Use a map to look up dispatchers for Dart FFI function names (flutter…

…#34771)
a-siva · Jul 20, 2022 · f353726 · f353726
1 parent 16fe58d
commit f353726
Showing 1 changed file with 31 additions and 14 deletions.
diff --git a/lib/ui/dart_ui.cc b/lib/ui/dart_ui.cc
@@ -4,6 +4,8 @@
 
 #include "flutter/lib/ui/dart_ui.h"
 
+#include <string_view>
+
 #include "flutter/common/settings.h"
 #include "flutter/fml/build_config.h"
 #include "flutter/lib/ui/compositing/scene.h"
@@ -279,26 +281,41 @@ typedef CanvasPath Path;
   V(SemanticsUpdateBuilder, updateNode, 36)            \
   V(SemanticsUpdate, dispose, 1)
 
-#define FFI_FUNCTION_MATCH(FUNCTION, ARGS)                                 \
-  if (strcmp(name, #FUNCTION) == 0 && args == ARGS) {                      \
-    return reinterpret_cast<void*>(                                        \
-        tonic::FfiDispatcher<void, decltype(&FUNCTION), &FUNCTION>::Call); \
-  }
+#define FFI_FUNCTION_INSERT(FUNCTION, ARGS)   \
+  function_dispatchers.insert(std::make_pair( \
+      std::string_view(#FUNCTION),            \
+      reinterpret_cast<void*>(                \
+          tonic::FfiDispatcher<void, decltype(&FUNCTION), &FUNCTION>::Call)));
 
-#define FFI_METHOD_MATCH(CLASS, METHOD, ARGS)                   \
-  if (strcmp(name, #CLASS "::" #METHOD) == 0 && args == ARGS) { \
-    return reinterpret_cast<void*>(                             \
-        tonic::FfiDispatcher<CLASS, decltype(&CLASS::METHOD),   \
-                             &CLASS::METHOD>::Call);            \
-  }
+#define FFI_METHOD_INSERT(CLASS, METHOD, ARGS)                                 \
+  function_dispatchers.insert(                                                 \
+      std::make_pair(std::string_view(#CLASS "::" #METHOD),                    \
+                     reinterpret_cast<void*>(                                  \
+                         tonic::FfiDispatcher<CLASS, decltype(&CLASS::METHOD), \
+                                              &CLASS::METHOD>::Call)));
+
+namespace {
+
+std::unordered_map<std::string_view, void*> function_dispatchers;
 
 void* ResolveFfiNativeFunction(const char* name, uintptr_t args) {
-  FFI_FUNCTION_LIST(FFI_FUNCTION_MATCH)
-  FFI_METHOD_LIST(FFI_METHOD_MATCH)
-  return nullptr;
+  auto it = function_dispatchers.find(name);
+  return (it != function_dispatchers.end()) ? it->second : nullptr;
 }
 
+void InitDispatcherMap() {
+  if (!function_dispatchers.empty()) {
+    return;
+  }
+  FFI_FUNCTION_LIST(FFI_FUNCTION_INSERT)
+  FFI_METHOD_LIST(FFI_METHOD_INSERT)
+}
+
+}  // anonymous namespace
+
 void DartUI::InitForIsolate(const Settings& settings) {
+  InitDispatcherMap();
+
   auto dart_ui = Dart_LookupLibrary(ToDart("dart:ui"));
   if (Dart_IsError(dart_ui)) {
     Dart_PropagateError(dart_ui);