add nf7::Node::Meta and improve nf7::Node interface

common/node.hh

@@ -28,6 +28,24 @@ class Node : public File::Interface {
   };
   using Flags = uint8_t;
 
+  struct Meta final {
+   public:
+    Meta() = default;
+    Meta(std::vector<std::string>&& i, std::vector<std::string>&& o) noexcept :
+        inputs(std::move(i)), outputs(std::move(o)) {
+    }
+    Meta(const std::vector<std::string>& i, const std::vector<std::string>& o) noexcept :
+        inputs(i), outputs(o) {
+    }
+
+    Meta(const Meta&) = default;
+    Meta(Meta&&) = default;
+    Meta& operator=(const Meta&) = default;
+    Meta& operator=(Meta&&) = default;
+
+    std::vector<std::string> inputs, outputs;
+  };
+
   static void ValidateSockets(std::span<const std::string> v) {
     for (auto itr = v.begin(); itr < v.end(); ++itr) {
       if (v.end() != std::find(itr+1, v.end(), *itr)) {
@@ -50,13 +68,12 @@ class Node : public File::Interface {
   virtual void UpdateNode(Editor&) noexcept { }
   virtual void UpdateMenu(Editor&) noexcept { }
 
-  // The returned span is alive until next operation to the file.
+  // don't call too often because causes heap allocation
-  virtual std::span<const std::string> GetInputs() const noexcept = 0;
+  virtual Meta GetMeta() const noexcept = 0;
-  virtual std::span<const std::string> GetOutputs() const noexcept = 0;
 
   Flags flags() const noexcept { return flags_; }
 
- protected:
+ private:
   Flags flags_;
 };
 

file/audio_device.cc

@@ -122,13 +122,12 @@ class Device final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"info", "mix", "peek"};
+    static const std::vector<std::string> kInputs = {};
-    return kInputs;
+    return {
-  }
+      {"info", "mix", "peek"},
-  std::span<const std::string> GetOutputs() const noexcept override {
+      {"result"}
-    static const std::vector<std::string> kOutputs = {"result"};
+    };
-    return kOutputs;
   }
 
   nf7::Future<std::shared_ptr<Instance>> Build() noexcept;

file/font_face.cc

@@ -106,16 +106,13 @@ class FontFace final : public nf7::FileBase,
     return {std::current_exception()};
   }
 
-  std::span<const std::string> GetInputs() const noexcept override {
-    static const std::vector<std::string> kInputs = {"command"};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    static const std::vector<std::string> kOutputs = {"result"};
-    return kOutputs;
-  }
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
+  nf7::Node::Meta GetMeta() const noexcept override {
+    return {
+      {"command"}, {"result"},
+    };
+  }
 
   void UpdateMenu() noexcept override;
   void UpdateTooltip() noexcept override;

file/gl_obj.cc

@@ -140,11 +140,8 @@ class ObjBase : public nf7::FileBase,
       const std::shared_ptr<nf7::Node::Lambda>& parent) noexcept override {
     return std::make_shared<Lambda>(*this, parent);
   }
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    return T::kInputs;
+    return {T::kInputs, T::kOutputs};
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return T::kOutputs;
   }
 
   ResourceFuture Create() noexcept final {

file/luajit_node.cc

@@ -90,11 +90,8 @@ class Node final : public nf7::FileBase,
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
 
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    return mem_->inputs;
+    return nf7::Node::Meta {mem_->inputs, mem_->outputs};
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return mem_->outputs;
   }
 
   nf7::Future<std::shared_ptr<nf7::luajit::Ref>> Build() noexcept;

file/node_imm.cc

@@ -65,13 +65,8 @@ class Imm final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"in"};
+    return {{"in"}, {"out"}};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    static const std::vector<std::string> kOutputs = {"out"};
-    return kOutputs;
   }
 
   void UpdateNode(nf7::Node::Editor&) noexcept override;

file/node_network.cc

@@ -1,5 +1,6 @@
 #include <algorithm>
 #include <cstdint>
+#include <cstdlib>
 #include <memory>
 #include <optional>
 #include <span>
@@ -163,12 +164,8 @@ class Network final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-
+  nf7::Node::Meta GetMeta() const noexcept override {
-  std::span<const std::string> GetInputs() const noexcept override {
+    return {mem_->inputs, mem_->outputs};
-    return mem_->inputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return mem_->outputs;
   }
 
   File::Interface* interface(const std::type_info& t) noexcept override {
@@ -327,6 +324,7 @@ class Network::Item final {
   nf7::Env& env() const noexcept { return file_->env(); }
   nf7::File& file() const noexcept { return *file_; }
   nf7::Node& node() const noexcept { return *node_; }
+  const nf7::Node::Meta& meta() const noexcept { return meta_; }
 
