From 525aa8c4dc3e23f0369c7edb1fb507ecad5f43bf Mon Sep 17 00:00:00 2001 From: Adrian Kummerländer Date: Wed, 23 Apr 2014 21:26:58 +0200 Subject: Fixed xerces DOM construction related memory leaks * Wrapped xerces DOM and support class instances in now DomDocumentGuard scope-guard class * FunctionReadDirectory class contains interal std::stack instance to store DomDocumentGuard instances ** wrapped in std::shared_ptr as FunctionReadDirectory is internally cloned by xalan... ** this is needed as the DOM has to preserved longer than the external function execution scope * Sadly XMLCh xerces strings have to be manually released ** added appropriate xercesc::XMLString::release calls * xalan::XercesDOMWrapperParsedSource does not mirror a given xerces DOM but convert it on instantiation ** this is why there is a dedicated finalize member method in InputXSLT::DomDocumentGuard * In short: I do not like the amount of trickery needed to simply prevent memory leaks in this context ** there sadly doesn't seem to be a substantially easier way to return arbitrary DOM trees from a external function --- CMakeLists.txt | 1 + src/function/read_directory.cc | 48 ++++++++++----------------------------- src/function/read_directory.h | 10 ++++---- src/support/dom_document_guard.cc | 45 ++++++++++++++++++++++++++++++++++++ src/support/dom_document_guard.h | 36 +++++++++++++++++++++++++++++ src/transformer_facade.cc | 2 ++ 6 files changed, 101 insertions(+), 41 deletions(-) create mode 100644 src/support/dom_document_guard.cc create mode 100644 src/support/dom_document_guard.h diff --git a/CMakeLists.txt b/CMakeLists.txt index 915a05d..94ade96 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -18,6 +18,7 @@ add_executable( src/function/read_xml_file.cc src/function/read_directory.cc src/support/filesystem_context.cc + src/support/dom_document_guard.cc ) target_link_libraries( diff --git a/src/function/read_directory.cc b/src/function/read_directory.cc index a4284c0..6d643da 100644 --- a/src/function/read_directory.cc +++ b/src/function/read_directory.cc @@ -1,25 +1,16 @@ #include "read_directory.h" -#include -#include - #include #include #include #include #include -#include - namespace InputXSLT { FunctionReadDirectory::FunctionReadDirectory(const FilesystemContext& context): fs_context_(context), - parser_() { } - -FunctionReadDirectory::FunctionReadDirectory(const FunctionReadDirectory& src): - fs_context_(src.fs_context_), - parser_() { } + documents_(new std::stack()) { } xalan::XObjectPtr FunctionReadDirectory::execute( xalan::XPathExecutionContext& executionContext, @@ -35,44 +26,29 @@ xalan::XObjectPtr FunctionReadDirectory::execute( this->generalError(executionContext, context, locator); } - xercesc::DOMDocument* const inputDom( - xercesc::DOMImplementation::getImplementation()->createDocument( - nullptr, xercesc::XMLString::transcode("content"), nullptr - ) - ); + this->documents_->emplace("content"); + DomDocumentGuard& domDocument = this->documents_->top(); - xercesc::DOMNode* const rootNode = inputDom->getDocumentElement(); + xercesc::DOMNode* const rootNode = domDocument->getDocumentElement(); this->fs_context_.iterate( arguments[0]->str(), - [&inputDom, &rootNode](const boost::filesystem::path& p) { - xercesc::DOMNode* const fileNode = inputDom->createElement( - xercesc::XMLString::transcode("file") - ); + [&domDocument, &rootNode](const boost::filesystem::path& p) { + XMLCh* buffer = xercesc::XMLString::transcode("file"); + xercesc::DOMNode* const fileNode = domDocument->createElement(buffer); + xercesc::XMLString::release(&buffer); - xercesc::DOMText* const textNode = inputDom->createTextNode( - xercesc::XMLString::transcode(p.filename().string().data()) - ); + buffer = xercesc::XMLString::transcode(p.filename().string().data()); + xercesc::DOMText* const textNode = domDocument->createTextNode(buffer); + xercesc::XMLString::release(&buffer); fileNode->appendChild(textNode); rootNode->appendChild(fileNode); }); - - xalan::XercesDOMSupport domSupport(this->parser_); - - xalan::XercesDOMWrapperParsedSource* const parsedSource( - new xalan::XercesDOMWrapperParsedSource( - inputDom, - this->parser_, - domSupport - ) - ); - return executionContext.getXObjectFactory().createNodeSet( - parsedSource->getDocument() + domDocument.finalize() ); - } FunctionReadDirectory* FunctionReadDirectory::clone( diff --git a/src/function/read_directory.h b/src/function/read_directory.h index e7ee0c4..3c55591 100644 --- a/src/function/read_directory.h +++ b/src/function/read_directory.h @@ -6,19 +6,18 @@ #include #include -#include - -#include +#include +#include #include "common.h" #include "support/filesystem_context.h" +#include "support/dom_document_guard.h" namespace InputXSLT { class FunctionReadDirectory : public xalan::Function { public: FunctionReadDirectory(const FilesystemContext&); - FunctionReadDirectory(const FunctionReadDirectory&); virtual xalan::XObjectPtr execute( xalan::XPathExecutionContext&, @@ -34,7 +33,8 @@ class FunctionReadDirectory : public xalan::Function { private: const FilesystemContext& fs_context_; - mutable xalan::XercesParserLiaison parser_; + + std::shared_ptr> documents_; const xalan::XalanDOMString& getError(xalan::XalanDOMString&) const; diff --git a/src/support/dom_document_guard.cc b/src/support/dom_document_guard.cc new file mode 100644 index 0000000..a83345f --- /dev/null +++ b/src/support/dom_document_guard.cc @@ -0,0 +1,45 @@ +#include "support/dom_document_guard.h" + +#include +#include + +namespace InputXSLT { + +DomDocumentGuard::DomDocumentGuard(const std::string& rootNode): + parser_(), + dom_support_(parser_), + root_node_name_( + xercesc::XMLString::transcode(rootNode.data()) + ), + document_( + xercesc::DOMImplementation::getImplementation()->createDocument( + nullptr, + root_node_name_, + nullptr + ) + ), + parsed_source_() { } + +DomDocumentGuard::~DomDocumentGuard() { + xercesc::XMLString::release(&this->root_node_name_); + + this->document_->release(); +} + +xercesc::DOMDocument* DomDocumentGuard::operator->() { + return this->document_; +} + +xalan::XalanDocument* DomDocumentGuard::finalize() { + this->parsed_source_.reset( + new xalan::XercesDOMWrapperParsedSource( + document_, + parser_, + dom_support_ + ) + ); + + return this->parsed_source_->getDocument(); +} + +} diff --git a/src/support/dom_document_guard.h b/src/support/dom_document_guard.h new file mode 100644 index 0000000..decca01 --- /dev/null +++ b/src/support/dom_document_guard.h @@ -0,0 +1,36 @@ +#ifndef INPUTXSLT_SRC_SUPPORT_DOM_DOCUMENT_GUARD_H_ +#define INPUTXSLT_SRC_SUPPORT_DOM_DOCUMENT_GUARD_H_ + +#include +#include +#include + +#include + +#include +#include + +#include "common.h" + +namespace InputXSLT { + +class DomDocumentGuard { + public: + DomDocumentGuard(const std::string&); + ~DomDocumentGuard(); + + xercesc::DOMDocument* operator->(); + xalan::XalanDocument* finalize(); + + private: + xalan::XercesParserLiaison parser_; + xalan::XercesDOMSupport dom_support_; + XMLCh* root_node_name_; + xercesc::DOMDocument* const document_; + std::unique_ptr parsed_source_; + +}; + +} + +#endif // INPUTXSLT_SRC_SUPPORT_DOM_DOCUMENT_GUARD_H_ diff --git a/src/transformer_facade.cc b/src/transformer_facade.cc index 01314cd..fbf604c 100644 --- a/src/transformer_facade.cc +++ b/src/transformer_facade.cc @@ -59,6 +59,8 @@ int TransformerFacade::execute( domSupport ); + inputDom->release(); + xalan::XSLTInputSource transform(transformation.data()); xalan::XSLTResultTarget output(target.data()); -- cgit v1.2.3