Define common data structures with protobuf. (#5121)

python/setup.py

@@ -28,11 +28,10 @@ ray_files = [
     "ray/dashboard/res/main.css", "ray/dashboard/res/main.js"
 ]
 
-# These are the directories where automatically generated Python flatbuffer
+# These are the directories where automatically generated Python protobuf
 # bindings are created.
 generated_python_directories = [
-    "ray/core/generated", "ray/core/generated/ray",
-    "ray/core/generated/ray/protocol"
+    "ray/core/generated",
 ]
 
 optional_ray_files = []
@@ -88,7 +87,7 @@ class build_ext(_build_ext.build_ext):
 
         files_to_include = ray_files + pyarrow_files + modin_files
 
-        # Copy over the autogenerated flatbuffer Python bindings.
+        # Copy over the autogenerated protobuf Python bindings.
         for directory in generated_python_directories:
             for filename in os.listdir(directory):
                 if filename[-3:] == ".py":
@@ -148,7 +147,6 @@ requires = [
     # NOTE: Don't upgrade the version of six! Doing so causes installation
     # problems. See https://github.com/ray-project/ray/issues/4169.
     "six >= 1.0.0",
-    "flatbuffers",
     "faulthandler;python_version<'3.3'",
     "protobuf >= 3.8.0",
 ]