Back-patch today's memory management fixups in contrib/xml2.

Prior to 8.3, these changes are not critical for compatibility with core
Postgres, since core had no libxml2 calls then.  However there is still
a risk if contrib/xml2 is used along with libxml2 functionality in Perl
or other loadable modules.  So back-patch to all versions.

Also back-patch addition of regression tests.  I'm not sure how many of
the cases are interesting without the interaction with core xml code,
but a silly regression test is still better than none at all.
This commit is contained in:
Tom Lane 2010-03-01 03:41:17 +00:00
parent a68bdfbcaa
commit 2502898d73
5 changed files with 400 additions and 237 deletions

View File

@ -10,6 +10,7 @@ SHLIB_LINK = -lxslt -lxml2
DATA_built = pgxml.sql
DATA = uninstall_pgxml.sql
REGRESS = xml2
DOCS = README.xml2
PG_CPPFLAGS := $(shell xml2-config --cflags)

View File

@ -0,0 +1,142 @@
--
-- first, define the functions. Turn off echoing so that expected file
-- does not depend on contents of pgxml.sql.
--
SET client_min_messages = warning;
\set ECHO none
RESET client_min_messages;
select xslt_process(
'<table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<row>
<x>1</x>
</row>
<row>
<x>2</x>
</row>
<row>
<x>3</x>
</row>
<row>
<x>4</x>
</row>
<row>
<x>5</x>
</row>
</table>'::text,
$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes" />
<xsl:template match="*">
<xsl:copy>
<xsl:copy-of select="@*" />
<xsl:apply-templates />
</xsl:copy>
</xsl:template>
<xsl:template match="comment()|processing-instruction()">
<xsl:copy />
</xsl:template>
</xsl:stylesheet>
$$::text);
xslt_process
---------------------------------------------------------------
<?xml version="1.0"?>
<table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<row>
<x>1</x>
</row>
<row>
<x>2</x>
</row>
<row>
<x>3</x>
</row>
<row>
<x>4</x>
</row>
<row>
<x>5</x>
</row>
</table>
(1 row)
CREATE TABLE xpath_test (id integer NOT NULL, t text);
INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
as t(id int4);
id
----
(0 rows)
SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
as t(id int4, doc int4);
id | doc
----+-----
1 | 1
(1 row)
create table articles (article_id integer, article_xml text, date_entered date);
insert into articles (article_id, article_xml, date_entered)
values (2, '<article><author>test</author><pages>37</pages></article>', now());
SELECT * FROM
xpath_table('article_id',
'article_xml',
'articles',
'/article/author|/article/pages|/article/title',
'date_entered > ''2003-01-01'' ')
AS t(article_id integer, author text, page_count integer, title text);
article_id | author | page_count | title
------------+--------+------------+-------
2 | test | 37 |
(1 row)
-- this used to fail when invoked a second time
select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>$$);
xslt_process
-----------------------
<?xml version="1.0"?>
<aaa/>
(1 row)
select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>$$);
xslt_process
-----------------------
<?xml version="1.0"?>
<aaa/>
(1 row)
create table t1 (id integer, xml_data text);
insert into t1 (id, xml_data)
values
(1, '<attributes><attribute name="attr_1">Some
Value</attribute></attributes>');
create index idx_xpath on t1 ( xpath_string
('/attributes/attribute[@name="attr_1"]/text()', xml_data));

94
contrib/xml2/sql/xml2.sql Normal file
View File

@ -0,0 +1,94 @@
--
-- first, define the functions. Turn off echoing so that expected file
-- does not depend on contents of pgxml.sql.
