diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 2f243bd1913c3134d17cb040f40d7e2857b5d7fb..5f5654c232aeaca4e0fa92345b680b7c5444ec0a 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.49 2007/10/13 20:46:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.50 2007/11/05 22:23:07 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -73,6 +73,10 @@
#include "utils/xml.h"
+/* GUC variables */
+XmlBinaryType xmlbinary;
+XmlOptionType xmloption;
+
#ifdef USE_LIBXML
static StringInfo xml_err_buf = NULL;
@@ -104,11 +108,6 @@ static const char * map_sql_typecoll_to_xmlschema_types(List *tupdesc_list);
static const char * map_sql_type_to_xmlschema_type(Oid typeoid, int typmod);
static void SPI_sql_row_to_xmlelement(int rownum, StringInfo result, char *tablename, bool nulls, bool tableforest, const char *targetns, bool top_level);
-
-XmlBinaryType xmlbinary;
-XmlOptionType xmloption;
-
-
#define NO_XML_SUPPORT() \
ereport(ERROR, \
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), \
@@ -217,7 +216,8 @@ xml_out_internal(xmltype *x, pg_enc target_encoding)
}
xml_ereport_by_code(WARNING, ERRCODE_INTERNAL_ERROR,
- "could not parse XML declaration in stored value", res_code);
+ "could not parse XML declaration in stored value",
+ res_code);
#endif
return str;
}
@@ -540,45 +540,84 @@ xmlelement(XmlExprState *xmlExpr, ExprContext *econtext)
{
#ifdef USE_LIBXML
XmlExpr *xexpr = (XmlExpr *) xmlExpr->xprstate.expr;
+ xmltype *result;
+ List *named_arg_strings;
+ List *arg_strings;
int i;
ListCell *arg;
ListCell *narg;
- bool isnull;
- xmltype *result;
- Datum value;
- char *str;
-
xmlBufferPtr buf;
xmlTextWriterPtr writer;
- buf = xmlBufferCreate();
- writer = xmlNewTextWriterMemory(buf, 0);
-
- xmlTextWriterStartElement(writer, (xmlChar *) xexpr->name);
-
+ /*
+ * We first evaluate all the arguments, then start up libxml and
+ * create the result. This avoids issues if one of the arguments
+ * involves a call to some other function or subsystem that wants to use
+ * libxml on its own terms.
+ */
+ named_arg_strings = NIL;
i = 0;
- forboth(arg, xmlExpr->named_args, narg, xexpr->arg_names)
+ foreach(arg, xmlExpr->named_args)
{
ExprState *e = (ExprState *) lfirst(arg);
- char *argname = strVal(lfirst(narg));
+ Datum value;
+ bool isnull;
+ char *str;
value = ExecEvalExpr(e, econtext, &isnull, NULL);
- if (!isnull)
- {
+ if (isnull)
+ str = NULL;
+ else
str = OutputFunctionCall(&xmlExpr->named_outfuncs[i], value);
- xmlTextWriterWriteAttribute(writer, (xmlChar *) argname, (xmlChar *) str);
- pfree(str);
- }
+ named_arg_strings = lappend(named_arg_strings, str);
i++;
}
+ arg_strings = NIL;
foreach(arg, xmlExpr->args)
{
ExprState *e = (ExprState *) lfirst(arg);
+ Datum value;
+ bool isnull;
+ char *str;
value = ExecEvalExpr(e, econtext, &isnull, NULL);
+ /* here we can just forget NULL elements immediately */
if (!isnull)
- xmlTextWriterWriteRaw(writer, (xmlChar *) map_sql_value_to_xml_value(value, exprType((Node *) e->expr)));
+ {
+ str = map_sql_value_to_xml_value(value,
+ exprType((Node *) e->expr));
+ arg_strings = lappend(arg_strings, str);
+ }
+ }
+
+ /* now safe to run libxml */
+ xml_init();
+
+ buf = xmlBufferCreate();
+ writer = xmlNewTextWriterMemory(buf, 0);
+
+ xmlTextWriterStartElement(writer, (xmlChar *) xexpr->name);
+
+ forboth(arg, named_arg_strings, narg, xexpr->arg_names)
