#include <xml_node_set.h>
#include <libxml/xpathInternals.h>
/*
* call-seq:
* dup
*
* Duplicate this node set
*/
static VALUE duplicate(VALUE self)
{
xmlNodeSetPtr node_set;
Data_Get_Struct(self, xmlNodeSet, node_set);
xmlNodeSetPtr dupl = xmlXPathNodeSetMerge(NULL, node_set);
return Nokogiri_wrap_xml_node_set(dupl);
}
/*
* call-seq:
* length
*
* Get the length of the node set
*/
static VALUE length(VALUE self)
{
xmlNodeSetPtr node_set;
Data_Get_Struct(self, xmlNodeSet, node_set);
if(node_set)
return INT2NUM(node_set->nodeNr);
return INT2NUM(0);
}
/*
* call-seq:
* push(node)
*
* Append +node+ to the NodeSet.
*/
static VALUE push(VALUE self, VALUE rb_node)
{
xmlNodeSetPtr node_set;
xmlNodePtr node;
if(! rb_funcall(rb_node, rb_intern("is_a?"), 1, cNokogiriXmlNode))
rb_raise(rb_eArgError, "node must be a Nokogiri::XML::Node");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_node, xmlNode, node);
xmlXPathNodeSetAdd(node_set, node);
return self;
}
/*
* call-seq:
* delete(node)
*
* Delete +node+ from the Nodeset, if it is a member. Returns the deleted node
* if found, otherwise returns nil.
*/
static VALUE delete(VALUE self, VALUE rb_node)
{
xmlNodeSetPtr node_set ;
xmlNodePtr node ;
if(! rb_funcall(rb_node, rb_intern("is_a?"), 1, cNokogiriXmlNode))
rb_raise(rb_eArgError, "node must be a Nokogiri::XML::Node");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_node, xmlNode, node);
if (xmlXPathNodeSetContains(node_set, node)) {
xmlXPathNodeSetDel(node_set, node);
return rb_node ;
}
return Qnil ;
}
/*
* call-seq:
* &(node_set)
*
* Set Intersection — Returns a new NodeSet containing nodes common to the two NodeSets.
*/
static VALUE intersection(VALUE self, VALUE rb_other)
{
xmlNodeSetPtr node_set;
xmlNodeSetPtr other;
if(! rb_funcall(rb_other, rb_intern("is_a?"), 1, cNokogiriXmlNodeSet))
rb_raise(rb_eArgError, "node_set must be a Nokogiri::XML::NodeSet");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_other, xmlNodeSet, other);
return Nokogiri_wrap_xml_node_set(xmlXPathIntersection(node_set, other));
}
/*
* call-seq:
* include?(node)
*
* Returns true if any member of node set equals +node+.
*/
static VALUE include_eh(VALUE self, VALUE rb_node)
{
xmlNodeSetPtr node_set;
xmlNodePtr node;
if(! rb_funcall(rb_node, rb_intern("is_a?"), 1, cNokogiriXmlNode))
rb_raise(rb_eArgError, "node must be a Nokogiri::XML::Node");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_node, xmlNode, node);
return (xmlXPathNodeSetContains(node_set, node) ? Qtrue : Qfalse);
}
/*
* call-seq:
* +(node_set)
*
* Concatenation - returns a new NodeSet built by concatenating the node set
* with +node_set+ to produce a third NodeSet
*/
static VALUE plus(VALUE self, VALUE rb_other)
{
xmlNodeSetPtr node_set;
xmlNodeSetPtr other;
xmlNodeSetPtr new;
if(! rb_funcall(rb_other, rb_intern("is_a?"), 1, cNokogiriXmlNodeSet))
rb_raise(rb_eArgError, "node_set must be a Nokogiri::XML::NodeSet");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_other, xmlNodeSet, other);
new = xmlXPathNodeSetMerge(NULL, node_set);
new = xmlXPathNodeSetMerge(new, other);
return Nokogiri_wrap_xml_node_set(new);
}
/*
* call-seq:
* -(node_set)
*
