat more powerful and a low level one.
593 The low level is enabled when searching on a Connection object
594 for which the settings
595 <literal>smallSetUpperBound</literal>,
596 <literal>mediumSetPresentNumber</literal> and
597 <literal>largeSetLowerBound</literal> are set. The low level mode
598 thus allows you to precisely set how records are returned as part
599 of a search response as offered by the Z39.50 protocol.
600 Since the client may be retrieving records as part of the
601 search response, this mode doesn't work well if sorting is used.
604 The high-level mode allows you to fetch a range of records from
605 the result set with a given start offset. When you use this mode
606 the client will automatically use piggyback if that is possible
607 with the target and perform one or more present requests as needed.
608 Even if the target returns fewer records as part of a present response
609 because of a record size limit, etc. the client will repeat sending
610 present requests. As an example, if option <literal>start</literal>
611 is 0 (default) and <literal>count</literal> is 4, and
612 <literal>piggyback</literal> is 1 (default) and no sorting criteria
613 is specified, then the client will attempt to retrieve the 4
614 records as part the search response (using piggyback). On the other
615 hand, if either <literal>start</literal> is positive or if
616 a sorting criteria is set, or if <literal>piggyback</literal>
617 is 0, then the client will not perform piggyback but send Present
621 If either of the options <literal>mediumSetElementSetName</literal> and
622 <literal>smallSetElementSetName</literal> are unset, the value
623 of option <literal>elementSetName</literal> is used for piggyback
624 searches. This means that for the high-level mode you only have
625 to specify one elementSetName option rather than three.
628 <sect2 id="zoom.sru.resultset.behavior">
629 <title>SRU Protocol behavior</title>
631 Current version of &yaz; does not take advantage of a result set id
632 returned by the SRU server. Future versions might do, however.
633 Since, the ZOOM driver does not save result set IDs any
634 present (retrieval) is transformed to a SRU SearchRetrieveRequest
635 with same query but, possibly, different offsets.
638 Option <literal>schema</literal> specifies SRU schema
639 for retrieval. However, options <literal>elementSetName</literal> and
640 <literal>preferredRecordSyntax</literal> are ignored.
643 Options <literal>start</literal> and <literal>count</literal>
644 are supported by SRU.
645 The remaining options
646 <literal>piggyback</literal>,
647 <literal>smallSetUpperBound</literal>,
648 <literal>largeSetLowerBound</literal>,
649 <literal>mediumSetPresentNumber</literal>,
650 <literal>mediumSetElementSetName</literal>,
651 <literal>smallSetElementSetName</literal> are
655 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
656 If PQF is used, however, the PQF query is transferred anyway
657 using non-standard element <literal>pQuery</literal> in
658 SRU SearchRetrieveRequest.
661 Unfortunately, SRU does not define a database setting. Hence,
662 <literal>databaseName</literal> is unsupported and ignored.
663 However, the path part in host parameter for functions
664 <function>ZOOM_connecton_new</function> and
665 <function>ZOOM_connection_connect</function> acts as a
666 database (at least for the &yaz; SRU server).
670 <sect1 id="zoom.records"><title>Records</title>
672 A record object is a retrieval record on the client side -
673 created from result sets.
676 void ZOOM_resultset_records(ZOOM_resultset r,
678 size_t start, size_t count);
679 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
681 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
684 int ZOOM_record_error(ZOOM_record rec, const char **msg,
685 const char **addinfo, const char **diagset);
687 ZOOM_record ZOOM_record_clone(ZOOM_record rec);
689 void ZOOM_record_destroy(ZOOM_record rec);
692 References to temporary records are returned by functions
693 <function>ZOOM_resultset_records</function> or
694 <function>ZOOM_resultset_record</function>.
697 If a persistent reference to a record is desired
698 <function>ZOOM_record_clone</function> should be used.
699 It returns a record reference that should be destroyed
700 by a call to <function>ZOOM_record_destroy</function>.
703 A single record is returned by function
704 <function>ZOOM_resultset_record</function> that takes a
705 position as argument. First record has position zero.
