Adding watch option using dmon (#1308)

This add support for an "--watch" cli option where the current file is reloaded automatically if changed on disk.
It relies on https://github.com/septag/dmon for detecting the changes.

In order to support this properly, F3DStarter is reworked with a proper event loops that currently supports:
 - Reloading the current file
 - Rendering

This also adds a test for it on linux/apple/windows

.cppcheck.supp

@@ -6,6 +6,7 @@ unknownMacro
 // external libraries
 *:external/nlohmann_json/nlohmann/json.hpp
 *:external/cxxopts/cxxopts.hpp
+*:external/dmon/dmon.h
 
 // specific checks
 knownConditionTrueFalse:library/testing/TestSDKImage.cxx

.github/actions/coverage-ci/action.yml

@@ -102,6 +102,7 @@ runs:
         lcov --remove coverage.info "*/dependencies/*" -o coverage.info
         lcov --remove coverage.info "*/cxxopts.hpp" -o coverage.info
         lcov --remove coverage.info "*/json.hpp" -o coverage.info
+        lcov --remove coverage.info "*/dmon.h" -o coverage.info
         lcov --remove coverage.info "*Test*" -o coverage.info
 
     - name: Upload coverage to Codecov

.tsan.supp

@@ -10,3 +10,7 @@ race:libvtkCommonDataModel
 
 # OpenEXR
 race:libOpenEXR
+
+# dmon
+# https://github.com/septag/dmon/issues/33
+race:dmon.h

CMakeLists.txt

@@ -60,13 +60,17 @@ option(F3D_MODULE_EXR "OpenEXR images module" OFF)
 # Use externals
 option(F3D_USE_EXTERNAL_CXXOPTS "Use external cxxopts dependency" OFF)
 option(F3D_USE_EXTERNAL_NLOHMANN_JSON "Use external nlohmann_json dependency" OFF)
+option(F3D_USE_EXTERNAL_DMON "Use external dmon dependency" OFF)
 
 if (F3D_USE_EXTERNAL_CXXOPTS)
   find_package(cxxopts REQUIRED)
 endif ()
 if (F3D_USE_EXTERNAL_NLOHMANN_JSON)
   find_package(nlohmann_json REQUIRED)
 endif ()
+if (F3D_USE_EXTERNAL_DMON)
+  find_package(dmon REQUIRED)
+endif ()
 
 # VTK dependency
 # Optional components should list VTK modules

application/CMakeLists.txt

@@ -57,6 +57,7 @@ elseif (MSVC)
 endif ()
 
 target_include_directories(f3d PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>)
+
 if (F3D_USE_EXTERNAL_CXXOPTS)
   target_link_libraries(f3d PRIVATE cxxopts::cxxopts)
 else ()
@@ -69,6 +70,12 @@ else ()
   target_include_directories(f3d PUBLIC $<BUILD_INTERFACE:${F3D_SOURCE_DIR}/external/nlohmann_json>)
 endif ()
 
+if (F3D_USE_EXTERNAL_DMON)
+  target_link_libraries(f3d PRIVATE dmon::dmon)
+else ()
+  target_include_directories(f3d PUBLIC $<BUILD_INTERFACE:${F3D_SOURCE_DIR}/external/dmon>)
+endif ()
+
 set(f3d_compile_options_private "")
 set(f3d_compile_options_public "")
 set(f3d_link_options_public "")

application/F3DOptionsParser.cxx

@@ -311,6 +311,7 @@ void ConfigurationOptions::GetOptions(F3DAppOptions& appOptions, f3d::options& o
     this->DeclareOption(grp0, "dry-run", "", "Do not read the configuration file", appOptions.DryRun,  HasDefault::YES, MayHaveConfig::NO );
     this->DeclareOption(grp0, "no-render", "", "Do not render anything and quit right after loading the first file, use with --verbose to recover information about a file.", appOptions.NoRender,  HasDefault::YES, MayHaveConfig::YES );
     this->DeclareOption(grp0, "max-size", "", "Maximum size in Mib of a file to load, negative value means unlimited", appOptions.MaxSize,  HasDefault::YES, MayHaveConfig::YES, "<size in Mib>");
+    this->DeclareOption(grp0, "watch", "", "Watch current file and automatically reload it whenever it is modified on disk", appOptions.Watch,  HasDefault::YES, MayHaveConfig::YES );
     this->DeclareOption(grp0, "load-plugins", "", "List of plugins to load separated with a comma", appOptions.Plugins, LocalHasDefaultNo, MayHaveConfig::YES, "<paths or names>");
     this->DeclareOption(grp0, "scan-plugins", "", "Scan some directories for plugins (result can be incomplete)");
 

application/F3DOptionsParser.h

@@ -29,6 +29,7 @@ struct F3DAppOptions
   std::string InteractionTestPlayFile = "";
   bool NoBackground = false;
   bool NoRender = false;
+  bool Watch = false;
   double RefThreshold = 50;
   double MaxSize = -1.0;
 

application/F3DStarter.cxx

@@ -6,16 +6,30 @@
 #include "F3DOptionsParser.h"
 #include "F3DSystemTools.h"
 
