3 ZOOM_connection_errcode(c)
4 ZOOM_connection_errmsg(c)
5 ZOOM_connection_addinfo(c)
6 ZOOM_connection_addinfo(c)
7 ZOOM_connection_diagset(c);
9 ZOOM_resultset_record_immediate(s, pos)
10 ZOOM_resultset_cache_reset(r)
11 ZOOM_resultset_sort(r, sort_type, sort_spec)
12 ZOOM_resultset_sort1(r, sort_type, sort_spec)
13 ZOOM_options_set_callback(opt, function, handle)
14 ZOOM_options_create_with_parent2(parent1, parent2)
15 ZOOM_options_getl(opt, name, len)
16 ZOOM_options_setl(opt, name, value, len)
17 ZOOM_options_get_bool(opt, name, defa)
18 ZOOM_options_get_int(opt, name, defa)
19 ZOOM_options_set_int(opt, name, value)
20 ZOOM_connection_scan1 (ZOOM_connection c, ZOOM_query startterm)
21 ZOOM_query_cql2rpn(ZOOM_query s, const char *str, ZOOM_connection conn)
23 <chapter id="zoom"><title>ZOOM</title>
25 &zoom; is an acronym for 'Z39.50 Object-Orientation Model' and is
26 an initiative started by Mike Taylor (Mike is from the UK, which
27 explains the peculiar name of the model). The goal of &zoom; is to
28 provide a common Z39.50 client API not bound to a particular
29 programming language or toolkit.
34 A recent addition to &yaz; is SRU support. You can now make
35 SRU ZOOM connections by specifying scheme <literal>http://</literal>
36 for the hostname for a connection. The dialect of SRU used is
37 specified by the value of the connection's <literal>sru</literal>
38 option, which may be SRU over HTTP GET (<literal>get</literal>),
39 SRU over HTTP POST (<literal>post</literal>) or SRW (SRU over
40 SOAP) (<literal>soap</literal>). Using the facility for embedding
41 options in target strings, a connection can be forced to use SRU
42 rather the SRW (the default) by prefixing the target string with
43 <literal>sru=get,</literal>, like this:
44 <literal>sru=get,http://sru.miketaylor.org.uk:80/sru.pl</literal>
49 The lack of a simple Z39.50 client API for &yaz; has become more
50 and more apparent over time. So when the first &zoom; specification
52 an implementation for &yaz; was quickly developed. For the first time, it is
53 now as easy (or easier!) to develop clients than servers with &yaz;. This
54 chapter describes the &zoom; C binding. Before going further, please
55 reconsider whether C is the right programming language for the job.
56 There are other language bindings available for &yaz;, and still
58 are in active development. See the
59 <ulink url="&url.zoom;">ZOOM web-site</ulink> for
64 In order to fully understand this chapter you should read and
65 try the example programs <literal>zoomtst1.c</literal>,
66 <literal>zoomtst2.c</literal>, .. in the <literal>zoom</literal>
71 The C language misses features found in object oriented languages
72 such as C++, Java, etc. For example, you'll have to manually,
73 destroy all objects you create, even though you may think of them as
74 temporary. Most objects has a <literal>_create</literal> - and a
75 <literal>_destroy</literal> variant.
76 All objects are in fact pointers to internal stuff, but you don't see
77 that because of typedefs. All destroy methods should gracefully ignore a
78 <literal>NULL</literal> pointer.
81 In each of the sections below you'll find a sub section called
82 protocol behavior, that describes how the API maps to the Z39.50
85 <sect1 id="zoom-connections"><title>Connections</title>
87 <para>The Connection object is a session with a target.
90 #include <yaz/zoom.h>
92 ZOOM_connection ZOOM_connection_new (const char *host, int portnum);
94 ZOOM_connection ZOOM_connection_create (ZOOM_options options);
96 void ZOOM_connection_connect(ZOOM_connection c, const char *host,
98 void ZOOM_connection_destroy (ZOOM_connection c);
101 Connection objects are created with either function
102 <function>ZOOM_connection_new</function> or
103 <function>ZOOM_connection_create</function>.
104 The former creates and automatically attempts to establish a network
105 connection with the target. The latter doesn't establish
106 a connection immediately, thus allowing you to specify options
107 before establishing network connection using the function
108 <function>ZOOM_connection_connect</function>.
109 If the port number, <literal>portnum</literal>, is zero, the
110 <literal>host</literal> is consulted for a port specification.
111 If no port is given, 210 is used. A colon denotes the beginning of
112 a port number in the host string. If the host string includes a
113 slash, the following part specifies a database for the connection.
116 You can prefix the host with a scheme followed by colon. The
117 default scheme is <literal>tcp</literal> (Z39.50 protocol).
118 The scheme <literal>http</literal> selects SRU over HTTP.
121 You can prefix the scheme-qualified host-string with one or more
123 <literal><parameter>key</parameter>=<parameter>value</parameter></literal>
124 sequences, each of which represents an option to be set into the
125 connection structure <emphasis>before</emphasis> the
126 protocol-level connection is forged and the initialization
127 handshake takes place. This facility can be used to provide
128 authentication credentials, as in host-strings such as:
129 <literal>user=admin,password=halfAm4n,tcp:localhost:8017/db</literal>
132 Connection objects should be destroyed using the function
133 <function>ZOOM_connection_destroy</function>.
136 void ZOOM_connection_option_set(ZOOM_connection c,
137 const char *key, const char *val);
139 void ZOOM_connection_option_setl(ZOOM_connection c,
141 const char *val, int len);
143 const char *ZOOM_connection_option_get(ZOOM_connection c,
145 const char *ZOOM_connection_option_getl(ZOOM_connection c,
150 The functions <function>ZOOM_connection_option_set</function> and
151 <function>ZOOM_connection_option_setl</function> allows you to
152 set an option given by <parameter>key</parameter> to the value
153 <parameter>value</parameter> for the connection.