* Difference - returns a new NodeSet that is a copy of this NodeSet, removing
* each item that also appears in +node_set+
*/
static VALUE minus(VALUE self, VALUE rb_other)
{
xmlNodeSetPtr node_set;
xmlNodeSetPtr other;
xmlNodeSetPtr new;
int j ;
if(! rb_funcall(rb_other, rb_intern("is_a?"), 1, cNokogiriXmlNodeSet))
rb_raise(rb_eArgError, "node_set must be a Nokogiri::XML::NodeSet");
Data_Get_Struct(self, xmlNodeSet, node_set);
Data_Get_Struct(rb_other, xmlNodeSet, other);
new = xmlXPathNodeSetMerge(NULL, node_set);
for (j = 0 ; j < other->nodeNr ; ++j) {
xmlXPathNodeSetDel(new, other->nodeTab[j]);
}
return Nokogiri_wrap_xml_node_set(new);
}
static VALUE index_at(VALUE self, long offset)
{
xmlNodeSetPtr node_set;
Data_Get_Struct(self, xmlNodeSet, node_set);
if(offset >= node_set->nodeNr || abs(offset) > node_set->nodeNr) return Qnil;
if(offset < 0) offset = offset + node_set->nodeNr;
return Nokogiri_wrap_xml_node(Qnil, node_set->nodeTab[offset]);
}
static VALUE subseq(VALUE self, long beg, long len)
{
int j;
xmlNodeSetPtr node_set;
xmlNodeSetPtr new_set ;
Data_Get_Struct(self, xmlNodeSet, node_set);
if (beg > node_set->nodeNr) return Qnil ;
if (beg < 0 || len < 0) return Qnil ;
new_set = xmlXPathNodeSetCreate(NULL);
for (j = beg ; j < beg+len ; ++j) {
xmlXPathNodeSetAdd(new_set, node_set->nodeTab[j]);
}
return Nokogiri_wrap_xml_node_set(new_set);
}
/*
* call-seq:
* [index] -> Node or nil
* [start, length] -> NodeSet or nil
* [range] -> NodeSet or nil
* slice(index) -> Node or nil
* slice(start, length) -> NodeSet or nil
* slice(range) -> NodeSet or nil
*
* Element reference - returns the node at +index+, or returns a NodeSet
* containing nodes starting at +start+ and continuing for +length+ elements, or
* returns a NodeSet containing nodes specified by +range+. Negative +indices+
* count backward from the end of the +node_set+ (-1 is the last node). Returns
* nil if the +index+ (or +start+) are out of range.
*/
static VALUE slice(int argc, VALUE *argv, VALUE self)
{
VALUE arg ;
long beg, len ;
xmlNodeSetPtr node_set;
Data_Get_Struct(self, xmlNodeSet, node_set);
if (argc == 2) {
beg = NUM2LONG(argv[0]);
len = NUM2LONG(argv[1]);
if (beg < 0) {
beg += node_set->nodeNr ;
}
return subseq(self, beg, len);
}
if (argc != 1) {
rb_scan_args(argc, argv, "11", NULL, NULL);
}
arg = argv[0];
if (FIXNUM_P(arg)) {
return index_at(self, FIX2LONG(arg));
}
/* if arg is Range */
switch (rb_range_beg_len(arg, &beg, &len, node_set->nodeNr, 0)) {
case Qfalse:
break;
case Qnil:
return Qnil;
default:
return subseq(self, beg, len);
}
return index_at(self, NUM2LONG(arg));
}
/*
* call-seq:
* to_a
*
* Return this list as an Array
*/
static VALUE to_array(VALUE self, VALUE rb_node)
{
xmlNodeSetPtr set;
Data_Get_Struct(self, xmlNodeSet, set);
VALUE *elts = calloc((size_t)set->nodeNr, sizeof(VALUE *));
int i;
for(i = 0; i < set->nodeNr; i++) {
if(set->nodeTab[i]->_private) {
elts[i] = (VALUE)set->nodeTab[i]->_private;
} else {
elts[i] = Nokogiri_wrap_xml_node(Qnil, set->nodeTab[i]);
}
}
VALUE list = rb_ary_new4(set->nodeNr, elts);
free(elts);
return list;
}
/*
* call-seq:
* unlink
*
* Unlink this NodeSet and all Node objects it contains from their current context.
