Header And Logo
|
#include "postgres.h"#include "access/htup_details.h"#include "executor/spi.h"#include "fmgr.h"#include "funcapi.h"#include "lib/stringinfo.h"#include "miscadmin.h"#include "utils/builtins.h"#include "utils/xml.h"#include <libxml/xpath.h>#include <libxml/tree.h>#include <libxml/xmlmemory.h>#include <libxml/xmlerror.h>#include <libxml/parserInternals.h>
Go to the source code of this file.
Data Structures | |
| struct | xpath_workspace |
Functions | |
| Datum | xml_is_well_formed (PG_FUNCTION_ARGS) |
| Datum | xml_encode_special_chars (PG_FUNCTION_ARGS) |
| Datum | xpath_nodeset (PG_FUNCTION_ARGS) |
| Datum | xpath_string (PG_FUNCTION_ARGS) |
| Datum | xpath_number (PG_FUNCTION_ARGS) |
| Datum | xpath_bool (PG_FUNCTION_ARGS) |
| Datum | xpath_list (PG_FUNCTION_ARGS) |
| Datum | xpath_table (PG_FUNCTION_ARGS) |
| PgXmlErrorContext * | pgxml_parser_init (PgXmlStrictness strictness) |
| static xmlChar * | pgxmlNodeSetToText (xmlNodeSetPtr nodeset, xmlChar *toptagname, xmlChar *septagname, xmlChar *plainsep) |
| static text * | pgxml_result_to_text (xmlXPathObjectPtr res, xmlChar *toptag, xmlChar *septag, xmlChar *plainsep) |
| static xmlChar * | pgxml_texttoxmlchar (text *textstring) |
| static xmlXPathObjectPtr | pgxml_xpath (text *document, xmlChar *xpath, xpath_workspace *workspace) |
| static void | cleanup_workspace (xpath_workspace *workspace) |
| PG_FUNCTION_INFO_V1 (xml_is_well_formed) | |
| PG_FUNCTION_INFO_V1 (xml_encode_special_chars) | |
| PG_FUNCTION_INFO_V1 (xpath_nodeset) | |
| PG_FUNCTION_INFO_V1 (xpath_list) | |
| PG_FUNCTION_INFO_V1 (xpath_string) | |
| PG_FUNCTION_INFO_V1 (xpath_number) | |
| PG_FUNCTION_INFO_V1 (xpath_bool) | |
| PG_FUNCTION_INFO_V1 (xpath_table) | |
Variables | |
| PG_MODULE_MAGIC | |
| static void cleanup_workspace | ( | xpath_workspace * | workspace | ) | [static] |
Definition at line 479 of file xpath.c.
References xpath_workspace::ctxt, xpath_workspace::doctree, and xpath_workspace::res.
Referenced by pgxml_xpath(), xpath_bool(), xpath_list(), xpath_nodeset(), xpath_number(), and xpath_string().
| PG_FUNCTION_INFO_V1 | ( | xml_encode_special_chars | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_nodeset | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_list | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_string | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_number | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_bool | ) |
| PG_FUNCTION_INFO_V1 | ( | xpath_table | ) |
| PG_FUNCTION_INFO_V1 | ( | xml_is_well_formed | ) |
| PgXmlErrorContext * pgxml_parser_init | ( | PgXmlStrictness | strictness | ) |
Definition at line 77 of file xpath.c.
References pg_xml_init().
Referenced by pgxml_xpath(), xml_is_well_formed(), xpath_table(), and xslt_process().
{
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;
}
| static text * pgxml_result_to_text | ( | xmlXPathObjectPtr | res, | |
| xmlChar * | toptag, | |||
| xmlChar * | septag, | |||
| xmlChar * | plainsep | |||
| ) | [static] |
Definition at line 493 of file xpath.c.
References cstring_to_text(), elog, NOTICE, NULL, and pgxmlNodeSetToText().
Referenced by xpath_list(), xpath_nodeset(), and xpath_string().
