forked from facebook/fbthrift
-
Notifications
You must be signed in to change notification settings - Fork 0
/
legacy_reflection.h
173 lines (159 loc) · 5.41 KB
/
legacy_reflection.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/*
* Copyright 2016 Facebook, Inc.
*
* 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.
*/
#pragma once
#include <fatal/type/cat.h>
#include <thrift/lib/cpp2/fatal/reflection.h>
#include <thrift/lib/cpp2/fatal/container_traits.h>
#include <thrift/lib/thrift/gen-cpp2/reflection_types.h>
/**
* READ ME FIRST: this header backports static reflection metatypes to legacy
* reflection metadata for Thrift types.
*
* Please refer to the top of `thrift/lib/cpp2/fatal/reflection.h` on how to
* enable compile-time reflection for Thrift types. The present header relies on
* it for its functionality.
*
* TROUBLESHOOTING:
* - make sure you've followed the instructions on `reflection.h` to enable
* generation of compile-time reflection;
* - make sure you've included the metadata for your Thrift types, as specified
* in `reflection.h`.
*/
#include <thrift/lib/cpp2/fatal/internal/legacy_reflection-inl-pre.h>
namespace apache { namespace thrift {
using legacy_reflection_id_t = std::uint64_t;
using legacy_reflection_schema_t = reflection::Schema;
/***
* Provides access to the legacy reflection utilities for a Thrift type `T`.
*
* See the individual member methods for more information.
*/
template <typename T>
struct legacy_reflection {
/***
* Registers legacy metadata about Thrift type `T`, and all Thrift types
* transitively used by `T`, into `schema` using Thrift's static reflection
* support.
*
* Mimics the behavior of `T::_reflection_register` generated by Thrift 1.
*
* NOTE: look at the top of this file for instructions on how to enable
* reflection support.
*
* Usage example:
*
* // MyModule.thrift
* struct MyStruct {
* 1: string data,
* }
*
* // C++
* apache::thrift::reflection::Schema schema;
* apache::thrift::legacy_reflection<MyStruct>::register_into(schema);
* for (const auto& kvp : schema.names) {
* const auto& rname = kvp.first;
* const auto rid = kvp.second;
* const auto& datatype = schema.dataTypes[rid];
* LOG(INFO) << datatype.name;
* }
* // Writes two unordered log lines:
* // struct MyModule.MyStruct
* // string
*
* WARNING: This function uses a hash function implemented by OpenSSL; which
* is not thread-safe until OpenSSL is initialized.
*/
static void register_into(legacy_reflection_schema_t& schema);
/***
* Returns legacy metadata about Thrift type `T`, and all Thrift types
* transitively used by `T`, in a schema using Thrift's static reflection
* support.
*
* Mimics the behavior of `T::_reflection_register` generated by Thrift 1.
*
* NOTE: look at the top of this file for instructions on how to enable
* reflection support.
*
* Usage example:
*
* // MyModule.thrift
* struct MyStruct {
* 1: string data,
* }
*
* // C++
* auto schema = apache::thrift::legacy_reflection<MyStruct>::schema();
* for (const auto& kvp : schema.names) {
* const auto& rname = kvp.first;
* const auto rid = kvp.second;
* const auto& datatype = schema.dataTypes[rid];
* LOG(INFO) << datatype.name;
* }
* // Writes two unordered log lines:
* // struct MyModule.MyStruct
* // string
*
* WARNING: This function uses a hash function implemented by OpenSSL; which
* is not thread-safe until OpenSSL is initialized.
*/
static legacy_reflection_schema_t schema();
/***
* Returns the legacy reflection name of a Thrift type `T` using Thrift's
* static reflection support.
*
* Mimics the strings created by the behavior of `T::__reflection_register`
* generated by Thrift 1.
*
* NOTE: look at the top of this file for instructions on how to enable
* reflection support.
*
* Usage example:
*
* // MyModule.thrift
* struct MyStruct {}
*
* // C++
* LOG(INFO) << apache::thrift::legacy_reflection<MyStruct>::name();
* // Writes the log line:
* // struct MyModule.MyStruct
*/
static constexpr folly::StringPiece name();
/***
* Returns the legacy reflection id of a Thrift type `T` using Thrift's
* static reflection support.
*
* Mimics the behavior of `T::_reflection_id` generated by Thrift 1.
*
* NOTE: look at the top of this file for instructions on how to enable
* reflection support.
*
* Usage example:
*
* // MyModule.thrift
* struct MyStruct {}
*
* // C++
* LOG(INFO) << apache::thrift::legacy_reflection<MyStruct>::id();
* // Writes the log line:
* // <some constant 64-bit unsigned integer>
*
* WARNING: This function uses a hash function implemented by OpenSSL; which
* is not thread-safe until OpenSSL is initialized.
*/
static legacy_reflection_id_t id();
};
}}
#include <thrift/lib/cpp2/fatal/internal/legacy_reflection-inl-post.h>