--
SET client_min_messages = warning;
\set ECHO none
\i pgxml.sql
\set ECHO all
RESET client_min_messages;
select xslt_process(
'<table xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<row>
<x>1</x>
</row>
<row>
<x>2</x>
</row>
<row>
<x>3</x>
</row>
<row>
<x>4</x>
</row>
<row>
<x>5</x>
</row>
</table>'::text,
$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes" />
<xsl:template match="*">
<xsl:copy>
<xsl:copy-of select="@*" />
<xsl:apply-templates />
</xsl:copy>
</xsl:template>
<xsl:template match="comment()|processing-instruction()">
<xsl:copy />
</xsl:template>
</xsl:stylesheet>
$$::text);
CREATE TABLE xpath_test (id integer NOT NULL, t text);
INSERT INTO xpath_test VALUES (1, '<doc><int>1</int></doc>');
SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
as t(id int4);
SELECT * FROM xpath_table('id', 't', 'xpath_test', '/doc/int', 'true')
as t(id int4, doc int4);
create table articles (article_id integer, article_xml text, date_entered date);
insert into articles (article_id, article_xml, date_entered)
values (2, '<article><author>test</author><pages>37</pages></article>', now());
SELECT * FROM
xpath_table('article_id',
'article_xml',
'articles',
'/article/author|/article/pages|/article/title',
'date_entered > ''2003-01-01'' ')
AS t(article_id integer, author text, page_count integer, title text);
-- this used to fail when invoked a second time
select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>$$);
select xslt_process('<aaa/>',$$<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="@*|node()">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>$$);
create table t1 (id integer, xml_data text);
insert into t1 (id, xml_data)
values
(1, '<attributes><attribute name="attr_1">Some
Value</attribute></attributes>');
create index idx_xpath on t1 ( xpath_string
('/attributes/attribute[@name="attr_1"]/text()', xml_data));

View File

@ -19,28 +19,7 @@
PG_MODULE_MAGIC;
/* declarations */
static void *pgxml_palloc(size_t size);
static void *pgxml_repalloc(void *ptr, size_t size);
static void pgxml_pfree(void *ptr);
static char *pgxml_pstrdup(const char *string);
static void pgxml_errorHandler(void *ctxt, const char *msg,...);
void elog_error(int level, char *explain, int force);
void pgxml_parser_init(void);
static xmlChar *pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
xmlChar * toptagname, xmlChar * septagname,
xmlChar * plainsep);
text *pgxml_result_to_text(xmlXPathObjectPtr res, xmlChar * toptag,
xmlChar * septag, xmlChar * plainsep);
xmlChar *pgxml_texttoxmlchar(text *textstring);
static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar * xpath);
/* externally accessible functions */
Datum xml_is_well_formed(PG_FUNCTION_ARGS);
Datum xml_encode_special_chars(PG_FUNCTION_ARGS);
@ -51,116 +30,100 @@ Datum xpath_bool(PG_FUNCTION_ARGS);
Datum xpath_list(PG_FUNCTION_ARGS);
Datum xpath_table(PG_FUNCTION_ARGS);
/* these are exported for use by xslt_proc.c */
void elog_error(const char *explain, bool force);
void pgxml_parser_init(void);
/* local declarations */
static void pgxml_errorHandler(void *ctxt, const char *msg,...);
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);
/* Global variables */
char *errbuf; /* per line error buffer */
char *pgxml_errorMsg = NULL; /* overall error message */
static char *pgxml_errorMsg = NULL; /* overall error message */
/* Convenience macros */
#define GET_TEXT(cstrp) DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(cstrp)))
#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
#define ERRBUF_SIZE 200
/* memory handling passthrough functions (e.g. palloc, pstrdup are
currently macros, and the others might become so...) */
static void *
pgxml_palloc(size_t size)
{
/* elog(DEBUG1,"Alloc %d in CMC %p",size,CurrentMemoryContext); */
return palloc(size);
}
static void *
pgxml_repalloc(void *ptr, size_t size)
{
/* elog(DEBUG1,"ReAlloc in CMC %p",CurrentMemoryContext);*/
return repalloc(ptr, size);
}
static void
pgxml_pfree(void *ptr)
{
/* elog(DEBUG1,"Free in CMC %p",CurrentMemoryContext); */
pfree(ptr);
}
static char *
pgxml_pstrdup(const char *string)
{
return pstrdup(string);
}
/* The error handling function. This formats an error message and sets
/*
* The error handling function. This formats an error message and sets
* a flag - an ereport will be issued prior to return
*/
static void
pgxml_errorHandler(void *ctxt, const char *msg,...)
