diff options
Diffstat (limited to 'src/backend/utils/adt/xml.c')
| -rw-r--r-- | src/backend/utils/adt/xml.c | 275 |
1 files changed, 209 insertions, 66 deletions
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index eaf5b4d550..702b9e3e9f 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -4,10 +4,10 @@ * XML data type support. * * - * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group + * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.98 2010/07/06 19:18:58 momjian Exp $ + * src/backend/utils/adt/xml.c * *------------------------------------------------------------------------- */ @@ -137,7 +137,7 @@ static void SPI_sql_row_to_xmlelement(int rownum, StringInfo result, errhint("You need to rebuild PostgreSQL using --with-libxml."))) -/* from SQL/XML:2003 section 4.7 */ +/* from SQL/XML:2008 section 4.9 */ #define NAMESPACE_XSD "http://www.w3.org/2001/XMLSchema" #define NAMESPACE_XSI "http://www.w3.org/2001/XMLSchema-instance" #define NAMESPACE_SQLXML "http://standards.iso.org/iso/9075/2003/sqlxml" @@ -1067,13 +1067,15 @@ parse_xml_decl(const xmlChar *str, size_t *lenp, if (xmlStrncmp(p, (xmlChar *) "'yes'", 5) == 0 || xmlStrncmp(p, (xmlChar *) "\"yes\"", 5) == 0) { - *standalone = 1; + if (standalone) + *standalone = 1; p += 5; } else if (xmlStrncmp(p, (xmlChar *) "'no'", 4) == 0 || xmlStrncmp(p, (xmlChar *) "\"no\"", 4) == 0) { - *standalone = 0; + if (standalone) + *standalone = 0; p += 4; } else @@ -1200,9 +1202,10 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, { /* * Note, that here we try to apply DTD defaults - * (XML_PARSE_DTDATTR) according to SQL/XML:10.16.7.d: 'Default - * values defined by internal DTD are applied'. As for external - * DTDs, we try to support them too, (see SQL/XML:10.16.7.e) + * (XML_PARSE_DTDATTR) according to SQL/XML:2008 GR 10.16.7.d: + * 'Default values defined by internal DTD are applied'. As for + * external DTDs, we try to support them too, (see SQL/XML:2008 GR + * 10.16.7.e) */ doc = xmlCtxtReadDoc(ctxt, utf8string, NULL, @@ -1217,8 +1220,8 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, { int res_code; size_t count; - xmlChar *version = NULL; - int standalone = -1; + xmlChar *version; + int standalone; res_code = parse_xml_decl(utf8string, &count, &version, NULL, &standalone); @@ -1490,7 +1493,7 @@ is_valid_xml_namechar(pg_wchar c) /* - * Map SQL identifier to XML name; see SQL/XML:2003 section 9.1. + * Map SQL identifier to XML name; see SQL/XML:2008 section 9.1. */ char * map_sql_identifier_to_xml_name(char *ident, bool fully_escaped, @@ -1570,7 +1573,7 @@ unicode_to_sqlchar(pg_wchar c) /* - * Map XML name to SQL identifier; see SQL/XML:2003 section 9.17. + * Map XML name to SQL identifier; see SQL/XML:2008 section 9.3. */ char * map_xml_name_to_sql_identifier(char *name) @@ -1603,21 +1606,19 @@ map_xml_name_to_sql_identifier(char *name) } /* - * Map SQL value to XML value; see SQL/XML:2003 section 9.16. + * Map SQL value to XML value; see SQL/XML:2008 section 9.8. * * When xml_escape_strings is true, then certain characters in string * values are replaced by entity references (< etc.), as specified - * in SQL/XML:2003 section 9.16 GR 8) ii). This is normally what is + * in SQL/XML:2008 section 9.8 GR 9) a) iii). This is normally what is * wanted. The false case is mainly useful when the resulting value * is used with xmlTextWriterWriteAttribute() to write out an - * attribute, because that function does the escaping itself. The SQL - * standard of 2003 is somewhat buggy in this regard, so we do our - * best to make sense. + * attribute, because that function does the escaping itself. */ char * map_sql_value_to_xml_value(Datum