refactor Enum code generation

Summary:
Changed the way how enums generated in thrift-py3:

1. Use C++ map to store name to unique Enum Python instances cache
2. Dynamically find instances from cache (or create one and add to cache) instead of populating all instances at module load time
3. use `__getattr__` and `__getitem__` instead of code-gen all the getters

Reviewed By: asp2insp

Differential Revision: D23182622

fbshipit-source-id: 75baef997ee2d604b4ef7606f282cfc3306208ac

thrift/compiler/generate/t_mstch_py3_generator.cc

@@ -778,7 +778,7 @@ class mstch_py3_field : public mstch_field {
             {"field:isset?", &mstch_py3_field::isSet},
             {"field:cppName", &mstch_py3_field::cppName},
             {"field:hasModifiedName?", &mstch_py3_field::hasModifiedName},
-            {"field:enumSafeName", &mstch_py3_field::enumSafeName},
+            {"field:hasPyName?", &mstch_py3_field::hasPyName},
         });
   }
 
@@ -837,11 +837,8 @@ class mstch_py3_field : public mstch_field {
     return pyName_ != cppName_;
   }
 
-  mstch::node enumSafeName() {
-    if (pyName_ == "name" || pyName_ == "value") {
-      return pyName_ + "_";
-    }
-    return pyName_;
+  mstch::node hasPyName() {
+    return pyName_ != field_->get_name();
   }
 
   bool has_default_value() {
@@ -1010,7 +1007,7 @@ class mstch_py3_enum_value : public mstch_enum_value {
         {
             {"enumValue:py_name", &mstch_py3_enum_value::pyName},
             {"enumValue:cppName", &mstch_py3_enum_value::cppName},
-            {"enumValue:enumSafeName", &mstch_py3_enum_value::enumSafeName},
+            {"enumValue:hasPyName?", &mstch_py3_enum_value::hasPyName},
         });
   }
 
@@ -1022,12 +1019,8 @@ class mstch_py3_enum_value : public mstch_enum_value {
     return get_cppname<t_enum_value>(*enm_value_);
   }
 
-  mstch::node enumSafeName() {
-    auto pyName = py3::get_py3_name(*enm_value_);
-    if (pyName == "name" || pyName == "value") {
-      return pyName + "_";
-    }
-    return pyName;
+  mstch::node hasPyName() {
+    return py3::get_py3_name(*enm_value_) != enm_value_->get_name();
   }
 };
 
@@ -1456,13 +1449,16 @@ void t_mstch_py3_generator::generate_module(ModuleType moduleType) {
   if (moduleType != ModuleType::REFLECTIONS) {
     exts.push_back(".pyi");
   }
+  if (moduleType == ModuleType::TYPES) {
+    exts.push_back(".h");
+  }
   for (auto ext : exts) {
     render_to_file(
         nodePtr, module + ext, generateRootPath_ / name / (module + ext));
   }
+  auto cpp_path = boost::filesystem::path{name};
   if (moduleType == ModuleType::CLIENTS || moduleType == ModuleType::SERVICES) {
     auto basename = module + "_wrapper";
-    auto cpp_path = boost::filesystem::path{name};
     for (auto ext : {".h", ".cpp"}) {
       render_to_file(nodePtr, basename + ext, cpp_path / (basename + ext));
     }
@@ -1474,6 +1470,7 @@ void t_mstch_py3_generator::generate_module(ModuleType moduleType) {
   }
 
   if (moduleType == ModuleType::TYPES) {
+    render_to_file(nodePtr, "types.h", cpp_path / "types.h");
     programNodePtr->setTypeContext(false);
     for (auto ext : {".pxd", ".pyx"}) {
       const auto filename = std::string{"types_reflection"} + ext;

thrift/compiler/generate/templates/py3/CythonFieldValueForAssignment.mustache

@@ -50,9 +50,7 @@ on a struct.
   }}{{#type:string?}}.encode('utf-8'))){{/type:string?}}{{!
   }}{{#type:binary?}})){{/type:binary?}}{{!
 }}{{/type:base?}}{{!
-}}{{#type:enum?}}{{!
-    }}{{> types/CythonPythonType}}_to_cpp({{field:py_name}}){{!
-}}{{/type:enum?}}{{!
+}}{{#type:enum?}}<{{> types/CythonCppType}}><int>{{field:py_name}}{{/type:enum?}}{{!
 }}{{#type:struct?}}{{!
     }}deref((<{{> types/CythonPythonType }}?> {{field:py_name}})._cpp_obj){{!
 }}{{/type:struct?}}{{!

