X-Git-Url: http://git.indexdata.com/?p=yaz-moved-to-github.git;a=blobdiff_plain;f=doc%2Ftools.xml;h=5b09ab305811d81f111927be7cb4b24edbf3e70f;hp=985306ba2f08ec8535908830fbef254b6e9ebaf9;hb=aee1a87eeda33b4b049e9fc0a0a826b9c14018cc;hpb=4641562b204d07a8fca9e1fa94c86593766fa165 diff --git a/doc/tools.xml b/doc/tools.xml index 985306b..5b09ab3 100644 --- a/doc/tools.xml +++ b/doc/tools.xml @@ -1,4 +1,3 @@ - Supporting Tools @@ -129,11 +128,11 @@ query ::= top-set query-struct. - top-set ::= [ '@attrset' string ] + top-set ::= [ '@attrset' string ] query-struct ::= attr-spec | simple | complex | '@term' term-type query - attr-spec ::= '@attr' [ string ] string query-struct + attr-spec ::= '@attr' [ string ] string query-struct complex ::= operator query-struct query-struct. @@ -301,7 +300,8 @@ PQF queries - PQF queries using simple terms + + PQF queries using simple terms dylan @@ -310,7 +310,8 @@ - PQF boolean operators + + PQF boolean operators @or "dylan" "zimmerman" @@ -321,7 +322,8 @@ - PQF references to result sets + + PQF references to result sets @set Result-1 @@ -330,7 +332,8 @@ - Attributes for terms + + Attributes for terms @attr 1=4 computer @@ -345,7 +348,8 @@ - PQF Proximity queries + + PQF Proximity queries @prox 0 3 1 2 k 2 dylan zimmerman @@ -384,14 +388,16 @@ - PQF specification of search term + + PQF specification of search term type @term string "a UTF-8 string, maybe?" - PQF mixed queries + + PQF mixed queries @or @and bob dylan @set Result-1 @@ -428,23 +434,13 @@ symbolic language for expressing boolean query structures. - - The EUROPAGATE research project working under the Libraries programme - of the European Commission's DG XIII has, amongst other useful tools, - implemented a general-purpose CCL parser which produces an output - structure that can be trivially converted to the internal RPN - representation of &yaz; (The Z_RPNQuery structure). - Since the CCL utility - along with the rest of the software - produced by EUROPAGATE - is made freely available on a liberal - license, it is included as a supplement to &yaz;. - - - CCL Syntax + + CCL Syntax The CCL parser obeys the following grammar for the FIND argument. The syntax is annotated by in the lines prefixed by - ‐‐. + --. @@ -488,7 +484,8 @@ - CCL queries + + CCL queries The following queries are all valid: @@ -522,7 +519,8 @@ - CCL Qualifiers + + CCL Qualifiers Qualifiers are used to direct the search to a particular searchable @@ -544,7 +542,8 @@ lines in a CCL profile: qualifier specification, qualifier alias, comments and directives. - Qualifier specification + + Qualifier specification A qualifier specification is of the form: @@ -569,7 +568,8 @@ or c for completeness. The attributes for the special qualifier name term are used when no CCL qualifier is given in a query. - Common Bib-1 attributes +
+ Common Bib-1 attributes @@ -640,7 +640,7 @@
- Refer to the complete + Refer to or the complete list of Bib-1 attributes @@ -648,7 +648,8 @@ which are used in combination with certain types. The special combinations are: - Special attribute combos +
+ Special attribute combos @@ -734,7 +735,7 @@
- CCL profile + CCL profile Consider the following definition: @@ -779,7 +780,8 @@ - Qualifier alias + + Qualifier alias A qualifier alias is of the form: @@ -796,20 +798,23 @@ - Comments + + Comments Lines with white space or lines that begin with character # are treated as comments. - Directives + + Directives Directive specifications takes the form @directive value - CCL directives +
+ CCL directives @@ -873,7 +878,8 @@