+#define DMON_IMPL
+#ifdef WIN32
+#pragma warning(push)
+#pragma warning(disable : 4505)
+#include "dmon.h"
+// dmon includes Windows.h which defines 'ERROR' and conflicts with log.h
+#undef ERROR
+#pragma warning(pop)
+#else
+#include "dmon.h"
+#endif
+
 #include "engine.h"
 #include "interactor.h"
 #include "log.h"
 #include "options.h"
 #include "window.h"
 
 #include <algorithm>
+#include <atomic>
 #include <cassert>
 #include <filesystem>
 #include <iostream>
+#include <mutex>
 #include <set>
 
 namespace fs = std::filesystem;
@@ -133,15 +147,35 @@ class F3DStarter::F3DInternals
     }
   }
 
+  static void dmonFolderChanged(
+    dmon_watch_id, dmon_action, const char*, const char* filename, const char*, void* userData)
+  {
+    F3DStarter* self = reinterpret_cast<F3DStarter*>(userData);
+    const std::lock_guard<std::mutex> lock(self->Internals->FilesListMutex);
+    fs::path filePath = self->Internals->FilesList[self->Internals->CurrentFileIndex];
+    if (filePath.filename().string() == std::string(filename))
+    {
+      self->Internals->ReloadFileRequested = true;
+    }
+  }
+
   F3DOptionsParser Parser;
   F3DAppOptions AppOptions;
   f3d::options DynamicOptions;
   f3d::options FileOptions;
   std::unique_ptr<f3d::engine> Engine;
   std::vector<fs::path> FilesList;
-  int CurrentFileIndex = -1;
+  dmon_watch_id FolderWatchId;
   bool LoadedFile = false;
   bool UpdateWithCommandLineParsing = true;
+
+  // dmon used atomic and mutex
+  std::atomic<int> CurrentFileIndex = -1;
+  std::mutex FilesListMutex;
+
+  // Event loop atomics
+  std::atomic<bool> RenderRequested = false;
+  std::atomic<bool> ReloadFileRequested = false;
 };
 
 //----------------------------------------------------------------------------
@@ -151,10 +185,17 @@ F3DStarter::F3DStarter()
   // Set option outside of command line and config file
   this->Internals->DynamicOptions.set(
     "ui.dropzone-info", "Drop a file or HDRI to load it\nPress H to show cheatsheet");
+
+  // Initialize dmon
+  dmon_init();
 }
 
 //----------------------------------------------------------------------------
-F3DStarter::~F3DStarter() = default;
+F3DStarter::~F3DStarter()
+{
+  // deinit dmon
+  dmon_deinit();
+}
 
 //----------------------------------------------------------------------------
 int F3DStarter::Start(int argc, char** argv)
@@ -219,41 +260,17 @@ int F3DStarter::Start(int argc, char** argv)
     interactor.setKeyPressCallBack(
       [this](int, const std::string& keySym) -> bool
       {
-        const auto loadFile = [this](int index, bool restoreCamera = false) -> bool
-        {
-          this->Internals->Engine->getInteractor().stopAnimation();
-
-          f3d::log::debug("========== Loading 3D file ==========");
-
-          if (restoreCamera)
-          {
-            f3d::camera& cam = this->Internals->Engine->getWindow().getCamera();
-            const auto camState = cam.getState();
-            this->LoadFile(index, true);
-            cam.setState(camState);
-          }
-          else
-          {
-            this->LoadFile(index, true);
-          }
-
-          f3d::log::debug("========== Rendering ==========");
-
-          this->Render();
-          return true;
-        };
-
         if (keySym == "Left")
         {
-          return loadFile(-1);
+          return this->LoadRelativeFile(-1);
         }
         if (keySym == "Right")
         {
-          return loadFile(+1);
+          return this->LoadRelativeFile(+1);
         }
         if (keySym == "Up")
         {
-          return loadFile(0, true);
+          return this->LoadRelativeFile(0, true);
         }
         if (keySym == "Down")
         {
@@ -264,7 +281,7 @@ int F3DStarter::Start(int argc, char** argv)
               this->Internals->FilesList[static_cast<size_t>(this->Internals->CurrentFileIndex)]
                 .parent_path(),
               true);
-            return loadFile(0);
+            return this->LoadRelativeFile(0);
           }
           return true;
         }
@@ -299,7 +316,7 @@ int F3DStarter::Start(int argc, char** argv)
         {
           this->LoadFile(index);
         }
-        this->Render();
+        this->RequestRender();
         return true;
       });
     window
@@ -337,7 +354,6 @@ int F3DStarter::Start(int argc, char** argv)
 
   if (!this->Internals->AppOptions.NoRender)
   {
-    f3d::log::debug("========== Rendering ==========");
     f3d::window& window = this->Internals->Engine->getWindow();
     f3d::interactor& interactor = this->Internals->Engine->getInteractor();
 