{
xmlChar *xpresstr;
text *xpres;
if (res == NULL)
return NULL;
switch (res->type)
{
case XPATH_NODESET:
xpresstr = pgxmlNodeSetToText(res->nodesetval,
toptag,
septag, plainsep);
break;
case XPATH_STRING:
xpresstr = xmlStrdup(res->stringval);
break;
default:
elog(NOTICE, "unsupported XQuery result: %d", res->type);
xpresstr = xmlStrdup((const xmlChar *) "<unsupported/>");
}
/* Now convert this result back to text */
xpres = cstring_to_text((char *) xpresstr);
/* Free various storage */
xmlFree(xpresstr);
return xpres;
}
| static xmlChar * pgxml_texttoxmlchar | ( | text * | textstring | ) | [static] |
Definition at line 247 of file xpath.c.
References text_to_cstring().
Referenced by xml_encode_special_chars(), xpath_bool(), xpath_list(), xpath_nodeset(), and xpath_number().
{
return (xmlChar *) text_to_cstring(textstring);
}
| static xmlXPathObjectPtr pgxml_xpath | ( | text * | document, | |
| xmlChar * | xpath, | |||
| xpath_workspace * | workspace | |||
| ) | [static] |
Definition at line 426 of file xpath.c.
References cleanup_workspace(), xpath_workspace::ctxt, xpath_workspace::doctree, ERROR, NULL, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, pg_xml_done(), PG_XML_STRICTNESS_LEGACY, pgxml_parser_init(), xpath_workspace::res, VARDATA, VARSIZE, and xml_ereport().
Referenced by xpath_bool(), xpath_list(), xpath_nodeset(), xpath_number(), and xpath_string().
{
int32 docsize = VARSIZE(document) - VARHDRSZ;
PgXmlErrorContext *xmlerrcxt;
xmlXPathCompExprPtr comppath;
workspace->doctree = NULL;
workspace->ctxt = NULL;
workspace->res = NULL;
xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
PG_TRY();
{
workspace->doctree = xmlParseMemory((char *) VARDATA(document),
docsize);
if (workspace->doctree != NULL)
{
workspace->ctxt = xmlXPathNewContext(workspace->doctree);
workspace->ctxt->node = xmlDocGetRootElement(workspace->doctree);
/* compile the path */
comppath = xmlXPathCompile(xpath);
if (comppath == NULL)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
"XPath Syntax Error");
/* Now evaluate the path expression. */
workspace->res = xmlXPathCompiledEval(comppath, workspace->ctxt);
xmlXPathFreeCompExpr(comppath);
}
}
PG_CATCH();
{
cleanup_workspace(workspace);
pg_xml_done(xmlerrcxt, true);
PG_RE_THROW();
}
PG_END_TRY();
if (workspace->res == NULL)
cleanup_workspace(workspace);
pg_xml_done(xmlerrcxt, false);
return workspace->res;
}
| static xmlChar * pgxmlNodeSetToText | ( | xmlNodeSetPtr | nodeset, | |
| xmlChar * | toptagname, | |||
| xmlChar * | septagname, | |||
| xmlChar * | plainsep | |||
| ) | [static] |
Definition at line 178 of file xpath.c.
Referenced by pgxml_result_to_text().
{
xmlBufferPtr buf;
xmlChar *result;
int i;
buf = xmlBufferCreate();
if ((toptagname != NULL) && (xmlStrlen(toptagname) > 0))
{
xmlBufferWriteChar(buf, "<");
xmlBufferWriteCHAR(buf, toptagname);
xmlBufferWriteChar(buf, ">");
}
if (nodeset != NULL)
{
for (i = 0; i < nodeset->nodeNr; i++)
{
if (plainsep != NULL)
{
xmlBufferWriteCHAR(buf,
xmlXPathCastNodeToString(nodeset->nodeTab[i]));
/* If this isn't the last entry, write the plain sep. */
if (i < (nodeset->nodeNr) - 1)
xmlBufferWriteChar(buf, (char *) plainsep);
}
else
{
if ((septagname != NULL) && (xmlStrlen(septagname) > 0))
{
xmlBufferWriteChar(buf, "<");
xmlBufferWriteCHAR(buf, septagname);
xmlBufferWriteChar(buf, ">");
}
xmlNodeDump(buf,
nodeset->nodeTab[i]->doc,
nodeset->nodeTab[i],
1, 0);
if ((septagname != NULL) && (xmlStrlen(septagname) > 0))
{
xmlBufferWriteChar(buf, "</");
xmlBufferWriteCHAR(buf, septagname);
xmlBufferWriteChar(buf, ">");
}
}
}
}
if ((toptagname != NULL) && (xmlStrlen(toptagname) > 0))
{
xmlBufferWriteChar(buf, "</");
xmlBufferWriteCHAR(buf, toptagname);
xmlBufferWriteChar(buf, ">");
}
result = xmlStrdup(buf->content);
xmlBufferFree(buf);
return result;
}
| Datum xml_encode_special_chars | ( | PG_FUNCTION_ARGS | ) |
Definition at line 146 of file xpath.c.