- CCL API + + CCL API All public definitions can be found in the header file ccl.h. A profile identifier is of type @@ -936,15 +942,15 @@ struct ccl_rpn_node *ccl_find_str (CCL_bibset bibset, const char *str, - CQL + CQL CQL - Common Query Language - was defined for the - SRW protocol. + SRU protocol. In many ways CQL has a similar syntax to CCL. The objective of CQL is different. Where CCL aims to be an end-user language, CQL is the protocol - query language for SRW. + query language for SRU. @@ -969,7 +975,7 @@ struct ccl_rpn_node *ccl_find_str (CCL_bibset bibset, const char *str, The parser converts a valid CQL query to PQF, thus providing a - way to use CQL for both SRW/SRU servers and Z39.50 targets at the + way to use CQL for both SRU servers and Z39.50 targets at the same time. @@ -978,7 +984,7 @@ struct ccl_rpn_node *ccl_find_str (CCL_bibset bibset, const char *str, The parser converts CQL to XCQL. XCQL is an XML representation of CQL. - XCQL is part of the SRW specification. However, since SRU + XCQL is part of the SRU specification. However, since SRU supports CQL only, we don't expect XCQL to be widely used. Furthermore, CQL has the advantage over XCQL that it is easy to read. @@ -986,7 +992,7 @@ struct ccl_rpn_node *ccl_find_str (CCL_bibset bibset, const char *str, - CQL parsing + CQL parsing A CQL parser is represented by the CQL_parser handle. Its contents should be considered &yaz; internal (private). @@ -1032,7 +1038,7 @@ int cql_parser_stdio(CQL_parser cp, FILE *f); - CQL tree + CQL tree The the query string is valid, the CQL parser generates a tree representing the structure of the @@ -1136,12 +1142,12 @@ struct cql_node { - CQL to PQF conversion + CQL to PQF conversion Conversion to PQF (and Z39.50 RPN) is tricky by the fact that the resulting RPN depends on the Z39.50 target capabilities (combinations of supported attributes). - In addition, the CQL and SRW operates on index prefixes + In addition, the CQL and SRU operates on index prefixes (URI or strings), whereas the RPN uses Object Identifiers for attribute sets. @@ -1176,9 +1182,9 @@ int cql_transform_buf(cql_transform_t ct, If conversion failed, cql_transform_buf - returns a non-zero SRW error code; otherwise zero is returned + returns a non-zero SRU error code; otherwise zero is returned (conversion successful). The meanings of the numeric error - codes are listed in the SRW specifications at + codes are listed in the SRU specifications at @@ -1195,7 +1201,7 @@ int cql_transform_error(cql_transform_t ct, char **addinfop); context set that was not recognised. - The SRW error-codes may be translated into brief human-readable + The SRU error-codes may be translated into brief human-readable error messages using const char *cql_strerror(int code); @@ -1218,7 +1224,7 @@ int cql_transform_FILE(cql_transform_t ct, open FILE. - + Specification of CQL to RPN mappings The file supplied to functions @@ -1245,6 +1251,13 @@ int cql_transform_FILE(cql_transform_t ct, value the attribute value. + The character * (asterisk) has special meaning + when used in the RPN pattern. + Each occurrence of * is substituted with the + CQL matching name (index, relation, qualifier etc). + This facility can be used to copy a CQL name verbatim to the RPN result. + + The following CQL patterns are recognized: @@ -1265,6 +1278,11 @@ int cql_transform_FILE(cql_transform_t ct, http://www.loc.gov/zing/cql/cql-indexes/v1.0/. If this pattern is not defined, the mapping will fail. + + The pattern, + index.set.* + is used when no other index pattern is matched. + @@ -1367,28 +1385,41 @@ int cql_transform_FILE(cql_transform_t ct, + + + set + + + + This specification defines a default CQL context set for index names. + The value on the right hand side is the URI for the set. + + + + - CQL to RPN mapping file + + CQL to RPN mapping file This simple file defines two context sets, three indexes and three relations, a position pattern and a default structure. @@ -1423,8 +1454,51 @@ int cql_transform_FILE(cql_transform_t ct, + + CQL to RPN string attributes + + In this example we allow any index to be passed to RPN as + a use attribute. + + + + + The http://bogus/rpn context set is also the default + so we can make queries such as + + title = a + + which is converted to + + @attr 2=3 @attr 4=1 @attr 3=3 @attr 1=title "a" + + + + + CQL to RPN using Bath Profile + + The file etc/pqf.properties has mappings from + the Bath Profile and Dublin Core to RPN. + If YAZ is