154 For <function>ZOOM_connection_option_set</function>, the
155 value is assumed to be a 0-terminated string. Function
156 <function>ZOOM_connection_option_setl</function> specifies a
157 value of a certain size (len).
160 Functions <function>ZOOM_connection_option_get</function> and
161 <function>ZOOM_connection_option_getl</function> returns
162 the value for an option given by <parameter>key</parameter>.
164 <table id="zoom-connection-options" frame="top">
165 <title>ZOOM Connection Options</title>
167 <colspec colwidth="4*" colname="name"></colspec>
168 <colspec colwidth="7*" colname="description"></colspec>
169 <colspec colwidth="3*" colname="default"></colspec>
172 <entry>Option</entry>
173 <entry>Description</entry>
174 <entry>Default</entry>
179 implementationName</entry><entry>Name of Your client
180 </entry><entry>none</entry></row>
182 user</entry><entry>Authentication user name
183 </entry><entry>none</entry></row>
185 group</entry><entry>Authentication group name
186 </entry><entry>none</entry></row>
188 password</entry><entry>Authentication password.
189 </entry><entry>none</entry></row>
191 host</entry><entry>Target host. This setting is "read-only".
192 It's automatically set internally when connecting to a target.
193 </entry><entry>none</entry></row>
195 proxy</entry><entry>Proxy host
196 </entry><entry>none</entry></row>
198 async</entry><entry>If true (1) the connection operates in
199 asynchronous operation which means that all calls are non-blocking
201 <link linkend="zoom.events"><function>ZOOM_event</function></link>.
202 </entry><entry>0</entry></row>
204 maximumRecordSize</entry><entry> Maximum size of single record.
205 </entry><entry>1 MB</entry></row>
207 preferredMessageSize</entry><entry> Maximum size of multiple records.
208 </entry><entry>1 MB</entry></row>
210 lang</entry><entry> Language for negotiation.
211 </entry><entry>none</entry></row>
213 charset</entry><entry> Character set for negotiation.
214 </entry><entry>none</entry></row>
216 serverImplementationId</entry><entry>
217 Implementation ID of server. (The old targetImplementationId
218 option is also supported for the benefit of old applications.)
219 </entry><entry>none</entry></row>
221 targetImplementationName</entry><entry>
222 Implementation Name of server. (The old
223 targetImplementationName option is also supported for the
224 benefit of old applications.)
225 </entry><entry>none</entry></row>
227 serverImplementationVersion</entry><entry>
228 Implementation Version of server. (the old
229 targetImplementationVersion option is also supported for the
230 benefit of old applications.)
231 </entry><entry>none</entry></row>
233 databaseName</entry><entry>One or more database names
234 separated by character plus (<literal>+</literal>), which to
235 be used by subsequent search requests on this Connection.
236 </entry><entry>Default</entry></row>
238 piggyback</entry><entry>True (1) if piggyback should be
239 used in searches; false (0) if not.
240 </entry><entry>1</entry></row>
242 smallSetUpperBound</entry><entry>If hits is less than or equal to this
243 value, then target will return all records using small element set name
244 </entry><entry>0</entry></row>
246 largeSetLowerBound</entry><entry>If hits is greater than this
247 value, the target will return no records.
248 </entry><entry>1</entry></row>
250 mediumSetPresentNumber</entry><entry>This value represents
251 the number of records to be returned as part of a search when when
252 hits is less than or equal to large set lower bound and if hits
253 is greater than small set upper bound.
254 </entry><entry>0</entry></row>
256 smallSetElementSetName</entry><entry>
257 The element set name to be used for small result sets.
258 </entry><entry>none</entry></row>
260 mediumSetElementSetName</entry><entry>
261 The element set name to be for medium-sized result sets.
262 </entry><entry>none</entry></row>
264 init_opt_search, init_opt_present, init_opt_delSet, etc.</entry><entry>
265 After a successful Init, these options may be interrogated to
266 discover whether the server claims to support the specified
268 </entry><entry>none</entry></row>
270 sru_version</entry><entry>
271 SRU/SRW version. Should be <literal>1.1</literal>, or
272 <literal>1.2</literal>. This is , prior to connect, the version
273 to offer (highest version). And following connect (in fact
274 first operation), holds the negotiated version with the server
275 (same or lower version).
276 </entry><entry>1.2</entry></row>
281 If either option <literal>lang</literal> or <literal>charset</literal>
283 <ulink url="&url.z39.50.charneg;">
284 Character Set and Language Negotiation</ulink> is in effect.
287 int ZOOM_connection_error (ZOOM_connection c, const char **cp,
288 const char **addinfo);
289 int ZOOM_connection_error_x (ZOOM_connection c, const char **cp,
290 const char **addinfo, const char **dset);
293 Function <function>ZOOM_connection_error</function> checks for
294 errors for the last operation(s) performed. The function returns
295 zero if no errors occurred; non-zero otherwise indicating the error.
296 Pointers <parameter>cp</parameter> and <parameter>addinfo</parameter>
297 holds messages for the error and additional-info if passed as
298 non-<literal>NULL</literal>. Function
299 <function>ZOOM_connection_error_x</function> is an extended version
300 of <function>ZOOM_connection_error</function> that is capable of
301 returning name of diagnostic set in <parameter>dset</parameter>.
303 <sect2 id="zoom-connection-z39.50">
304 <title>Z39.50 Protocol behavior</title>
306 The calls <function>ZOOM_connection_new</function> and
307 <function>ZOOM_connection_connect</function> establishes a TCP/IP
308 connection and sends an Initialize Request to the target if
309 possible. In addition, the calls waits for an Initialize Response
310 from the target and the result is inspected (OK or rejected).
