/*
* Initialize for xml parsing.
*/
void
pgxml_parser_init(void)
{
/* Set up error handling (we share the core's error handler) */
pg_xml_init();
/* Initialize libxml */
xmlInitParser();
xmlSubstituteEntitiesDefault(1);
xmlLoadExtDtdDefaultValue = 1;
}
/*
* Entry point for native XML support, shred XML document into tables and
* create indexes for future XQuery support
* @param
* @return
*/
Datum
build_xmlindex(PG_FUNCTION_ARGS)
{
xmltype *xmldata = NULL;
char *xmldataint = NULL;
text *xml_name = NULL;
char *xml_nameint;
int xmldatalen = -1;
int loader_return = 0; // false
int4 did;
#ifdef USE_LIBXML
elog(INFO, "build_xmlindex started");
xmldata = PG_GETARG_XML_P(0);
xmldataint = VARDATA(xmldata);
xmldatalen = VARSIZE(xmldata) - VARHDRSZ;
xmldataint[xmldatalen] = 0;
xml_name = PG_GETARG_TEXT_P(1);
xml_nameint = VARDATA(xml_name);
xml_nameint[VARSIZE(xml_name) - VARHDRSZ] = 0;
//initialize LibXML structures, if allready done -> do nothing
pg_xml_init();
xmlInitParser();
did = insert_xmldata_into_table(xmldataint, xml_nameint);
loader_return = xml_index_entry(xmldataint, xmldatalen, did);
elog(INFO, "build_xmlindex ended");
if (loader_return == XML_INDEX_LOADER_SUCCES)
{
PG_RETURN_BOOL(true);
} else
{
PG_RETURN_BOOL(false);
}
#else
NO_XML_SUPPORT();
PG_RETURN_BOOL (false);
#endif
}
/*
* Initialize for xml parsing.
*
* As with the underlying pg_xml_init function, calls to this MUST be followed
* by a PG_TRY block that guarantees that pg_xml_done is called.
*/
PgXmlErrorContext *
pgxml_parser_init(PgXmlStrictness strictness)
{
PgXmlErrorContext *xmlerrcxt;
/* Set up error handling (we share the core's error handler) */
xmlerrcxt = pg_xml_init(strictness);
/* Note: we're assuming an elog cannot be thrown by the following calls */
/* Initialize libxml */
xmlInitParser();
xmlSubstituteEntitiesDefault(1);
xmlLoadExtDtdDefaultValue = 1;
return xmlerrcxt;
}
/**
* Validation function take first argument as XML type, then check if is
* well formated. If so, do the same for DTD document. If both success, check
* XML document against DTD schema restrictions.
* @return true if pass, false otherwise
*/
Datum xmlvalidate_dtd(PG_FUNCTION_ARGS)
{
#ifdef USE_LIBXML
int ret = -1;
xmlValidCtxtPtr validctxt = NULL;
xmlDtdPtr dtd = NULL;
bool result = false;
text *data = NULL;
char *dtdstr = NULL;
xmltype *xmldata = NULL;
char *xmldataint = NULL;
xmlChar *xmldatastr = NULL;
int lenxml = -1; // length of xml data
xmlDocPtr doc = NULL;
// creating xmlChar * from internal xmltype of stored XML
xmldata = PG_GETARG_XML_P(0);
xmldataint = VARDATA(xmldata);
lenxml = VARSIZE(xmldata) - VARHDRSZ;
xmldatastr = (xmlChar *) palloc((lenxml + 1) * sizeof(xmlChar));
memcpy(xmldatastr, xmldataint, lenxml);
xmldatastr[lenxml] = '\0';
// creating xmlChar* from text representation of DTD
data = PG_GETARG_TEXT_P(1);
dtdstr = text_to_cstring(data);
//initialize LibXML structures, if allready done -> do nothing
pg_xml_init();
xmlInitParser();
doc = xmlReadMemory((const char *)xmldatastr, lenxml, "include.xml", NULL, 0);
if (doc == NULL) {
elog(ERROR, "Failed to parse XML document");
PG_RETURN_BOOL (false);
}
// create DTD from memory, must use XML_CHAR_ENCODING_NONE
dtd = xmlIOParseDTD(NULL,
xmlParserInputBufferCreateMem(dtdstr, strlen(dtdstr),
XML_CHAR_ENCODING_NONE),
XML_CHAR_ENCODING_NONE);
if (dtd == NULL)
{ // unable to create parser context
elog(ERROR, "Error with creating DTD schema, check if schema is valid");
PG_RETURN_BOOL (false);
}
validctxt = xmlNewValidCtxt();
if (validctxt == NULL)
{ // cant create validation context
elog(INFO ,"cant create validation context");
xmlFreeDtd(dtd);
PG_RETURN_BOOL (false);
}
ret = xmlValidateDtd(validctxt, doc, dtd);
if (ret == 0)
{
elog(INFO, "Validates");
result = true;
} else if (ret > 0)
{
elog(INFO, "Dont validates");
result = false;
} else
{
elog(INFO, "Validation generated an internal error");
result = false;
}
xmlFreeDtd(dtd);
xmlFreeValidCtxt(validctxt);
xmlFreeDoc(doc); // clean up document in memmory
xmlCleanupParser(); // clean up stream parser
PG_RETURN_BOOL (result);
#else
NO_XML_SUPPORT();
PG_RETURN_BOOL (false);
#endif
}
/**
* Validation function take first argument as XML type, then check if is
* well formated. If so, do the same for RNG document. If both success, check
* XML document against RNG schema restrictions.
