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Diffstat (limited to 'contrib/xml2/xpath.c')
-rw-r--r--contrib/xml2/xpath.c162
1 files changed, 90 insertions, 72 deletions
diff --git a/contrib/xml2/xpath.c b/contrib/xml2/xpath.c
index 59f7c618645..522b88d2262 100644
--- a/contrib/xml2/xpath.c
+++ b/contrib/xml2/xpath.c
@@ -35,6 +35,15 @@ Datum xpath_table(PG_FUNCTION_ARGS);
void elog_error(const char *explain, bool force);
void pgxml_parser_init(void);
+/* workspace for pgxml_xpath() */
+
+typedef struct
+{
+ xmlDocPtr doctree;
+ xmlXPathContextPtr ctxt;
+ xmlXPathObjectPtr res;
+} xpath_workspace;
+
/* local declarations */
static void pgxml_errorHandler(void *ctxt, const char *msg,...);
@@ -48,7 +57,10 @@ static text *pgxml_result_to_text(xmlXPathObjectPtr res, xmlChar *toptag,
static xmlChar *pgxml_texttoxmlchar(text *textstring);
-static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar *xpath);
+static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar *xpath,
+ xpath_workspace *workspace);
+
+static void cleanup_workspace(xpath_workspace *workspace);
/* Global variables */
static char *pgxml_errorMsg = NULL; /* overall error message */
@@ -292,25 +304,22 @@ PG_FUNCTION_INFO_V1(xpath_nodeset);
Datum
xpath_nodeset(PG_FUNCTION_ARGS)
{
- xmlChar *xpath,
- *toptag,
- *septag;
- int32 pathsize;
- text *xpathsupp,
- *xpres;
-
- /* PG_GETARG_TEXT_P(0) is document buffer */
- xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
+ 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;
- toptag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
- septag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(3));
+ xpath = pgxml_texttoxmlchar(xpathsupp);
- pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+ res = pgxml_xpath(document, xpath, &workspace);
- xpath = pgxml_texttoxmlchar(xpathsupp);
+ xpres = pgxml_result_to_text(res, toptag, septag, NULL);
- xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
- toptag, septag, NULL);
+ cleanup_workspace(&workspace);
pfree(xpath);
@@ -328,23 +337,21 @@ PG_FUNCTION_INFO_V1(xpath_list);
Datum
xpath_list(PG_FUNCTION_ARGS)
{
- xmlChar *xpath,
- *plainsep;
- int32 pathsize;
- text *xpathsupp,
- *xpres;
-
- /* PG_GETARG_TEXT_P(0) is document buffer */
- xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
+ 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;
- plainsep = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
+ xpath = pgxml_texttoxmlchar(xpathsupp);
- pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+ res = pgxml_xpath(document, xpath, &workspace);
- xpath = pgxml_texttoxmlchar(xpathsupp);
+ xpres = pgxml_result_to_text(res, NULL, NULL, plainsep);
- xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
- NULL, NULL, plainsep);
+ cleanup_workspace(&workspace);
pfree(xpath);
@@ -359,13 +366,13 @@ PG_FUNCTION_INFO_V1(xpath_string);
Datum
xpath_string(PG_FUNCTION_ARGS)
{
+ text *document = PG_GETARG_TEXT_P(0);
+ text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
int32 pathsize;
- text *xpathsupp,
- *xpres;
-
- /* PG_GETARG_TEXT_P(0) is document buffer */
- xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
+ text *xpres;
+ xmlXPathObjectPtr res;
+ xpath_workspace workspace;
pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
@@ -376,13 +383,16 @@ xpath_string(PG_FUNCTION_ARGS)
/* We could try casting to string using the libxml function? */
xpath = (xmlChar *) palloc(pathsize + 9);
- memcpy((char *) (xpath + 7), VARDATA(xpathsupp), pathsize);
strncpy((char *) xpath, "string(", 7);
+ memcpy((char *) (xpath + 7), VARDATA(xpathsupp), pathsize);
xpath[pathsize + 7] = ')';
xpath[pathsize + 8] = '\0';
- xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
- NULL, NULL, NULL);
+ res = pgxml_xpath(document, xpath, &workspace);