313 If <literal>proxy</literal> is set then the client will establish
314 a TCP/IP connection with the peer as specified by the
315 <literal>proxy</literal> host and the hostname as part of the
316 connect calls will be set as part of the Initialize Request.
317 The proxy server will then "forward" the PDU's transparently
318 to the target behind the proxy.
321 For the authentication parameters, if option <literal>user</literal>
322 is set and both options <literal>group</literal> and
323 <literal>pass</literal> are unset, then Open style
324 authentication is used (Version 2/3) in which case the username
325 is usually followed by a slash, then by a password.
326 If either <literal>group</literal>
327 or <literal>pass</literal> is set then idPass authentication
328 (Version 3 only) is used. If none of the options are set, no
329 authentication parameters are set as part of the Initialize Request
333 When option <literal>async</literal> is 1, it really means that
334 all network operations are postponed (and queued) until the
335 function <literal>ZOOM_event</literal> is invoked. When doing so
336 it doesn't make sense to check for errors after
337 <literal>ZOOM_connection_new</literal> is called since that
338 operation "connecting - and init" is still incomplete and the
339 API cannot tell the outcome (yet).
342 <sect2 id="zoom.sru.init.behavior">
343 <title>SRU Protocol behavior</title>
345 The SRU protocol doesn't feature an Inititialize Request, so
346 the connection phase merely establishes a TCP/IP connection
347 with the SOAP service.
349 <para>Most of the ZOOM connection options do not
350 affect SRU and they are ignored. However, future versions
351 of &yaz; might honor <literal>implementationName</literal> and
352 put that as part of User-Agent header for HTTP requests.
355 The <literal>charset</literal> is used in the Content-Type header
360 <sect1 id="zoom.query"><title>Queries</title>
362 Query objects represents queries.
365 ZOOM_query ZOOM_query_create(void);
367 void ZOOM_query_destroy(ZOOM_query q);
369 int ZOOM_query_prefix(ZOOM_query q, const char *str);
371 int ZOOM_query_cql(ZOOM_query s, const char *str);
373 int ZOOM_query_sortby(ZOOM_query q, const char *criteria);
376 Create query objects using <function>ZOOM_query_create</function>
377 and destroy them by calling <function>ZOOM_query_destroy</function>.
378 RPN-queries can be specified in <link linkend="PQF">PQF</link>
379 notation by using the
380 function <function>ZOOM_query_prefix</function>.
381 The <function>ZOOM_query_cql</function> specifies a CQL
382 query to be sent to the server/target.
383 More query types will be added in future versions of &yaz;, such as
384 <link linkend="CCL">CCL</link> to RPN-mapping, native CCL query,
385 etc. In addition to a search, a sort criteria may be set. Function
386 <function>ZOOM_query_sortby</function> specifies a
387 sort criteria using the same string notation for sort as offered by
388 the <link linkend="sortspec">YAZ client</link>.
390 <sect2 id="zoom.sort.behavior"><title>Protocol behavior</title>
392 The query object is just an interface for the member Query
393 in the SearchRequest. The sortby-function is an interface to the
394 sortSequence member of the SortRequest.
398 <sect1 id="zoom.resultsets"><title>Result sets</title>
400 The result set object is a container for records returned from
404 ZOOM_resultset ZOOM_connection_search(ZOOM_connection,
407 ZOOM_resultset ZOOM_connection_search_pqf(ZOOM_connection c,
410 void ZOOM_resultset_destroy(ZOOM_resultset r);
413 Function <function>ZOOM_connection_search</function> creates
414 a result set given a connection and query.
415 Destroy a result set by calling
416 <function>ZOOM_resultset_destroy</function>.
417 Simple clients may using PQF only may use function
418 <function>ZOOM_connection_search_pqf</function> in which case
419 creating query objects is not necessary.
422 void ZOOM_resultset_option_set (ZOOM_resultset r,
426 const char *ZOOM_resultset_option_get (ZOOM_resultset r,
429 size_t ZOOM_resultset_size (ZOOM_resultset r);
432 Functions <function>ZOOM_resultset_options_set</function> and
433 <function>ZOOM_resultset_get</function> sets and gets an option
434 for a result set similar to <function>ZOOM_connection_option_get</function>
435 and <function>ZOOM_connection_option_set</function>.
438 The number of hits also called result-count is returned by
439 function <function>ZOOM_resultset_size</function>.
441 <table id="zoom.resultset.options"
442 frame="top"><title>ZOOM Result set Options</title>
444 <colspec colwidth="4*" colname="name"></colspec>
445 <colspec colwidth="7*" colname="description"></colspec>
446 <colspec colwidth="2*" colname="default"></colspec>
449 <entry>Option</entry>
450 <entry>Description</entry>
451 <entry>Default</entry>
456 start</entry><entry>Offset of first record to be
457 retrieved from target. First record has offset 0 unlike the
458 protocol specifications where first record has position 1.
459 </entry><entry>0</entry></row>
461 count</entry><entry>Number of records to be retrieved.
462 </entry><entry>0</entry></row>
464 presentChunk</entry><entry>The number of records to be
465 requested from the server in each chunk (present requst). The
466 value 0 means to request all the records in a single chunk.
467 (The old <literal>step</literal>
468 option is also supported for the benefit of old applications.)
469 </entry><entry>0</entry></row>
471 elementSetName</entry><entry>Element-Set name of records.
472 Most targets should honor element set name <literal>B</literal>
473 and <literal>F</literal> for brief and full respectively.
