1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 //     * Redistributions of source code must retain the above copyright
10 // notice, this list of conditions and the following disclaimer.
11 //     * Redistributions in binary form must reproduce the above
12 // copyright notice, this list of conditions and the following disclaimer
13 // in the documentation and/or other materials provided with the
14 // distribution.
15 //     * Neither the name of Google Inc. nor the names of its
16 // contributors may be used to endorse or promote products derived from
17 // this software without specific prior written permission.
18 //
19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 
31 #ifndef GOOGLE_PROTOBUF_MAP_FIELD_LITE_H__
32 #define GOOGLE_PROTOBUF_MAP_FIELD_LITE_H__
33 
34 #include <type_traits>
35 #include <google/protobuf/parse_context.h>
36 #include <google/protobuf/io/coded_stream.h>
37 #include <google/protobuf/map.h>
38 #include <google/protobuf/map_entry_lite.h>
39 #include <google/protobuf/port.h>
40 #include <google/protobuf/wire_format_lite.h>
41 
42 #include <google/protobuf/port_def.inc>
43 
44 #ifdef SWIG
45 #error "You cannot SWIG proto headers"
46 #endif
47 
48 namespace google {
49 namespace protobuf {
50 namespace internal {
51 
52 // This class provides access to map field using generated api. It is used for
53 // internal generated message implentation only. Users should never use this
54 // directly.
55 template <typename Derived, typename Key, typename T,
56           WireFormatLite::FieldType key_wire_type,
57           WireFormatLite::FieldType value_wire_type, int default_enum_value = 0>
58 class MapFieldLite {
59   // Define message type for internal repeated field.
60   typedef Derived EntryType;
61 
62  public:
63   typedef Map<Key, T> MapType;
64   typedef EntryType EntryTypeTrait;
65 
MapFieldLite()66   MapFieldLite() : arena_(NULL) { SetDefaultEnumValue(); }
67 
MapFieldLite(Arena * arena)68   explicit MapFieldLite(Arena* arena) : arena_(arena), map_(arena) {
69     SetDefaultEnumValue();
70   }
71 
72   // Accessors
GetMap()73   const Map<Key, T>& GetMap() const { return map_; }
MutableMap()74   Map<Key, T>* MutableMap() { return &map_; }
75 
76   // Convenient methods for generated message implementation.
size()77   int size() const { return static_cast<int>(map_.size()); }
Clear()78   void Clear() { return map_.clear(); }
MergeFrom(const MapFieldLite & other)79   void MergeFrom(const MapFieldLite& other) {
80     for (typename Map<Key, T>::const_iterator it = other.map_.begin();
81          it != other.map_.end(); ++it) {
82       map_[it->first] = it->second;
83     }
84   }
Swap(MapFieldLite * other)85   void Swap(MapFieldLite* other) { map_.swap(other->map_); }
86 
87   // Set default enum value only for proto2 map field whose value is enum type.
SetDefaultEnumValue()88   void SetDefaultEnumValue() {
89     MutableMap()->SetDefaultEnumValue(default_enum_value);
90   }
91 
92   // Used in the implementation of parsing. Caller should take the ownership iff
93   // arena_ is NULL.
NewEntry()94   EntryType* NewEntry() const {
95     if (arena_ == NULL) {
96       return new EntryType();
97     } else {
98       return Arena::CreateMessage<EntryType>(arena_);
99     }
100   }
101   // Used in the implementation of serializing enum value type. Caller should
102   // take the ownership iff arena_ is NULL.
NewEnumEntryWrapper(const Key & key,const T t)103   EntryType* NewEnumEntryWrapper(const Key& key, const T t) const {
104     return EntryType::EnumWrap(key, t, arena_);
105   }
106   // Used in the implementation of serializing other value types. Caller should
107   // take the ownership iff arena_ is NULL.