706 If no record could be obtained <literal>NULL</literal> is returned.
709 Error information for a record can be checked with
710 <function>ZOOM_record_error</function> which returns non-zero
711 (error code) if record is in error, called <emphasis>Surrogate
712 Diagnostics</emphasis> in Z39.50.
715 Function <function>ZOOM_resultset_records</function> retrieves
716 a number of records from a result set. Parameter <literal>start</literal>
717 and <literal>count</literal> specifies the range of records to
718 be returned. Upon completion array
719 <literal>recs[0], ..recs[count-1]</literal>
720 holds record objects for the records. The array of records
721 <literal>recs</literal> should be allocated prior the call
722 <function>ZOOM_resultset_records</function>. Note that for those
723 records that couldn't be retrieved from the target
724 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
726 <para id="zoom.record.get">
727 In order to extract information about a single record,
728 <function>ZOOM_record_get</function> is provided. The
729 function returns a pointer to certain record information. The
730 nature (type) of the pointer depends on the parameter,
731 <parameter>type</parameter>.
734 The <parameter>type</parameter> is a string of the format:
737 <replaceable>form</replaceable>[;charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]][;format=<replaceable>v</replaceable>]
740 where <replaceable>form</replaceable> specifies the format of the
741 returned record, <replaceable>from</replaceable>
742 specifies the character set of the record in its original form
743 (as returned by the server), <replaceable>to</replaceable> specifies
744 the output (returned)
745 character set encoding.
746 If charset is not given, then no character set conversion takes place.
747 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
750 The format argument controls whether record data should be XML
751 pretty-printed (post process operation).
752 It is enabled only if format value <replaceable>v</replaceable> is
753 <literal>1</literal> and the record content is XML well-formed.
756 In addition, for certain types, the length
757 <literal>len</literal> passed will be set to the size in bytes of
758 the returned information.
761 The following are the supported values for <replaceable>form</replaceable>.
763 <varlistentry><term><literal>database</literal></term>
764 <listitem><para>Database of record is returned
765 as a C null-terminated string. Return type
766 <literal>const char *</literal>.
769 <varlistentry><term><literal>syntax</literal></term>
770 <listitem><para>The transfer syntax of the record is returned
771 as a C null-terminated string containing the symbolic name of
772 the record syntax, e.g. <literal>Usmarc</literal>. Return type
774 <literal>const char *</literal>.
777 <varlistentry><term><literal>schema</literal></term>
778 <listitem><para>The schema of the record is returned
779 as a C null-terminated string. Return type is
780 <literal>const char *</literal>.
783 <varlistentry><term><literal>render</literal></term>
784 <listitem><para>The record is returned in a display friendly
785 format. Upon completion buffer is returned
786 (type <literal>const char *</literal>) and length is stored in
787 <literal>*len</literal>.
790 <varlistentry><term><literal>raw</literal></term>
791 <listitem><para>The record is returned in the internal
792 YAZ specific format. For GRS-1, Explain, and others, the
793 raw data is returned as type
794 <literal>Z_External *</literal> which is just the type for
795 the member <literal>retrievalRecord</literal> in
796 type <literal>NamePlusRecord</literal>.
797 For SUTRS and octet aligned record (including all MARCs) the
798 octet buffer is returned and the length of the buffer.
801 <varlistentry><term><literal>xml</literal></term>
802 <listitem><para>The record is returned in XML if possible.
803 SRU and Z39.50 records with transfer syntax XML are
804 returned verbatim. MARC records are returned in
805 <ulink url="&url.marcxml;">
808 (converted from ISO2709 to MARCXML by YAZ).
809 OPAC records are also converted to XML and the
810 bibliographic record is converted to MARCXML (when possible).
811 GRS-1 records are not supported for this form.
812 Upon completion, the XML buffer is returned
813 (type <literal>const char *</literal>) and length is stored in
814 <literal>*len</literal>.
817 <varlistentry><term><literal>opac</literal></term>
818 <listitem><para>OPAC information for record is returned in XML
819 if an OPAC record is present at the position given. If no
820 OPAC record is present, a NULL pointer is returned.
823 <varlistentry><term><literal>txml</literal></term>
824 <listitem><para>The record is returned in TurboMARC if possible.
825 SRU and Z39.50 records with transfer syntax XML are
826 returned verbatim. MARC records are returned in
827 <link linkend="tools.turbomarc">
830 (converted from ISO2709 to TurboMARC by YAZ).
