1 // Copyright 2016 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_SERIALIZATION_FORWARD_H_
6 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_SERIALIZATION_FORWARD_H_
7
8 #include "base/optional.h"
9 #include "mojo/public/cpp/bindings/array_traits.h"
10 #include "mojo/public/cpp/bindings/enum_traits.h"
11 #include "mojo/public/cpp/bindings/lib/template_util.h"
12 #include "mojo/public/cpp/bindings/map_traits.h"
13 #include "mojo/public/cpp/bindings/string_traits.h"
14 #include "mojo/public/cpp/bindings/struct_traits.h"
15
16 // This file is included by serialization implementation files to avoid circular
17 // includes.
18 // Users of the serialization funtions should include serialization.h (and also
19 // wtf_serialization.h if necessary).
20
21 namespace mojo {
22 namespace internal {
23
24 template <typename MojomType, typename MaybeConstUserType>
25 struct Serializer;
26
27 template <typename T>
28 struct IsOptionalWrapper {
29 static const bool value = IsSpecializationOf<
30 base::Optional,
31 typename std::remove_const<
32 typename std::remove_reference<T>::type>::type>::value;
33 };
34
35 // PrepareToSerialize() must be matched by a Serialize() for the same input
36 // later. Moreover, within the same SerializationContext if PrepareToSerialize()
37 // is called for |input_1|, ..., |input_n|, Serialize() must be called for
38 // those objects in the exact same order.
39 template <typename MojomType,
40 typename InputUserType,
41 typename... Args,
42 typename std::enable_if<
43 !IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
PrepareToSerialize(InputUserType && input,Args &&...args)44 size_t PrepareToSerialize(InputUserType&& input, Args&&... args) {
45 return Serializer<MojomType,
46 typename std::remove_reference<InputUserType>::type>::
47 PrepareToSerialize(std::forward<InputUserType>(input),
48 std::forward<Args>(args)...);
49 }
50
51 template <typename MojomType,
52 typename InputUserType,
53 typename... Args,
54 typename std::enable_if<
55 !IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
Serialize(InputUserType && input,Args &&...args)56 void Serialize(InputUserType&& input, Args&&... args) {
57 Serializer<MojomType, typename std::remove_reference<InputUserType>::type>::
58 Serialize(std::forward<InputUserType>(input),
59 std::forward<Args>(args)...);
60 }
61
62 template <typename MojomType,
63 typename DataType,
64 typename InputUserType,
65 typename... Args,
66 typename std::enable_if<
67 !IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
Deserialize(DataType && input,InputUserType * output,Args &&...args)68 bool Deserialize(DataType&& input, InputUserType* output, Args&&... args) {
69 return Serializer<MojomType, InputUserType>::Deserialize(
70 std::forward<DataType>(input), output, std::forward<Args>(args)...);
71 }
72
73 // Specialization that unwraps base::Optional<>.
74 template <typename MojomType,
75 typename InputUserType,
76 typename... Args,
77 typename std::enable_if<
78 IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
PrepareToSerialize(InputUserType && input,Args &&...args)79 size_t PrepareToSerialize(InputUserType&& input, Args&&... args) {
80 if (!input)
81 return 0;
82 return PrepareToSerialize<MojomType>(*input, std::forward<Args>(args)...);
83 }
84
85 template <typename MojomType,
86 typename InputUserType,
87 typename DataType,
88 typename... Args,
89 typename std::enable_if<
90 IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
Serialize(InputUserType && input,Buffer * buffer,DataType ** output,Args &&...args)91 void Serialize(InputUserType&& input,
92 Buffer* buffer,
93 DataType** output,
94 Args&&... args) {
95 if (!input) {
96 *output = nullptr;
97 return;
98 }
99 Serialize<MojomType>(*input, buffer, output, std::forward<Args>(args)...);
100 }
101
102 template <typename MojomType,
103 typename DataType,
104 typename InputUserType,
105 typename... Args,
106 typename std::enable_if<
107 IsOptionalWrapper<InputUserType>::value>::type* = nullptr>
Deserialize(DataType && input,InputUserType * output,Args &&...args)108 bool Deserialize(DataType&& input, InputUserType* output, Args&&... args) {
109 if (!input) {
110 *output = base::nullopt;
111 return true;
112 }
113 if (!*output)
114 output->emplace();
115 return Deserialize<MojomType>(std::forward<DataType>(input), &output->value(),
116 std::forward<Args>(args)...);
117 }
118
119 } // namespace internal
120 } // namespace mojo
121
122 #endif // MOJO_PUBLIC_CPP_BINDINGS_LIB_SERIALIZATION_FORWARD_H_
123