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 // Author: kenton@google.com (Kenton Varda)
32 // Based on original Protocol Buffers design by
33 // Sanjay Ghemawat, Jeff Dean, and others.
34 //
35 // Contains classes used to keep track of unrecognized fields seen while
36 // parsing a protocol message.
37
38 #ifndef GOOGLE_PROTOBUF_UNKNOWN_FIELD_SET_H__
39 #define GOOGLE_PROTOBUF_UNKNOWN_FIELD_SET_H__
40
41 #include <assert.h>
42 #include <string>
43 #include <vector>
44 #include <google/protobuf/stubs/common.h>
45 #include <google/protobuf/stubs/logging.h>
46
47 namespace google {
48 namespace protobuf {
49 namespace io {
50 class CodedInputStream; // coded_stream.h
51 class CodedOutputStream; // coded_stream.h
52 class ZeroCopyInputStream; // zero_copy_stream.h
53 }
54 namespace internal {
55 class WireFormat; // wire_format.h
56 class MessageSetFieldSkipperUsingCord;
57 // extension_set_heavy.cc
58 }
59
60 class Message; // message.h
61 class UnknownField; // below
62
63 // An UnknownFieldSet contains fields that were encountered while parsing a
64 // message but were not defined by its type. Keeping track of these can be
65 // useful, especially in that they may be written if the message is serialized
66 // again without being cleared in between. This means that software which
67 // simply receives messages and forwards them to other servers does not need
68 // to be updated every time a new field is added to the message definition.
69 //
70 // To get the UnknownFieldSet attached to any message, call
71 // Reflection::GetUnknownFields().
72 //
73 // This class is necessarily tied to the protocol buffer wire format, unlike
74 // the Reflection interface which is independent of any serialization scheme.
75 class LIBPROTOBUF_EXPORT UnknownFieldSet {
76 public:
77 UnknownFieldSet();
78 ~UnknownFieldSet();
79
80 // Remove all fields.
81 inline void Clear();
82
83 // Remove all fields and deallocate internal data objects
84 void ClearAndFreeMemory();
85
86 // Is this set empty?
87 inline bool empty() const;
88
89 // Merge the contents of some other UnknownFieldSet with this one.
90 void MergeFrom(const UnknownFieldSet& other);
91
92 // Similar to above, but this function will destroy the contents of other.
93 void MergeFromAndDestroy(UnknownFieldSet* other);
94
95 // Swaps the contents of some other UnknownFieldSet with this one.
96 inline void Swap(UnknownFieldSet* x);
97
98 // Computes (an estimate of) the total number of bytes currently used for
99 // storing the unknown fields in memory. Does NOT include
100 // sizeof(*this) in the calculation.
101 int SpaceUsedExcludingSelf() const;
102
103 // Version of SpaceUsed() including sizeof(*this).
104 int SpaceUsed() const;
105
106 // Returns the number of fields present in the UnknownFieldSet.
107 inline int field_count() const;
108 // Get a field in the set, where 0 <= index < field_count(). The fields
109 // appear in the order in which they were added.
110 inline const UnknownField& field(int index) const;
111 // Get a mutable pointer to a field in the set, where
112 // 0 <= index < field_count(). The fields appear in the order in which
113 // they were added.
114 inline UnknownField* mutable_field(int index);
115
116 // Adding fields ---------------------------------------------------
117
118 void AddVarint(int number, uint64 value);
119 void AddFixed32(int number, uint32 value);
120 void AddFixed64(int number, uint64 value);
121 void AddLengthDelimited(int number, const string& value);
122 string* AddLengthDelimited(int number);
123 UnknownFieldSet* AddGroup(int number);
124
125 // Adds an unknown field from another set.
126 void AddField(const UnknownField& field);
127
128 // Delete fields with indices in the range [start .. start+num-1].
129 // Caution: implementation moves all fields with indices [start+num .. ].