installed as a package it's usually located + in /usr/share/yaz/etc and part of the + development package, such as libyaz-dev. + + - CQL to XCQL conversion + CQL to XCQL conversion Conversion from CQL to XCQL is trivial and does not require a mapping to be defined. @@ -1455,293 +1529,178 @@ void cql_to_xml_stdio(struct cql_node *cn, FILE *f); The basic YAZ representation of an OID is an array of integers, - terminated with the value -1. The &odr; module provides two - utility-functions to create and copy this type of data elements: - - - - Odr_oid *odr_getoidbystr(ODR o, char *str); - - - - Creates an OID based on a string-based representation using dots (.) - to separate elements in the OID. - - - - Odr_oid *odr_oiddup(ODR odr, Odr_oid *o); - - - - Creates a copy of the OID referenced by the o - parameter. - Both functions take an &odr; stream as parameter. This stream is used to - allocate memory for the data elements, which is released on a - subsequent call to odr_reset() on that stream. - - - - The OID module provides a higher-level representation of the - family of object identifiers which describe the Z39.50 protocol and its - related objects. The definition of the module interface is given in - the oid.h file. - - - - The interface is mainly based on the oident structure. - The definition of this structure looks like this: - - - -typedef struct oident -{ - oid_proto proto; - oid_class oclass; - oid_value value; - int oidsuffix[OID_SIZE]; - char *desc; -} oident; - - - - The proto field takes one of the values - - - - PROTO_Z3950 - PROTO_GENERAL - - - - Use PROTO_Z3950 for Z39.50 Object Identifers, - PROTO_GENERAL for other types (such as - those associated with ILL). + terminated with the value -1. This integer is of type + Odr_oid. - - The oclass field takes one of the values + Fundamental OID operations and the type Odr_oid + are defined in yaz/oid_util.h. - - - CLASS_APPCTX - CLASS_ABSYN - CLASS_ATTSET - CLASS_TRANSYN - CLASS_DIAGSET - CLASS_RECSYN - CLASS_RESFORM - CLASS_ACCFORM - CLASS_EXTSERV - CLASS_USERINFO - CLASS_ELEMSPEC - CLASS_VARSET - CLASS_SCHEMA - CLASS_TAGSET - CLASS_GENERAL - - - corresponding to the OID classes defined by the Z39.50 standard. - - Finally, the value field takes one of the values + An OID can either be declared as a automatic variable or it can + allocated using the memory utilities or ODR/NMEM. It's + guaranteed that an OID can fit in OID_SIZE integers. - - - VAL_APDU - VAL_BER - VAL_BASIC_CTX - VAL_BIB1 - VAL_EXP1 - VAL_EXT1 - VAL_CCL1 - VAL_GILS - VAL_WAIS - VAL_STAS - VAL_DIAG1 - VAL_ISO2709 - VAL_UNIMARC - VAL_INTERMARC - VAL_CCF - VAL_USMARC - VAL_UKMARC - VAL_NORMARC - VAL_LIBRISMARC - VAL_DANMARC - VAL_FINMARC - VAL_MAB - VAL_CANMARC - VAL_SBN - VAL_PICAMARC - VAL_AUSMARC - VAL_IBERMARC - VAL_EXPLAIN - VAL_SUTRS - VAL_OPAC - VAL_SUMMARY - VAL_GRS0 - VAL_GRS1 - VAL_EXTENDED - VAL_RESOURCE1 - VAL_RESOURCE2 - VAL_PROMPT1 - VAL_DES1 - VAL_KRB1 - VAL_PRESSET - VAL_PQUERY - VAL_PCQUERY - VAL_ITEMORDER - VAL_DBUPDATE - VAL_EXPORTSPEC - VAL_EXPORTINV - VAL_NONE - VAL_SETM - VAL_SETG - VAL_VAR1 - VAL_ESPEC1 - - - - again, corresponding to the specific OIDs defined by the standard. - Refer to the - - Registry of Z39.50 Object Identifiers for the - whole list. - - - - The desc field contains a brief, mnemonic name for the OID in question. - - + Create OID on stack + + We can create an OID for the Bib-1 attribute set with: + + Odr_oid bib1[OID_SIZE]; + bib1[0] = 1; + bib1[1] = 2; + bib1[2] = 840; + bib1[3] = 10003; + bib1[4] = 3; + bib1[5] = 1; + bib1[6] = -1; + + + - The function + And OID may also be filled from a string-based representation using + dots (.). This is achieved by function + + int oid_dotstring_to_oid(const char *name, Odr_oid *oid); + + This functions returns 0 if name could be converted; -1 otherwise. - - - struct oident *oid_getentbyoid(int *o); - - - - takes as argument an OID, and returns a pointer to a static area - containing an oident structure. You typically use - this function