+ {
+ char *str = (char *) lfirst(arg);
+ char *argname = strVal(lfirst(narg));
+
+ if (str)
+ {
+ xmlTextWriterWriteAttribute(writer,
+ (xmlChar *) argname,
+ (xmlChar *) str);
+ pfree(str);
+ }
+ }
+
+ foreach(arg, arg_strings)
+ {
+ char *str = (char *) lfirst(arg);
+
+ xmlTextWriterWriteRaw(writer, (xmlChar *) str);
}
xmlTextWriterEndElement(writer);
@@ -586,6 +625,7 @@ xmlelement(XmlExprState *xmlExpr, ExprContext *econtext)
result = xmlBuffer_to_xmltype(buf);
xmlBufferFree(buf);
+
return result;
#else
NO_XML_SUPPORT();
@@ -733,9 +773,10 @@ xmlvalidate(PG_FUNCTION_ARGS)
xml_init();
- /* We use a PG_TRY block to ensure libxml is cleaned up on error */
+ /* We use a PG_TRY block to ensure libxml parser is cleaned up on error */
PG_TRY();
{
+ xmlInitParser();
ctxt = xmlNewParserCtxt();
if (ctxt == NULL)
xml_ereport(ERROR, ERRCODE_INTERNAL_ERROR,
@@ -860,43 +901,64 @@ xml_is_document(xmltype *arg)
#ifdef USE_LIBXML
/*
- * Container for some init stuff (not good design!)
- * TODO xmlChar is utf8-char, make proper tuning (initdb with enc!=utf8 and check)
+ * Set up for use of libxml --- this should be called by each function that
+ * is about to use libxml facilities.
+ *
+ * TODO: xmlChar is utf8-char, make proper tuning (initdb with enc!=utf8 and
+ * check)
*/
static void
xml_init(void)
{
- /*
- * Currently, we have no pure UTF-8 support for internals -- check
- * if we can work.
- */
- if (sizeof (char) != sizeof (xmlChar))
- ereport(ERROR,
- (errmsg("could not initialize XML library"),
- errdetail("libxml2 has incompatible char type: sizeof(char)=%u, sizeof(xmlChar)=%u.",
- (int) sizeof(char), (int) sizeof(xmlChar))));
+ static bool first_time = true;
- if (xml_err_buf == NULL)
+ if (first_time)
{
- /* First time through: create error buffer in permanent context */
+ /* Stuff we need do only once per session */
MemoryContext oldcontext;
+ /*
+ * Currently, we have no pure UTF-8 support for internals -- check
+ * if we can work.
+ */
+ if (sizeof(char) != sizeof(xmlChar))
+ ereport(ERROR,
+ (errmsg("could not initialize XML library"),
+ errdetail("libxml2 has incompatible char type: sizeof(char)=%u, sizeof(xmlChar)=%u.",
+ (int) sizeof(char), (int) sizeof(xmlChar))));
+
+ /* create error buffer in permanent context */
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
xml_err_buf = makeStringInfo();
MemoryContextSwitchTo(oldcontext);
+
+ /* Now that xml_err_buf exists, safe to call xml_errorHandler */
+ xmlSetGenericErrorFunc(NULL, xml_errorHandler);
+
+ /* Set up memory allocation our way, too */
+ xmlMemSetup(xml_pfree, xml_palloc, xml_repalloc, xml_pstrdup);
+
+ /* Check library compatibility */
+ LIBXML_TEST_VERSION;
+
+ first_time = false;
}
else
{
/* Reset pre-existing buffer to empty */
+ Assert(xml_err_buf != NULL);
resetStringInfo(xml_err_buf);
- }
- /* Now that xml_err_buf exists, safe to call xml_errorHandler */
- xmlSetGenericErrorFunc(NULL, xml_errorHandler);
-
- xmlMemSetup(xml_pfree, xml_palloc, xml_repalloc, xml_pstrdup);
- xmlInitParser();
- LIBXML_TEST_VERSION;
+ /*
+ * We re-establish the callback functions every time. This makes it
+ * safe for other subsystems (PL/Perl, say) to also use libxml with
+ * their own callbacks ... so long as they likewise set up the
+ * callbacks on every use. It's cheap enough to not be worth
+ * worrying about, anyway.