{
char errbuf[1024]; /* per line error buffer */
va_list args;
/* Format the message */
va_start(args, msg);
vsnprintf(errbuf, ERRBUF_SIZE, msg, args);
vsnprintf(errbuf, sizeof(errbuf), msg, args);
va_end(args);
/* Now copy the argument across */
/* Store in, or append to, pgxml_errorMsg */
if (pgxml_errorMsg == NULL)
pgxml_errorMsg = pstrdup(errbuf);
else
{
int32 xsize = strlen(pgxml_errorMsg);
pgxml_errorMsg = repalloc(pgxml_errorMsg,
(size_t) (xsize + strlen(errbuf) + 1));
strncpy(&pgxml_errorMsg[xsize - 1], errbuf, strlen(errbuf));
pgxml_errorMsg[xsize + strlen(errbuf) - 1] = '\0';
size_t oldsize = strlen(pgxml_errorMsg);
size_t newsize = strlen(errbuf);
/*
* We intentionally discard the last char of the existing message,
* which should be a carriage return. (XXX wouldn't it be saner
* to keep it?)
*/
pgxml_errorMsg = repalloc(pgxml_errorMsg, oldsize + newsize);
memcpy(&pgxml_errorMsg[oldsize - 1], errbuf, newsize);
pgxml_errorMsg[oldsize + newsize - 1] = '\0';
}
memset(errbuf, 0, ERRBUF_SIZE);
}
/* This function reports the current message at the level specified */
/*
* This function ereports the current message if any. If force is true
* then an error is thrown even if pgxml_errorMsg hasn't been set.
*/
void
elog_error(int level, char *explain, int force)
elog_error(const char *explain, bool force)
{
if (force || (pgxml_errorMsg != NULL))
if (force || pgxml_errorMsg != NULL)
{
if (pgxml_errorMsg == NULL)
{
ereport(level, (errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg(explain)));
}
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("%s", explain)));
else
{
ereport(level, (errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("%s:%s", explain, pgxml_errorMsg)));
pfree(pgxml_errorMsg);
}
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_EXCEPTION),
errmsg("%s: %s", explain, pgxml_errorMsg)));
}
}
/*
* Initialize for xml parsing.
*/
void
pgxml_parser_init()
pgxml_parser_init(void)
{
/*
* This code could also set parser settings from user-supplied info.
* Quite how these settings are made is another matter :)
*/
xmlMemSetup(pgxml_pfree, pgxml_palloc, pgxml_repalloc, pgxml_pstrdup);
xmlInitParser();
/* Set up error handling */
pgxml_errorMsg = NULL;
xmlSetGenericErrorFunc(NULL, pgxml_errorHandler);
/* Initialize libxml */
xmlInitParser();
xmlSubstituteEntitiesDefault(1);
xmlLoadExtDtdDefaultValue = 1;
pgxml_errorMsg = NULL;
errbuf = palloc(200);
memset(errbuf, 0, 200);
}
@ -171,10 +134,9 @@ PG_FUNCTION_INFO_V1(xml_is_well_formed);
Datum
xml_is_well_formed(PG_FUNCTION_ARGS)
{
/* called as xml_is_well_formed(document) */
xmlDocPtr doctree;
text *t = PG_GETARG_TEXT_P(0); /* document buffer */
int32 docsize = VARSIZE(t) - VARHDRSZ;
xmlDocPtr doctree;
pgxml_parser_init();
@ -184,8 +146,8 @@ xml_is_well_formed(PG_FUNCTION_ARGS)
xmlCleanupParser();
PG_RETURN_BOOL(false); /* i.e. not well-formed */
}
xmlCleanupParser();
xmlFreeDoc(doctree);
xmlCleanupParser();
PG_RETURN_BOOL(true);
}
@ -219,28 +181,23 @@ xml_encode_special_chars(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(tout);
}
static xmlChar
*
/*
* Function translates a nodeset into a text representation
*
* iterates over each node in the set and calls xmlNodeDump to write it to
* an xmlBuffer -from which an xmlChar * string is returned.