+
+ xpres = pgxml_result_to_text(res, NULL, NULL, NULL);
+
+ cleanup_workspace(&workspace);
pfree(xpath);
@@ -397,21 +407,17 @@ PG_FUNCTION_INFO_V1(xpath_number);
Datum
xpath_number(PG_FUNCTION_ARGS)
{
+ text *document = PG_GETARG_TEXT_P(0);
+ text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
- int32 pathsize;
- text *xpathsupp;
float4 fRes;
-
xmlXPathObjectPtr res;
-
- /* PG_GETARG_TEXT_P(0) is document buffer */
- xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
-
- pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+ xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
- res = pgxml_xpath(PG_GETARG_TEXT_P(0), xpath);
+ res = pgxml_xpath(document, xpath, &workspace);
+
pfree(xpath);
if (res == NULL)
@@ -419,6 +425,8 @@ xpath_number(PG_FUNCTION_ARGS)
fRes = xmlXPathCastToNumber(res);
+ cleanup_workspace(&workspace);
+
if (xmlXPathIsNaN(fRes))
PG_RETURN_NULL();
@@ -431,21 +439,17 @@ PG_FUNCTION_INFO_V1(xpath_bool);
Datum
xpath_bool(PG_FUNCTION_ARGS)
{
+ text *document = PG_GETARG_TEXT_P(0);
+ text *xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
xmlChar *xpath;
- int32 pathsize;
- text *xpathsupp;
int bRes;
-
xmlXPathObjectPtr res;
-
- /* PG_GETARG_TEXT_P(0) is document buffer */
- xpathsupp = PG_GETARG_TEXT_P(1); /* XPath expression */
-
- pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+ xpath_workspace workspace;
xpath = pgxml_texttoxmlchar(xpathsupp);
- res = pgxml_xpath(PG_GETARG_TEXT_P(0), xpath);
+ res = pgxml_xpath(document, xpath, &workspace);
+
pfree(xpath);
if (res == NULL)
@@ -453,6 +457,8 @@ xpath_bool(PG_FUNCTION_ARGS)
bRes = xmlXPathCastToBoolean(res);
+ cleanup_workspace(&workspace);
+
PG_RETURN_BOOL(bRes);
}
@@ -461,48 +467,60 @@ xpath_bool(PG_FUNCTION_ARGS)
/* Core function to evaluate XPath query */
static xmlXPathObjectPtr
-pgxml_xpath(text *document, xmlChar *xpath)
+pgxml_xpath(text *document, xmlChar *xpath, xpath_workspace *workspace)
{
- xmlDocPtr doctree;
- xmlXPathContextPtr ctxt;
+ int32 docsize = VARSIZE(document) - VARHDRSZ;
xmlXPathObjectPtr res;
xmlXPathCompExprPtr comppath;
- int32 docsize;
- docsize = VARSIZE(document) - VARHDRSZ;
+ workspace->doctree = NULL;
+ workspace->ctxt = NULL;
+ workspace->res = NULL;
pgxml_parser_init();
- doctree = xmlParseMemory((char *) VARDATA(document), docsize);
- if (doctree == NULL)
+ workspace->doctree = xmlParseMemory((char *) VARDATA(document), docsize);
+ if (workspace->doctree == NULL)
return NULL; /* not well-formed */
- ctxt = xmlXPathNewContext(doctree);
- ctxt->node = xmlDocGetRootElement(doctree);
+ workspace->ctxt = xmlXPathNewContext(workspace->doctree);
+ workspace->ctxt->node = xmlDocGetRootElement(workspace->doctree);
/* compile the path */
comppath = xmlXPathCompile(xpath);
if (comppath == NULL)
{
- xmlFreeDoc(doctree);
+ cleanup_workspace(workspace);
elog_error("XPath Syntax Error", true);
}
/* Now evaluate the path expression. */
- res = xmlXPathCompiledEval(comppath, ctxt);
+ res = xmlXPathCompiledEval(comppath, workspace->ctxt);
+ workspace->res = res;
+
xmlXPathFreeCompExpr(comppath);
if (res == NULL)
- {
- xmlXPathFreeContext(ctxt);
- xmlFreeDoc(doctree);
+ cleanup_workspace(workspace);
- return NULL;
- }
- /* xmlFreeDoc(doctree); */
return res;
}
+/* Clean up after processing the result of pgxml_xpath() */
+static void
+cleanup_workspace(xpath_workspace *workspace)
+{
+ if (workspace->res)
+ xmlXPathFreeObject(workspace->res);
+ workspace->res = NULL;
+ if (workspace->ctxt)
+ xmlXPathFreeContext(workspace->ctxt);
+ workspace->ctxt = NULL;
+ if (workspace->doctree)
+ xmlFreeDoc(workspace->doctree);
+ workspace->doctree = NULL;
+}
+
static text *
pgxml_result_to_text(xmlXPathObjectPtr res,
xmlChar *toptag,
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-20 03:40:15 +0000