1 // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
2 // Licensed under the MIT License:
3 //
4 // Permission is hereby granted, free of charge, to any person obtaining a copy
5 // of this software and associated documentation files (the "Software"), to deal
6 // in the Software without restriction, including without limitation the rights
7 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 // copies of the Software, and to permit persons to whom the Software is
9 // furnished to do so, subject to the following conditions:
10 //
11 // The above copyright notice and this permission notice shall be included in
12 // all copies or substantial portions of the Software.
13 //
14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 // THE SOFTWARE.
21 
22 #pragma once
23 
24 #include "layout.h"
25 #include "list.h"
26 
27 CAPNP_BEGIN_HEADER
28 
29 namespace capnp {
30 namespace _ {  // private
31 
32 // PointerHelpers is a template class that assists in wrapping/unwrapping the low-level types in
33 // layout.h with the high-level public API and generated types.  This way, the code generator
34 // and other templates do not have to specialize on each kind of pointer.
35 
36 template <typename T>
37 struct PointerHelpers<T, Kind::STRUCT> {
38   static inline typename T::Reader get(PointerReader reader, const word* defaultValue = nullptr) {
39     return typename T::Reader(reader.getStruct(defaultValue));
40   }
41   static inline typename T::Builder get(PointerBuilder builder,
42                                         const word* defaultValue = nullptr) {
43     return typename T::Builder(builder.getStruct(structSize<T>(), defaultValue));
44   }
45   static inline void set(PointerBuilder builder, typename T::Reader value) {
46     builder.setStruct(value._reader);
47   }
48   static inline void setCanonical(PointerBuilder builder, typename T::Reader value) {
49     builder.setStruct(value._reader, true);
50   }
51   static inline typename T::Builder init(PointerBuilder builder) {
52     return typename T::Builder(builder.initStruct(structSize<T>()));
53   }
54   static inline void adopt(PointerBuilder builder, Orphan<T>&& value) {
55     builder.adopt(kj::mv(value.builder));
56   }
57   static inline Orphan<T> disown(PointerBuilder builder) {
58     return Orphan<T>(builder.disown());
59   }
60   static inline _::StructReader getInternalReader(const typename T::Reader& reader) {
61     return reader._reader;
62   }
63   static inline _::StructBuilder getInternalBuilder(typename T::Builder&& builder) {
64     return builder._builder;
65   }
66 };
67 
68 template <typename T>
69 struct PointerHelpers<List<T>, Kind::LIST> {
70   static inline typename List<T>::Reader get(PointerReader reader,
71                                              const word* defaultValue = nullptr) {
72     return typename List<T>::Reader(List<T>::getFromPointer(reader, defaultValue));
73   }
74   static inline typename List<T>::Builder get(PointerBuilder builder,
75                                               const word* defaultValue = nullptr) {
76     return typename List<T>::Builder(List<T>::getFromPointer(builder, defaultValue));
77   }
78   static inline void set(PointerBuilder builder, typename List<T>::Reader value) {
79     builder.setList(value.reader);
80   }
81   static inline void setCanonical(PointerBuilder builder, typename List<T>::Reader value) {
82     builder.setList(value.reader, true);
83   }
84   static void set(PointerBuilder builder, kj::ArrayPtr<const ReaderFor<T>> value) {
85     auto l = init(builder, value.size());
86     uint i = 0;
87     for (auto& element: value) {
88       l.set(i++, element);
89     }
90   }
91   static inline typename List<T>::Builder init(PointerBuilder builder, uint size) {
92     return typename List<T>::Builder(List<T>::initPointer(builder, size));
93   }
94   static inline void adopt(PointerBuilder builder, Orphan<List<T>>&& value) {
95     builder.adopt(kj::mv(value.builder));
96   }
97   static inline Orphan<List<T>> disown(PointerBuilder builder) {
98     return Orphan<List<T>>(builder.disown());
99   }
100   static inline _::ListReader getInternalReader(const typename List<T>::Reader& reader) {
101     return reader.reader;
102   }
103   static inline _::ListBuilder getInternalBuilder(typename List<T>::Builder&& builder) {
104     return builder.builder;
105   }
106 };
107 
108 template <typename T>
109 struct PointerHelpers<T, Kind::BLOB> {
110   static inline typename T::Reader get(PointerReader reader,
111                                        const void* defaultValue = nullptr,
112                                        uint defaultBytes = 0) {
113     return reader.getBlob<T>(defaultValue, bounded(defaultBytes) * BYTES);
114   }
115   static inline typename T::Builder get(PointerBuilder builder,
116                                         const void* defaultValue = nullptr,
117                                         uint defaultBytes = 0) {
118     return builder.getBlob<T>(defaultValue, bounded(defaultBytes) * BYTES);
119   }
120   static inline void set(PointerBuilder builder, typename T::Reader value) {
121     builder.setBlob<T>(value);
122   }
123   static inline void setCanonical(PointerBuilder builder, typename T::Reader value) {
124     builder.setBlob<T>(value);
125   }
126   static inline typename T::Builder init(PointerBuilder builder, uint size) {
127     return builder.initBlob<T>(bounded(size) * BYTES);
128   }
129   static inline void adopt(PointerBuilder builder, Orphan<T>&& value) {
130     builder.adopt(kj::mv(value.builder));
131   }
132   static inline Orphan<T> disown(PointerBuilder builder) {
133     return Orphan<T>(builder.disown());
134   }
135 };
136 
137 struct UncheckedMessage {
138   typedef const word* Reader;
139 };
140 
141 template <> struct Kind_<UncheckedMessage> { static constexpr Kind kind = Kind::OTHER; };
142 
143 template <>
144 struct PointerHelpers<UncheckedMessage> {
145   // Reads an AnyPointer field as an unchecked message pointer.  Requires that the containing
146   // message is itself unchecked.  This hack is currently private.  It is used to locate default
147   // values within encoded schemas.
148 
149   static inline const word* get(PointerReader reader) {
150     return reader.getUnchecked();
151   }
152 };
153 
154 }  // namespace _ (private)
155 }  // namespace capnp
156 
157 CAPNP_END_HEADER
158