value, Oid type, bool xml_escape_strings) { - if (type_is_array(type)) + if (type_is_array_domain(type)) { ArrayType *array; Oid elmtype; @@ -1868,12 +1869,13 @@ _SPI_strdup(const char *s) /* * SQL to XML mapping functions * - * What follows below is intentionally organized so that you can read - * along in the SQL/XML:2003 standard. The functions are mostly split - * up and ordered they way the clauses lay out in the standards + * What follows below was at one point intentionally organized so that + * you can read along in the SQL/XML standard. The functions are + * mostly split up the way the clauses lay out in the standards * document, and the identifiers are also aligned with the standard - * text. (SQL/XML:2006 appears to be ordered differently, - * unfortunately.) + * text. Unfortunately, SQL/XML:2006 reordered the clauses + * differently than SQL/XML:2003, so the order below doesn't make much + * sense anymore. * * There are many things going on there: * @@ -1902,8 +1904,8 @@ _SPI_strdup(const char *s) /* - * Visibility of objects for XML mappings; see SQL/XML:2003 section - * 4.8.5. + * Visibility of objects for XML mappings; see SQL/XML:2008 section + * 4.10.8. */ /* @@ -1972,8 +1974,8 @@ database_get_xml_visible_tables(void) /* - * Map SQL table to XML and/or XML Schema document; see SQL/XML:2003 - * section 9.3. + * Map SQL table to XML and/or XML Schema document; see SQL/XML:2008 + * section 9.11. */ static StringInfo @@ -2269,8 +2271,8 @@ query_to_xml_and_xmlschema(PG_FUNCTION_ARGS) /* - * Map SQL schema to XML and/or XML Schema document; see SQL/XML:2003 - * section 9.4. + * Map SQL schema to XML and/or XML Schema document; see SQL/XML:2008 + * sections 9.13, 9.14. */ static StringInfo @@ -2446,8 +2448,8 @@ schema_to_xml_and_xmlschema(PG_FUNCTION_ARGS) /* - * Map SQL database to XML and/or XML Schema document; see SQL/XML:2003 - * section 9.5. + * Map SQL database to XML and/or XML Schema document; see SQL/XML:2008 + * sections 9.16, 9.17. */ static StringInfo @@ -2578,7 +2580,7 @@ database_to_xml_and_xmlschema(PG_FUNCTION_ARGS) /* - * Map a multi-part SQL name to an XML name; see SQL/XML:2003 section + * Map a multi-part SQL name to an XML name; see SQL/XML:2008 section * 9.2. */ static char * @@ -2606,11 +2608,11 @@ map_multipart_sql_identifier_to_xml_name(char *a, char *b, char *c, char *d) /* - * Map an SQL table to an XML Schema document; see SQL/XML:2003 - * section 9.3. + * Map an SQL table to an XML Schema document; see SQL/XML:2008 + * section 9.11. * - * Map an SQL table to XML Schema data types; see SQL/XML:2003 section - * 9.6. + * Map an SQL table to XML Schema data types; see SQL/XML:2008 section + * 9.9. */ static const char * map_sql_table_to_xmlschema(TupleDesc tupdesc, Oid relid, bool nulls, @@ -2712,8 +2714,8 @@ map_sql_table_to_xmlschema(TupleDesc tupdesc, Oid relid, bool nulls, /* - * Map an SQL schema to XML Schema data types; see SQL/XML section - * 9.7. + * Map an SQL schema to XML Schema data types; see SQL/XML:2008 + * section 9.12. */ static const char * map_sql_schema_to_xmlschema_types(Oid nspid, List *relid_list, bool nulls, @@ -2785,8 +2787,8 @@ map_sql_schema_to_xmlschema_types(Oid nspid, List *relid_list, bool nulls, /* - * Map an SQL catalog to XML Schema data types; see SQL/XML section - * 9.8. + * Map an SQL catalog to XML Schema data types; see SQL/XML:2008 + * section 9.15. */ static const char * map_sql_catalog_to_xmlschema_types(List *nspid_list, bool nulls, @@ -2843,7 +2845,7 @@ map_sql_catalog_to_xmlschema_types(List *nspid_list, bool nulls, /* - * Map an SQL data type to an XML name; see SQL/XML:2003 section 