*
* each representation is surrounded by <tagname> ... </tagname>
*
* plainsep is an ordinary (not tag) separator - if used, then nodes are
* cast to string as output method
*/
static xmlChar *
pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
xmlChar * toptagname,
xmlChar * septagname,
xmlChar * plainsep)
xmlChar *toptagname,
xmlChar *septagname,
xmlChar *plainsep)
{
/* Function translates a nodeset into a text representation */
/*
* iterates over each node in the set and calls xmlNodeDump to write it to
* an xmlBuffer -from which an xmlChar * string is returned.
*/
/* each representation is surrounded by <tagname> ... </tagname> */
/*
* plainsep is an ordinary (not tag) seperator - if used, then nodes are
* cast to string as output method
*/
xmlBufferPtr buf;
xmlChar *result;
int i;
@ -257,7 +214,6 @@ pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
{
for (i = 0; i < nodeset->nodeNr; i++)
{
if (plainsep != NULL)
{
xmlBufferWriteCHAR(buf,
@ -269,8 +225,6 @@ pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
}
else
{
if ((septagname != NULL) && (xmlStrlen(septagname) > 0))
{
xmlBufferWriteChar(buf, "<");
@ -307,8 +261,7 @@ pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
/* Translate a PostgreSQL "varlena" -i.e. a variable length parameter
* into the libxml2 representation
*/
xmlChar *
static xmlChar *
pgxml_texttoxmlchar(text *textstring)
{
xmlChar *res;
@ -321,12 +274,12 @@ pgxml_texttoxmlchar(text *textstring)
return res;
}
/* Public visible XPath functions */
/* Publicly visible XPath functions */
/* This is a "raw" xpath function. Check that it returns child elements
/*
* This is a "raw" xpath function. Check that it returns child elements
* properly
*/
PG_FUNCTION_INFO_V1(xpath_nodeset);
Datum
@ -336,8 +289,7 @@ xpath_nodeset(PG_FUNCTION_ARGS)
*toptag,
*septag;
int32 pathsize;
text
*xpathsupp,
text *xpathsupp,
*xpres;
/* PG_GETARG_TEXT_P(0) is document buffer */
@ -350,8 +302,7 @@ xpath_nodeset(PG_FUNCTION_ARGS)
xpath = pgxml_texttoxmlchar(xpathsupp);
xpres = pgxml_result_to_text(
pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
toptag, septag, NULL);
/* xmlCleanupParser(); done by result_to_text routine */
@ -362,9 +313,10 @@ xpath_nodeset(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(xpres);
}
/* The following function is almost identical, but returns the elements in */
/* a list. */
/*
* The following function is almost identical, but returns the elements in
* a list.