References cstring_to_text(), NULL, pfree(), PG_GETARG_TEXT_P, PG_RETURN_TEXT_P, and pgxml_texttoxmlchar().
{
text *tin = PG_GETARG_TEXT_P(0);
text *tout;
xmlChar *ts,
*tt;
ts = pgxml_texttoxmlchar(tin);
tt = xmlEncodeSpecialChars(NULL, ts);
pfree(ts);
tout = cstring_to_text((char *) tt);
xmlFree(tt);
PG_RETURN_TEXT_P(tout);
}
| Datum xml_is_well_formed | ( | PG_FUNCTION_ARGS | ) |
Definition at line 108 of file xpath.c.
{
text *t = PG_GETARG_TEXT_P(0); /* document buffer */
bool result = false;
int32 docsize = VARSIZE(t) - VARHDRSZ;
xmlDocPtr doctree;
PgXmlErrorContext *xmlerrcxt;
xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
PG_TRY();
{
doctree = xmlParseMemory((char *) VARDATA(t), docsize);
result = (doctree != NULL);
if (doctree != NULL)
xmlFreeDoc(doctree);
}
PG_CATCH();
{
pg_xml_done(xmlerrcxt, true);
PG_RE_THROW();
}
PG_END_TRY();
pg_xml_done(xmlerrcxt, false);
PG_RETURN_BOOL(result);
}
| Datum xpath_bool | ( | PG_FUNCTION_ARGS | ) |
Definition at line 396 of file xpath.c.
References cleanup_workspace(), NULL, pfree(), PG_GETARG_TEXT_P, PG_RETURN_BOOL, pgxml_texttoxmlchar(), and pgxml_xpath().
{
text *document = PG_GETARG_TEXT_P(0);
text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
int bRes;
xmlXPathObjectPtr res;
xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
res = pgxml_xpath(document, xpath, &workspace);
pfree(xpath);
if (res == NULL)
PG_RETURN_BOOL(false);
bRes = xmlXPathCastToBoolean(res);
cleanup_workspace(&workspace);
PG_RETURN_BOOL(bRes);
}
| Datum xpath_list | ( | PG_FUNCTION_ARGS | ) |
Definition at line 294 of file xpath.c.
References cleanup_workspace(), NULL, pfree(), PG_GETARG_TEXT_P, PG_RETURN_NULL, PG_RETURN_TEXT_P, pgxml_result_to_text(), pgxml_texttoxmlchar(), and pgxml_xpath().
{
text *document = PG_GETARG_TEXT_P(0);
text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *plainsep = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
xmlChar *xpath;
text *xpres;
xmlXPathObjectPtr res;
xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
res = pgxml_xpath(document, xpath, &workspace);
xpres = pgxml_result_to_text(res, NULL, NULL, plainsep);
cleanup_workspace(&workspace);
pfree(xpath);
if (xpres == NULL)
PG_RETURN_NULL();
PG_RETURN_TEXT_P(xpres);
}
| Datum xpath_nodeset | ( | PG_FUNCTION_ARGS | ) |
Definition at line 261 of file xpath.c.
References cleanup_workspace(), NULL, pfree(), PG_GETARG_TEXT_P, PG_RETURN_NULL, PG_RETURN_TEXT_P, pgxml_result_to_text(), pgxml_texttoxmlchar(), and pgxml_xpath().