   InternalNode* inode() const noexcept { return inode_; }
   InternalNode::Flags iflags() const noexcept { return inode_? inode_->flags(): 0; }
@@ -337,6 +335,7 @@ class Network::Item final {
   std::unique_ptr<nf7::File> file_;
   nf7::Node*      node_;
   InternalNode*   inode_;
+  nf7::Node::Meta meta_;
 
   std::optional<nf7::MementoRecorder> mem_;
 
@@ -366,6 +365,8 @@ class Network::Item final {
     mem_.emplace(file_->interface<nf7::Memento>());
 
     inode_ = file_->interface<Network::InternalNode>();
+    meta_  = node_->GetMeta();
+
     prev_pos_ = pos_;
   }
 };
@@ -717,12 +718,8 @@ class Network::Initiator final : public nf7::File,
     };
     return std::make_shared<Emitter>(*this, parent);
   }
-  std::span<const std::string> GetInputs() const noexcept {
+  nf7::Node::Meta GetMeta() const noexcept {
-    return {};
+    return {{}, {"out"}};
-  }
-  std::span<const std::string> GetOutputs() const noexcept {
-    static const std::vector<std::string> kOutputs = {"out"};
-    return kOutputs;
   }
 
   void UpdateNode(nf7::Node::Editor& ed) noexcept override;
@@ -769,20 +766,14 @@ class Network::Terminal : public nf7::FileBase,
       const std::shared_ptr<nf7::Node::Lambda>& parent) noexcept override {
     return std::make_shared<Emitter>(*this, parent);
   }
-
+  nf7::Node::Meta GetMeta() const noexcept override {
-  std::span<const std::string> GetInputs() const noexcept override {
+    switch (data().type) {
-    if (data().type == kOutput) {
+    case kInput:
-      static const std::vector<std::string> kInputs = {"in"};
+      return {{}, {"out"}};
-      return kInputs;
+    case kOutput:
+      return {{"in"}, {}};
     }
-    return {};
+    std::abort();
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    if (data().type == kInput) {
-      static const std::vector<std::string> kInputs = {"out"};
-      return kInputs;
-    }
-    return {};
   }
 
   void UpdateNode(nf7::Node::Editor&) noexcept override;
@@ -867,7 +858,7 @@ void Network::Sanitize() {
   // remove expired links
   for (const auto& item : items_) {
     auto cmd = links_.CreateCommandToRemoveExpired(
-        item->id(), item->node().GetInputs(), item->node().GetOutputs());
+        item->id(), item->meta().inputs, item->meta().outputs);
     if (cmd) {
       cmd->Apply();
     }
@@ -937,7 +928,6 @@ void Network::Item::Detach() noexcept {
 }
 void Network::Item::Watcher::Handle(const File::Event& ev) noexcept {
   auto& item = *owner_;
-  auto& node = item.node();
 
   switch (ev.type) {
   case File::Event::kUpdate:
@@ -945,8 +935,10 @@ void Network::Item::Watcher::Handle(const File::Event& ev) noexcept {
       auto& net  = *item.owner_;
       net.Touch();
 
-      const auto inputs  = node.GetInputs();
+      // update metadata
-      const auto outputs = node.GetOutputs();
+      item.meta_ = item.node().GetMeta();
+      const auto& inputs  = item.meta().inputs;
+      const auto& outputs = item.meta().outputs;
 
       // check expired sockets
       if (auto cmd = net.links_.CreateCommandToRemoveExpired(item.id(), inputs, outputs)) {
@@ -1195,9 +1187,9 @@ void Network::Item::UpdateNode(Node::Editor& ed) noexcept {
       node_->UpdateNode(ed);
     } else {
       ImGui::TextUnformatted(file_->type().name().c_str());
-      nf7::gui::NodeInputSockets(node_->GetInputs());
+      nf7::gui::NodeInputSockets(meta_.inputs);
       ImGui::SameLine();
-      nf7::gui::NodeOutputSockets(node_->GetOutputs());
+      nf7::gui::NodeOutputSockets(meta_.outputs);
     }
   }
   ImNodes::EndNode();

file/node_ref.cc

@@ -77,11 +77,8 @@ class Ref final : public nf7::FileBase, public nf7::Node {
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    return mem_->inputs;
+    return {mem_->inputs, mem_->outputs};
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return mem_->outputs;
   }
 
   void UpdateNode(nf7::Node::Editor&) noexcept override;
@@ -116,12 +113,13 @@ class Ref final : public nf7::FileBase, public nf7::Node {
     bool mod = false;
     try {
       auto& n = target().interfaceOrThrow<nf7::Node>();
+      const auto meta = n.GetMeta();
 