* @return true if pass, false otherwise
*/
Datum
xmlvalidate_rng(PG_FUNCTION_ARGS)
{
#ifdef USE_LIBXML
text *data = NULL;
char *rng = NULL;
xmlChar *utf8rng = NULL;
xmltype *xmldata = NULL;
char *xmldataint = NULL;
xmlChar *xmldatastr = NULL;
bool result = false;
int lenxml = -1; // length of xml data
int lenrng = -1; // length of xsd data
xmlDocPtr doc = NULL;
int ret = -1;
xmlRelaxNGParserCtxtPtr ctxt = NULL;
xmlRelaxNGPtr schema = NULL;
xmlRelaxNGValidCtxtPtr validctxt = NULL;
// creating xmlChar * from internal xmltype of stored XML
xmldata = PG_GETARG_XML_P(0);
xmldataint = VARDATA(xmldata);
lenxml = VARSIZE(xmldata) - VARHDRSZ;
xmldatastr = (xmlChar *) palloc((lenxml + 1) * sizeof(xmlChar));
memcpy(xmldatastr, xmldataint, lenxml);
xmldatastr[lenxml] = '\0';
// creating xmlChar* from text representation of XSD
data = PG_GETARG_TEXT_P(1);
lenrng = VARSIZE(data) - VARHDRSZ;
rng = text_to_cstring(data);
//encode XML to internal representation with UTF-8, only one used in LibXML
utf8rng = pg_do_encoding_conversion((unsigned char*)rng,
lenrng,
GetDatabaseEncoding(),
PG_UTF8);
//initialize LibXML structures, if allready done -> do nothing
pg_xml_init();
xmlInitParser();
doc = xmlReadMemory((const char *)xmldatastr, lenxml, "include.xml", NULL, 0);
if (doc == NULL) {
elog(ERROR, "Failed to parse XML document");
PG_RETURN_BOOL (false);
}
ctxt = xmlRelaxNGNewMemParserCtxt(rng, lenrng);
if (ctxt == NULL)
{ // unable to create parser context
elog(ERROR, "Error with creating schema, check if RelaxNG schema is valid");
PG_RETURN_BOOL (false);
}
schema = xmlRelaxNGParse(ctxt); // parse schema
xmlRelaxNGFreeParserCtxt(ctxt); // realease parser context
validctxt = xmlRelaxNGNewValidCtxt(schema);
if (validctxt == NULL)
{ // cant create validation context
xmlRelaxNGFree(schema);
elog(ERROR, "Cant create validation context");
PG_RETURN_BOOL (false);
}
// set errors to SQL errors
xmlRelaxNGSetValidErrors(validctxt,
xml_error_handler,
NULL,
0);
ret = xmlRelaxNGValidateDoc(validctxt, doc);
if (ret == 0)
{
elog(INFO, "Validates");
result = true;
} else if (ret > 0)
{
elog(INFO, "Dont validates");
result = false;
} else
{
elog(INFO, "Validation generated an internal error");
result = false;
}
xmlRelaxNGFree(schema);
xmlRelaxNGFreeValidCtxt(validctxt);
xmlFreeDoc(doc); // clean up document in memmory
xmlCleanupParser(); // clean up stream parser
PG_RETURN_BOOL (result);
#else
NO_XML_SUPPORT();
PG_RETURN_BOOL (false);
#endif
}
