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SAX2: Fix quadratic behavior in xmlSAX2AttributeNs

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The last missing piece to make parsing of attributes O(n).
This commit is contained in:
Nick Wellnhofer 2023-11-04 20:21:54 +01:00
parent a40c32ac1f
commit a31e1b0665
1 changed files with 52 additions and 43 deletions
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95
SAX2.c
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@ -1855,8 +1855,10 @@ decode:
* The default handling is to convert the attribute into an
* DOM subtree and past it in a new xmlAttr element added to
* the element.
*
* Returns the new attribute or NULL in case of error.
*/
static void
static xmlAttrPtr
xmlSAX2AttributeNs(xmlParserCtxtPtr ctxt,
const xmlChar * localname,
const xmlChar * prefix,
@ -1884,43 +1886,29 @@ xmlSAX2AttributeNs(xmlParserCtxtPtr ctxt,
ret = ctxt->freeAttrs;
ctxt->freeAttrs = ret->next;
ctxt->freeAttrsNr--;
memset(ret, 0, sizeof(xmlAttr));
ret->type = XML_ATTRIBUTE_NODE;
ret->parent = ctxt->node;
ret->doc = ctxt->myDoc;
ret->ns = namespace;
if (ctxt->dictNames)
ret->name = localname;
else
ret->name = xmlStrdup(localname);
/* link at the end to preserve order, TODO speed up with a last */
if (ctxt->node->properties == NULL) {
ctxt->node->properties = ret;
} else {
xmlAttrPtr prev = ctxt->node->properties;
while (prev->next != NULL) prev = prev->next;
prev->next = ret;
ret->prev = prev;
}
if ((__xmlRegisterCallbacks) && (xmlRegisterNodeDefaultValue))
xmlRegisterNodeDefaultValue((xmlNodePtr)ret);
} else {
if (ctxt->dictNames)
ret = xmlNewNsPropEatName(ctxt->node, namespace,
(xmlChar *) localname, NULL);
else
ret = xmlNewNsProp(ctxt->node, namespace, localname, NULL);
if (ret == NULL) {
xmlErrMemory(ctxt, "xmlSAX2AttributeNs");
return;
}
ret = xmlMalloc(sizeof(*ret));
if (ret == NULL) {
xmlSAX2ErrMemory(ctxt, NULL);
return(NULL);
}
}
memset(ret, 0, sizeof(xmlAttr));
ret->type = XML_ATTRIBUTE_NODE;
ret->parent = ctxt->node;
ret->doc = ctxt->myDoc;
ret->ns = namespace;
if (ctxt->dictNames)
ret->name = localname;
else
ret->name = xmlStrdup(localname);
if ((__xmlRegisterCallbacks) && (xmlRegisterNodeDefaultValue))
xmlRegisterNodeDefaultValue((xmlNodePtr)ret);
if ((ctxt->replaceEntities == 0) && (!ctxt->html)) {
xmlNodePtr tmp;
@ -2065,6 +2053,8 @@ xmlSAX2AttributeNs(xmlParserCtxtPtr ctxt,
}
if (dup != NULL)
xmlFree(dup);
return(ret);
}
/**
@ -2275,7 +2265,11 @@ xmlSAX2StartElementNs(void *ctx,
* process all the other attributes
*/
if (nb_attributes > 0) {
xmlAttrPtr prev = NULL;
for (j = 0,i = 0;i < nb_attributes;i++,j+=5) {
xmlAttrPtr attr = NULL;
/*
* Handle the rare case of an undefined attribute prefix
*/
@ -2286,23 +2280,38 @@ xmlSAX2StartElementNs(void *ctx,
fullname = xmlDictQLookup(ctxt->dict, attributes[j+1],
attributes[j]);
if (fullname != NULL) {
xmlSAX2AttributeNs(ctxt, fullname, NULL,
attributes[j+3], attributes[j+4]);
continue;
attr = xmlSAX2AttributeNs(ctxt, fullname, NULL,
attributes[j+3],
attributes[j+4]);
goto have_attr;
}
} else {
lname = xmlBuildQName(attributes[j], attributes[j+1],
NULL, 0);
if (lname != NULL) {
xmlSAX2AttributeNs(ctxt, lname, NULL,
attributes[j+3], attributes[j+4]);
attr = xmlSAX2AttributeNs(ctxt, lname, NULL,
attributes[j+3],
attributes[j+4]);
xmlFree(lname);
continue;
goto have_attr;
}
}
}
xmlSAX2AttributeNs(ctxt, attributes[j], attributes[j+1],
attributes[j+3], attributes[j+4]);
attr = xmlSAX2AttributeNs(ctxt, attributes[j], attributes[j+1],
attributes[j+3], attributes[j+4]);
have_attr:
if (attr == NULL)
continue;
/* link at the end to preserve order */
if (prev == NULL) {
ctxt->node->properties = attr;
} else {
prev->next = attr;
attr->prev = prev;
}
prev = attr;
}
}