474 </entry><entry>none</entry></row>
476 preferredRecordSyntax</entry><entry>Preferred Syntax, such as
477 <literal>USMARC</literal>, <literal>SUTRS</literal>, etc.
478 </entry><entry>none</entry></row>
480 schema</entry><entry>Schema for retrieval, such as
481 <literal>Gils-schema</literal>, <literal>Geo-schema</literal>, etc.
482 </entry><entry>none</entry></row>
484 setname</entry><entry>Name of Result Set (Result Set ID).
485 If this option isn't set, the ZOOM module will automatically
486 allocate a result set name.
487 </entry><entry>default</entry></row>
489 rpnCharset</entry><entry>Character set for RPN terms.
490 If this is set, ZOOM C will assume that the ZOOM application is
491 running UTF-8. Terms in RPN queries are then converted to the
492 rpnCharset. If this is unset, ZOOM C will not assume any encoding
493 of RPN terms and no conversion is performed.
494 </entry><entry>none</entry></row>
499 For servers that support Search Info report, the following
500 options may be read using <function>ZOOM_resultset_get</function>.
501 This detailed information is read after a successful search has
505 This information is a list of of items, where each item is
506 information about a term or subquery. All items in the list
508 <literal>SearchResult.</literal><replaceable>no</replaceable>
509 where no presents the item number (0=first, 1=second).
510 Read <literal>searchresult.size</literal> to determine the
513 <table id="zoom.search.info.report.options"
514 frame="top"><title>Search Info Report Options</title>
516 <colspec colwidth="4*" colname="name"></colspec>
517 <colspec colwidth="7*" colname="description"></colspec>
520 <entry>Option</entry>
521 <entry>Description</entry>
526 <entry>searchresult.size</entry>
528 number of search result entries. This option is-nonexistant
529 if no entries are returned by the server.
533 <entry>searchresult.<replaceable>no</replaceable>.id</entry>
534 <entry>sub query ID</entry>
537 <entry>searchresult.<replaceable>no</replaceable>.count</entry>
538 <entry>result count for item (number of hits)</entry>
541 <entry>searchresult.<replaceable>no</replaceable>.subquery.term</entry>
542 <entry>subquery term</entry>
546 searchresult.<replaceable>no</replaceable>.interpretation.term
548 <entry>interpretation term</entry>
552 searchresult.<replaceable>no</replaceable>.recommendation.term
554 <entry>recommendation term</entry>
559 <sect2 id="zoom.z3950.resultset.behavior">
560 <title>Z39.50 Protocol behavior</title>
562 The creation of a result set involves at least a SearchRequest
563 - SearchResponse protocol handshake. Following that, if a sort
564 criteria was specified as part of the query, a SortRequest -
565 SortResponse handshake takes place. Note that it is necessary to
566 perform sorting before any retrieval takes place, so no records will
567 be returned from the target as part of the SearchResponse because these
568 would be unsorted. Hence, piggyback is disabled when sort criteria
569 are set. Following Search - and a possible sort - Retrieval takes
570 place - as one or more Present Requests/Response pairs being
574 The API allows for two different modes for retrieval. A high level
575 mode which is somewhat more powerful and a low level one.
576 The low level is enabled when searching on a Connection object
577 for which the settings
578 <literal>smallSetUpperBound</literal>,
579 <literal>mediumSetPresentNumber</literal> and
580 <literal>largeSetLowerBound</literal> are set. The low level mode
581 thus allows you to precisely set how records are returned as part
582 of a search response as offered by the Z39.50 protocol.
583 Since the client may be retrieving records as part of the
584 search response, this mode doesn't work well if sorting is used.
587 The high-level mode allows you to fetch a range of records from
588 the result set with a given start offset. When you use this mode
589 the client will automatically use piggyback if that is possible
590 with the target and perform one or more present requests as needed.
591 Even if the target returns fewer records as part of a present response
592 because of a record size limit, etc. the client will repeat sending
593 present requests. As an example, if option <literal>start</literal>
594 is 0 (default) and <literal>count</literal> is 4, and
595 <literal>piggyback</literal> is 1 (default) and no sorting criteria
596 is specified, then the client will attempt to retrieve the 4
597 records as part the search response (using piggyback). On the other
598 hand, if either <literal>start</literal> is positive or if
599 a sorting criteria is set, or if <literal>piggyback</literal>
600 is 0, then the client will not perform piggyback but send Present
604 If either of the options <literal>mediumSetElementSetName</literal> and
605 <literal>smallSetElementSetName</literal> are unset, the value
606 of option <literal>elementSetName</literal> is used for piggyback
607 searches. This means that for the high-level mode you only have
608 to specify one elementSetName option rather than three.
611 <sect2 id="zoom.sru.resultset.behavior">
612 <title>SRU Protocol behavior</title>
614 Current version of &yaz; does not take advantage of a result set id
615 returned by the SRU server. Future versions might do, however.
616 Since, the ZOOM driver does not save result set IDs any
617 present (retrieval) is transformed to a SRU SearchRetrieveRequest
618 with same query but, possibly, different offsets.
621 Option <literal>schema</literal> specifies SRU schema
622 for retrieval. However, options <literal>elementSetName</literal> and
623 <literal>preferredRecordSyntax</literal> are ignored.
626 Options <literal>start</literal> and <literal>count</literal>
627 are supported by SRU.
628 The remaining options
629 <literal>piggyback</literal>,
630 <literal>smallSetUpperBound</literal>,
631 <literal>largeSetLowerBound</literal>,
632 <literal>mediumSetPresentNumber</literal>,
633 <literal>mediumSetElementSetName</literal>,
634 <literal>smallSetElementSetName</literal> are
638 SRU supports CQL queries, <emphasis>not</emphasis> PQF.
639 If PQF is used, however, the PQF query is transferred anyway
640 using non-standard element <literal>pQuery</literal> in
641 SRU SearchRetrieveRequest.
644 Unfortunately, SRU does not define a database setting. Hence,
645 <literal>databaseName</literal> is unsupported and ignored.