831 Upon completion, the XML buffer is returned
832 (type <literal>const char *</literal>) and length is stored in
833 <literal>*len</literal>.
840 <ulink url="&url.marc21;">MARC21</ulink>
842 <ulink url="&url.marc8;">MARC-8</ulink>
843 character set encoding.
844 An application that wishes to display in Latin-1 would use
846 render; charset=marc8,iso-8859-1
849 <sect2 id="zoom.z3950.record.behavior">
850 <title>Z39.50 Protocol behavior</title>
852 The functions <function>ZOOM_resultset_record</function> and
853 <function>ZOOM_resultset_records</function> inspects the client-side
854 record cache. Records not found in cache are fetched using
856 The functions may block (and perform network I/O) - even though option
857 <literal>async</literal> is 1, because they return records objects.
858 (and there's no way to return records objects without retrieving them!).
861 There is a trick, however, in the usage of function
862 <function>ZOOM_resultset_records</function> that allows for
863 delayed retrieval (and makes it non-blocking). By using
864 a null pointer for <parameter>recs</parameter> you're indicating
865 you're not interested in getting records objects
866 <emphasis>now</emphasis>.
869 <sect2 id="zoom.sru.record.behavior">
870 <title>SRU Protocol behavior</title>
872 The ZOOM driver for SRU treats records returned by a SRU server
873 as if they where Z39.50 records with transfer syntax XML and
874 no element set name or database name.
878 <sect1 id="zoom.scan"><title>Scan</title>
880 This section describes an interface for Scan. Scan is not an
881 official part of the ZOOM model yet. The result of a scan operation
882 is the <literal>ZOOM_scanset</literal> which is a set of terms
883 returned by a target.
887 The Scan interface is supported for both Z39.50 and SRU.
891 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
892 const char *startpqf);
894 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
897 size_t ZOOM_scanset_size(ZOOM_scanset scan);
899 const char *ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
900 size_t *occ, size_t *len);
902 const char *ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
903 size_t *occ, size_t *len);
905 void ZOOM_scanset_destroy(ZOOM_scanset scan);
907 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
910 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
914 The scan set is created by function
915 <function>ZOOM_connection_scan</function> which performs a scan
916 operation on the connection using the specified
917 <parameter>startpqf</parameter>.
918 If the operation was successful, the size of the scan set can be
919 retrieved by a call to <function>ZOOM_scanset_size</function>.
920 Like result sets, the items are numbered 0,..size-1.
921 To obtain information about a particular scan term, call function
922 <function>ZOOM_scanset_term</function>. This function takes
923 a scan set offset <literal>pos</literal> and returns a pointer
924 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
926 If present, the <literal>occ</literal> and <literal>len</literal>
927 are set to the number of occurrences and the length
928 of the actual term respectively.
929 <function>ZOOM_scanset_display_term</function> is similar to
930 <function>ZOOM_scanset_term</function> except that it returns
931 the <emphasis>display term</emphasis> rather than the raw term.
932 In a few cases, the term is different from display term. Always
933 use the display term for display and the raw term for subsequent
934 scan operations (to get more terms, next scan result, etc).
937 A scan set may be freed by a call to function
938 <function>ZOOM_scanset_destroy</function>.
939 Functions <function>ZOOM_scanset_option_get</function> and
940 <function>ZOOM_scanset_option_set</function> retrieves and sets
941 an option respectively.
945 The <parameter>startpqf</parameter> is a subset of PQF, namely
946 the Attributes+Term part. Multiple <literal>@attr</literal> can
947 be used. For example to scan in title (complete) phrases:
949 @attr 1=4 @attr 6=2 "science o"
954 The <function>ZOOM_connecton_scan1</function> is a newer and
955 more generic alternative to <function>ZOOM_connection_scan</function>
956 which allows to use both CQL and PQF for Scan.
959 <table frame="top" id="zoom.scanset.options">
960 <title>ZOOM Scan Set Options</title>
962 <colspec colwidth="4*" colname="name"></colspec>
963 <colspec colwidth="7*" colname="description"></colspec>
964 <colspec colwidth="2*" colname="default"></colspec>
967 <entry>Option</entry>
968 <entry>Description</entry>
969 <entry>Default</entry>
974 number</entry><entry>Number of Scan Terms requested in next scan.
