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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
#ifndef RFL_CAPNPROTO_READER_HPP_
#define RFL_CAPNPROTO_READER_HPP_
#include <capnp/dynamic.h>
#include <cstddef>
#include <exception>
#include <string>
#include <string_view>
#include <type_traits>
#include <vector>
#include "../Bytestring.hpp"
#include "../Result.hpp"
#include "../always_false.hpp"
#include "../internal/is_literal.hpp"
#include "../internal/ptr_cast.hpp"
namespace rfl::capnproto {
class Reader {
public:
struct CapNProtoInputArray {
capnp::DynamicList::Reader val_;
};
struct CapNProtoInputMap {
capnp::DynamicStruct::Reader val_;
};
struct CapNProtoInputObject {
capnp::DynamicStruct::Reader val_;
};
struct CapNProtoInputUnion {
capnp::DynamicStruct::Reader val_;
};
struct CapNProtoInputVar {
capnp::DynamicValue::Reader val_;
};
using InputArrayType = CapNProtoInputArray;
using InputObjectType = CapNProtoInputObject;
using InputMapType = CapNProtoInputMap;
using InputUnionType = CapNProtoInputUnion;
using InputVarType = CapNProtoInputVar;
template <class T>
static constexpr bool has_custom_constructor =
(requires(InputVarType var) { T::from_capnproto_obj(var); });
bool is_empty(const InputVarType& _var) const noexcept {
return _var.val_.getType() == capnp::DynamicValue::VOID;
}
template <class T>
rfl::Result<T> to_basic_type(const InputVarType& _var) const noexcept {
const auto type = _var.val_.getType();
if constexpr (std::is_same<std::remove_cvref_t<T>, std::string>()) {
if (type != capnp::DynamicValue::TEXT) {
return error("Could not cast to string.");
}
return std::string(_var.val_.as<capnp::Text>().cStr());
} else if constexpr (std::is_same<std::remove_cvref_t<T>,
rfl::Bytestring>()) {
if (type != capnp::DynamicValue::DATA) {
return error("Could not cast to bytestring.");
}
const auto data = _var.val_.as<capnp::Data>();
const auto begin = internal::ptr_cast<const std::byte*>(data.begin());
return rfl::Bytestring(begin, begin + data.size());
} else if constexpr (std::is_same<std::remove_cvref_t<T>, bool>()) {
if (type != capnp::DynamicValue::BOOL) {
return error("Could not cast to boolean.");
}
return _var.val_.as<bool>();
} else if constexpr (std::is_floating_point<std::remove_cvref_t<T>>()) {
if (type != capnp::DynamicValue::FLOAT) {
return error("Could not cast to float.");
}
return static_cast<T>(_var.val_.as<double>());
} else if constexpr (std::is_integral<std::remove_cvref_t<T>>()) {
switch (type) {
case capnp::DynamicValue::INT:
return static_cast<T>(_var.val_.as<int64_t>());
case capnp::DynamicValue::UINT:
return static_cast<T>(_var.val_.as<uint64_t>());
default:
return error("Could not cast to an integer.");
}
} else if constexpr (internal::is_literal_v<T>) {
if (type != capnp::DynamicValue::ENUM) {
return error("Could not cast to an enum.");
}
return T::from_value(_var.val_.as<capnp::DynamicEnum>().getRaw());
} else {
static_assert(rfl::always_false_v<T>, "Unsupported type.");
}
}
rfl::Result<InputArrayType> to_array(
const InputVarType& _var) const noexcept {
if (_var.val_.getType() != capnp::DynamicValue::LIST) {
return error("Could not cast to a list.");
}
return InputArrayType{_var.val_.as<capnp::DynamicList>()};
}
rfl::Result<InputObjectType> to_object(
const InputVarType& _var) const noexcept {
if (_var.val_.getType() != capnp::DynamicValue::STRUCT) {
return error("Could not cast to a struct.");
}
return InputObjectType{_var.val_.as<capnp::DynamicStruct>()};
}
rfl::Result<InputMapType> to_map(const InputVarType& _var) const noexcept {
if (_var.val_.getType() != capnp::DynamicValue::STRUCT) {
return error("Could not cast to a map.");
}
return InputMapType{_var.val_.as<capnp::DynamicStruct>()};
}
rfl::Result<InputUnionType> to_union(
const InputVarType& _var) const noexcept {
if (_var.val_.getType() != capnp::DynamicValue::STRUCT) {
return error("Could not cast to a struct.");
}
return InputUnionType{_var.val_.as<capnp::DynamicStruct>()};
}
template <class ArrayReader>
std::optional<Error> read_array(const ArrayReader& _array_reader,
const InputArrayType& _arr) const noexcept {
for (auto element : _arr.val_) {
const auto err = _array_reader.read(InputVarType{std::move(element)});
if (err) {
return err;
}
}
return std::nullopt;
}
template <class MapReader>
std::optional<Error> read_map(const MapReader& _map_reader,
const InputMapType& _map) const noexcept {
try {
const auto entries = _map.val_.get("entries").as<capnp::DynamicList>();
for (auto entry : entries) {
auto s = entry.template as<capnp::DynamicStruct>();
const char* key = s.get("key").as<capnp::Text>().cStr();
_map_reader.read(std::string_view(key), InputVarType{s.get("value")});
}
return std::nullopt;
} catch (std::exception& e) {
return Error{e.what()};
}
}
template <class ObjectReader>
std::optional<Error> read_object(const ObjectReader& _object_reader,
const InputObjectType& _obj) const noexcept {
int i = 0;
for (auto field : _obj.val_.getSchema().getFields()) {
_object_reader.read(i++, InputVarType{_obj.val_.get(field)});
}
return std::nullopt;
}
template <class VariantType, class UnionReaderType>
rfl::Result<VariantType> read_union(
const InputUnionType& _union) const noexcept {
const auto opt_pair = identify_discriminant(_union);
if (!opt_pair) {
return error("Could not get the discriminant.");
}
const auto& [field, disc] = *opt_pair;
return UnionReaderType::read(*this, disc,
InputVarType{_union.val_.get(field)});
}
template <class T>
rfl::Result<T> use_custom_constructor(
const InputVarType& _var) const noexcept {
try {
return T::from_capnproto_obj(_var);
} catch (std::exception& e) {
return error(e.what());
}
}
private:
std::optional<std::pair<capnp::StructSchema::Field, size_t>>
identify_discriminant(const InputUnionType& _union) const noexcept;
};
} // namespace rfl::capnproto
#endif
|