NewEntryWrapper(const Key & key,const T & t)108   EntryType* NewEntryWrapper(const Key& key, const T& t) const {
109     return EntryType::Wrap(key, t, arena_);
110   }
111 
_InternalParse(const char * ptr,ParseContext * ctx)112   const char* _InternalParse(const char* ptr, ParseContext* ctx) {
113     typename Derived::template Parser<MapFieldLite, Map<Key, T>> parser(this);
114     return parser._InternalParse(ptr, ctx);
115   }
116 
117   template <typename Metadata>
ParseWithEnumValidation(const char * ptr,ParseContext * ctx,bool (* is_valid)(int),uint32 field_num,Metadata * metadata)118   const char* ParseWithEnumValidation(const char* ptr, ParseContext* ctx,
119                                       bool (*is_valid)(int), uint32 field_num,
120                                       Metadata* metadata) {
121     typename Derived::template Parser<MapFieldLite, Map<Key, T>> parser(this);
122     return parser.ParseWithEnumValidation(ptr, ctx, is_valid, field_num,
123                                           metadata);
124   }
125 
126  private:
127   typedef void DestructorSkippable_;
128 
129   Arena* arena_;
130   Map<Key, T> map_;
131 
132   friend class ::PROTOBUF_NAMESPACE_ID::Arena;
133 };
134 
135 template <typename T, typename Metadata>
136 struct EnumParseWrapper {
_InternalParseEnumParseWrapper137   const char* _InternalParse(const char* ptr, ParseContext* ctx) {
138     return map_field->ParseWithEnumValidation(ptr, ctx, is_valid, field_num,
139                                               metadata);
140   }
141   T* map_field;
142   bool (*is_valid)(int);
143   uint32 field_num;
144   Metadata* metadata;
145 };
146 
147 // Helper function because the typenames of maps are horrendous to print. This
148 // leverages compiler type deduction, to keep all type data out of the
149 // generated code
150 template <typename T, typename Metadata>
InitEnumParseWrapper(T * map_field,bool (* is_valid)(int),uint32 field_num,Metadata * metadata)151 EnumParseWrapper<T, Metadata> InitEnumParseWrapper(T* map_field,
152                                                    bool (*is_valid)(int),
153                                                    uint32 field_num,
154                                                    Metadata* metadata) {
155   return EnumParseWrapper<T, Metadata>{map_field, is_valid, field_num,
156                                        metadata};
157 }
158 
159 // True if IsInitialized() is true for value field in all elements of t. T is
160 // expected to be message.  It's useful to have this helper here to keep the
161 // protobuf compiler from ever having to emit loops in IsInitialized() methods.
162 // We want the C++ compiler to inline this or not as it sees fit.
163 template <typename Key, typename T>
AllAreInitialized(const Map<Key,T> & t)164 bool AllAreInitialized(const Map<Key, T>& t) {
165   for (typename Map<Key, T>::const_iterator it = t.begin(); it != t.end();
166        ++it) {
167     if (!it->second.IsInitialized()) return false;
168   }
169   return true;
170 }
171 
172 template <typename MEntry>
173 struct MapEntryToMapField : MapEntryToMapField<typename MEntry::SuperType> {};
174 
175 template <typename T, typename Key, typename Value,
176           WireFormatLite::FieldType kKeyFieldType,
177           WireFormatLite::FieldType kValueFieldType, int default_enum_value>
178 struct MapEntryToMapField<MapEntryLite<T, Key, Value, kKeyFieldType,
179                                        kValueFieldType, default_enum_value>> {
180   typedef MapFieldLite<MapEntryLite<T, Key, Value, kKeyFieldType,
181                                     kValueFieldType, default_enum_value>,
182                        Key, Value, kKeyFieldType, kValueFieldType,
183                        default_enum_value>
184       MapFieldType;
185 };
186 
187 }  // namespace internal
188 }  // namespace protobuf
189 }  // namespace google
190 
191 #include <google/protobuf/port_undef.inc>
192 
193 #endif  // GOOGLE_PROTOBUF_MAP_FIELD_LITE_H__
194