{
text *document = PG_GETARG_TEXT_P(0);
text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *toptag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
xmlChar *septag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(3));
xmlChar *xpath;
text *xpres;
xmlXPathObjectPtr res;
xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
res = pgxml_xpath(document, xpath, &workspace);
xpres = pgxml_result_to_text(res, toptag, septag, NULL);
cleanup_workspace(&workspace);
pfree(xpath);
if (xpres == NULL)
PG_RETURN_NULL();
PG_RETURN_TEXT_P(xpres);
}
| Datum xpath_number | ( | PG_FUNCTION_ARGS | ) |
Definition at line 364 of file xpath.c.
References cleanup_workspace(), NULL, pfree(), PG_GETARG_TEXT_P, PG_RETURN_FLOAT4, PG_RETURN_NULL, pgxml_texttoxmlchar(), and pgxml_xpath().
{
text *document = PG_GETARG_TEXT_P(0);
text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
float4 fRes;
xmlXPathObjectPtr res;
xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
res = pgxml_xpath(document, xpath, &workspace);
pfree(xpath);
if (res == NULL)
PG_RETURN_NULL();
fRes = xmlXPathCastToNumber(res);
cleanup_workspace(&workspace);
if (xmlXPathIsNaN(fRes))
PG_RETURN_NULL();
PG_RETURN_FLOAT4(fRes);
}
| Datum xpath_string | ( | PG_FUNCTION_ARGS | ) |
Definition at line 323 of file xpath.c.
References cleanup_workspace(), NULL, palloc(), pfree(), PG_GETARG_TEXT_P, PG_RETURN_NULL, PG_RETURN_TEXT_P, pgxml_result_to_text(), pgxml_xpath(), VARDATA, and VARSIZE.
{
text *document = PG_GETARG_TEXT_P(0);
text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
int32 pathsize;
text *xpres;
xmlXPathObjectPtr res;
xpath_workspace workspace;
pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
/*
* We encapsulate the supplied path with "string()" = 8 chars + 1 for NUL
* at end
*/
/* We could try casting to string using the libxml function? */
xpath = (xmlChar *) palloc(pathsize + 9);
strncpy((char *) xpath, "string(", 7);
memcpy((char *) (xpath + 7), VARDATA(xpathsupp), pathsize);
xpath[pathsize + 7] = ')';
xpath[pathsize + 8] = '\0';
res = pgxml_xpath(document, xpath, &workspace);
xpres = pgxml_result_to_text(res, NULL, NULL, NULL);
cleanup_workspace(&workspace);
pfree(xpath);
if (xpres == NULL)
PG_RETURN_NULL();
PG_RETURN_TEXT_P(xpres);
}
| Datum xpath_table | ( | PG_FUNCTION_ARGS | ) |
Definition at line 537 of file xpath.c.
References ReturnSetInfo::allowedModes, appendStringInfo(), BuildTupleFromCStrings(), CreateTupleDescCopy(), ReturnSetInfo::econtext, ExprContext::ecxt_per_query_memory, elog, ereport, errcode(), errdetail(), errmsg(), ERROR, ReturnSetInfo::expectedDesc, heap_freetuple(), i, initStringInfo(), IsA, MemoryContextSwitchTo(), tupleDesc::natts, NOTICE, NULL, palloc(), pfree(), PG_CATCH, PG_END_TRY, PG_GETARG_TEXT_PP, PG_RE_THROW, PG_TRY, pg_xml_done(), PG_XML_STRICTNESS_LEGACY, pgxml_parser_init(), ReturnSetInfo::returnMode, ReturnSetInfo::setDesc, ReturnSetInfo::setResult, SFRM_Materialize, SFRM_Materialize_Random, SPI_connect(), SPI_exec(), SPI_finish(), SPI_getvalue(), SPI_OK_SELECT, SPI_processed, SPI_tuptable, text_to_cstring(), SPITupleTable::tupdesc, TupleDescGetAttInMetadata(), tuplestore_begin_heap(), tuplestore_donestoring, tuplestore_puttuple(), SPITupleTable::vals, values, work_mem, and xml_ereport().