@@ -460,7 +476,9 @@ int F3DStarter::Start(int argc, char** argv)
       f3d::log::error("This is a headless build of F3D, interactive rendering is not supported");
       return EXIT_FAILURE;
 #else
-      this->Render();
+      // Create the event loop repeating timer
+      interactor.createTimerCallBack(30, [this]() { this->EventLoop(); });
+      this->RequestRender();
       interactor.start();
 #endif
     }
@@ -472,6 +490,7 @@ int F3DStarter::Start(int argc, char** argv)
 //----------------------------------------------------------------------------
 void F3DStarter::LoadFile(int index, bool relativeIndex)
 {
+  f3d::log::debug("========== Loading 3D file ==========");
   // When loading a file, store any changed options
   // into the dynamic options and use these dynamic option as the default
   // for loading the file while still applying file specific options on top of it
@@ -621,7 +640,20 @@ void F3DStarter::LoadFile(int index, bool relativeIndex)
     }
   }
 
-  if (!this->Internals->LoadedFile)
+  if (this->Internals->LoadedFile)
+  {
+    if (this->Internals->AppOptions.Watch)
+    {
+      // Always unwatch and watch current folder, even on reload
+      if (this->Internals->FolderWatchId.id > 0)
+      {
+        dmon_unwatch(this->Internals->FolderWatchId);
+      }
+      this->Internals->FolderWatchId = dmon_watch(
+        filePath.parent_path().string().c_str(), &F3DInternals::dmonFolderChanged, 0, this);
+    }
+  }
+  else
   {
     // No file loaded, remove any previously loaded file
     loader.loadGeometry("", true);
@@ -631,9 +663,17 @@ void F3DStarter::LoadFile(int index, bool relativeIndex)
   this->Internals->Engine->getOptions().set("ui.filename-info", filenameInfo);
 }
 
+//----------------------------------------------------------------------------
+void F3DStarter::RequestRender()
+{
+  // Render will be called by the next event loop
+  this->Internals->RenderRequested = true;
+}
+
 //----------------------------------------------------------------------------
 void F3DStarter::Render()
 {
+  f3d::log::debug("========== Rendering ==========");
   this->Internals->Engine->getWindow().render();
   f3d::log::debug("Render done");
 }
@@ -671,6 +711,8 @@ int F3DStarter::AddFile(const fs::path& path, bool quiet)
 
     if (it == this->Internals->FilesList.end())
     {
+      // In the main thread, we only need to guard writing
+      const std::lock_guard<std::mutex> lock(this->Internals->FilesListMutex);
       this->Internals->FilesList.push_back(tmpPath);
       return static_cast<int>(this->Internals->FilesList.size()) - 1;
     }
@@ -684,3 +726,40 @@ int F3DStarter::AddFile(const fs::path& path, bool quiet)
     }
   }
 }
+
+//----------------------------------------------------------------------------
+bool F3DStarter::LoadRelativeFile(int index, bool restoreCamera)
+{
+  this->Internals->Engine->getInteractor().stopAnimation();
+
+  if (restoreCamera)
+  {
+    f3d::camera& cam = this->Internals->Engine->getWindow().getCamera();
+    const auto camState = cam.getState();
+    this->LoadFile(index, true);
+    cam.setState(camState);
+  }
+  else
+  {
+    this->LoadFile(index, true);
+  }
+
+  this->RequestRender();
+
+  return true;
+}
+
+//----------------------------------------------------------------------------
+void F3DStarter::EventLoop()
+{
+  if (this->Internals->ReloadFileRequested)
+  {
+    this->LoadRelativeFile(0, true);
+    this->Internals->ReloadFileRequested = false;
+  }
+  if (this->Internals->RenderRequested)
+  {
+    this->Render();
+    this->Internals->RenderRequested = false;
+  }
+}

application/F3DStarter.h

@@ -34,7 +34,12 @@ class F3DStarter
   void LoadFile(int index = 0, bool relativeIndex = false);
 
   /**
-   * Trigger a render
+   * Trigger a render on the next event loop
+   */
+  void RequestRender();
+
+  /**
+   * Trigger a render immediately (must be called by the main thread)
    */
   void Render();
 
@@ -47,6 +52,19 @@ class F3DStarter
 private:
   class F3DInternals;
   std::unique_ptr<F3DInternals> Internals;
+
+  /**
+   * Internal method triggered when interacting with the application
+   * that load a file using relative index and handle camera restore
+   */
+  bool LoadRelativeFile(int relativeIndex = 0, bool restoreCamera = false);
+
+  /**
+   * Internal event loop that is triggered repeatedly to handle specific events:
+   * - Render
+   * - ReloadFile
+   */
+  void EventLoop();
 };
 
 #endif