The first set of functions are straightforward XML parsing and XPath queries:

pgxml_parse(document) RETURNS bool

xml_valid(document) RETURNS bool

This parses the document text in its parameter and returns true if the

document is well-formed XML.

--SQL for XML parser

CREATE OR REPLACE FUNCTIONpgxml_parse(text) RETURNS bool

CREATE OR REPLACE FUNCTIONxml_valid(text) RETURNS bool

AS 'MODULE_PATHNAME' LANGUAGE 'c' WITH (isStrict);

CREATE OR REPLACE FUNCTION xpath_string(text,text) RETURNS text

staticxmlXPathObjectPtrpgxml_xpath(text*document,xmlChar*xpath);

Datumpgxml_parse(PG_FUNCTION_ARGS);

Datumxml_valid(PG_FUNCTION_ARGS);

Datumxpath_nodeset(PG_FUNCTION_ARGS);

Datumxpath_string(PG_FUNCTION_ARGS);

Datumxpath_number(PG_FUNCTION_ARGS);

PG_FUNCTION_INFO_V1(pgxml_parse);

PG_FUNCTION_INFO_V1(xml_valid);

pgxml_parse(PG_FUNCTION_ARGS)

xml_valid(PG_FUNCTION_ARGS)

{

xmlDocPtrdoctree;

text*t=PG_GETARG_TEXT_P(0);/* document buffer */

int32docsize=VARSIZE(t)-VARHDRSZ;

per_query_ctx=rsinfo->econtext->ecxt_per_query_memory;

oldcontext=MemoryContextSwitchTo(per_query_ctx);

tupstore=tuplestore_begin_heap(true, false,SortMem);

tupstore=tuplestore_begin_heap(true, false,work_mem);

MemoryContextSwitchTo(oldcontext);