9.9. + * Map an SQL data type to an XML name; see SQL/XML:2008 section 9.4. */ static const char * map_sql_type_to_xml_name(Oid typeoid, int typmod) @@ -2948,7 +2950,7 @@ map_sql_type_to_xml_name(Oid typeoid, int typmod) /* * Map a collection of SQL data types to XML Schema data types; see - * SQL/XML:2002 section 9.10. + * SQL/XML:2008 section 9.7. */ static const char * map_sql_typecoll_to_xmlschema_types(List *tupdesc_list) @@ -2997,12 +2999,12 @@ map_sql_typecoll_to_xmlschema_types(List *tupdesc_list) /* - * Map an SQL data type to a named XML Schema data type; see SQL/XML - * sections 9.11 and 9.15. + * Map an SQL data type to a named XML Schema data type; see + * SQL/XML:2008 sections 9.5 and 9.6. * - * (The distinction between 9.11 and 9.15 is basically that 9.15 adds + * (The distinction between 9.5 and 9.6 is basically that 9.6 adds * a name attribute, which this function does. The name-less version - * 9.11 doesn't appear to be required anywhere.) + * 9.5 doesn't appear to be required anywhere.) */ static const char * map_sql_type_to_xmlschema_type(Oid typeoid, int typmod) @@ -3179,7 +3181,7 @@ map_sql_type_to_xmlschema_type(Oid typeoid, int typmod) /* * Map an SQL row to an XML element, taking the row from the active - * SPI cursor. See also SQL/XML:2003 section 9.12. + * SPI cursor. See also SQL/XML:2008 section 9.10. */ static void SPI_sql_row_to_xmlelement(int rownum, StringInfo result, char *tablename, @@ -3295,24 +3297,20 @@ xml_xmlnodetoxmltype(xmlNodePtr cur) /* - * Evaluate XPath expression and return array of XML values. + * Common code for xpath() and xmlexists() * - * As we have no support of XQuery sequences yet, this function seems - * to be the most useful one (array of XML functions plays a role of - * some kind of substitution for XQuery sequences). + * Evaluate XPath expression and return number of nodes in res_items + * and array of XML values in astate. * * It is up to the user to ensure that the XML passed is in fact * an XML document - XPath doesn't work easily on fragments without * a context node being known. */ -Datum -xpath(PG_FUNCTION_ARGS) -{ #ifdef USE_LIBXML - text *xpath_expr_text = PG_GETARG_TEXT_P(0); - xmltype *data = PG_GETARG_XML_P(1); - ArrayType *namespaces = PG_GETARG_ARRAYTYPE_P(2); - ArrayBuildState *astate = NULL; +static void +xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, + int *res_nitems, ArrayBuildState **astate) +{ xmlParserCtxtPtr ctxt = NULL; xmlDocPtr doc = NULL; xmlXPathContextPtr xpathctx = NULL; @@ -3324,7 +3322,6 @@ xpath(PG_FUNCTION_ARGS) xmlChar *string; xmlChar *xpath_expr; int i; - int res_nitems; int ndim; Datum *ns_names_uris; bool *ns_names_uris_nulls; @@ -3339,7 +3336,7 @@ xpath(PG_FUNCTION_ARGS) * ARRAY[ARRAY['myns', 'http://example.com'], ARRAY['myns2', * 'http://example2.com']]. */ - ndim = ARR_NDIM(namespaces); + ndim = namespaces ? ARR_NDIM(namespaces) : 0; if (ndim != 0) { int *dims; @@ -3439,6 +3436,13 @@ xpath(PG_FUNCTION_ARGS) xml_ereport(ERROR, ERRCODE_INTERNAL_ERROR, "invalid XPath expression"); + /* + * Version 2.6.27 introduces a function named + * xmlXPathCompiledEvalToBoolean, which would be enough for xmlexists, + * but we can derive the existence by whether any nodes are returned, + * thereby preventing a library version upgrade and keeping the code + * the same. + */ xpathobj = xmlXPathCompiledEval(xpathcomp, xpathctx); if (xpathobj == NULL) /* TODO: reason? */ xml_ereport(ERROR, ERRCODE_INTERNAL_ERROR, @@ -3446,21 +3450,22 @@ xpath(PG_FUNCTION_ARGS) /* return empty array in cases when nothing is found */ if (xpathobj->nodesetval == NULL) - res_nitems = 0; + *res_nitems = 0; else - res_nitems = xpathobj->nodesetval->nodeNr; + *res_nitems = xpathobj->nodesetval->nodeNr; - if (res_nitems) + if (*res_nitems && astate) { + *astate = NULL; for (i = 0; i < xpathobj->nodesetval->nodeNr; i++) { Datum elem; bool elemisnull = false; elem = PointerGetDatum(xml_xmlnodetoxmltype(xpathobj->nodesetval->nodeTab[i])); - astate = accumArrayResult(astate, elem, - elemisnull, XMLOID, - CurrentMemoryContext); + *astate = accumArrayResult(*astate, elem, + elemisnull, XMLOID, + CurrentMemoryContext); } } } @@ -3485,6 +3490,28 @@ xpath(PG_FUNCTION_ARGS) xmlXPathFreeContext(xpathctx); xmlFreeDoc(doc); xmlFreeParserCtxt(ctxt); +} +#endif /* USE_LIBXML */ + +/* + * Evaluate XPath expression and return array of XML values. + * + * As we have no support of XQuery sequences yet, this function seems + * to be the most useful one (array of XML functions plays a role of + * some kind of substitution for XQuery sequences). + */ +Datum +xpath(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *xpath_expr_text = PG_GETARG_TEXT_P(0); + xmltype *data = PG_GETARG_XML_P(1); + ArrayType *namespaces = PG_GETARG_ARRAYTYPE_P(2); + int res_nitems; + ArrayBuildState *astate; + + xpath_internal(xpath_expr_text, data, namespaces, + &res_nitems, &astate); if (res_nitems == 0) PG_RETURN_ARRAYTYPE_P(construct_empty_array(XMLOID)); @@ -3495,3 +3522,119 @@ xpath(PG_FUNCTION_ARGS) return 0; #endif } + +/* + * Determines if the node specified by the supplied XPath exists + * in a given XML document, returning a boolean. + */ +Datum +xmlexists(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *xpath_expr_text = PG_GETARG_TEXT_P(0); + xmltype *data = PG_GETARG_XML_P(1); + int res_nitems; + + xpath_internal(xpath_expr_text, data, NULL, + &res_nitems, NULL); + + PG_RETURN_BOOL(res_nitems > 0); +#else + NO_XML_SUPPORT(); + return 0; +#endif +} + +/* + * Determines if the node specified by the supplied XPath exists + * in a given XML document, returning a boolean. Differs from + * xmlexists as it supports namespaces and is not defined in SQL/XML. + */ +Datum +xpath_exists(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *xpath_expr_text = PG_GETARG_TEXT_P(0); + xmltype *data = PG_GETARG_XML_P(1); + ArrayType *namespaces = PG_GETARG_ARRAYTYPE_P(2); + int res_nitems; + + xpath_internal(xpath_expr_text, data, namespaces, + &res_nitems, NULL); + + PG_RETURN_BOOL(res_nitems > 0); +#else + NO_XML_SUPPORT(); + return 0; +#endif +} + +/* + * Functions for checking well-formed-ness + */ + +#ifdef USE_LIBXML +static bool +wellformed_xml(text *data, XmlOptionType xmloption_arg) +{ + bool result; + xmlDocPtr doc = NULL; + + /* We want to catch any exceptions and return false */ + PG_TRY(); + { + doc = xml_parse(data, xmloption_arg, true, GetDatabaseEncoding()); + result = true; + } + PG_CATCH(); + { + FlushErrorState(); + result = false; + } + PG_END_TRY(); + + if (doc) + xmlFreeDoc(doc); + + return result; +} +#endif + +Datum +xml_is_well_formed(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *data = PG_GETARG_TEXT_P(0); + + PG_RETURN_BOOL(wellformed_xml(data, xmloption)); +#else + NO_XML_SUPPORT(); + return 0; +#endif /* not USE_LIBXML */ +} + +Datum +xml_is_well_formed_document(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *data = PG_GETARG_TEXT_P(0); + + PG_RETURN_BOOL(wellformed_xml(data, XMLOPTION_DOCUMENT)); +#else + NO_XML_SUPPORT(); + return 0; +#endif /* not USE_LIBXML */ +} + +Datum +xml_is_well_formed_content(PG_FUNCTION_ARGS) +{ +#ifdef USE_LIBXML + text *data = PG_GETARG_TEXT_P(0); + + PG_RETURN_BOOL(wellformed_xml(data, XMLOPTION_CONTENT)); +#else + NO_XML_SUPPORT(); + return 0; +#endif /* not USE_LIBXML */ +} |