when you receive a PDU containing an OID, and you wish - to branch out depending on the specific OID value. + Using oid_oiddotstring_to_oid + + We can fill the Bib-1 attribute set OID easier with: + + Odr_oid bib1[OID_SIZE]; + oid_oiddotstring_to_oid("1.2.840.10003.3.1", bib1); + - + - The function - - + We can also allocate an OID dynamically on a ODR stream with: - int *oid_ent_to_oid(struct oident *ent, int *dst); + Odr_oid *odr_getoidbystr(ODR o, const char *str); - - - Takes as argument an oident structure - in which - the proto, oclass/, and - value fields are assumed to be set correctly - - and returns a pointer to a the buffer as given by dst - containing the base - representation of the corresponding OID. The function returns - NULL and the array dst is unchanged if a mapping couldn't place. - The array dst should be at least of size - OID_SIZE. + This creates an OID from string-based representation using dots. + This function take an &odr; stream as parameter. This stream is used to + allocate memory for the data elements, which is released on a + subsequent call to odr_reset() on that stream. - - The oid_ent_to_oid() function can be used whenever - you need to prepare a PDU containing one or more OIDs. The separation of - the protocol element from the remainder of the - OID-description makes it simple to write applications that can - communicate with either Z39.50 or OSI SR-based applications. - + Using odr_getoidbystr + + We can create a OID for the Bib-1 attribute set with: + + Odr_oid *bib1 = odr_getoidbystr(odr, "1.2.840.10003.3.1"); + + + The function - - - - oid_value oid_getvalbyname(const char *name); - - - - takes as argument a mnemonic OID name, and returns the - /value field of the first entry in the database that - contains the given name in its desc field. + + char *oid_oid_to_dotstring(const Odr_oid *oid, char *oidbuf) + + does the reverse of oid_oiddotstring_to_oid. It + converts an OID to the string-based representation using dots. + The supplied char buffer oidbuf holds the resulting + string and must be at least OID_STR_MAX in size. - Three utility functions are provided for translating OIDs' - symbolic names (e.g. Usmarc into OID structures - (int arrays) and strings containing the OID in dotted notation - (e.g. 1.2.840.10003.9.5.1). They are: + OIDs can be copied with oid_oidcpy which takes + two OID lists as arguments. Alternativly, an OID copy can be allocated + on a ODR stream with: + + Odr_oid *odr_oiddup(ODR odr, const Odr_oid *o); + - - - int *oid_name_to_oid(oid_class oclass, const char *name, int *oid); - char *oid_to_dotstring(const int *oid, char *oidbuf); - char *oid_name_to_dotstring(oid_class oclass, const char *name, char *oidbuf); - - - - oid_name_to_oid() - translates the specified symbolic name, - interpreted as being of class oclass. (The - class must be specified as many symbolic names exist within - multiple classes - for example, Zthes is the - symbolic name of an attribute set, a schema and a tag-set.) The - sequence of integers representing the OID is written into the - area oid provided by the caller; it is the - caller's responsibility to ensure that this area is large enough - to contain the translated OID. As a convenience, the address of - the buffer (i.e. the value of oid) is - returned. - - - oid_to_dotstring() - Translates the int-array oid into a dotted - string which is written into the area oidbuf - supplied by the caller; it is the caller's responsibility to - ensure that this area is large enough. The address of the buffer - is returned. - - - oid_name_to_dotstring() - combines the previous two functions to derive a dotted string - representing the OID specified by oclass and - name, writing it into the buffer passed as - oidbuf and returning its address. - - + - Finally, the module provides the following utility functions, whose - meaning should be obvious: + OIDs can be compared with oid_oidcmp which returns + zero if the two OIDs provided are identical; non-zero