nodes: implemented infrastructure for caching any node

Not accessible through UI yet, but ported Footage node to it
(previously we used a hack to ensure Footage textures were
cached, now it's a formal infrastructure).

app/node/node.cpp

@@ -48,7 +48,8 @@ Node::Node(bool create_default_output) :
   override_color_(-1),
   last_change_time_(0),
   folder_(nullptr),
-  operation_stack_(0)
+  operation_stack_(0),
+  cache_result_(false)
 {
   if (create_default_output) {
     AddOutput();

app/node/node.h

@@ -756,6 +756,16 @@ public:
     folder_ = folder;
   }
 
+  bool GetCacheTextures() const
+  {
+    return cache_result_;
+  }
+
+  void SetCacheTextures(bool e)
+  {
+    cache_result_ = e;
+  }
+
   static const QString kDefaultOutput;
 
 protected:
@@ -1191,6 +1201,8 @@ private:
 
   int operation_stack_;
 
+  bool cache_result_;
+
 private slots:
   /**
    * @brief Slot when a keyframe's time changes to keep the keyframes correctly sorted by time

app/node/project/footage/footage.cpp

@@ -48,6 +48,8 @@ Footage::Footage(const QString &filename) :
   Clear();
 
   set_filename(filename);
+
+  SetCacheTextures(true);
 }
 
 void Footage::Retranslate()

app/node/traverser.cpp

@@ -22,6 +22,7 @@
 
 #include "node.h"
 #include "render/job/footagejob.h"
+#include "render/rendermanager.h"
 
 namespace olive {
 
@@ -110,7 +111,7 @@ NodeValueTable NodeTraverser::GenerateTable(const Node *n, const QString& output
   // By this point, the node should have all the inputs it needs to render correctly
   NodeValueTable table = n->Value(output, database);
 
-  PostProcessTable(n, range, table);
+  PostProcessTable(n, output, range, table);
 
   return table;
 }
@@ -171,10 +172,15 @@ QVariant NodeTraverser::ProcessFrameGeneration(const Node *node, const GenerateJ
   return QVariant();
 }
 
-QVariant NodeTraverser::GetCachedFrame(const Node *node, const rational &time)
+void NodeTraverser::SaveCachedTexture(const QByteArray &hash, const QVariant &texture)
 {
-  Q_UNUSED(node)
-  Q_UNUSED(time)
+  Q_UNUSED(hash)
+  Q_UNUSED(texture)
+}
+
+QVariant NodeTraverser::GetCachedTexture(const QByteArray& hash)
+{
+  Q_UNUSED(hash)
 
   return QVariant();
 }
@@ -190,17 +196,23 @@ void NodeTraverser::AddGlobalsToDatabase(NodeValueDatabase &db, const TimeRange&
   db.Insert(QStringLiteral("global"), global);
 }
 
-void NodeTraverser::PostProcessTable(const Node *node, const TimeRange &range, NodeValueTable &output_params)
+void NodeTraverser::PostProcessTable(const Node *node, const QString& output, const TimeRange &range, NodeValueTable &output_params)
 {
   bool got_cached_frame = false;
+  QByteArray cached_node_hash;
 
   // Convert footage to image/sample buffers
-  QVariant cached_frame = GetCachedFrame(node, range.in());
-  if (!cached_frame.isNull()) {
-    output_params.Push(NodeValue::kTexture, cached_frame, node);
+  if (CanCacheFrames() && node->GetCacheTextures()) {
+    // This node is set to cache the result, see if we can retrieved a previously cached version
+    cached_node_hash = RenderManager::Hash(node, output, GetCacheVideoParams(), range.in());
 
-    // No more to do here
-    got_cached_frame = true;
+    QVariant cached_frame = GetCachedTexture(cached_node_hash);
+    if (!cached_frame.isNull()) {
+      output_params.Push(NodeValue::kTexture, cached_frame, node);
+
+      // No more to do here
+      got_cached_frame = true;
+    }
   }
 
   // Strip out any jobs or footage
@@ -285,6 +297,11 @@ void NodeTraverser::PostProcessTable(const Node *node, const TimeRange &range, N
       output_params.Push(NodeValue::kSamples, value, node);
     }
   }
+
+  if (CanCacheFrames() && node->GetCacheTextures() && !got_cached_frame) {
+    // Save cached texture
+    SaveCachedTexture(cached_node_hash, output_params.Get(NodeValue::kTexture));
+  }
 }
 
 }

app/node/traverser.h

@@ -59,7 +59,19 @@ protected:
 
   virtual QVariant ProcessFrameGeneration(const Node *node, const GenerateJob& job);
 
-  virtual QVariant GetCachedFrame(const Node *node, const rational &time);
+  virtual QVariant GetCachedTexture(const QByteArray& hash);
+
+  virtual void SaveCachedTexture(const QByteArray& hash, const QVariant& texture);
+
+  virtual bool CanCacheFrames()
+  {
+    return false;
+  }
+
+  virtual VideoParams GetCacheVideoParams()
+  {
+    return VideoParams();
+  }
 
   void AddGlobalsToDatabase(NodeValueDatabase& db, const TimeRange &range) const;
 
@@ -69,7 +81,7 @@ protected:
   }
 
 private:
-  void PostProcessTable(const Node *node, const TimeRange &range, NodeValueTable &output_params);
+  void PostProcessTable(const Node *node, const QString &output, const TimeRange &range, NodeValueTable &output_params);
 
 };