thrift/compiler/generate/templates/py3/CythonPythonToCppArg.mustache

@@ -44,5 +44,5 @@ This template assumes that the Python object is in a variable named <field>.
 }}{{#type:container?}}{{!
   }}deref((<{{> types/CythonPythonType}}>{{field:py_name}})._cpp_obj){{!
 }}{{/type:container?}}{{!
-}}{{#type:enum}}{{> types/CythonPythonType}}_to_cpp({{field:py_name}}){{/type:enum}}{{!
+}}{{#type:enum?}}<{{> types/CythonCppType}}><int>{{field:py_name}}{{/type:enum?}}{{!
 }}{{/type:hasCustomTypeBehavior?}}

thrift/compiler/generate/templates/py3/CythonPythonToCppItem.mustache

@@ -50,5 +50,5 @@ key, include the parallel CythonPythonToCppKey file instead.
 }}{{#type:container?}}{{!
   }}deref((<{{> types/CythonPythonType}}>item)._cpp_obj){{!
 }}{{/type:container?}}{{!
-}}{{#type:enum}}{{> types/CythonPythonType}}_to_cpp(item){{/type:enum}}{{!
+}}{{#type:enum?}}<{{> types/CythonCppType}}><int>item{{/type:enum?}}{{!
 }}{{/type:hasCustomTypeBehavior?}}

thrift/compiler/generate/templates/py3/CythonPythonToCppKey.mustache

@@ -40,4 +40,4 @@ keys (conventionally used for sets, lists, and map values).
 }}{{#type:container?}}{{!
   }}deref((<{{> types/CythonPythonType}}>key)._cpp_obj){{!
 }}{{/type:container?}}{{!
-}}{{#type:enum}}{{> types/CythonPythonType}}_to_cpp(key){{/type:enum}}
+}}{{#type:enum?}}<{{> types/CythonCppType}}><int>key{{/type:enum?}}

thrift/compiler/generate/templates/py3/CythonUnionAssignField.mustache

@@ -68,7 +68,7 @@ on a union.
 }}{{/type:binary?}}{{!
 }}{{#type:enum?}}{{!
   }}deref(c_inst).set_{{field:py_name}}({{!
-    }}{{> types/CythonPythonType}}_to_cpp({{field:py_name}})){{!
+    }}<{{> types/CythonCppType}}><int>{{field:py_name}}){{!
 }}{{/type:enum?}}{{!
 }}{{#type:struct?}}{{!
   }}deref(c_inst).set_{{field:py_name}}({{!

thrift/compiler/generate/templates/py3/services/CythonReturnValue.mustache

@@ -73,5 +73,5 @@ to the client.
   }}{{^program:stack_arguments?}}){{/program:stack_arguments?}}{{!
 }}{{/type:container?}}{{!
 }}{{#type:void?}}c_unit{{/type:void?}}{{!
-}}{{#type:enum}}{{> types/CythonPythonType}}_to_cpp(result){{/type:enum}}{{!
+}}{{#type:enum?}}<{{> types/CythonCppType}}><int>result{{/type:enum?}}{{!
 }}{{/type:hasCustomTypeBehavior?}}

thrift/compiler/generate/templates/py3/types.h.mustache

@@ -0,0 +1,60 @@
+{{!
+
+  Copyright (c) Facebook, Inc. and its affiliates.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+}}{{!
+
+C++ header to store py3 specific Enum and Union type enum data
+
+}}
+{{> common/AutoGeneratedC}}
+
+#pragma once
+
+#include <thrift/lib/py3/enums.h>
+#include "{{program:includePrefix}}gen-cpp2/{{program:name}}_types.h"
+{{#program:enums}}
+
+template<>
+const std::vector<std::pair<std::string_view, std::string_view>>& ::thrift::py3::PyEnumTraits<
+    {{#program:cppNamespaces}}::{{value}}{{/program:cppNamespaces}}::{{enum:name}}>::namesmap() {
+  static const folly::Indestructible<NamesMap> pairs {
+    {
+      {{#enum:values}}{{#enumValue:hasPyName?}}
+      {"{{enumValue:py_name}}", "{{enumValue:name}}"},
+      {{/enumValue:hasPyName?}}{{/enum:values}}
+    }
+  };
+  return *pairs;
+}
+
+{{/program:enums}}
+{{#program:structs}}
+{{#struct:union?}}
+
+template<>
+const std::vector<std::pair<std::string_view, std::string_view>>& ::thrift::py3::PyEnumTraits<
+    {{#program:cppNamespaces}}::{{value}}{{/program:cppNamespaces}}::{{struct:name}}::Type>::namesmap() {
+  static const folly::Indestructible<NamesMap> pairs {
+    {
+      {{#struct:fields}}{{#field:hasPyName?}}
+      {"{{field:py_name}}", "{{field:name}}"},
+      {{/field:hasPyName?}}{{/struct:fields}}
+    }
+  };
+  return *pairs;
+}
+{{/struct:union?}}
+{{/program:structs}}