otherwise. + + OID database + + From YAZ version 3 and later, the oident system has been replaced + by an OID database. OID database is a misnomer .. the old odient + system was also a database. + + + The OID database is really just a map between named Object Identifiers + (string) and their OID raw equivalents. Most operations either + convert from string to OID or other way around. + + + Unfortunately, whenever we supply a string we must also specify the + OID class. The class is necessary because some + strings correspond to multiple OIDs. An example of such a string is + Bib-1 which may either be an attribute-set + or a diagnostic-set. + + + Applications using the YAZ database should include + yaz/oid_db.h. + + + A YAZ database handle is of type yaz_oid_db_t. + Actually that's a pointer. You need not think deal with that. + YAZ has a built-in database which can be considered "constant" for + most purposes. + We can get hold that by using function yaz_oid_std. + + + All functions with prefix yaz_string_to_oid + converts from class + string to OID. We have variants of this + operation due to different memory allocation strategies. + + + All functions with prefix + yaz_oid_to_string converts from OID to string + + class. + - - void oid_oidcpy(int *t, int *s); - void oid_oidcat(int *t, int *s); - int oid_oidcmp(int *o1, int *o2); - int oid_oidlen(int *o); - + Create OID with YAZ DB + + We can create an OID for the Bib-1 attribute set on the ODR stream + odr with: + + Odr_oid *bib1 = + yaz_string_to_oid_odr(yaz_oid_std(), CLASS_ATTSET, "Bib-1", odr); + + This is more complex than using odr_getoidbystr. + You would only use yaz_string_to_oid_odr when the + string (here Bib-1) is supplied by a user or configuration. + + - + + Standard OIDs + + + All the object identifers in the standard OID database as returned + by yaz_oid_std can referenced directly in a + program as a constant OID. + Each constant OID is prefixed with yaz_oid_ - + followed by OID class (lowercase) - then by OID name (normalized and + lowercase). + - The OID module has been criticized - and perhaps rightly so - - for needlessly abstracting the - representation of OIDs. Other toolkits use a simple - string-representation of OIDs with good results. In practice, we have - found the interface comfortable and quick to work with, and it is a - simple matter (for what it's worth) to create applications compatible - with both ISO SR and Z39.50. Finally, the use of the - /oident database is by no means mandatory. - You can easily create your own system for representing OIDs, as long - as it is compatible with the low-level integer-array representation - of the ODR module. + See for list of all object identifiers + built into YAZ. + These are declared in yaz/oid_std.h but are + included by yaz/oid_db.h as well. - + Use a built-in OID + + We can allocate our own OID filled with the constant OID for + Bib-1 with: + + Odr_oid *bib1 = odr_oiddup(o, yaz_oid_attset_bib1); + + + + - Nibble Memory @@ -1950,7 +1909,7 @@ typedef struct oident - MARC + MARC YAZ provides a fast utility that decodes MARC records and @@ -2012,7 +1971,7 @@ typedef struct oident - YAZ_MARC_MARXML + YAZ_MARC_MARCXML The resulting record is converted to MARCXML. @@ -2038,7 +1997,7 @@ typedef struct oident stores the resulting record in a WRBUF handle (WRBUF is a simple string type). - + Display of MARC record The followint program snippet illustrates how the MARC API may @@ -2061,6 +2020,270 @@ typedef struct oident + + Retrieval Facility + + YAZ version 2.1.20 or later includes a Retrieval facility tool + which allows a SRU/Z39.50 to describe itself and perform record + conversions. The idea is the following: + + + + + An SRU/Z39.50 client sends a retrieval request which includes + a combination of the following parameters: syntax (format), + schema (or element set name). + + + + + + The retrieval facility is invoked with parameters in a + server/proxy. The retrieval facility matches the parameters a set of + "supported" retrieval