ensure invalidated values are removed

When a node receives an InvalidateCache signal, it will
automatically signal its outputs to discard any cached values in
the invalidated time range

app/node/node.cpp

@@ -83,6 +83,13 @@ void Node::InvalidateCache(const rational &start_range, const rational &end_rang
 {
   Q_UNUSED(from)
 
+  foreach (NodeParam* param, params_) {
+    if (param->type() == NodeParam::kOutput) {
+      NodeOutput* output = static_cast<NodeOutput*>(param);
+      output->drop_cached_values_overlapping(TimeRange(start_range, end_range));
+    }
+  }
+
   SendInvalidateCache(start_range, end_range);
 }
 

app/node/output.cpp

@@ -58,3 +58,16 @@ void NodeOutput::drop_cached_values()
 {
   cached_values_.clear();
 }
+
+void NodeOutput::drop_cached_values_overlapping(const TimeRange &time)
+{
+  QHash<TimeRange, QVariant>::iterator i = cached_values_.begin();
+
+  while (i != cached_values_.end()) {
+    if (i.key().OverlapsWith(time)) {
+      i = cached_values_.erase(i);
+    } else {
+      i++;
+    }
+  }
+}

app/node/output.h

@@ -46,6 +46,7 @@ public:
   QVariant get_cached_value(const TimeRange& time);
   void cache_value(const TimeRange& time, const QVariant& value);
   void drop_cached_values();
+  void drop_cached_values_overlapping(const TimeRange& time);
 
 private:
   QHash<TimeRange, QVariant> cached_values_;