+ */
+ xmlSetGenericErrorFunc(NULL, xml_errorHandler);
+ xmlMemSetup(xml_pfree, xml_palloc, xml_repalloc, xml_pstrdup);
+ }
}
@@ -1071,9 +1133,10 @@ print_xml_decl(StringInfo buf, const xmlChar *version, pg_enc encoding, int stan
appendStringInfo(buf, " version=\"%s\"", PG_XML_DEFAULT_VERSION);
if (encoding && encoding != PG_UTF8)
- /* XXX might be useful to convert this to IANA names
- * (ISO-8859-1 instead of LATIN1 etc.); needs field
- * experience */
+ /*
+ * XXX might be useful to convert this to IANA names
+ * (ISO-8859-1 instead of LATIN1 etc.); needs field experience
+ */
appendStringInfo(buf, " encoding=\"%s\"", pg_encoding_to_char(encoding));
if (standalone == 1)
@@ -1115,9 +1178,10 @@ xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, xml
xml_init();
- /* We use a PG_TRY block to ensure libxml is cleaned up on error */
+ /* We use a PG_TRY block to ensure libxml parser is cleaned up on error */
PG_TRY();
{
+ xmlInitParser();
ctxt = xmlNewParserCtxt();
if (ctxt == NULL)
xml_ereport(ERROR, ERRCODE_INTERNAL_ERROR,
@@ -1780,7 +1844,7 @@ schema_get_xml_visible_tables(Oid nspid)
StringInfoData query;
initStringInfo(&query);
- appendStringInfo(&query, "SELECT oid FROM pg_class WHERE relnamespace = %u AND relkind IN ('r', 'v') AND has_table_privilege (oid, 'SELECT') ORDER BY relname;", nspid);
+ appendStringInfo(&query, "SELECT oid FROM pg_catalog.pg_class WHERE relnamespace = %u AND relkind IN ('r', 'v') AND pg_catalog.has_table_privilege (oid, 'SELECT') ORDER BY relname;", nspid);
return query_to_oid_list(query.data);
}
@@ -1792,7 +1856,7 @@ schema_get_xml_visible_tables(Oid nspid)
*/
#define XML_VISIBLE_SCHEMAS_EXCLUDE "nspname LIKE 'pg_%' ESCAPE '' OR nspname = 'information_schema'"
-#define XML_VISIBLE_SCHEMAS "SELECT oid FROM pg_namespace WHERE has_schema_privilege (oid, 'USAGE') AND NOT (" XML_VISIBLE_SCHEMAS_EXCLUDE ")"
+#define XML_VISIBLE_SCHEMAS "SELECT oid FROM pg_catalog.pg_namespace WHERE pg_catalog.has_schema_privilege (oid, 'USAGE') AND NOT (" XML_VISIBLE_SCHEMAS_EXCLUDE ")"
static List *
@@ -1806,7 +1870,7 @@ static List *
database_get_xml_visible_tables(void)
{
/* At the moment there is no order required here. */
- return query_to_oid_list("SELECT oid FROM pg_class WHERE relkind IN ('r', 'v') AND has_table_privilege (pg_class.oid, 'SELECT') AND relnamespace IN (" XML_VISIBLE_SCHEMAS ");");
+ return query_to_oid_list("SELECT oid FROM pg_catalog.pg_class WHERE relkind IN ('r', 'v') AND pg_catalog.has_table_privilege (pg_class.oid, 'SELECT') AND relnamespace IN (" XML_VISIBLE_SCHEMAS ");");
}
@@ -2973,7 +3037,6 @@ SPI_sql_row_to_xmlelement(int rownum, StringInfo result, char *tablename, bool n
{
if (nulls)
appendStringInfo(result, " <%s xsi:nil='true'/>\n", colname);
-
}
else
appendStringInfo(result, " <%s>%s</%s>\n",
@@ -3170,10 +3233,12 @@ xpath(PG_FUNCTION_ARGS)
xml_init();
+ /* We use a PG_TRY block to ensure libxml parser is cleaned up on error */
PG_TRY();
{
+ xmlInitParser();
/*
- * redundant XML parsing (two parsings for the same value *
+ * redundant XML parsing (two parsings for the same value
* during one command execution are possible)
*/
ctxt = xmlNewParserCtxt();