types. + If there is no match, the retrieval signals an error + (syntax and / or schema not supported). + + + + + + For a successful match, the backend is invoked with the same + or altered retrieval parameters (syntax, schema). If + a record is received from the backend, it is converted to the + frontend name / syntax. + + + + + + The resulting record is sent back the client and tagged with + the frontend syntax / schema. + + + + + + + The Retrieval facility is driven by an XML configuration. The + configuration is neither Z39.50 ZeeRex or SRU ZeeRex. But it + should be easy to generate both of them from the XML configuration. + (unfortunately the two versions + of ZeeRex differ substantially in this regard). + + + Retrieval XML format + + All elements should be covered by namespace + http://indexdata.com/yaz . + The root element node must be retrievalinfo. + + + The retrievalinfo must include one or + more retrieval elements. Each + retrieval defines specific combination of + syntax, name and identifier supported by this retrieval service. + + + The retrieval element may include any of the + following attributes: + + syntax (REQUIRED) + + + Defines the record syntax. Possible values is any + of the names defined in YAZ' OID database or a raw + OID in (n.n ... n). + + + + name (OPTIONAL) + + + Defines the name of the retrieval format. This can be + any string. For SRU, the value, is equivalent to schema (short-hand); + for Z39.50 it's equivalent to simple element set name. + For YAZ 3.0.24 and later this name may be specified as a glob + expression with operators + * and ?. + + + + identifier (OPTIONAL) + + + Defines the URI schema name of the retrieval format. This can be + any string. For SRU, the value, is equivalent to URI schema. + For Z39.50, there is no equivalent. + + + + + + + The retrieval may include one + backend element. If a backend + element is given, it specifies how the records are retrieved by + some backend and how the records are converted from the backend to + the "frontend". + + + The attributes, name and syntax + may be specified for the backend element. These + semantics of these attributes is equivalent to those for the + retrieval. However, these values are passed to + the "backend". + + + The backend element may includes one or more + conversion instructions (as children elements). The supported + conversions are: + + marc + + + The marc element specifies a conversion + to - and from ISO2709 encoded MARC and + &acro.marcxml;/MarcXchange. + The following attributes may be specified: + + + inputformat (REQUIRED) + + + Format of input. Supported values are + marc (for ISO2709); and xml + for MARCXML/MarcXchange. + + + + + outputformat (REQUIRED) + + + Format of output. Supported values are + line (MARC line format); + marcxml (for MARCXML), + marc (ISO2709), + marcxhcange (for MarcXchange). + + + + + inputcharset (OPTIONAL) + + + Encoding of input. For XML input formats, this need not + be given, but for ISO2709 based inputformats, this should + be set to the encoding used. For MARC21 records, a common + inputcharset value would be marc-8. + + + + + outputcharset (OPTIONAL) + + + Encoding of output. If outputformat is XML based, it is + strongly recommened to use utf-8. + + + + + + + + + xslt + + + The xslt element specifies a conversion + via &acro.xslt;. The following attributes may be specified: + + + stylesheet (REQUIRED) + + + Stylesheet file. + + + + + + + + + + + + + Retrieval Facility Examples + + MARC21 backend + + A typical way to use the retrieval facility is to enable XML + for servers that only supports ISO2709 encoded MARC21 records. + + + + + + + + + + + + + + + + +]]> + + + This means that our frontend supports: + + + + MARC21 F(ull) records. + + + + + MARC21 B(rief) records. + + + + + + MARCXML records. + + + + + + Dublin core records. + + + + + + + + API + + It should be easy to use the retrieval systems from applications. Refer + to the headers + yaz/retrieval.h and + yaz/record_conv.h. + + +