{
/* Function parameters */
char *pkeyfield = text_to_cstring(PG_GETARG_TEXT_PP(0));
char *xmlfield = text_to_cstring(PG_GETARG_TEXT_PP(1));
char *relname = text_to_cstring(PG_GETARG_TEXT_PP(2));
char *xpathset = text_to_cstring(PG_GETARG_TEXT_PP(3));
char *condition = text_to_cstring(PG_GETARG_TEXT_PP(4));
/* SPI (input tuple) support */
SPITupleTable *tuptable;
HeapTuple spi_tuple;
TupleDesc spi_tupdesc;
/* Output tuple (tuplestore) support */
Tuplestorestate *tupstore = NULL;
TupleDesc ret_tupdesc;
HeapTuple ret_tuple;
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
AttInMetadata *attinmeta;
MemoryContext per_query_ctx;
MemoryContext oldcontext;
char **values;
xmlChar **xpaths;
char *pos;
const char *pathsep = "|";
int numpaths;
int ret;
int proc;
int i;
int j;
int rownr; /* For issuing multiple rows from one original
* document */
bool had_values; /* To determine end of nodeset results */
StringInfoData query_buf;
PgXmlErrorContext *xmlerrcxt;
volatile xmlDocPtr doctree = NULL;
/* We only have a valid tuple description in table function mode */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (rsinfo->expectedDesc == NULL)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table must be called as a table function")));
/*
* We want to materialise because it means that we don't have to carry
* libxml2 parser state between invocations of this function
*/
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table requires Materialize mode, but it is not "
"allowed in this context")));
/*
* The tuplestore must exist in a higher context than this function call
* (per_query_ctx is used)
*/
per_query_ctx = rsinfo->econtext->ecxt_per_query_memory;
oldcontext = MemoryContextSwitchTo(per_query_ctx);
/*
* Create the tuplestore - work_mem is the max in-memory size before a
* file is created on disk to hold it.
*/
tupstore =
tuplestore_begin_heap(rsinfo->allowedModes & SFRM_Materialize_Random,
false, work_mem);
MemoryContextSwitchTo(oldcontext);
/* get the requested return tuple description */
ret_tupdesc = CreateTupleDescCopy(rsinfo->expectedDesc);
/* must have at least one output column (for the pkey) */
if (ret_tupdesc->natts < 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("xpath_table must have at least one output column")));
/*
* At the moment we assume that the returned attributes make sense for the
* XPath specififed (i.e. we trust the caller). It's not fatal if they get
* it wrong - the input function for the column type will raise an error
* if the path result can't be converted into the correct binary
* representation.
*/
attinmeta = TupleDescGetAttInMetadata(ret_tupdesc);
/* Set return mode and allocate value space. */
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setDesc = ret_tupdesc;
values = (char **) palloc(ret_tupdesc->natts * sizeof(char *));
xpaths = (xmlChar **) palloc(ret_tupdesc->natts * sizeof(xmlChar *));
/*
* Split XPaths. xpathset is a writable CString.
*
* Note that we stop splitting once we've done all needed for tupdesc
*/
numpaths = 0;
pos = xpathset;
while (numpaths < (ret_tupdesc->natts - 1))
{
xpaths[numpaths++] = (xmlChar *) pos;
pos = strstr(pos, pathsep);
if (pos != NULL)
{
*pos = '\0';
pos++;
}
else
break;
}
/* Now build query */
initStringInfo(&query_buf);
/* Build initial sql statement */
appendStringInfo(&query_buf, "SELECT %s, %s FROM %s WHERE %s",
pkeyfield,
xmlfield,
relname,
condition);
if ((ret = SPI_connect()) < 0)
elog(ERROR, "xpath_table: SPI_connect returned %d", ret);
if ((ret = SPI_exec(query_buf.data, 0)) != SPI_OK_SELECT)
elog(ERROR, "xpath_table: SPI execution failed for query %s",
query_buf.data);
proc = SPI_processed;
/* elog(DEBUG1,"xpath_table: SPI returned %d rows",proc); */
tuptable = SPI_tuptable;
spi_tupdesc = tuptable->tupdesc;
/* Switch out of SPI context */
MemoryContextSwitchTo(oldcontext);
/*
* Check that SPI returned correct result. If you put a comma into one of
* the function parameters, this will catch it when the SPI query returns
* e.g. 3 columns.
