BugFix: interrupting recursive session loading

Prevent crash on  recursive (infinite) loading of session file (containing itself).

Mixer.cpp

@@ -948,7 +948,7 @@ void Mixer::load(const std::string& filename)
     if (sessionLoaders_.empty()) {
         // Start async thread for loading the session
         // Will be obtained in the future in update()
-        sessionLoaders_.emplace_back( std::async(std::launch::async, Session::load, filename) );
+        sessionLoaders_.emplace_back( std::async(std::launch::async, Session::load, filename, 0) );
     }
 #else
     set( Session::load(filename) );
@@ -986,7 +986,7 @@ void Mixer::import(const std::string& filename)
     if (sessionImporters_.empty()) {
         // Start async thread for loading the session
         // Will be obtained in the future in update()
-        sessionImporters_.emplace_back( std::async(std::launch::async, Session::load, filename) );
+        sessionImporters_.emplace_back( std::async(std::launch::async, Session::load, filename, 0) );
     }
 #else
     merge( Session::load(filename) );

SearchVisitor.cpp

@@ -1,6 +1,11 @@
+#include <algorithm>
+
 #include "SearchVisitor.h"
 
 #include "Scene.h"
+#include "MediaSource.h"
+#include "Session.h"
+#include "SessionSource.h"
 
 SearchVisitor::SearchVisitor(Node *node) : Visitor(), node_(node), found_(false)
 {
@@ -42,12 +47,11 @@ void SearchVisitor::visit(Scene &n)
 
 
 
-SearchFileVisitor::SearchFileVisitor(std::string filename) : Visitor(), filename_(filename), found_(false)
+SearchFileVisitor::SearchFileVisitor() : Visitor()
 {
 
 }
 
-
 void SearchFileVisitor::visit(Node &n)
 {
 
@@ -55,13 +59,8 @@ void SearchFileVisitor::visit(Node &n)
 
 void SearchFileVisitor::visit(Group &n)
 {
-    if (found_)
-        return;
-
     for (NodeSet::iterator node = n.begin(); node != n.end(); node++) {
         (*node)->accept(*this);
-        if (found_)
-            break;
     }
 }
 
@@ -81,10 +80,29 @@ void SearchFileVisitor::visit(Scene &n)
 
 void SearchFileVisitor::visit (MediaSource& s)
 {
-
+    filenames_.push_back( s.path() );
 }
 
 void SearchFileVisitor::visit (SessionFileSource& s)
 {
 
+    filenames_.push_back( s.path() );
 }
+
+std::list<std::string> SearchFileVisitor::parse (Session *se)
+{
+    SearchFileVisitor sv;
+
+    for (auto iter = se->begin(); iter != se->end(); iter++){
+        (*iter)->accept(sv);
+    }
+
+    return sv.filenames();
+}
+
+bool SearchFileVisitor::find (Session *se, std::string path)
+{
+    std::list<std::string> filenames = parse (se);
+    return std::find(filenames.begin(), filenames.end(), path) != filenames.end();
+}
+

SearchVisitor.h

@@ -1,9 +1,12 @@
 #ifndef SEARCHVISITOR_H
 #define SEARCHVISITOR_H
 
+#include <list>
 #include <string>
 #include "Visitor.h"
 
+class Session;
+
 class SearchVisitor: public Visitor
 {
     Node *node_;
@@ -15,33 +18,35 @@ public:
     inline Node *node() const { return found_ ? node_ : nullptr; }
 
     // Elements of Scene
-    void visit(Scene& n) override;
-    void visit(Node& n) override;
-    void visit(Primitive&) override {}
-    void visit(Group& n) override;
-    void visit(Switch& n) override;
+    void visit (Scene& n) override;
+    void visit (Node& n) override;
+    void visit (Primitive&) override {}
+    void visit (Group& n) override;
+    void visit (Switch& n) override;
 
 };
 
 class SearchFileVisitor: public Visitor
 {
-    std::string filename_;
-    bool found_;
+    std::list<std::string> filenames_;
 
 public:
-    SearchFileVisitor(std::string filename);
-    inline bool found() const { return found_; }
+    SearchFileVisitor();
+    inline std::list<std::string> filenames() const { return filenames_; }
 
     // Elements of Scene
-    void visit(Scene& n) override;
-    void visit(Node& n) override;
-    void visit(Primitive&) override {}
-    void visit(Group& n) override;
-    void visit(Switch& n) override;
+    void visit (Scene& n) override;
+    void visit (Node& n) override;
+    void visit (Primitive&) override {}
+    void visit (Group& n) override;
+    void visit (Switch& n) override;
 
     // Sources
     void visit (MediaSource& s) override;
     void visit (SessionFileSource& s) override;
+
+    static std::list<std::string> parse (Session *se);
+    static bool find (Session *se, std::string path);
 };
 
 #endif // SEARCHVISITOR_H

Session.cpp

@@ -4,7 +4,6 @@
 #include "Settings.h"
 #include "FrameBuffer.h"
 #include "Session.h"
-#include "GarbageVisitor.h"
 #include "FrameGrabber.h"
 #include "SessionCreator.h"
 #include "SessionSource.h"
@@ -323,9 +322,9 @@ void Session::unlock()
 }
 
 
-Session *Session::load(const std::string& filename)
+Session *Session::load(const std::string& filename, uint recursion)
 {
-    SessionCreator creator;
+    SessionCreator creator(recursion);
     creator.load(filename);
 
     return creator.session();