646 However, the path part in host parameter for functions
647 <function>ZOOM_connecton_new</function> and
648 <function>ZOOM_connection_connect</function> acts as a
649 database (at least for the &yaz; SRU server).
653 <sect1 id="zoom.records"><title>Records</title>
655 A record object is a retrieval record on the client side -
656 created from result sets.
659 void ZOOM_resultset_records(ZOOM_resultset r,
661 size_t start, size_t count);
662 ZOOM_record ZOOM_resultset_record(ZOOM_resultset s, size_t pos);
664 const char *ZOOM_record_get(ZOOM_record rec, const char *type,
667 int ZOOM_record_error(ZOOM_record rec, const char **msg,
668 const char **addinfo, const char **diagset);
670 ZOOM_record ZOOM_record_clone (ZOOM_record rec);
672 void ZOOM_record_destroy (ZOOM_record rec);
675 References to temporary records are returned by functions
676 <function>ZOOM_resultset_records</function> or
677 <function>ZOOM_resultset_record</function>.
680 If a persistent reference to a record is desired
681 <function>ZOOM_record_clone</function> should be used.
682 It returns a record reference that should be destroyed
683 by a call to <function>ZOOM_record_destroy</function>.
686 A single record is returned by function
687 <function>ZOOM_resultset_record</function> that takes a
688 position as argument. First record has position zero.
689 If no record could be obtained <literal>NULL</literal> is returned.
692 Error information for a record can be checked with
693 <function>ZOOM_record_error</function> which returns non-zero
694 (error code) if record is in error, called <emphasis>Surrogate
695 Diagnostics</emphasis> in Z39.50.
698 Function <function>ZOOM_resultset_records</function> retrieves
699 a number of records from a result set. Parameter <literal>start</literal>
700 and <literal>count</literal> specifies the range of records to
701 be returned. Upon completion array
702 <literal>recs[0], ..recs[count-1]</literal>
703 holds record objects for the records. The array of records
704 <literal>recs</literal> should be allocated prior the call
705 <function>ZOOM_resultset_records</function>. Note that for those
706 records that couldn't be retrieved from the target
707 <literal>recs[ ..]</literal> is set to <literal>NULL</literal>.
709 <para id="zoom.record.get">
710 In order to extract information about a single record,
711 <function>ZOOM_record_get</function> is provided. The
712 function returns a pointer to certain record information. The
713 nature (type) of the pointer depends on the parameter,
714 <parameter>type</parameter>.
717 The <parameter>type</parameter> is a string of the format:
720 <replaceable>form</replaceable>[; charset=<replaceable>from</replaceable>[,<replaceable>to</replaceable>]]
723 where <replaceable>form</replaceable> specifies the format of the
724 returned record, <replaceable>from</replaceable>
725 specifies the character set of the record in its original form
726 (as returned by the server), <replaceable>to</replaceable> specifies
727 the output (returned)
728 character set encoding.
729 If charset is not given, then no character set conversion takes place.
730 If <replaceable>to</replaceable> is omitted UTF-8 is assumed.
733 In addition, for certain types, the length
734 <literal>len</literal> passed will be set to the size in bytes of
735 the returned information.
738 The following are the supported values for <replaceable>form</replaceable>.
740 <varlistentry><term><literal>database</literal></term>
741 <listitem><para>Database of record is returned
742 as a C null-terminated string. Return type
743 <literal>const char *</literal>.
746 <varlistentry><term><literal>syntax</literal></term>
747 <listitem><para>The transfer syntax of the record is returned
748 as a C null-terminated string containing the symbolic name of
749 the record syntax, e.g. <literal>Usmarc</literal>. Return type
751 <literal>const char *</literal>.
754 <varlistentry><term><literal>schema</literal></term>
755 <listitem><para>The schema of the record is returned
756 as a C null-terminated string. Return type is
757 <literal>const char *</literal>.
760 <varlistentry><term><literal>render</literal></term>
761 <listitem><para>The record is returned in a display friendly
762 format. Upon completion buffer is returned
763 (type <literal>const char *</literal>) and length is stored in
764 <literal>*len</literal>.
767 <varlistentry><term><literal>raw</literal></term>
768 <listitem><para>The record is returned in the internal
769 YAZ specific format. For GRS-1, Explain, and others, the
770 raw data is returned as type
771 <literal>Z_External *</literal> which is just the type for
772 the member <literal>retrievalRecord</literal> in
773 type <literal>NamePlusRecord</literal>.
774 For SUTRS and octet aligned record (including all MARCs) the
775 octet buffer is returned and the length of the buffer.
778 <varlistentry><term><literal>xml</literal></term>
779 <listitem><para>The record is returned in XML if possible.
780 SRU and Z39.50 records with transfer syntax XML are
781 returned verbatim. MARC records are returned in
782 <ulink url="&url.marcxml;">
785 (converted from ISO2709 to MARCXML by YAZ).
786 GRS-1 and OPAC records are not supported for this form.
787 Upon completion, the XML buffer is returned
788 (type <literal>const char *</literal>) and length is stored in
789 <literal>*len</literal>.
792 <varlistentry><term><literal>opac</literal></term>
793 <listitem><para>OPAC for record is returned in XML.
800 <ulink url="&url.marc21;">MARC21</ulink>
802 <ulink url="&url.marc8;">MARC-8</ulink>
803 character set encoding.