975 After scan it holds the actual number of terms returned.
976 </entry><entry>20</entry></row>
978 position</entry><entry>Preferred Position of term in response
979 in next scan; actual position after completion of scan.
980 </entry><entry>1</entry></row>
982 stepSize</entry><entry>Step Size
983 </entry><entry>0</entry></row>
985 scanStatus</entry><entry>An integer indicating the Scan Status
987 </entry><entry>0</entry></row>
989 rpnCharset</entry><entry>Character set for RPN terms.
990 If this is set, ZOOM C will assume that the ZOOM application is
991 running UTF-8. Terms in RPN queries are then converted to the
992 rpnCharset. If this is unset, ZOOM C will not assume any encoding
993 of RPN terms and no conversion is performed.
994 </entry><entry>none</entry></row>
1000 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
1002 ZOOM offers an interface to a subset of the Z39.50 extended services
1003 as well as a few privately defined ones:
1008 Z39.50 Item Order (ILL).
1009 See <xref linkend="zoom.item.order"/>.
1014 Record Update. This allows a client to insert, modify or delete
1016 See <xref linkend="zoom.record.update"/>.
1021 Database Create. This a non-standard feature. Allows a client
1022 to create a database.
1023 See <xref linkend="zoom.database.create"/>.
1028 Database Drop. This a non-standard feature. Allows a client
1029 to delete/drop a database.
1030 See <xref linkend="zoom.database.drop"/>.
1035 Commit operation. This a non-standard feature. Allows a client
1036 to commit operations.
1037 See <xref linkend="zoom.commit"/>.
1040 <!-- all the ILL PDU options should go here too -->
1043 To create an extended service operation a <literal>ZOOM_package</literal>
1044 must be created. The operation is a five step operation. The
1045 package is created, package is configured by means of options,
1046 the package is send, result is inspected (by means of options),
1047 the package is destroyed.
1050 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1051 ZOOM_options options);
1053 const char *ZOOM_package_option_get(ZOOM_package p,
1055 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1057 void ZOOM_package_send(ZOOM_package p, const char *type);
1059 void ZOOM_package_destroy(ZOOM_package p);
1062 The <function>ZOOM_connection_package</function> creates a
1063 package for the connection given using the options specified.
1066 Functions <function>ZOOM_package_option_get</function> and
1067 <function>ZOOM_package_option_set</function> gets and sets
1071 <function>ZOOM_package_send</function> sends
1072 the package the via connection specified in
1073 <function>ZOOM_connection_package</function>.
1074 The <parameter>type</parameter> specifies the actual extended service
1075 package type to be sent.
1078 <table frame="top" id="zoom.extendedservices.options">
1079 <title>Extended Service Common Options</title>
1081 <colspec colwidth="4*" colname="name"></colspec>
1082 <colspec colwidth="7*" colname="description"></colspec>
1083 <colspec colwidth="3*" colname="default"></colspec>
1086 <entry>Option</entry>
1087 <entry>Description</entry>
1088 <entry>Default</entry>
1093 <entry>package-name</entry>
1094 <entry>Extended Service Request package name. Must be specified
1095 as part of a request</entry>
1099 <entry>user-id</entry>
1100 <entry>User ID of Extended Service Package. Is a request option</entry>
1104 <entry>function</entry>
1106 Function of package - one of <literal>create</literal>,
1107 <literal>delete</literal>, <literal>modify</literal>. Is
1110 <entry><literal>create</literal></entry>
1113 <entry>waitAction</entry>
1115 Wait action for package. Possible values:
1116 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1117 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1119 <entry><literal>waitIfPossible</literal></entry>
1122 <entry>targetReference</entry>
1124 Target Reference. This is part of the response as returned
1125 by the server. Read it after a successful operation.
1127 <entry><literal>none</literal></entry>
1133 <sect2 id="zoom.item.order"><title>Item Order</title>
1135 For Item Order, type must be set to <literal>itemorder</literal> in
1136 <function>ZOOM_package_send</function>.
