Revamped DomDocumentCache with regard to thread safety

* DomDocumentCache::item class now is _finalized_ by default and doesn't perform document instantiation, just lifetime management
** xercesc::DOMDocument is instantiated inside the external function implementations and committed to the document cache for conversion to a xalan document
* added mutex with scoped lock to prevent concurrent write access to the std::unordered_map contained withing DomDocumentCache
* functionality of the _get_ member method was split into _get_ and _create_
** added typedef for std::pair specialization type "optional_item" that functions as the return value of _create_ and _get_
* "locator->getSystemId()" was leaking memory as xerces doesn't manage the lifetime of the returned heap-allocated char array
** analog to XMLCh* strings
** transformed XercesStringGuard into template class to be instantiated on either XMLCh or char

1 files changed, 8 insertions, 35 deletions

diff --git a/src/support/dom/document_cache_item.cc b/src/support/dom/document_cache_item.cc
index 8cc1c24..9798bfa 100644
--- a/src/support/dom/document_cache_item.cc
+++ b/src/support/dom/document_cache_item.cc
@@ -1,50 +1,23 @@
 #include "support/dom/document_cache_item.h"
 
-#include <xercesc/dom/DOMImplementation.hpp>
-#include <xercesc/util/XMLString.hpp>
-
-#include "support/xerces_string_guard.h"
-
 namespace InputXSLT {
 
-DomDocumentCache::item::item(const std::string& rootNode):
+DomDocumentCache::item::item(xercesc::DOMDocument* document):
 	parser_(),
 	dom_support_(parser_),
-	document_(
-		xercesc::DOMImplementation::getImplementation()->createDocument(
-			nullptr,
-			*XercesStringGuard(rootNode),
-			nullptr
-		)
-	),
-	parsed_source_() { }
+	document_(document),
+	parsed_source_(
+		document_,
+		parser_,
+		dom_support_
+	) { }
 
 DomDocumentCache::item::~item() {
 	this->document_->release();
 }
 
-bool DomDocumentCache::item::isFinalized() const {
-	return static_cast<bool>(this->parsed_source_);
-}
-
-xercesc::DOMDocument* DomDocumentCache::item::getXercesDocument() const {
-	return this->document_;
-}
-
 xalan::XalanDocument* DomDocumentCache::item::getXalanDocument() {
-	if ( this->parsed_source_ ) {
-		return this->parsed_source_->getDocument();
-	} else {
-		this->parsed_source_.reset(
-			new xalan::XercesDOMWrapperParsedSource(
-					document_,
-					parser_,
-					dom_support_
-			)
-		);
-
-		return this->parsed_source_->getDocument();
-	}
+	return this->parsed_source_.getDocument();
 }
 
 }