804 An application that wishes to display in Latin-1 would use
806 render; charset=marc8,iso-8859-1
809 <sect2 id="zoom.z3950.record.behavior">
810 <title>Z39.50 Protocol behavior</title>
812 The functions <function>ZOOM_resultset_record</function> and
813 <function>ZOOM_resultset_records</function> inspects the client-side
814 record cache. Records not found in cache are fetched using
816 The functions may block (and perform network I/O) - even though option
817 <literal>async</literal> is 1, because they return records objects.
818 (and there's no way to return records objects without retrieving them!).
821 There is a trick, however, in the usage of function
822 <function>ZOOM_resultset_records</function> that allows for
823 delayed retrieval (and makes it non-blocking). By using
824 a null pointer for <parameter>recs</parameter> you're indicating
825 you're not interested in getting records objects
826 <emphasis>now</emphasis>.
829 <sect2 id="zoom.sru.record.behavior">
830 <title>SRU Protocol behavior</title>
832 The ZOOM driver for SRU treats records returned by a SRU server
833 as if they where Z39.50 records with transfer syntax XML and
834 no element set name or database name.
838 <sect1 id="zoom.scan"><title>Scan</title>
840 This section describes an interface for Scan. Scan is not an
841 official part of the ZOOM model yet. The result of a scan operation
842 is the <literal>ZOOM_scanset</literal> which is a set of terms
843 returned by a target.
847 The Scan interface is supported for both Z39.50 and SRU.
851 ZOOM_scanset ZOOM_connection_scan(ZOOM_connection c,
852 const char *startpqf);
854 ZOOM_scanset ZOOM_connection_scan1(ZOOM_connection c,
857 size_t ZOOM_scanset_size(ZOOM_scanset scan);
859 const char * ZOOM_scanset_term(ZOOM_scanset scan, size_t pos,
860 int *occ, size_t *len);
862 const char * ZOOM_scanset_display_term(ZOOM_scanset scan, size_t pos,
863 int *occ, size_t *len);
865 void ZOOM_scanset_destroy (ZOOM_scanset scan);
867 const char *ZOOM_scanset_option_get(ZOOM_scanset scan,
870 void ZOOM_scanset_option_set(ZOOM_scanset scan, const char *key,
874 The scan set is created by function
875 <function>ZOOM_connection_scan</function> which performs a scan
876 operation on the connection using the specified
877 <parameter>startpqf</parameter>.
878 If the operation was successful, the size of the scan set can be
879 retrieved by a call to <function>ZOOM_scanset_size</function>.
880 Like result sets, the items are numbered 0,..size-1.
881 To obtain information about a particular scan term, call function
882 <function>ZOOM_scanset_term</function>. This function takes
883 a scan set offset <literal>pos</literal> and returns a pointer
884 to a <emphasis>raw term</emphasis> or <literal>NULL</literal> if
886 If present, the <literal>occ</literal> and <literal>len</literal>
887 are set to the number of occurrences and the length
888 of the actual term respectively.
889 <function>ZOOM_scanset_display_term</function> is similar to
890 <function>ZOOM_scanset_term</function> except that it returns
891 the <emphasis>display term</emphasis> rather than the raw term.
892 In a few cases, the term is different from display term. Always
893 use the display term for display and the raw term for subsequent
894 scan operations (to get more terms, next scan result, etc).
897 A scan set may be freed by a call to function
898 <function>ZOOM_scanset_destroy</function>.
899 Functions <function>ZOOM_scanset_option_get</function> and
900 <function>ZOOM_scanset_option_set</function> retrieves and sets
901 an option respectively.
905 The <parameter>startpqf</parameter> is a subset of PQF, namely
906 the Attributes+Term part. Multiple <literal>@attr</literal> can
907 be used. For example to scan in title (complete) phrases:
909 @attr 1=4 @attr 6=2 "science o"
914 The <function>ZOOM_connecton_scan1</function> is a newer and
915 more generic alternative to <function>ZOOM_connection_scan</function>
916 which allows to use both CQL and PQF for Scan.
919 <table frame="top" id="zoom.scanset.options">
920 <title>ZOOM Scan Set Options</title>
922 <colspec colwidth="4*" colname="name"></colspec>
923 <colspec colwidth="7*" colname="description"></colspec>
924 <colspec colwidth="2*" colname="default"></colspec>
927 <entry>Option</entry>
928 <entry>Description</entry>
929 <entry>Default</entry>
934 number</entry><entry>Number of Scan Terms requested in next scan.
935 After scan it holds the actual number of terms returned.
936 </entry><entry>10</entry></row>
938 position</entry><entry>Preferred Position of term in response
939 in next scan; actual position after completion of scan.
940 </entry><entry>1</entry></row>
942 stepSize</entry><entry>Step Size
943 </entry><entry>0</entry></row>
945 scanStatus</entry><entry>An integer indicating the Scan Status
947 </entry><entry>0</entry></row>
949 rpnCharset</entry><entry>Character set for RPN terms.
950 If this is set, ZOOM C will assume that the ZOOM application is
951 running UTF-8. Terms in RPN queries are then converted to the
952 rpnCharset. If this is unset, ZOOM C will not assume any encoding
953 of RPN terms and no conversion is performed.
954 </entry><entry>none</entry></row>
960 <sect1 id="zoom.extendedservices"><title>Extended Services</title>
962 ZOOM offers an interface to a subset of the Z39.50 extended services
963 as well as a few privately defined ones:
968 Z39.50 Item Order (ILL).
969 See <xref linkend="zoom.item.order"/>.
974 Record Update. This allows a client to insert, modify or delete
976 See <xref linkend="zoom.record.update"/>.
981 Database Create. This a non-standard feature. Allows a client
982 to create a database.