thrift/compiler/generate/templates/py3/types.pxd.mustache

@@ -58,6 +58,8 @@ from thrift.py3.common cimport RpcOptions as __RpcOptions
 {{#program:includeNamespaces}}
 cimport {{#includeNamespace}}{{value}}.{{/includeNamespace}}types as _{{#includeNamespace}}{{value}}_{{/includeNamespace}}types
 {{/program:includeNamespaces}}
+cdef extern from "{{program:includePrefix}}gen-py3/{{program:name}}/types.h":
+  pass
 
 {{#program:cppIncludes}}
 cdef extern from "{{.}}":
@@ -76,11 +78,8 @@ cdef extern from "{{program:includePrefix}}gen-cpp2/{{program:name}}_types.h"{{!
 }} namespace "{{#program:cppNamespaces}}::{{value}}{{/program:cppNamespaces}}":
 {{/first?}}
     cdef cppclass c{{enum:name}} "::{{#program:cppNamespaces}}{{value}}::{{/program:cppNamespaces}}{{enum:name}}":
-        bint operator==(c{{enum:name}}&)
-        bint operator!=(c{{enum:name}}&)
-    {{#enum:values}}
-    c{{enum:name}} {{enum:name}}__{{enumValue:py_name}} "::{{#program:cppNamespaces}}{{value}}::{{/program:cppNamespaces}}{{enum:name}}::{{enumValue:cppName}}"
-    {{/enum:values}}
+        pass
+
 {{/program:enums}}
 
 

thrift/compiler/generate/templates/py3/types.pyi.mustache

@@ -46,7 +46,7 @@ __property__ = property
 {{#program:enums}}
 class {{enum:name}}(thrift.py3.types.{{^enum:flags?}}Enum{{/enum:flags?}}{{#enum:flags?}}Flag{{/enum:flags?}}):
     {{#enum:values}}
-    {{enumValue:enumSafeName}}: {{enum:name}} = ...
+    {{enumValue:py_name}}: {{enum:name}} = ...
     {{/enum:values}}
     {{^enum:values}}
     pass
@@ -100,7 +100,7 @@ class {{struct:name}}({{> types/PythonStructClass}}, _typing.Hashable{{^struct:u
     class Type(thrift.py3.types.Enum):
         EMPTY: {{struct:name}}.Type = ...
     {{#struct:fields}}
-        {{field:enumSafeName}}: {{struct:name}}.Type = ...
+        {{field:py_name}}: {{struct:name}}.Type = ...
     {{/struct:fields}}
 
     @staticmethod

thrift/compiler/generate/templates/py3/types.pyx.mustache

@@ -40,6 +40,7 @@ from libcpp.memory cimport shared_ptr, make_shared, unique_ptr, make_unique
 from libcpp.string cimport string
 from libcpp cimport bool as cbool
 from libcpp.iterator cimport inserter as cinserter
+from libcpp.utility cimport move as cmove
 from cpython cimport bool as pbool
 from cython.operator cimport dereference as deref, preincrement as inc, address as ptr_address
 import thrift.py3.types
@@ -51,6 +52,10 @@ from thrift.py3.types cimport (
     constant_shared_ptr,
     default_inst,
     NOTSET as __NOTSET,
+    EnumData as __EnumData,
+    EnumFlagsData as __EnumFlagsData,
+    UnionTypeEnumData as __UnionTypeEnumData,
+    createEnumDataForUnionType as __createEnumDataForUnionType,
 )
 cimport thrift.py3.std_libcpp as std_libcpp
 cimport thrift.py3.serializer as serializer
@@ -61,7 +66,6 @@ from folly.optional cimport cOptional
 import sys
 import itertools
 from collections.abc import Sequence, Set, Mapping, Iterable
-import warnings
 import weakref as __weakref
 import builtins as _builtins
 {{#program:has_stream?}}