Session.h

@@ -14,7 +14,7 @@ public:
     Session();
     ~Session();
 
-    static Session *load(const std::string& filename);
+    static Session *load(const std::string& filename, uint recursion = 0);
 
     // add given source into the session
     SourceList::iterator addSource (Source *s);

SessionCreator.cpp

@@ -52,7 +52,7 @@ std::string SessionCreator::info(const std::string& filename)
     return ret;
 }
 
-SessionCreator::SessionCreator(): SessionLoader(nullptr)
+SessionCreator::SessionCreator(uint recursion): SessionLoader(nullptr, recursion)
 {
 
 }
@@ -108,7 +108,7 @@ void SessionCreator::loadConfig(XMLElement *viewsNode)
     }
 }
 
-SessionLoader::SessionLoader(Session *session): Visitor(), session_(session)
+SessionLoader::SessionLoader(Session *session, uint recursion): Visitor(), session_(session), recursion_(recursion)
 {
 
 }
@@ -117,6 +117,11 @@ void SessionLoader::load(XMLElement *sessionNode)
 {
     sources_id_.clear();
 
+    if (recursion_ > MAX_SESSION_LEVEL) {
+        Log::Warning("Recursive or imbricated sessions detected! Interrupting loading after %d iterations.\n", MAX_SESSION_LEVEL);
+        return;
+    }
+
     if (sessionNode != nullptr && session_ != nullptr) {
 
         XMLElement* sourceNode = sessionNode->FirstChildElement("Source");
@@ -534,11 +539,11 @@ void SessionLoader::visit (SessionFileSource& s)
     XMLElement* pathNode = xmlCurrent_->FirstChildElement("path");
     if (pathNode) {
         std::string path = std::string ( pathNode->GetText() );
+
         // load only new files
         if ( path != s.path() )
-            s.load(path);
+            s.load(path, recursion_ + 1);
     }
-
 }
 
 void SessionLoader::visit (SessionGroupSource& s)
@@ -550,10 +555,9 @@ void SessionLoader::visit (SessionGroupSource& s)
     XMLElement* sessionGroupNode = xmlCurrent_->FirstChildElement("Session");
     if (sessionGroupNode) {
         // load session inside group
-        SessionLoader grouploader( s.session() );
+        SessionLoader grouploader( s.session(), recursion_ + 1 );
         grouploader.load( sessionGroupNode );
     }
-
 }
 
 void SessionLoader::visit (RenderSource& s)

SessionCreator.h

@@ -13,7 +13,7 @@ class SessionLoader : public Visitor {
 
 public:
 
-    SessionLoader(Session *session);
+    SessionLoader(Session *session, uint recursion = 0);
     inline Session *session() const { return session_; }
 
     void load(tinyxml2::XMLElement *sessionNode);
@@ -58,6 +58,7 @@ protected:
     tinyxml2::XMLElement *xmlCurrent_;
     Session *session_;
     std::list<uint64_t> sources_id_;
+    uint recursion_;
 
     static void XMLToNode(tinyxml2::XMLElement *xml, Node &n);
 };
@@ -69,7 +70,7 @@ class SessionCreator : public SessionLoader {
     void loadConfig(tinyxml2::XMLElement *viewsNode);
 
 public:
-    SessionCreator();
+    SessionCreator(uint recursion = 0);
 
     void load(const std::string& filename);
 

SessionSource.cpp

@@ -128,7 +128,7 @@ SessionFileSource::SessionFileSource() : SessionSource(), path_("")
     wait_for_sources_ = false;
 }
 
-void SessionFileSource::load(const std::string &p)
+void SessionFileSource::load(const std::string &p, uint recursion)
 {
     path_ = p;
 
@@ -142,10 +142,11 @@ void SessionFileSource::load(const std::string &p)
     if ( path_.empty() ) {
         // empty session
         session_ = new Session;
+        Log::Warning("Empty Session filename provided.");
     }
     else {
         // launch a thread to load the session file
-        sessionLoader_ = std::async(std::launch::async, Session::load, path_);
+        sessionLoader_ = std::async(std::launch::async, Session::load, path_, recursion);
         Log::Notify("Opening %s", p.c_str());
     }
 }

SessionSource.h

@@ -35,7 +35,7 @@ public:
     void accept (Visitor& v) override;
 
     // SessionFile Source specific interface
-    void load(const std::string &p = "");
+    void load(const std::string &p = "", uint recursion = 0);
 
     inline std::string path() const { return path_; }
     glm::ivec2 icon() const override { return glm::ivec2(2, 16); }

SessionVisitor.cpp

@@ -433,9 +433,10 @@ void SessionVisitor::visit (SessionGroupSource& s)
     XMLElement *rootgroup = xmlDoc_->NewElement("Session");
     xmlCurrent_->InsertEndChild(rootgroup);
 
+    for (auto iter = se->begin(); iter != se->end(); iter++){
         setRoot(rootgroup);
-    for (auto iter = se->begin(); iter != se->end(); iter++, setRoot(rootgroup) )
         (*iter)->accept(*this);
+    }
 
 }
 

defines.h

@@ -9,6 +9,7 @@
 #define XML_VERSION_MAJOR 0
 #define XML_VERSION_MINOR 2
 #define MAX_RECENT_HISTORY 20
+#define MAX_SESSION_LEVEL 3
 
 #define MINI(a, b)  (((a) < (b)) ? (a) : (b))
 #define MAXI(a, b)  (((a) > (b)) ? (a) : (b))