-      const auto srci = n.GetInputs();
+      const auto& srci = meta.inputs;
       mod |= std::equal(dsti.begin(), dsti.end(), srci.begin(), srci.end());
       dsti = std::vector<std::string>{srci.begin(), srci.end()};
 
-      const auto srco = n.GetOutputs();
+      const auto& srco = meta.outputs;
       mod |= std::equal(dsto.begin(), dsto.end(), srco.begin(), srco.end());
       dsto = std::vector<std::string>{srco.begin(), srco.end()};
     } catch (nf7::Exception& e) {

file/sequencer_call.cc

@@ -180,7 +180,8 @@ try {
   }
 
   ssla_->Listen(*file_, ss);
-  for (const auto& name : node.GetInputs()) {
+  const auto inputs = node.GetMeta().inputs;
+  for (const auto& name : inputs) {
     if (auto v = ss->Receive(name)) {
       la_->Handle(name, *v, ssla_);
     }

file/sequencer_timeline.cc

@@ -90,13 +90,8 @@ class TL final : public nf7::FileBase, public nf7::DirItem, public nf7::Node {
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"exec"};
+    return {{"exec"}, {"result"}};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    static const std::vector<std::string> kOutputs = {"result"};
-    return kOutputs;
   }
 
   void PostHandle(const nf7::File::Event& ev) noexcept;

file/system_call.cc

@@ -51,12 +51,8 @@ class Call final : public nf7::File, public nf7::Node {
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"save", "exit", "abort", "panic"};
+    return {{"save", "exit", "abort", "panic"}, {}};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return {};
   }
 
   void UpdateNode(nf7::Node::Editor&) noexcept override;

file/system_event.cc

@@ -92,12 +92,8 @@ class Event final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"value"};
+    return {{"value"}, {}};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return {};
   }
 
   void PostUpdate() noexcept override;
@@ -121,12 +117,6 @@ class Event final : public nf7::FileBase,
   nf7::Node& GetHandler() const {
     return ResolveOrThrow(mem_->handler).interfaceOrThrow<nf7::Node>();
   }
-  std::span<const std::string> GetHandlerInputs() const noexcept
-  try {
-    return GetHandler().GetInputs();
-  } catch (nf7::Exception&) {
-    return {};
-  }
   std::shared_ptr<nf7::Node::Lambda> CreateLambdaIf() noexcept {
     try {
       if (!la_) {
@@ -180,9 +170,7 @@ std::shared_ptr<nf7::Node::Lambda> Event::CreateLambda(
 
 void Event::PostUpdate() noexcept {
   const auto& io = ImGui::GetIO();
-  const auto  in = GetHandlerInputs();
 
-  if (in.end() != std::find(in.begin(), in.end(), "key")) {
   for (size_t i = 0; i < ImGuiKey_KeysData_SIZE; ++i) {
     const auto& key   = io.KeysData[i];
     const char* event = nullptr;
@@ -197,7 +185,6 @@ void Event::PostUpdate() noexcept {
     }
   }
 }
-}
 void Event::UpdateMenu() noexcept {
   if (ImGui::MenuItem("drop handler's lambda")) {
     la_ = nullptr;

file/system_nfile.cc

@@ -143,14 +143,8 @@ class NFile final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-
+  nf7::Node::Meta GetMeta() const noexcept override {
-  std::span<const std::string> GetInputs() const noexcept override {
+    return {{"command"}, {"result"}};
-    static const std::vector<std::string> kInputs = {"command"};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    static const std::vector<std::string> kOutputs = {"result"};
-    return kOutputs;
   }
 
   void UpdateTooltip() noexcept override;

file/value_curve.cc

@@ -97,13 +97,8 @@ class Curve final : public nf7::FileBase,
   std::shared_ptr<nf7::Sequencer::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Context>&) noexcept override;
 
-  std::span<const std::string> GetInputs() const noexcept override {
+  nf7::Node::Meta GetMeta() const noexcept override {
-    static const std::vector<std::string> kInputs = {"x"};
+    return {{"x"}, {"y"}};
-    return kInputs;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    static const std::vector<std::string> kOutputs = {"y"};
-    return kOutputs;
   }
 
   void UpdateItem(nf7::Sequencer::Editor&) noexcept override;

file/value_plot.cc

@@ -134,12 +134,8 @@ class Plot final : public nf7::FileBase,
 
   std::shared_ptr<nf7::Node::Lambda> CreateLambda(
       const std::shared_ptr<nf7::Node::Lambda>&) noexcept override;
-
+  nf7::Node::Meta GetMeta() const noexcept override {
-  std::span<const std::string> GetInputs() const noexcept override {
+    return {inputs_, {}};
-    return inputs_;
-  }
-  std::span<const std::string> GetOutputs() const noexcept override {
-    return {};
   }
 
   void UpdateMenu() noexcept override;