*/
if (spi_tupdesc->natts != 2)
{
ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("expression returning multiple columns is not valid in parameter list"),
errdetail("Expected two columns in SPI result, got %d.", spi_tupdesc->natts)));
}
/*
* Setup the parser. This should happen after we are done evaluating the
* query, in case it calls functions that set up libxml differently.
*/
xmlerrcxt = pgxml_parser_init(PG_XML_STRICTNESS_LEGACY);
PG_TRY();
{
/* For each row i.e. document returned from SPI */
for (i = 0; i < proc; i++)
{
char *pkey;
char *xmldoc;
xmlXPathContextPtr ctxt;
xmlXPathObjectPtr res;
xmlChar *resstr;
xmlXPathCompExprPtr comppath;
/* Extract the row data as C Strings */
spi_tuple = tuptable->vals[i];
pkey = SPI_getvalue(spi_tuple, spi_tupdesc, 1);
xmldoc = SPI_getvalue(spi_tuple, spi_tupdesc, 2);
/*
* Clear the values array, so that not-well-formed documents
* return NULL in all columns. Note that this also means that
* spare columns will be NULL.
*/
for (j = 0; j < ret_tupdesc->natts; j++)
values[j] = NULL;
/* Insert primary key */
values[0] = pkey;
/* Parse the document */
if (xmldoc)
doctree = xmlParseMemory(xmldoc, strlen(xmldoc));
else /* treat NULL as not well-formed */
doctree = NULL;
if (doctree == NULL)
{
/* not well-formed, so output all-NULL tuple */
ret_tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, ret_tuple);
heap_freetuple(ret_tuple);
}
else
{
/* New loop here - we have to deal with nodeset results */
rownr = 0;
do
{
/* Now evaluate the set of xpaths. */
had_values = false;
for (j = 0; j < numpaths; j++)
{
ctxt = xmlXPathNewContext(doctree);
ctxt->node = xmlDocGetRootElement(doctree);
/* compile the path */
comppath = xmlXPathCompile(xpaths[j]);
if (comppath == NULL)
xml_ereport(xmlerrcxt, ERROR,
ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
"XPath Syntax Error");
/* Now evaluate the path expression. */
res = xmlXPathCompiledEval(comppath, ctxt);
xmlXPathFreeCompExpr(comppath);
if (res != NULL)
{
switch (res->type)
{
case XPATH_NODESET:
/* We see if this nodeset has enough nodes */
if (res->nodesetval != NULL &&
rownr < res->nodesetval->nodeNr)
{
resstr = xmlXPathCastNodeToString(res->nodesetval->nodeTab[rownr]);
had_values = true;
}
else
resstr = NULL;
break;
case XPATH_STRING:
resstr = xmlStrdup(res->stringval);
break;
default:
elog(NOTICE, "unsupported XQuery result: %d", res->type);
resstr = xmlStrdup((const xmlChar *) "<unsupported/>");
}
/*
* Insert this into the appropriate column in the
* result tuple.
*/
values[j + 1] = (char *) resstr;
}
xmlXPathFreeContext(ctxt);
}
/* Now add the tuple to the output, if there is one. */
if (had_values)
{
ret_tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, ret_tuple);
heap_freetuple(ret_tuple);
}
rownr++;
} while (had_values);
}
if (doctree != NULL)
xmlFreeDoc(doctree);
doctree = NULL;
if (pkey)
pfree(pkey);
if (xmldoc)
pfree(xmldoc);
}
}
PG_CATCH();
{
if (doctree != NULL)
xmlFreeDoc(doctree);
pg_xml_done(xmlerrcxt, true);
PG_RE_THROW();
}
PG_END_TRY();
if (doctree != NULL)
xmlFreeDoc(doctree);
pg_xml_done(xmlerrcxt, false);
tuplestore_donestoring(tupstore);
SPI_finish();
rsinfo->setResult = tupstore;
/*
* SFRM_Materialize mode expects us to return a NULL Datum. The actual
* tuples are in our tuplestore and passed back through rsinfo->setResult.
* rsinfo->setDesc is set to the tuple description that we actually used
* to build our tuples with, so the caller can verify we did what it was
* expecting.
*/
return (Datum) 0;
}
1.7.1