1139 <table frame="top" id="zoom.item.order.options">
1140 <title>Item Order Options</title>
1142 <colspec colwidth="4*" colname="name"></colspec>
1143 <colspec colwidth="7*" colname="description"></colspec>
1144 <colspec colwidth="3*" colname="default"></colspec>
1147 <entry>Option</entry>
1148 <entry>Description</entry>
1149 <entry>Default</entry>
1154 <entry>contact-name</entry>
1155 <entry>ILL contact name</entry>
1159 <entry>contact-phone</entry>
1160 <entry>ILL contact phone</entry>
1164 <entry>contact-email</entry>
1165 <entry>ILL contact email</entry>
1169 <entry>itemorder-item</entry>
1170 <entry>Position for item (record) requested. An integer</entry>
1179 <sect2 id="zoom.record.update"><title>Record Update</title>
1181 For Record Update, type must be set to <literal>update</literal> in
1182 <function>ZOOM_package_send</function>.
1185 <table frame="top" id="zoom.record.update.options">
1186 <title>Record Update Options</title>
1188 <colspec colwidth="4*" colname="name"></colspec>
1189 <colspec colwidth="7*" colname="description"></colspec>
1190 <colspec colwidth="3*" colname="default"></colspec>
1193 <entry>Option</entry>
1194 <entry>Description</entry>
1195 <entry>Default</entry>
1200 <entry>action</entry>
1202 The update action. One of
1203 <literal>specialUpdate</literal>,
1204 <literal>recordInsert</literal>,
1205 <literal>recordReplace</literal>,
1206 <literal>recordDelete</literal>,
1207 <literal>elementUpdate</literal>.
1209 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1212 <entry>recordIdOpaque</entry>
1213 <entry>Opaque Record ID</entry>
1217 <entry>recordIdNumber</entry>
1218 <entry>Record ID number</entry>
1222 <entry>record</entry>
1223 <entry>The record itself</entry>
1227 <entry>recordOpaque</entry>
1228 <entry>Specifies an opaque record which is
1229 encoded as an ASN.1 ANY type with the OID as tiven by option
1230 <literal>syntax</literal> (see below).
1231 Option <literal>recordOpaque</literal> is an alternative
1232 to record - and <literal>record</literal> option (above) is
1233 ignored if recordOpaque is set. This option is only available in
1234 YAZ 3.0.35 and later and is meant to facilitate Updates with
1240 <entry>syntax</entry>
1241 <entry>The record syntax (transfer syntax). Is a string that
1242 is a known record syntax.
1244 <entry>no syntax</entry>
1247 <entry>databaseName</entry>
1248 <entry>Database from connection object</entry>
1249 <entry>Default</entry>
1252 <entry>correlationInfo.note</entry>
1253 <entry>Correlation Info Note (string)</entry>
1257 <entry>correlationInfo.id</entry>
1258 <entry>Correlation Info ID (integer)</entry>
1262 <entry>elementSetName</entry>
1263 <entry>Element Set for Record</entry>
1267 <entry>updateVersion</entry>
1268 <entry>Record Update version which holds one of the values
1269 1, 2 or 3. Each version has a distinct OID:
1271 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1273 (second version) and
1274 1.2.840.10003.9.5.1.1
1275 (<ulink url="&url.z39.50.extupdate3;">third and
1276 newest version</ulink>).
1286 <sect2 id="zoom.database.create"><title>Database Create</title>
1288 For Database Create, type must be set to <literal>create</literal> in
1289 <function>ZOOM_package_send</function>.
1292 <table frame="top" id="zoom.database.create.options">
1293 <title>Database Create Options</title>
1295 <colspec colwidth="4*" colname="name"></colspec>
1296 <colspec colwidth="7*" colname="description"></colspec>
1297 <colspec colwidth="3*" colname="default"></colspec>
1300 <entry>Option</entry>
1301 <entry>Description</entry>
1302 <entry>Default</entry>
1307 <entry>databaseName</entry>
1308 <entry>Database from connection object</entry>
1309 <entry>Default</entry>
1316 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1318 For Database Drop, type must be set to <literal>drop</literal> in
1319 <function>ZOOM_package_send</function>.