130 void DeleteSubrange(int start, int num);
131
132 // Delete all fields with a specific field number. The order of left fields
133 // is preserved.
134 // Caution: implementation moves all fields after the first deleted field.
135 void DeleteByNumber(int number);
136
137 // Parsing helpers -------------------------------------------------
138 // These work exactly like the similarly-named methods of Message.
139
140 bool MergeFromCodedStream(io::CodedInputStream* input);
141 bool ParseFromCodedStream(io::CodedInputStream* input);
142 bool ParseFromZeroCopyStream(io::ZeroCopyInputStream* input);
143 bool ParseFromArray(const void* data, int size);
ParseFromString(const string & data)144 inline bool ParseFromString(const string& data) {
145 return ParseFromArray(data.data(), static_cast<int>(data.size()));
146 }
147
148 static const UnknownFieldSet* default_instance();
149 private:
150 // For InternalMergeFrom
151 friend class UnknownField;
152 // Merges from other UnknownFieldSet. This method assumes, that this object
153 // is newly created and has fields_ == NULL;
154 void InternalMergeFrom(const UnknownFieldSet& other);
155 void ClearFallback();
156
157 // fields_ is either NULL, or a pointer to a vector that is *non-empty*. We
158 // never hold the empty vector because we want the 'do we have any unknown
159 // fields' check to be fast, and avoid a cache miss: the UFS instance gets
160 // embedded in the message object, so 'fields_ != NULL' tests a member
161 // variable hot in the cache, without the need to go touch a vector somewhere
162 // else in memory.
163 std::vector<UnknownField>* fields_;
164 GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(UnknownFieldSet);
165 };
166
167 // Represents one field in an UnknownFieldSet.
168 class LIBPROTOBUF_EXPORT UnknownField {
169 public:
170 enum Type {
171 TYPE_VARINT,
172 TYPE_FIXED32,
173 TYPE_FIXED64,
174 TYPE_LENGTH_DELIMITED,
175 TYPE_GROUP
176 };
177
178 // The field's tag number, as seen on the wire.
179 inline int number() const;
180
181 // The field type.
182 inline Type type() const;
183
184 // Accessors -------------------------------------------------------
185 // Each method works only for UnknownFields of the corresponding type.
186
187 inline uint64 varint() const;
188 inline uint32 fixed32() const;
189 inline uint64 fixed64() const;
190 inline const string& length_delimited() const;
191 inline const UnknownFieldSet& group() const;
192
193 inline void set_varint(uint64 value);
194 inline void set_fixed32(uint32 value);
195 inline void set_fixed64(uint64 value);
196 inline void set_length_delimited(const string& value);
197 inline string* mutable_length_delimited();
198 inline UnknownFieldSet* mutable_group();
199
200 // Serialization API.
201 // These methods can take advantage of the underlying implementation and may
202 // archieve a better performance than using getters to retrieve the data and
203 // do the serialization yourself.
204 void SerializeLengthDelimitedNoTag(io::CodedOutputStream* output) const;
205 uint8* SerializeLengthDelimitedNoTagToArray(uint8* target) const;
206
207 inline int GetLengthDelimitedSize() const;
208
209 private:
210 friend class UnknownFieldSet;
211
212 // If this UnknownField contains a pointer, delete it.
213 void Delete();
214
215 // Reset all the underlying pointers to NULL. A special function to be only
216 // used while merging from a temporary UFS.
217 void Reset();
218
219 // Make a deep copy of any pointers in this UnknownField.
220 void DeepCopy(const UnknownField& other);
221
222 // Set the wire type of this UnknownField. Should only be used when this
223 // UnknownField is being created.
224 inline void SetType(Type type);
225
226 union LengthDelimited {
227 string* string_value_;
228 };
229
230 uint32 number_;
231 uint32 type_;
232 union {
233 uint64 varint_;
234 uint32 fixed32_;
235 uint64 fixed64_;
236 mutable union LengthDelimited length_delimited_;
237 UnknownFieldSet* group_;
238 };
239 };
240
241 // ===================================================================
242 // inline implementations
243
Clear()244 inline void UnknownFieldSet::Clear() {
245 if (fields_) {
246 ClearFallback();
247 }
248 }
249
empty()250 inline bool UnknownFieldSet::empty() const {
251 // Invariant: fields_ is never empty if present.