983 See <xref linkend="zoom.database.create"/>.
988 Database Drop. This a non-standard feature. Allows a client
989 to delete/drop a database.
990 See <xref linkend="zoom.database.drop"/>.
995 Commit operation. This a non-standard feature. Allows a client
996 to commit operations.
997 See <xref linkend="zoom.commit"/>.
1000 <!-- all the ILL PDU options should go here too -->
1003 To create an extended service operation a <literal>ZOOM_package</literal>
1004 must be created. The operation is a five step operation. The
1005 package is created, package is configured by means of options,
1006 the package is send, result is inspected (by means of options),
1007 the package is destroyed.
1010 ZOOM_package ZOOM_connection_package(ZOOM_connection c,
1011 ZOOM_options options);
1013 const char *ZOOM_package_option_get(ZOOM_package p,
1015 void ZOOM_package_option_set(ZOOM_package p, const char *key,
1017 void ZOOM_package_send(ZOOM_package p, const char *type);
1019 void ZOOM_package_destroy(ZOOM_package p);
1022 The <function>ZOOM_connection_package</function> creates a
1023 package for the connection given using the options specified.
1026 Functions <function>ZOOM_package_option_get</function> and
1027 <function>ZOOM_package_option_set</function> gets and sets
1031 <function>ZOOM_package_send</function> sends
1032 the package the via connection specified in
1033 <function>ZOOM_connection_package</function>.
1034 The <parameter>type</parameter> specifies the actual extended service
1035 package type to be sent.
1038 <table frame="top" id="zoom.extendedservices.options">
1039 <title>Extended Service Common Options</title>
1041 <colspec colwidth="4*" colname="name"></colspec>
1042 <colspec colwidth="7*" colname="description"></colspec>
1043 <colspec colwidth="3*" colname="default"></colspec>
1046 <entry>Option</entry>
1047 <entry>Description</entry>
1048 <entry>Default</entry>
1053 <entry>package-name</entry>
1054 <entry>Extended Service Request package name. Must be specified
1055 as part of a request</entry>
1059 <entry>user-id</entry>
1060 <entry>User ID of Extended Service Package. Is a request option</entry>
1064 <entry>function</entry>
1066 Function of package - one of <literal>create</literal>,
1067 <literal>delete</literal>, <literal>modify</literal>. Is
1070 <entry><literal>create</literal></entry>
1073 <entry>waitAction</entry>
1075 Wait action for package. Possible values:
1076 <literal>wait</literal>, <literal>waitIfPossible</literal>,
1077 <literal>dontWait</literal> or <literal>dontReturnPackage</literal>.
1079 <entry><literal>waitIfPossible</literal></entry>
1082 <entry>targetReference</entry>
1084 Target Reference. This is part of the response as returned
1085 by the server. Read it after a successful operation.
1087 <entry><literal>none</literal></entry>
1093 <sect2 id="zoom.item.order"><title>Item Order</title>
1095 For Item Order, type must be set to <literal>itemorder</literal> in
1096 <function>ZOOM_package_send</function>.
1099 <table frame="top" id="zoom.item.order.options">
1100 <title>Item Order Options</title>
1102 <colspec colwidth="4*" colname="name"></colspec>
1103 <colspec colwidth="7*" colname="description"></colspec>
1104 <colspec colwidth="3*" colname="default"></colspec>
1107 <entry>Option</entry>
1108 <entry>Description</entry>
1109 <entry>Default</entry>
1114 <entry>contact-name</entry>
1115 <entry>ILL contact name</entry>
1119 <entry>contact-phone</entry>
1120 <entry>ILL contact phone</entry>
1124 <entry>contact-email</entry>
1125 <entry>ILL contact email</entry>
1129 <entry>itemorder-item</entry>
1130 <entry>Position for item (record) requested. An integer</entry>
1139 <sect2 id="zoom.record.update"><title>Record Update</title>
1141 For Record Update, type must be set to <literal>update</literal> in
1142 <function>ZOOM_package_send</function>.
1145 <table frame="top" id="zoom.record.update.options">
1146 <title>Record Update 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>action</entry>
1162 The update action. One of
1163 <literal>specialUpdate</literal>,
1164 <literal>recordInsert</literal>,
1165 <literal>recordReplace</literal>,
1166 <literal>recordDelete</literal>,
1167 <literal>elementUpdate</literal>.
1169 <entry><literal>specialUpdate (recordInsert for updateVersion=1 which does not support specialUpdate)</literal></entry>
1172 <entry>recordIdOpaque</entry>
1173 <entry>Opaque Record ID</entry>
1177 <entry>recordIdNumber</entry>
1178 <entry>Record ID number</entry>
1182 <entry>record</entry>
1183 <entry>The record itself</entry>
1187 <entry>syntax</entry>
1188 <entry>The record syntax (transfer syntax). Is a string that
1189 is a known record syntax.
1191 <entry>no syntax</entry>
1194 <entry>databaseName</entry>
1195 <entry>Database from connection object</entry>
1196 <entry>Default</entry>
1199 <entry>correlationInfo.note</entry>
1200 <entry>Correlation Info Note (string)</entry>
1204 <entry>correlationInfo.id</entry>
1205 <entry>Correlation Info ID (integer)</entry>
1209 <entry>elementSetName</entry>
1210 <entry>Element Set for Record</entry>
1214 <entry>updateVersion</entry>
1215 <entry>Record Update version which holds one of the values
1216 1, 2 or 3. Each version has a distinct OID:
1218 (<ulink url="&url.z39.50.extupdate1;">first version</ulink>) ,
1220 (second version) and
1221 1.2.840.10003.9.5.1.1
1222 (<ulink url="&url.z39.50.extupdate3;">third and
1223 newest version</ulink>).