*/
static VALUE unlink_nodeset(VALUE self)
{
xmlNodeSetPtr node_set;
int j, nodeNr ;
Data_Get_Struct(self, xmlNodeSet, node_set);
nodeNr = node_set->nodeNr ;
for (j = 0 ; j < nodeNr ; j++) {
VALUE node ;
xmlNodePtr node_ptr;
node = Nokogiri_wrap_xml_node(Qnil, node_set->nodeTab[j]);
rb_funcall(node, rb_intern("unlink"), 0); /* modifies the C struct out from under the object */
Data_Get_Struct(node, xmlNode, node_ptr);
node_set->nodeTab[j] = node_ptr ;
}
return self ;
}
static void deallocate(xmlNodeSetPtr node_set)
{
/*
* xmlXPathFreeNodeSet() contains an implicit assumption that it is being
* called before any of its pointed-to nodes have been free()d. this
* assumption lies in the operation where it dereferences nodeTab pointers
* while searching for namespace nodes to free.
*
* however, since Ruby's GC mechanism cannot guarantee the strict order in
* which ruby objects will be GC'd, nodes may be garbage collected before a
* nodeset containing pointers to those nodes. (this is true regardless of
* how we declare dependencies between objects with rb_gc_mark().)
*
* as a result, xmlXPathFreeNodeSet() will perform unsafe memory operations,
* and calling it would be evil.
*
* on the bright side, though, Nokogiri's API currently does not cause
* namespace nodes to be included in node sets, ever.
*
* armed with that fact, we examined xmlXPathFreeNodeSet() and related libxml
* code and determined that, within the Nokogiri abstraction, we will not
* leak memory if we simply free the node set's memory directly. that's only
* quasi-evil!
*
* there's probably a lesson in here somewhere about intermingling, within a
* single array, structs with different memory-ownership semantics. or more
* generally, a lesson about building an API in C/C++ that does not contain
* assumptions about the strict order in which memory will be released. hey,
* that sounds like a great idea for a blog post! get to it!
*
* "In Valgrind We Trust." seriously.
*/
NOKOGIRI_DEBUG_START(node_set) ;
if (node_set->nodeTab != NULL)
xmlFree(node_set->nodeTab);
xmlFree(node_set);
NOKOGIRI_DEBUG_END(node_set) ;
}
static VALUE allocate(VALUE klass)
{
return Nokogiri_wrap_xml_node_set(xmlXPathNodeSetCreate(NULL));
}
VALUE Nokogiri_wrap_xml_node_set(xmlNodeSetPtr node_set)
{
return Data_Wrap_Struct(cNokogiriXmlNodeSet, 0, deallocate, node_set);
}
VALUE cNokogiriXmlNodeSet ;
void init_xml_node_set(void)
{
VALUE nokogiri = rb_define_module("Nokogiri");
VALUE xml = rb_define_module_under(nokogiri, "XML");
VALUE klass = rb_define_class_under(xml, "NodeSet", rb_cObject);
cNokogiriXmlNodeSet = klass;
rb_define_alloc_func(klass, allocate);
rb_define_method(klass, "length", length, 0);
rb_define_method(klass, "[]", slice, -1);
rb_define_method(klass, "slice", slice, -1);
rb_define_method(klass, "push", push, 1);
rb_define_method(klass, "+", plus, 1);
rb_define_method(klass, "-", minus, 1);
rb_define_method(klass, "unlink", unlink_nodeset, 0);
rb_define_method(klass, "to_a", to_array, 0);
rb_define_method(klass, "dup", duplicate, 0);
rb_define_method(klass, "delete", delete, 1);
rb_define_method(klass, "&", intersection, 1);
rb_define_method(klass, "include?", include_eh, 1);
}