1322 <table frame="top" id="zoom.database.drop.options">
1323 <title>Database Drop Options</title>
1325 <colspec colwidth="4*" colname="name"></colspec>
1326 <colspec colwidth="7*" colname="description"></colspec>
1327 <colspec colwidth="3*" colname="default"></colspec>
1330 <entry>Option</entry>
1331 <entry>Description</entry>
1332 <entry>Default</entry>
1337 <entry>databaseName</entry>
1338 <entry>Database from connection object</entry>
1339 <entry>Default</entry>
1346 <sect2 id="zoom.commit"><title>Commit Operation</title>
1348 For Commit, type must be set to <literal>commit</literal> in
1349 <function>ZOOM_package_send</function>.
1353 <sect2 id="zoom.extended.services.behavior">
1354 <title>Protocol behavior</title>
1356 All the extended services are Z39.50-only.
1360 The database create, drop and commit services are privately defined
1362 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1369 <sect1 id="zoom.options"><title>Options</title>
1371 Most &zoom; objects provide a way to specify options to change behavior.
1372 From an implementation point of view a set of options is just like
1373 an associative array / hash.
1376 ZOOM_options ZOOM_options_create(void);
1378 ZOOM_options ZOOM_options_create_with_parent(ZOOM_options parent);
1380 void ZOOM_options_destroy(ZOOM_options opt);
1383 const char *ZOOM_options_get(ZOOM_options opt, const char *name);
1385 void ZOOM_options_set(ZOOM_options opt, const char *name,
1389 typedef const char *(*ZOOM_options_callback)
1390 (void *handle, const char *name);
1392 ZOOM_options_callback
1393 ZOOM_options_set_callback(ZOOM_options opt,
1394 ZOOM_options_callback c,
1398 <sect1 id="zoom.events"><title>Events</title>
1400 If you're developing non-blocking applications, you have to deal
1404 int ZOOM_event(int no, ZOOM_connection *cs);
1407 The <function>ZOOM_event</function> executes pending events for
1408 a number of connections. Supply the number of connections in
1409 <literal>no</literal> and an array of connections in
1410 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1411 A pending event could be a sending a search, receiving a response,
1413 When an event has occurred for one of the connections, this function
1414 returns a positive integer <literal>n</literal> denoting that an event
1415 occurred for connection <literal>cs[n-1]</literal>.
1416 When no events are pending for the connections, a value of zero is
1418 To ensure that all outstanding requests are performed call this function
1419 repeatedly until zero is returned.
1422 If <function>ZOOM_event</function> returns and returns non-zero, the
1423 last event that occurred can be expected.
1426 int ZOOM_connection_last_event(ZOOM_connection cs);
1429 <function>ZOOM_connection_last_event</function> returns an event type
1430 (integer) for the last event.
1433 <table frame="top" id="zoom.event.ids">
1434 <title>ZOOM Event IDs</title>
1436 <colspec colwidth="4*" colname="name"></colspec>
1437 <colspec colwidth="7*" colname="description"></colspec>
1440 <entry>Event</entry>
1441 <entry>Description</entry>
1446 <entry>ZOOM_EVENT_NONE</entry>
1447 <entry>No event has occurred</entry>
1450 <entry>ZOOM_EVENT_CONNECT</entry>
1451 <entry>TCP/IP connect has initiated</entry>
1454 <entry>ZOOM_EVENT_SEND_DATA</entry>
1455 <entry>Data has been transmitted (sending)</entry>
1458 <entry>ZOOM_EVENT_RECV_DATA</entry>
1459 <entry>Data has been received)</entry>
1462 <entry>ZOOM_EVENT_TIMEOUT</entry>
1463 <entry>Timeout</entry>
1466 <entry>ZOOM_EVENT_UNKNOWN</entry>
1467 <entry>Unknown event</entry>
1470 <entry>ZOOM_EVENT_SEND_APDU</entry>
1471 <entry>An APDU has been transmitted (sending)</entry>
1474 <entry>ZOOM_EVENT_RECV_APDU</entry>
1475 <entry>An APDU has been received</entry>
1478 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1479 <entry>A result-set record has been received</entry>
1482 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1483 <entry>A search result been received</entry>
1491 <!-- Keep this comment at the end of the file
1496 sgml-minimize-attributes:nil
1497 sgml-always-quote-attributes:t
1500 sgml-parent-document: "yaz.xml"
1501 sgml-local-catalogs: nil
1502 sgml-namecase-general:t