*/
PG_FUNCTION_INFO_V1(xpath_list);
Datum
@ -373,8 +325,7 @@ xpath_list(PG_FUNCTION_ARGS)
xmlChar *xpath,
*plainsep;
int32 pathsize;
text
*xpathsupp,
text *xpathsupp,
*xpres;
/* PG_GETARG_TEXT_P(0) is document buffer */
@ -386,8 +337,7 @@ xpath_list(PG_FUNCTION_ARGS)
xpath = pgxml_texttoxmlchar(xpathsupp);
xpres = pgxml_result_to_text(
pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
NULL, NULL, plainsep);
/* xmlCleanupParser(); done by result_to_text routine */
@ -406,8 +356,7 @@ xpath_string(PG_FUNCTION_ARGS)
{
xmlChar *xpath;
int32 pathsize;
text
*xpathsupp,
text *xpathsupp,
*xpres;
/* PG_GETARG_TEXT_P(0) is document buffer */
@ -427,8 +376,7 @@ xpath_string(PG_FUNCTION_ARGS)
xpath[pathsize + 7] = ')';
xpath[pathsize + 8] = '\0';
xpres = pgxml_result_to_text(
pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
NULL, NULL, NULL);
xmlCleanupParser();
@ -447,9 +395,7 @@ xpath_number(PG_FUNCTION_ARGS)
{
xmlChar *xpath;
int32 pathsize;
text
*xpathsupp;
text *xpathsupp;
float4 fRes;
xmlXPathObjectPtr res;
@ -476,7 +422,6 @@ xpath_number(PG_FUNCTION_ARGS)
PG_RETURN_NULL();
PG_RETURN_FLOAT4(fRes);
}
@ -487,9 +432,7 @@ xpath_bool(PG_FUNCTION_ARGS)
{
xmlChar *xpath;
int32 pathsize;
text
*xpathsupp;
text *xpathsupp;
int bRes;
xmlXPathObjectPtr res;
@ -513,26 +456,21 @@ xpath_bool(PG_FUNCTION_ARGS)
bRes = xmlXPathCastToBoolean(res);
xmlCleanupParser();
PG_RETURN_BOOL(bRes);
}
/* Core function to evaluate XPath query */
xmlXPathObjectPtr
pgxml_xpath(text *document, xmlChar * xpath)
static xmlXPathObjectPtr
pgxml_xpath(text *document, xmlChar *xpath)
{
xmlDocPtr doctree;
xmlXPathContextPtr ctxt;
xmlXPathObjectPtr res;
xmlXPathCompExprPtr comppath;
int32 docsize;
docsize = VARSIZE(document) - VARHDRSZ;
pgxml_parser_init();
@ -546,16 +484,13 @@ pgxml_xpath(text *document, xmlChar * xpath)
ctxt = xmlXPathNewContext(doctree);
ctxt->node = xmlDocGetRootElement(doctree);
/* compile the path */
comppath = xmlXPathCompile(xpath);
if (comppath == NULL)
{
xmlCleanupParser();
xmlFreeDoc(doctree);
elog_error(ERROR, "XPath Syntax Error", 1);
return NULL;
elog_error("XPath Syntax Error", true);
}
/* Now evaluate the path expression. */
@ -574,12 +509,11 @@ pgxml_xpath(text *document, xmlChar * xpath)
return res;
}
text
*
static text *
pgxml_result_to_text(xmlXPathObjectPtr res,
xmlChar * toptag,
xmlChar * septag,
xmlChar * plainsep)
xmlChar *toptag,
xmlChar *septag,
xmlChar *plainsep)
{
xmlChar *xpresstr;
int32 ressize;
@ -607,7 +541,6 @@ pgxml_result_to_text(xmlXPathObjectPtr res,
xpresstr = xmlStrdup("<unsupported/>");
}
/* Now convert this result back to text */
ressize = strlen(xpresstr);
xpres = (text *) palloc(ressize + VARHDRSZ);
@ -620,27 +553,33 @@ pgxml_result_to_text(xmlXPathObjectPtr res,
xmlFree(xpresstr);
elog_error(ERROR, "XPath error", 0);
elog_error("XPath error", false);
return xpres;
}
/* xpath_table is a table function. It needs some tidying (as do the
/*
* xpath_table is a table function. It needs some tidying (as do the
* other functions here!