252 return !fields_;
253 }
254
Swap(UnknownFieldSet * x)255 inline void UnknownFieldSet::Swap(UnknownFieldSet* x) {
256 std::swap(fields_, x->fields_);
257 }
258
field_count()259 inline int UnknownFieldSet::field_count() const {
260 return fields_ ? static_cast<int>(fields_->size()) : 0;
261 }
field(int index)262 inline const UnknownField& UnknownFieldSet::field(int index) const {
263 GOOGLE_DCHECK(fields_ != NULL);
264 return (*fields_)[index];
265 }
mutable_field(int index)266 inline UnknownField* UnknownFieldSet::mutable_field(int index) {
267 return &(*fields_)[index];
268 }
269
AddLengthDelimited(int number,const string & value)270 inline void UnknownFieldSet::AddLengthDelimited(
271 int number, const string& value) {
272 AddLengthDelimited(number)->assign(value);
273 }
274
275
number()276 inline int UnknownField::number() const { return number_; }
type()277 inline UnknownField::Type UnknownField::type() const {
278 return static_cast<Type>(type_);
279 }
280
varint()281 inline uint64 UnknownField::varint() const {
282 assert(type() == TYPE_VARINT);
283 return varint_;
284 }
fixed32()285 inline uint32 UnknownField::fixed32() const {
286 assert(type() == TYPE_FIXED32);
287 return fixed32_;
288 }
fixed64()289 inline uint64 UnknownField::fixed64() const {
290 assert(type() == TYPE_FIXED64);
291 return fixed64_;
292 }
length_delimited()293 inline const string& UnknownField::length_delimited() const {
294 assert(type() == TYPE_LENGTH_DELIMITED);
295 return *length_delimited_.string_value_;
296 }
group()297 inline const UnknownFieldSet& UnknownField::group() const {
298 assert(type() == TYPE_GROUP);
299 return *group_;
300 }
301
set_varint(uint64 value)302 inline void UnknownField::set_varint(uint64 value) {
303 assert(type() == TYPE_VARINT);
304 varint_ = value;
305 }
set_fixed32(uint32 value)306 inline void UnknownField::set_fixed32(uint32 value) {
307 assert(type() == TYPE_FIXED32);
308 fixed32_ = value;
309 }
set_fixed64(uint64 value)310 inline void UnknownField::set_fixed64(uint64 value) {
311 assert(type() == TYPE_FIXED64);
312 fixed64_ = value;
313 }
set_length_delimited(const string & value)314 inline void UnknownField::set_length_delimited(const string& value) {
315 assert(type() == TYPE_LENGTH_DELIMITED);
316 length_delimited_.string_value_->assign(value);
317 }
mutable_length_delimited()318 inline string* UnknownField::mutable_length_delimited() {
319 assert(type() == TYPE_LENGTH_DELIMITED);
320 return length_delimited_.string_value_;
321 }
mutable_group()322 inline UnknownFieldSet* UnknownField::mutable_group() {
323 assert(type() == TYPE_GROUP);
324 return group_;
325 }
326
GetLengthDelimitedSize()327 inline int UnknownField::GetLengthDelimitedSize() const {
328 GOOGLE_DCHECK_EQ(TYPE_LENGTH_DELIMITED, type());
329 return static_cast<int>(length_delimited_.string_value_->size());
330 }
331
SetType(Type type)332 inline void UnknownField::SetType(Type type) {
333 type_ = type;
334 }
335
336
337 } // namespace protobuf
338
339 } // namespace google
340 #endif // GOOGLE_PROTOBUF_UNKNOWN_FIELD_SET_H__
341