1233 <sect2 id="zoom.database.create"><title>Database Create</title>
1235 For Database Create, type must be set to <literal>create</literal> in
1236 <function>ZOOM_package_send</function>.
1239 <table frame="top" id="zoom.database.create.options">
1240 <title>Database Create Options</title>
1242 <colspec colwidth="4*" colname="name"></colspec>
1243 <colspec colwidth="7*" colname="description"></colspec>
1244 <colspec colwidth="3*" colname="default"></colspec>
1247 <entry>Option</entry>
1248 <entry>Description</entry>
1249 <entry>Default</entry>
1254 <entry>databaseName</entry>
1255 <entry>Database from connection object</entry>
1256 <entry>Default</entry>
1263 <sect2 id="zoom.database.drop"><title>Database Drop</title>
1265 For Database Drop, type must be set to <literal>drop</literal> in
1266 <function>ZOOM_package_send</function>.
1269 <table frame="top" id="zoom.database.drop.options">
1270 <title>Database Drop Options</title>
1272 <colspec colwidth="4*" colname="name"></colspec>
1273 <colspec colwidth="7*" colname="description"></colspec>
1274 <colspec colwidth="3*" colname="default"></colspec>
1277 <entry>Option</entry>
1278 <entry>Description</entry>
1279 <entry>Default</entry>
1284 <entry>databaseName</entry>
1285 <entry>Database from connection object</entry>
1286 <entry>Default</entry>
1293 <sect2 id="zoom.commit"><title>Commit Operation</title>
1295 For Commit, type must be set to <literal>commit</literal> in
1296 <function>ZOOM_package_send</function>.
1300 <sect2 id="zoom.extended.services.behavior">
1301 <title>Protocol behavior</title>
1303 All the extended services are Z39.50-only.
1307 The database create, drop and commit services are privately defined
1309 Refer to <filename>esadmin.asn</filename> in YAZ for the ASN.1
1316 <sect1 id="zoom.options"><title>Options</title>
1318 Most &zoom; objects provide a way to specify options to change behavior.
1319 From an implementation point of view a set of options is just like
1320 an associative array / hash.
1323 ZOOM_options ZOOM_options_create (void);
1325 ZOOM_options ZOOM_options_create_with_parent (ZOOM_options parent);
1327 void ZOOM_options_destroy (ZOOM_options opt);
1330 const char *ZOOM_options_get (ZOOM_options opt, const char *name);
1332 void ZOOM_options_set (ZOOM_options opt, const char *name,
1336 typedef const char *(*ZOOM_options_callback)
1337 (void *handle, const char *name);
1339 ZOOM_options_callback
1340 ZOOM_options_set_callback (ZOOM_options opt,
1341 ZOOM_options_callback c,
1345 <sect1 id="zoom.events"><title>Events</title>
1347 If you're developing non-blocking applications, you have to deal
1351 int ZOOM_event (int no, ZOOM_connection *cs);
1354 The <function>ZOOM_event</function> executes pending events for
1355 a number of connections. Supply the number of connections in
1356 <literal>no</literal> and an array of connections in
1357 <literal>cs</literal> (<literal>cs[0] ... cs[no-1]</literal>).
1358 A pending event could be a sending a search, receiving a response,
1360 When an event has occurred for one of the connections, this function
1361 returns a positive integer <literal>n</literal> denoting that an event
1362 occurred for connection <literal>cs[n-1]</literal>.
1363 When no events are pending for the connections, a value of zero is
1365 To ensure that all outstanding requests are performed call this function
1366 repeatedly until zero is returned.
1369 If <function>ZOOM_event</function> returns and returns non-zero, the
1370 last event that occurred can be expected.
1373 int ZOOM_connection_last_event(ZOOM_connection cs);
1376 <function>ZOOM_connection_last_event</function> returns an event type
1377 (integer) for the last event.
1380 <table frame="top" id="zoom.event.ids">
1381 <title>ZOOM Event IDs</title>
1383 <colspec colwidth="4*" colname="name"></colspec>
1384 <colspec colwidth="7*" colname="description"></colspec>
1387 <entry>Event</entry>
1388 <entry>Description</entry>
1393 <entry>ZOOM_EVENT_NONE</entry>
1394 <entry>No event has occurred</entry>
1397 <entry>ZOOM_EVENT_CONNECT</entry>
1398 <entry>TCP/IP connect has initiated</entry>
1401 <entry>ZOOM_EVENT_SEND_DATA</entry>
1402 <entry>Data has been transmitted (sending)</entry>
1405 <entry>ZOOM_EVENT_RECV_DATA</entry>
1406 <entry>Data has been received)</entry>
1409 <entry>ZOOM_EVENT_TIMEOUT</entry>
1410 <entry>Timeout</entry>
1413 <entry>ZOOM_EVENT_UNKNOWN</entry>
1414 <entry>Unknown event</entry>
1417 <entry>ZOOM_EVENT_SEND_APDU</entry>
1418 <entry>An APDU has been transmitted (sending)</entry>
1421 <entry>ZOOM_EVENT_RECV_APDU</entry>
1422 <entry>An APDU has been received</entry>
1425 <entry>ZOOM_EVENT_RECV_RECORD</entry>
1426 <entry>A result-set record has been received</entry>
1429 <entry>ZOOM_EVENT_RECV_SEARCH</entry>
1430 <entry>A search result been received</entry>
1438 <!-- Keep this comment at the end of the file
1443 sgml-minimize-attributes:nil
1444 sgml-always-quote-attributes:t
1447 sgml-parent-document: "yaz.xml"
1448 sgml-local-catalogs: nil
1449 sgml-namecase-general:t