*/
PG_FUNCTION_INFO_V1(xpath_table);
Datum
xpath_table(PG_FUNCTION_ARGS)
{
/* SPI (input tuple) support */
/* Function parameters */
char *pkeyfield = GET_STR(PG_GETARG_TEXT_P(0));
char *xmlfield = GET_STR(PG_GETARG_TEXT_P(1));
char *relname = GET_STR(PG_GETARG_TEXT_P(2));
char *xpathset = GET_STR(PG_GETARG_TEXT_P(3));
char *condition = GET_STR(PG_GETARG_TEXT_P(4));
/* SPI (input tuple) support */
SPITupleTable *tuptable;
HeapTuple spi_tuple;
TupleDesc spi_tupdesc;
/* Output tuple (tuplestore) support */
/* Output tuple (tuplestore) support */
Tuplestorestate *tupstore = NULL;
TupleDesc ret_tupdesc;
HeapTuple ret_tuple;
@ -650,13 +589,6 @@ xpath_table(PG_FUNCTION_ARGS)
MemoryContext per_query_ctx;
MemoryContext oldcontext;
/* Function parameters */
char *pkeyfield = GET_STR(PG_GETARG_TEXT_P(0));
char *xmlfield = GET_STR(PG_GETARG_TEXT_P(1));
char *relname = GET_STR(PG_GETARG_TEXT_P(2));
char *xpathset = GET_STR(PG_GETARG_TEXT_P(3));
char *condition = GET_STR(PG_GETARG_TEXT_P(4));
char **values;
xmlChar **xpaths;
xmlChar *pos;
@ -669,8 +601,7 @@ xpath_table(PG_FUNCTION_ARGS)
int j;
int rownr; /* For issuing multiple rows from one original
* document */
int had_values; /* To determine end of nodeset results */
bool had_values; /* To determine end of nodeset results */
StringInfoData query_buf;
/* We only have a valid tuple description in table function mode */
@ -697,7 +628,6 @@ xpath_table(PG_FUNCTION_ARGS)
* 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);
@ -712,6 +642,12 @@ xpath_table(PG_FUNCTION_ARGS)
/* 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
@ -727,26 +663,27 @@ xpath_table(PG_FUNCTION_ARGS)
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 */
/*
* Split XPaths. xpathset is a writable CString.
*
* Note that we stop splitting once we've done all needed for tupdesc
*/
numpaths = 0;
pos = xpathset;
do
while (numpaths < (ret_tupdesc->natts - 1))
{
xpaths[numpaths] = pos;
xpaths[numpaths++] = (xmlChar *) pos;
pos = strstr(pos, pathsep);
if (pos != NULL)
{
*pos = '\0';
pos++;
}
numpaths++;
} while ((pos != NULL) && (numpaths < (ret_tupdesc->natts - 1)));
else
break;
}
/* Now build query */
initStringInfo(&query_buf);
@ -756,30 +693,28 @@ xpath_table(PG_FUNCTION_ARGS)
pkeyfield,
xmlfield,
relname,
condition
);
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);
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 */
/* 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.
*/
/*
* 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),
@ -787,10 +722,12 @@ xpath_table(PG_FUNCTION_ARGS)
errdetail("Expected two columns in SPI result, got %d.", spi_tupdesc->natts)));
}
/* Setup the parser. Beware that this must happen in the same context as the
* cleanup - which means that any error from here on must do cleanup to
* ensure that the entity table doesn't get freed by being out of context.
*/
/*
* Setup the parser. Beware that this must happen in the same context as
* the cleanup - which means that any error from here on must do cleanup
* to ensure that the entity table doesn't get freed by being out of
* context.
*/
pgxml_parser_init();
/* For each row i.e. document returned from SPI */
@ -798,13 +735,10 @@ xpath_table(PG_FUNCTION_ARGS)
{
char *pkey;
char *xmldoc;
xmlDocPtr doctree;
xmlXPathContextPtr ctxt;
xmlXPathObjectPtr res;
xmlChar *resstr;
xmlXPathCompExprPtr comppath;
/* Extract the row data as C Strings */
@ -814,10 +748,9 @@ xpath_table(PG_FUNCTION_ARGS)
/*
* Clear the values array, so that not-well-formed documents return
* NULL in all columns.
* NULL in all columns. Note that this also means that spare columns
* will be NULL.
