Nokogiri::HTML::SAX::ParserContext

static VALUE parse_file(VALUE klass, VALUE filename, VALUE encoding)
{
  htmlParserCtxtPtr ctxt = htmlCreateFileParserCtxt(
      StringValuePtr(filename),
      StringValuePtr(encoding)
  );
  return Data_Wrap_Struct(klass, NULL, deallocate, ctxt);
}

static VALUE parse_memory(VALUE klass, VALUE data, VALUE encoding)
{
  htmlParserCtxtPtr ctxt;

  if(NIL_P(data)) rb_raise(rb_eArgError, "data cannot be nil");
  if(!(int)RSTRING_LEN(data))
    rb_raise(rb_eRuntimeError, "data cannot be empty");

  ctxt = htmlCreateMemoryParserCtxt(
      StringValuePtr(data),
      (int)RSTRING_LEN(data)
  );

  if(RTEST(encoding)) {
    xmlCharEncodingHandlerPtr enc = xmlFindCharEncodingHandler(StringValuePtr(encoding));
    if(enc != NULL) {
      xmlSwitchToEncoding(ctxt, enc);
      if(ctxt->errNo == XML_ERR_UNSUPPORTED_ENCODING) {
        rb_raise(rb_eRuntimeError, "Unsupported encoding %s",
            StringValuePtr(encoding));
      }
    }
  }

  return Data_Wrap_Struct(klass, NULL, deallocate, ctxt);
}

# File lib/nokogiri/html/sax/parser_context.rb, line 9
def self.new thing, encoding = 'UTF-8'
  [:read, :close].all? { |x| thing.respond_to?(x) } ?  super :
    memory(thing, encoding)
end

static VALUE parse_with(VALUE self, VALUE sax_handler)
{
  htmlParserCtxtPtr ctxt;
  htmlSAXHandlerPtr sax;

  if(!rb_obj_is_kind_of(sax_handler, cNokogiriXmlSaxParser))
    rb_raise(rb_eArgError, "argument must be a Nokogiri::XML::SAX::Parser");

  Data_Get_Struct(self, htmlParserCtxt, ctxt);
  Data_Get_Struct(sax_handler, htmlSAXHandler, sax);

  /* Free the sax handler since we'll assign our own */
  if(ctxt->sax && ctxt->sax != (xmlSAXHandlerPtr)&xmlDefaultSAXHandler)
    xmlFree(ctxt->sax);

  ctxt->sax = sax;
  ctxt->userData = (void *)NOKOGIRI_SAX_TUPLE_NEW(ctxt, sax_handler);

  htmlParseDocument(ctxt);

  if(NULL != ctxt->myDoc) xmlFreeDoc(ctxt->myDoc);

  NOKOGIRI_SAX_TUPLE_DESTROY(ctxt->userData);
  return self;
}