*/
/* Note that this also means that spare columns will be NULL. */
for (j = 0; j < ret_tupdesc->natts; j++)
values[j] = NULL;
@ -845,10 +778,9 @@ xpath_table(PG_FUNCTION_ARGS)
do
{
/* Now evaluate the set of xpaths. */
had_values = 0;
had_values = false;
for (j = 0; j < numpaths; j++)
{
ctxt = xmlXPathNewContext(doctree);
ctxt->node = xmlDocGetRootElement(doctree);
xmlSetGenericErrorFunc(ctxt, pgxml_errorHandler);
@ -859,10 +791,7 @@ xpath_table(PG_FUNCTION_ARGS)
{
xmlCleanupParser();
xmlFreeDoc(doctree);
elog_error(ERROR, "XPath Syntax Error", 1);
PG_RETURN_NULL(); /* Keep compiler happy */
elog_error("XPath Syntax Error", true);
}
/* Now evaluate the path expression. */
@ -875,11 +804,12 @@ xpath_table(PG_FUNCTION_ARGS)
{
case XPATH_NODESET:
/* We see if this nodeset has enough nodes */
if ((res->nodesetval != NULL) && (rownr < res->nodesetval->nodeNr))
if (res->nodesetval != NULL &&
rownr < res->nodesetval->nodeNr)
{
resstr =
xmlXPathCastNodeToString(res->nodesetval->nodeTab[rownr]);
had_values = 1;
had_values = true;
}
else
resstr = NULL;
@ -895,7 +825,6 @@ xpath_table(PG_FUNCTION_ARGS)
resstr = xmlStrdup("<unsupported/>");
}
/*
* Insert this into the appropriate column in the
* result tuple.
@ -904,6 +833,7 @@ xpath_table(PG_FUNCTION_ARGS)
}
xmlXPathFreeContext(ctxt);
}
/* Now add the tuple to the output, if there is one. */
if (had_values)
{
@ -913,9 +843,7 @@ xpath_table(PG_FUNCTION_ARGS)
}
rownr++;
} while (had_values);
}
xmlFreeDoc(doctree);
@ -927,7 +855,7 @@ xpath_table(PG_FUNCTION_ARGS)
}
xmlCleanupParser();
/* Needed to flag completeness in 7.3.1. 7.4 defines it as a no-op. */
tuplestore_donestoring(tupstore);
SPI_finish();
@ -942,5 +870,4 @@ xpath_table(PG_FUNCTION_ARGS)
* expecting.
*/
return (Datum) 0;
}

View File

@ -21,22 +21,21 @@
#include <libxslt/xsltutils.h>
/* externally accessible functions */
Datum xslt_process(PG_FUNCTION_ARGS);
/* declarations to come from xpath.c */
extern void elog_error(int level, char *explain, int force);
extern void pgxml_parser_init();
extern xmlChar *pgxml_texttoxmlchar(text *textstring);
#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
extern void elog_error(const char *explain, bool force);
extern void pgxml_parser_init(void);
/* local defs */
static void parse_params(const char **params, text *paramstr);
Datum xslt_process(PG_FUNCTION_ARGS);
#define MAXPARAMS 20 /* must be even, see parse_params() */
#define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
PG_FUNCTION_INFO_V1(xslt_process);
@ -82,7 +81,7 @@ xslt_process(PG_FUNCTION_ARGS)
if (doctree == NULL)
{
xmlCleanupParser();
elog_error(ERROR, "error parsing XML document", 0);
elog_error("error parsing XML document", false);
PG_RETURN_NULL();
}
@ -96,7 +95,7 @@ xslt_process(PG_FUNCTION_ARGS)
{
xmlFreeDoc(doctree);
xmlCleanupParser();
elog_error(ERROR, "error parsing stylesheet as XML document", 0);
elog_error("error parsing stylesheet as XML document", false);
PG_RETURN_NULL();
}
@ -111,7 +110,7 @@ xslt_process(PG_FUNCTION_ARGS)
xmlFreeDoc(doctree);
xsltCleanupGlobals();
xmlCleanupParser();
elog_error(ERROR, "failed to parse stylesheet", 0);
elog_error("failed to parse stylesheet", false);
PG_RETURN_NULL();
}